JP7464367B2 - Refuse collection truck - Google Patents

Description

The present invention relates to a garbage collection vehicle.

Conventionally, in a refuse collection vehicle, a refuse loading device is installed in a refuse input box installed at the rear of the vehicle chassis, and the refuse input from the refuse input port is scraped into the refuse input box by a rotating plate or a loading plate, and loaded into a refuse storage box. In addition, a monitoring system has been proposed that monitors people near the refuse input port to ensure safety by preventing workers who perform the refuse loading work of inputting the refuse into the refuse input port from being inadvertently caught in the garbage loading device (see, for example, Patent Document 1).

In the monitoring system described in Patent Document 1, a camera serving as an image acquisition unit is attached at a specified angle to the upper rear of the garbage dump box, and is adapted to capture an image of a specified area near the garbage dump opening. Then, while the garbage loading device is in operation, image data captured (acquired) by the camera is sent to an image processing device (person detection unit), and if it is determined in the image that a person has entered a preset no-entry area, the operation of the garbage loading device is stopped.

Japanese Patent No. 4283568

However, the mounting angle of the camera (image acquisition unit) attached to the upper rear of the trash bin may change due to collisions with objects during trash loading operations or vibrations during travel. If the camera's mounting angle changes, its capture range (image capture range) also changes, which may lead to situations where people cannot be detected in restricted areas or where people are detected frequently. However, in the past, there was no function to automatically detect the camera's mounting angle, so users had to check the camera's mounting angle themselves.

The present invention was made in consideration of the above-mentioned circumstances, and aims to provide a refuse collection vehicle that makes it easy to recognize whether the mounting angle of the image acquisition unit at the upper rear of the refuse bin has changed.

The present invention provides a means for solving the above-mentioned problems as follows: That is, the present invention is a garbage collection vehicle equipped with a garbage loading device disposed inside a garbage dump box, and an image acquisition unit attached to the garbage dump box for acquiring an image of the vicinity of a garbage dump opening of the garbage dump box, and based on the image acquired by the image acquisition unit, judges whether or not a person has entered a no-entry area near the garbage dump opening during a garbage loading operation, and a control unit that judges whether or not an attachment part attached to the garbage dump box has been detected in an attachment part detection area near the garbage dump opening and detects the position of the attachment part separately from the image acquisition unit, and a control unit that is electrically connected to the control unit. and an alarm unit connected to the control unit, wherein the control unit stops the operation of the garbage loading device when it determines that a person has entered the no-entry area during garbage loading operation, and the control unit is further configured to compare a first position in the image of the attachment part detected at a predetermined first timing during garbage loading operation with a second position in the image of the attachment part detected at a predetermined second timing during the garbage loading operation after the first timing, and to output a signal to the alarm unit to notify of an abnormality when a deviation between the first position and the second position exceeds an allowable value.

According to the above configuration, by detecting the change in the position of the attachment part based on the image acquired by the image acquisition unit, even if the attachment angle of the image acquisition unit at the upper rear of the garbage bin has changed, it is possible to easily recognize that the attachment angle has changed when loading garbage.

In the present invention, the attachment part is preferably an inlet table that is provided at the lower edge of the garbage inlet so as to be switchable between an upright state and a horizontal state. In this case, it is preferable that a horizontal state detection sensor is provided for detecting that the inlet table is horizontal, and the first timing or the second timing is determined to be when the horizontal state detection sensor detects the horizontal state of the inlet table. According to these configurations, when the inlet table is in an upright state, a change in the position of the inlet table cannot be detected, so that only when the horizontal state detection sensor detects the horizontal state of the inlet table, a change in the position of the inlet table is detected and a change in the attachment angle of the attachment part at the upper rear of the garbage inlet box is detected.

In the present invention, it is preferable that the device has a power source main switch for turning on and off the power source of the garbage loading device, and is configured so that turning on the power source main switch is the condition for the first timing . According to this configuration, since the garbage loading device is driven by turning on the power source main switch, even if the mounting angle of the image acquisition unit at the rear upper part of the garbage input box has changed, it is possible to reliably recognize that the mounting angle has changed when performing garbage loading work.

In the present invention, the control unit is configured to determine whether the second position is deviated from the reference value by using the first position as a reference value, and further, it is preferable that an adjustment switch is connected to the control unit to enable the reference value to be changed. Refuse collection vehicles come in a wide variety of specifications, and the mounting positions of image acquisition units such as cameras are not constant, so the shape and position of the refuse inlet reflected by the camera or the like fluctuates. For this reason, it is preferable to provide an adjustment switch to enable the reference value to be adjusted for each individual vehicle.

The refuse collection vehicle of the present invention detects changes in the position of the attachment parts based on images acquired by the image acquisition unit, so even if the attachment angle of the image acquisition unit at the upper rear of the refuse bin has changed, it is easy to recognize that the attachment angle has changed when loading refuse.

1 is a side view showing a refuse collection vehicle according to an embodiment of the present invention. FIG. 2 is a rear view of the refuse collection vehicle of FIG. 1 . FIG. 2 is an explanatory diagram of the operation of a garbage loading device installed in a garbage collection vehicle. FIG. 4 is a view taken along line X1 in FIG. 3 . FIG. 2 is a hydraulic circuit diagram of a garbage loading device of a garbage collection vehicle. FIG. 2 is a schematic diagram showing a control device and an image processing unit of a refuse collection vehicle and their input/output states. FIG. 13 is an explanatory diagram showing a worker loading garbage bags into a garbage inlet as seen from the side. FIG. 4 is an example of an image captured by a camera, showing first and second detection areas. 4 is a flowchart showing a flow of control executed by a control device in control of a garbage loading device based on image processing performed in a garbage collection vehicle. 4 is a flowchart showing a flow of control executed by an image processing unit in image processing control carried out in a refuse collection vehicle. 13 is a flowchart showing an example of an input port table recognition process executed by the image processing unit. 13 is an example of an image captured by a camera, showing an input port table detection area. FIG. 10 is a flowchart showing an example of a person recognition process executed by the image processing unit.

An embodiment of the present invention applied to a rotary type refuse collection vehicle will be described with reference to the drawings. In the following description, for convenience, the front, rear, left and right of the refuse collection vehicle will sometimes be simply referred to as "front, rear, left and right."

Figures 1 and 2 show a refuse collection vehicle 100 according to an embodiment of the present invention. In the refuse collection vehicle 100, a refuse collection box 2 and a refuse drop box 3 are provided on a chassis 1, and the rear opening of the refuse collection box 2 is connected to the front opening of the refuse drop box 3. The refuse drop box 3 is supported relative to the refuse collection box 2 by a left-right pivot 3a provided on the top of the box, and is tilted by a pair of left and right tilting cylinders (not shown).

A substantially rectangular trash inlet 4 for inserting trash G (see FIG. 8) is opened at the lower part of the back of the trash bin 3, and the trash inlet 4 is opened and closed by a tailgate 5 that can be raised and lowered. A switch box 6 for operating the trash loading device is provided on the left side of the trash inlet 4. A camera unit 7 is disposed above the trash inlet 4 to photograph the trash inlet 4 and the area nearby. The camera unit 7 is fixed to the top of the trash bin 3 via a support member 80 that protrudes rearward from the inclined rear surface (curved rear surface) 3b of the trash bin 3 disposed above the trash inlet 4.

More specifically, as shown in Figs. 2 to 6, the support member 80 is frame-shaped with base ends at both the left and right ends of the inclined rear surface portion 3b. The camera unit 7 is fixed to the support member 80 at a position that is the left-right center of the trash bin 3. The camera unit 7 has a camera 71 as an image acquisition unit, a detection lamp 73 as an alarm unit, and an operation lamp 72 as a second alarm unit.

The camera 71 is attached at a predetermined angle to the upper rear part of the garbage dump box 3. Specifically, the camera 71 is attached via a mounting bracket 75 in a recess 74 provided in the left and right central part of the camera unit 7. The camera 71 has an imaging lens 71a, and is attached to the mounting bracket 75 of the camera unit 7 so that the imaging lens 71a faces diagonally downward and can be adjusted up and down around a horizontal axis. On both the left and right sides of the recess 74 of the camera unit 7, fixed surfaces 7a are provided that are inclined upward and backward from the horizontal plane (inclined upward toward the rear of the vehicle). An operating lamp 72 is attached facing downward to the left fixed surface 7a. Also, a detection lamp 73 is attached facing downward to the right fixed surface 7a. In other words, the operating lamp 72 and the detection lamp 73 are provided on both the left and right sides of the camera 71 near the imaging lens 71a of the camera 71.

