Patent Description:
In the waste management industry, industrial and domestic waste is increasingly being sorted in order to recover and recycle useful components. Each type of waste, or "fraction" of waste can have a different use and value. If waste is not sorted, then it often ends up in landfill or incineration which has an undesirable environmental and economic impact.

Industrial waste may be passed to waste management centres because handling and disposing of waste is time consuming and requires specialist equipment. Accordingly, a waste management centre may sort waste to collect the most valuable and useful fractions. For example, industrial waste may include mixed wood and metal fractions (as well as other fractions) and sorted wood and metal fractions can be reused and sold to recyclers. Waste which is sorted into a substantially homogeneous fraction is more desirable and economical for recyclers. This is because less processing of the material is required before being recycled into new products and materials.

It is known to sort domestic and industrial waste in different ways. For many years waste has been manually sorted by hand on a conveyor belt. However hand sorting waste can be arduous and dangerous to the human sorter depending on the type of industrial or domestic waste being sorted. Furthermore, some waste sorting plants which use human sorters require multiple shifts in order to increase the output of sorted waste.

One approach for improving the safety and the output of waste sorting is to automate one or more aspects of the waste sorting. The automation can comprise a controller sending control and movement instructions to a manipulator for interacting with the physical objects. The combination of a controller sending control instructions to a manipulator can also be referred to as a "robot".

One such robotic waste sorting system is a "delta" robot suspended over a conveyor belt which moves objects to be sorted. The conveyor belt passes under the delta robot and within a working area of the delta robot. A working area of a robot is an area on a surface within which the robot is able to reach and manipulate an object. A working volume is the physical space within which the robot is able to move and manipulate an object. The working volume is determined by the height above the working area where the robot can manipulate an object.

The working volume / area can also include chutes which are not part of the surface of a conveyor belt.

A delta robot comprises a servo housing and a plurality of arms which are connected to one or more servos for moving the arms. The arms extend down from the servo housing to a base which is coupled to a manipulator. The arms are connected via universal joints at the base.

Whilst a delta robot can be relatively effective at picking small light objects, the delta robot is not suitable for lifting heavy objects. Furthermore since the manipulator is suspended from the servo housing, the servos must have sufficient power to move the manipulator and the object. This means that the manipulators coupled to delta robots must be as light as possible to increase the maximum lift capacity of the delta robot.

Disadvantageously, the dimensions of the working volume for a delta robot varies across the width of the working space. In particular, the working volume is an inverted cone and becomes narrower as the manipulator moves away from the servo housing. In practice, this may mean that a delta robot cannot manipulate objects at the same height across the width of a conveyor belt and that delta robots are only suitable for working with narrow conveyor belts. This can be problematic because objects can be piled on each other making identifying and picking objects harder. This can limit the design choices and use applications when using a delta robot for waste sorting.

A delta robot is not particularly robust and the universal joints of a delta robot are particularly susceptible to wear and malfunction. Another consideration of a delta robot is that the movement of one or more arms causes movement in the other arms. Accordingly, whenever a delta robot moves, control instructions must be sent to each servo because each arm must move when the manipulator of the delta robot is moved. The non-linear control instructions to move the arms of the delta robot means that increased computational processing is required to control and move the delta robot within the working area / working volume.

Another known robot for automatic sorting of waste is a "gantry" robot. A gantry robot comprises a frame or gantry which engages the floor and bridges over a working area such as a conveyor belt. The gantry supports the weight of the manipulator and an object that the manipulator grips. The gantry robot comprises one or more axes of control which move in a straight line (e.g. linear). Normally the axes of control of a gantry robot are arranged at right angles to each other.

A gantry robot may pick objects from the conveyor belt and drop the picked objects into a chute. A chute comprises an opening which is in communication with a bin or another conveyor belt for receiving a particular fraction of waste. The picked objects placed in the bin or on the conveyor belt can then be moved to another location or step in waste processing. This means a picked object of a certain waste fraction is dropped into the corresponding chute. Known gantry robots have a four or more chutes located at the four corners of the rectangular working space for receiving the different fractions.

A problem with these automatic sorting robotic systems is that when a manipulator moves towards the conveyor in the Z-axis, the manipulator can exert an excessive force on the conveyer belt or an object to be sorted. This can crush the object making a successful pick less likely or can damage the conveyer belt or the manipulator.

<CIT> discloses a manipulator having a pneumatic cylinder. A working chamber or cavity of the pneumatic cylinder is connected to the atmosphere by a throttle and a check valve, to vary the position of housing. Levers and are mounted on the gears and can diverge radially. <CIT> discloses a suction device with an air damper comprising an air cylinder, suction pad and drive arm. A piston is arranged in cylinder body having chambers A and B. Cylinder body moves relative piston as suction pad contacts the plate, compressing air in chamber B and ejecting air through discharge port to the surroundings. <CIT> discloses a robot for grasping bottles from a conveyor. Main shaft of vertical take-out device is inserted into slide bearing and has external spring. The spring urges take out member with suction pad downward. When the suction pad is pressed against the side surface of the bottle and a certain amount of force for lowering the elevating member is applied, the spring contracts to a predetermined length. <CIT> discloses a gripper with a compensation unit. A spring arrangement presses a compensation plate towards a holding region. A spherically operating compensation unit deflects first and only then the linearly operating compensation unit. It is disclosed that this compensation path allows the movement of the gripper to be braked in good time in the event of a collision before the total compensation path of the compensation unit has been utilized.

Embodiments of the present invention aim to address the aforementioned problems.

The present invention is defined by independent claim <NUM>, and preferred embodiments are defined in the dependent claims.

According to an aspect of the present invention there is a waste sorting manipulator comprising: a gripper assembly for interacting with one or more waste objects to be sorted within a working area; at least one servo for moving the gripper assembly with respect to the working area; and at least one slidable coupling mounted between the at least one servo and the gripper assembly for allowing relative movement between the at least one servo and the gripper assembly.

According to an aspect of the present invention there is waste sorting manipulator comprising: a gripper assembly for interacting with one or more waste objects to be sorted within a working area; at least one servo for moving the gripper assembly with respect to between the manipulator and the working area; and at least one slidable coupling mounted between the at least one servo and the gripper assembly for allowing relative movement between the at least one servo and the gripper assembly.

This means that the slidable coupling protects the manipulator and other parts of the waste sorting robot from being damaged if the manipulator descends rapidly downwards, for example, towards the conveyor belt.

Optionally the at least one servo is a servo configured to vary the height of the gripper assembly above the working area. Optionally the at least one servo moves the gripper assembly in a direction normal to the plane of the working area. Optionally, the gripper assembly slides relative to the at least one servo in a direction normal to the plane of the working area. This means that the slidable coupling protects the manipulator from colliding with the conveyor when the manipulator descends rapidly in the Z-axis.

Optionally the at least one slidable coupling compresses when the gripper assembly receives a force in a direction towards the at least one servo which is above a compression force threshold. Optionally the compression force threshold is very low and so the slidable coupling compress if the gripper assembly physically engages any object or other part of the waste sorting robot.

Optionally, the at least one slidable coupling extends when the gripper assembly receives a force in a direction away from the at least one servo which is above an extension force threshold. Optionally the compression force threshold is less than the extension force threshold. This means that the slidable coupling will compress more easily that it will extend. When the gripper assembly is being raised in the Z-axis, the slidable coupling will not extend before the gripper assembly is lifted. This avoids a sudden jerky movement when the slidable coupling fully extends.

According to the invention, the rate of compression of the at least one slidable coupling is greater than the rate of extension of the at least one slidable coupling. This means that the slidable coupling provides a dampening effect and the gripper assembly does not experience jerky movements irrespective of how the manipulator moves.

