JP6887308B2 - Garbage truck and person recognition device equipped on it - Google Patents

Description

The present invention relates to a person recognition device equipped on a work vehicle so as to recognize a worker or the like in the vicinity of an article input port by an image processing technique.

Conventionally, for example, in a garbage truck (working vehicle), a dust loading device is installed in a dust loading box provided at the rear of the chassis, and dust thrown from a dust loading port into the dust loading box. It is designed to be scraped with a rotating plate or loading plate and loaded into the garbage storage box. In addition, in order to prevent workers who inject dust into the dust inlet from being inadvertently caught in the dust loading device, there are various monitoring systems that monitor people in the vicinity of the dust inlet. Proposed.

For example, in the surveillance system described in Patent Document 1, a camera for automatic person recognition as an imaging means is arranged in the upper rear part of the dust input box, and the lower dust input port and its surroundings are photographed. Then, if it is determined that a person has entered the preset prohibited area in the image taken by the camera while the dust loading device is operating, the operation of the dust loading device is stopped.

Japanese Patent No. 4283568

By the way, in recent years, it has been proposed that a garbage truck be equipped with a back camera for the driver to check the rear with his / her eyes. In this case, the back camera is usually placed in the upper rear part of the garbage truck. It will be installed and the lower dust inlet and its rear will be photographed. Therefore, even in the above-mentioned conventional example, it is conceivable to use the back camera as an imaging means for automatically recognizing a person by image processing.

However, the main purpose of the back camera is to check the rear, and since the optical axis of the image pickup lens is largely directed from vertically below to the rear (far from the vehicle), the dust inlet and the rear of the captured image are shown. Part of the distance from the person (distance in the front-back direction) will appear in the depth direction of the screen, and it is difficult to distinguish whether this person is near or far from the dust inlet. ..

That is, as shown in FIG. 12, when the optical axis A of the image pickup lens of the back camera C is largely directed backward and the inclination angle θ from the vertical downward direction becomes large, a dangerous area (hatching) above the dust inlet is large. When the person H approaches (indicated by), on the image plane, the distance D between the trailing edge of the dust inlet, that is, the boundary line B between the dangerous area and the safe area, and the head of the person H is actually This is because it looks much larger than the interval between.

If the camera for automatic person recognition of the surveillance system is configured by using the back camera (camera for checking the distance of the vehicle) in this way, there is a possibility that an error may occur in determining whether or not the person is in a dangerous area. If the optical axis of the image pickup lens is directed downward so as not to do so, the field of view to the rear is narrowed this time, which may cause a problem in checking the rear.

Focusing on this point, an object of the present invention is to use a vehicle distance confirmation camera as a camera for automatically recognizing a person by image processing, and to obtain a person from a predetermined area near the dust inlet from the image taken by the camera. It is to be able to more accurately determine whether or not the person is in the dangerous area).

The person recognition device of the present invention is equipped in a dust collecting vehicle provided with a dust input box on the chassis, and recognizes a person in the vicinity of a dust input port opened in the dust input box , and recognizes a person in the vicinity of the dust input box. A dust loading device is installed inside, a camera is arranged above the dust input port, image data taken by this camera is input, and a predetermined area near the dust input port is input in the image. It is equipped with an image processing device that determines whether or not there is a person in the area.

Then, a direction switching mechanism capable of switching the optical axis of the image pickup lens of the camera between a first direction oriented vertically downward toward a distance from the vehicle and a second direction closer to vertically downward than the first direction. The interlocking switching means is provided, and the interlocking switching means is provided to operate the direction switching mechanism in response to the opening and closing of the door of the dust input port. The interlocking switching means is imaged when the door is opened to start the operation of the dust loading device. The direction of the optical axis of the lens is switched to the second direction, while the direction of the optical axis of the imaging lens is switched to the first direction when the door is closed and the operation of the dust loading device is completed. It is characterized by that. Note that the fact that the direction of the optical axis of the imaging lens can be switched means that the direction can be switched with one action, and does not include a structure in which the direction of the camera changes if the bolt or the like is loosened.

In the person recognition device configured in this way, the optical axis of the image pickup lens of the camera arranged above the dust inlet is switched to the first direction directed to the distant vehicle, so that the field of view to the distant vehicle can be seen. Can be fully expanded. This is suitable for use as a vehicle distance confirmation camera. On the other hand, if the optical axis of the image pickup lens is switched to the second direction, which is close to the vertical downward direction, the depth direction of the captured image approaches the vertical direction, and the distance between the dust inlet and the person far away from the vehicle in this image plane is actually. Will approach the interval of.

This makes it possible for the image processing device to more accurately determine whether or not a person who has approached the dust inlet from a distance of the vehicle has invaded a dangerous area based on the image data. That is, by sharing the camera for image processing with the camera for confirming the distance of the vehicle and appropriately switching the direction of the optical axis, it becomes possible to more accurately determine whether or not the person is in a dangerous area.

Also, for example, when the worker opens the door of the dust inlet, the optical axis of the image pickup lens of the camera is directed in the second direction, and it is accurate whether or not the worker is in a dangerous area. You will be able to judge.

Also, when the dust loading device is operating for loading dust, the optical axis of the camera's imaging lens is directed in the second direction, and whether or not the operator is in a dangerous area. Can be accurately determined.

Further, as the configuration of the direction switching mechanism, it is possible to move only the image pickup lens without moving the camera itself, or to switch the direction of the optical axis by using, for example, a reflecting mirror, but it is preferable. Is to move the camera itself and configure it to change its orientation. In this way, it is only necessary to mount the camera so that its orientation can be switched, so that the cost increase is suppressed.

More specifically, as the interlocking switching means, an urging member that urges the camera so that the optical axis of the image pickup lens faces the first direction, and a displacement of the dust inlet to the open side of the camera are applied to the camera. A transmission member that transmits and changes the direction of the camera so that the optical axis faces the second direction against the urging force of the urging member may be provided. For example, a spring or the like can be used as the urging member, and a wire or a link can be used as the transmission member.

In this way, when the door of the dust inlet is closed, the camera is urged by the urging member so that the optical axis of the image pickup lens faces the first direction. Then, when the operator opens the door of the dust inlet, the displacement of this door is transmitted to the camera by the transmission member, and the direction is changed so that the optical axis of the image pickup lens is directed to the second direction. That is, the interlocking switching means can be mechanically configured, and the cost increase is suppressed.