Next, as shown in FIG. 3, the inside of the garbage dump box 3 is equipped with a garbage loading device that loads the garbage G that has been dumped into the garbage storage box 2. This garbage loading device pushes the garbage dumped into the garbage dump box 3 into the garbage storage box 2 that is connected to the front of the garbage dump box 3. The garbage storage box 2 is provided with a garbage discharge device (not shown) that discharges the stored garbage. As the garbage discharge device, for example, it is possible to use a dump cylinder interposed between the chassis 1 and the garbage storage box 2 to tilt the garbage storage box 2 to discharge the garbage, or a discharge plate provided inside the garbage storage box 2 to move to the rear of the garbage storage box 2 by a discharge cylinder to discharge the garbage.

Next, the garbage loading device of this embodiment will be described in detail. The garbage loading device of this embodiment is configured as a so-called rotary garbage loading device, which scoops up garbage G by rotating a rotating plate (loading member) 10 and pushes it into the garbage storage box 2 by a pushing plate 20. A rotating shaft 11 is installed at the bottom inside the garbage input box 3 so as to extend in the width direction, and the base end side of the rotating plate 10 is fixed to this.

In the illustrated example, a hydraulic motor 13 capable of rotating forward and reverse is connected to the end of the rotating shaft 11 via a reduction mechanism 12. The rotation of this hydraulic motor 13 is torque-up by the reduction mechanism 12 and transmitted to the rotating shaft 11, and the rotating plate 10 rotates integrally with this rotating shaft 11, so that its tip moves back and forth along the bottom wall of the trash bin 3, which has a cross section formed in a roughly semicircular arc shape.

The pusher plate 20 is provided above the rotating plate 10 across the entire width of the trash bin 3, and is supported so that it can swing back and forth around a left-right swing shaft 21 provided at the top of the plate. The pusher plate 20 also has an extension 22 that extends above the swing shaft 21, and a pusher cylinder 24 is installed between the extension 22 and a support pin 23 in front of it, and the extension and contraction of the cylinder causes the pusher plate 20 to swing back and forth.

Specifically, as shown by the solid line in Figure 3, when the pusher plate 20 is at its most swung position toward the trash storage box 2 (advance limit position), the rotating plate 10 rotates upward without interfering with the pusher plate 20, and the pusher plate 20 subsequently swings toward the trash inlet 4. Then, even after the pusher plate 20 swings to its most swung position toward the trash inlet 4 and reaches the retreat limit position shown by the phantom line in Figure 3, the rotating plate 10 continues to rotate.

The rotating plate 10 rotates in this way, sweeping the garbage G into the garbage storage box 2 and stopping once at the set stop position extending forward toward the garbage storage box 2 as shown by the solid line in Figure 3. Then, the pushing plate 20 swings toward the garbage storage box 2, pushing the garbage G on the rotating plate 10 into the garbage storage box 2. Then, when the pushing plate 20 reaches the forward limit position again, the rotating plate 10 begins to rotate upward again.

By repeating the rotation of the rotating plate 10 and the swinging of the pushing plate 20 in this manner in synchronization with each other, a garbage loading operation is performed in which garbage G dropped into the garbage dump box 3 is continuously loaded into the garbage storage box 2. The configuration of the hydraulic circuit and control system for operating the rotating plate 10 and the pushing plate 20 in this manner will be described later.

Inside the trash bin 3, there are provided switches LS1 to LS4 for detecting the positions of the rotating plate 10 and the pushing plate 20. Specifically, as shown in FIG. 3, there are provided switches LS1 and LS2 that are turned on when the pushing plate 20 is at the forward limit position or the backward limit position, respectively, switch LS3 that is turned on when the rotating plate 10 is at the set stop position, and switch LS4 that is turned on when the rotating plate 10 rotates a predetermined angle in the positive direction (clockwise in FIG. 1) from the set stop position and that is turned off when it has rotated a further predetermined angle.

Switches LS1 and LS2 are adapted to detect a dog (not shown) provided at the end of the swing shaft 21 of the push-in plate 20, and switches LS3 to LS4 are adapted to detect a dog (not shown) provided at the end of the rotation shaft 11 of the rotating plate 10. For example, limit switches, photoelectric switches, and proximity switches can be used as switches LS1 to LS4. Switch LS4 is a sensor that detects the angle range Z from just below the front edge (upper edge) 4a of the garbage inlet 4 to the point where the rotating plate 10 rotates backward and descends to the closest position to the rear edge (lower edge) 4b of the garbage inlet 4, as shown by hatching in FIG. 3, and detects that the rotating plate 10 is operating near the garbage inlet 4.

Furthermore, as shown in Figs. 1 and 3, emergency stop buttons 60, 61 and an emergency stop plate 62 for stopping the operation of the garbage loading device are arranged near the garbage inlet 4. As shown in Fig. 1, an emergency stop button 60 (corresponding to switch SW1 in Fig. 6) is arranged on the side of the switch box 6 provided on the left side of the garbage inlet 4, and as shown by a dashed line in Fig. 3, an emergency stop button 61 (corresponding to switch SW3 in Fig. 6) is arranged on the right side of the garbage inlet 4. The emergency stop plate 62 is arranged to turn on and off the switch SW2 below the garbage inlet 4. Also, as shown in Fig. 2, a stop release switch 63 is arranged on the rear side of the switch box 6. This stop release switch 63 is arranged to turn on and off, for example, a momentary switch SW4. The stop release switch 63 is operated when releasing the emergency stop of the garbage loading operation of the garbage loading device described later.

2 and 3, the rear edge (lower edge) 4b of the garbage inlet 4 is provided with an inlet table 65 as an attachment part that can rotate around a horizontal axis 65a extending along the vehicle width direction. The inlet table 65 is provided above the emergency stop plate 62 and can rotate between a horizontal position shown by a solid line in FIG. 3 and an upright position shown by a two-dot chain line in FIG. 3. The inlet table 65 is in the upright position during travel. During garbage loading work, the inlet table 65 is rotated to a horizontal position by the worker, and garbage G can be temporarily placed on the inlet table 65 before being inserted into the garbage inlet box 3. The inlet table 65 is maintained in a horizontal state by stoppers 66, 66 provided on both the left and right sides of the emergency stop plate 62. Garbage bags and the like can be temporarily placed on the inlet table 65. The inlet table 65 is fixed in a horizontal position by stoppers 66, 66 provided on both the left and right sides of the emergency stop plate 62. One of the stoppers 66 (the left stopper 66 in this case) has a built-in horizontal state detection switch (horizontal state detection sensor) 66a that detects that the inlet table 65 is in a horizontal position. When the inlet table 65 comes into contact with the horizontal state detection switch 66a, detecting that the inlet table 65 is in a horizontal state, a detection signal is sent to the image processing unit 9.

- Control system for refuse loading device -
Next, a control system for operating the garbage loading device will be described with reference to Figures 5 and 6. This control system includes a hydraulic circuit for controlling the hydraulic pressure supplied to the hydraulic motor 13 and the push cylinder 24 of the garbage loading device, a control device PLC (programmable logic controller) for outputting control signals to the solenoid control valves V1 and V2 provided in the hydraulic circuit, and an image processing unit 9 as a person detection section for performing person recognition processing based on image data from a camera 71. The control device PLC controls not only the driving of the garbage loading device but also the driving of the garbage discharge device.

First, the hydraulic circuit will be described with reference to FIG. 5. This hydraulic circuit includes a hydraulic pump P, an oil reservoir T, an electromagnetic control valve V1 for controlling the pushing cylinder 24, and an electromagnetic control valve V2 for controlling the hydraulic motor 13. Driving force is transmitted to the hydraulic pump P by a PTO (power take-off) that extracts power from an engine (not shown) that serves as a drive source for driving the vehicle.

As an example, the solenoid control valves V1 and V2 are both 6-port, 3-position electromagnetic directional change valves. When the solenoid SOLa is excited by the control device PLC, the solenoid control valve V1 switches to the first communication position (upper position in Figure 5) and supplies hydraulic oil from the hydraulic pump P to the rod-side oil chambers of the pair of pushing cylinders 24. On the other hand, when the solenoid SOLb is excited by the control device PLC, the solenoid control valve V1 switches to the second communication position (lower position in Figure 5) and supplies hydraulic oil to the head-side oil chambers.