Optionally, the at least one slidable coupling comprises a first part coupled to the gripper assembly and a second part coupled to the at least one servo. Optionally there is a bearing mounted on either the first or second part. Optionally the bearing mounted on the first or second part slidably engages against the other of the first or second part. Optionally the first part and the second part are configured to slide relative to each other over a distance of <NUM> to <NUM>.

Optionally the first part is a rod and the second part is a hollow sleeve for receiving the rod.

Optionally there is a seal between the first part and the second part. Optionally the at least one slidable coupling comprises a directional ball valve, wherein the ball valve is configured to allow air to escape from the hollow sleeve when the at least one slidable coupling is compressed. In this way, the slidable coupling is also a pneumatic dampener. The slidable coupling using the ball valve and selective control of the air entering and exiting the hollow sleeve controls the rate at which the slidable coupling extends and compresses.

Optionally the manipulator comprises at least one sensor for determining that the gripper assembly has engaged an object. Optionally the at least one sensor is configured to detect changes in acceleration, velocity or position of the gripper assembly. This means that the gripper assembly can be controlled to stop moving in the Z-axis when the gripper assembly engages an object or the conveyor belt. The slidable coupling slides over a distance that means the latency time for stopping the servo means that the slidable coupling does not fully compress before the servo has stopping moving the gripper assembly.

Optionally, an actuator is arranged to move the gripper assembly towards the working area and the actuator is coupled to the at least one slidable coupling. Optionally, the actuator is coupled between the at least one slidable coupling and the at least on servo. Optionally, the at least one slidable coupling comprises a portion of the actuator. Optionally, the actuator is a pneumatic actuator. Optionally, the actuator and the gripper assembly are substantially aligned along the same longitudinal axis.

In another aspect of the invention, a waste sorting robot comprises a frame; and a waste sorting manipulator according to any of the previous embodiments wherein the manipulator is moveably mounted on the frame and the manipulator is moveable within the working area.

Optionally the waste sorting robot is a waste sorting gantry robot and the frame is a gantry frame.

Various other aspects and further embodiments are also described in the following detailed description and in the attached claims with reference to the accompanying drawings, in which:.

<FIG> shows a schematic perspective view of a waste sorting robot <NUM>. In some embodiments, the waste sorting robot <NUM> can be a waste sorting gantry robot <NUM>. In other embodiments other types of waste sorting robots can be used. For the purposes of brevity, the embodiments will be described in reference to waste sorting gantry robots, but can also be other types of robot such as robot arms or delta robots.

In some embodiments, the waste sorting robot <NUM> is a Selective Compliance Assembly Robot Arm (SCARA). The waste sorting SCARA <NUM> may move in the X, Y, and Z planes like the waste sorting gantry robot, but incorporate movement in a theta axis at the end of the Z plane to rotate the end-of-arm tooling e.g. the gripper assembly <NUM>. In some embodiments, the waste sorting robot <NUM> is a four axis SCARA robot <NUM> that consists of an inner link arm (not shown) that rotates about the Z-axis. The inner link arm is connected to an outer link arm (not shown) that rotates about a Z elbow joint (not shown). The Z elbow joint is connected to a wrist axis (not shown) that moves up and down and also rotates about Z. In some embodiments the waste sorting SCARA <NUM> comprises an alternative configuration which has the linear Z motion as the second axis.

For the purposes of brevity, the embodiments will be described in reference to waste sorting gantry robots <NUM>, but any of the other aforementioned robot types can be used instead or in addition to the water sorting gantry robot <NUM>.

The waste sorting gantry robot comprises a controller <NUM> for sending control and movement instructions to a manipulator <NUM> for interacting with the physical objects 106a, 106b, 106c. The combination of a controller sending control instructions to a manipulator can also be referred to as a "robot". The controller <NUM> is located remote from the manipulator <NUM> and is housed in a cabinet (not shown). In other embodiments, the controller <NUM> can be integral with the manipulator and / or a gantry frame <NUM>.

The manipulator <NUM> physically engages and moves the objects 106a, 106b, 106c that enters the working area <NUM>. The working area <NUM> of a manipulator <NUM> is an area within which the manipulator <NUM> is able to reach and interact with the object 106a 106b, 106c. The working area <NUM> as shown in <FIG> is projected onto the conveyor belt <NUM> for the purposes of clarity. The manipulator <NUM> is configured to move at variable heights above the working area <NUM>. In this way, the manipulator <NUM> is configured to move within a working volume defined by the height above the working area <NUM> where the robot can manipulate an object. The manipulator <NUM> comprises one or more components for effecting relative movement with respect to the objects 106a, 106b, 106c. The manipulator <NUM> will be described in further detail below.

The physical objects 106a, 106b, 106c are moved into the working area <NUM> by a conveyor belt <NUM>. The path of travel of the conveyor belt <NUM> intersects with the working area <NUM>. This means that every object 106a, 106b, 106c that is moving on the conveyor belt <NUM> will pass through the working area <NUM>. The conveyor belt <NUM> can be a continuous belt, or a conveyor belt formed from overlapping portions. The conveyor belt <NUM> can be a single belt or alternatively a plurality of adjacent moving belts.

In other embodiments, the physical objects 106a, 106b, 106c can be conveyed into the working area <NUM> via other conveying means. The conveyor can be any suitable means for moving the objects 106a, 106b, 106c into the working area <NUM>. For example, the objects 106a, 106b, 106c are fed under gravity via slide (not shown) to the working area <NUM>. In other embodiments, the objects can be entrained in a fluid flow, such as air or water, which passes through the working area <NUM>.

The direction of the conveyor belt <NUM> is shown in <FIG> by two arrows. The objects 106a, and 106b are representative of different types of objects to be sorted having not yet been physically engaged by the manipulator <NUM>. In contrast, the object 106c is an object that has been sorted into a particular type of object. In some embodiments, the manipulator <NUM> interacts with only some of the objects 106c. For example, the waste sorting gantry robot <NUM> is only removing a particular type of objects. In other scenarios, the manipulator <NUM> will interact and sort every object 106a, 106b, 106c which is on the conveyor belt <NUM>.

In some embodiments, the objects to be sorted are waste products. The waste products can be any type of industrial, commercial, domestic, or any other waste which requires sorting and processing. Unsorted waste material comprises, for example, a plurality of fractions of different types of waste. Industrial waste can comprise fractions of metal, wood, plastic, hardcore and one or more other types of waste. In other embodiments, the waste can comprise any number of different fractions of waste formed from any type or parameter of waste. The fractions can be further subdivided into more refined categories. For example, metal can be separated into steel, iron, aluminium etc. Domestic waste also comprises different fractions of waste such as plastic, paper, cardboard, metal, glass and / or organic waste.

A fraction is a category of waste that the waste can be sorted into by the waste sorting gantry robot <NUM>. A fraction can be a standard or homogenous composition of material, such as aluminium, but alternatively a fraction can be category of waste defined by a customer or user.

In some embodiments, the waste can be sorted according to any parameter. A non-limiting list of parameters for dividing unsorted waste into fractions is as follows: material, previous purpose, size, weight, colour, opacity, economic value, purity, combustibility, whether the objects are ferrous or any other variable associated with waste objects. In a further embodiment, a fraction can comprise one or more other fractions. For example, one fraction can comprise a paper fraction, a cardboard fraction, and a wood fraction to be combinable to be a combustible fraction. In other embodiments, a fraction can be defined based on the previous purpose of the waste object, for example plastic tubes used for silicone sealant. It may be desirable to separate out some waste objects because they are contaminated and cannot be recycled.