Alternatively, when the direction switching mechanism is operated in response to the operation of the dust loading device, the interlocking switching means operates the actuator in response to the operation of the start switch of the dust loading device, and the direction of the optical axis of the imaging lens. The direction switching mechanism may be operated so as to switch (preferably the direction of the camera itself) from the first direction to the second direction. This will improve the accuracy of orientation switching.

The preferred layout of the camera that changes its orientation is that when the optical axis of the image pickup lens is oriented in the second direction, the center of the image pickup lens is the one edge of the dust inlet and the like in a plan view. It is located in the middle of the edge (including directly above one edge and the other edge). In this way, the image pickup lens looks down at the lower dust inlet from almost directly above, which is advantageous for accurately determining whether or not the person is in a dangerous area.

For that purpose, it is necessary to set the optical axis of the image pickup lens of the camera to be vertically downward as much as possible when it is directed in the second direction, for example, to pass through the dust inlet in a lateral view. preferable. In particular, by setting so that the optical axis passes through the edge of the dust inlet, the edge of the center dust inlet of the captured image, in other words safe area and appears as a boundary line between the hazardous area There is also an advantage that it is not easily affected by the distortion of the optical system.

From a different point of view, the present invention is a garbage truck equipped with the above-mentioned person recognition device. That is, if it is determined that the person is in a predetermined area in the pre-Symbol image processing apparatus, operation of the dust loading device is adapted to be stopped by the emergency stop device.

According to the person recognition device for a work vehicle according to the present invention, the optical axis of the image pickup lens of the camera arranged above the article input port is directed from vertically downward to the distance of the vehicle so as to be suitable as a camera for confirming the distance of the vehicle. Since it is possible to switch between the first direction and the second direction, which is closer to the vertical downward direction, a person can move to the vicinity of the article input port based on the image taken by the camera shared with the vehicle distance confirmation camera. It becomes possible to more accurately determine whether or not the user is in a predetermined area.

It is a side view which shows the garbage truck as a work vehicle which concerns on embodiment of this invention. It is explanatory drawing of the dust loading device equipped in the garbage truck of FIG. It is a hydraulic circuit diagram of the dust loading device of the garbage truck of FIG. It is the schematic which shows the control device of the garbage truck of FIG. 1 and the input / output state thereof. It is explanatory drawing which shows the schematic structure of the person recognition apparatus equipped in the garbage truck of FIG. It is a flowchart which shows an example of an image processing routine. It is explanatory drawing which shows an example of the image taken by a camera. It is a perspective view which shows the installation state of a camera enlarged from the rear. It is explanatory drawing of the structure which switches the direction of a camera in conjunction with the rise of a tailgate, and shows the time when a camera is in a normal position. FIG. 9 is a view corresponding to FIG. 9 showing when the camera is in the monitoring position. FIG. 8 is a view corresponding to FIG. 8 for another embodiment in which the direction of the camera is switched by a geared motor. It is a figure corresponding to FIG. 5 which shows the layout of the camera in the person recognition apparatus of the conventional example.

Hereinafter, embodiments in which the present invention is applied to a rotary garbage truck will be described with reference to the drawings. In the following description, for convenience, the front, rear, left, and right of the garbage truck may be simply referred to as front, back, left, and right.

FIG. 1 shows a garbage truck 100 as a work vehicle equipped with a person recognition device according to an embodiment of the present invention, and a dust storage box 2 and a dust input box 3 as a packing box are placed on the chassis 1 thereof. It is provided. The opening at the rear of the dust storage box 2 and the opening at the front of the dust storage box 3 are communicated with each other. Further, the dust input box 3 is pivotally supported by a pivot axis 3a in the left-right direction provided on the upper portion thereof, and is tilted by a pair of left-right tilting cylinders (not shown).

Further, a rectangular dust input port 4 (see also FIG. 7) for charging dust is opened at a lower portion on the back surface of the dust input box 3, and can be raised and lowered so as to open and close it. A tailgate 5 (door) is provided. That is, as shown in an enlarged manner in FIG. 2, guide rails 51 are provided along the left and right side edges of the dust inlet 4, and the rollers 52 provided on the left and right sides of the tailgate 5 are guide rails. It is designed to move along 51.

Two handles 53 (shown only in FIG. 2) gripped by the operator to raise and lower the tailgate 5 are provided on the lower side of the tailgate 5 side by side. In the present embodiment, there is an upper cover 31 of the dust input box 3 above the dust input port 4, and the tailgate 5 that has risen to the highest position is large except for the portion where the handle 53 is arranged. The portion is hidden behind the upper cover 31.

In the example shown in FIGS. 1 and 2, the upper cover 31 has a stepped shape in which the front half portion protrudes greatly upward, and the latter half portion is inclined so as to be lower toward the rear while being gently curved. The camera 7 is arranged so as to photograph the vicinity of the slot 4 and the rear thereof. A switch box 6 is provided on the left side of the dust inlet 4 in which switches for operations such as operation of the dust loading device are arranged side by side.

Then, as shown in FIG. 2, the inside of the dust loading box 3 is equipped with a dust loading device as a working device for loading the thrown dust into the dust storage box 2. The dust loading device of the present embodiment is a so-called rotary type in which dust is scraped up by the rotation of the rotating plate 10 and pushed into the dust storage box 2 by the pushing plate 20. That is, first, the rotating shaft 11 is erected in the lower part of the dust input box 3 so as to extend in the width direction thereof, and the base end side of the rotating plate 10 is fixed to the rotating shaft 11.

In the illustrated example, a hydraulic motor 13 capable of forward / reverse rotation is connected to the end of the rotating shaft 11 via a speed reduction mechanism 12. Therefore, the rotation of the hydraulic motor 13 is torqued up by the speed reduction mechanism 12 and transmitted to the rotating shaft 11, and the rotating plate 10 is rotated integrally with the rotating shaft 11, so that the tip portion thereof has a substantially semicircular cross section. It comes to move in the front-rear direction along the bottom wall of the dust input box 3 formed in.

On the other hand, the push-in plate 20 is provided above the rotary plate 10 over the entire width direction of the dust input box 3, and can swing in the front-rear direction around the left-right swing shaft 21 provided above the push-in plate 20. Is supported by. Further, the push plate 20 is provided with an extension portion 22 extending upward from the swing shaft 21, and a push cylinder 24 is erected between the extension portion 22 and the support pin 23 in front of the extension portion 22. The push-in plate 20 is swung in the front-rear direction by the expansion / contraction operation.

