Technical Field

[0001] Embodiments of the present disclosure relate to robots, interchangeable robot combinations, of base robot and module robot, which are suitable for climbing slopes, performing on-the-spot turns, automatically configuring the base robot upon successful licence verification and diagnostic test, implementing emergency stop at either or both base robot and module robot.

Background

[0002] High costs of single-function robots, combined with the fact that robots usually serve just a single function, means that adopting robots in commercial settings (all aspects from sweeping, scrubbing, sanitizing, vacuuming to buffing, surveillance, delivery, hospitality, service, etc.) is an expensive exercise in the real world, despite the obvious productivity and efficiency advantages.

[0003] Cleaning in narrow spaces is a real-world navigational problem for many robots due to spatial requirements to make directional changes such as a U-turn. Although some current robots are able to turn 360° on the spot (either via differential centre wheel or 4 mecanum wheel system), these are still few and far between.

[0004] Existing robots capable of climbing slopes use either rear-wheel drive or traction wheel assembly with steering, but none of them enables both slope climbing and full rotation/turning of the robots on the spot.

[0005] Existing robot or machine that has a modular design only has safety features, e.g. emergency stop (or E-Stop), on one side of the robot (normally the side that holds the navigation devices). The reachability or accessibility of a sole E-Stop feature may not be sufficient to allow immediate and easy access during emergency especially if the robot has large dimensions.

[0006] Existing robots with ostensible ‘modular’ designs still need to be reconfigured in the factory to make a switch between different modular functions. Hence, there is no true plug- and-play modular robot in existing robot solutions.

[0007] To address at least some of the above issues, a robot which comprises a front base, a back module coupled to the front base, and a spring loaded centre wheel may be utilised. However, combining these features results in other issues. Figure 1 shows a schematic arrangement of a robot which comprises a base robot (front base), a module robot (back module), and a spring loaded centre wheel. In this arrangement, the spring loaded centre driving wheel would tend to push up the rear portion of the base robot. This causes the base robot to be tilted up from a horizontal direction when module robot is not docked to the base robot. This results in a difficulty in handling the base robot since it is not level horizontally and a further difficulty in docking the module robot to the base robot.

Summary

[0008] A first aspect provides a robot combination which comprises: a base robot which includes a base robot body, driving wheel assemblies which are configured to drive the base robot at least up a slope, a passive wheel assembly, and a side wing structure, wherein each driving wheel assembly includes a driving wheel and a wheel biasing mechanism which is configured to provide a force normal to the sloped surface to enable the driving wheel maintain traction with the slope, wherein the side wing structure is configured to counterbalance a moment produced by the wheel biasing mechanism and a weight of the base robot body to prevent tilting of the base robot body; and a module robot removably docked to the base robot.

[0009] According to an embodiment of the first aspect, each driving wheel is arranged at a substantially mid-point position along a length which is defined by at least the base robot body and the side wing structure.

[0010] According to an embodiment of the first aspect, the side wing structure includes side wings which extend from the base robot body in an opposed relation, wherein the module robot is accommodate in a space between the side wings, and wherein each side wing includes an alignment assembly arranged in mutual alignment with a complementary alignment assembly of the module robot.

[0011] According to an embodiment of the first aspect, either one of the alignment assembly and the complementary alignment assembly includes a vertical positioning element having a vertically-oriented roller and a horizontal positioning element having a horizontally-oriented roller, wherein the vertically-oriented roller and the horizontal-oriented roller are removably engaged with a roller-receiving support of the other one of the alignment assembly and the complementary alignment assembly.

[0012] According to an embodiment of the first aspect, the base robot is configured to be interchangeably docked with a second module robot, and the module robot and the second module robot are configured to perform different functions.

[0013] According to an embodiment of the first aspect, the base robot includes a base robot memory and a base robot computing unit communicably coupled thereto, the module robot includes a module robot memory and a module robot computing unit communicably coupled thereto, the base robot computing unit is configured to execute instructions stored in the base robot memory to: after the module robot is docked to the base robot, establish data communication between the base robot computing unit and the module robot computing unit; automatically verify, by the base robot computing unit, a licence of the module robot; upon successful verification of the licence, automatically perform, by the module robot computing unit, a diagnostic test on the module robot; upon successful performance of the diagnostic test, provide, by the base robot computing unit, operating instructions to the module robot computing unit.

[0014] According to an embodiment of the first aspect, the base computing unit is further configured to execute instructions stored in the base memory to: upon unsuccessful verification of the licence, provide, by the base computing unit, a notification of unsuccessful verification of the licence; or upon unsuccessful performance of the diagnostic test, provide, by the base computing unit, a notification of diagnostic error.

[0015] According to an embodiment of the first aspect, the base robot computing unit is further configured to: reconfigure, by the base computing unit, parameters at the base robot according to a function type of the module robot.

[0016] According to an embodiment of the first aspect, the emergency stop line includes: a base robot electrical circuitry arranged at the base robot and having, electrically coupled in series, an emergency stop line power source, a plurality of base robot stop buttons, a base robot controllable switch, a first base-module interface, a base robot load driver or relay which is configured to control a base robot load; and a module robot electrical circuitry having, electrically coupled in series, a second basemodule interface, a plurality of module robot stop buttons, a module robot load driver or relay which is configured to control a module robot load, wherein the base robot includes a base robot bumper, wherein at least one of the base robot stop buttons is configured to be activated by an impact on the base robot bumper, wherein the module robot includes a module robot bumper, wherein at least one of the module robot stop buttons is configured to be activated by an impact on the module robot bumper, wherein the base robot controllable switch is configured to electrically couple, by the removable docking of the module robot to the base robot, the base robot electrical circuitry to the module robot electrical circuitry to provide the emergency stop line in a closed-circuit state, wherein the emergency stop line is configured to change from the closed-circuit state to an open-circuit state by activation of any one of the base robot stop buttons or any one of the module robot stop buttons, wherein the closed-circuit state of the emergency stop line is configured to cause the base robot load driver or relay to allow power delivery from a base robot load power source to the base robot load, and cause the module robot load driver or relay to allow power delivery from a module robot load power source to the module robot load, wherein the open-circuit state of the emergency stop line is configured to cause the base robot load driver or relay to terminate power delivery from the base robot load power source to the base robot load, and cause the module robot load driver or relay to terminate power delivery from the module robot load power source to the module robot load.

