FIELD

The present invention relates to an apparatus for interaction with a modular structure and a discrete motion system in which said apparatus is employed.

BACKGROUND

In construction environments, a constraint of common-place 'industrial robots' is a restricted, or fixed, working zone of such robots: they have a fixed base so can operate only to within a limited distance of the fixed base. An alternative for assembling structures is larger scale equipment such as, for example, cranes or overhead gantries. However, these can be inflexible, may have high fixed costs, and may be limited in what they can build.

Construction may be simplified by introducing modularity into structural components and means of assembly. An area of robotics has evolved in construction of this type - "distributed robotics" - where multiple robots are able to manipulate modular structural components and move over a structure (formed from such modular structural components) that they are building, collaborating in the overall construction effort and not bound by any size limit. Such robots collect modular structural components from a supply area and carry them to a construction area of the structure. An area on which the robots can move dynamically expands during the construction process as more modular structural components are added.

The present invention has been devised with the foregoing considerations in mind.

SUMMARY

According to an aspect of the present invention, there is provided a discrete motion system, comprising: a modular structure, the modular structure comprising a plurality of units, each unit comprising a regular configuration of attachment points; and an apparatus for interaction with a modular structure, the apparatus comprising: a chassis; a first foot member coupled to said chassis and a second foot member coupled to said chassis, said first and second foot members coupled to said chassis by respective first and second coupling elements operative to permit relative movement between the first foot member and the chassis, and the second foot member and the chassis; said first and second foot member each comprising an attachment member configured to engage with units of said modular structure via cooperative engagement of said attachment members with attachment points of said units; a third foot member coupled to said chassis by a third coupling element, said third coupling element operative to permit relative movement between the third foot member and the chassis, said third foot member comprising an attachment member operative to releasably couple said third foot member to one of: a unit to be added to said modular structure; and a unit to be removed from said modular structure, via cooperative engagement of said attachment member with an attachment point of said unit; the apparatus operative to engage with said modular structure via said first and second foot members, and move relative to said modular structure in discrete increments defined by a regular configuration of attachment points on units of said modular structure.

Optionally, the apparatus may be operative to add a unit to said plurality of connected units of said modular structure by: controlling said third foot member to engage with a unit to be added to said plurality of connected units; alternately engaging said modular structure with said first and second foot members to effect movement of said apparatus to a position on said modular structure in a vicinity of a placement position where said unit to be added is to be located; and controlling said third foot member to locate said unit to be added in said placement position.

Optionally, the apparatus may be operative to remove a unit from said plurality of connected units of said modular structure by: alternately engaging said modular structure with said first and second foot members to effect movement of said apparatus to a position on said modular structure in a vicinity of a removal position from where a unit to be removed is located; controlling said third foot member to engage with said unit to be removed; and controlling said third foot member to remove said unit to be removed from said removal position.

Optionally, a configuration of the first, second and/or third coupling element may be controllable to control orientation of respective first, second and/or third foot members relative to said chassis and/or to control spacing of said respective first, second and/or third foot members from said chassis. Further optionally, the first coupling element and/or the second coupling element may be controllable in three rotational degrees of freedom to permit relative movement between the first foot member and the chassis, and/or the second foot member and the chassis, in three rotational degrees of freedom. Yet further optionally, the first coupling element and/or the second coupling element may be further controllable in one translational degree of freedom to alter a spacing between said attachment member of said first foot member and said first coupling element, and/or a spacing between said attachment member of said second foot member and said second coupling element. Also, the third coupling element may be controllable in three rotational degrees of freedom to permit relative movement between the third foot member and the chassis in three rotational degrees of freedom. Optionally, the third coupling element may be controllable in one rotational degree of freedom to permit relative movement between the third foot member and the chassis in one rotational degree of freedom.

Optionally, the third coupling element may be further controllable in one translational degree of freedom to alter a spacing between said attachment member of said third foot member and said third coupling element.

Optionally, movement of the first, second and/or third coupling elements relative to said chassis may be controllable to move said respective first, second and third coupling elements along said chassis, or to move said chassis relative to said first, second and/or third coupling elements. Optionally, the relative movement may comprise a sliding movement of said respective first, second and third coupling elements along said chassis.

Optionally, the chassis may comprise an elongate member with first and second ends, and further wherein said first foot member may be coupled to the chassis at, or toward, a first end of said chassis, and said second foot member may be coupled to the chassis at, or toward, a second end of said chassis.

Optionally, the first and/or second coupling elements may be controllable to alter a coupling position thereof relative to respective first and/or second ends of said chassis.

Optionally, the third foot member may be coupled to the chassis at, or toward, a mid-point of said chassis between said first and second ends.

Optionally, the third foot member may be fixedly coupled to said chassis at said mid-point.

Optionally, the third coupling element may be controllable to alter a coupling position thereof relative to respective first and/or second ends of said chassis.

Optionally, the third coupling element may be further controllable to alter a coupling position thereof relative to a coupling position of said first coupling element and/or said second coupling element.

Optionally the attachment member may comprise: a contact surface for placement against a surface of a unit for said modular structure; an engagement element disposed on said contact surface and configured for mutually cooperative interengagement with an attachment point of said unit. Further optionally, the engagement element may be controllable to cause engagement and disengagement of the attachment member from a unit of the modular structure. Yet further optionally, the engagement element may be controllably extendible from said contact surface to protrude therefrom. Also, the engagement element may comprise: a male engagement element to be received in and/or for engagement with a corresponding female element comprising an attachment point of a unit for said modular structure; and/or the engagement element may comprise a female engagement element for receiving and/or for engagement with a corresponding male element comprising an attachment point of a unit for said modular structure. Optionally, the male engagement element may comprise a shaft configured for insertion into a corresponding bore comprising said female element. The shaft may comprise a threaded shaft and the bore may comprise a threaded bore.

Optionally, the male engagement element may comprise a guide element at a tip thereof to guide said male engagement element into said female element during an insertion process.

Optionally, the attachment member may comprise at least two engagement elements, each engagement element individually controllable.

Optionally, the system may further comprise a mechanism operative to alter a length of said chassis. Optionally, the system may further comprise a fourth foot member coupled to said chassis by a fourth coupling element, said fourth coupling element operative to permit relative movement between the fourth foot member and the chassis, wherein said fourth foot member comprises an element operative to at least one of: couple a unit to be added to said modular structure, that is engaged with said third foot member, to a unit within said modular structure; de-couple a unit to be removed from said modular structure, that is engaged with said third foot member, from a unit within said modular structure.

Optionally, the first foot member and/or second foot member may comprise a removable attachment member. Further optionally, the third foot member may comprise a removable attachment member. Yet further optionally, a removable attachment member of a first type may be replaceable with a removable attachment member of a second type. This may allow the "feet" of the apparatus to be configured for engagement with different types of units, or bricks.

According to another aspect of the present invention, there is provided an apparatus for interaction with a modular structure, the modular structure comprising a plurality of units, each unit comprising a regular configuration of attachment points; the apparatus comprising: a chassis; a first foot member coupled to said chassis and a second foot member coupled to said chassis, said first and second foot members coupled to said chassis by respective first and second coupling elements operative to permit relative movement between the first foot member and the chassis, and the second foot member and the chassis; said first and second foot member each comprising an attachment member configured to engage with units of said modular structure via cooperative engagement of said attachment members with attachment points of said units; a third foot member coupled to said chassis by a third coupling element, said third coupling element operative to permit relative movement between the third foot member and the chassis, said third foot member comprising an attachment member operative to releasably couple said third foot member to one of: a unit to be added to said modular structure; and a unit to be removed from said modular structure, via cooperative engagement of said attachment member with an attachment point of said unit; the apparatus operative to engage with said modular structure via said first and second foot members, and move relative to said modular structure in discrete increments defined by a regular configuration of attachment points on units of said modular structure.

Optionally, the apparatus may be operative to add a unit to said plurality of connected units of said modular structure by: controlling said third foot member to engage with a unit to be added to said plurality of connected units; alternately engaging said modular structure with said first and second foot members to effect movement of said apparatus to a position on said modular structure in a vicinity of a placement position where said unit to be added is to be located; and controlling said third foot member to locate said unit to be added in said placement position.

Optionally, the apparatus may be operative to remove a unit from said plurality of connected units of said modular structure by: alternately engaging said modular structure with said first and second foot members to effect movement of said apparatus to a position on said modular structure in a vicinity of a removal position from where a unit to be removed is located; controlling said third foot member to engage with said unit to be removed; and controlling said third foot member to remove said unit to be removed from said removal position.

Optionally, a configuration of said first, second and/or third coupling element may be controllable to control orientation of respective first, second and/or third foot members relative to said chassis and/or to control spacing of said respective first, second and/or third foot members from said chassis.

Optionally, the first coupling element and/or said second coupling element may be controllable in three rotational degrees of freedom to permit relative movement between the first foot member and the chassis, and/or the second foot member and the chassis, in three rotational degrees of freedom.

Optionally, the first coupling element and/or said second coupling element may be further controllable in one translational degree of freedom to alter a spacing between said attachment member of said first foot member and said first coupling element, and/or a spacing between said attachment member of said second foot member and said second coupling element.