That is, as shown by the solid line in FIG. 2, when the pushing plate 20 is at the position where it swings most toward the dust storage box 2 (advance limit position), the rotating plate 10 moves upward without interfering with the pushing plate 20. The push-in plate 20 swings toward the dust input port 4 side after this. Then, even after the push-in plate 20 swings most toward the dust inlet 4 side and reaches the retreat limit position shown by the virtual line in FIG. 2, the rotation of the rotating plate 10 is continued.

The rotating plate 10 that rotates in this way scrapes the dust toward the dust storage box 2 side, and temporarily stops at the set stop position extending to the front dust storage box 2 side as shown by the solid line in FIG. Then, the push plate 20 swings toward the dust storage box 2 and pushes the dust on the rotating plate 10 into the dust storage box 2. Then, when the push-in plate 20 reaches the above-mentioned advance limit position again, the rotating plate 10 will rotate upward again.

By repeating the rotation of the rotating plate 10 and the swinging of the pushing plate 20 in synchronization with each other in this way, the dust thrown into the dust loading box 3 is continuously loaded into the dust storage box 2 (hereinafter, dust stacking). It is called a built-in operation). The configuration of the hydraulic circuit and the electronic control device (control system) for operating the rotary plate 10 and the push plate 20 in this way will be described below, but for that purpose, the rotary plate 10 and the push plate 10 are inside the dust input box 3. Switches LS1 to LS5 for detecting the position of the plate 20 are provided.

That is, as shown in FIG. 2, the switches LS1 and LS2, which are turned on when the push plate 20 is in the forward limit position or the reverse limit position, and the switches LS1 and LS2, which are turned on when the rotary plate 10 is in the set stop position, are turned on. The switch LS3, the switch LS4 that is turned on when the rotating plate 10 is rotated by a predetermined angle in the positive direction (clockwise in FIG. 1) from the set stop position, and the switch LS5 that is turned on when the rotating plate 10 is further rotated by a predetermined angle. Is provided.

The switches LS1 and LS2 are designed to detect dogs (not shown) provided at the end of the swing shaft 21 of the push plate 20, and the switches LS3 to LS5 are the rotary shafts 11 of the rotary plate 10. A dog (not shown) provided at the end is detected. Further, as these switches LS1 to LS5, for example, a photoelectric switch, a proximity switch, or the like can be used.

In the switches LS4 and LS5, as shown by hatching in FIG. 2, the rotating plate 10 descends from directly below the front edge portion 4a of the dust input port 4 while rotating backward, and the dust input port 4 The angle range Z until it is closest to the trailing edge portion 4b is detected. In this angle range Z, there is a risk that the rotating plate 10 may involve a part of the operator's body, so it will be referred to as a dangerous angle range Z below.

Further, as shown in FIGS. 1 and 2, emergency stop buttons 60 and 61 for stopping the operation of the dust loading device, an emergency stop plate 62, and the like are arranged in the vicinity of the dust input port 4. .. As shown in FIG. 1, an emergency stop button 60 is arranged in the switch box 6 on the left side of the dust inlet 4, and as shown by a broken line in FIG. 2, an emergency stop button 61 is provided on the right side of the dust inlet 4. It is arranged. The emergency stop plate 62 is arranged below the dust inlet 4 so as to turn on / off the switch SW3.

-Control system for dust loading device-
Next, with reference to FIGS. 3 and 4, a control system for operating the dust loading device as described above will be described. This control system consists of a hydraulic circuit that controls the hydraulic pressure supplied to the hydraulic motor 13 and the push cylinder 24 of the dust loading device, and a control device that outputs control signals to the electromagnetic control valves V1 and V2 provided in the hydraulic circuit. It is equipped with a PLC (Programmable Logic Controller).

First, the hydraulic circuit will be described with reference to FIG. 3. This hydraulic circuit controls the hydraulic pump P, the oil reservoir T, the electromagnetic control valve V1 for controlling the push cylinder 24, and the hydraulic motor 13. The electromagnetic control valve V2 of the above is provided. Although not shown, the driving force of the engine is transmitted to the hydraulic pump P via the PTO (power take-off).

As an example, the electromagnetic control valves V1 and V2 are each composed of an electromagnetic direction switching valve having 6 ports and 3 positions. When the solenoid SOLa is excited, the electromagnetic control valve V1 switches to the first communication position (upper position in the figure) and supplies hydraulic oil from the hydraulic pump P to the rod-side oil chambers of the pair of push cylinders 24. When the solenoid SOLb is excited, it switches to the second communication position (lower position in the figure) and supplies hydraulic oil to the oil chamber on the head side.

When the hydraulic oil is supplied from the electromagnetic control valve V1 to the oil chamber on the head side, the pair of push cylinders 24 are extended and the push plate 20 is swung forward. On the other hand, when the hydraulic oil is supplied to the rod-side oil chamber, the pair of push cylinders 24 contract and cause the push plate 20 to swing rearward. Further, when neither of the solenoids SOLa and SOLb is excited, the electromagnetic control valve V1 returns to the neutral position (center position in the figure).

On the other hand, when the solenoid SOLc is excited, the electromagnetic control valve V2 switches to the first communication position (the lower position in the figure), supplies hydraulic oil to the oil chamber on the forward rotation side of the hydraulic motor 13, and the hydraulic motor 13 Is operated in the normal direction. On the other hand, when the solenoid SOLd is excited, the electromagnetic control valve V2 switches to the second communication position (upper position in the figure), supplies hydraulic oil to the oil chamber on the reversing side of the hydraulic motor 13, and reverses the hydraulic motor 13. Activate.

Further, when neither of the solenoids SOLc and SOLd is excited, the electromagnetic control valve V2 returns to the neutral position (center position in the figure). When both the electromagnetic control valves V1 and V2 are in the neutral position, the hydraulic oil returns to the oil reservoir T. In the illustrated hydraulic circuit, reference numeral V3 is a check valve, and reference numeral V4 is a relief valve for setting an upper limit of the discharge pressure of the hydraulic pump P.

