The present invention relates to a robotic seat-cleaning apparatus, preferably, but not necessarily exclusively, for cleaning seats arranged in rows on public transport, in particular for the cleaning of the seats of railway train carriages. The present invention also relates to a method of cleaning seats robotically.

There are many situations in which people are seated in rows arranged at intervals along an aisle . Examples are railway train carriages, in which seats are arranged in rows of two or three seats spaced either side of an aisle, and similarly passenger aircraft. Most commonly, the seats in a row all face in the same direction and may be identical from row to row. Sometimes, the spacing between rows of seats may be varied from row to row, allowing greater spacing for seats in premium areas of the train or aircraft. Even then, the seats of each row are often identical.

As far as the UK is concerned, the railway business model requires the railway train carriages to be in almost constant use and most typically they are rented out to train operating companies. To ensure a high quality service, there is a need to provide regular cleaning of the seats, and this must be done to a high standard, in a short time, and at an acceptable cost. To date this has meant taking the carriages out of service for a short time and manually cleaning, in which one or more cleaning personnel will go along the carriage with a vacuum cleaner. Both the floor and seats must be cleaned. To improve the cleanliness, attempts have been made to simplify the layout of the seats and floor to enable the cleaning personnel to move more quickly, as well as optimising the design of the seats using easy to clean and hard wearing materials, removing areas where debris can be trapped or where spilt material can be absorbed. Manual cleaning is a relatively costly part of the process of maintaining a railway carriage, and as such is therefore an object of the present invention to provide an improved solution for maintaining the cleanliness of a train robotic seat-cleaning apparatus suitable for the cleaning of seating, for instance on public transport vehicles, in a manner which ameliorates the above problems. According to a first aspect the invention provides a robotic seat-cleaning apparatus for cleaning a plurality of seats arranged in at least one row, for example multiple rows arranged along an aisle in a railway carriage, comprising a moveable body, first actuator means for moving the moveable body, a cleaning head, a support mechanism that is connected to the movable body and supports the cleaning head, a second actuator means which in use moves the support mechanism in turn to cause movement of the cleaning head relative to the movable body, and a controller including a processor which in use processes operating instructions and generates at least one first output signal, the first actuator means in use responding to the first output signal to move the movable body into a preferred position relative to a row of seats to be cleaned, and in which the controller in use also produces at least one second output signal, the second actuator means responding to the second output signal to move the support mechanism and thereby cause the cleaning head to move vertically and along the surface of the row of seats, thereby at least partially cleaning the seats.

The invention therefore provides a robotic cleaning device that can clean the seats arranged in rows in a railway carriage or similar, reducing the amount of time that the cleaning personnel spend on cleaning the seats. The first actuator means may be within the moveable body, in order to create a more compact apparatus.

The preferred position may be predetermined or known, to provide a datum for the remainder of the movements of the cleaning head.

The controller may generate output signals that cause the robotic seat-cleaning mechanism to move in two distinct steps, a first step comprising movement of the movable body to the preferred position relative to a row of seats as determined by the value or values of the first output signal, and a second step comprising moving the cleaning head vertically and transverse to the seats to enable the cleaning head to clean the seats. During the second step the movable body may remain fixed in position. Once the cleaning head has cleaned the seats of a row, the processor may generate a first output signal that cause the movable body to move to a preferred position relative to a second row of seats, and repeating for each row of seats to be cleaned. The preferred position may comprise the moveable body being at a predefined position and orientation relative to the seats of the at least one row. Where there are multiple rows of seats, for instance spaced along an aisle, the processor may produce output signals that cause the movable body to be positioned at a respective preferred position for each row. This position may, for each row, place the movable body at a predefined distance and orientation relative to the seats of the row. Typically this position will be alongside the end of the seats of the row, or a small distance to the rear of the seats.

Once the cleaning head has cleaned the seats of a row, the processor may cause the second actuator means to move the cleaning head clear of the seats of that row, and subsequently to cause the first actuator means to move the main body into a preferred positon relative to a second row of seats to be cleaned.

This process may be repeated for each row of seats to be cleaned. Where there is one row of seats on each side of an aisle, the controller may cause the robotic seat cleaning apparatus to move along, and to clean, all the seats on one side of the aisle and then repeat the process for the seats on the other side of the aisle .