Optionally, the third coupling element may be controllable in three rotational degrees of freedom to permit relative movement between the third foot member and the chassis in three rotational degrees of freedom.

Optionally, the third coupling element may be controllable in one rotational degree of freedom to permit relative movement between the third foot member and the chassis in one rotational degree of freedom.

Optionally, the third coupling element may be further controllable in one translational degree of freedom to alter a spacing between said attachment member of said third foot member and said third coupling element.

Optionally, movement of the first, second and/or third coupling elements relative to said chassis may be controllable to move said respective first, second and third coupling elements along said chassis, or to move said chassis relative to said first, second and/or third coupling elements.

Optionally, the relative movement may comprise a sliding movement of said respective first, second and third coupling elements along said chassis.

Optionally, the chassis may comprise an elongate member with first and second ends, and further wherein said first foot member may be coupled to the chassis at, or toward, a first end of said chassis, and said second foot member may be coupled to the chassis at, or toward, a second end of said chassis.

Optionally, first and/or second coupling elements may be controllable to alter a coupling position thereof relative to respective first and/or second ends of said chassis. Optionally, the third foot member may be coupled to the chassis at, or toward, a mid-point of said chassis between said first and second ends.

Optionally, the third foot member may be fixedly coupled to said chassis at said mid-point.

Optionally, the third coupling element may be controllable to alter a coupling position thereof relative to respective first and/or second ends of said chassis.

Optionally, the third coupling element may be further controllable to alter a coupling position thereof relative to a coupling position of said first coupling element and/or said second coupling element.

Optionally, the attachment member may comprise: a contact surface for placement against a surface of a unit for said modular structure; an engagement element disposed on said contact surface and configured for mutually cooperative interengagement with an attachment point of said unit.

Optionally, the engagement element may be controllable to cause engagement and disengagement of the attachment member from a unit of the modular structure.

Optionally, the engagement element may be controllably extendible from said contact surface to protrude therefrom.

Optionally, the engagement element may comprise: a male engagement element to be received in and/or for engagement with a corresponding female element comprising an attachment point of a unit for said modular structure; and/or the engagement element may comprise a female engagement element for receiving and/or for engagement with a corresponding male element comprising an attachment point of a unit for said modular structure.

Optionally, the male engagement element may comprises a shaft configured for insertion into a corresponding bore comprising said female element.

Optionally, the shaft may comprise a threaded shaft and said bore may comprise a threaded bore.

Optionally, the male engagement element may comprise a guide element at a tip thereof to guide said male engagement element into said female element during an insertion process.

Optionally, the attachment member may comprise at least two engagement elements, each engagement element individually controllable.

Optionally, the apparatus may further comprise a mechanism operative to alter a length of said chassis.

Optionally, the apparatus may further comprise a fourth foot member coupled to said chassis by a fourth coupling element, said fourth coupling element operative to permit relative movement between the fourth foot member and the chassis, wherein said fourth foot member comprises an element operative to at least one of: couple a unit to be added to said modular structure, that is engaged with said third foot member, to a unit within said modular structure; de-couple a unit to be removed from said modular structure, that is engaged with said third foot member, from a unit within said modular structure. Optionally, the first foot member and/or second foot member may comprise a removable attachment member.

Optionally, the third foot member may comprise a removable attachment member.

Optionally, a removable attachment member of a first type may be replaceable with a removable attachment member of a second type.

According to another aspect of the present invention, there is provided an apparatus for interaction with a modular structure, comprising: a chassis comprising first and second ends; a first foot member mounted at a first end of said chassis and a second foot member mounted at a second end of said chassis, said first and second foot members mounted to respective said first and second ends of said chassis by respective first and second coupling elements operative to permit relative movement between the first foot and the chassis, and the second foot and the chassis, in three rotational degrees of freedom; said first and second foot member each comprising an attachment mechanism, or attachment member, operative to releasably couple said respective first and second foot member to units of a modular structure via cooperative engagement of said attachment mechanisms, or attachment members, with attachment points of said units; a third foot member mounted to said chassis by a third coupling element at a position between said first and second ends, said third coupling element operative to permit relative movement between the third foot and the chassis in one rotational degree of freedom and one translational degree of freedom, said third foot member comprising an attachment mechanism, or attachment member, operative to releasably couple said third foot member to a unit for a modular structure via cooperative engagement of said attachment mechanism, or attachment member, with an attachment point of said unit; the apparatus operative to engage with a modular structure via said first and second foot members, and move relative to a modular structure in discrete increments defined by a regular configuration of attachment points on units of said modular structure; and wherein said third foot member of said apparatus is further operative to engage with a unit for a modular structure and locate said unit in a position relative to said modular structure responsive to receipt of instructions defining the position relative to said modular structure where said unit is to be located.

Optionally, the apparatus may further comprise a first actuator, a second actuator and a third actuator, said first, second and third actuators operative to control configurations of respective said first, second and third coupling elements to control orientation of respective first, second and third foot members relative to said chassis. Further optionally, the third actuator may be further operative to control configuration of said third coupling element to control spacing of said third foot member from said chassis.

Optionally, the attachment mechanism, or attachment member, may comprise: a contact surface for placement against a surface of a unit for said modular structure; an engagement element disposed on said contact surface and configured for mutually cooperative interengagement with an attachment point of said unit, said engagement element responsive to instructions received to cause engagement and disengagement of the attachment mechanism, or attachment member, from a unit of the modular structure. Further optionally, the engagement element may be controllably extendible from said contact surface to protrude therefrom. Yet further optionally, the engagement element may comprise a male element for engagement with a corresponding female element comprising an attachment point of a unit for said modular structure, or said engagement element comprises a female element for engagement with a corresponding male element comprising an attachment point of a unit for said modular structure. The male element may comprise a threaded shaft configured for insertion into a corresponding threaded bore comprising the female element.

Optionally, the attachment mechanism, or attachment member, may comprise at least two engagement elements, each engagement element individually controllable.

Optionally, the first and second coupling elements may each comprise a wrist assembly. Optionally, the third coupling element may comprise a rotational assembly and a translation assembly.

Optionally, the apparatus may further comprise a mechanism operative to alter a length of the chassis.

Optionally, the apparatus may further comprise a fourth foot member mounted to said chassis by a fourth coupling element between said first and second ends, said fourth coupling element operative to permit relative movement between the fourth foot member and the chassis in three rotational degrees of freedom, wherein said fourth foot member of said apparatus may be further operative to couple a unit for a modular structure engaged with said third foot member to a unit within said modular structure.

Optionally, the apparatus may further comprise a controller which, responsive to receiving instructions, operates to control said apparatus to: engage with a modular structure via said first and second foot members; move relative to a modular structure in discreet increments defined by a regular configuration of attachment points on units of said modular structure; engage with a unit for a modular structure; and locate said unit in a position relative to said modular structure responsive to receipt of instructions defining the position relative to said modular structure where said unit is to be located.

According to another aspect of the present invention, there is provided a discrete motion system, comprising: a modular structure, the modular structure formed from a plurality of connected units, each unit comprising a regular configuration of attachment points; and an apparatus as described above and hereinafter, the apparatus operative to: engage with said modular structure via said first and second foot members; move relative to said modular structure in discreet increments defined by said regular configuration of attachment points on units of said modular structure; engage with a unit for location in said modular structure; and locate said unit in a position relative to said modular structure responsive to receipt of instructions defining the position relative to said modular structure where said unit is to be located.

According to another aspect of the present invention, there is provided a discrete motion system, comprising: a modular structure, the modular structure formed from a plurality of connected units, each unit comprising a regular configuration of attachment points; and an apparatus as described above and hereinafter, the apparatus operative to: engage with said modular structure via said first and second foot members; move relative to said modular structure in discreet increments defined by said regular configuration of attachment points on units of said modular structure; engage with a unit to be removed from said modular structure responsive to receipt of instructions defining a position of said unit in said modular structure; and remove said unit from said modular structure.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the present invention are described further hereinafter, by way of example only, with reference to the accompanying drawings in which:

FIG. la illustrates a perspective view of an apparatus for interaction with a modular structure according to one or more embodiments of the present invention;

FIG. lb illustrates a perspective view of an apparatus according to one or more embodiments of the present invention located upon a part of a modular structure;

FIG. 2a is a detailed perspective view of an underside of a foot member of the apparatus illustrating an attachment mechanism, or attachment member;

FIG. 2b is an illustrative schematic of an underside of a foot member of the apparatus showing parts of the attachment mechanism, or attachment member, of Fig. 2a;

FIG. 3a is a detailed perspective view of an underside of part of a foot member illustrating a connection unit of the apparatus according to one or more embodiments of the present invention;

FIG. 3b is a detailed side view of part of a foot member illustrating a connection unit of the apparatus according to one or more embodiments of the present invention and a unit for a modular structure;

FIG. 3c is detailed side view of part of a foot member illustrating a connection unit of the apparatus according to one or more embodiments of the present invention and a unit for a modular structure;