The objects are fed from a hopper or other stored source of objects onto the conveyor belt <NUM>. Alternatively, the waste objects are fed from another conveyor belt (not shown) and there is no source of stored waste objects. In this case, the additional conveyor belt can be fed manually from e.g. an excavator. Optionally, the objects 106a, 106b, 106c can be preprocessed before being placed on the conveyor belt. For example, the objects can be washed, screened, crushed, ripped, shaken, vibrated to prepare the material before sorting. Alternatively, the waste objects 106a, 106b, 106c can be sorted with another robot or mechanical device. The objects 106a, 106b, 106c can be optionally pre-sorted before being placed on the conveyor belt <NUM>. For example, ferrous material can be removed from the unsorted waste by passing a magnet in proximity to the conveyor belt <NUM>. Large objects can be broken down into pieces of material which are of a suitable size and weight to be gripped by the manipulator <NUM>.

The manipulator <NUM> is configured to move within the working volume. The manipulator <NUM> comprises one or more servos for moving the manipulator <NUM> in one or more axes. In some embodiments, the manipulator <NUM> is moveable along a plurality of axes. In some embodiments, the manipulator is moveable along three axes which are substantially at right angles to each other. In this way, the manipulator <NUM> is movable in an X-axis which is parallel with the longitudinal axis of the conveyor belt <NUM> ("beltwise"). Additionally, the manipulator <NUM> is movable across the conveyor belt <NUM> in a Y-axis which is perpendicular to the longitudinal axis of the conveyor belt <NUM> ("widthwise"). The manipulator <NUM> is movable in a Z-axis which is in a direction normal to the working area <NUM> and the conveyor belt <NUM> ("heightwise"). Optionally, the manipulator <NUM> can rotate about one or more axes. In some embodiments a gripper assembly <NUM> coupled to the manipulator <NUM> can rotate about a W-axis. The gripper assembly <NUM> is discussed in further detail below.

The directions of movement of the manipulator <NUM> within the working space along the X-axis, Y-axis and the Z-axis are shown by the two headed arrows with dotted lines. The manipulator <NUM> is moved with respect to the conveyor belt <NUM> by an X-axis servo <NUM>, a Y-axis servo <NUM> and a Z-axis servo <NUM> respectively along the X-axis, the Y-axis and the Z-axis. The servos <NUM>, <NUM>, <NUM> are connectively connected to the controller <NUM> and controller <NUM> is configured to issue instructions for actuating one or more servos <NUM>, <NUM>, <NUM> to move the manipulator <NUM> within the working space. The connections between the servos <NUM>, <NUM>, <NUM> and the controller <NUM> are represented by dotted lines. Each connection between the servo <NUM>, <NUM>, <NUM> and the controller <NUM> can comprises one or more data and / or power connections.

Since the directions of movement of the manipulator <NUM> are substantially perpendicular to each other, movement of the manipulator in one of the axes is independent of the other axes. This means that the manipulator <NUM> movement can be defined in a cartesian coordinate frame of reference which makes processing movement instructions by the controller <NUM> simpler.

As mentioned previously, the manipulator <NUM> is mounted on a frame <NUM>. In some embodiments, the frame <NUM> can be a gantry frame <NUM>. In other embodiments, the frame <NUM> can be other structures suitable for supporting the manipulator <NUM> above the working area <NUM>. For example, the frame <NUM> can be a structure for suspending the manipulator <NUM> above the working area with rods and / or cables. Hereinafter, the frame <NUM> will be referred to a gantry frame <NUM> but can be applicable to other frames for supporting a manipulator <NUM>.

The gantry frame <NUM> comprises vertical struts <NUM> which engage with the floor or another substantially horizontal surface. In some embodiments, the vertical struts <NUM> can be tilted upright struts. In this way, the tilted upright struts are angled to the vertical. The tilted upright struts may be required to mount the gantry frame <NUM> to the floor in a non-standard installation. <FIG> shows the gantry frame <NUM> comprising four vertical struts <NUM> coupled together by horizontal beams <NUM>. In other embodiments, the horizontal beams <NUM> can be tilted lateral beams <NUM>. This may be required if the waste sorting gantry robot <NUM> is being installed in a small or unusual space. In other embodiments, there can be any suitable number of vertical struts <NUM>. The beams <NUM> and struts <NUM> are fixed together with welds, bolts or other suitable fasteners. Whilst the horizontal beams <NUM> are shown in <FIG> to be located above the conveyor belt <NUM>, one or more horizontal beams <NUM> can be positioned at different heights. For example, one or more horizontal beams <NUM> can be positioned underneath the conveyor belt. This can lower the centre of mass of the gantry frame <NUM> and make the entire waste sorting gantry robot <NUM> more stable if the vertical struts <NUM> are not secured to the floor.

The beams <NUM> and the struts <NUM> are load bearing and support the weight of the manipulator <NUM> and an object 106a, 106b, 106c that the manipulator <NUM> grasps. In some embodiments, the beams <NUM> and struts <NUM> are made from steel but other stiff, lightweight materials such as aluminium can be used. The vertical struts <NUM> can each comprise feet <NUM> comprising a plate through which bolts (not shown) can be threaded for securing the struts <NUM> to the floor. For the purposes of clarity, only one foot <NUM> is shown in <FIG>, but each strut <NUM> can comprise a foot <NUM>. In other embodiments, there are no feet <NUM> or fasteners for securing the gantry frame <NUM> to the floor. In this case, the gantry frame rests on the floor and the frictional forces between the gantry frame and the floor are sufficient to prevent the waste sorting gantry robot from moving with respect to the floor.

The manipulator <NUM> comprises at least one movable horizontal beam <NUM> which is movably mounted on the gantry frame <NUM>. The moveable beam <NUM> can be mounted in a beam carriage (not shown). The moveable horizontal beam <NUM> is movably mounted on one or more of the other fixed horizontal beams <NUM> of the gantry frame <NUM>. The moveable horizontal beam <NUM> is movable in the X-axis such that the manipulator <NUM> moves in the X-axis when the movable horizontal beam moves in the X-axis. The moveable horizontal beam <NUM> is mounted to the fixed horizontal beams <NUM> via an X-axis servo mechanism <NUM>. In some embodiments, the servo <NUM> is coupled to the moveable horizontal beam <NUM> via a belt drive. In other embodiments, the servo is coupled to the moveable horizontal beam via a rack and pinion mechanism. In some embodiments, other mechanisms can be used to actuate movement of the moveable horizontal beam along the X-axis. For example, a hydraulic or pneumatic system can be used for moving the movable horizontal beam <NUM>.

The X-axis servo <NUM> can be mounted on the moveable beam <NUM> or on the fixed horizontal beams <NUM>. It is preferable for the X-axis servo to be mounted on the fixed horizontal beams <NUM> such that the X-axis servo does not have to exert force moving its own weight.

A manipulator carriage <NUM> is movably mounted on the moveable horizontal beam <NUM>. The manipulator shuttle <NUM> is moveable along the longitudinal axis of the movable horizontal beam <NUM>. In this way, the manipulator carriage <NUM> is movable in the Y-axis relative to the moveable beam <NUM>. In some embodiments, the manipulator carriage <NUM> comprises a Y-axis servo mechanism <NUM> for moving the manipulator carriage <NUM> along the Y-axis. In other embodiments, the Y-axis servo <NUM> is not mounted in the manipulator carriage <NUM> and manipulator carriage <NUM> moves with respect to the Y-axis servo. In some embodiments, the servo <NUM> is coupled to the moveable horizontal beam <NUM> via a belt drive. In other embodiments, the servo <NUM> is coupled to the moveable horizontal beam <NUM> via a rack and pinion mechanism. In some embodiments, other mechanisms can be used to actuate movement of the moveable horizontal beam along the Y-axis. For example, a hydraulic or pneumatic system can be used for moving the manipulator carriage <NUM>.

When the manipulator carriage <NUM> moves along the Y-axis, a gripper assembly <NUM> also moves in the Y-axis. The gripper assembly <NUM> is movably mounted to the manipulator carriage <NUM>. The gripper assembly <NUM> is movable in the Z-axis in order to move the manipulator <NUM> heightwise in the Z-axis direction.