[0017] According to an embodiment of the first aspect, the base robot computing unit is communicably coupled to the base robot stop buttons and configured to identify at least one of the base robot stop buttons being activated, wherein the module robot computing unit is communicably coupled to the module-side stop buttons and configured to identify at least one of the module robot stop buttons being activated.

[0018] A second aspect provides a method which comprises: removably docking a module robot to a base robot to provide a robot combination, wherein the base robot includes a body, driving wheel assemblies attached to the body, and a passive wheel assembly attached to the body, and a side wing structure, wherein each driving wheel assembly includes a driving wheel and a wheel biasing mechanism, driving the robot combination up a slope and performing an on-the-spot turn, including: providing, by the wheel biasing mechanism, a force normal to the slope thereby maintaining traction of the driving wheel with the slope; counterbalancing, by the side wing structure, a moment produced by the wheel biasing mechanism and a weight of the base robot body thereby preventing tilting of the base robot.

[0019] In an embodiment of the second aspect, each driving wheel is arranged at a substantially mid-point position along a length which is defined by the base robot body and the side wing structure.

[0020] In an embodiment of the second aspect, the side wing structure includes side wings which extend from the base robot body in an opposed relation to provide a space for accommodating a module robot, wherein each side wing includes an alignment assembly, wherein the module robot includes a complementary alignment assembly, wherein removably docking a module robot to a base robot to provide a robot combination includes: mutually aligning the alignment assembly with the complementary alignment assembly.

[0021] In an embodiment of the second aspect, either one of the alignment assembly and the complementary alignment assembly includes a vertical positioning element having a vertically- oriented roller and a horizontal positioning element having a horizontally-oriented roller, wherein the vertically-oriented roller and the horizontal-oriented roller are removably engaged with a roller-receiving support of the other one of the alignment assembly and the complementary alignment assembly.

[0022] In an embodiment of the second aspect, the method further comprises: interchangeably docking a second module robot to the base robot, wherein the module robot and the second module robot are configured to perform different functions.

[0023] In an embodiment of the second aspect, the base robot includes a base robot memory and a base robot computing unit communicably coupled thereto, wherein the module robot includes a module robot memory and a module robot computing unit communicably coupled thereto, wherein the method further comprises: after the module robot is docked to the base robot, establishing data communication between the base robot and the module robot computing unit; automatically verifying, by the base robot computing unit, a licence of the module robot; upon successful verification of the licence, automatically performing, by the module robot computing unit, a diagnostic test on the module robot; upon successful performance of the diagnostic test, providing, by the base robot computing unit, operating instructions to the module robot computing unit.

[0024] In an embodiment of the second aspect, the method further comprises: upon unsuccessful verification of the licence, providing, by the base computing unit, a notification of unsuccessful verification of the licence; or upon unsuccessful performance of the diagnostic test, providing, by the base computing unit, a notification of diagnostic error.

[0025] In an embodiment of the second aspect, the method further comprises: reconfiguring the base robot according to a function type of the module robot.

[0026] In an embodiment of the second aspect, the robot combination includes an emergency stop line which includes: a base robot electrical circuitry arranged at the base robot and having, electrically coupled in series, an emergency stop line power source, a plurality of base robot stop buttons, a base robot controllable switch, a base robot load driver or relay which is configured to control a base robot load, a module robot electrical circuitry arranged at the module robot and having, electrically coupled in series, a plurality of module robot stop buttons, a module robot load driver or relay which is configured to control a module robot load, wherein the base robot includes a base robot bumper, wherein at least one of the base robot stop buttons is configured to be activated by an impact on the base robot bumper, wherein the module robot includes a module robot bumper, wherein at least one of the module stop buttons is configured to be activated by an impact on the module robot bumper; wherein removably docking the module robot to the base robot to provide a robot combination includes: in response to removable docking of the module robot to the base robot, electrically coupling, through the base robot controllable switch, the base robot electrical circuitry to the module electrical circuitry, in series, to provide the emergency stop line in a closed-circuit state, allowing, by the base robot load driver or relay, power delivery from a base robot load power source to the base robot load when the emergency stop line is in closed- circuit state, allowing, by the module robot load driver or relay, power delivery from a module robot load power source to the module robot load when the emergency stop line is in the closed-circuit state, the method further comprising: activating any one of the base robot stop buttons or any one of the module robot stop buttons, thereby changing the emergency stop line from the closed-circuit state to the open-circuit state, thereby causing the base robot load driver or relay to terminate power delivery from the base robot load power source to the base robot load, and simultaneously causing the module robot load driver or relay to terminate power delivery from the module robot power source to the module robot load.

[0027] In an embodiment of the second aspect, the base robot computing unit is communicably coupled to the base robot stop buttons, wherein the module robot computing unit is communicably coupled to the module robot computing unit, wherein the method further comprises: identifying, by the base robot computing unit, at least one of the base robot stop buttons being activated; and identifying, by the module robot computing unit, at least one of the module robot stop buttons being activated.

[0028] A third aspect provides a base robot which comprises: a base robot body; driving wheel assemblies which are configured to drive the base robot up a slope; a passive wheel assembly; and a side wing structure, wherein each driving wheel assembly includes a driving wheel and a wheel biasing mechanism which is configured to provide a force normal to the slope to enable the driving wheel maintain traction with the slope, wherein the side wing structure is configured to counterbalance a moment produced by the wheel biasing mechanism and a weight of the base robot body to prevent tilting of the base robot.

[0029] In an embodiment of the third aspect, each driving wheel is arranged at a substantially mid-point position along a length which is defined by the base robot body and the side wing structure.

