Refuse collection vehicle and system therefor

Abstract

The invention provides a safety system for use with a refuse collection vehicle having a refuse storage body and a front cabin, the system operating to detect the presence of an object or person in the vicinity of the vehicle and communicate with a lifting operation system. The vehicle has a lifting mechanism for engagement with a refuse bin, the lifting operation system operable to move the lifting mechanism between a lowered position at which the bin is on the ground in front of the vehicle and a raised position for discharge of the bin contents into the interior of the refuse storage body. The safety system including one or more sensors able to monitor an area in the vicinity of the vehicle where the lifting mechanism lifts and lowers bins and a controller operative to receive input data from said at least two sensors and process said data to determine the presence of an object or person, the controller operative to control functioning of the lifting operation system in accordance with the determination by the controller. The invention further provides a vehicle incorporating such a safety system, such as a front loading refuse collection vehicle.

Claims

1. A safety system for use with a refuse collection vehicle having a refuse storage body, the system operating to detect the presence of an object or person in the vicinity of the vehicle and communicate with a lifting operation system, wherein the vehicle has a lifting mechanism for engagement with a refuse bin, the lifting operation system operable to move the lifting mechanism between a first, lowered position at which the bin is on the ground in front of the vehicle and a second, raised position for discharge of the bin contents into the interior of the refuse storage body, the safety system including: one or more sensors mounted on the vehicle able to monitor an area in the vicinity of the vehicle where the lifting mechanism lifts and lowers bins; and a controller operative to receive input data from the one or more sensors and process the data to provide a determination of the presence of an object or person, the controller further operative to control functioning of the lifting operation system in accordance with the determination by the controller, wherein, when an object or person is detected when the lifting mechanism is moving from said first, lowered position to said second, raised position, the controller prevents subsequent movement of the lifting mechanism towards said first, lowered position but does not prevent further movement toward the second, raised position.

2. A refuse collection vehicle equipped with the safety system of claim 1, having at least two said sensors mounted on the vehicle able to monitor an area in the vicinity of the vehicle where the lifting mechanism lifts and lowers bins, wherein the vehicle has a front cabin with two opposed sides defining right and left lateral extent of the cabin, each of a first and a second of said at least two sensors being positioned at a spacing of less than 300 mm from a respective side of the cabin.

3. A refuse collection vehicle equipped with the safety system of claim 1, having at least two said sensors mounted on the vehicle able to monitor an area in the vicinity of the vehicle where the lifting mechanism lists and lowers bins, wherein each of a first and a second of said at least two sensors has a front face, the front face having a position which is in the range of between 80 mm in front of an external part of the vehicle and 30 mm behind said external part of the vehicle.

4. A refuse collection vehicle equipped with the safety system of claim 1, having at least two said sensors mounted on the vehicle able to monitor an area in the vicinity of the vehicle where the lifting mechanism lifts and lowers bins, wherein each of a first and a second of said at least two sensors is provided in a sensor unit, and each sensor unit is recessed into the external part of the vehicle.

5. A refuse collection vehicle equipped with the safety system of claim 4, wherein the vehicle is a front loading refuse collection vehicle and the external part of the vehicle is a front panel of the vehicle.

6. The refuse collection vehicle of claim 5, wherein the front panel is shaped such that a part of it protrudes forwardly of the front cabin further than other parts, and the first and second sensors are mounted such that their front faces are not positioned further forward than the protruding front part of the front panel.

7. The safety system of claim 1, wherein the controller can be selectively switched into an override mode to allow further movement towards said first, lowered position.

8. The safety system of claim 1, configured to be disabled or turned off when the vehicle is moving.

9. A refuse collection vehicle equipped with the safety system of claim 1, having at least three said sensors mounted on the vehicle able to monitor an area in the vicinity of the vehicle where the lifting mechanism lifts and lowers bins, the vehicle having a longitudinal centerline, wherein two of the sensors are, respectively, mounted on the sides of the front of the cabin, and at least one sensor is mounted centrally on the front of the cabin.