When hydraulic oil is supplied from the solenoid control valve V1 to the head side oil chamber, the pair of pushing cylinders 24 expand to swing the pushing plate 20 forward. On the other hand, when hydraulic oil is supplied to the rod side oil chamber, the pair of pushing cylinders 24 contract to swing the pushing plate 20 backward. Also, when neither solenoid SOLa, SOLb is excited, the solenoid control valve V1 returns to the neutral position (the center position in Figure 5).

When the solenoid SOLc is excited, the solenoid control valve V2 switches to the first communication position (lower position in Figure 5) to supply hydraulic oil to the forward oil chamber of the hydraulic motor 13, causing the hydraulic motor 13 to rotate in the forward direction and also allowing the push cylinder 24 to expand and contract. On the other hand, when the solenoid SOLd is excited, the solenoid control valve V2 switches to the second communication position (upper position in Figure 5) to supply hydraulic oil to the reverse oil chamber of the hydraulic motor 13, causing the hydraulic motor 13 to rotate in the reverse direction.

When neither solenoid SOLc nor SOLd is energized, the solenoid control valve V2 returns to the neutral position (the center position in FIG. 5). When both solenoid control valves V1 and V2 are in the neutral position, the hydraulic oil flows back to the oil reservoir T. In the illustrated hydraulic circuit, V3 is a check valve, and V4 is a relief valve for setting the upper limit of the discharge pressure of the hydraulic pump P.

Next, the input and output states of signals of the control device PLC and the image processing unit 9 will be described with reference to FIG. 6. First, power is supplied to the control device PLC by the battery BT. The ignition switch SWK of the garbage collection vehicle 100, the PTO switch (power source main switch) SWP, the relay coil R1, etc. are interposed in the current carrying line K2 that extends from the positive terminal of this battery BT to the right side of FIG. 6 and leads to the ground line K1.

The upstream end of the current carrying line K3 is connected so as to branch off from the current carrying line K2 midway between the ignition switch SWK and the battery BT, and a contact (relay switch) r1 of the relay coil R1 is provided on the upstream side (the side closer to the battery BT). A power lamp L is provided on this current carrying line K3, and when the relay coil R1 is excited and the contact r1 is closed, the power lamp L is turned on by passing electricity through the current carrying line K3.

The upstream end of the current carrying line K4 is connected so as to branch off from the current carrying line K3 midway between the contact r1 of the relay coil R1 and the power lamp L, thereby supplying power to the signal power supply section (not shown) of the control device PLC. In other words, when the contact r1 is closed, power is supplied to the control device PLC via the current carrying lines K3 and K4.

Furthermore, the control device PLC is always energized by the energizing line K5 branching off from the energizing line K4 while the garbage loading device is in the process of loading garbage. In other words, the energizing line K5 is a line for inputting a so-called loading continuation signal, and is provided with switches SW1 to SW3 that are opened and closed in response to the operation of the emergency stop buttons 60, 61 and the emergency stop plate 62 described above. When the energizing (i.e., input of the loading continuation signal) is cut off by these switches SW1 to SW3, the control device PLC turns off the output of the control signal for exciting the solenoids SOLa to SOLd of the electromagnetic control valves V1, V2. This causes the electromagnetic control valves V1, V2 to return to their neutral positions, and the operation of the garbage loading device is stopped.

In addition, multiple branch lines are connected to the current carrying line K4, and the above-mentioned switches LS1 to LS4 are installed in each of these branch lines. The signals from the switches LS1 to LS4 are input to the control device PLC, and the positions of the rotating plate 10 and the pushing plate 20 of the garbage loading device, in other words, the operating status, are detected based on these signals.

In addition to switches LS1 to LS4, the input side of the control device PLC is electrically connected to a loading switch (loading button) SW5 for cyclically operating the garbage loading device, a changeover switch SW6 for switching between the garbage loading operation of the garbage loading device and the garbage discharge operation of the garbage discharge device, a switch SW7 for tilting and opening the garbage input box 3, a switch (not shown) for selecting single or continuous garbage loading operation, and a switch (not shown) for operating the rotating plate 10 and the pushing plate 20 independently. The changeover switch SW6 is provided at the branch position where the current carrying line K5 branches off from the current carrying line K4, and the current carrying line K5 is connected to the loading side of the changeover switch SW6.

As mentioned above, the various switches are connected to the input side, while the solenoids SOLa to SOLd of the electromagnetic control valves V1, V2, etc. are connected to the output side of the control device PLC. The control device PLC is programmed to output signals to the corresponding solenoids SOLa to SOLd in order to operate the hydraulic motor 13, the pushing cylinder 24, etc., according to a preset procedure based on the signals input from the switches SW1 to SW3, LS1 to LS4, etc.

Specifically, when the garbage loading device is operating to load garbage, the ignition switch SWK and the PTO switch SWP on the current line K2 are both turned on, exciting the relay coil R1. This closes the contact r1 of the relay coil R1, and power is supplied to the control device PLC via the current lines K3 and K4, which makes the control device PLC operable and outputs control signals to the solenoids SOLa to SOLd as appropriate.

Solenoids SOLa to SOLd are excited in response to this control signal, and the positions of solenoid control valves V1 and V2 are switched appropriately, supplying hydraulic pressure to the hydraulic motor 13, the pushing cylinder 24, etc. This causes the hydraulic motor 13, the pushing cylinder 24, etc. to operate, and as described above, the rotation of the rotating plate 10 and the oscillation of the pushing plate 20 are repeated in sync with each other.

In detail, first, as shown by the solid line in Figure 3, when the push plate 20 is at the forward limit position and an ON signal is output from switch LS1, and the rotating plate 10 is at the set stop position and an ON signal is also output from switch LS3, a control signal is output from the control device PLC which has received a signal from the loading switch SW5, the solenoid control valve V2 is switched to the first communication position, and the hydraulic motor 13 starts normal operation. As a result, the rotating plate 10 starts to rotate upward.

After a predetermined period of time has elapsed, the control device PLC outputs a control signal to the solenoid SOLa of the electromagnetic control valve V1, switching the electromagnetic control valve V1 to the first communication position and causing the pushing cylinder 24 to begin contracting. This causes the pushing plate 20 to swing toward the rear trash inlet 4, and when the pushing plate 20 reaches its retraction limit position, an ON signal is output from the switch LS2.

In response to this, the control device PLC stops outputting a control signal to the solenoid SOLa, causing the solenoid control valve V1 to return to the neutral position and stopping the swinging of the pusher plate 20. While the pusher plate 20 is swinging, the rotating plate 10 continues to rotate and scrapes the garbage G into the garbage storage box 2, until the rotating rotating plate 10 reaches the set stop position and an ON signal is output from the switch LS3.

In response to this, the control device PLC stops outputting a control signal to the solenoid SOLc of the electromagnetic control valve V2, causing the electromagnetic control valve V2 to return to the neutral position and stopping the rotation of the hydraulic motor 13. The control device PLC also outputs a control signal to the solenoid SOLb of the electromagnetic control valve V1, switching the electromagnetic control valve V1 to the second communication position, and the pushing cylinder 24 begins to extend, causing the pushing plate 20 to begin swinging forward.

In this way, the pusher plate 20, which swings toward the trash storage box 2 in front, pushes the trash G on the rotating plate 10 into the trash storage box 2, and when it reaches the forward limit position, an ON signal is output from the switch LS1. In response to this, the control device PLC stops outputting a control signal to the solenoid SOLb, which returns the solenoid control valve V1 to the neutral position, and the extension operation of the pusher cylinder 24, i.e., the forward swing of the pusher plate 20, stops, and the series of operations ends.

As shown in FIG. 6, the upstream end of a current carrying line K6 is connected between the ignition switch SWK and the PTO switch SWP, and the image processing unit 9 is connected to the current carrying line K6. When the ignition switch SWK is turned on, power is supplied to the image processing unit 9 via the current carrying line K6. The image processing unit 9 is connected to the camera 71 of the camera unit 7 via the current carrying line K7. A reverse signal based on the driving operation of the vehicle is input to the image processing unit 9 via the current carrying line K8.