[0030] In an embodiment of the third aspect, the side wing structure includes side wings which extend from the base robot body in an opposed relation to provide a space for accommodating a module robot, and wherein each side wing includes an alignment assembly configured to mutually align with a complementary alignment assembly of the module robot.

[0031] In an embodiment of the third aspect, the alignment assembly includes a vertical positioning element having a vertically-oriented roller and a horizontal positioning element having a horizontally-oriented roller, wherein the vertically-oriented roller and the horizontal- oriented roller are configured to complement a roller-receiving support of the complementary alignment assembly of the module robot.

[0032] In an embodiment of the third aspect, the base robot further comprises: an emergency stop line which includes a base robot electrical circuitry arranged at the base robot and having, electrically coupled in series, an emergency stop line power source, a plurality of base robot stop buttons, a base robot controllable switch, a first base-module interface, a base robot load driver or relay which is configured to control a base robot load, wherein the base robot includes a base robot bumper, wherein at least one of the base robot stop buttons is configured to be activated by an impact on the base robot bumper, wherein the emergency stop line is configured to change from closed-circuit state to open-circuit state by activation of any one of the base robot stop buttons, wherein the closed-circuit state of the emergency stop line is configured to cause the base robot load driver or relay to allow power delivery from a base robot load power source to the base robot load, wherein the open-circuit state of the emergency stop line is configured to cause the base robot load driver or relay to terminate power delivery from the base robot load power source to the base robot load. Brief Description of Drawings

[0033] Figure 1 shows a schematic arrangement of a robot combination which comprises a base robot, a module robot, and a spring loaded centre driving wheel.

[0034] Figures 2A, 2B, and 2C show perspective views of a robot combination, a standalone base robot, and a standalone module robot, respectively.

[0035] Figures 2D, 2E, and 2F show top views of a robot combination, a standalone base robot, and a standalone module robot, of Figures 2A, 2B, and 2C respectively.

[0036] Figure 3A shows a wheel biasing mechanism employed in a centre driving wheel.

[0037] Figure 3B shows a predetermined vertical distance which the wheel biasing mechanism of Figure 3A is configured to urge or move the driving wheel towards the ground or work surface.

[0038] Figure 3C shows a driving wheel assembly comprising the wheel biasing mechanism of Figure 3A and a driving wheel.

[0039] Figure 4 shows various views (perspective view, top view, internal frame) of a side wing structure provided at a base robot.

[0040] Figure 5A shows vertical positioning features and horizontal positioning features.

[0041] Figure 5B shows positioning features which are complementary to Figure 5A.

[0042] Figure 5C shows partial cross-sectional rear and side views of a robot combination, particularly the features of Figures 5A and 5B in docked arrangement.

[0043] Figure 6 shows a schematic representation of communicable coupling of the base robot and the module robot when docked to each other.

[0044] Figure 7A shows a flowchart of a plug and play procedure.

[0045] Figures 7B and 7C show possible variations to the plug and play procedure of Figure 7A.

[0046] Figure 8A shows a circuit diagram for implementing E-Stop and Safety Bumper.

[0047] Figure 8B shows a circuit diagram for implementing E-Stop and Safety Bumper, using CAN protocol and wire connection.

[0048] Figure 8C shows a circuit diagram for implementing E-Stop and Safety Bumper, using CAN protocol and wireless connection.

Detailed Description

[0049] In the following description, numerous specific details are set forth in order to provide a thorough understanding of various illustrative embodiments of the invention. It will be understood, however, to one skilled in the art, that embodiments of the invention may be practiced without some or all of these specific details. In other instances, well known process operations have not been described in detail in order not to unnecessarily obscure pertinent aspects of embodiments being described. [0050] Embodiments described in the context of one of the methods, apparatus, or systems are analogously applicable to the other methods, apparatus, or systems. Similarly, embodiments described in the context of a method are analogously applicable to an apparatus or system, and vice versa.

[0051] Features that are described in the context of an embodiment may correspondingly be applicable to the same or similar features in the other embodiments. Features that are described in the context of an embodiment may correspondingly be applicable to the other embodiments, even if not explicitly described in these other embodiments. Furthermore, additions and/or combinations and/or alternatives as described for a feature in the context of an embodiment may correspondingly be applicable to the same or similar feature in the other embodiments.

[0052] In the drawings, like reference numerals refer to same or similar functionalities or features throughout the several views. The particular arrangements shown in the drawings should not be viewed as limiting. It should be understood that other embodiments can include more or less of each element shown in a given figure. Some of the illustrated elements can be combined or omitted.

[0053] In the context of various embodiments, including examples and claims, the articles “a”, “an” and “the” as used with regard to a feature or element include a reference to one or more of the features or elements. The terms “comprising,” “including,” “having”, and their variations are intended to be open-ended and mean that there may be additional features or elements other than the listed ones. The term “and/or” includes any and all combinations of one or more of the associated listed items. Identifiers such as “first”, “second” and “third” are used merely as labels, and are not intended to impose numerical requirements on their objects, nor construed in a manner imposing any relative position or time sequence between limitations. The term “coupled” may refer to physically coupling, electrically coupling, operably coupled and/or communicably coupling, unless otherwise specified. The term “coupled” when applied to two objects may refer to the two objects being coupled directly or indirectly through a third object and may refer to the two objects being fixedly or movably coupled. The term “dock” may refer to physically coupling to provide an operational combination. The term “docked” when applied to two objects may refer to the two objects being physically coupled directly or indirectly through a third object. Accordingly, the term “undock” may refer to physically decoupling of the combination. The term “control” may refer to activate, deactivate, and/or operate. The term “control” when applied to two objects may refer to direct control or indirect control through a third object. Modularity, Centre Driving Wheel with Wheel Biasing Mechanism & Side Wing Structure [0054] In embodiments, a robot combination comprises a base robot and at least one module robot which is removably docked thereto. The base robot and the module robot may be docked in a horizontal or lateral direction. Upon docking, the horizontal or lateral dimensions of the robot combination may remain substantially the same or extended; the vertical dimensions of the robot combination may remain substantially the same or extended. Optionally, additional or subseguent module robot(s) may be docked to the module robot which is docked to the base robot to provide an extended robot combination with further extended horizontal length or width, or vertical height, or both.