FIG. 3d detailed side view of part of a foot member illustrating a connection unit of the apparatus according to one or more embodiments of the present invention and a unit for a modular structure;

FIG. 4a is a detailed plan view of a foot member of an apparatus according to one or more embodiments of the present invention in a position for coupling to a unit for a modular structure;

FIG. 4b is an end view illustration of the apparatus and unit illustrated in FIG. 4a;

FIG. 4c is a side view illustration of the apparatus and unit illustrated in FIGS. 4a and 4b; FIG. 4d is a perspective top plan view illustration of the apparatus and unit illustrated in FIGS. 4a to 4c;

FIG. 5a is a detailed plan view of a foot member of an apparatus according to one or more embodiments of the present invention in a position in which the foot member is coupled to a unit for a modular structure;

FIG. 5b is an end view illustration of the apparatus and unit illustrated in FIG. 5a;

FIG. 5c is a side view illustration of the apparatus and unit illustrated in FIGS. 5a and 5b;

FIG. 5d is a perspective top plan view illustration of the apparatus and unit illustrated in FIGS. 5a to 5c;

FIG. 6 is a series of illustrative schematic side views of an apparatus according to one or more embodiments of the present invention in various positions relative to a modular structure;

FIG. 7 is a detailed perspective view illustrating part of the apparatus according to one or more embodiments of the present invention during a locating step of locating a unit against another unit;

FIG. 8a is a detailed perspective view illustrating an apparatus according to one or more embodiments of the present invention in an optional arrangement during a locating step of locating a unit against another unit; and

FIG. 8b is a perspective view illustrating the locating step of FIG. 8a in more detail;

FIG. 9a illustrates a perspective view of an apparatus for interaction with a modular structure according to another one or more embodiments of the present invention;

FIG. 9b illustrates a perspective view of the apparatus illustrated in FIG. 9b located upon a part of a modular structure;

FIG. 10 is a detailed perspective view of an underside of first and second foot members of the apparatus 100 illustrated in FIGS. 9a and 9b;

FIG. 11 is a detailed perspective view of an underside of a third foot member of the apparatus

100 illustrated in FIGS. 9a and 9b; and

FIG. 12 is a series of illustrative schematic side views of the apparatus illustrated in FIGS. 9a and 9b in various positions relative to a modular structure. DETAILED DESCRIPTION

FIG. la illustrates a perspective view of an apparatus 10 for interaction with a modular structure according to one or more embodiments of the present invention. The apparatus 10 comprises a chassis 12, which comprises an elongate element. At a first end 14a of the chassis 12, there is disposed a first foot member 16a. At a second end 14b of the chassis 12, there is disposed a second foot member 16b. First and second foot members 16a, 16b each comprise an attachment mechanism, or attachment member, that is operative to releasably couple the respective first and second foot members to a unit or units of a modular structure via cooperative engagement of the attachment members with attachment points of the units. The attachment mechanisms, or attachment members, of the foot members will be described in more detail later. Hereinafter, the attachment mechanisms/attachment members will be referred to simply as "attachment members" for convenience.

The first and second foot members 16a, 16b are mounted to respective first and second ends

14a, 14b of the chassis 12 by respective first and second coupling elements 18a, 18b operative to permit relative movement between the first foot member 16a and the chassis 12, and the second foot member 16b and the chassis 12. The first and second coupling elements 18a, 18b each comprise an assembly operative to pennit three rotational degrees of freedom of the foot members 16a, 16b relative to the chassis 12. In Fig. 1 a, a dashed circle is used to surround the elements that make up the assemblies of the first and second coupling elements 18a, 18b. For each of the first and second coupling elements 18a, 18b, the respective assemblies comprise three joints. These are denoted by 20a, 22a, 24a for first coupling element 18a and by 20b, 22b, 24b for second coupling element 18b. These types of assemblies are commonly known as "wrist assemblies" and each one of the joints respectively controls the "roll", "pitch" and "yaw". In the illustrated embodiment, first joints 20a, 20b, control rotation (denoted by arrow Rl) of the foot members relative to the chassis 12 about a z-axis. Similarly, second joints 22a, 22b control rotation (denoted by arrow R2) of the foot members relative to the chassis 12 about an x-axis, and third joints 24a, 24b control rotation (denoted by arrow R3) of the foot members relative to the chassis 12 about a y-axis. The combination of joints 20, 22 and 24 provide the three rotational degrees of freedom of the foot members 16a, 16b relative to the chassis 12.

The apparatus 10 also comprises a third foot member 16c that is mounted to the chassis 12 by a third coupling element 18c at a position between the first and second ends 14a, 14b. In the illustrated embodiment, the third coupling element 18c is located midway between the first and second ends 14a, 14b of the chassis 12, but, in optional arrangements, the third coupling element 18c could be "off-centre".

The third coupling element 18c comprises an assembly for permitting relative movement between the third foot member 16c and the chassis 12 in one rotational degree of freedom and one translational degree of freedom. In Fig. 1 a, a dashed circle is used to surround the elements that make up the assembly of the third coupling element 18c.

The assembly of the third coupling element 18c comprises a joint 26 for permitting rotational movement of the third foot member 16c relative to the chassis 12, and a translational element 28 for permitting translational movement of the third foot member 16c relative to the chassis 12 (i.e. alter the spacing between the third foot member 16c and chassis 12 by moving the foot member 16c closer to, or further away from the chassis 12). In the illustrated embodiment, joint 26 controls rotation (denoted by arrow R4) of the foot member 16c relative to the chassis 12 about an axis denoted "a". Translation element 28 controls translational movement (denoted by arrow Tl) of the foot member 16c relative to the chassis 12 along the axis "a".

The third foot member 16c comprises an attachment member operative to releasably couple the third foot member 16c to a unit for a modular structure via cooperative engagement of the attachment member with an attachment point of the unit. The attachment member of the third foot member 16c will be described in more detail later.

The first and second foot members 16a, 16b are operative to attach to units of a modular structure and can permit locomotion , or traversal, of the apparatus 10 relative to the modular structure (e.g. over, across, and/or along the modular structure). The third foot member 16c is operative to attach to a unit that is to be added to, or removed from, a modular structure. For example, the apparatus 10 may be located at a unit supply area where a unit for addition to a modular structure is collected by the apparatus 10 by engagement of the attachment member of the third foot member 16c with an attachment point of the unit to be added to the modular structure. Upon collection of the unit, the apparatus 10 can mount the modular structure and traverse the modular structure to a position adjacent where the unit is to be placed. The third foot member 16c is used to manipulate the unit to a correct orientation and is also used to place the unit into position in the modular structure. The first and second foot members 16a, 16b may also be used to orient the apparatus 10 relative to the modular structure to minimise an amount of manipulation of the unit undertaken by the third foot member 16c. This process will be further described later in relation to Fig. 6.

In an optional arrangement, the chassis 12 may include a translational joint to allow the length of the chassis 12 to be altered (e.g. to alter the spacing between the first and second foot members 16a, 16b, if required).

In Fig. lb, the apparatus 10 is shown upon part of a modular structure. In the illustrated example, the first foot member 16a is mounted upon (and connected to) a first unit 30 of the modular structure. The third foot member 16c is coupled to a second unit 32. The second unit 32 is a unit to be located in the modular structure. The third foot member 16c allows unit 32 to be manoeuvred into a position in the modular structure where the unit 32 can be secured to another part, or other parts, of the modular structure. The configuration of the third coupling element 18c permits rotation of the third foot member 16c to provide rotational movement of unit 32 about an axis (i.e. axis "a") that is perpendicular to the longitudinal length of chassis 12. This allows the orientation of the unit 32 that is currently being placed in the modular structure to be manipulated so as to be oriented in a required manner relative to a unit (or units) in the modular structure (i.e. relative to unit 30 in Fig. lb, to which first foot member 16a is connected).

In a scenario where the first foot member 16a is connected to a first unit in a modular structure and the second foot member 16b is connected to a second unit in a modular structure, the configuration of the third coupling element 18c (i.e. offering translational and rotation movement) permits manipulation of a unit to which the third foot member 16c is connected even though both foot members 16a, 16b are connected to units in the modular structure. In the illustrated example, the third coupling element 18c (i.e. translational element 28 thereof) may be extended such that unit 32 can be moved downwards in a direction perpendicular to the longitudinal length of chassis 12.

The three rotational degrees of freedom provided by first and second coupling elements 18a, 18b confer a plurality of positions the unit 32 can be placed in and fixed relative to unit 30 as well as providing a number of traversal styles (or "gaits") that the apparatus 10 may adopt to move around the modular structure.

The units 30, 32 may form part of a modular structure that will be assembled by apparatus 10. In Fig. lb, the units are depicted as a cuboid shape. However, any suitable shape may be used. The units 30, 32 may be composed of any combination of self-supporting material such as wood, metal, composite or plastic.

Along edges 300 of the units 30, 32 there are provided attachment points. These may comprise a plurality of equally spaced recessed attachment points 302, which may be bolt holes or other suitable connection points. The attachment points may be used both for structural joint purposes and as an attachment point for the foot members of apparatus 10. In an optional arrangement, the attachment points 302 may be structurally rated to support the apparatus 10 and other units. When used for the purpose of structural joints a reversible rigid connection can be fonned between two units by use of a connecting plate or similar. The plate is formed such that when connecting two units it is flush with the surface of the two units.