Next, the input / output state of the signal in the control device PLC will be described with reference to FIG. First, the power supply to the control device PLC is performed by the battery BT shown in the upper left of the figure. An energizing line K2 is connected between the battery BT and the ground line K1 on the right side of the figure so as to extend to the left and right at the top of the figure. Here, the key switch SWK and PTO switch of the garbage truck 100 are connected. A SWP, a relay coil CR1 and the like are provided.

Further, the upstream end of the energization line K3 is connected so as to branch off from the energization line K2 between the key switch SWK and the battery BT, and the signal power supply unit (signal power supply unit) of the control device PLC is connected via the energization line K3. Power is supplied to (not shown). That is, the contact cr1 of the relay coil CR1 is interposed on the upstream side (the side close to the battery BT) of the energizing line K3, and when the relay coil CR1 is turned on, the contact cr1 is closed and the energizing line K3 is energized. Will come to do.

This energizing line K3 is always energized during the dust loading operation of the dust loading device, and corresponds to the operation of the emergency stop buttons 60 and 61 and the emergency stop plate 62 described above with reference to FIG. Switches SW1 to SW3 that are opened and closed are interposed. When the energization is cut off by these switches SW1 to SW3, the operation of the control device PLC is stopped, so that the operation of the dust loading device is stopped. An image processing unit 8 is also provided in the energizing line K3, which will be described in detail later.

Further, as shown on the left side of FIG. 4, the upstream ends of the plurality of branch lines are connected so as to branch from the energization line K3 on the downstream side (far side from the battery BT) of the contact cr1. The switches LS1 to LS5 described above are interposed in each of these branch lines with reference to FIG. Based on the signals from these switches LS1 to LS5, the positions of the rotating plate 10 and the pushing plate 20 of the dust loading device, that is, the operating status is detected.

In addition to the above switches LS1 to LS5, on the input side to the control device PLC, although not shown, a start / stop switch for the dust loading device, a single-acting or continuous selection switch for the dust loading operation, and a dust stacking operation. A switch for selecting a loading operation and a dust discharging operation, a switch for operating the rotating plate 10 and the pushing plate 20 independently, a switch for tilting and opening the dust input box 3 and the like are also connected.

While various switches are connected to the input side as described above, solenoids SOLa to SOLd of the electromagnetic control valves V1 and V2 are connected to the output side (right side of FIG. 4) of the control device PLC. Then, the control device PLC sets the corresponding solenoids SOLa to SOLd in order to operate the hydraulic motor 13 and the push cylinder 24 according to a preset procedure based on the signals input from the switches SW1 to SW3, LS1 to LS5 and the like. It is programmed to output.

That is, for example, when the dust loading device operates the dust loading operation, both the key switch SWK and the PTO switch SWP on the energizing line K2 are closed and the relay coil CR1 is energized. As a result, the contact cr1 of the relay coil CR1 is closed, so that the control device PLC becomes operable by being energized by the energization line K3, and the control signal is output to the solenoids SOLa to SOLd as appropriate. ..

Upon receiving this control signal, the solenoids SOLa to SOLd are excited, and the positions of the electromagnetic control valves V1 and V2 are appropriately switched, so that the hydraulic motor 13, the push cylinder 24, and the like are supplied with hydraulic pressure. As a result, the hydraulic motor 13, the push cylinder 24, and the like operate, respectively, and as described above with reference to FIG. 2, the rotation of the rotary plate 10 and the swing of the push plate 20 are repeated in synchronization with each other.

Specifically, first, as shown by the solid line in FIG. 2, the push plate 20 is in the forward limit position and the on signal is output from the switch LS1, and the rotary plate 10 is in the set stop position and is also on from the switch LS3. When the signals are output, the control device PLC that receives these signals outputs the control signals, the electromagnetic control valve V2 is switched to the first communication position, and the hydraulic motor 13 starts the forward rotation operation. As a result, the rotating plate 10 starts to rotate upward.

Then, when a predetermined period elapses, a control signal is output from the control device PLC to the solenoid SOLa of the electromagnetic control valve V1, the electromagnetic control valve V1 is switched to the first communication position, and the push cylinder 24 starts the contraction operation. As a result, the push-in plate 20 swings toward the rear dust input port 4, and when the push-in plate 20 reaches the retreat limit position, an ON signal is output from the switch LS2.

In response to this, the control device PLC stops the output of the control signal to the solenoid SOLa, so that the electromagnetic control valve V1 returns to the neutral position and the swing of the push plate 20 is stopped. Further, while the push-in plate 20 is swinging in this way, the rotation of the rotating plate 10 continues, and the dust is scraped into the dust storage box 2 side, and the push-in plate 20 that rotates in this way The setting stop position is reached, and an on signal is output from the switch LS3.

In response to this, the control device PLC stops the output of the control signal to the solenoid SOLc of the electromagnetic control valve V2, so that the electromagnetic control valve V2 returns to the neutral position and the rotation of the hydraulic motor 13 is stopped. Further, the control device PLC outputs a control signal to the solenoid SOLb of the electromagnetic control valve V1, the electromagnetic control valve V1 is switched to the second communication position, and the push cylinder 24 starts the extension operation, whereby the push plate 20 Begins to swing forward.

In this way, the push plate 20 swinging toward the front dust storage box 2 pushes the dust on the rotating plate 10 into the dust storage box 2, and when the forward limit position is reached, the on signal is output from the switch LS1. In response to this, the control device PLC stops the output of the control signal to the solenoid SOLb, so that the electromagnetic control valve V1 returns to the neutral position and the push cylinder 24 is extended, that is, the push plate 20 is shaken forward. The movement stops.

-Person recognition device and emergency stop device-
By the way, when the dust loading device is performing the dust loading operation as described above, the operator who is loading the dust into the dust loading port 4 may be inadvertently caught in the rotating plate 10 or the like. Therefore, in the garbage truck 100 of the present embodiment, the camera 7 is arranged so as to photograph the vicinity of the dust input port 4, and it is determined by image processing that a person is present in a predetermined area in the vicinity of the dust input port 4. If so, the operation of the dust loading device is immediately stopped.

That is, in addition to appearing in FIGS. 1 and 2 above, as shown in FIG. 5, a camera 7 is arranged above the upper cover 31 on the back surface of the dust input box 3, that is, the dust input port 4, and is below. The vicinity of the dust inlet 4 is photographed. This camera 7 is also used as a back camera for the driver of the garbage truck 100 to check the rear (far away from the vehicle), and although not shown, an image taken by the camera 7 around the driver's seat is not shown. A monitor is provided to display.