The image processing unit 9 includes a central processing unit CPU that executes a predetermined program to perform various controls, an image processing unit DSP that acquires image data from the camera 71 and performs image processing, a memory M that serves as a storage unit for storing data used in the central processing unit CPU and the image processing unit DSP, an image output unit VOP that receives commands from the central processing unit CPU and displays the results of image processing on a monitoring monitor 93 (see FIG. 1), a clock unit C that clocks the time of the data log, and a camera control unit (not shown) that controls the camera 71. The image processing unit DSP is an integrated circuit that performs image processing logic at high speed, and executes a routine for human recognition processing, for example, as shown in the flowchart of FIG. 11. The upstream end of the current carrying line K9 is connected so as to branch off from the current carrying line K3 upstream of the contact r1 of the relay coil R1, and power is supplied to the time carrying unit C via this current carrying line K9. For this reason, even when the ignition switch SWK is off, current is constantly being passed through the time carrying unit C.

The image processing unit 9 is also connected to a current carrying line K10 branching off from the current carrying line K5. This current carrying line K10 is a loading signal line that does not function during the garbage discharge operation of the garbage loading device for person recognition processing by the image processing unit 9, but functions during the garbage loading operation of the garbage loading device. The current carrying line K10 is connected to the loading side of the changeover switch SW6, and when the PTO switch SWP is on and the changeover switch SW6 is switched to the loading side, a loading line signal is input to the image processing unit 9. The image processing unit 9 is also connected to a current carrying line K18 branching off from the current carrying line K6, and a camera angle adjustment switch SW8 is interposed in this current carrying line K18. The image processing unit 9 is also connected to a current carrying line K19 branching off from the current carrying line K10, and a horizontal state detection switch 66a is interposed in this current carrying line K19.

An operation switch SWS is interposed between the image processing unit 9 and the control device PLC. The image processing unit 9 is provided with an output port for a person safety signal, and this output port is connected to the operation switch SWS by a current carrying line K16. The image processing unit 9 is also provided with an input port for a data log start signal, and this input port is connected to the operation switch SWS by a current carrying line K17. The operation switch SWS is also connected to a current carrying line K15 branched off from the current carrying line K10.

When the operation switch SWS is switched to the on side, the output port of the person safety signal of the image processing unit 9 is connected to the control device PLC via the current carrying line K16 and the current carrying line K12.

The person safety signal output from the image processing unit 9 is input to the control device PLC through the current carrying lines K16 and K12. However, if a person enters a no-entry area (second detection area A12 described below) during the garbage loading operation of the garbage loading device, the person safety signal is not output from the image processing unit 9 and the person safety signal is not input to the control device PLC. The control device PLC performs an emergency stop of the garbage loading operation of the garbage loading device, using the absence of input of the person safety signal as one of the conditions.

When the operation switch SWS is switched to the on side, the current carrying line K11 branched off from the current carrying line K6 is connected to the current carrying line K17. In this case, when the ignition switch SWK is turned on, the current carrying line K6 is energized, and a data logging start signal is sent to the image processing unit 9 via the current carrying lines K11 and K17. This triggers the execution of data logging.

On the other hand, when the operation switch SWS is switched to the OFF side, the current carrying line K10 is connected to the control device PLC via the current carrying line K15 and the current carrying line K12. In this case, when the loading line signal is input to the image processing unit 9, the voltage from the current carrying line K10 is input to the control device PLC instead of the person safety signal. Therefore, regardless of whether the image processing unit 9 recognizes a person in the no-entry area, the control device PLC recognizes that the person safety signal is always being input.

When the operation switch SWS is switched to the OFF side, no current is applied to the power line K17 and data logging does not start.

In addition, a switch SW4 corresponding to the stop release switch 63 is interposed between the image processing unit 9 and the control device PLC. The switch SW4 is interposed in the current carrying line K13 branched from the current carrying line K10. When the stop release switch 63 is not turned on, the switch SW4 is in the off state, and no signal is input to the control device PLC. On the other hand, when the stop release switch 63 is turned on, the switch SW4 is in the on state, and when a loading line signal is input to the image processing unit 9, the voltage from the current carrying line K10 is input to the control device PLC as an on signal for stopping release. Note that when the garbage loading device is discharging garbage, the loading line signal is not input to the image processing unit 9, and therefore the function of the stop release switch 63 is disabled.

When the control device PLC recognizes an on signal from the stop release switch 63, it is configured not to perform an emergency stop of the garbage loading operation of the garbage loading device, even if the input of the person safety signal from the image processing unit 9 is no longer present.

The image processing unit 9 is electrically connected to a pilot lamp (not shown) disposed around the driver's seat, and to an alarm unit disposed near the garbage inlet 4, which includes an operation lamp 72, a detection lamp 73, a recognition error warning lamp 81, and a camera angle abnormality warning lamp 82, and the lighting of these lamps is controlled by the central processing unit CPU. The image processing unit 9 is also connected to a buzzer 91 that outputs a backing up warning sound, and this control is also performed by the central processing unit CPU. The low potential sides of the operation lamp 72, the detection lamp 73, the recognition error warning lamp 81, the camera angle abnormality warning lamp 82, and the buzzer 91 are connected to the ground line K1 via the current carrying line K12.

In this embodiment, an operation lamp 72 and a detection lamp 73 are provided on both the left and right sides of the imaging lens 71a of the camera 71 (see FIG. 4). In principle, the operation lamp 72 is turned on (illuminated) when a loading line signal is input to the image processing unit 9. In principle, the detection lamp 73 is turned on (illuminated) when a loading line signal is input to the image processing unit 9 and a person is determined to be in the person detection area near the garbage inlet 4 by the person recognition process described below.

As shown in Figures 1, 7 and 8, a camera 71 is attached at a predetermined angle to the upper part of the back of the waste bin 3, in other words, above the waste inlet 4, with its imaging lens 71a facing diagonally downward and rearward. Figures 7 and 8 show a person H (worker) standing near the waste inlet 4, stretching both arms forward to load waste G (garbage bags in Figures 7 and 8). The camera 71 is originally used as a backup camera for the driver of the waste collection vehicle 100 to monitor the rear, and captures the waste inlet 4 and a predetermined area behind it, as shown in an example in Figures 7 and 8.

The optical axis of the imaging lens 71a of the camera 71 extends in the direction along the X1 line in FIG. 3, and is turned backward from a vertical downward direction to photograph the area behind the garbage inlet 4, photographing the person H and garbage G near the garbage inlet 4 from above. Based on the image data photographed (acquired) by the camera 71 and input to the image processing unit 9, the image processing unit 9 determines whether or not a person H, such as a worker, is present at the garbage inlet 4 and in the person detection area behind it (the area surrounded by the dashed line and the area surrounded by the solid line in FIG. 8). If the image processing unit 9 determines that a person H is present in the person detection area, the control device PLC determines whether or not to stop the operation of the garbage loading device.

Specifically, the area for detecting people for loading is divided into a first detection area A11 (shown by a broken line in FIG. 8) and a second detection area A12 (shown by a solid line in FIG. 8). The second detection area A12 is provided closer to the garbage inlet 4 than the first detection area A11 and functions as a no-entry area. The image processing unit 9 determines whether or not a person H is present in the first detection area A11 or the second detection area A12, and if it determines that a person H is present in the second detection area A12 as a no-entry area, it sends a stop signal to the control device PLC, and the control device PLC stops the operation of the garbage loading device. For example, the first detection area A11 is a normal area when an operator performs garbage loading work, and is set in a rectangular area near the garbage inlet 4. The second detection area A12 is set in a rectangular area between the front edge 4a and the rear edge 4b of the garbage inlet 4. This second detection area A12 is set to include at least a portion of the area surrounded by the front edge 4a, rear edge 4b, left edge 4c, and right edge 4d of the garbage inlet 4.

In addition, when the vehicle is reversing, the image processing unit 9 determines whether or not the person H is in the third detection area A2 (shown by a dashed line in Figs. 7 and 8) behind the garbage inlet 4. If it is determined that the person H is in the third detection area A2, the image processing unit 9 notifies the driver to alert him/her. The third detection area A2 is set to a rectangular area including the second detection area A12, the first detection area A11, and the area behind them. In addition, the monitor 93 displays, together with the image from the camera 71, a line corresponding to the outer edge of the first detection area A11 (shown by a dashed line in Fig. 8), a line corresponding to the outer edge of the second detection area (no entry area) Y12 (shown by a solid line in Fig. 8), and a line corresponding to the outer edge of the third detection area A2 (shown by a dashed line in Fig. 8).