The controller may cause the moveable body to remain stationary during the second step, thereby providing a datum for movement of the support mechanism during the second stage.

The robotic seat cleaning apparatus may include a biasing means that biases the cleaning head into engagement with the surface of the seats when during cleaning.

The biasing means may act between the cleaning head and a part of the support mechanism. It may comprise a spring that acts in tension or a resilient element that acts in compression. Alternatively the cleaning head may be suspended from the support mechanism and the biasing means may comprise the weight of the cleaning head and any other component that is suspended with the cleaning head from the support mechanism. In a preferred arrangement, the apparatus provides powered movement of the cleaning head relative to the movable base in two orthogonal directions corresponding to movement vertically and along the row of seats, whilst the actuator does not provide powered movement of the cleaning head in the remaining orthogonal direction. This allows the head to be moved up and down over the seat back and across the row of seats. The desired movement of the cleaning head in the third orthogonal direction, as needed to move back and forth over the base of the seat, may be achieved by engagement between the seat base and a part of the apparatus such as the cleaning head or support mechanism. This movement may be constrained by the biasing means, with the movement in that direction being guided by engagement of the cleaning head or part of the support mechanism with seats of the row being cleaned.

The seat cleaning head may include various additional components such as guide bars, skirting, or other components which serve to prevent the vacuum strength presented to any particular portion of the seat being too great. Thus, these additional components of the cleaning head may additionally or alternatively be in engagement with the seat in order that weight may be borne by the seat, increasing efficiency of motion.

The processor may therefore generate output signals that cause the second actuator means to move the cleaning head over the seats of the row of seats in such a way that the cleaning head is biased into contact with the surface of the seats by the biasing means to achieve the movement needed to clean the seat base.

By only powering the movement in two directions relative to the base, and allowing the cleaning head to ride over the seat base freely under a biasing force for movement in the third orthogonal direction, the weight and complexity of the assembly is reduced compared with one in which the cleaning head is fully controlled in three dimensions. The cleaning head will accurately follow the contours of the surface of the seat back and seat base and the powered movement is merely to drag the cleaning head up the seat back or over the base and from side to side along the row. For example, the support mechanism may comprise a swing arm that is connected to a vertical pillar through an articulated joint, the swing arm hanging down from the joint and supporting the cleaning head that is suspended from the joint, the joint permitting the arm to swing in an arc that lies in a vertical plane that is parallel to the aisle, the second actuator means comprising a device for raising and lowering the hinged joint along the swing arm. The arm may be free to swing in the manner of a pendulum below the joint in an unpowered manner, i.e . not under the control of an actuator with the weight of the arm and cleaning head providing the biasing force. During cleaning the pivot point of the arm and the cleaning head may be positioned on opposing sides of an imaginary vertical plane that contains the portion of the seat being cleaned by the cleaning head, the arm being offset from its rest position.

The support mechanism may further comprise a horizontally extending boom that extends along the row of seats, perpendicular to the aisle, one end of the boom being connected to the lower end of the swing arm with the cleaning head being supported by a shuttle that is moved to and fro along the boom by the second actuator means.

The boom and shuttle may together be considered to comprise an elongate linear actuator of the second actuator means.

The cleaning head can thus be moved up and down, over the upright surface of a seat back in the row, by moving the joint up and down the pillar, and also moved along the boom to track across the seats in the row.

In an alternative, the boom may be connected to the pillar and the joint of the swing arm may be carried by the shuttle, allowing both the arm and the cleaning head to move across the seats in the row. The support mechanism may include a substantially horizontal guide rail along which the cleaning head, or swing arm, can slide, the guide rail being contoured to match the contours of a base of the seat. This rail will help partially support the cleaning head when the base is being cleaned, which may be beneficial where the cleaning head is to be held slightly clear of the seat base when cleaning. The support mechanism and second actuator means may therefore be arranged to provide only linear movement of the cleaning head in two orthogonal directions, with the cleaning head being free to move in the third orthogonal direction under guidance of the seats themselves constrained by the joint of the swing arm.