In addition to being displayed on the monitor in this way, the image data captured by the camera 7 is an image processing unit 8 (an image processing device, for example, arranged around the driver's seat as shown by a broken line in FIG. 1). Will be sent to. Then, the object image determined to be the person H in this image is a dangerous area between the front edge portion 4a and the trailing edge portion 4b of the dust input port 4 (the predetermined area, which is hatched in FIG. 5). It is determined whether or not you are in (shown).

Here, as described above, when the dust loading device is loaded, both the key switch SWK and the PTO switch SWP are closed, and the control device PLC is energized by the energizing line K3. Then, as shown in FIG. 4, an image processing unit 8 is interposed in the middle of the energizing line K3, and if it is determined that the person H is in the dangerous area as described above, the control device PLC is connected. It is designed to cut off the power supply.

First, a method of recognizing a person by image processing will be described below. As schematically shown in FIG. 5, the image processing unit 8 includes a central processing unit CPU and a camera that execute a predetermined program to perform various controls. Image processing unit DSP that inputs image data from 7 and performs the following known image processing, memory M that stores data used in those central processing unit CPU and image processing unit DSP, central processing unit CPU A relay switch SW4 or the like that is opened / closed in response to the command of is provided.

Although not shown, the image processing unit 8 is also provided with a buffer for temporarily storing various data, a camera control circuit for controlling the camera 7 in response to a command from the central processing unit CPU, and the like. Further, in the present embodiment, the image processing unit 8 is provided with an image output unit VOP (video output) that displays the result of image processing as well as the data of the image taken by the camera 7.

-Image processing routine-
The image processing unit DSP is a general integrated circuit that performs known image processing logic at high speed. For example, binarization processing of input image data and each pixel close to each other in the binarized image data. Labeling process that makes the area of the object image, person identification process that identifies that the area of the object image aread by labeling is a person image, and determination of whether the position of the object image identified as the person image is a dangerous area. Performs the person position determination process.

Specifically, the image processing routine will be described with reference to the flowchart of FIG. 6. First, the binarization processing is performed in step S1 after the start. This is, for example, a process in which the maximum luminance value is set when the luminance value for each pixel of the input image data is equal to or more than a preset threshold value, and the minimum luminance value is set when the luminance value is less than the threshold value. The generated binarized image data is obtained by removing most of the effects of noise and changes in the amount of light.

Next, in step S2, a labeling process is performed. This is to regionize pixels that are close to each other in the binarized image data. For example, it is a process that considers a plurality of pixels that belong to the same luminance value and are close to each other within a predetermined distance as one region. .. The labeling process is performed on the entire image plane, and each area is recognized as an object image.

Then, in the following steps S3 to S5, the person identification process for each of the object images is performed. In the present embodiment, as described above with reference to FIG. 5, the camera 7 is arranged above the dust inlet 4, and the vicinity of the dust inlet 4 below is photographed. Therefore, in the image, the head of the person H is displayed in a large size as shown by an example in FIG. 7, and a part of the face viewed from above is also displayed. That is, the image data also includes information on the face of the person H.

Therefore, first, in step S3, preset feature data of the head (including the face), that is, data indicating, for example, the size and shape of the head, the state of the hair, etc. are referred to, and the condition of this feature data is satisfied. Such an object image is tentatively determined to be the head of the person H. The feature data is obtained by taking images of the heads (including faces) of many people in advance and extracting features such as their size and shape, and is stored in the memory M of the image processing unit 8. ing.

In steps S4 and S5, the process of identifying the object image determined to be the "temporary head" from other object images is performed. First, in step S4, a change in the position of the object image is detected by a difference process (a process of obtaining the difference in the brightness value for each pixel) of a plurality of image data input from the camera 7 in time series. Then, this change in position, that is, the moving distance of the object image, is divided by the time required for it (the time interval for acquiring the image data) to calculate the moving speed of the object image.

Then, in step S5, it is determined whether or not the calculated movement speed is equal to or less than the preset threshold value. This threshold value is set in advance by an experiment or the like so that the moving speed of the head of the worker who throws the dust into the dust throwing port 4 and the moving speed of the thrown dust can be distinguished. Therefore, if the calculated movement speed is higher than the threshold value, it is determined that the movement speed is not the head of the person H because the movement is too fast, a negative determination is made, and the (NO) routine is terminated (end).

On the other hand, if it is determined affirmatively that the moving speed is equal to or less than the threshold value in step S5 (YES), the object image is identified as the head of the person H and the process proceeds to step S6, and the object image is preset. Determine if you are in a dangerous area. This can be determined by whether or not the position coordinates of the pixels forming the outer shape of the region forming the object image are in front of the boundary line B (rear edge portion 4b of the dust inlet 4) of the dangerous area.

Therefore, if it is determined affirmatively that the object image identified as the head of the person H is in the dangerous area (YES), the process proceeds to step S7 to the central processing unit CPU in order to stop the operation of the dust loading device. Outputs a stop signal and ends the image processing routine (end). On the other hand, if it is negatively determined that the object image is not in the dangerous area (NO), the image processing routine is terminated without outputting the stop signal (end).

When a stop signal is emitted from the image processing unit DSP, the central processing unit CPU that receives the stop signal opens the relay switch SW4. That is, by energizing a relay coil (not shown) to open the contact of the switch, energization of the control device PLC by the energization line K3 is cut off. As a result, the operation of the control device PLC is forcibly stopped, so that even if there is some abnormality in the control device PLC, the energization of all the solenoids SOLa to SOLd of the electromagnetic control valves V1 and V2 is stopped. Become.

Therefore, all the electromagnetic control valves V1 and V2 in the first communication position or the second communication position return to the neutral position, and as a result, the operation of the hydraulic motor 13 and the push cylinder 24 is immediately stopped. As described above, in the present embodiment, the central processing unit CPU of the image processing unit 8 and the relay switch SW4 constitute an emergency stop device for stopping the operation of the dust loading device.

-Camera orientation switching-
Next, the structure for switching the orientation of the camera 7 described above will be described in detail. In the present embodiment, in step S6 of the flow of FIG. 6, the position coordinates of the pixels forming the outer shape of the object image identified as the head of the person H have the boundary line B (the trailing edge portion 4b of the dust input port 4). It is determined whether or not the object is in a dangerous area beyond the limit, and in order to make this determination accurately, it is desirable that the camera 7 shoots the dust inlet 4 from directly above as much as possible.