10. The safety system of claim 1, including a motion detector, wherein the controller is configured to process the received input data to determine a change of scene within the area, the change of scene indicative of the presence of an object or person.

11. A refuse collection vehicle equipped with the safety system of claim 1, having at least two said sensors mounted on the vehicle able to monitor an area in the vicinity of the vehicle where the lifting mechanism lifts and lowers bins, wherein the vehicle has a longitudinal centerline and a first and a second of the at least two said sensors are each spaced at least 800 mm from said longitudinal centreline.

12. The safety system of claim 7, wherein the system is configured to provide an audible alarm and a visual alert to an operator to provide a warning to an operator of the lifting operation system if the override mode is selected, to prompt that further operation be carried out with caution.

13. The safety system of claim 1, wherein the controller is integrated into one or more of the sensors.

14. The safety system of claim 1, in combination with an automated lifting operation system incorporating programmed control software, wherein the output from the safety system is used as an input to the control software.

15. A refuse collection vehicle including the safety system of claim 1.

16. A safety system for use with a refuse collection vehicle having a refuse storage body, the system operating to detect the presence of an object or person in the vicinity of the vehicle and communicate with a lifting operation system, wherein the vehicle has a lifting mechanism for engagement with a refuse bin, the lifting operation system operable to move the lifting mechanism between a first, lowered position at which the bin is on the ground in front of the vehicle and a second, raised position for discharge of the bin contents into the interior of the refuse storage body, the safety system including: one or more sensors mounted on the vehicle able to monitor an area in the vicinity of the vehicle where the lifting mechanism lifts and lowers bins; and a controller operative to receive input data from the one or more sensors and process the data to provide a determination of the presence of an object or person, the controller further operative to control functioning of the lifting operation system in accordance with the determination by the controller, wherein, when an object or person is detected when the lifting mechanism is moving from said second, raised position to said first, the lowered position, the controller prevents further movement of the lifting mechanism in that direction, but does not prevent movement back towards said second, raised position.

17. The safety system of claim 16, including a, wherein the controller is configured to process the received input data to determine a change of scene within the area, the change of scene indicative of the presence of an object or person.

18. A vehicle equipped with the safety system of claim 16, having at least two said sensors mounted on the vehicle able to monitor an area in the vicinity of the vehicle where the lifting mechanism lifts and lowers bins, wherein the vehicle has a longitudinal centerline and a first and a second of the at least two said sensors are each spaced at least 800 mm from said longitudinal centreline.

19. A refuse collection vehicle equipped with the safety system of claim 16 having at least two said sensors mounted on the vehicle able to monitor an area in the vicinity of the vehicle where the lifting mechanism lifts and lowers bins, wherein the vehicle has a front cabin with two opposed sides defining right and left lateral extent of the cabin, each of a first and a second of said at least two sensors being positioned at a spacing of less than 300 mm from a respective side of the cabin.

20. A refuse collection vehicle equipped with the safety system of claim 16 having at least two said sensors mounted on the vehicle able to monitor an area in the vicinity of the vehicle where the lifting mechanism lifts and lowers bins, wherein each of a first and a second of the at least two sensors has a front face, the front face having a position which is in the range of between 80 mm in front of an external part of the vehicle and 30 mm behind said external part of the vehicle.

21. A refuse collection vehicle equipped with the safety system of claim 16 having at least two said sensors mounted on the vehicle able to monitor an area in the vicinity of the vehicle where the lifting mechanism lifts and lowers bins, wherein each of a first and a second of said at least two sensors is provided in a sensor unit, and each sensor unit is recessed into the external part of the vehicle.

22. A refuse collection vehicle equipped with the safety system of claim 21, wherein the vehicle is a front loading refuse collection vehicle and the external part of the vehicle is a front panel of the vehicle.

23. The refuse collection vehicle safety system of claim 22, wherein the front panel is shaped such that a part of it protrudes forwardly of the front cabin further than other parts, and the first and second sensors are mounted such that their front faces are not positioned further forward than the protruding front part of the front panel.