The applicant has appreciated that providing only two linear powered directions of movement greatly simplifies the construction compared with, say, a fully powered Cartesian or articulated robot. The applicant has appreciated that the contours of the seats themselves can be used to control some of the movement of the cleaning head. This is important in reducing the bulk and weight of the apparatus. It also reduces the accuracy with which the cleaning head must be positioned relative to the seat surface.

The height of the pillar may exceed the highest point of the seats of the row to be cleaned to enable the cleaning head to be raised to clean the uppermost surface of the seats. For instance, the top of the pillar may be at least 1.2m, or at least 1.5m or at least 1.8m above the floor.

In a preferred mode of operation, during the second cleaning step the cleaning head may be moved up or down to cover a vertical strip of at least one seat of a row before being moved horizontally to clean an adjacent strip, further horizontal movement being applied until the whole of the seats of a row are cleaned. When being moved along the row it may be fixed vertically, and when moved vertically it may be fixed in position along the row. The seat will therefore be cleaned in a sequence of passes over the surface of the seat.

The arm may include a further articulated joint located along the swing arm, for instance substantially midway along the arm, to allow the arm to bend, enabling the cleaning head to move along a horizontal path across a seat base even though the first joint is being moved vertically by the second actuator means. The articulated joint may be biased by a biasing means, such as a spring, into a normal rest position.

The second actuator means and support mechanism should provide sufficient range of movement of the cleaning head to track the cleaning head over the full base and upright seatback of the seats. A range of movement of at least lm, and up to 1.5m, may therefore be provided vertically, and up to lm or up to 2 metres horizontally away from the movable base.

The robotic seat cleaning apparatus may comprise an area of memory that can be read by the processor, and the memory may store machine readable instructions that determine how the movable base and cleaning head are moved when cleaning the rows of seats.

The instructions may include position information identifying the preferred position of the movable base relative to an end seat of a row of seats to be cleaned, and seat information indicative of one or more key dimensions of the seats that determine the control signals that are required to move the cleaning head over the seats of the row. It may also include information identifying the relative position of each row of seats where there are multiple rows along an aisle .

The instructions may comprise one or more sequences of movements of the actuators that will cause the cleaning head to clean a row of seats, each sequence being associated with a particular arrangement of seats, the program retrieving the appropriate sequence when the particular arrangement of seats to be cleaned is learnt by the apparatus.

The apparatus may learn which arrangement of seats is to be cleaned in a number of ways, for instance by being programmed by a user or by detecting the particular arrangements using one or more sensors of the apparatus.

The memory may store the position information permanently, semi-permanently or in an area of random access memory. The apparats may include a modem which permits the processor to retrieve the positon information from an external source, such as from a server connected to the World Wide Web.

The position information may indicate the relative distance between the base and predefined part of the row of seats, such as a rear most foot of the row located nearest he aisle, or a marker on an end face of the seat, for instance part of the seat back or base or arm (where provided). A marker may be fixed to the seat for this purpose . The robotic cleaning apparatus may include a user interface that enables a user to enter information identifying the type of vehicle to be cleaned, and the robotic cleaning apparatus may retrieve instructions that correspond to the arrangement of seats in that vehicle . The vehicle could be a train carriage, or a tram, or a plane or other multiple occupant vehicle.

The robotic cleaning apparatus may include sensing means for determining the arrangement of seats autonomously, such as a camera that captures an image of the seats and/or surrounding area, or an image of an identification code, or perhaps a global position sensor that determines the general location of the cleaning apparatus that would allow it to identify a room to be cleaned.

The apparatus may include a position guide, the moveable base being in the preferred position when the guide is in contact with a predefined part of the row of seats of the aisle . This may comprise a touch sensitive guide that produces a signal when it touches a part of the seat row such as the seat or a seat support, e.g. a leg or pedestal of the seats.

The reader will therefore appreciate that the apparatus of the invention, whilst primarily useful to clean a vehicle such as a railway carriage, could be used to clean some other arrangement of seats such as a music hall, or sports stadium or conference venue or lecture theatre.

To enable the robotic seat cleaner to determine its positon relative to the rows of seats, it may include at least one sensor such as a camera, the camera feeding images to a signal processor which in turn feeds image signals to the processor. The processor may employ image recognition to identify a part of the row of seats, or a marker on the seats or floor, or some other feature of fixed position, and from this determine the relative positon of the moveable body to the row of seats.