The equally spaced attachment points 302 form a continuous path of attachment points for the apparatus and they may be uniquely indexed so that the apparatus may ascertain its position when attached to a unit. The numbering may be clockwise on each face with each face being sequentially ordered. This forms a continuous but quantifiable path for the apparatus to attach and manoeuvre relative to. The equally spaced attachment points 302 allow the apparatus 10 to secure itself on the modular structure and may also reduce the sophistication of motion planning when generating the instructions for the apparatus 10. The apparatus 10 can ascertain where it is on the modular structure by determining which attachment points 302 it is attached to. In an optional arrangement, the attachment points 302 are spaced 30mm apart, but other spacings may be employed in other arrangements.

It is in this manner that the apparatus 10 can attach itself to units of a modular structure and also pick-up and hold a unit for placement in the modular structure.

First, second and third foot members 16a, 16b, 16c each include an attachment member for connection to an attachment point of a unit. Fig. 2a is a detailed perspective view of an underside of a foot member of the apparatus illustrating an attachment member 33. The attachment member 33 includes an abutment plate 40, which defines a planar surface for placement against a surface of a unit for a modular structure. Abutment plate 40 comprises a planar element having a central region 41 from which extend arms 43. Connection units 42 are located at ends of said arms 43. In the illustrated embodiment, the abutment plate 40 comprises four arms 43 and four connection units 42, with each arm 43 having a connection unit 42 located at an end thereof.

The connection units include fixed locating pins 34 and moveable threaded rods 36. Provision of four connection units 42 in the attachment member 33 means that the foot member, which, preferably, has a generally quadrilateral shaped footprint, can have a connection unit located at each corner thereof. Therefore, the foot member can be connectable to a unit at four different attachment points of the unit.

In optional arrangements, the attachment members 33 of the foot members may have greater than four connection units. In other optional arrangements, the attachment members 33 of the foot members may have fewer than four connection units. For example, for a modular structure comprising triangular-shaped units and/or hexagonal-shaped units (e.g. facade cladding panels or panels of a geodesic dome), then it may be more suitable for the attachments mechanisms 33 of the foot members to have three connection units (e.g. one for each corner of a triangular-shaped unit and one for every other corner of a hexagonal-shaped unit).

The attachment member is configured such that the spacing between adjacent pairs of moveable threaded rods 36 corresponds to a spacing between a pair of attachment points 302 having an integer number of attachment points 302 therebetween.

FIG. 2b is an illustrative schematic of an underside of a foot member of the apparatus showing fewer parts of the attachment member than are illustrated in Fig. 2a. It shows the location of the attachment member on a foot member relative to an end of the chassis and shows some parts of the attachment member relative to the footprint of the foot member.

FIG. 3a is a detailed perspective view of an underside of part of a foot member illustrating one of the connection units 42 of the foot member.

The connection unit 42 comprises a frame 45, mounted at an end of an arm 43 of the abutment plate, on a side of the abutment plate that is opposite to a side for abutting a surface of a unit for a modular structure. The frame 45 supports a motor 44 and a coupling 46, and the motor 44 is coupled to threaded rod 36 via coupling 46. The threaded rod 36, motor 44 and coupling 46 effectively form a "traveling screw" arrangement, whereby threaded rod 36 can be extended from the surface of the abutment plate for abutting a surface of a unit for a modular structure and retracted therefrom through operation of the motor 44, which causes motor 44, coupling 46 and threaded rod 36 to move relative to frame 45 and to arm 43.

The threaded rod 36 is configured to be screwed into an attachment point 302 on a unit 30 and, once a foot member is suitably located so that an abutment surface thereof abuts a surface of the unit 30, the threaded rod 36 can be screwed into an attachment point by operating motor 45 to cause the threaded rod 36 to extend from the abutment surface into the attachment point 302. Fixed locating pin 34 aids in correctly locating the foot member on the unit 302. Steps in an attachment process of a foot member of the apparatus to a unit are illustrated in figures FIGS. 3b to 3d.

The detailed side view FIG. 3b illustrates one of the four connection points 42 of a foot member, which is disposed above a surface of a unit 30 so that an abutment surface of the foot member opposes a surface of the unit 30. As the foot member is moved towards the surface of the unit 30 (i.e. in a downward direction in the figures), a conical point 35 of fixed locating pin 34 will move into an attachment point 302 of unit 30 so that the conical point 35 extends into the bore of the attachment point 302. The conical point 35 acts as a guide to assist in locating the foot member correctly relative to the surface of the unit 30 (for example, if the position of the foot member relative to the surface of the unit 30 is such that the fixed locating pin 34 is slightly off-centre relative to an attachment point 302 into which the fixed locating pin 34 is to be inserted). FIG. 3c illustrates the foot member located in abutment with a surface of the unit 30, with the conical point 35 of fixed locating pin 34 extending into an attachment point 302 of the unit 30.

Once the foot member is positioned above the attachment points 302 of the unit 30, the motor 44 is operated to cause rotation of threaded rod 36. The rotation of the threaded rod 36 is such that it extends downwardly from the abutment surface of the foot member toward an attachment point 302 of unit 30 and, because the foot member is correctly located relative to the surface of unit 30 by way of the fixed locating pin 34, threaded rod 36 engages with attachment point 302 to secure the foot member to the unit 30. The threaded rod 36 is shown to be fully engaged with an attachment point 302 of unit 30 in FIG. 3d. Once the threaded rod 36 is fully engaged with the attachment point 302, operation of the motor 44 is stopped. When the threaded rod 36 is fully engaged with the attachment point 302, a connection between the foot member and unit comprises a structural connection between the foot member and the unit.

In an optional arrangement, the operation of the motor may be stopped responsive to an output signal received from a feedback mechanism. The output signal indicative of full engagement of the threaded rod 36 and attachment point 32. The feedback mechanism may comprise, for example, a contact switch or distance sensor.

FIGS. 4a to 4d illustrate a foot member 16 of the apparatus according to one or more embodiments of the present invention in a position for coupling to a unit 30 for a modular structure. FIG. 4a shows the foot member 16 and unit in a top plan view, FIG. 4b shows them in an end view, FIG. 4c shows them in a side view, and FIG. 4d shows them in a perspective top plan view. The relative positions of the foot member 16 and unit 30 illustrated in FIGS. 4a to 4d are equivalent to those illustrated in FIG. 3c. Thus, the abutment surface of foot member 16 abuts a surface of the unit 30 and each of the fixed locating pins 34 of each of the four connection points 42 are located to extend into four corresponding attachment points 300. In the arrangement illustrated, the motor 44 has not yet operated to move threaded rods 36 of the connection points 42 into engagement with the attachment points 300. That is, the threaded rods 36 are still in a retracted state and the foot member 16 is not coupled to the unit 30.

FIGS. 5a to 5d illustrate a foot member 16 of the apparatus according to one or more embodiments of the present invention in a position in which the foot member is coupled to a unit for a modular structure. FIG. 5a shows the foot member 16 and unit in a top plan view, FIG. 5b shows them in an end view, FIG. 5c shows them in a side view, and FIG. 5d shows them in a perspective top plan view. The relative positions of the foot member 16 and unit 30 illustrated in FIGS. 5a to 5d are equivalent to those illustrated in FIG. 3d. Thus, the abutment surface of foot member 16 abuts a surface of the unit 30 and each of the fixed locating pins 34 of each of the four connection points 42 are located to extend into four corresponding attachment points 300. In the arrangement illustrated, the motor 44 has operated to move threaded rods 36 of the connection points 42 into engagement with the attachment points 300. That is, the threaded rods 36 are in an extended state and the foot member 16 is coupled to the unit 30.

FIG. 6 is a series of illustrative schematic side views of an apparatus according to one or more embodiments of the present invention in various positions relative to a modular structure 48. FIG. 6 illustrates an example of movement of the apparatus relative to a modular structure whilst carrying a unit 32. The unit 32 carried by the apparatus 10 is to be added to the modular structure 48.

First schematic drawing 50 shows an apparatus 10 according to one or more embodiments of the present invention located upon a modular structure 48. The modular structure 48 comprises a plurality of units 30, 30'.

Apparatus 10 is carrying a unit 32 that has been collected from a supply area and is to be moved to a position in the modular structure 48, at which position the unit 32 is to be fixed to the modular structure 48.

In the series of drawings (i.e. 50 to 76), the unit 32 to be fixed to the modular structure 48 is to be moved to a position at the right-hand end of the modular structure 48 in the illustrated example.

Locomotion of the apparatus 10 relative to the modular structure 48, placement of the unit 32 relative to the modular structure 48, addition of the unit 32 to the modular structure 48, and return of the apparatus 10 to a start point are illustrated by way of drawing 50, and further drawings 52 to 76, which illustrate a series of stages in the above-indicated activities.