24. The safety system of claim 16, wherein the controller system can be selectively switched into an override mode to allow further movement towards said first, the lowered position.

25. The safety system of claim 24, wherein the system is configured to provide an audible alarm and a visual alert to an operator to provide a warning to an operator of the lifting operation system if the override mode is selected, to prompt that further operation be carried out with caution.

26. The safety system of claim 16, configured to be disabled or turned off when the vehicle is moving.

27. A refuse collection vehicle equipped with the safety system of claim 16 having at least three said sensors mounted on the vehicle able to monitor an area in the vicinity of the vehicle where the lifting mechanism lifts and lowers bins, the vehicle having a longitudinal centreline, wherein two of the sensors are, respectively, mounted on the sides of the front of the cabin and at least one sensor is mounted centrally on the front of the cabin.

28. The safety system of claim 16, wherein the controller is integrated into one or more of the sensors.

29. The safety system of claim 16, in combination with an automated lifting operation system incorporating programmed control software, wherein the output from the safety system is used as an input to the control software.

30. A refuse collection vehicle including the safety system of claim 16.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In order that the present invention can be more readily understood, reference will now be made to the accompanying drawings which illustrate a preferred embodiment of the invention and wherein:

(2) FIG. 1 shows a side view of a conventional front-end loading refuse collection vehicle;

(3) FIG. 2 is a diagrammatic isometric view of the vehicle of FIG. 1 fitted with a detection system in accordance with an embodiment of the present invention, comprising two sensor units;

(4) FIG. 3 is a diagrammatic side view;

(5) FIG. 4 is a diagrammatic plan view;

(6) FIG. 5 is a diagrammatic plan view of the detection zones monitored by the detection system;

(7) FIG. 6 is a flow diagram illustrating the logic flow of an implementation of the invention;

(8) FIG. 7 is a front view of the vehicle of FIG. 1, showing the positioning of the sensor units;

(9) FIG. 8 is a diagrammatic plan view of the detection zones of a further embodiment of the invention, comprising three sensor units; and

(10) FIG. 9 is a schematic diagram of the components of the detection system and lifting control system in accordance with an implementation of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(11) The refuse collection vehicle 10 of FIG. 1 includes a refuse storage body 12 and a cabin 16 at the front. Towards its forward end, refuse storage body 12 has a top opening 14, accessible by way of an opening hatch or door(s).

(12) The front panel of cabin 16 is shown at 18, and a vehicle driver/operator is shown at 20.

(13) A lifting mechanism 30 provides the means by which refuse bins can be engaged, lifted, raised and bought over the top of cabin 16 to be emptied into refuse storage body 12 by way of opening 14. Lifting mechanism 30 operates under control of a lifting control system operated by operator 20 manipulating command controls in cabin 16, eg. by moving a control joystick or other suitable interface means.

(14) The lifting system comprises a pair of lifting arms 32, each pivotally connected to a side of the lower front part of the vehicle body front, and a pair of lifting forks 34. The movement of lifting arms 32 and lifting forks 34 is realised by operation of hydraulic cylinders (not shown) controlled by the lifting control system. The lifting control system is configured to move lifting arms 32 between a lowered position (corresponding to a bin positioned on the ground) to a raised position (corresponding to the bin positioned over vehicle top opening 14, rotation of lifting forks 34 about a lateral axis allowing control of the orientation of the bin. Commonly, operator 20 controls the operation by manipulating a joystick, movement in the X direction controlling the movement of lifting arms 32, movement in the Y direction controlling the rotation of lifting forks 34.

(15) When emptying a bin 40, the vehicle driver/operator positions vehicle 10 with bin 40 positioned forwardly thereof, and then uses the vehicle and lifting control system to engage lifting forks 34 with the bin (by way of fork slots 42 provided in the outer side walls of the bin), and then to raise lifting arms 32. This lifts bin 40 in a generally arcuate path up over cabin 16 and brings it to a position over top opening 14. The lifting control system operates during this travel to rotate lifting forks 34 in relation to lifting arms 32 as required to control the orientation of bin 40 as required, and then to invert the bin to dump its contents into refuse storage body 12 of the vehicle once lifting arms 32 have reached the raised position. Bin 40 is then returned to the ground by lowering lifting arms 32 to the lowered position in a reverse operation to the raising operation, and lifting forks 34 then withdrawn from slots 42.