To further assist in control of movement of the main body, the robotic seat cleaning apparatus may include a gyroscope that generates a signal that is fed to the processor providing some position information. Once the position of the main body relative to the seats has been identified the processor may generate control signals that cause the first actuator means to correctly positon the moveable body at the preferred position relative to the seats. The first actuator means may comprise one or more electric motors, each of which is connected to a respective wheel or track that support the main body of the robotic seat cleaning apparatus. Preferably there are at least three spaced apart wheels, at least one of which is driven by the first actuator means. The body may therefore be able to move in two dimensions over a horizontal floor forming an aisle.

In a simple version, the first actuator means may only move the body in one dimension along an aisle, with an operator manually locating the body at the end of an aisle before cleaning starts. There may perhaps be a guide, such as a guide rail, that is fitted to the aisle to restrain the movement of the movable body along the aisle. The apparatus may include a sensor that detects the position of the body relative to the guide.

The second actuator means may also comprise one or more motors. The first and second actuators may be combined as a single actuator assembly, with one or more shared actuators.

The type of cleaning head that is fitted to the robotic seat cleaning apparatus will depend on the material used for the seats but most conveniently comprises a vacuum head, and further including a pipe for connecting the vacuum head to a source of vacuum.

The robotic seat cleaning apparatus may include a source of vacuum, by which we mean a source of negative pressure fluid, connected to the pipe . This may be permanently attached to the moveable body or support mechanism or may be releasable without the need for tools. For example, it may comprise a support for a domestic or commercial vacuum cleaner that can be attached to the movable body.

As an alternative, or additionally, the cleaning head may comprise an applicator for applying a cleaning agent, for example a cleaning sponge, and the apparatus may include a dispensing means for dispensing a cleaning fluid into or onto the applicator, such as water or a detergent or disinfecting fluid.

The cleaning head may be removable and the apparatus may include two different types of interchangeable cleaning heads, such as a vacuum head and a cleaning sponge.

The second actuator means includes at least one motor, preferably a stepper motor. The processor may produce output signals of a variety of different forms. For instance, the first output signal may comprise a co-ordinate in an X-Y plane, defining the position of the moveable base relative to a known datum that is fixed relative the seats. The second output signal may comprise a co-ordinate in a Y'-Z' plane, defining the position of the cleaning head or of the pivot point of the swing arm, with the datum being the position of the movable base in space or relative to a row of seats.

Alternatively the first and second output signals generated by the processor may be one and the same, or extracted from a single master output signal, comprising a full set of coordinates in a Cartesian X-Y-Z frame, with a further signal processing unit converting the value of the master output signal into the required position information for each of the moving parts of the support means. This is then used to generate the control signals for each actuator of the apparatus. The precise manner in which this will be done, based on the details given in this specification, will be readily apparent to the expert in the art of robot control, with the task being to control the position of the cleaning head (the end effector) to clean the seats.

To enable the cleaning personnel to safely move the robotic cleaning apparatus into a train or plane it may have a total weight of less than 23kg inclusive of the vacuum source . This allows it to be manually lifted without the need for any aids by one person.

The robotic seat cleaning apparatus may include batteries that power the actuators and processor but preferably is mains powered, receiving power from an external source. This helps keep the weight and the cost down. The actuators may be driven bv a shared motor. Such an arrangement may enable the apparatus to have a lower weight, which may be beneficial.

In a second aspect the invention provides a method of cleaning seats arranged in multiple rows, the method comprising:

Providing an autonomous robotic cleaning apparatus according to the first aspect and causing the robotic cleaning apparatus to move along the aisle cleaning the seats in the rows of seats. The method may comprise manually positioning the apparatus adjacent a first row of seats to be cleaned, and removing the apparatus after cleaning has been completed.

The method may comprise programming the robotic seat cleaning apparatus with program instructions that determine the movement of the seat cleaning apparatus that is needed to clean a defined arrangement of seats in a railway carriage of plane, and subsequently identifying the railway carriage or plane, the robotic seat cleaning apparatus retrieving the corresponding program instructions.

