JP2018154464A - Garbage collector and person recognition device mounted in the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To arrange a camera 7 above a garbage slot 4 of a garbage collector 100, and enable a person H near the garbage slot 4 to be more accurately recognized by inputting data on a taken image into an image processing unit 8 (image processor).SOLUTION: In an image processing unit 8, data on characteristics of an object image of an image are compared with data on characteristics of a person's head, and it is determined whether or not the object image represents the person's head (step S3 to step S5: a person identification part). It is determined weather or not the object image representing the person's head enters a predetermined area near a garbage slot (step 6: a person position determination part). The data on the characteristics of the person's head include the size, position and shape of an attachment such as a hat or a helmet.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a person recognition apparatus that recognizes an operator or the like in the vicinity of a dust inlet of a garbage collection vehicle by image processing technology, and particularly relates to recognition of a person in an image taken from above by a camera.

  Conventionally, garbage collection vehicles have been equipped with a dust loading device in the dust throwing box provided at the rear of the chassis, and the dust thrown into the dust throwing box is put on a rotating plate or loading. It is scraped with a plate and loaded into the trash storage box. In addition, in order to prevent workers who put dust into the dust input port from being inadvertently caught in the dust loading device, there are various monitoring systems that monitor people in the vicinity of the dust input port. Proposed.

  For example, in the monitoring system described in Patent Document 1, a camera as an imaging unit is provided at the upper rear portion of the dust box, and the lower dust inlet and its rear are photographed. If the image data captured by the camera is transmitted to the image processing device during the operation of the dust loading device and it is determined that a person has entered the entry prohibition area set in advance in the image, The operation of the loading device is stopped.

Japanese Patent No. 4283568

  By the way, in the monitoring system of the conventional example, a camera is disposed above the dust inlet, and the optical axis of the imaging lens is turned from the vertically downward to the rear, so that it appears in FIGS. As shown, not only the head of the person behind but also its face will appear in the image. In this way, if a person's face appears in the image and the shape and positional relationship of characteristic eyes, nose and mouth are clear, the person can be recognized relatively easily.

  However, as the optical axis is turned backward as described above, for example, strong sunlight in the morning and evening is incident on the imaging lens, and the contrast of the image may decrease. Moreover, since rain and snow are likely to adhere to the imaging lens, there is a concern that the field of view may be blocked by these attached substances. Therefore, in order to avoid these problems, it is desirable to make the optical axis of the imaging lens as downward as possible.

  However, when the imaging lens is turned downward, the field of view of the camera is narrowed rearward, and the vicinity of the dust inlet is almost looked down from directly above. It becomes difficult to appear in the image. That is, in an image looking down at a person from above, the shape and positional relationship of eyes, nose, and mouth are not clear, making it difficult to recognize that the person is a person.

  Therefore, in that case, for example, depending on the size of the head and the condition of the hair, it must be recognized that the person is a person, but an operator who loads dust is wearing a hat on a rainy day, for example. Or wear rain hood with hood. In addition, the worker may be wearing a helmet, and in such a case, there is a risk of making an error in recognizing the person.

  The present invention has been made paying attention to the circumstances peculiar to such a garbage collection vehicle, so that a person can be more accurately recognized based on an image photographed by a camera disposed above the dust inlet. The purpose is to.

  The person recognition apparatus of the present invention has a camera disposed above the dust inlet of the garbage truck, and inputs data of an image taken by the camera to the image processing apparatus to recognize a person in the vicinity of the dust inlet. The target is to do.

  The image processing apparatus compares the feature data of the object image in the image with the feature data of the person's head, and determines whether the object image represents the person's head, A person position determination unit for determining whether or not the object image determined to represent the person's head by the person identification unit is in a predetermined area near the dust inlet, The feature data includes a size, a position, and a shape of an attachment to the head.

  In the person recognition apparatus having the above-described configuration, a person disposed in the vicinity of the lower dust inlet is photographed by the camera disposed above the dust inlet, and the image is input by the person identification unit of the image processing apparatus that has input the image data. The feature data of the inside object image is compared with the feature data of the person's head. The head feature data is obtained by extracting features such as the state of the hair in addition to the size and shape of the entire head in an image obtained by photographing a variety of human heads from above.

  In the present invention, the feature data of the head further includes the size, position, and shape of an object attached to the head, such as a hat, a helmet, and a rain hood. Even if the worker who loads the garbage wears a hat or a rain hood, or wears a helmet, the object image is a person based on the characteristics of the attached items. Can be judged.

  That is, when the camera is arranged so as to look down at the person, it can be recognized that the person is not only based on the state of the hair, but also based on the characteristic of the attachment to the head assumed in advance. Therefore, if it is determined that the object image determined to represent a person is in a predetermined area near the dust inlet, safety can be ensured by stopping the operation of the dust loading device. .