In drawing 50, the unit 32 is held by apparatus 10 by way of being coupled to third foot member 16c. The apparatus 10 is coupled to a unit 30 of the modular structure 48 by second foot member 16b. In this illustrative example, second foot member 16b is the "leading" foot member and first foot member 16a is "trailing" foot member in drawing 50. The apparatus 10 is illustrated in a position within its motion where it is oriented such that the chassis thereof is angled relative to a surface of the modular structure 48 upon which the apparatus 10 is located. As can be seen, the first foot member 16a is in a raised position where it is not in contact with the surface of the modular structure 48 upon which the apparatus 10 is located. To transition to the next stage in the movement- and-placement sequence (i.e. that illustrated in drawing 52), the chassis of apparatus 10 rotates about second foot member 16b about an axis denoted by line z-z in drawing 50.

In the stage of the movement-and-placement sequence illustrated in drawing 52, the chassis of the apparatus 10 is angled relative to a surface of the modular structure 48 upon which the apparatus 10 is located. Apparatus 10 is still coupled to a unit 30 of the modular structure 48 by second foot member 16b. However, first foot member 16a is now the "leading" foot member and second foot member 16b is "trailing" foot member in drawing 52. The first foot member 16a is in a raised position where it is not in contact with the surface of the modular structure 48 upon which the apparatus 10 is located. To transition to the next stage in the movement-and-placement sequence (i.e. that illustrated in drawing 54), the chassis of apparatus 10 rotates about second foot member 16b about an axis perpendicular to that denoted by line z-z of drawing 50. The direction of rotation is denoted by arrow R2 in drawing 52.

Rotation of the chassis of the apparatus 10 in this manner about second foot member 16b serves to lower the first foot member 16a toward another unit 30' of the modular structure 48 (i.e. to a position as illustrated in drawing 54).

In drawing 54, apparatus 10 is located such that both the first and second foot members 16a, 16b are coupled to the modular structure 48. The chassis of the apparatus 10 is parallel to the surface of the modular structure 48 upon which the apparatus 10 is located. To transition to the next stage in the movement-and-placement sequence (i.e. that illustrated in drawing 56), the chassis of apparatus 10 rotates about first foot member 16a about an axis perpendicular to that denoted by line z-z of drawing 50. The direction of rotation is denoted by arrow R in drawing 54.

Rotation of the chassis of the apparatus 10 in this manner about first foot member 16a serves to raise the second foot member 16b from the unit of the modular structure 48 to which it is attached (i.e. to a position as illustrated in drawing 56).

In drawing 56, apparatus 10 is coupled to unit 30' of the modular structure 48 by first foot member 16a. The apparatus 10 is illustrated in a position within its motion where it is oriented such that the chassis thereof is angled relative to a surface of the modular structure 48 upon which the apparatus 10 is located. As can be seen, the second foot member 16b is in a raised position where it is not in contact with the surface of the modular structure 48 upon which the apparatus 10 is located. To transition to the next stage in the movement-and-placement sequence (i.e. that illustrated in drawing 58), the chassis of apparatus 10 rotates about first foot member 16a about an axis denoted by line z-z in drawing 56.

In the stage of the movement-and-placement sequence illustrated in drawing 58, the chassis of the apparatus 10 is angled relative to a surface of the modular structure 48 upon which the apparatus 10 is located. Apparatus 10 is still coupled to a unit 30' of the modular structure 48 by first foot member 16a. First foot member 16a is the "trailing" foot member and second foot member 16b is "leading" foot member in drawing 58. The second foot member 16b is in a raised position. To transition to the next stage in the niovement-and-placement sequence (i.e. that illustrated in drawing 60), the chassis of apparatus 10 rotates about first foot member 16a about an axis perpendicular to that denoted by line z-z of drawing 56. The direction of rotation is denoted by arrow R2 in drawing 58.

In the stage of the movement-and-placement sequence illustrated in drawing 60, the apparatus 10 has no further unit to which it can attach itself (at the right-hand end of the modular structure 48). hi the stage of the movement-and-placement sequence illustrated in drawing 60 (and also those stages illustrated in drawings 62 to 70) the apparatus 10 is coupled to the modular structure 48 solely by first foot member 16a.

In the illustrated example, the right-hand end of the structure corresponds to the position where the unit 32 to be added to the modular structure 48 is to be positioned. Therefore, from the stage of the movement-and-placement sequence illustrated in drawing 60, the apparatus 10 is operative to lower the unit 32 to be added to the modular structure 48 into position in the modular structure 48. To achieve this, translational element of third foot member 16c is operative to lower the unit 32 from the position shown in drawing 60 to that shown in drawing 62 (i.e. in the direction denoted by arrow Tl in drawing 60).

When unit 32 is located in a correct position relative to the modular structure 48, it can be secured to the modular structure 48.

Following securing of unit 32 to the modular structure 32, third foot member 16c is operative to disengage from unit 32 (drawing 62) and retract to a stowed position relative to the chassis of the apparatus 10 (drawing 66). Retraction of the third foot member 16c to the stowed position is achieved by raising the third foot member 16c to the position shown in drawing 66 (i.e. in the direction denoted by arrow Tl in drawing 64).

The apparatus 10 can now return to the supply area, either to retrieve a further unit for addition to the modular structure 48, or to cease activity because the modular structure 48 is complete.

To return to the supply area from the position shown in drawing 66, the apparatus 10 first transitions from the stage illustrated in drawing 66 to that illustrated in drawing 68. This is achieved by rotating the chassis of apparatus 10 about first foot member 16a in a direction denoted by arrow R2 in drawing 66.

In the stage of a return sequence illustrated in drawing 68, the chassis of the apparatus 10 is angled relative to a surface of the modular structure 48 upon which the apparatus 10 is located. Apparatus 10 is coupled to a unit of the modular structure 48 by first foot member 16a. First foot member 16a is the "leading" foot member and second foot member 16b is "trailing" foot member in drawing 68. The second foot member 16b is in a raised position. To transition to the next stage in the return sequence (i.e. that illustrated in drawing 70), the chassis of apparatus 10 rotates about first foot member 16a about an axis denoted by line z-z in drawing 68.

In the stage of the return sequence illustrated in drawing 70, the chassis of the apparatus 10 is angled relative to a surface of the modular structure 48 upon which the apparatus 10 is located. Apparatus 10 is coupled to a unit of the modular structure 48 by first foot member 16a. First foot member 16a is now the "trailing" foot member and second foot member 16b is "leading" foot member in drawing 70. The second foot member 16b is in a raised position. To transition to the next stage in the return sequence (i.e. that illustrated in drawing 72), the chassis of apparatus 10 rotates about first foot member 16a about an axis perpendicular to that denoted by line z-z of drawing 68. The direction of rotation is denoted by arrow R2 in drawing 70.

Rotation of the chassis of the apparatus 10 in this manner about first foot member 16a serves to lower the second foot member 16b toward a unit of the modular structure 48 (i.e. to a position as illustrated in drawing 72).

In drawing 72, apparatus 10 is located such that both the first and second foot members 16a,

16b are coupled to the modular structure 48. The chassis of the apparatus 10 is parallel to the surface of the modular structure 48 upon which the apparatus 10 is located. To transition to the next stage in the return sequence (i.e. that illustrated in drawing 74), the chassis of apparatus 10 rotates about second foot member 16b about an axis perpendicular to that denoted by line z-z of drawing 68. The direction of rotation is denoted by arrow R2 in drawing 72.

Rotation of the chassis of the apparatus 10 in this manner about second foot member 16b serves to raise the first foot member 16a from the unit of the modular structure 48 to which it is attached (i.e. to a position as illustrated in drawing 74).

In drawing 74, apparatus 10 is coupled to a unit of the modular structure 48 by second foot member 16b. The apparatus 10 is illustrated in a position within its motion where it is oriented such that the chassis thereof is angled relative to a surface of the modular structure 48 upon which the apparatus 10 is located. As can be seen, the first foot member 16a is in a raised position where it is not in contact with the surface of the modular structure 48 upon which the apparatus 10 is located. To transition to the next stage in the return sequence (i.e. that illustrated in drawing 76), the chassis of apparatus 10 rotates about second foot member 16b about an axis denoted by line z-z in drawing 74.

Stages of the return sequence illustrated in drawings 70 to 76 may be repeated until the apparatus reaches the supply area.

FIG 7 is an illustrative perspective view of part of the apparatus 10 and two units 30, 32. The figure illustrates how two units 30, 32 may be fixed together. Unit 32 can be coupled to unit 30 using fixing plates 78, 80.

In the illustrated example, a fixing plate 78 is prefixed to one edge of unit 30 and a fixing plate 80 is prefixed to one edge of unit 32. The fixing plates 78, 80 are attached to attachment points such that when attached with bolts 82 the surface of the fixing plate 78 is flush with a surface of the unit 32, and the fixing plate 80 is flush with an opposite surface of the unit 30.

In the illustrated example shown in FIG. 7, the unit 32 is attached to third foot member 16c.