The method may comprise providing information to the cleaning apparatus identifying at least one feature of the seats to be cleaned, the cleaner in turn obtaining information that determines the required pattern of movement for cleaning the seats.

There will now be described, by way of example only, one embodiment of the present invention with reference to and as illustrated in the accompanying drawings of which:

Figure 1 is a plan view of the rows of seats in a train carriage;

Figure 2 is a detailed cut away view of a seat of the carriage; Figure 3 is a schematic of the components of a robotic seat cleaning apparatus that can be used to clean the seats of the carriage of Figure 1 and for cleaning other arrangements of seats;

Figure 4 is an illustration of a robotic seat cleaning apparatus that embodies the components shown in Figure 3 ; Figure 5 is a figure which shows, in break outs, the various parts of the apparatus of Figure 4 and their function; Figure 6(a) to (d) shows the movement of the apparatus during a cleaning operation of a row of seats;

Figure 7 is a flow diagram of a method of cleaning a single row of seats; and Figure 8 is a flow diagram of a method of cleaning plural rows of seats arranged at spaced locations along an aisle.

Figure 1 shows a plan view of a typical train carriage 1 that includes an aisle 2 along which passengers can move through the carriage. The aisle is shown bounded by a dashed line in the figure . On each side of the aisle 2 are nine identical rows 3 of seats 4, which two seats 4 in each row 3. Figure 2 shows each seat in more detail, with a base cushion and upright seat back of hard foam 5 covered in a layer of soft foam 6 and a hard wearing fabric upper surface 7. The seat is supported by legs, not shown, to form the fixed rows of seats. The back is generally perpendicular to the base .

Figure 3 shows schematically a robotic seat cleaning apparatus 10 that is suitable for cleaning the seats of a carriage 1 such as the one shown in Figure 1. The apparatus 10 comprises an energy source 1 1 such as a battery or mains power inlet, a plurality of servo motors and other actuators 12 split into a first actuator means and a second actuator means, a mechanism 13 that that supports an end effector tool comprising a cleaning head 14 that can be moved by the actuators, sensors 15 that determine the position of the support mechanism 13 and the position of the apparatus 10 in the environment, and a controller. The controller includes a processor 16 that receives signals from the sensors 15 and processes these under control of a program stored in an area of memory (not shown) to generate output signals. These signals are fed to the actuators 12, which in turn move the cleaning head to clean the seats. The processor and sensors and actuators allow the robotic cleaning apparatus to work autonomously to clean the seats. Figure 4 is an illustration of one prototype embodiment of the apparatus 10 of Figure 3 that falls within the scope of an aspect of the invention. The apparatus 10 has three main parts, starting from the bottom upwards; a movable base 17, the support mechanism 13 comprising a pillar 18 and a swing arm 19 that is suspended from the pillar 17, and the cleaning head 14. The controller and power source 1 1 are fitted to the movable base portion along with an optional vacuum source (not shown). The various parts of the apparatus can be seen in more detail in Figure 5 of the drawings.

In the prototype the movable base 17 comprise a Turtle bot type robot, with a platform 17a which in the prototype was made of medium density fibre board, that is carried by a set of wheels (not shown). The wheels are driven by the first actuator means in the form of an electric motor. The motor receives control signals from the processor 16, which in turn receives one or more first output signals from the signal processor. The processor 16 can therefore control the position of the movable base by varying the value of the first output signals fed to the motor controller. A gearbox, not shown, provides a transmission between the motor and the wheel. The movable base houses the controller and the power source .

Whilst the first actuator means in the described embodiment is provided within the moveable body, it may instead provide movement to the moveable body through external actuation. For example, the moveable body may be attached to a cable which is anchored to a fixed point. The cable may be driven so as to vary the length of cable between the fixed point and the moveable body, causing the moveable body to change position. Other actuation means, either internal or external to the moveable body may also be used.