(16) As shown diagrammatically in FIGS. 2-4, vehicle 10 is provided with sensor units 44, 46, each mounted to the front panel 16 below the windscreen, one mounted near the left hand side and one mounted near the right hand side of cabin 16. Each sensor unit 44, 46 includes an infrared illuminator and a sensor, arranged to monitor sensed volumes 45, 47, which covers the space generally in front of vehicle 10. Sensor units 44, 46 form part of a detection system to sense objects and persons in the vicinity of the front of vehicle 10 who may be at risk from movement of lifting mechanism 30 or bin 40. The detection system is operatively interconnected with the lifting control system, as explained in further detail below.

(17) In the view shown in FIG. 4, each sensor unit 44, 46 is shown directed generally at an angle to the longitudinal centreline of the vehicle, to cover a total area subtending around 130. Whilst this arrangement provides a wide field of view, it leaves unmonitored a triangular blind spot area 56, in the centre of the region where the bin is raised and lowered.

(18) The variant shown in FIG. 5 directs sensor units 44 and 46 generally forwardly (ie. in line with the centreline of the vehicle), which reduces blind spot area 56 significantly, while maintaining a suitably wide field of view. When reference is made in this specification to the vehicle's centreline, it will be understood that this refers to the centreline as seen in plan view (eg. in FIG. 5), the centreline thus representing a vertical plane aligned in the forward-rearward direction.

(19) Sensor units 44, 46 are used to monitor movement within sensed areas 45, 47, so that the detection system is able to determine that an object or person has entered the area in front of vehicle 10. In accordance with the logic of the detection system, the sensed areas are divided into a first, central zone 54 and a second, peripheral zone 52. In the embodiment illustrated, the first zone, which will be referred to as the Danger Zone, embraces the area directly in front of the front of cabin 16 for a distance of 2500 mm in front of the front panel 18 and a width of 3000 mm, which fully encompasses the lifting forks 34 and an engaged bin in the lowered position. The second zone, which will be referred to as the Warning Zone, embraces the area lateral of Danger Zone 54 up to a distance of 3500 mm from the vehicle centreline, and to a forward boundary 5000 mm in front of the front panel 18 of cabin 16. The Danger Zone and the Warning Zone combine to form a Monitored Zone.

(20) The Warning Zone thus provides an early warning alert to operator 20 if a person or object approaches the bin lifting/lowering area either from a lateral or from a forward direction.

(21) It will be understood that the above dimensions of the different zones is provided by way of example only, and will of course be selected as appropriate for the particular intended operation and the particular vehicle and bin size and type.

(22) Sensor units 44, 46 act as motion detectors, to provide input for the detection of an object or person in the Monitored Zone, and appropriate logic in the detection system (as described below) provides input to the lifting control system to determine the response to be taken.

(23) The position of bin 40 is based on a determination of the position of lifting arms 32 relative to the lowered position, and on the position of lifting forks 34. The lifting system includes rotational position sensors mounted on lifting arms 32 and lifting forks 34, used to feedback position to the lifting control system. Alternatively, position could be determined by inclinometers mounted on the arms and forks, or in accordance with the linear movement of the hydraulic cylinders that drive lifting arms 32 and lifting forks 34.

(24) If lifting mechanism 30 is lifting or lowering bin 40 between the lowered position and the position at which bin 40 clears the sensed volume 45, 47 (ie. around the position at which the bottom of the bin is level with the bottom of the windscreen of cabin 16), the detection system is disabled, or signals provided by the detection system do not affect the normal functioning of the lifting control system. Otherwise, the movement of the bin would be interpreted as the presence of an object or person, which would result in the lifting control system interrupting operation.