The apparatus is attached to unit 30 via second foot member 16b. The apparatus 10 is operative to position the unit 32 such that holes in the fixing plate 78 of unit 30 are aligned above attachment points of unit 32 and such that holes in the fixing plate 80 of unit 32 are aligned above attachment points of unit 30. Securing elements, such as, for example, bolts 82 or screws, may then be inserted through the holes in fixing plates 78, 80 into respective attachment points of units 30, 32 thereby fixing unit 32 to unit 30.

FIG. 8a and 8b illustrate an apparatus according to one or more embodiments of the present invention in an optional arrangement during a locating step of locating a unit against another unit.

In the illustrated example, the apparatus 10 includes an arm 84 mounted upon the chassis of the apparatus 10. Towards (or at) an end of the ann 84 remote from the end at which the arm 84 is mounted to the chassis, there is located a securing element attachment device 86.

Units 30, 32 are connected together by plate 88 in the illustrated example (see Fig. 8b). The plate 88 is pre-attached to one unit and therefore only requires securing elements 90 to be attached (through the plate 88) to the attachment points of the other unit. The arm 84 has the ability to move laterally along rail 92 and vertically through linear motor 94 (which serves to move the arm relative to a mounting point). Through combination of movement of the arm laterally along rail 92 and vertically relative to the chassis, it is possible to access all possible attachment points on the exterior faces of the units 30, 32.

In an optional arrangement, the securing element attachment device may be disposed on a wrist-jointed arm assembly instead of a rail and arm assembly.

Instructions provided to the apparatus 10 (i.e. to control operation thereof) may be created by creating a 3D model (using a processor) of a modular structure to be constructed. An attachment point indexing module implementable by the processor operates to assign a unique attachment point index to each attachment point for each unit in the modular structure. Therefore, edges of each unit in the modular structure are defined by attachment point indices assigned to the attachment points of that unit. That is, the edges of each unit are defined by data representing the attachment point indices. Navigation of the apparatus 10 relative to the modular structure is guided by data representing the attachment point indices and placement of the foot members on units of the modular structure is also guided by instructions indicating to which attachment points (and which unit) the foot members should attach. Likewise, the attachment of the attachment member of the third foot member to attachment points of a unit to be added to a structure (or removed from a structure) is guided by data representing the attachment point indices of the relevant attachment points.

A design module (implementable by the processor) may allow for unit-connection possibilities to be simulated. The design module may compose virtual modular structures by arranging the units into pre-defined assembly patterns based upon user input to a design system. For example, a user may require a truss spanning a certain distance that is capable of carrying a specific load. The design module allows a modular structure design to be created and the attachment point indexing module creates attachment point indices for attachment points of each unit in the structure. The attachment point indices data is used to generate a set of instructions to be provided for controlling the apparatus 10 to build the designed modular structure. The design modular optionally may implement integrated structural simulation and optimisation functions, which may improve the efficiency of a modular structure arrangement.

The attachment points of the units dictate the form and degrees of freedom of the apparatus

10; how the apparatus 10 physically traverses the structure and computes its movements to do so; how it manipulates units into position; and how it orients itself relative to the structure. The attachment points establish a basic unit by which the apparatus 10 can navigate a path over a modular structure and by which it can position units in the modular structure (or remove units therefrom).

FIG. 9a illustrates a perspective view of an apparatus 100 for interaction with a modular structure according to another one or more embodiments of the present invention. Like apparatus according to one or more embodiments described above in relation to FIGS. 1 to 8, the underlying principle relates to relatively small robots, which may be able to work individually or in teams, being used to assemble modular structures larger than the robot itself. This may overcome the limitations on scale of the buildable object of "fixed working zone" traditional robot systems.

When applied to traditional masonry or bricklaying, there is the possibility of a robot or team of robots to work alongside human workers on the same construction site, without requiring a safety isolation areas or additional infrastructure to the support the robot system.

The apparatus 100 differs from the apparatus 10 (described above in relation to FIGS. 1 to 8) in at least two areas: a foot member of apparatus 100 is configured to interact with and manipulate traditional masonry bricks rather than custom bricks with threaded connection points; and the apparatus 100 employs dynamic stabilisation, which may remove the need for screwed or locked attachment of the feet members to units, instead relying on gravity alone.

The apparatus 100 comprises a chassis 102, which comprises an elongate element. The apparatus 100 further comprises a first foot member 106a and a second foot member 106b. First and second foot members 106a, 106b each comprise an attachment member that is configured to engage with an attachment point of a unit. The attachment members of the foot members will be described in more detail later.

The first and second foot members 106a, 106b are coupled to the chassis 102 by respective first and second coupling elements 108a, 108b operative to permit relative movement between the first foot member 106a and the chassis 102, and the second foot member 106b and the chassis 102. The first and second foot members 106a, 106b are connected to respective first and second coupling elements 108a, 108b by respective first and second legs 109a, 109b. The first and second coupling elements 108a, 108b comprise bearings that allow linear movement of the first and second coupling elements 108a, 108b along the chassis 102. This enables linear movement of the first and second foot members 106a, 106b relative to chassis 102 (i.e. by sliding movement of first and second coupling elements 108a, 108b along the chassis 102). The chassis 102 can be free-moving, so can be moved independently, e.g. while the first and second foot members 106a, 106b are stationary.

The apparatus 100 also comprises a third foot member 106c that is coupled to the chassis 102 by a third coupling element 108c. Like the first and second coupling elements 108a, 108b, the third coupling element 108c is operative to permit relative movement between the third foot member 106c and the chassis 102. The third foot member 108c is connected to the third coupling element 108c by third leg 109c. The third coupling element 108c comprises bearings that allow linear movement of the third coupling element 108c along the chassis 102. This enables linear movement of third foot member 106c relative to chassis 102 (i.e. by sliding movement of third coupling element 108c along the chassis 102).

The third foot member 106c comprises an attachment member operative to releasably couple the third foot member 106c to a unit for a modular structure via cooperative engagement of the attachment member with an attachment point of the unit. The attachment member of the third foot member 106c will be described in more detail later.

The first and second foot members 106a, 106b are operative to engage with attachment points of units of a modular structure and can permit locomotion , or traversal, of the apparatus 100 relative to the modular structure (e.g. over, across, and/or along the modular structure). The third foot member 106c is operative to attach to a unit that is to be added to, or removed from, a modular structure. For example, the apparatus 100 may be located at a unit supply area where a unit for addition to a modular structure is collected by the apparatus 100 by engagement of the attachment member of the third foot member 106c with an attachment point of the unit to be added to the modular structure. Upon collection of the unit, the apparatus 100 can mount the modular structure and traverse the modular structure to a position adjacent where the unit is to be placed. The third foot member 106c is used to manipulate the unit to a correct orientation and is also used to place the unit into position in the modular structure. This process will be further described later in relation to Fig. 12.

In FIG. 9b, the apparatus 100 is shown upon part of a modular structure 400. In the illustrated example, the first foot member 106a is engaged with a first unit 402 of the modular structure 400 and the second foot member 106b is engaged with a second unit 404 of the modular structure 400. The third foot member 106c is coupled to a third unit 406. The third unit 406 is a unit to be located in the modular structure 400. The third foot member 106c allows third unit 406 to be manoeuvred into a position in the modular structure where the third unit 406 can be placed against another part, or other parts, of the modular structure 400.

The units 402, 404 may form part of a modular structure that will be assembled by apparatus 100. In FIG. 9b, the units comprise UK-standard three-hole bricks. However, the apparatus may be adapted to build a modular structure using other brick-types by using differently configured foot members. The three-hole bricks illustrated in FIG. 9b comprise three holes 408a, 408b, 408c, which extend through the bricks from a first surface (top surface in figure) to a second surface (bottom surface - not visible in figure). These holes comprise attachment points via which the first, second and foot members can engage with the bricks. In the example illustrated in FIG. 9b, a central hole of the three holes, i.e. hole 408b, comprises an attachment point of each unit (i.e. brick) with which the foot members engage.

When the units are arranged to form a modular structure, such as the modular structure 400 illustrated in FIG. 9b, the holes 408b provide equally spaced attachment points that form a continuous path of attachment points for the apparatus 100. Each attachment point may be uniquely indexed so that the apparatus 100 may ascertain its position when located on a modular structure. The apparatus 100 can ascertain where it is on the modular structure 400 by determining with which attachment points it is engaged.

It is in this manner that the apparatus 100 can attach itself to units of a modular structure and also pick-up and hold a unit for placement in the modular structure.

First, second and third foot members 106a, 106b, 106c each include an attachment member to permit engagement of the foot members with an attachment point of a unit. FIG. 10 is a detailed perspective view of an underside of first and second foot members 106a, 106b of the apparatus 100 illustrating respective attachment members 133a, 133b. FIG. 11 is a detailed perspective view of an underside of third foot member 106c illustrating attachment member 133c.

The attachment members 133a, 133b (see FIG. 10) comprise an abutment plate 140, which defines a planar surface for placement against a surface of a unit for a modular structure. The attachment members 133a, 133b further comprise an engagement protrusion 134 that is configured to be insertable into an attachment point of a unit of a modular structure, (e.g. the hole 408b of the unit of the modular structure 400 illustrated in FIG. 9b).