- Image processing routine -
Next, a control routine based on image processing performed in the refuse collection vehicle 100 will be described with reference to the flowcharts of Figures 9 and 10. For convenience, Figures 9 and 10 show the control executed by the control device PLC shown in Figure 9 and the control executed by the image processing unit 9 shown in Figure 10 separately.

First, the flow of control executed by the control device PLC will be described with reference to the flowchart in FIG. 9. As shown in FIG. 9, in step S1 after starting, the operator switches the ignition switch (ACC power source) from off to on, and then in step S2, the operator switches the PTO switch SWP from off to on, turning on the power supply of the control device PLC. Next, in step S3, the control device PLC resets the stop release. Here, the stop release flag is reset to 0. In this way, the stop release flag is reset when the PTO switch SWP is turned on. The stop release flag is set based on the operation status of the stop release switch 63, and when the stop release switch 63 is operated from off to on, the stop release flag is set to 1.

Next, in step S4, the control device PLC determines whether the changeover switch SW6 is switched to the loading side. If the changeover switch SW6 is switched to the loading side (YES), the process proceeds to step S5. If the changeover switch SW6 is switched to the unloading side instead of the loading side (NO), the process proceeds to step S14.

In step S5, the control device PLC determines whether the stop release flag is 1, and if the stop release flag is 1 (YES), the process proceeds to step S8. On the other hand, if the stop release flag is 0 (NO), the process proceeds to step S6, where the control device PLC determines whether the operator has switched the stop release switch 63 from off to on. If the stop release switch 63 has been switched from off to on (YES), in step S7, the control device PLC sets the stop release flag to 1 and the process proceeds to step S8. If the stop release switch 63 has not been switched from off to on (NO), the process proceeds to step S10.

In step S8, the control device PLC excites the relay coil R2 and switches the relay switch r2 off. This causes the detection lamp 73 and the operation lamp 72 to be turned off in step S9.

Next, in step S10, the control device PLC determines whether the loading switch SW5 is on. If the loading switch SW5 is on (YES), the process proceeds to step S11, where the control device PLC executes the garbage loading operation of the garbage loading device. On the other hand, if the loading switch SW5 is off (NO), the control device PLC waits until the loading switch SW5 is on.

Next, in step S12, the control device PLC determines whether the emergency stop button 60, 61 is turned on. If the emergency stop button 60, 61 is turned on (YES), the process proceeds to step S13, and if the emergency stop button 60, 61 is turned off (NO), the process proceeds to step S15.

In step S13, the control device PLC executes an emergency stop of the garbage loading operation of the garbage loading device. Then, in step S14, if the power supply of the control device PLC remains on (NO), the control device PLC returns to step S4 and executes the processing from step S4 onwards again. On the other hand, if the power supply of the control device PLC is turned off in step S14 (YES), this routine is terminated (END).

If the emergency stop buttons 60, 61 are OFF (NO) in the determination in step S12 described above, in step S15, the control device PLC determines whether or not the rotating plate 10 of the garbage loading device is in the dangerous angle range Z1 (see FIG. 3). This determination is made based on the presence or absence of a signal from switch LS4. Then, if the signal from switch LS4 is ON and the rotating plate 10 of the garbage loading device is in the dangerous angle range Z1 (YES), proceed to step S16. On the other hand, if the signal from switch LS4 is OFF and the rotating plate 10 is not in the dangerous angle range Z1 (NO), proceed to step S18.

Next, in step S16, the control device PLC determines whether or not a person safety signal has been input from the image processing unit 9. The person safety signal is output from the image processing unit 9 to the control device PLC based on the processing of the image processing unit 9 in steps T8 to T14 and T16 to T19 described below. Specifically, if the operation switch SWS is on and a person is in the second detection area A12 during the garbage loading operation of the garbage loading device, the person safety signal is not output from the image processing unit 9 and the person safety signal is not input to the control device PLC (step T14).

On the other hand, if the operation switch SWS is off, if a person is not detected in the first detection area A11 or the second detection area A12 during the garbage loading operation of the garbage loading device, or if a person is detected only in the first detection area A11, a person safety signal is input to the control device PLC (steps T17, T19). If a person safety signal has not been input (YES), proceed to step S17, and if a person safety signal has been input (NO), proceed to step S18.

In step S17, the control device PLC determines whether the stop release flag is 0 or not. If the stop release flag is 0 (YES), the process proceeds to step S13, where the control device PLC executes an emergency stop of the garbage loading operation of the garbage loading device. On the other hand, if the stop release flag is 1 (NO), the process proceeds to step S18.

In step S18, the control device PLC determines whether the rotating plate 10 of the garbage loading device is in the stop position (one-cycle stop position) when the garbage loading operation is stopped. If the rotating plate 10 of the garbage loading device is in the one-cycle stop position (YES), the process proceeds to step S19, and the garbage loading operation of the garbage loading device is normally stopped. On the other hand, if the rotating plate 10 of the garbage loading device is not in the one-cycle stop position (NO), the process returns to step S11, and the process from step S11 onwards is executed again.

Next, the flow of control executed by the image processing unit 9 will be described with reference to the flowchart in FIG. 10. As shown in FIG. 10, in step T1 after starting, when the operator switches the ignition switch SWK from off to on, the power supply to the image processing unit 9 changes from off to on. In step T2, an initialization process (start-up process) of the image processing unit 9 is performed. At this time, the operation lamp 72 and the detection lamp 73 are turned off. In addition, the input port table recognition flag is reset to 0, and the recognition error warning lamp 81 and the camera angle abnormality warning lamp 82 are turned off.

This initialization process (start-up process) takes at least a few seconds. Until this initialization process is complete, i.e., during startup, the image processing unit 9 does not output a person safety signal, nor does it output an ON signal to the in-operation lamp 72, detection lamp 73, recognition error warning lamp 81, and camera angle abnormality warning lamp 82 (the image processing unit 9 controls the in-operation lamp 72, detection lamp 73, recognition error warning lamp 81, and camera angle abnormality warning lamp 82 so as not to operate).

If an operator turns on the PTO switch SWP while the image processing unit 9 is running, the control device PLC will be able to recognize that no personnel safety signal has been input from the image processing unit 9, and even if the operator presses the loading button 64 after turning on the PTO switch SWP, the control device PLC will control the garbage loading device not to operate based on the absence of a personnel safety signal.

In step T3, the central processing unit CPU of the image processing unit 9 determines whether the entire image processing unit 9 is operating normally. If the image processing unit 9 is operating normally (YES), the process proceeds to step T4, and if the image processing unit 9 is not operating normally (NO), the process proceeds to step T42. In steps T42 to T44, the image processing unit 9 does not turn on the operation lamp 72 and the detection lamp 73, but turns on the error indicator lamp provided on the board, and then proceeds to step T22.

Next, in step T4, the central processing unit CPU of the image processing unit 9 determines whether or not a reverse signal based on the driving operation of the vehicle has been input. The reverse signal is input to the image processing unit 9 via the current line K8 when the vehicle is reversed, and the determination of step T4 is made based on the presence or absence of this reverse signal. If a reverse signal has not been input (YES), the process proceeds to step T5, and if a reverse signal has been input (NO), the process proceeds to step T35.

Next, in step T5, the central processing unit CPU of the image processing unit 9 determines whether or not a loading line signal has been input. The loading line signal is input to the image processing unit 9 via the current line K10 when the PTO switch SWP is on and the changeover switch SW6 is switched to the loading side. The determination in step T5 is made based on the presence or absence of this loading line signal. Then, if a loading line signal has been input (YES), the process proceeds to step T6, and if a loading line signal has not been input (NO), the process returns to step T4 and makes the determinations in steps T4 and T5 again.

Next, in step T6, the central processing unit CPU of the image processing unit 9 judges whether the input port table 65 is in a horizontal state. This judgement is made based on the detection signal from the horizontal state detection switch 66a input via the current line K19. Then, if a signal is input from the horizontal state detection switch 66a and the input port table 65 is in a horizontal state (YES), the process proceeds to step T7, and if a signal is not input from the horizontal state detection switch 66a and the input port table 65 is not in a horizontal state (NO), the process proceeds to step T29. If the input port table 65 is in an upright position and not horizontal, the input port table recognition process described below cannot be performed, so a situation in which the input port table 65 is not in a horizontal state is excluded.