[0055] The base robot is configured to be interchangeably docked with a second module robot, and possibly other module robots (third, fourth, etc, module robots). It is to be appreciated that the base robot may provide navigation functions while the module robots may respectively provide different functions, e.g. vacuuming, mopping, polishing, etc, but other functions may be envisaged for the base robot and the module robot. Interchangeable docking therefore allows changes in robot combinations to perform different functions or operations.

[0056] Some example arrangements of a robot combination include a front-back arrangement in which the base robot is arranged in front and at least one module robot is arranged behind the base robot, and a back-front arrangement in which the module robot is arranged in front and the base robot is arranged behind the module robot. In this context, the terms “front” and “back” refer to relative positions along a direction of motion during robot operation. Accordingly, wheels of the base robot and any wheels of the module robot would be in moving contact with the ground or work surface during robot operation.

[0057] In some embodiments, the robot configuration is designed in a way that allows the module robot to have a lot of internal space to work with. This allows for numerous possibilities and functions to explore. The components of the base robot may be compacted into the front half of the base robot, leaving the rest of the space for the module robot. Important and expensive components may be arranged at the base robot to minimize the price of the module robot to make it more economical to purchase. As the module robot may be located at the back of the base robot with its own independent passive wheels, this would not restrict subsequent modules to be within the same footprint/size/shape. The subsequent module(s) may be longer, wider, and/or taller than the module robot which is docked to the base robot.

[0058] Figures 2A and 2D, respectively, show perspective and top views of a robot combination 10 according to some embodiments. Figures 2B and 2E, respectively, show perspective and top views of a standalone base robot 20 according to some embodiments. Figures 2C and 2F, respectively, show perspective and top views of a standalone module robot 30 according to some embodiments. [0059] The base robot 20 comprises a base robot body 21 , two or more driving wheel assemblies 22 which are coupled to the base robot body 21 and configured to drive the base robot body 21 along a ground or work surface, e.g. up or down a slope, a non-slope or flat surface. Each driving wheel assembly 22 includes a driving wheel 221 with a wheel biasing mechanism 222 (wheel extension mechanism) which is configured to provide a substantially constant normal force to urge the driving wheel 221 towards the ground or work surface to enable the driving wheel 221 to maintain sufficient traction to drive the base robot 20 or robot combination 10 up a slope. The driving wheel 221 may be arranged at a substantially midpoint along a length of the base robot 20, e.g. centre or near centre position along the length (see approximate locations shown by dash-line arrows 221 in Figure 2E). The driving wheel 221 may therefore be referred to as centre driving wheel. The length of the base robot 20 may be taken along a direction of motion of the base robot 20. The length of the base robot 20 may refer to the largest or non-largest dimension. Optionally, the driving wheel 221 may be arranged at a substantially mid-point of the length of a robot combination 10 comprising the base robot 20 and module robot 30.

[0060] The driving wheels 221 are arranged proximate to opposed sides of the base robot body 21 , e.g. non-mid-point position along a breadth of the base robot 20 but the driving wheels 221 may be alternatively arranged at other positions (not shown), e.g. substantially mid-point positions along the breadth of the base robot 20. The breadth of the base robot 20 may be taken along a direction orthogonal to the length of the base robot 20.

[0061] One or more passive wheel assemblies may be coupled to a front end or near front end of the base robot body 20 (see approximate location shown by dash-line arrows 241 in Figure 2E).

[0062] The wheel biasing mechanism 222 may be operably coupled to the driving wheel 221 to bias the driving wheel 221 towards a desired direction, e.g. vertically towards the ground or work surface. The wheel biasing mechanism 222 may be provided as a spring mechanism, e.g. gas spring mechanism, coil spring, hydraulic mechanism, or other equivalent.

[0063] Figure 3A shows a gas spring mechanism 223. Figure 3B shows a predetermined vertical distance 224 which the gas spring mechanism 223 is configured to urge or move the driving wheel 221 towards the ground or work surface. The amount of extension may be calculated based on a worst-case position to facilitate a 7-degree or more slope climb. Figure 3C shows a driving wheel assembly 22 comprising the gas spring mechanism 223 of Figure 3A and a driving wheel 221 operably coupled thereto.

[0064] With the provision of wheel biasing mechanism 222 to a centre driving wheel 221 as described in the present disclosure, a robot combination 10 according to the present disclosure is able to turn/rotate 360 degrees on the spot and climb slopes. This solves a design challenge because a conventional robot that can climb slopes has front or rear driving wheel, which also means that it will not be able to turn on the spot. On the other hand, a conventional robot having a centre driving wheel faces issues when its front passive wheel climbs up a slope while its centre driving wheel would be lifted off the ground. This results in the driving wheel having no traction with the ground or work surface, thus is unable to drive the conventional robot forward.

[0065] The base robot 20 includes a side wing structure 23. The side wing structure 23 may comprise two or more side wings 231 extending from the base robot body 21 , e.g. near bottom of the base robot body 21. Dimensions of each side wing 231 may be smaller or substantially smaller than the base robot body 21 , however they may alternatively be larger than the base robot body 21. The side wings 231 may be arranged in an opposed relation to define a space therebetween for accommodating or receiving a module robot 30 or at least part thereof.

[0066] Other equivalent side wing structures may be envisaged. For example, a side wing structure may include only one wing. However, it is to be appreciated that the side wing structure 23 would address the above-described tilting up issue of the base robot 20. Firstly, the side wing structure 23 would provide a counterweight which is configured to balance out a moment produced by the wheel biasing mechanism 222. This would prevent the base robot 20 from being front-heavy, and help the base robot 20 to be level horizontally even without a presence of a docked module robot, i.e. when the base robot 20 is standalone. Secondly, the side wing structure 23 may house all the perception sensors to be included in the base robot 20. In order for the robot to have 360-degree visibility, some sensors such as 2D Lidar and 3D Camera may be arranged very close to the base robot’s rear portion (which is on the module robot side). The presence of the side wing structure 23 allows arrangement of all sensors on the base robot 20 (instead of module robot). This allows expensive sensors to be arranged at the base robot 20 as it may be desirable for the module robot 30 to be as cheap as possible to be economically sensible. Thirdly, the side wing structure 23 may further act as an alignment or lead-in feature to guide or help a user dock the module robot 30 to the base robot 20.