Extending upwards from the platform 16a the vertical pillar comprises four parallel rods 19 which define a rectangular space there between. The pillar supports a box 20 which is suspended from ropes or cords 21 between the rods 19. The ropes 21 pass through a system of pulleys 22 at the top of the pillar and back down to the platform where they are wrapped around a guide wheel (not shown) that is turned by an electric motor. The motor forms part of the second actuator means and is controlled by a second output signal from the processor. The processor, by changing the value of the output signal can move the box up and down the pillar using the motor. The pillar has a height of approx. 1.8m, in excess of the top of the seats to be cleaned. The swing arm 19 is attached to the box and can pivot around an axle 21 that is located in a pair of bearing secured to the box so that the swing arm can swing in a single plane. When the moveable body is in position during cleaning the axis of the axle will extend in a horizontal plane and along the row of seats so that the arm swings back and forth towards and away from the face of the seatback. A spring connects the arm to the box, the spring becoming tensioned as the swing arm swings away from its vertical position of rest. The spring can be seen in Figure 5. At the end of the swing arm 19 furthest from the axle is a horizontal boom or arm 23 that carries a shuttle 24 or trolley that is restrained to move to and fro along a track in the boom 23. The movement of the shuttle 24 is controlled by a further part of the second actuator means, in the form of a motor which drives a belt attached to the shuttle . This motor may be located at the end of the boom 23 nearest the swing arm 19.

Attached to the shuttle 24 is a cleaning head. In this example the cleaning head comprises a vacuum pipe 25 and a vacuum head 26, the pipe 25 being long enough to connect to a vacuum cleaner that can be fitted to the platform. The boom 23 is attached to the swing arm 19 through a pivot that allows it to rotate around its long axis, and a further spring controls the rotation of the boom. The boom has a length equal to the length of the rows of the seats that are to be cleaned, in this example approx. 1.5m. The boom could be telescopic, with the second actuator means including an actuator that controls the length of the boom.

Seats in train carriages may be approximately 45cm wide each, and thus it is advantageous for the robotic seat cleaning apparatus to be able to reach at least 90cm in order to clean a set of two seats, as is commonly found within carriages. Where the apparatus may be required for use on a plane or other vehicle, it may be necessary to have a greater reach, for instance 2 metres or greater.

The robot cleaning apparatus is designed so that it can carry out a cleaning of a row of seats, or multiple rows of seats, with little or no human assistance. To achieve this, the processor 16 accesses the memory and in the memory are multiple sets of instructions that correspond to the arrangement of different types of railway carriage, or plane, or lecture theatre. Of course, a bespoke apparatus may be provided that works only with one type of seat and this may have only the one set of instructions. The instructions define a pattern of movement of the cleaning head that the processor must cause the cleaning head to follow to clean the seats. These instructions can be in many forms, but assuming that the processing means is pre-programmed to be aware of the width of the cleaning head and the maximum and minimum height of the head that can be achieved by moving the box, and the maximum distance the head can be moved along the row by the shuttle on the boom, the instructions could simply comprise a height and width dimension and an offset dimension that indicates the relative position of the cleaning head at the start of a clean. From these the processor can calculate the desired movement of the cleaning head.

The instructions could be calculated using a computer model of the seat layout, or the instructions could be learnt by an operator manually moving the cleaning head and the apparatus calculating position instructions from this learning stage.

Before cleaning, the apparatus first must choose the correct instructions for the carriage or other location in which it is to be used. To do this, it may have a user interface that allows an operator to input the required information, perhaps selecting the appropriate instructions from the memory.

Regardless of the layout of the seats in the row - whether they are tall back seats or short back seats, are narrow or wide, once the layout has been selected the processor may cause the seats to be cleaned in a methodical manner such as that explained below with reference to Figures 6 to 8.

Figures 6(a) to (d) show the movement of the cleaning head 26 by the actuator means under control of the processor 16 to clean a seat of the kind shown in Figure 2. As shown in Figure 6(a), prior to cleaning the box 20 is moved to the top of the pillar 18 and the vacuum is switched on. The processor 16 then generates output signals that are supplied to the motor controlling the position of the box 20, to cause the box 20 and hence the boom to move down the pillar. The boom 23 remains horizontal. The cleaning head 26 will start to contact the surface of the seatback, and as the box moves down the swing arm 19 will swing to allow the cleaning head to track the shape of the seatback. The spring between the swing arm and box forces the cleaning head onto the seat.