In some embodiments, the gripper assembly <NUM> optionally comprises a Z-axis servo mechanism <NUM> for moving the gripper assembly <NUM> along the Z-axis. In other embodiments, the Z-axis servo <NUM> is not mounted in the gripper assembly <NUM> but is mounted in the manipulator carriage <NUM>. In this way, the gripper assembly <NUM> moves with respect to the Z-axis servo <NUM>. In some embodiments, the servo <NUM> is coupled to the gripper assembly <NUM> via a belt drive. In other embodiments, the servo <NUM> is coupled to the gripper assembly <NUM> via a rack and pinion mechanism. In some embodiments, other mechanisms can be used to actuate movement of the moveable horizontal beam along the Z-axis. For example, a hydraulic or pneumatic system can be used for moving the gripper assembly <NUM> as shown in <FIG> and <FIG> below.

As mentioned, the manipulator <NUM> as shown in <FIG> comprises a gripper assembly <NUM>. In one embodiment, the gripper assembly <NUM> comprises a pair of jaws <NUM> configured to grip objects 106a, 106b, 106c. A gripper assembly <NUM> comprising a pair of jaws <NUM> is also known as a "finger gripper. " The gripper jaws <NUM> are actuated with a servo (not shown) for opening and closing the jaws <NUM>. The servo for the gripper jaws <NUM> is connectively coupled to the controller <NUM> so that the controller <NUM> can actuate the opening and closing of the jaws <NUM>. In some embodiments, the gripper assembly <NUM> further comprises a rotation servo (not shown) to rotate the gripper assembly <NUM> and / or the gripper jaw <NUM> about the W-axis. In some embodiments the W-axis and the Z-axis are coaxial, but in other embodiments the W-axis and the Z-axis are offset This means that the gripper jaws <NUM> can be rotated to better grasp long thin objects across their narrow dimensions.

Additionally or alternatively in a more preferable embodiment, the gripper assembly <NUM> can be a suction gripper (as shown in <FIG>) for gripping the objects using negative pressure. The suction gripper can have a suction cup which is substantially symmetric about the Z-axis. This means that the suction gripper does not need to be rotated about the Z-axis to achieve an optimal orientation with respect to the objects 106a, 106b, 106c. This means that the gripper assembly rotation servo is not required with a suction gripper. In the case with an asymmetrical suction gripper <NUM>, the gripper assembly <NUM> comprises a rotation servo to rotate the gripper assembly <NUM> about the W-axis as previously discussed above.

In other embodiments, the gripper assembly <NUM> of the manipulator <NUM> can be any suitable means for physically engaging and moving the objects 106a, 106b, 106c. Indeed, the manipulator <NUM> can be one or more tools for grasping, securing, gripping, cutting or skewering objects. In further embodiments the manipulator <NUM> can be a tool configured for interacting with and moving an object at a distance such as an electromagnet or a nozzle for blowing compressed air.

As mentioned, the controller <NUM> is configured to send instructions to the servos <NUM>, <NUM>, <NUM> of the manipulator <NUM> to control and interact with objects 106a, 106b, 106c on the conveyor belt <NUM>. The controller <NUM> is connectively coupled to at least one sensor <NUM> for detecting the objects 106a, 106b, 106c on the conveyor belt <NUM>. The at least one sensor <NUM> is positioned in front of the manipulator <NUM> so that detected measurements of the objects 106a, 106b, 106c are sent to the controller <NUM> before the objects 106a, 106b, 106c enter the working area <NUM>. In some embodiments, the at least one sensor <NUM> can be one or more of a RGB camera, an infrared camera, a metal detector, a hall sensor, a temperature sensor, visual and / or infrared spectroscopic detector, 3D imaging sensor , terahertz imaging system, radioactivity sensor, and / or a laser. The at least one sensor <NUM> can be any sensor suitable for determining a parameter of the object 106a, 106b, 106c.

<FIG> shows that the at least one sensor <NUM> is positioned in one position. The at least one sensor <NUM> is mounted in a sensor housing <NUM> to protect the sensor <NUM>. In other embodiments, a plurality of sensors are positions along and around the conveyor belt <NUM> to receive parameter data of the objects 106a, 106b, 106c.

The controller <NUM> receives information from the at least one sensor <NUM> corresponding to one or more objects 106a, 106b, 106c on the conveyor belt <NUM>. The controller <NUM> determines instructions for moving the manipulator <NUM> based on the received information according to one or more criteria. Various information processing techniques can be adopted by the controller <NUM> for controlling the manipulator <NUM>. Such information processing techniques are described in <CIT>, <CIT>, <CIT>, <CIT> which are incorporated herein by reference.

Once the manipulator <NUM> has received instructions from the controller <NUM>, the manipulator <NUM> executes the commands and moves the gripper assembly <NUM> to pick an object 106c from the conveyor belt <NUM>. The process of selecting and manipulating an object on the conveyor belt <NUM> is known as a "pick".

Once a pick has been completed, the manipulator <NUM> drops or throws the object 106c into a chute <NUM>. An object 106c dropped into the chute <NUM> is considered to be a successful pick. A successful pick is one where an object 106c was selected and moved to the chute <NUM> associated with the same fraction of waste as the object 106c.

The chute <NUM> comprises a chute opening <NUM> in the working area <NUM> for dropping picked objects 106c. The chute opening <NUM> of the chute <NUM> is adjacent to the conveyor belt <NUM> so that the manipulator <NUM> does not have to travel far when conveying a picked object 106c from the conveyor belt <NUM> to the chute opening <NUM>. By positioning the chute opening <NUM> of the chute adjacent to the conveyor belt <NUM>, the manipulator <NUM> can throw, drop, pull and / or push the object 106c into the chute <NUM>.

The chute <NUM> comprises walls <NUM> defining a conduit for guiding picked objects 106c into a fraction receptacle (not shown) for receiving a sorted fraction of waste. In some embodiments, a fraction receptacle is not required at the sorted fractions of waste are piled up beneath the chute <NUM>. <FIG> only shows one chute <NUM> associated with the manipulator <NUM>. In other embodiments, there can be a plurality of chutes <NUM> and associated openings <NUM> located around the conveyor belt <NUM>. Each opening <NUM> of the different chutes <NUM> is located within the working area <NUM> of the manipulator <NUM>. The walls <NUM> of the conduit can be any shape, size or orientation to guide picked objects 106c to the fraction receptacle. In some embodiments, the successfully picked objects 106c move under the force of gravity from the chute opening <NUM> of the chute <NUM> to the fraction receptacle. In other embodiments, the chute <NUM> may guide the successfully picked objects 106c to another conveyor belt (not shown) or other means for moving the successfully picked objects 106c to the fraction receptacle.

Turning to <FIG>, another embodiment will be discussed. <FIG> shows a schematic perspective view of a waste sorting gantry robot <NUM>. The conveyor belt <NUM> is positioned between the gantry frame <NUM>. For the purposes of clarity, no objects 106a, 106b, 106c have been shown on the conveyor belt <NUM>.

The gantry frame <NUM> as shown in <FIG> comprises a different configuration and construction from that shown in <FIG>. In particular, the gantry frame <NUM> comprises two cabinets <NUM>, <NUM>. The cabinet <NUM>, <NUM> comprise internal struts and horizontal beams similar to those discussed in reference to the embodiments shown in <FIG>. However the cabinet structures <NUM>, <NUM> comprise sheet material <NUM> to cover the struts and the horizontal beams providing the walls, top and bottoms of the cabinets <NUM>, <NUM>.