(25) Outside this bin movement range, the lifting control system is configured as follows.

(26) Lowering Operation

(27) When arms 32 are lowering (under command of operator 20), if a moving object is detected in Warning Zone 52 a suitable alert is provided to the operator. This is an audible alarm (slow beep), accompanied by a visual warning such as a flashing light, as well as a warning message on the in-cabin screen display (Object DetectedProceed With Caution). This thus prompts the operator to pay attention to the general area in front of the vehicle in continuing the lowering operation. However, the continued lowering operation is not interrupted. If the moving object is no longer detected on the Warning Zone, the alert ceases.

(28) When arms 32 are lowering (under command of operator 20), if a moving object is detected in Danger Zone 54 further downward movement of arms 32 and forks 34 is immediately stopped. This is accompanied by an audible alarm (fast beep) as well as suitable visual alerts (including a warning message on the operator's screen display (Object DetectedMachine Stopped. Check Work Zone). Any further lowering operation is disabled, meaning that when the operator inputs a command to lower bin 40, the lowering operation is locked out. However, the system is configured to allow the operator to lift arms 32 and/or forks 34 in such a situation, to allow them to be moved immediately if necessary to clear a hazard.

(29) To lower lifting arms 32 under these circumstances, the operator is required to actively override the system, eg. by actuating a manual override control on a control panel in cabin 16. This has the effect of disabling the detection system. The operator is thus prompted to very carefully check the area in front of the vehicle before taking this override action and continuing the lowering operation with caution.

(30) In such an operation, once lifting arms 32 have returned to the lowered position, the operator override automatically ceases, ie. the detection system can reactivate, to detect any moving objects during the next operation.

(31) Lifting Operation

(32) When arms 32 are lifting (under command of operator 20), if a moving object is detected in Warning Zone 52 a suitable alert is provided to the operator. This comprises audible/visual alerts discussed above with regard to the lowering operation (slow beep). This prompts the operator to pay attention to the general area in front of the vehicle in continuing the lifting operation. However, the continued lifting, bin emptying and lowering operation is not interrupted. If the moving object is no longer detected on the Warning Zone, the alert ceases.

(33) When arms 32 are lifting (under command of operator 20), if a moving object is detected in Danger Zone 54 a suitable alert is likewise provided to the operator. This comprises audible/visual alerts discussed above with regard to the lowering operation (fast beep and appropriate on-screen warning message), which prompts the operator to pay careful attention to the general area in front of the vehicle. The continued lifting and bin emptying operation is not interrupted.

(34) However, following detection of a moving object in Danger Zone 54, a subsequent lowering operation is disabled (and appropriate message displayed to the operator), meaning that when the operator attempts to lower bin 40, the lowering operation (ie. lowering of arms 32 or forks 34) in such a situation is locked out.

(35) Subsequent Lowering Operation

(36) To lower lifting arms 32 or lifting forks 34 under these circumstances, the operator is required to actively override the system, eg. by actuating a manual override control on a control panel in cabin 16. This has the effect of disabling the detection system (or, more accurately, signals received from the detection system are ignored, meaning that they do not affect the functioning of the lifting control system). The operator is prompted to carefully check the area in front of the vehicle before taking this override action and performing the lowering operation.

(37) In such an operation, once lifting arms 32 have returned to the lowered position, the operator override automatically ceases, ie. the functioning of the detection system can reactivate.

(38) The logic of the above operations is shown schematically in the flow diagram of FIG. 6.

(39) It will thus be understood that the detection system of the invention is programmed to identify any scene change caused by movement within the Monitored Zone and, if this movement is detected in Danger Zone 54 and the bin lifting system is in operation either to lift or to lower the bin lifting mechanism 30, to lockout any further lowering operation. Unless and until the operator overrides this lockout (by temporarily disabling the detection system), no further lowering operation is possible. This is an important feature of the present invention, as relying (for example) on the detection system recognising that movement has ceased in the Danger Zone, and then automatically resuming operation, or relying on the detection system only during lowering operations, could lead to risk. Very importantly, this avoids the risk that the bin lowering operation could be conducted or completed if a pedestrian were to enter the Danger Zone during a lifting or a lowering operation and then pass into blind spot area 56.