[0067] Figure 4 shows various views (perspective view, top view, internal frame) of a side wing structure 23 provided at a base robot 20 and having two side wings 231 .

[0068] The base robot 20 and the module robot 30 include mutually complementary alignment or lead-in assemblies to facilitate or guide mutual alignment in one or more directions during docking of a module robot 30 to a base robot 20 and/or undocking. The mutually complementary alignment assemblies may be male and female types. For example, the module robot may include protrusions, rollers, movable or rotatable knobs, etc., while the base robot may include receiving recesses, chamfered structures, grooves, etc., or vice versa.

[0069] Figure 5A shows an alignment assembly 50 includes movable positioning features, e.g. vertical positioning features having vertically-oriented rollers 51 and horizontal positioning features having horizontally-oriented rollers 52. While Figure 5A illustrates multiple features and rollers, it is to be appreciated that they may be substituted by one feature and one roller. [0070] Figure 5B shows a complementary alignment assembly 55 includes non-movable positioning feature, e.g. a roller-receiving support having a C-shape profile frame 55.

[0071] Figure 5C shows a partial rear cross-sectional view and a partial side view of a robot combination 10, particularly the mutually aligned alignment elements 50, 55 of Figures 5A and 5B. In particular, opposed members of the C-shape profile frame 55 are in contact with the vertically-oriented rollers 51 while an intermediate member, which is between the opposed members of the C-shape profile frame 55, is in supporting contact with the horizontally- oriented rollers 52.

[0072] In Figures 2A, 2B, 2D, 2E and 4, the alignment assembly 50 of Figure 5A is provided at the base robot 20 while the complementary assembly 55 of Figure 5B is provided at the module robot 30. It is to be appreciated that in other examples (not shown), the alignment assembly 50 of Figure 5A may be provided at the module robot 30 while the complementary alignment assembly 55 of Figure 5B may be provided at the base robot 20.

[0073] A combination of centre driving wheel assembly 22, with wheel biasing mechanism 222, and side wing structure 23 provided at the base robot body 20 is particularly advantageous. The centre wheel biasing mechanism 222 solves 360 degrees turning-on-the- spot and climbing issues concurrently, hence allowing for more terrain coverage by the robot combination 10, increased mobility and deployability. Climbing a slope having a gradient of up to 7 degrees or more can be achieved. The side wing structure 23 provides alignment elements 50, 55 for easy assembly or docking by an end-user. The side wing structure 23 provides additional balancing controlled-weight, and may provide a housing for navigational sensors.

[0074] The module robot 30 comprises a module robot body 31 and a plurality of passive wheel assemblies 341 (see Figure 2C and some approximate locations shown by dash-line arrows 341 in Figure 2E) which are coupled to the module robot body 31 and configured to facilitate robot motion along the work surface.

Plug and Play Procedure

[0075] In embodiments, one or more module robots 30 are interchangeably and/or removably docked to a base robot 20. Upon docking, verification of licence of the module robot 30, diagnostic test of the module robot 30, and/or software reconfiguration of the base robot 20 may be performed automatically without requiring user intervention.

[0076] The base robot 20 may further include a base robot memory and a base robot computing unit which is communicably coupled to the base robot memory and configured to execute instructions stored in the base robot memory. The module robot 30 may further include a module robot memory and a module robot computing unit which is communicably coupled to the module robot memory and configured to execute instructions stored in the module robot memory.

[0077] Figure 6 shows a schematic representation of communication coupling of the base robot and the module robot when they are docked to each other. In particular, the base robot computing unit is communicably coupled to the module robot computing unit. The base robot memory may store various configurations for different module robots. Once the base robot detects the module robot, base robot computing unit is configured to send computerexecutable instructions to the module robot computing unit, and set the mode of the base robot specific to the module robot so the module robot computing unit is enabled to return with information/data, operate load of the module robot, or actuate the actuator. The module robot computing unit and module robot memory are configured to receive computer-executable instructions from the base robot computing unit. The module robot computing unit may be communicably coupled to sensor units, interchangeable apparatus, and actuators. The base robot and the module robot may comprise further components, e.g. base robot bumper, module robot bumper, which are described later or not described or shown in the present disclosure. For example, the base robot may include a first base-module interface and the module robot may include a second base-module interface, wherein the interfaces are communicably coupled when the module robot is docked to the base robot. References to computing unit or microcontroller unit may refer to circuitry or device capable of sequentially and automatically carrying out a sequence of arithmetic or logical operations; recording, storing, and/or transferring digital data. Examples include processor, single board computer, programmable logic controller and/or any other device capable of executing or otherwise operating computer-executable instructions, such as program code, software modules, and/or functional processes.

[0078] Data flow between the base robot and the module robot may take place via a standard communication protocol over a physical data link, e.g. USB, CANBUS, UDP/TCP, etc. Alternatively, data flow may take place via wireless communication protocol.