The engagement protrusion 134 is configured so that it cannot pivot out of hole 408b (if an apparatus counterbalance system were to fail). The engagement protrusion 134 is intended to extend into the hole and, if the apparatus 100 were to begin to tip, the engagement protrusion 134 would press against wall of the hole 408b to prevent toppling of the apparatus 100). The protrusion may have a pointed end to correct for error up to the size of the hole radius - the pointed end will "guide" the foot into the hole.

Attachment member 133c of third foot member 106c (see Fig. 11) is similar to the attachment members 133a, 133b of first and second foot member 106a, 106b, in that it also comprises an abutment plate 140 and an engagement protrusion 134. In addition, the attachment member 133c of third foot member 106c further comprises grippers 142, 144 configured to grip a unit carried by the third foot member. In relation to the three-hole brick type of unit, the grippers 142, 144 are configured to be insertable into attachment points of a unit of a modular structure. That is, for the attachment member 133c illustrated in FIG. 11 , the grippers are configured to be insertable into the holes 408a and 408c of the unit of the modular structure 400 illustrated in FIG. 9b. The grippers 142, 144 are controllable to increase/decrease a spacing therebetween so that a gripping force applied by the grippers can be increased/decreased to grip/release a unit. Although FIGS. 10 and 11 illustrate foot members configured for engagement with three-hole brick type units, for a different unit type (e.g. a different brick type), the foot members can be exchanged with different foot member configurations that are specific to the other unit types. For example, a ten-hole engineering brick, a "London Stock" brick, a brick with an indented top, or a brick with a flat top. While the gripper configuration illustrated in FIG. 11 uses two protrusions in addition to an engagement protrusion, other bricks could have different gripper designs. Optionally, another gripper configuration would be one in which bricks are gripped from the outside width-ways.

FIG. 12 is a series of illustrative schematic side views of the apparatus 100 illustrated in FIGS. 9a and 9b in various positions relative to a modular structure. FIG. 12 illustrates an example of movement of the apparatus 100 relative to a modular structure whilst carrying a unit 406. The unit 406 carried by the apparatus 100 is to be added to the modular structure 400.

The apparatus 100 described above in relation to FIGS. 9 to 1 1 employs a counterbalancing technique to traverse a modular structure 400 while carrying a unit 406. The counterbalancing technique makes use of the weight of a unit (e.g. a brick) carried by the third foot member 106c or by the weight of the third foot member 106c (when no unit is being carried), to counterbalance the weight of one the first or second foot members as that foot member is lifted, moved and placed down to take a step. The counterbalance is moved to the opposite end of the chassis 102 and the process is repeated for the other of the first or second foot members. As the foot member is moved, the counterbalance can be moved in the opposite direction with appropriate acceleration such as to neutralise the jerk on the apparatus 100 as it balances on the other foot member. For example, if the combined weight of a unit and the third foot member weighs three times that of a foot member to be moved, then it is moved with 1/3 of the acceleration.

For placing the unit in a placement position in the modular structure 400, the chassis 102 may be moved to extend forward of the front-most foot member to allow the unit to cantilever out, balanced by the weight of the rear-most foot member. Depending on the weight of the unit and positions of surrounding units already in the modular structure 400, the rear-most foot member may be in mid-air, or if allowed, may be placed on a unit already on the structure. This may allow the overall centre of mass to be between the two grounded legs as the brick is placed to give more stability.

Also, if an existing structure allows, the first and second foot members may both be "grounded" and straddle a placement position of the unit that is carried by the apparatus 100, and the unit can be lowered to the placement position (e.g. such as in a conventional gantry).

Both first and second foot members can move in a vertical axis perpendicular to the chassis 102, which may be achieved using a threaded screw drive. By lowering both at the same time, this has the effect of lowering the main beam and thus the unit with it. For the robot to step up while walking the structure, one foot member is raised first allowing it to clear the step and become grounded. Then both first and second foot members can raise the beam together to the new height. Then the first or second foot member is stepped onto the new level. Stepping down is achieved in reverse. The proportions of the robot allow clearance for the brick to move and clear the foot members in both cases.

First schematic drawing 200 shows an apparatus 100 according to one or more embodiments of the present invention located upon a modular structure 400. The modular structure 400 comprises a plurality of units 300, 302, 304 and 306.

Apparatus 100 is carrying a unit 320 that has been collected from a supply area and is to be moved to a position in the modular structure 400, at which position the unit 320 is to be located in a placement position of the modular structure 400.

In the series of drawings (i.e. 200 to 226), the unit 320 to be fixed to the modular structure 400 is to be moved to a position at the right-hand end of the modular structure 400 in the illustrated example.

Locomotion of the apparatus 100 relative to the modular structure 400, placement of the unit 320 relative to the modular structure 400, addition of the unit 320 to the modular structure 400, and return of the apparatus 100 towards a start point are illustrated by way of drawing 200, and further drawings 202 to 226, which illustrate a series of stages in the above-indicated activities.

In drawing 200, the unit 320 is held by apparatus 100 by way of being engaged with third foot member 106c. The apparatus 100 is engaged with units 302 and 304 of the modular structure 400 by first and second foot members 106a, 106b respectively. In this illustrative example, second foot member 106b is the "leading" foot member and first foot member 106a is "trailing" foot member in drawing 200. To transition to the next stage in the movement-and-placement sequence (i.e. that illustrated in drawing 202), the second foot member 106b is raised in direction denoted by arrow VI in drawing 200.

In the stage of the movement-and-placement sequence illustrated in drawing 202, the second foot member 106b is raised above a top surface of the modular structure 400 (i.e. above unit 304), and the apparatus 100 is supported on the modular structure 400 by first foot member 106a only. The third foot member 106c, which is carrying unit 320, is positioned so as to counterbalance the raised second foot member 106b. To transition to the next stage in the movement-and-placement sequence (i.e. that illustrated in drawing 204), the second foot member 106b is moved along a length of the chassis in a direction denoted by arrow HI in drawing 202 so as to be positioned above unit 306 of the modular structure 400. To maintain balancing of the apparatus 100 about a "standing-leg" thereof, i.e. the first foot member 106a, the third foot member 106c is moved along a length of the chassis in a direction denoted by arrow H2 in drawing 202, which is an opposite direction to the direction of movement of the second foot member 106b. In drawing 204, second foot member 106b is located such that it is above unit 306 of the modular structure 400. To transition to the next stage in the movement-and-placement sequence (i.e. that illustrated in drawing 206), the second foot member 106b is lowered in a direction denoted by arrow V2 in drawing 204.

Lowering of second foot member 106b in this manner serves to engage the second foot member 106b with unit 306 of the modular structure 400 (i.e. to a position as illustrated in drawing 206).

In drawing 206, apparatus 100 is engaged with units 302 and 306 by first and second foot members 106a, 106b respectively. To transition to the next stage in the movement-and-placement sequence (i.e. that illustrated in drawing 208), the third foot member 106c is moved along a length of the chassis in a direction denoted by arrow H3 in drawing 206.

In the stage of the movement-and-placement sequence illustrated in drawing 208, the third foot member 106c is located in a position in advance of the "leading" foot, i.e. second foot member 106b. To transition to the next stage in the movement-and-placement sequence (i.e. that illustrated in drawing 210), the first foot member 106a is raised in a direction denoted by arrow V3 in drawing 208. hi the stage of the movement-and-placement sequence illustrated in drawing 210, the first foot member 106a is raised above a top surface of the modular structure 400 (i.e. above unit 302), and the apparatus 100 is supported on the modular structure 400 by second foot member 106b only. The third foot member 106c, which is carrying unit 320, is positioned so as to counterbalance the raised first foot member 106a. To transition to the next stage in the movement-and-placement sequence (i.e. that illustrated in drawing 212), the first foot member 106a is moved along a length of the chassis in a direction denoted by arrow H4 in drawing 210 so as to be positioned above unit 304 of the modular structure 400. To maintain balancing of the apparatus 100 about a "standing-leg" thereof, i.e. the second foot member 106b, the third foot member 106c is moved along a length of the chassis in a direction denoted by arrow H5 in drawing 210, which is an opposite direction to the direction of movement of the first foot member 106a.

hi drawing 212, first foot member 106a is located such that it is above unit 304 of the modular structure 400. To transition to the next stage in the movement-and-placement sequence (i.e. that illustrated in drawing 214), the first foot member 106a is lowered in a direction denoted by arrow V4 in drawing 212.

Lowering of first foot member 106a in this manner serves to engage the first foot member 106a with unit 304 of the modular structure 400 (i.e. to a position as illustrated in drawing 214).

hi drawing 214, apparatus 100 is engaged with units 304 and 306 by first and second foot members 106a, 106b respectively. To transition to the next stage in the movement-and-placement sequence (i.e. that illustrated in drawing 216), the third foot member 106c is moved along a length of the chassis in a direction denoted by arrow H6 in drawing 214 to the position illustrated in drawing 214. In the illustrated example, the right-hand end of the structure corresponds to the position where the unit 320 to be added to the modular structure 400 is to be positioned. Therefore, from the stage of the movement-and-placement sequence illustrated in drawing 214, the apparatus 100 is operative to lower itself, to lower the unit 320 to be added to the modular structure 400 into position in the modular structure 400. To achieve this, the chassis is lowered relative to first and second foot member 106a, 106b by effecting vertical sliding movement of the first and second foot members 106a, 106b relative to the chassis (through control of the respective coupling elements). Optionally, this is effected by a screw drive in each coupling element. In lowering the chassis in this manner, unit 320 is lowered from the position shown in drawing 214 to that shown in drawing 216 (i.e. in the direction denoted by arrow V5 in drawing 214).