Next, in step T7, the central processing unit CPU of the image processing unit 9 turns on the operation lamp 72. Then, in step T8, the central processing unit CPU determines whether the input slot table recognition flag is 0 or not, and if the input slot table recognition flag is 0 (YES), the process proceeds to step T9. On the other hand, if the input slot table recognition flag is 1 (NO), the process proceeds to step T22.

Next, in step T9, the central processing unit CPU of the image processing unit 9 causes the image processing unit DSP to execute a slot table recognition process. Details of the slot table recognition process executed by the image processing unit DSP of the image processing unit 9 will be described with reference to the flowchart in FIG. 11.

First, in step T91 after starting, the image processing unit DSP performs binarization processing on the image data (input image data) captured by the camera 71 and input to the image processing unit 9. This binarization processing is, for example, a process in which the luminance value of each pixel in the input image data is set to a maximum luminance value when it is equal to or greater than a preset threshold value, and is set to a minimum luminance value when it is less than the threshold value. The generated binary image data is one in which much of the effects of noise and changes in the amount of light have been removed.

Next, in step T92, labeling processing is performed by the image processing unit DSP. This labeling processing is a process for dividing adjacent pixels in the binary image data into regions, for example, a process in which multiple pixels that have the same luminance value and are close to each other within a specified distance are regarded as one region. The labeling processing is performed on the entire image plane, and each region that has been divided into one region is extracted as an object image.

Next, in step T93, the previously set table recognition feature data (table recognition dictionary) is referred to, and it is determined whether or not there is an object image that satisfies the conditions of the table recognition feature data among the object images after the labeling process. The table recognition feature data is obtained by taking images of many types of input port tables 65 in advance and extracting features such as the size and shape of the input port table 65, and is stored in the memory M of the image processing unit 9. In this embodiment, the camera 71 is disposed above the garbage input port 4, and the vicinity of the garbage input port 4 below is photographed almost directly from above. Therefore, the input port table 65 is displayed in the image so that it is located (fitted) within the input port table detection area A3, as shown in an example in FIG. 12. Therefore, in step T93, the previously set table recognition feature data is referred to, and an object image that satisfies the conditions of the table recognition feature data is determined to be the input port table 65. The input port table detection area A3 is set, for example, to be approximately the same area as the above-mentioned loading person detection area, and is stored in the memory M. Specifically, the input table detection area A3 is a combination of a first detection area A11, which is set as a normal area when workers perform garbage loading work, and a second detection area A12, which is a no-entry area.

Returning to the flowchart of FIG. 10, in step T10, the central processing unit CPU of the image processing unit 9 determines whether or not the input port table 65 has been recognized by the input port table recognition process of step T9. In this case, it is determined whether or not an object image that satisfies the conditions of the table recognition feature data has been recognized in the input port table detection area A3. Then, if the input port table 65 has been recognized in the input port table detection area A3 (YES), the process proceeds to step T11, and if the input port table 65 has not been recognized in the input port table detection area A3 (NO), the process proceeds to step T31.

In step T11, the central processing unit CPU of the image processing unit 9 determines whether or not an angle storage switch signal has been input. This determination is made based on the signal from the camera angle adjustment switch SW8 input via the current line K18. If a signal has been input from the camera angle adjustment switch SW8 (YES), the process proceeds to step T25, where the camera angle adjustment mode is started. On the other hand, if a signal has not been input from the camera angle adjustment switch SW8 (NO), the process proceeds to step T12.

In step T25, the central processing unit CPU of the image processing unit 9 initializes the reference coordinate (Y0) of the rear end position of the insertion slot table 65. In step T26, the central processing unit CPU of the image processing unit 9 calculates the coordinate (Y0) of the rear end position of the image (object image) recognized as the insertion slot table 65 in the insertion slot table recognition process in step T9. In step T27, the central processing unit CPU of the image processing unit 9 stores the coordinate (Y0) of the rear end position of the insertion slot table 65 obtained in step T26 as the reference coordinate. In step T28, the central processing unit CPU of the image processing unit 9 ends the camera angle adjustment mode of steps T25 to T27, returns to step T9, and performs the insertion slot table recognition process again. Note that the coordinate of the rear end position of the insertion slot table 65 is the coordinate in the front-rear direction of the vehicle (Y coordinate). In addition, more specifically, the rear end position of the insertion slot table 65 at the center position in the vehicle width direction is used as the rear end position of the insertion slot table 65.

Then, in step T12, the central processing unit CPU of the image processing unit 9 calculates the coordinate (Y1) of the rear end position of the image (object image) recognized as the input port table 65 in the input port table recognition process of step T9. In step T13, the central processing unit CPU of the image processing unit 9 compares the coordinate (Y1) of the rear end position of the input port table 65 obtained in step T12 with the reference coordinate (Y0) obtained in the camera angle adjustment mode of steps T25 to T27 described above. If the two match (Y0 = Y1), proceed to step T13; if they do not match (Y0 ≠ Y1), proceed to step T32.

In this step T13, if the deviation between the coordinate (Y1) of the rear end position of the inlet table 65 and the reference coordinate (Y0) is within a range of a preset tolerance, it is possible to determine that the two match (Y0=Y1). On the other hand, if the deviation between the coordinate (Y1) of the rear end position of the inlet table 65 and the reference coordinate (Y0) exceeds a preset tolerance, it is possible to determine that the two do not match (Y0≠Y1). In this way, the shape of the inlet table 65 in the image taken by the camera 71 is learned in advance, and it is possible to recognize that the angle of the camera 71 has changed based on the fact that the reference coordinate (Y0) in the image of the camera 71 does not include the coordinate (Y1) of the rear end position of the inlet table 65. On the other hand, it is possible to recognize that the angle of the camera 71 has not changed based on the fact that the reference coordinate (Y0) in the image of the camera 71 includes the coordinate (Y1) of the rear end position of the inlet table 65.

Next, in step T14, the central processing unit CPU of the image processing unit 9 sets the inlet table recognition flag to 1. The inlet table recognition flag is set to 1 when the coordinate (Y1) of the rear end position of the inlet table 65 matches the reference coordinate (Y0) (Y0=Y1). When the inlet table recognition flag is set to 1, a negative judgment is made in step T8 unless the inlet table 65 is returned to the upright position, and therefore no inlet table recognition processing is performed thereafter. This is because if the inlet table 65 is in a horizontal position and the inlet table recognition processing is repeated during the garbage loading operation, the inlet table 65 may be blocked by the garbage being fed in, causing frequent recognition errors.

Then, in step T15, the central processing unit CPU of the image processing unit 9 determines that the angle of the camera 71 has not changed, and proceeds to step T16 without outputting an ON signal to the recognition error warning lamp 81 and the camera angle abnormality warning lamp 82.

Next, in step T16, the central processing unit CPU of the image processing unit 9 sets the feature data (dictionary data) used in the person recognition process as the loading feature data, and sets the detection area used in the person detection judgment as the loading person detection area. The loading feature data is referenced during the person recognition process (step T17) described later, and is stored in the memory M of the image processing unit 9. The loading feature data is obtained by taking images of many people's heads in advance and extracting their features such as size and shape. The features extracted as the loading feature data are mainly the head shape when the person is viewed from above. The loading person detection area is used during the person detection judgment, and is stored in the memory M of the image processing unit 9. As described above, the loading person detection area is divided into a first detection area A11 set as a normal area when the worker performs the garbage loading work, and a second detection area A12 as a no-entry area, and each area is stored in the memory M.

Next, in step T17, the central processing unit CPU of the image processing unit 9 causes the image processing unit DSP to execute person recognition processing. Details of the person recognition processing executed by the image processing unit DSP of the image processing unit 9 will be described with reference to the flowchart of FIG. 13. First, in step T171 after the start, the image processing unit DSP performs binarization processing on the image data (input image data) captured by the camera 71 and input to the image processing unit 9. This binarization processing is, for example, a process in which the luminance value of each pixel in the input image data is set to a maximum luminance value when it is equal to or greater than a preset threshold value, and is set to a minimum luminance value when it is less than the threshold value. The generated binary image data has most of the effects of noise and changes in light amount removed.

Next, in step T172, labeling processing is performed by the image processing unit DSP. This labeling processing is a process for dividing pixels that are close to each other in the binary image data into regions, for example, a process in which multiple pixels that have the same luminance value and are close to each other within a specified distance are regarded as one region. The labeling processing is performed on the entire image plane, and each region that has been divided into one region is extracted as an object image.