[0079] Figure 7A shows a flowchart of a plug and play procedure which is described as follows. Upon docking the module robot to the base robot, initial data communication is established between the base robot and the module robot. The base robot, e.g. base robot computing unit, receives identification of the module robot type, e.g. the firmware of the Microcontroller Unit (MCU) in the module robot may publish the identity of its module type to the base robot. The base robot, e.g. base robot computing unit, automatically verifies the licence of the module, e.g. the module robot’s license number embedded within its MCU firmware may be received and verified by the base robot. The verification may include checking, by the base robot computing unit, from a licence database which is communicably coupled thereto, whether the user has paid for the usage of the module robot before the module robot is authorized to be operated. If verification of licence fails, e.g. licence is invalid, unpaid or expired, a notification of unsuccessful verification of licence may be provided, e.g. an alert may be raised and provided to the user for intervention. However, if verification of licence is successful, e.g. licence is valid, paid or unexpired, the module robot, e.g. module robot computing unit, may automatically perform a set of self-diagnostic tests on itself. If any diagnostic test fails, a notification of diagnostic error may be provided, e.g. an alert may be raised and provided to the user for intervention via robot’s user interface and/or remote fleet management interface that can be accessed via the internet. If diagnostic test(s) are successfully performed, i.e. no error, data communication is successfully established between the base robot and the module robot for module robot operation. The base robot, e.g. base robot computing unit, may proceed to provide operating instructions to the module robot, e.g. module robot computing unit, to operate the module robot.

[0080] Some examples of diagnostic tests include running components of the module robot in a limited capacity and checking the internal sensors to determine if they are working as expected, e.g. run the module robot’s motor that turns a roller brush and check if the encoder provides the feedback that the motor is turning, sending a heartbeat signal to the controller and checking if it returns the signal, etc. All diagnostic test results may be logged into a database communicably coupled to the base robot computing unit.

[0081] In Figure 7A, prior to verification of the licence, software parameters at the robot base may be configured. In particular, based on the docked module type detected by the base robot, the software parameters at the base robot may be reconfigured to match the purpose or function type of the module robot. An instance of this would be the internal state machine determining which actions are allowed or restricted based on the current module type. For example, if a scrubber model is detected, it may allow or configure the base robot to be in cleaning state which will cause the base robot to move in snake pattern that will cover the whole area and turn more slowly than other cleaning robot since it is water based and needs to collect water. If a surveillance model is detected, it may allow or configure the base robot to be in surveillance mode which will cause the base robot to travel point to point like a patrol and capture the video of surrounding environment on the run.

[0082] Figures 7B and 7C show possible variations to the plug and play procedure of Figure 7A.

[0083] In Figure 7B, the plug and play procedure differs from Figure 7A in that both identification of the module robot type and reconfiguration of software parameters take place after successful module licence verification. [0084] In Figure 7C, the plug and play procedure differs from Figure 7A in that identification of the module robot type takes place before verification of module licence, and reconfiguration of software parameters takes place after successful module licence verification.

[0085] The above-described plug and play procedure is particularly advantageous at least in that a user may interchangeably and/or removably dock module robots 30 to the base robot 20 and operate the robot combination 10 without requiring factory intervention or reconfiguration, thus providing a true plug-and-play experience which is supremely user- friendly, cost efficient and multi-purpose. In particular, the module robot 30 may automatically or self-identify its module type to the base robot 20 upon docking; the base robot 20 may automatically or self-verify the licence of the detected module robot 30 against a licence database, authorise use of the module robot 30 upon successful verification, perform selfdiagnostic tests on the module robot 30, configuring software parameters of the base robot 20 upon successful self-diagnosis. If the verification of licence fails or if the self-diagnosis fails, an alert may be raised to the user and/or the base robot 20 would not or would not be able to operate the module robot 30. Accordingly, user intervention is not required to detect module type, verify licence, perform diagnostic tests, or configure software parameters of the base robot 20 in order to be able to work with the module robot 30.

Emergency Stop (E-Stop) and Safety Bumper

[0086] In embodiments, each of the base robot and the module robot may include one or more emergency stop (E-Stop) features. When the module robot is docked to the base robot, any one of the E-Stop features may be activated to halt operation of both the base robot and the module robot.

[0087] In embodiments, each of the base robot and the module robot may further, optionally, include one or more safety bumper (Safety Bumper) features. When the module robot is docked to the base robot, any one of the Safety Bumper features may be activated to halt operation of both the base robot and the module robot. Safety Bumper feature may be activated by an impact on a predetermined portion of the base module robot, e.g. base robot bumper, or module robot, e.g. module robot bumper. Such impact may be generated by collision between the bumper of the base or module robot with another object.

[0088] The E-Stop features and Safety Bumper features may communicate with the base robot and/or module robot using wired or wireless connection and/or any suitable communication protocol.

[0089] In embodiments, regardless of implementation, the E-stop features and Safety Bumper features may be collectively or alternatively referred to as stop buttons. An objective of the E- stop features and Safety Bumper features is to provide emergency stop capabilities at both base robot and module robot to stop operation of the combination robot whether emergency stop instruction goes through wired or wireless connection or using any other suitable communication protocol.

[0090] Figure 8A shows a circuit diagram for implementing stop buttons (E-Stop and Safety Bumper features) which may be described as follows. The base robot 20 includes a base robot electrical circuitry 25 which includes an emergency stop line power or voltage source (E-stop Line Power), a plurality of base robot stop buttons (E-Stop Button, Bumper), a base robot controllable switch (Controllable Switch), a first base-module interface (Base Module Interface), and one or more base robot load drivers or relays (Driver/Relay). A base robot load driver may be configured to control a base robot load (Motor). A base robot load relay may be configured to control a base robot driver which may in turn be configured to control a base robot load (Motor). Other examples of loads which are not shown may be envisaged, e.g. ultraviolet light, laser light, etc. The base robot motor loads (Motors) may be powered by one or more base robot motor power sources (Motor Power).

[0091] When the base robot 20 is standalone with no docked module robot, the base robot electrical circuitry 25 provides an emergency stop line or circuitry (E-Stop line or circuitry). In the base robot electrical circuitry 25, the emergency stop line power source, configured to provide power to an E-stop line or circuit, is electrically coupled in series to the base robot stop buttons, which include one or more base robot E-Stop features and one or more base robot Safety Bumpers features. In an example, three Safety Bumper features may be arranged in series to respectively control relays which are configured to open-circuit the base robot electrical circuitry 25 when any one of the Safety Bumper features is engaged or activated. The base robot stop buttons are electrically coupled in series to the base robot controllable switch which is configured to be selectively electrically coupled in series to the first basemodule interface or to the one or more base robot load drivers or relays. In other words, electrical coupling of the base robot controllable switch may be toggled, i.e. connect to the module robot load driver or relay via the first base-module interface, or connect to the base robot load (motor). In the latter case, the output of the base robot controllable switch may be electrically coupled in series to a base robot load relay (or driver or any activation device) for every load (motor). The base robot electrical circuitry 25 may be grounded (not shown).