The cabinets <NUM>, <NUM> provide shielding for the delicate parts to the manipulator <NUM> such as the servos (not shown for clarity). This helps protect the manipulator from be damaged from stray waste objects. Furthermore the cabinet structures <NUM>, <NUM>, provide a barrier between the moving parts and the human operator. This means that the human operator cannot accidentally stray into the working area <NUM> of the waste sorting gantry robot. The gantry frame <NUM> comprises at least one enclosure <NUM>, <NUM>. The enclosure <NUM>, <NUM> surrounds at least a part of the gantry frame <NUM>. In some embodiments, there can be a plurality of enclosures <NUM>, <NUM>, each surrounding one or more parts of the waste sorting gantry robot <NUM>. The enclosure <NUM>, <NUM> can be a solid sheet material or can be perforated so that one or more internal parts of the waste sorting gantry robot <NUM> are visible. The enclosure <NUM>, <NUM> for example, surrounds the chute <NUM> on three sides. The enclosure <NUM>, <NUM> also surrounds at least a portion of the manipulator <NUM>. In other embodiments, the enclosure <NUM>, <NUM> can completely surround and enclose the waste sorting gantry robot <NUM>. In this case, the enclosure <NUM>, <NUM> comprises openings for the waste sorting objects 106a, 106b, 106c to be conveyed into the working area <NUM>.

The manipulator <NUM> will now be discussed in more detail with respect to <FIG> shows a cross-sectional front view of the waste sorting robot <NUM>. <FIG> shows a close up of the manipulator <NUM> with the manipulator carriage <NUM> mounted on the moveable horizontal beam <NUM>. As mentioned previously, the manipulator carriage <NUM> is movable along the movable horizontal beam <NUM> to move the gripper assembly <NUM> across the conveyor belt <NUM> in the Y-axis.

The manipulator carriage <NUM> comprises the Z-axis servo <NUM> for moving the gripper assembly <NUM> in the Z-axis. The Z-axis servo <NUM> varies the height of the gripper assembly <NUM> above the conveyor belt <NUM> and the working area <NUM>. The Z-axis servo is coupled to a pinon (not shown) that engages with a rack <NUM> for moving the gripper assembly in the Z-axis. In some embodiments, the Z-axis servo can be coupled to other mechanisms for raising and lowering the gripper assembly <NUM>. For example the Z-axis servo can be coupled to a cable mechanism for moving the gripper assembly <NUM> up and down. An arrow on the rack <NUM> shows the direction that the gripper assembly <NUM> moves with respect to the Z-axis servo and the manipulator carriage <NUM> when the Z-axis servo is actuated.

The gripper assembly <NUM> moves in the Z-axis in order to accommodate different height objects 106a, 106b on the conveyor belt <NUM>. For example, a first object 106a to be sorted has a height H1 whereas a second object 106b to be sorted has a height H2. H1 is greater than H2 and so the gripper assembly <NUM> must move closer to the conveyor belt <NUM> and the working area <NUM> in the Z-axis for the second object 106b than the first object 106a.

In some embodiments, the gripper assembly <NUM> when fully extended along the Z-axis can physically engage the surface of the conveyor belt <NUM>. This means that the gripper assembly <NUM> can pick up objects which are flat or have a very low profile in the Z-axis. The arrangement in <FIG> shows that the gripper assembly <NUM> is able to travel a distance Z1 in the Z-axis downwards to the conveyor belt <NUM>. The maximum distance that the gripper assembly <NUM> can travel in the Z-axis due to the Z-axis servo <NUM> is between <NUM> to <NUM>. In some embodiments, the gripper assembly <NUM> can travel in the Z-axis <NUM>. In other embodiments the gripper assembly <NUM> can move any distance in the Z-axis, provided that the gantry frame <NUM> is configured accordingly.

The gripper assembly <NUM> as shown in <FIG> is a suction gripper <NUM>. The suction gripper <NUM> is in fluid communication with a pneumatic system <NUM> schematically represented in <FIG>. The pneumatic system <NUM> comprises at least one hose <NUM> for connecting the suction gripper <NUM> to the pneumatic system <NUM>. The pneumatic system <NUM> can be wholly or partially housed in the gantry frame <NUM> or alternatively remote from the gantry frame <NUM>. In some embodiments, the hose is an air hose <NUM> for providing a source of air to the suction gripper <NUM>.

The suction gripper <NUM> comprises a suction cup <NUM> having a side wall and a top wall and a suction mouth <NUM>. The suction mouth <NUM> of the suction cup <NUM> is arranged to engage with an object to be sorted 106a, 106b. The suction cup <NUM> comprises a hollow construction and a generally circular cross-section (across the Z-axis). In other embodiments, the suction cup <NUM> is elongate across the Z-axis and has a rectangular or oval cross-sectional shape.

As mentioned in some embodiments, the suction cup <NUM> can be elongate and / or asymmetrical about one or more axes. In this case, the gripper assembly <NUM> comprises a rotation servo to rotate the gripper assembly <NUM> about the W-axis as previously discussed in reference to <FIG>.

In some embodiments, the side wall of the suction cup <NUM> comprises a ribbed or concertinaed wall portion <NUM>. The ribbed wall portion <NUM> creates a resiliently flexible portion in the suction cup <NUM> such that the suction cup <NUM> preferentially compresses in the Z-axis. In this way, when the suction cup <NUM> descends in the direction of the Z-axis and engages the object 106a, 106b, the ribbed wall portion <NUM> helps absorb a force of the impact which protects the manipulator <NUM>.

The suction cup <NUM> is made from a resiliently deformable material such as silicon, rubber or other similar material. This means that the suction cup <NUM> can deform when the suction cup abuts an irregular shape. Accordingly, the suction cup <NUM> can make a better seal between a lip of the side wall and the object 106a, 106b to be picked.

The suction cup <NUM> is in fluid communication with a first air inlet <NUM> of a suction tube <NUM> for evacuating air from the space within the suction cup <NUM>. The suction tube <NUM> comprises an elongate side wall. The suction tube <NUM> comprises the first air inlet <NUM> at one end and an air outlet <NUM> at another end. The negative pressure for the suction gripper <NUM> is generated near the suction cup <NUM> of the suction gripper <NUM>, which avoids the need for a vacuum hose. The suction tube <NUM> comprises a second air inlet <NUM> which is in fluid communication with the air hose <NUM>. Accordingly, the second air inlet <NUM> introduces an air source into the suction tube <NUM> between the first air inlet <NUM> and the air outlet <NUM>.

The gripper assembly <NUM> is mounted to the Z-axis servo via a slidable coupling <NUM>. In some embodiments, the gripper assembly is mounted to the Z-axis servo via a plurality of slidable couplings <NUM>. Indeed, other embodiments, there can be any number of slidable couplings <NUM> between the gripper assembly <NUM> and the Z-axis servo <NUM>. The slidable coupling comprises a first part <NUM> coupled to the gripper assembly <NUM> and a second part <NUM> which is coupled to the Z-axis servo <NUM>. The first part <NUM> is fastened to the suction tube <NUM> of the gripper assembly <NUM>. In other embodiments, the first part <NUM> is fastened to any other component of the gripper assembly <NUM>. The second part <NUM> is fastened to the rack <NUM> of the Z-axis servo <NUM>. In some embodiments, the first and second parts are bolted, glued, welded, screwed respectively to the gripper assembly <NUM> and the rack <NUM> of the Z-axis servo <NUM> mechanism.

The first and second parts <NUM>, <NUM> of the slidable coupling <NUM> are arranged to slide with respect to each other. The relative movement of the first part <NUM> and the second part <NUM> is in a direction which is normal to the plane of the conveyor belt and / or the working area <NUM>. In other words, the first part <NUM> and the second part <NUM> move relative to each other in the Z-axis. The first and second parts <NUM>, <NUM> are elongate and each have longitudinal axis which are aligned along a longitudinal axis B-B (shown in <FIG>). In some embodiments the first and second parts <NUM>, <NUM> are parallel with the Z-axis. In some other embodiments, the first part <NUM> and the second part <NUM> are not parallel with the Z-axis, but tilted with respect to the Z-axis. In this case, when the first and second parts <NUM>, <NUM> slide relative to each other, a component of the movement is in the Z-axis.