Then, in steps T173 to T175, the image processor DSP performs person identification processing on each object image detected in the first detection area A11 or the second detection area A12 described above. In this embodiment, the camera 71 is disposed above the garbage inlet 4, and the area near the garbage inlet 4 below is photographed from almost directly above. Therefore, the image shows a large image of the head of person H, as shown in an example in Figure 8, and also shows part of the face as seen from above. Therefore, in step T173, the loading feature data that has been set in advance is referenced, and an object image that satisfies the conditions of this loading feature data is provisionally determined to be the head of person H.

Next, in steps T174 and T175, the object image tentatively determined to be a head is discriminated from other object images. First, in step T174, a change in the position of the object image is detected by differential processing (processing to find the difference in luminance value for each pixel) of multiple image data input in time series from camera 71. This change in position, that is, the movement distance of the object image, is divided by the time required for that (the time interval for acquiring the image data) to calculate the movement speed of the object image.

Next, in step T175, it is determined whether the moving speed calculated in step T174 is equal to or lower than a preset threshold value. This threshold value is set in advance through experiments, etc., so that the moving speed of the head of the worker who puts the trash into the trash inlet 4 can be distinguished from the moving speed of the trash being put in. Then, if the calculated moving speed is higher than the threshold value, it is determined that the movement is too fast and is not the head of person H, a negative determination is made (NO), and the routine is terminated (END).

On the other hand, if it is determined in step T175 that the calculated moving speed is equal to or less than the threshold (YES), the object image is determined to be the head of person H (main determination), and the process proceeds to step T176, where a person detection signal is output.

Next, in step T177, it is determined whether the object image determined to be the head of person H is within the second detection area A12 described above. The determination in step T177 can be made based on whether the position coordinates of the pixels forming the outline of the area forming the object image are even partially included in the second detection area A12.

If it is determined that the object image identified as the head of person H is in the second detection area A12 (YES), the process proceeds to step T178, where a stop signal is output to the central processing unit CPU to stop the operation of the garbage loading device, and the routine ends (END). On the other hand, if it is determined that the object image is not in the second detection area A12 (NO), the stop signal is not output and the routine ends (END).

Returning to the flowchart of FIG. 10, in step T18, the central processing unit CPU of the image processing unit 9 determines whether or not a person has been detected in the first detection area A11 or the second detection area A12 by the person recognition process of step T17. At this time, the memory M of the image processing unit 9 is referenced to determine whether or not a person detection signal has been output. If a person detection signal has been output (YES), the process proceeds to step T19, and if a person detection signal has not been output (NO), the process proceeds to step T33.

Next, in step T19, the central processing unit CPU of the image processing unit 9 determines whether or not a person has entered the second detection area A12, which is a no-entry area, through the person recognition process of step T17. At this time, the memory M of the image processing unit 9 is referenced to determine whether or not a stop signal has been output. If a stop signal has been output (YES), the process proceeds to step T20, and if a stop signal has not been output (NO), the process proceeds to step T23.

The central processing unit CPU of the image processing unit 9 then outputs an ON signal for the detection lamp 73 in step T20, does not output a person safety signal to the control device PLC in step T21, and then proceeds to step T22. The central processing unit CPU also does not output an ON signal for the detection lamp 73 in step T33, outputs a person safety signal to the control device PLC in step T34, and then proceeds to step T22. The central processing unit CPU also outputs an ON signal for the detection lamp 73 in step T23, outputs a person safety signal to the control device PLC in step T24, and then proceeds to step T22.

If the image processing unit 9 is still powered on in step T22 (NO), the image processing unit 9 returns to step T3 and executes the processes from step T3 onwards again. On the other hand, if the image processing unit 9 is powered off in step T22 (YES), this routine is terminated (END).

If the determination in step T4 above indicates that a reverse signal has been input (NO), the image processing unit 9 does not output an ON signal for the operating lamp 72 in step T35, does not output a person safety signal to the control device PLC in step T36, and then proceeds to step T37.

Then, in step T37, the feature data (dictionary data) used in the person recognition process is set as the reverse feature data, and the detection area used in the person detection judgment is set as the third detection area A2 for reverse. The reverse feature data is referenced during the person recognition process (step T38) described later, and is stored in the memory M of the image processing unit 9. The reverse feature data is obtained by taking many images of the heads of people in advance and extracting features such as the size and shape of the head. The features extracted as the reverse feature data are mainly the head shape when the person is viewed from diagonally above and closer to the front than the loading feature data described above. The third detection area A2 is used during the person detection judgment, and is stored in the memory M of the image processing unit 9. As described above, the third detection area A2 includes the second detection area A12 and the first detection area A11 for loading, and the area behind them.

Next, in step T38, person recognition processing is performed by the image processing unit DSP. The person recognition processing in step T38 is substantially the same as the person recognition processing in step T17 described above (see FIG. 13), and includes binarization processing, labeling processing, person identification processing, and the like. Note that in the person identification processing, the retreat feature data set in step S37 is used, and an object image that satisfies the conditions of this retreat feature data is determined to be person H. Note that the recognition of person H is not limited to identifying the head shape, and it may also be possible to identify, for example, hands and feet.

Then, in step T39, the central processing unit CPU of the image processing unit 9 determines whether or not a person has been detected in the third detection area A2 by the person recognition process in step T38. At this time, the memory M of the image processing unit 9 is referenced to determine whether or not a person detection signal has been output. If a person detection signal has been output (YES), in step T40, the image processing unit 9 activates the buzzer 91 to output a retreat warning sound, and then proceeds to step T22. On the other hand, if a person detection signal has not been output (NO), in step T41, the image processing unit 9 does not activate the buzzer 91, and then proceeds to step T22.

Furthermore, if the judgment in step T6 above detects that the feed inlet table 65 is not in a horizontal state (NO), the central processing unit CPU of the image processing unit 9 does not output an ON signal for the in-operation lamp 72 in step T29, resets the feed inlet table recognition flag to 0 in step T30, and then proceeds to step T33. If it is detected that the feed inlet table 65 is not in a horizontal state, the in-operation lamp 72 and detection lamp 73 are turned off, and person recognition is disabled. However, even in this case, a person safety signal is output to the control device PLC, and garbage loading work is possible.

If the judgment in step T10 above indicates that the input port table 65 is not recognized within the input port table detection area A3 (NO), the central processing unit CPU of the image processing unit 9 outputs an ON signal to the recognition error warning lamp 81 in step T31, turning on the recognition error warning lamp 81, and then proceeds to step T33. When the recognition error warning lamp 81 turns on, the operator can recognize that the input port table 65 cannot be detected or that there is an abnormality in the imaging lens 71a of the camera 71. Note that once the recognition error warning lamp 81 turns on, it remains lit until the abnormality is resolved or the power to the image processing unit 9 is turned off (the ACC power is turned off).

If the coordinate (Y1) of the rear end position of the input port table 65 does not match the reference coordinate (Y0) (Y0 ≠ Y1) in the determination of step T13 described above, the central processing unit CPU of the image processing unit 9 outputs an ON signal to the camera angle abnormality warning lamp 82 in step T32 to turn on the camera angle abnormality warning lamp 82, and then proceeds to step T33. The lighting of the camera angle abnormality warning lamp 82 allows the operator to recognize that the mounting angle of the camera 71 has changed due to some cause (for example, a collision of an object with the camera 71, etc.). Note that once the camera angle abnormality warning lamp 82 is turned on, it will remain lit until the abnormality is resolved or the power of the image processing unit 9 is turned off (the ACC power is turned off).

As described above, in this embodiment, a control unit (image processing unit 9) is provided which determines whether the inlet table 65, which is an attachment part attached to the garbage inlet box 3 separately from the camera 71, has been detected in the inlet table detection area A3 near the garbage inlet 4 based on the image data captured (acquired) by the camera 71, and this control unit is configured to compare the reference coordinate (Y0) of the rear end position, which is the first position in the image of the inlet table 65 detected at a predetermined first timing, with the coordinate (Y1) of the rear end position, which is the second position in the image of the inlet table 65 detected at a predetermined second timing after the first timing, and output an abnormality if the deviation between the two exceeds an allowable value.