[0092] When the base robot 20 is standalone with no docked module robot and the base robot electrical circuitry 25 is in closed-circuit state, a high voltage signal provided in the base robot electrical circuitry 25 causes the base robot load driver or relay to be activated or allow power delivery from the base robot power source to the base robot load. The base robot electrical circuitry 25 is configured to be changed from closed-circuit state to open-circuit state when any of the base robot stop buttons is engaged or activated. In the open-circuit state, a low voltage signal provided in the base robot electrical circuitry 25 causes the base robot driver or relay to deactivate or terminate power delivery from the base robot power source to the base robot load. For feedback purposes, each of the base robot stop buttons may be communicably coupled to the base robot computing unit which is configured to detect which one of the base robot stop buttons is engaged or activated.

[0093] The base robot controllable switch is configured to be electrically coupled to the one or more base robot loads (motors) when the base robot 20 is standalone. However, the base robot controllable switch is configured to be electrically coupled to the base module interface when the module robot 30 is removably docked to the base robot 20. In particular, the base robot controllable switch may be provided as a MOSFET, relay, opto switch, etc, which is configured to be operated by a suitable controller which will alternate or toggle the switch connection as described above.

[0094] The module robot 30 includes a module robot electrical circuitry 35 which includes a plurality of module robot stop buttons (E-Stop Buttons, Bumper), a second base-module interface (Base Module Interface), a terminal block (Terminal), and one or more module robot load drivers or relays (Driver/Relay). A module robot load driver may be configured to control a module robot load (Motor). A module robot load relay may be configured to control a module load driver which may in turn be configured to control a module robot load (Motor). Other examples of loads which are not shown may be envisaged, e.g. ultraviolet light, laser light, etc. The module robot motor loads (Motors) may be powered by one or more module robot motor power sources (Motor Power).

[0095] In the module robot electrical circuitry 35, the base-module interface is electrically coupled to the module robot stop buttons, which include module robot E-Stop feature and module robot Safety Bumpers features, in series. The output from the module robot stop buttons is electrically coupled to a relay (or driver or any activation device) for every load (motor). The output from the module robot stop buttons is also electrically coupled to the terminal block which is to provide a return signal, via the second base-module interface and the first base-module interface, to the base robot electrical circuity 25. The module robot electrical circuitry 35 may be grounded (not shown).

[0096] When the module robot 30 is docked to the base robot 20, the base robot electrical circuitry 25 and the module robot electrical circuitry 35 are electrically coupled to provide the emergency stop line or circuitry (E-stop line or circuitry) which is in closed-circuit state until any one of the base robot stop buttons or any one of the module robot stop buttons is activated, or the module robot 30 is unintentionally undocked from the base robot 20. The E-stop line or circuitry comprises the base robot electrical circuity 25 and the module robot electrical circuity 35 which are electrically coupled in series via the first and the second base-module interface. In particular, to enable this closed-circuit state in the emergency stop line, the base robot controllable switch is activated or toggled, by the docking, to electrically couple to the first base-module interface. In this closed-circuit state, a high voltage signal is provided in the base robot electrical circuitry 25 which causes the base robot load driver or relay to be activated or allow power delivery from the base robot power source to the base robot load; and at the same time causes the module robot load driver or relay to activate or allow power delivery from the module robot power source to the module robot load to enable normal operation of the base robot 20 and the module robot 30, respectively.

[0097] If any base robot or module robot stop button is activated, the emergency stop line will change to open-circuit state. When the emergency stop line is in the open-circuit state, a low voltage signal is provided in the base robot electrical circuitry 25 which causes the base robot driver or relay to deactivate or terminate power delivery from the base robot power source to the base robot load; and at the same time causes the module robot driver or relay to deactivate or terminate power delivery from the module robot power source to the module robot load, and hence the base robot 20 and the module robot 30 cannot perform normal operations.

[0098] For example, if any base robot stop button is activated, the base robot electrical circuitry 25 is changed to open-circuit state; this change of the base robot electrical circuitry 25 to open-circuit state simultaneously changes the emergency stop line to open-circuit state. For example, if any module robot stop button is activated, the module robot electrical circuitry 35 is changed to open-circuit state and returns a signal (no-power signal) via the second basemodule interface and the first base-module interface; this change of the module robot electrical circuitry 35 to open-circuit state simultaneously changes the emergency stop line to opencircuit state.

[0099] For feedback purposes, similar to the base robot, each of the module robot stop buttons may be communicably coupled to the module robot computing unit which is configured to detect which one of the module robot stop buttons is engaged or activated.

[00100] Ground reference for the base robot electrical circuitry 25 and the base robot electrical circuitry 35 may be shared between the base robot 20 and the module robot 30 by the base-module interfaces so the signal will work according to the function.

[00101] In case of intentional disconnection of the base robot 20 and the module robot 30, e.g. where none of the stop buttons is activated, the base robot controllable switch, e.g. MOSFET, relay, opto switch, etc, which is controlled by a suitable controller, will turn the switch so it will close the loop which enables the loads (motors) of the base robot 30 to operate as per normal.

[00102] Implementing this hardware connected system and simple power signal is to ensure the safety level of the E-Stop. Software implementation and/or wireless connection are possible but may make the feature less safe.

[00103] The E-Stop feature and, optionally, Safety Bumper feature, are particularly advantageous in that activation of any E-stop feature on either base robot 20 or module robot 30 can stop operation of both robots 20, 30. The base robot 20 can still operate on its own (navigation) when it is standalone, e.g. undocked or disconnected from the module robot 30. Bumper activation on either base robot 20 or module robot 30 will also stop the robot’s operation through hardware and not software. The system is able to detect which devices activate the whole stopping state, e.g. front bumper cuts the entire E-Stop line.