However, when a back camera is used as the camera 7, as shown in FIG. 12, the back camera C is usually arranged at an angle so as to widen the field of view to the rear, and the optical axis A of the image pickup lens is vertically downward. It is largely turned to the rear (far away from the vehicle). Therefore, in the image taken by the back camera C, it is difficult to accurately detect the distance D between the trailing edge portion (boundary line B) of the dust inlet and the person H behind it on the image plane.

That is, as shown in FIG. 12, when the optical axis A of the image pickup lens is largely directed to the rear and the inclination angle θ from the vertical downward direction becomes large, a dangerous area (hatched) above the dust inlet as shown in the figure. When the person H approaches (shown), the distance D between the trailing edge of the dust inlet (boundary line B) and the head of the person H appears to be considerably larger than the actual distance on the image plane. Because.

If the back camera C is used as it is and image processing is performed based on the image data in this way, an error may occur in determining whether or not a worker or the like (person H) is in a dangerous area. .. On the other hand, if the optical axis A of the image pickup lens 70 is brought closer to the vertical downward direction so as not to do so, the field of view to the rear is narrowed this time, which may cause a problem in use as a back camera.

Therefore, in the present embodiment, the orientation of the camera 7 can be changed, and the optical axis A of the image pickup lens 70 has a normal position oriented diagonally backward (first direction) like a normal back camera, and more than this. The structure is such that the camera switches to a monitoring position that is oriented in the second direction, which is close to vertical downward. Then, when an operator or the like opens the tailgate 5 of the dust inlet 4, the camera 7 is switched to the monitoring position in conjunction with this.

The installation state of the camera 7 will be described in detail. As shown in FIGS. 8 and 9, a support member 71 is fixed to the upper cover 31 of the dust input box 3, and a camera 7 is attached to the support member 71. The support member 71 is formed by, for example, press-molding an iron plate and then bending it, and connects the rectangular base 71a, the trapezoidal side wall portions 71b and 71c that rise from both the left and right sides thereof and extend upward, and the upper ends thereof to the left and right. It is provided with an extending rectangular eaves portion 71d.

The base 71a is overlapped on the upper cover 31 and fastened by bolts or the like (not shown), and a long slit 71e in the front-rear direction is provided near the center thereof, and a wire 75 is provided as described later. It has been inserted. Further, the side wall portions 71b and 71c rising from the left and right sides of the base 71a each have a trapezoidal frame shape in which two front and rear stays and two upper and lower stays are integrated.

The upper portions of the left and right side wall portions 71b and 71c (that is, the upper stay portion) are gently continuous with the curved portions formed on the left and right sides of the eaves portion 71d, respectively. Further, round holes are formed through the upper portions of the side wall portions 71b and 71c, respectively, and support pins 72 protruding from the portion on the base end side of the camera 7 to the left and right sides are inserted. As a result, the camera 7 is supported so that its tip side (the side of the image pickup lens 70) can be swung in the vertical direction.

Further, a tension coil spring 73 (a urging member) is provided so as to urge the tip end side of the camera 7 which can swing in the vertical direction upward. That is, as shown in FIG. 8, connecting pins 74 are attached to the lower part of the camera 7 so that the left and right ends project outward, respectively, and both ends (even one end). The lower end of the tension coil spring 73 is locked to each of the good).

The upper ends of these tension coil springs 73 are locked to the notches provided in the upper portions of the side wall portions 71b and 71c of the support member 71 (next to the round hole through which the support pin 72 is inserted in the example of FIG. 8). The tension coil spring 73 pulls up the tip side of the camera 7 by its elastic force. As an example, when the tension coil spring 73 receives the weight of the tip end side of the camera 7 and is slightly stretched, the tilt angle θ of the optical axis A of the image pickup lens 70 from the vertical downward direction is about 35 to 45 °.

On the other hand, one end of the wire 75 (transmission member) is connected to the left and right intermediate portions of the connecting pin 74 so that the displacement of the tailgate 5 toward the opening side is transmitted to the camera 7 as described below. It has become. When pulled downward by the wire 75, the camera 7 swings downward against the elastic force of the tension coil spring 73, and the optical axis A of the image pickup lens 70 approaches vertically downward.

More specifically, as shown in FIG. 9, the wire 75 extends diagonally forward downward from the connecting pin 74 at the lower part of the camera 7, passes through the slit 71e of the base 71a of the support member 71, and then is wound around the pulley 76 to orient the wire 75. It has changed and extends diagonally upward and forward. The pulley 76 is rotatably attached to a rectangular piece portion 71f projecting from the back side of the base 71a, and is located on the back side of the upper cover 31 of the dust input box 3.

Then, the other end side portion of the wire 75 extending diagonally upward from the pulley 76 along the back side of the upper cover 31 is the upper cover 31 as shown in the upper left in FIG. It is wound around a pulley 77 arranged near the uppermost portion on the back side of the wire, and is turned downward again. The pulley 77 is rotatably attached to the upper branch 78a of the bracket 78 having two upper and lower branches 78a and 78b.

As shown in FIG. 9, the bracket 78 is attached to, for example, the rib on the back side of the upper cover 31, and the upper and lower branch portions 78a and 78b are arranged so as to extend rearward, respectively. Then, the other end of the wire 75, which is wound around the pulley 77 and extends downward as described above, is connected to the lower branch portion 78b. Therefore, the wire 75 extends linearly between the upper branch portion 78a (pulley 77) of the bracket 78 and the lower branch portion 78b (hereinafter, this portion is referred to as an extension portion).

As described above, the direction of the camera 7, that is, the image pickup lens 70, depends on the length of the wire 75 from the lower part of the camera 7 (connecting pin 74) to the lower branch portion 78b of the bracket 78 through the two pulleys 76 and 77. The direction of the optical axis A will be determined. In the present embodiment, the length of the wire 75 is set so that the tension coil spring 73 that pulls up the tip side of the camera 7 extends slightly more than the state that supports the weight of the tip side of the camera 7.