(40) Importantly, in order to provide maximum protection, the position of the sensors of sensor units 44, 46 is critical. The sensors need to be positioned such that the Danger Zone and Warning Zone are optimised. To achieve this, the sensors should be sufficiently spaced apart, preferably substantially across the full width of the front of the vehicle. The applicant has determined this as a minimum distance of 800 mm from the centreline of vehicle 10, preferably greater than 900 mm therefrom, more preferably more than 950 mm therefrom, and yet more preferably more than 1000 mm therefrom. This provides a very wide field of view, and importantly avoids or minimises the undesirable creation of blind spot areas at the corners of the front of the vehicle, which could give rise to a significant risk in the case of a pedestrian who might approach the Danger Zone around the right or left front corner of the vehicle.

(41) Stated in another way, the sensors should be sufficiently close to the lateral sides 17 of cabin 16 of vehicle 10 to avoid the creation of the blind spot areas discussed above. The applicant has determined that each sensor should be within at least 300 mm of the lateral side 17 of vehicle cabin 16, preferably within 200 mm therof, and ideally within about 120 mm thereof.

(42) FIGS. 5 and 7 set out the dimensions and spacings discussed above, with reference to an embodiment of the invention employed to a refuse collection vehicle comprising a Volvo FM4 cab chassis.

(43) The reader will understand that when discussing the position of a sensor, this refers to the position of the centre of the front lens where light is collected (see reference 61 in FIG. 7, and further discussion below).

(44) Further, in order to provide maximum protection, each sensor unit should be mounted to be close to the front panel 18 of the vehicle cabin 16. The applicant has determined that the front face of the sensor unit (which is generally just forward of the light collecting lens of the sensor) should be positioned in the range between 80 mm in front to 30 mm behind front panel 18. In the Volvo cab chassis embodiment, this was around 2 mm forward of the front panel.

(45) Preferably, the sensor units should be recessed into front panel 18 such that the front face of the sensor unit does not extend further than the front-most extent of panel 18 across the front of cabin 16 (generally, at the centreline of the cabin). As well as maximising the sensed zones, this assists in protecting the sensor units from damage in normal use.

(46) In the embodiment tested by the applicant, when viewed from the front of the vehicle, then, the sensor units are recessed into the front panel of the cabin, positioned above the headlights of the vehicle and close to the lateral sides of the cabin, with each sensor approximately 1044 mm from the vehicle longitudinal centreline (see FIGS. 5 and 7).

(47) Further, it will be understood that the mounting of the sensor units may include mounting fixtures such as vibration dampers or mechanisms to withdraw the sensor units when the detection system is not in use.

(48) In an alternative to the system described above, the detection system of the invention may employ more than two sensor units. For example, the system may use three sensor units, as diagrammatically shown in FIG. 8, in order to cover a greater overall area. In this arrangement, a sensor unit 44, 46 is mounted on each side of the front of cabin 16, and a third unit 58 is mounted centrally of the front of cabin 16. This provides three sensed areas 45, 47 and 59. In this arrangement, sensor units 44 and 46 are angled to each cover a lateral area rearward of the front of the vehicle cabin, while central sensor unit 58 embraces the region including the Danger Zone 54.

(49) The sensor units used in the detection system tested by the applicant were active infrared units. The sensors were 3D Smart Sensors supplied by IFM Efector Pty Ltd (part no. 03M151), each with an associated infrared illumination module (part no. 03M950). These devices provide 3D infrared imaging, and work by calculating the phase shift of the transmitted and received IR light across the field of view, producing a point cloud of the area monitored. As will be understood, each sensor unit could equally be a single integrated module, comprising both transmitter and receiver.

(50) The sensor module 60 (with its sensor 61) and the illuminator module 62 (with its illuminator 63) are mounted together in a robust protective housing, each module having a replaceable transparent front face (see sensor unit 46 in FIG. 7). The unit features a supply connection which provides power as well as connection of the digital and analogue outputs, and also features an Ethernet connection to communicate output data via industrial Ethernet networks (TCP/IP and EIP).