[00104] Variations to the above-described embodiments may be made, including but not limited to the following.

[00105] Instead of having E-Stop line using 12V line I other voltage line on the robot, communication line via USB, Ethernet, etc (wired) or Bluetooth, IR, etc (wireless) with any kind of communication protocol (lO-Link, EtherCAT, CANBus, TCP/IP, Modbus, etc) may alternatively or additionally be used to stop the moving robot in an emergency, but the latter approach may not fail-safe as complexity of protocol (mostly serial communication) is prone to have more error and slower instead of direct digital signal (High or Low) of the primitive voltage line (using 12V / other voltage line).

[00106] For example, instead of using E-Stop to disable all devices by cutting the line, another possible method is to use E-Stop that is connected to CANBus (famous protocol is CANOpen) node that monitors the E-Stop. If the E-Stop is being pressed, the CAN node will send disabled signal through the other CAN nodes that controls the Actuation Devices so it will stop the operation. The connection between the base robot and the module robot can be wired or wireless. Since CAN node can recognize the connected or disconnected state, there is no need for a relay to change the loop connection like the embodiment described in relation to Figure 8A.

[00107] Figure 8B shows a circuit diagram for implementing E-Stop and Safety Bumper, using CAN protocol and wire connection. Figure 8B differs from Figure 8A in that the base robot controllable switch is replaced by a base robot CAN/Eth controller while the output of module robot stop buttons is electrically coupled to the loads (motors) via a module robot CAN/Eth controller.

[00108] Figure 8C shows a circuit diagram for implementing E-Stop and Safety Bumper, using CAN protocol and wireless connection. Figure 8C differs from Figure 8B in that communication interface between the base robot and the module robot is a wireless connection.

[00109] A flow sequence of operating a robot combination may be provided as follows:

[00110] A module robot is removably docked to a base robot to provide a robot combination. The module robot, the base robot, and the robot combination may refer to any embodiment of the present disclosure. This removable docking may include mutually aligning an alignment assembly of the base robot with a complementary alignment assembly of the module robot. [00111] After the removable docking and before operating the robot combination, the robot combination may perform a plug and play procedure as described above to verify licence of the module robot and/or perform diagnostic tests on the module robot, reconfiguring the base robot according to a function type of the module robot, etc.

[00112] After successful verification of licence and diagnostic tests, the base robot, e.g. its software parameters, is reconfigured according to a function type of the module robot. During this reconfiguration, the controllable switch of the base robot electrical circuitry is toggled, i.e. switch from connecting to the load driver/relay of the base electrical circuitry to connecting to the first base module interface.

[00113] After the reconfiguration, the robot combination is operated, e.g. driven up a slope and perform an on-the-spot turn on the slope. The wheel biasing mechanism provides a force normal to the work surface thereby maintaining traction of the driving wheel with the slope. Operating the robot combination on a slope is optional as the robot combination may be operated on a non-slope surface.

[00114] While the robot combination is in the docked arrangement and no emergency stop button is activated, the emergency stop line, which comprises the base electrical circuitry and the module robot electrical circuitry in series, is in closed-circuit state in which the base load driver or relay allows power delivery from a base robot load power source to the base robot load and the module load driver or relay allows power delivery from a module robot load power source to the module robot load.

[00115] When any emergency stop button, whether on the base robot or module robot, is activated, e.g. by an impact on a bumper of the base robot or module robot, the emergency stop line is caused to change from closed-circuit state to open-circuit state. The open-circuit state causes the base robot load driver or relay to terminate power delivery from the base robot load power source to the base robot load, and simultaneously causes the module robot load driver or relay to terminate power delivery from the module robot load power source to the module robot load.

[00116] Also, when any emergency stop button is activated, the base robot computing unit and/or module robot computing unit identifies which of the emergency stop button is activated and stores this information in the base robot memory and/or module robot memory. [00117] When the module robot is intentionally undocked from the base robot without activation of emergency stop button, e.g. interchanging with another module robot, completed operation of module robot, the intentional undocking causes the base robot, e.g. its software parameters, to be reconfigured during which the controllable switch of the base robot electrical circuitry is toggled, i.e. switch from connecting to the first base module interface to connecting to the load driver/relay of the base electrical circuitry. When the base robot is in this undocked, i.e. standalone, arrangement, the emergency stop line, which comprises the base electrical circuitry only, is in closed-circuit state. When any emergency stop button on the base robot, is activated, e.g. by an impact on a bumper of the base robot, the emergency stop line is caused to change from closed-circuit state to open-circuit state. This open-circuit state causes the base robot load driver or relay to terminate power delivery from the base robot load power source to the base robot load.

[00118] Sensor and computing unit placements may be re-arranged and/or replaced. For example, one of the computing units at the base robot may be moved to the module and/or cameras may be replaced with 3D Lidar. For example, the module robot may contain no microcontrollers or computing unit, instead the intermediate control may be performed by the base robot. For example, mini-form PC may be replaced with a System on a chip (SOC) that has input/output pins to interface with the cleaning directly.

[00119] Wheel biasing mechanism, alignment feature, and the centre driving wheel mechanism may be employed individually or in any combination. Advantages provided by each feature may be achieved or forgone accordingly. For example, if the spring mechanism is omitted, climbing capability is forgone but other functions may be retained; if the alignment or lead-in feature is omitted, ease of module assembly is forgone but other functions may be retained; if centre driving wheel mechanism is omitted (i.e. front or rear-wheel drive is used), on-the-spot turning capability is forgone but other functions may be retained.

[00120] Securing or locking the module robot to the base robot may be performed by any securing or locking mechanism, e.g. latch, rotary latch.

[00121] It is to be understood that the embodiments and features described above should be considered exemplary and not restrictive. Many other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the invention. Furthermore, certain terminology has been used for the purposes of descriptive clarity, and not to limit the disclosed embodiments of the invention.