In this way, the elastic force (tensile force) of the tension coil spring 73, which is increased by such a slight extension, and the initial tension generated in the wire 75 are balanced, and the orientation of the camera 7 is maintained. The position of the camera 7 at this time is the normal position, and the optical axis A of the image pickup lens 70 is in the first direction (for example, θ = 30 to 35 °) turned rearward like a general back camera. ).

In this way, at the normal position of the camera 7 in which the optical axis A of the image pickup lens 70 is turned to the rear, the field of view is greatly expanded to the rear, so that it is suitable for use as a back camera. At this time, the tailgate 5 of the dust inlet 4 is closed, and as described above, on the other end side of the wire 75, the wire 75 is stretched between the two upper and lower branches 78a and 78b of the bracket 78. Extends linearly.

Then, for example, when the operator grabs the handle 53 and pulls up the tailgate 5 to throw in the dust, the camera 7 is pulled up by the wire 75 when it rises to the highest position and the dust throwing port 4 is fully opened. Is pulled and swings downward against the elastic force of the tension coil spring 73. As a result, the camera 7 switches to the monitoring position, and the optical axis A of the image pickup lens 70 faces the second direction (for example, θ = about 20 to 25 °).

More specifically, when the tailgate 5 pulled up by the operator as described above rises slightly before the highest rising position, the upper edge portion thereof rises to the upper and lower branches 78a of the bracket 78, as shown in FIG. It enters between 78b and presses the stretched portion of the wire 75. As a result, the stretched portion is bent as shown in FIG. 10, and the wire 75 is pulled toward the stretched portion as shown by the arrow a in this figure, and the camera 7 is pulled downward.

In the present embodiment, the bending of the stretched portion in this way causes the amount of wire 75 to be pulled up to rotate the camera 7 around the support pin 72 in the support member 71, from the normal position to the monitoring position. It is set to the amount of movement for switching. Therefore, when the tailgate 5 is pulled up and the dust inlet 4 is fully opened as described above, the camera 7 is switched to the monitoring position in conjunction with this.

As described above, by swingably supporting the camera 7 on the support member 71, a direction switching mechanism capable of switching the optical axis A of the image pickup lens 70 in the first and second directions is configured. Then, a mechanical interlocking switching means for switching the direction of the camera 7 according to the opening and closing of the tailgate 5 by the tension coil spring 73 that pulls the camera 7 upward and the wire 75 that pulls the camera 7 downward against its elastic force. Is configured.

When the camera 7 is switched to the monitoring position and the optical axis A is directed downward, the center of the image pickup lens 70 is in front of the dust inlet 4 in a plan view (not shown, but in a plan view from above). It will be located between the edge portion 4a and the trailing edge portion 4b (including directly above the front edge portion 4a and the trailing edge portion 4b). In the example of FIG. 5, the center of the image pickup lens 70 is located almost directly above the front edge portion 4a of the dust input port 4.

At this time, as shown in FIG. 5, the optical axis A of the image pickup lens 70 substantially passes through the trailing edge portion 4b of the dust input port 4 in a lateral view, and is almost vertically downward. Therefore, the distance D between the boundary line B of the dangerous area and the head of the person H behind (the vertical distance D in FIG. 7) in the captured image is considerably close to the actual distance D shown in FIG. Become. Therefore, it is possible to more accurately determine whether or not the person H has crossed the boundary line B and entered the dangerous area (determination in step S6 of the flow of FIG. 6).

Moreover, since the optical axis A of the image pickup lens 70 is directed toward the trailing edge 4b of the dust input port 4 as described above, the trailing edge 4b, that is, the boundary line B of the dangerous area appears in FIG. It will be displayed in the center of the image as if it were. This means that the interval D near the boundary line B in the image is not easily affected by the distortion of the optical system such as the image pickup lens 70, which is advantageous in accurately performing the above determination.

As described above, according to the person recognition device according to the present embodiment, the direction of the camera 7 arranged above the dust input port 4 in the dust collecting vehicle 100 can be switched, and the optical axis A of the image pickup lens 70 The field of view of the captured image can be sufficiently widened by directing the lens in the first direction diagonally rearward as in the case of a normal back camera. On the other hand, if the optical axis A is switched to the second downward direction, whether or not this person H has invaded a dangerous area based on the distance D between the dust inlet 4 and the person H behind in the captured image. Or, it will be possible to judge more accurately.

That is, by sharing the camera 7 for image processing with the back camera and appropriately switching the orientation thereof, it becomes possible to more accurately determine whether or not the person H is in a dangerous area. Then, the safety is ensured by stopping the operation of the dust loading device based on the determination result.

Further, in the above-described embodiment, when the operator pulls up the tailgate 5 and the dust inlet 4 is fully opened, the camera 7 is interlocked to switch to the downward monitoring position, and the tailgate 5 is operated as such. It is possible to accurately determine whether or not the lifted worker is in a dangerous area. Moreover, since the mechanical structure is such that the rise of the tailgate 5 (displacement to the opening side) is transmitted to the camera 7 by the wire 75, the cost rise can be suppressed.

-Other embodiments-
Although the preferred embodiment of the present invention has been described above, this merely shows one specific example and does not particularly limit the present invention. Therefore, the specific configuration and the like can be appropriately redesigned. is there. For example, in the above embodiment, the image processing unit 8 is interposed in the energization line K3 to the control device PLC, and the energization to the control device PLC is cut off by opening the relay switch SW4. Not limited.

That is, for example, when it is determined in the image processing unit 8 that the person H is in a dangerous area, a stop signal is output to the control device PLC, and the control device PLC receives the stop signal. The output of the control signal to the SOLd may be stopped, and any other configuration capable of stopping the operation of the dust loading device can be adopted.

Further, in the above-described embodiment, when the image processing unit 8 receives a stop signal from the image processing unit DSP, the central processing unit CPU opens the relay switch SW4, but the present invention is not limited to this. For example, the signal from the limit switches LS4 and LS5 for detecting the operating state of the rotating plate 10 of the dust loading device is configured to be input not only to the control device PLC but also to the image processing unit 8, and the rotating plate 10 is configured. May be set to open the relay switch SW4 when is in the dangerous angle range Z (see FIG. 2) and the head of the person H is in the dangerous area.

That is, even while the dust loading device is operating, when the rotating plate 10 is rotating outside the dangerous angle range Z, there is no possibility that a part of the operator's body will be caught by this, so this Occasionally, even if the person H is in a dangerous area, the operation of the dust loading device is not stopped. By doing so, the frequency of unnecessary operation stoppage of the dust loading device can be reduced, and convenience can be improved.