According to this embodiment, even if the mounting angle of the camera 71 at the upper rear of the garbage bin 3 has changed due to some cause (for example, a collision of an object with the camera 71, etc.), it is possible to easily recognize the change. In detail, at the first timing (step T26) and the second timing (step T12), the coordinates of the rear end position of the input port table 65 in the image recognized as the input port table 65 in the input port table recognition process (step T9) are calculated, and the reference coordinates (Y0; first position) of the rear end position of the input port table 65 at the first timing are compared with the coordinates (Y1; second position) of the rear end position of the input port table 65 at the second timing (step T13). Then, when the deviation between the two exceeds the allowable value, an ON signal is output to the camera angle abnormality warning lamp 82, and the camera angle abnormality warning lamp 82 is turned on (step T32). In this way, by detecting the change in the rear end position of the feed inlet table 65 based on the image data captured by the camera 71, it is possible to easily recognize that the mounting angle of the camera 71 has changed when performing garbage loading work, even if the mounting angle of the camera 71 at the upper rear of the garbage feed box 3 has changed.

In this embodiment, the attachment part is an inlet table 65 that is provided at the rear edge (lower edge) 4b of the garbage inlet 4 so as to be switchable between an upright state and a horizontal state. In this case, a horizontal state detection switch 66a is provided to detect that the inlet table 65 is in a horizontal state, and the above-mentioned first timing (step T26) or second timing (step T12) occurs when the horizontal state detection switch 66a detects that the inlet table 65 is in a horizontal state. As a result, when the inlet table 65 is in an upright state, the inlet table recognition process cannot be performed, so the inlet table recognition process is performed only when the horizontal state detection switch 66a detects that the inlet table 65 is in a horizontal state, and a change in the mounting angle of the camera 71 at the upper rear of the garbage inlet box 3 is detected.

In this embodiment, there is a PTO switch SWP, which is the main power source switch that turns the power source of the garbage loading device on and off, and turning on the PTO switch SWP (step T5) is set as the condition for the first timing or the second timing. As a result, since the garbage loading device is driven by turning on the PTO switch SWP, even if the mounting angle of the camera 71 at the upper rear of the garbage bin 3 has changed, it is possible to reliably recognize that the mounting angle has changed when performing garbage loading work.

In this embodiment, the image processing unit 9 as a control unit is configured to determine whether the rear end position of the inlet table 65 at the first timing is a reference coordinate (Y0) and whether there is a deviation of the coordinate (Y1) of the rear end position of the inlet table 65 at the second timing from this reference coordinate (Y0). Furthermore, the image processing unit 9 is connected to a camera angle adjustment switch SW8 for enabling the reference coordinate (Y0) to be changed. Since there are many different specifications for the garbage collection vehicle 100 and the mounting position of the camera 71 is not constant, the shape and position of the garbage inlet 4 reflected by the camera 71 fluctuates. For this reason, it is preferable to provide a camera angle adjustment switch SW8 and make the reference coordinate (Y0) adjustable for each vehicle, taking into account the mounting position of the camera 71, the shape and position of the garbage inlet 4, etc. It is preferable to set the tolerance value for each vehicle, taking into account the mounting position of the camera 71, the shape and position of the garbage inlet 4, etc.

-Other embodiments-
The embodiments disclosed herein are illustrative in all respects and are not intended to be limiting. The technical scope of the present invention is not interpreted solely by the above-described embodiments, but is defined by the claims. The technical scope of the present invention includes all modifications within the scope and meaning equivalent to the claims.

In the above embodiment, the attachment part for detecting the mounting angle of the camera 71 at the upper rear of the garbage bin 3 is the inlet table 65, and the change in the rear end position of this inlet table 65 is detected. However, this is not limited to this, and the mounting angle of the camera 71 may be detected using an attachment part other than the inlet table 65 attached to the garbage bin 3. Also, the change in the position other than the rear end position of the inlet table 65 may be detected. Note that, as long as the mounting angle of the camera 71 does not change, it does not have to be a particular part as long as the position of the camera 71 in the image is fixed. For example, the rear end position of the tailgate 5, the handle, the hopper side panel, etc. may be detected, or a marker painted somewhere on the rear of the garbage bin 3 may be detected.

In the above embodiment, a camera 71 is used as the image acquisition unit, but the image acquisition unit may be something other than a camera 71, such as a distance image sensor, a stereo camera, or a 3D-LIDAR, which is capable of acquiring images and measuring distances.

In the above embodiment, the first position (Y0) and the second position (Y1) of the rear end position of the inlet table 65 obtained at the first timing (step T26) and the second timing (step T12) were used, but the first position (Y0) and the second position (Y1) may be obtained at timings other than those mentioned above.

The above-mentioned areas for detecting people (first detection area A11, second detection area A12) and the inlet table detection area A3 are merely examples, and areas other than those mentioned above may be used. For example, the entire area forward of the rear edge 4b of the garbage inlet 4 may be set as the second detection area A12 (no-entry area). In this case, if the determination in step T177 is that the position coordinates of the pixels forming the outline of the area forming the above-mentioned object image are included forward of the rear edge 4b of the garbage inlet 4, it may be determined that an object image identified as a person has been detected in the second detection area A12.

In the above embodiment, the image processing control in the refuse collection vehicle 100 (see Figures 9 to 11 and 13) is shared and executed by the control device PLC and the image processing unit 9, but the image processing control in the refuse collection vehicle 100 may be executed by only a single control device. For example, the control device PLC may also be provided with the functions of the image processing unit 9, and the flowcharts in Figures 9 to 11 and 13 may be executed by only the control device PLC.

In the above embodiment, the operation lamp 72, detection lamp 73, recognition error warning lamp 81, and camera angle abnormality warning lamp 82 serving as notification units were electrically connected to the image processing unit 9, but these lamps (notification units) may also be connected to the control device PLC that controls the operation of the garbage loading device.

In the above embodiment, the present invention is described as being embodied as a garbage collection vehicle 100 equipped with a so-called rotary garbage loading device, and the main part of the garbage loading device is composed of a rotating plate 10 and a push plate 20. However, this is not limited to this, and the main part of the garbage loading device may be composed of a lifting plate and a push plate, and the structure is not particularly limited.

The present invention can be used in a garbage collection vehicle that includes a garbage loading device disposed inside a garbage bin and an image acquisition unit that is attached to the garbage bin and acquires images of the vicinity of the garbage bin's garbage inlet.

1 Chassis 2 Dust collection box 3 Dust input box 4 Dust input port 9 Image processing unit (control unit)
65 Inlet table (attachment part)
71 Camera (image acquisition unit)
81 Recognition error warning lamp 82 Camera angle abnormality warning lamp 100 Refuse collection vehicle A3 Feeding port table detection area (attachment parts detection area)

Claims (5)

A garbage collection vehicle including a garbage loading device disposed inside a garbage dump box and an image acquisition unit attached to the garbage dump box for acquiring an image of a vicinity of a garbage dump opening of the garbage dump box,
a control unit that determines whether or not a person is in a no-entry area near the garbage inlet during garbage loading based on the image acquired by the image acquisition unit, and determines whether or not an attachment part attached to the garbage inlet box is detected in an attachment part detection area near the garbage inlet separately from the image acquisition unit, thereby detecting the position of the attachment part;
a notification unit electrically connected to the control unit,
The control unit stops the operation of the garbage loading device when it is determined that a person has entered the no-entry area during garbage loading work,
Furthermore, the control unit is configured to compare a first position of the attachment part in the image detected at a predetermined first timing during garbage loading operation with a second position of the attachment part in the image detected at a predetermined second timing during garbage loading operation after the first timing, and to output a signal to notify the alarm unit of an abnormality if a deviation between the first position and the second position exceeds an allowable value. The refuse collection vehicle according to claim 1,
A refuse collection vehicle, characterized in that the attachment part is an inlet table that is provided at the lower edge of the refuse inlet and can be switched between an upright position and a horizontal position. The refuse collection vehicle according to claim 2,
A horizontal state detection sensor is provided to detect whether the input port table is in a horizontal state.
The refuse collection vehicle is configured such that the first timing condition is determined to be the horizontal state of the input table detected by the horizontal state detection sensor. The refuse collection vehicle according to claim 1 ,
A power source main switch for turning on and off the power source of the garbage loading device is provided,
A refuse collection vehicle characterized in that the first timing condition is determined to be when the power source main switch is turned on. A refuse collection vehicle according to any one of claims 1 to 4,
the control unit is configured to determine whether or not the second position is shifted from the reference value by using the first position as a reference value;
The refuse collection vehicle further comprises an adjustment switch connected to the control unit for enabling the reference value to be changed.

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