Following placement of unit 320 in the modular structure 400, third foot member 106c is operative to disengage from unit 320 and be retracted from contact with the unit 320 by raising the chassis relative to the top surface of the modular structure 400 (drawing 218). Raising of the chassis is achieved by raising the chassis relative to the first and second foot members 106a, 106b, which is effected by vertical sliding movement of the first and second foot members 106a, 106b relative to the chassis (through control of the respective coupling elements). Thus, the third foot member 106c is effectively "raised" to the position shown in drawing 218 (i.e. in the direction denoted by arrow V6 in drawing 216).

The apparatus 100 can now return to the supply area, either to retrieve a further unit for addition to the modular structure 400, or may cease activity because the modular structure 400 is complete.

To return to the supply area from the position shown in drawing 218, the apparatus 10 first transitions from the stage illustrated in drawing 218 to that illustrated in drawing 220. This is achieved by sliding the chassis horizontally (in a direction denoted by arrow H7 in drawing 218) relative to the "standing legs", i.e. first and second foot members 106a, 106b, whose positions are fixed through engagement with units 304, 306 of the modular structure 400. This is effected by control of respective coupling elements of the first and second foot members 106a, 106b. Additionally, third foot members 106c is moved relative to chassis in a horizontal direction denoted by arrow H8 in drawing 218 so that, when chassis slides in direction H7, third foot member 106c slides in an opposite direction H8 so as to maintain a position above unit 320. This is to ensure that the apparatus 100 is counterbalanced in readiness for raising of first foot member 106a (see drawing 222).

To transition to the next stage in the sequence as illustrated in drawing 222 (i.e. now a "return" sequence), the first foot member 106a is raised in a direction denoted by arrow V7 in drawing 220.

In the stage of the return sequence illustrated in drawing 222, the first foot member 106a is raised above a top surface of the modular structure 400 (i.e. above unit 304), and the apparatus 100 is supported on the modular structure 400 by second foot member 106b only. The third foot member 106c, which is carrying unit 320, is positioned so as to counterbalance the raised first foot member 106a. To transition to the next stage in the return sequence (i.e. that illustrated in drawing 224), the first foot member 106a is moved along a length of the chassis in a direction denoted by arrow H9 in drawing 222 so as to be positioned above unit 302 of the modular structure 400. To maintain balancing of the apparatus 100 about a "standing-leg" thereof, i.e. the second foot member 106b, the third foot member 106c is moved along a length of the chassis in a direction denoted by arrow H10 in drawing 210, which is an opposite direction to the direction of movement of the first foot member 106a.

In drawing 224, first foot member 106a is located such that it is above unit 302 of the modular structure 400. To transition to the next stage in the return sequence (i.e. that illustrated in drawing 226), the first foot member 106a is lowered in a direction denoted by arrow V8 in drawing 224.

Lowering of first foot member 106a in this manner serves to engage the first foot member 106a with unit 302 of the modular structure 400 (i.e. to a position as illustrated in drawing 226).

In drawing 226, apparatus 100 is engaged with units 304 and 306 by first and second foot members 106a, 106b respectively.

The return sequence can continue by alternately moving the first and second foot members 106a, 106b in the above-described manner until the apparatus reaches the supply area.

In an optional arrangement of the one or embodiments described in relation to Figs. 9 to 12, one foot member may rotate about a vertical axis. This can allow the apparatus to change direction, i.e. so as to traverse a right-angle corner between transverse sections of a modular structure. However, this limits the range of movement of the apparatus to perpendicular sections only, because a second foot member cannot rotate. However, in another optional arrangement, both foot members may rotate about a vertical axis, which would allow the apparatus to traverse modular structures having fully freeform, or curved, sections. Optionally, the third foot member may be rotatable about a vertical axis to allow a unit carried by the third foot member to be laid in-line, perpendicular or at an angle.

The overall weight distribution of the apparatus is arranged so as to be balanced in the vertical plane front-to-back. For example, the chassis is placed centrally, with the legs of the first and second foot members offset to one side to allow a unit to pass under the chassis unimpeded. Likewise, actuators (e.g. motors) for effecting actuation of coupling elements may be offset on an opposite side of the chassis to balance the weight of the legs' vertical profiles.

In one or more optional arrangements, the apparatus may comprise sensors, which may be employed, for example, to assist with self-balancing, to measure unit (e.g. brick) brick position as it is being placed to ensure alignment and levelling, etc.. Additionally, external sensors or scanners may be situated around a build area to monitor the build product (e.g. whether units are where they should be relative to the ideal 3D model) or to check for interference/disturbance or track robots' positions. This could be a 3D LIDAR scanner or depth sensing camera on a tripod, drone, or tower set up so it can survey the site and robots as the build progresses. This could be monitored onsite or remotely. In one or more optional arrangements, the apparatus may comprise mortar and/or adhesive dispensing and/or applicator elements. In one example, a mortar/adhesive applicator may be integrated into the third foot member, for example, a nozzle may protrude through or behind the unit and kinematic control of the third foot member may be employed to apply mortar/adhesive to the surfaces of units already laid, before the new unit is placed on top. In another example, a mortar/adhesive applicator may integrated into the first and/or second foot member. A nozzle may protrude on the front edge of the abutment plate. A unit may be manipulated by the third foot member so it is passed against the nozzle, coating the underside and vertical face of the brick with mortar. The brick is then placed onto the existing structure. Both examples may require a set-up whereby smaller loads of mortar are transferred from a main supply area to the apparatus robot for each unit-placement trip. In one or more optional arrangements, the chassis of the apparatus may be used to store additional units e.g. in a rack contained inside the chassis, which may be hollow to accommodate such additional units. For each unit stored, this may save the apparatus a trip back to a unit supply area. If the chassis could store four, or five, additional units, for example, this could have an effect on assembly time. That is, if, for example, a daily target of units to be added to the modular structure was 500 units, if the number of trips to a unit supply area could be reduced from 500 trips (i.e. where only one unit is carried per trip) to 100 trips (where five units are carried per trip) this may reduce assembly time, or mean that fewer apparatus per modular structure would be required.

The above one or more described embodiments may be combined in an optional arrangement. Insofar as the disclosure described above is implementable, at least in part, using a machine readable instruction-controlled programmable processing device such as a general purpose processor or special-purposes processor, digital signal processor, microprocessor, or other processing device, data processing apparatus or computer system it will be appreciated that a computer program for configuring a programmable device, apparatus or system to implement the foregoing described methods, apparatus and system is envisaged as an aspect of the present disclosure and claimed subject matter. The computer program may be embodied as any suitable type of code, such as source code, object code, compiled code, interpreted code, executable code, static code, and or dynamic code, for example. The instructions may be implemented using any suitable high-level, low-level, object- oriented, visual, compiled and/or interpreted programming language, such as C, C++, Java, BASIC, Perl, Matlab, Pascal, Visual BASIC, JAVA, ActiveX, assembly language, machine code, and so forth. The term "computer" in its most general sense may encompass programmable devices and data processing apparatus and computer systems in whatever format they may arise, for example, desktop personal computer, laptop personal computer, tablet, smart phone or other computing device.

The computer program may be stored on a computer readable storage medium in machine readable form, for example the computer readable storage medium may comprise memory, removable or non-removable media, erasable or non-erasable media, writeable or re-writeable media, digital or analog media, hard disk, floppy disk, Compact Disk Read Only Memory (CD-ROM), Compact Disk Recordable (CD-R), Compact Disk Rewriteable (CD-RW), optical disk, magnetic media, magneto-optical media, removable memory cards or disks, various types of Digital Versatile Disk (DVD) subscriber identity module, tape, cassette solid-state memory. The computer program may be supplied from a remote source and embodied in a communications medium such as an electronic signal, radio frequency carrier wave or optical carrier waves. Such carrier media are also envisaged as aspects of the present disclosure.

As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having" or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, "or" refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

In addition, use of the "a" or "an" are employed to describe elements and components of the disclosure. This is done merely for convenience and to give a general sense of the disclosure. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.

Various modifications may be made within the scope of the disclosure.

The scope of the present disclosure includes any novel feature or combination of features disclosed therein either explicitly or implicitly or any generalisation thereof irrespective of whether or not it relates to the claimed subject matter or mitigates against any or all of the issues addressed by the present disclosure. The applicant hereby gives notice that new claims may be formulated to such features during prosecution of this application or of any such further application derived therefrom. In particular, with reference to the appended claims, features from dependent claims may be combined with those of the independent claims and features from respective independent claims may be combined in any appropriate manner and not merely in specific combinations enumerated in the claims.