The first and second parts <NUM>, <NUM> can slide relative to each other over a distance Z2 along the Z-axis. In some embodiments, Z2 is <NUM> to the full extent of the Z-axis travel, e.g. <NUM>. Preferably the first and second parts <NUM>, <NUM> slide relative to each other by <NUM>, e.g. Z2 = <NUM>. For domestic waste, most of the objects 106a, 106b to be sorted will only project up from the conveyor belt <NUM> approximately <NUM>. Some objects to be sorted 106a, 106b may have a dimension longer than <NUM>, however long thin objects will tend to topple over and lie flat on the conveyor belt <NUM>.

In some embodiments, the first part <NUM> is a rod and the second part <NUM> is a hollow sleeve for receiving the rod <NUM>. In some embodiments the hollow sleeve <NUM> and the rod <NUM> are aluminium extrusions, although the hollow sleeve <NUM> and the rod <NUM> can be made from any other suitable material such as steel. The slidable coupling <NUM> can be any suitable mechanism to let the gripper assembly <NUM> to move with respect to the Z-axis servo <NUM>. For example, the first part <NUM> can be a hollow sleeve and the second part <NUM> can be a rod. In other embodiments, both the first and second parts <NUM>, <NUM> can both be elongate elements, for example, rods which are slidably coupled to each other. The rods (not shown) can be arranged side by side and slide against their respective exterior surfaces. In other embodiments, the slidable coupling <NUM> can be a "lazy tongs" scissor mechanism.

The compression of the first part <NUM> with respect to the second <NUM> is limited by a catch <NUM>. The catch <NUM> is mounted part way down the side of the first part <NUM> and engages with a lip of the sleeve <NUM> of the second part. Additionally or alternatively the compression of the first <NUM> part with respect to the second part <NUM> is limited in the Z-axis by the rod <NUM> physically engaging the end of the hollow sleeve <NUM>.

In contrast, extension of the first part <NUM> with respect to the second part <NUM> is limited by a sleeve stop <NUM>. The sleeve stop <NUM> is mounted on the inside of the hollow sleeve <NUM> and engages with a reciprocal rod stop <NUM>. The sleeve stop <NUM> and the rod stop prevent the first and second parts <NUM>, <NUM> from being detached from each other when the slidable coupling <NUM> is fully extended.

In operation, the Z-axis servo <NUM> lowers the gripper assembly <NUM> towards an object 106a, 106b, to be picked. As the gripper assembly <NUM> engages the surface of the object 106a, the first part <NUM> and the second part <NUM> of the slidable coupling <NUM> move with respect to each other. This means that if the Z-axis servo <NUM> continues to lower the gripper assembly <NUM> before the controller <NUM> stops the Z-axis servo <NUM>, the gripper assembly <NUM> is not forced into the object 106a, 106b to be picked or the conveyor belt <NUM>. In this way, the slidable coupling <NUM> is a shock absorber that protects the manipulator <NUM> from collision with conveyor belt <NUM> or objects 106a, 106b. This prevents damage to the manipulator <NUM> and / or the conveyor belt <NUM>. Furthermore, since the slidable coupling <NUM> slides, the objects 106a, 106b to be picked are not crushed and this increases the likelihood that the suction gripper <NUM> makes a successful pick.

In some embodiments, the slidable coupling <NUM> comprises a rubber protective sleeve <NUM> ( as shown in <FIG>) which covers the slidable coupling <NUM>. In this way the rubber protective sleeve prevents dust and other debris damaging the slidable coupling mechanism <NUM>. Furthermore, the rubber protective sleeve helps absorb collision energy.

Turning to <FIG>, another embodiment will now be described. The arrangement as shown in <FIG> is substantially the same as the embodiments described in reference to <FIG>. However a difference is that the first part <NUM> and the second part <NUM> of the slidable coupling <NUM> are coupled together differently. The elements which are the same as previously discussed embodiments will have the same reference number.

The rod <NUM> of the first part comprises a first seal <NUM> and optionally a second seal <NUM>. The first and second seals <NUM>, <NUM> engage both the exterior surface <NUM> of the rod <NUM> and an interior surface <NUM> of the hollow sleeve <NUM>. The seals <NUM>, <NUM> are fixed to the exterior surface <NUM> of the rod <NUM> and the seals <NUM>, <NUM> slide along the interior surface <NUM> of the hollow sleeve <NUM>. Alternatively the seals <NUM>, <NUM> are fixed to the interior surface <NUM> of the hollow sleeve <NUM> and slide with respect to the exterior surface <NUM> of the rod <NUM>. Accordingly, the seals <NUM>, <NUM> make an air-tight seal between the rod <NUM> and the hollow sleeve <NUM>. In this way, rod <NUM> and the hollow sleeve <NUM> form a pneumatic shock absorber. The air in the hollow sleeve <NUM> is trapped by the seals <NUM>, <NUM> and creates a piston.

The hollow sleeve comprises a valve <NUM> for selectively controlling the airflow out and in of the hollow sleeve <NUM>. In some embodiments, the valve <NUM> is a ball valve <NUM> which allows air to freely escape from the hollow sleeve <NUM> when the rod <NUM> is compressed into the hollow sleeve <NUM>. When the rod <NUM> is pulled out of the hollow sleeve <NUM>, the ball valve <NUM> limits the rate that air can re-enter the hollow sleeve <NUM>. In alternative embodiments, the valve can be a rubber flap <NUM> (as shown in <FIG>) which rests over an air hole <NUM> connected to the interior of the hollow sleeve <NUM>. The rubber flap <NUM> flexes away from the hollow sleeve <NUM> when air exits the hollow sleeve <NUM>. When the rod <NUM> extends from the hollow sleeve <NUM>, the rubber flap <NUM> covers the air hole and slowly lets air enter the hollow sleeve <NUM>. This means that the threshold force required to extend the rod <NUM> with respect to the hollow sleeve <NUM> is greater than the threshold force required compress the rod <NUM> into the hollow sleeve <NUM>.

In some embodiments the threshold force required to compress the rod <NUM> into hollow sleeve <NUM> is approximately 1N. In some embodiments, there is a minimum threshold force required to be exerted on the suction cup <NUM> before the rod <NUM> will slide into the hollow sleeve <NUM>. This means that the slidable coupling <NUM> does not compress if the Z-axis servo <NUM> rapidly moves the gripper assembly <NUM>. In this way, the minimum threshold force required to compress the slidable coupling <NUM> is greater than the force experienced by the gripper assembly <NUM> when the Z-axis servo moves the gripper assembly at the maximum acceleration.

In some embodiments, the threshold force required to extend the rod <NUM> out of the hollow sleeve <NUM> is approximately 10N - 50N. This means that the gripper assembly <NUM> will slowly slide away from the Z-axis servo <NUM> as the slidable coupling <NUM> extends under the force of gravity. This difference in forces required to cause the sliding movement of the slidable coupling <NUM> means that the slidable coupling <NUM> will compress easily when engaging with and object to be picked 106a, 106b.

This means that objects experience minimum crushing force when the gripper assembly <NUM> descends on them in the Z-axis, and there will be a lifting force immediately when the gripper assembly <NUM> starts to move upwards in the Z-axis. If there was no dampening provided by the slidable coupling <NUM> then there will be no lifting force until slidable coupling <NUM> hits the end stop, at which point the full force is immediately exerted to the object. This could lead to a picked object 106c, falling off the suction gripper <NUM>.