Further, as shown in FIG. 5, in the above-described embodiment, when the optical axis A faces the second downward direction, the center of the image pickup lens 70 is substantially the front edge portion 4a of the dust input port 4. It is located directly above and the optical axis A is directed toward the trailing edge 4b, but from the viewpoint of determination accuracy, the center of the image pickup lens 70 is positioned directly above the trailing edge 4b of the dust inlet 4. , It is preferable to direct the optical axis A vertically downward from there.

Further, in the above embodiment, the wire 75 is pulled by the ascending tailgate 5 to swing the camera 7 downward, but the present invention is not limited to this, and for example, the ascending tailgate 5 is sensored. The direction of the camera 7 may be switched by an actuator such as an electric motor, a cylinder, or a solenoid according to the detection. Further, the actuator may be operated in response to the operation of the dust loading device to switch the direction of the camera 7.

That is, as shown in FIG. 11, as an example, a geared motor 79 (electric motor with a speed reducer) is attached to the support member 71 of the camera 7, and the rotation shaft thereof is directly connected to the end of the support pin 72 of the camera 7. In this case, the tension coil spring 73, the connecting pin 74, the wire 75, the pulleys 76, 77, the bracket 78, and the like as in the above embodiment are unnecessary, and the slit 71e is not provided in the base 71a of the support member 71. ..

Then, when the operation of the dust loading device is started by the on operation of the start switch or the like, the geared motor 79 is operated by the control device PLC, and the camera 7 is configured to switch from the normal position to the monitoring position. Good. Further, when the operation of the dust loading device is completed, the geared motor 79 may be operated accordingly to switch the camera 7 from the monitoring position to the normal position.

It should be noted that the fact that the camera 7 is in the normal position or the monitoring position in such a configuration can be determined by the control device PLC by inputting the signal from the encoder built in the geared motor 79. Alternatively, although not shown, a proximity switch or the like is provided between the camera 7 and its support member 71, and the output signal thereof is input so that the control device PLC determines that the camera 7 is in the normal position or the monitoring position. You may.

Furthermore, instead of switching the orientation of the camera 7 itself, the imaging lens 70 may be configured to be movable so that the orientation of the optical axis A may be switched, or the camera 7 and the imaging lens 70 may be switched. Both of them may be fixed so as not to move, and only the direction of the optical axis A may be switched by using, for example, a reflecting mirror.

Further, in the above embodiment, the case where the present invention is applied to the garbage truck 100 equipped with the so-called rotary dust loading device is described, and the main parts of the dust loading device are the rotating plate 10 and the pushing plate 20. However, the structure is not particularly limited, and the main part of the dust loading device may be composed of an elevating plate and a pushing plate, and the structure thereof is not particularly limited.

Further, in the above-described embodiment, the garbage truck 100 is exemplified as the work vehicle, but the present invention is not limited to this, and can be applied to various work vehicles. For example, it is also preferable to apply the present invention to a work vehicle in which a work device for heat-treating an article is provided in the packing box and it is dangerous for a person to get too close to the article inlet.

100 Garbage truck (worker volume)
1 Chassis 2 Dust storage box (packing box)
3 Garbage input box (packing box)
4 Dust inlet 4a Front edge 4b Rear edge 5 Tailgate (door of dust inlet)
7 Camera 70 Imaging lens 71 Support member (direction switching mechanism 73 tension coil spring (urging member: interlocking switching means))
75 wire (transmission member: interlocking switching means)
79 Geared motor (actuator: interlocking switching means)
8 Image processing unit (image processing device)
10 Rotating plate (dust loading device, working device)
13 Hydraulic motor (dust loading device, working device)
20 Push-in plate (dust loading device, working device)
24 Push-in cylinder (dust loading device, working device)
A Central processing unit (emergency stop device) of the optical axis CPU image processing unit of the imaging lens
SW4 Image processing unit relay switch (emergency stop device)

Claims (7)

It is a person recognition device that is installed in a garbage truck equipped with a dust input box on the chassis and recognizes a person in the vicinity of the dust input port that opens in the dust input box.
The dust loading box is equipped with a dust loading device.
Said above the dust inlet camera is arranged, and the input image data photographed by the camera, the dust inlet determines the image processing apparatus whether a person is in a predetermined area in the vicinity in the image I have
It is provided with a direction switching mechanism that can switch the optical axis of the image pickup lens of the camera between a first direction that is directed from vertically downward to a distance from the vehicle and a second direction that is closer to vertically downward than this first direction. ,
It is equipped with an interlocking switching means that operates the direction switching mechanism according to the opening and closing of the door of the dust inlet.
The interlocking switching means switches the direction of the optical axis of the imaging lens to the second direction when the door is opened and the operation of the dust loading device is started, while the door is closed and the dust loading device is operated. A person recognition device for a dust collecting vehicle , characterized in that the direction of the optical axis of the image pickup lens is switched to the first direction when the operation is completed. The person recognition device for a garbage truck according to claim 1 , wherein the direction switching mechanism is configured to change the direction of the camera itself. The interlocking switching means includes an urging member that urges the camera so that the optical axis of the imaging lens faces the first direction.
With a transmission member that transmits the displacement of the dust inlet to the opening side to the camera and changes the direction of the camera so that the optical axis faces the second direction against the urging force of the urging member. The person recognition device for a garbage truck according to claim 1 or 2 , comprising the above. The interlocking switching means operates the actuator in response to the operation of the start switch of the dust loading device to switch the direction of the optical axis of the image pickup lens from the first direction to the second direction. The person recognition device for a dust collecting vehicle according to claim 1 or 2 , which is configured to operate the mechanism. When the optical axis of the image pickup lens of the camera is directed in the second direction, the center of the image pickup lens is located between one edge and the other edge of the dust inlet in a plan view. The person recognition device for a dust collecting vehicle according to any one of claims 1 to 4. The optical axis of the imaging lens of the camera, when directed in a second direction, passes through the edge of the dust inlet at the side view, according to any one of claims 1-5 dust Person recognition device for collection vehicles. If it is determined that the person is in a predetermined area in the pre-Symbol image processing apparatus includes an emergency stop device for stopping the operation of the dust loading device, according to any one of claims 1 to 6 A dust collector equipped with a person recognition device.

Images