(51) The output from sensors 61 is processed by a 3D data processing algorithm in an onboard processor, to model the volume in front of the refuse vehicle, determine the Danger Zone and Warning Zone (see FIG. 5), and determine motion in each zone in accordance with programmed parameters. The onboard processor passes commands to the vehicle's lifting control system, and also passes commands to the sensor units (eg. to switch off the illuminator modules and/or the sensor modules, as discussed further below). It will be understood that the commands passed on from the onboard processor to the lifting control system may simply be limited to data signals indicating (a) that motion is detected in the Warning Zone and (b) that motion is detected in the Danger Zone, the absence of a signal indicating that no motion is detected. Any decisions based on that information may then be made by the vehicle's lifting control system.

(52) It will be understood that, although it is preferred that the detection system of the invention operates as a motion detection system, other modes are possible. For example, the processor of the detection system may be configured to interpret any IR reflection in the particular zone of interest (ie. the detection of any artefact in that zone) as indicating the presence of a person or object. Alternatively, the sensors may be proximity sensors, or any other suitable type of sensor.

(53) Illustrated in FIG. 9 are the functional units of the vehicle's detection and control system, and their interconnection. The onboard processor 70 is operatively connected with sensor units 44 and 46, and with lifting control system 75. Units 77 and 79 denote the control systems for lifting arms 32 and lifting forks 34. Unit 80 denotes the in-cabin screen display, while unit 85 denotes the provision of other alerts to operator 20. Unit 90 denotes the operator's command input control system (eg. comprising a joystick, override control, etc), while unit 95 denotes the control system responsive to vehicle locomotion (see below).

(54) As the skilled reader will understand, the onboard processor of the detection system may be provided as a separate unit, or may be built into the sensor units. Further, the onboard processor of the detection system and the vehicle's lifting control system could be provided in a single integrated computer system, rather than as two separate programmed controllers.

(55) The output of the sensors may optionally be displayed as an image on an in-cabin display, with any moving objects highlighted to increase visibility. Further, the data may be recorded for future analysis if required. The motion detector systems are configured to automatically turn on when the bin lift control system is activated.

(56) The detection system is configured to automatically switch on when the vehicle is started, hence turning on both the sensor and illuminator modules 60, 62 ready for use. When movement of the vehicle is detected (in accordance with measured speed of the wheels) the system automatically switches off the detection system (via controller 95), to ensure compliance with road safety regulations which prohibit forward-facing red lights on moving vehicles. When the vehicle comes to a halt, the detection system only switches on once again when the lifting control system is activated. It will be understood that switching off and switching on the detection system in response to locomotion may involve turning off just the illuminator modules 62, or may involve turning off the whole detection system (ie. including the sensor modules).

(57) The detection system of the invention can be retrofitted to existing refuse collection vehicles.

(58) Whilst the above embodiment concerns application of the invention to a front loader refuse collection vehicle, it will be understood that in many aspects the invention can equally be applied to other types of vehicle, and in particular to side loading refuse collection vehicles. Aspects described above which may be applied to side loader vehicles include: the projection of the sensors from the body of the vehicle; the recessing of the sensor units into the sides of the vehicle; the locking out of a subsequent lowering operation if an object or person is detected in a particular zone during a bin raising operation; the ability for a lifting operation if an object or person has been detected in a particular zone during a bin raising operation (although a lowering operation is locked out); the reactivation of the detection system during operation once a bin has cleared the sensed zone; the automatic interruption of the detection system when the vehicle moves; and the use of three or more sensors.

(59) The above description is provided by way of illustration only, and it will be understood that the broad scope and ambit of the invention embrace all modifications and variations thereto as would be apparent to persons skilled in the art.

(60) Throughout the description and claims of this specification the word comprise and variations of that word such as comprises and comprising, are not intended to exclude other additives, components, integers or steps.