The "shock absorber" functionality brought about by the ball valve <NUM> can be optionally achieved with other components. For example the first part <NUM> and the second part <NUM> can be coupled together with an air cylinder, a silicone oil shock absorber, a rubber dampener, and / or a compression spring. The slidable coupling extends softly due to the dampening effect and there will not be a jerky movement that can dislodge the picked object 106a, 106b from the suction gripper <NUM>.

As mentioned previously, the slidable coupling <NUM> is a dampener for absorbing shocks and forces that the gripper assembly <NUM> experiences. in some embodiments, the gripper assembly <NUM> can be mounted to a separate damper (not shown) in addition to the slidable coupling <NUM>. In this way, the dampening functionality can be carried out by the additional damper component. At the same time, the sliding functionality is still provided by the slidable coupling <NUM>. In some embodiments the damper is a pneumatic damper. The damper can be mounted to the slidable coupling <NUM>. In other embodiments, a separate pneumatic actuator can be used to provide the damping functionality.

<FIG> shows another embodiment of the slidable coupling <NUM>. <FIG> shows a cross-sectional side view of the gripper assembly <NUM>. The gripper assembly <NUM> is the same as the embodiments described in reference to <FIG> except that the slidable coupling <NUM> has a different structure.

The first part <NUM> is slidably coupled to the second part <NUM> by virtue of a plurality of wheels <NUM>. In some embodiments, there are a plurality of sets of wheels <NUM>, <NUM> arranged to engage the exterior surface <NUM> rod <NUM> at a plurality of locations along the rod <NUM>. Each set <NUM>, <NUM> of wheels <NUM>, comprises a plurality of wheels to keep the rod <NUM> aligned along the longitudinal axis of the hollow sleeve <NUM>. The wheels <NUM> as shown protrude slightly through the hollow sleeve <NUM>. However, in other embodiments the wheels <NUM> can be mounted within the hollow sleeve <NUM> between the rod <NUM> and the interior surface <NUM> of the hollow sleeve <NUM>. The bearings of the wheels <NUM> are not shown for the purposes of clarity. However, the bearings of the wheels <NUM> are coupled to the hollow sleeve <NUM> to fix the rotation of axis of the wheels with respect to the hollow sleeve <NUM>. In other embodiments, the bearing of the wheels <NUM> are coupled to the rod <NUM>.

In some embodiments, the wheels <NUM> have an increased frictional force in one direction of rotation e.g. clockwise when compared to the other direction of rotation e.g. counterclockwise. In this way, the difference in the forces required to rotate the wheels means that different forces are required to extend the rod <NUM> out of the hollow sleeve <NUM> and compress the rod <NUM> into the hollow sleeve <NUM>.

<FIG> show a cross sectional plan view of the slidable coupling <NUM> along the axis A-A. The wheels <NUM> engage the rod <NUM> along the external surface of the rod <NUM>. In some embodiments, there are four wheels <NUM> which engage each face of the square rod <NUM>. In some embodiments, the cross-sectional shape of the rod <NUM> is another shape such as triangular, hexagonal or any other shape. <FIG> shows another cross sectional plan view of the slidable coupling <NUM>. In this case the wheels comprise a groove <NUM> for receiving a corner <NUM> of the rod <NUM>.

Turning to <FIG>, another embodiment will be described. <FIG> shows a gripper assembly <NUM> which is similar to the gripper assembly <NUM> as described in reference to <FIG>, <FIG> and <FIG>. The gripper assembly <NUM> comprises at least one sensor <NUM> for determining when the gripper assembly <NUM> has engaged the object to be picked 106a, 106b. In some embodiments, the at least one sensor <NUM> is the Z-axis servo <NUM>. In this case, the Z-axis servo <NUM> provides measurement data as to the current and voltage being used by the Z-axis servo <NUM>. As the Z-axis servo <NUM> moves the gripper assembly <NUM> down towards the working area <NUM>, the Z-axis servo <NUM> will have a particular voltage and / or current profile.

When the gripper assembly <NUM> engages with the object to be picked, the slidable coupling <NUM> starts moving. Accordingly, the gripper assembly <NUM> decelerates as the slidable coupling <NUM> absorbs the kinetic energy of the downwardly descending gripper assembly <NUM>. As the gripper assembly <NUM> decelerates, the current and / or voltage profile of the Z-axis servo <NUM> changes. The controller <NUM> detects the changes in the voltage and / or current. At this point, the controller <NUM> determines that the gripper assembly <NUM> is in contact with an object to be picked and the Z-axis servo <NUM> should stop.

In some other embodiments, the at least one sensor <NUM> can be another sensor <NUM> for detecting movement of the gripper assembly <NUM> and / or engagement of the gripper assembly <NUM> and the object to be picked. For example, the at least one sensor can be an accelerometer mounted on the suction cup <NUM>. Alternatively, the sensor <NUM> can be a camera for detecting contact between the suction cup <NUM> and the object to be picked.

The Z-axis servo <NUM> and controller <NUM> have a latency when bringing the Z-axis servo to a stop. Advantageously the slidable coupling <NUM> can absorb the downward movement of the gripper assembly <NUM> in the time period between the gripper assembly <NUM> first touching the object to be picked and the Z-axis servo <NUM> stopping.

Advantageously, the slidable coupling <NUM> between the gripper assembly <NUM> and the Z-axis servo <NUM> provides a z-axis feedback of the gripper assembly <NUM> height above objects to be picked and / or the conveyor belt <NUM>. Accordingly, less computational processing for the manipulator needs to be made with respect to the Z-axis dimension because the mechanical arrangement of the slidably mounted gripper assembly <NUM> means that there will always be engagement of the suction cup <NUM> on the surface of the object 106a, 106b without damaging the gripper assembly <NUM>.

Accordingly, this means that the object identification by the controller <NUM> needs only occur in the plane of the conveyor belt <NUM> and the working area <NUM>. The controller <NUM> assumes that all the objects 106a, 106b are in the plane of the conveyor belt <NUM> and every pick is conducted at the conveyor belt <NUM> level. The slidably mounted gripper assembly <NUM> means that the controller <NUM> does not need to compute how high the objects 106a, 106b are in the Z-axis. This means the software can be simpler and less computational processing is required. In turn, this means that there is less latency in making picks and the throughput of the waste sorting robot <NUM> is higher.

Another embodiment will now be described with reference to <FIG> is a schematic front view of the gripper assembly <NUM> and manipulator <NUM>. The embodiment as shown in <FIG> is similar to the previously described embodiments except that the slidable coupling comprises a first slidable coupling <NUM> and a second slidable coupling <NUM>. The functionality of the first and second slidable couplings <NUM>, <NUM> is the same as the slidable coupling <NUM> described in reference to the previous embodiments. Having two slidable couplings <NUM>, <NUM> means that there is no offset between the slidable couplings <NUM>, <NUM> and the suction cup <NUM>. The suction gripper assembly <NUM> is mounted on a plate <NUM> connected between the slidable coupling <NUM>, <NUM>. This means that the gripper assembly <NUM> is more securely mounted to the manipulator <NUM>.

In some embodiments, the gripper assembly <NUM> comprises one or more bearings (not shown). The bearings are made from a low friction suitable material e.g. polyoxymethylene (POM plastic) rings. The bearings are mounted on the second part of the slidable coupling <NUM>, <NUM>, and the bearings slide against the aluminium of the first part <NUM>, <NUM>. In other embodiments the bearings can be mounted on the first part instead. In contrast to the embodiments using wheels described previously, the embodiments show in <FIG> mean that the engagement between the first part and the second part of the slidable coupling does not have any moving parts. This means that the slidable coupling <NUM>, <NUM> only moves when an object is being picked, and the manipulator <NUM> is moving slowly. When the manipulator <NUM> is moving fast, the slidable coupling <NUM>, <NUM> is typically not moving. In some embodiments, the total slide distance of the slidable couplings <NUM>, <NUM> is <NUM>. In some embodiments the slide distance can be varied as required.