In the next step, shown in Figure 6(b) the processor continues to move the box down the pillar. At a certain position the end of the arm contacts a guide device fitted to the platform and will start to swing out as the head moves in the direction defined by the arm. The box continues to move down. When the head reaches the end of the guide, which may be indicated by an optional switch feeding a signal to the processor, the motor reverses and the box starts to be raised to the top of the pillar.

As the arm reaches the end of the guide it is returned to the vertical by the spring, as shown in Figure 6(c) . The box then rises to the topmost positon as shown in Figure 6(d). During this time the vacuum is running and the cleaning head, which contacts the seat surface, cleans the seat.

After the steps shown in Figure 6(a) to (d) are completed, the head is moved along the arm by a distance equal to the width of the cleaning head, and the steps shown in Figures 6(a) to (d) are repeated. This continues until the processor has moved the head along the full length of the boom to clean the whole row of seats.

The apparatus may include a number of sensors that detect when the edge of a row of seats has been reached by the cleaning head, and detect where the movable body is relative to the row of seats.

Figures 7 and 8 show in schematic form the process steps that can be carried out by the processor during a method of cleaning. The method steps of Figure 7 apply to cleaning of one row, and Figure 8 apply to cleaning of multiple rows. The processor simply needs to know details of each row, and how many rows and this may be stored in an area of memory or accessed using a connection wirelessly to a server that stores the information.

The reader will appreciate that certain steps require feedback from the sensors of the apparatus to determine when a position has been reached, such as an end of a row. However, this information may also or alternatively be obtained from a memory accessed by the processor if a prior knowledge of the type and arrangement of seats to be cleaned is known to the robotic seat cleaning apparatus. In a practical implantation, it is envisaged that the movable base may comprise a moulded an ABS plastic or metal body that houses the processor and parts of the first and second actuator means, as well as providing the support for the vacuum source. A total weight of below 23kg may be readily achieved, making the apparatus portable and easily lifted onto and off a train carriage.

A second embodiment of a robotic seat cleaning apparatus 1 10 is shown in Figure 9. The apparatus 1 10 comprises a moveable base 1 17 upon which is mounted a vertical pillar 1 18. At a distal end of the pillar 1 18 is a horizontal arm 127 along which may travel a shuttle 124. The shuttle 124 acts as a carrier for a vertical boom 128, at a lower end of which is mounted a swing arm 1 19 which is pivotable about an axle 121. The swing arm includes a vacuum head 126.

The horizontal arm 127 may be provided at a height above the top of the seats, such that the apparatus 1 10 may easily traverse between rows of seats, when necessary.

The combination of the horizontal arm 127, shuttle 124 and vertical boom 128 allow the cleaning head to be located in two dimensions. A third degree of freedom is given by the pivoting of the swing arm 1 19 about the axle 121 , which further enables the vacuum head 126 to adequately track the contours of the seat.

Although not shown, the movement of the shuttle, vertical boom, swing arm and/or vacuum head may be provided by a series of pulleys, linear or rotary actuators, or other actuation means. Furthermore, additional degrees of freedom may be provided to the vacuum head allowing it to rotate, translate or otherwise move in order to provide an improved cleaning action. For example, it may be desired to include a rotating or roller brush within the cleaning head to facilitate agitation of detritus.

Although the apparatus of the present invention has been described in relation to its ability to clean seats, it may also include features to enable floor cleaning. For instance, a further vacuum source may provide suction to a floor-facing cleaning head, which may be fixed or moveable in relation to the moveable base . Thus, a single device may provide both floor and seat-cleaning, removing the need for separate devices. The same vacuum source may be provided to both the vacuum head and the floor-facing cleaning head, to minimise weight.

Whilst the apparatus has included only a single cleaning head and associated features, it may be desired to include multiple cleaning heads, booms, and swing arms. For example, by providing two spaced apart cleaning heads, two adjacent seats could be cleaned at the same time and powered by the same actuators. Alternatively, forming the apparatus in a symmetric or substantially symmetric arrangement having two opposed booms, swing arms and cleaning heads could allow the apparatus to clean seats on both sides of a train carriage at the same time. This could provide time advantages over cleaning each side separately. It may save time and cost by providing an arrangement such as this where seats either side of an aisle could be cleaned simultaneously.