The slidably mounted gripper assembly <NUM> can be used in conjunction with a waste sorting gantry robot or other types of waste sorting robots such as delta robots or robot arms. In other embodiments, the slidably mounted gripper assembly <NUM> as described with respect to the <FIG> can also be used with other types of sorting robot which are not waste sorting robots. For example, the slidably mounted suction gripper <NUM> can be used with industrial robots in the automotive industry, food industry etc..

Turning to <FIG> and <FIG>, other embodiments will now be described in further detail. <FIG> and <FIG> show a schematic front view of the gripper assembly <NUM> and manipulator <NUM>. The arrangement in <FIG> and <FIG> is the same as the embodiments described in reference to the <FIG>. However, manipulator <NUM> as shown in <FIG> and <FIG> does not have a Z-axis servo. Instead, the Z-axis servo is replaced with an actuator <NUM> which is coupled to the slidable coupling <NUM>. The actuator <NUM> is arranged to extend or retract and move the gripper assembly <NUM> towards or away from the working area <NUM>.

Similar to the previously described embodiments, the slidable coupling <NUM> comprises a first part <NUM> coupled to the gripper assembly <NUM> and a second part <NUM> which is coupled to the manipulator carriage <NUM> or Y-axis servo <NUM>.

The longitudinal axis C-C of the slidable coupling <NUM> is aligned with the longitudinal axis of the gripper assembly <NUM>. This means that when the gripper assembly <NUM> engages an object 106a, 106b, 106c, the downwards force resulting from the actuator <NUM> is substantially in line with point of contact of the suction cup <NUM> with the object 106a, 106b, 106c. This means that the chance of producing a turning moment on the object 106a, 106b, 106c during a picking operation is reduced and this increases the picking success.

In some embodiments, the actuator <NUM> is a pneumatic piston <NUM> which is coupled to the previously described pneumatic system <NUM>. The pneumatic system <NUM> comprises at least one first hose <NUM> for connecting the suction gripper <NUM> to the pneumatic system <NUM> and at least one second hose <NUM> for connecting the pneumatic piston <NUM> to the pneumatic system <NUM>. The control of the pneumatic piston <NUM> is similar to the previously discussed pneumatic system <NUM>. Whilst <FIG> shows the pneumatic piston <NUM> is coupled to the same pneumatic system <NUM>, in other embodiments, the pneumatic piston <NUM> can be coupled to a separate pneumatic system (not shown).

As shown in <FIG>, the moveable head <NUM> of the pneumatic piston <NUM> is fixed to the second part <NUM> of the slidable coupling <NUM> and the body <NUM> of the pneumatic piston <NUM> is fixed to the first part <NUM> of the slidable coupling <NUM>. When the pneumatic piston <NUM> is actuated, the moveable head <NUM> extends away from the body <NUM> of the pneumatic piston <NUM>. In this way, when the pneumatic piston <NUM> extends, the first part <NUM> and the second part <NUM> of the slidable coupling <NUM> move away from each other.

As shown in <FIG>, the first part <NUM> is a hollow sleeve <NUM> arranged to slide over the second part <NUM> which is an inner rod. This is similar to the previously described embodiments. Indeed, the slidable coupling <NUM> can optionally have one or more features of the structure as previously described in reference to <FIG>.

During operation, the previously described dampening effect can be achieved and allowing the first part <NUM> and the second part <NUM> to slide towards each other as the gripper assembly <NUM> engages an object 106a, 106b, 106c in the working area <NUM>. Optionally, the pneumatic piston <NUM> is not connected to the compressed air supply of the pneumatic system <NUM> as the gripper assembly <NUM> engages the object 106a, 106b, 106c. Alternatively, the air in the pneumatic piston <NUM> is allowed to escape to the atmosphere. In this case, the operation of the pneumatic piston <NUM> is similar to the functionality of the slidable coupling <NUM> as shown in <FIG>.

In an alternative embodiment, the dampening effect can be achieved by actively retracting the pneumatic piston <NUM> as the suction gripper assembly engages the object 106a, 106b, 106c. Advantageously this means the force of the impact between the suction cup <NUM> and the object can be dampened and the speed of the pick can be increased. This is because the pneumatic piston <NUM> retracts for dampening the force and then can continue to retract to lift the gripped object 106a, 106b, 106c in the Z-axis direction. This means that the pneumatic piston <NUM> is already moving away from the working area <NUM> and the pneumatic piston <NUM> does not have to change direction. In other words the pneumatic piston <NUM> has a dual functionality of the Z-axis actuator and a shock absorber during the picking operation.

In some embodiments, the pneumatic piston <NUM> comprises at least one piston sensor <NUM>. The piston sensor <NUM> detects movement, acceleration and or position of the moveable head <NUM> with respect to the body <NUM> of the pneumatic piston <NUM>. In some embodiments, the piston sensor <NUM> is one or more of the following sensors: a reed switch, a hall sensor, an anisotropic magnetoresistive sensor, a giant magnetoresistive sensor, or any other suitable detector for determining the status of the pneumatic piston <NUM> e.g. the position of the moveable head <NUM> with respect to the body <NUM>.

The piston sensor <NUM> is connected to the controller <NUM> similarly to the other previously described sensors <NUM>, <NUM> with respect to the embodiments shown in <FIG>. Accordingly, the controller <NUM> can control the position of the suction gripper assembly <NUM> in dependence on a signal received from the piston sensor <NUM>. The control of the servos, <NUM>, <NUM> and the pneumatic piston <NUM> to pick objects 106a, 106b, 106c is similar to the previously described control functionality described in respect of <FIG>.

In other embodiments, the actuator <NUM> is not a pneumatic piston, but is a mechanical linkage. The actuator <NUM> can be any suitable mechanism for extending the slidable coupling <NUM> towards the working area <NUM>.

Another embodiment will now be described in reference to <FIG> is the same as the arrangement as shown in <FIG> except that the slidable coupling <NUM> has been modified. The pneumatic piston <NUM> itself forms part of the slidable coupling <NUM>. In particular, the body <NUM> of the pneumatic piston <NUM> is inserted and fixed within the hollow sleeve of the first part <NUM>. In this way, the body <NUM> of the pneumatic piston <NUM> forms a portion of the first part <NUM> of the slidable coupling <NUM>. The moveable head <NUM> is fixed to the manipulator carriage <NUM> or the Y-axis servo <NUM>. In this way, the moveable head <NUM> of the pneumatic piston <NUM> forms a portion of the second part <NUM> of the slidable coupling <NUM>. This means that the moveable head <NUM> and the body <NUM> of the pneumatic piston <NUM> slide with respect to each other when the pneumatic piston <NUM> is extended or retracted.

In another embodiment two or more embodiments are combined. Features of one embodiment can be combined with features of other embodiments.

Claim 1:
A waste sorting manipulator (<NUM>) comprising:
a gripper assembly (<NUM>) for interacting with one or more waste objects (106a, 106b, 106c), to be sorted within a working area (<NUM>);
at least one servo (<NUM>) for moving the gripper assembly (<NUM>) with respect to the working area (<NUM>; and
at least one slidable coupling (<NUM>) mounted between the at least one servo (<NUM>) and the gripper assembly (<NUM>) for allowing relative movement between the at least one servo (<NUM>) and the gripper assembly (<NUM>),
wherein the gripper assembly (<NUM>) is a suction gripper assembly having a deformable suction cup (<NUM>) and the deformable suction cup is configured to deform when the deformable suction cup engages the one or more waste objects to be sorted,
wherein the rate of compression of the at least one slidable coupling (<NUM>) is greater than the rate of extension of the at least one slidable coupling (<NUM>).