  Preferably, the feature data of the head not only includes the attachment to the head as described above, but also the size, position, and position of what the operator is supposed to attach to the face (attachment to the face) The shape is also included, and specifically includes glasses and a mask. In other words, as described above, when the imaging lens of the camera is turned downward, the face of a person is difficult to appear in the image, and it is difficult to determine that the person is a person based on information on eyes, nose, and mouth.

  However, since glasses, a mask, and the like are mounted so as to protrude forward from the face, they clearly appear in an image taken from above. Moreover, for example, in the case of eyeglasses, even if the individual design is different, in an image taken from above, it is a strip that extends in a generally flat left and right direction. This is because it is easy to determine.

  More preferably, the object image that satisfies the condition of the head feature data is determined to represent the head (temporary determination), and the moving speed of the object image is calculated. It is determined (mainly determined) that it represents the head only when is equal to or less than a preset threshold value. In this way, it is possible to distinguish the garbage bag from the person's head based on the difference in moving speed from the garbage bag thrown into the garbage slot by the operator.

  In other words, the present invention is a garbage truck equipped with the person recognition device according to any one of claims 1 to 5. That is, the dust input port is opened at the back of a dust input box provided at the rear of the dust collecting vehicle, and a dust loading device capable of loading dust into the dust container is provided in the dust input box. ing. As described above, when the image processing device determines that there is a person in a predetermined area near the dust inlet, the operation of the dust loading device is stopped by the emergency stop device.

  According to the person recognition apparatus for a garbage collection vehicle according to the present invention, the vicinity of the dust inlet is photographed so as to look down from above, and the person's head is determined by an image processing technique. That is, by comparing the feature data of the object image in the image with the feature data including not only the size of the head and the state of the hair, but also wearing items such as a hat and rain hood, it is the head of the person Can be accurately determined. And safety | security is ensured by stopping a refuse loading device as needed based on this determination.

It is a side view which shows the refuse collection vehicle which concerns on embodiment of this invention. It is explanatory drawing of the action | operation of the refuse loading apparatus with which the refuse collection vehicle of FIG. 1 was equipped. FIG. 2 is a hydraulic circuit diagram of a dust loading device of the garbage collection vehicle of FIG. 1. It is the schematic which shows the control apparatus of the garbage truck of FIG. 1, and its input-output state. It is explanatory drawing which shows schematic structure of the person recognition apparatus with which the garbage truck of FIG. 1 was equipped. It is a flowchart which shows an example of an image processing routine. It is explanatory drawing which shows an example of the image image | photographed with the camera. It is a flowchart shown about temporary determination of a person's head. It is a figure explaining the characteristic data of the head seen from the upper part, Comprising: (a) when wearing spectacles, (b) when further wearing a hood, (c) is a helmet and a mask In the case, (d) shows the case of a hood and a mask, respectively.

  Hereinafter, an embodiment 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 the sake of convenience, the front, rear, left and right of the garbage truck may be simply referred to as front, rear, left and right.

  FIG. 1 shows a garbage collection vehicle 100 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 are provided on the chassis 1. The rear opening of 2 and the opening on the front surface of the dust box 3 are communicated with each other. In addition, the dust box 3 is pivotally supported by a left and right pivot 3a provided on the upper portion thereof, and is tilted by a pair of left and right tilt cylinders (not shown).

  In addition, a rectangular dust inlet 4 (see also FIG. 7) for throwing dust is opened at a lower portion of the rear side of the dust throwing box 3 and is opened and closed by a tailgate 5 that can be raised and lowered. It is like that. A switch box 6 for operations such as the operation of the dust loading device is provided on the left side of the dust inlet 4, and above the dust inlet 4, as will be described in detail later, A camera 7 is disposed so as to photograph the vicinity of the insertion port 4.

  As shown in an enlarged view in FIG. 2, a dust loading device for loading the thrown dust into the dust container 2 is installed inside the dust throwing box 3. The dust loading device of the present embodiment is a so-called rotary type that scrapes up dust by the rotation of the rotating plate 10 and pushes it into the dust container 2 by the pushing plate 20. That is, first, the rotating shaft 11 is constructed so as to extend in the width direction in the lower part in the dust box 3, and the base end side of the rotating plate 10 is fixed thereto.

  In the illustrated example, a hydraulic motor 13 that can rotate forward and backward is connected to an end of the rotating shaft 11 via a speed reduction mechanism 12. Therefore, the rotation of the hydraulic motor 13 is increased in torque 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 moves to the front-back direction along the bottom wall of the dust box 3 formed in this.

  On the other hand, the pushing plate 20 is provided over the entire width direction of the dust throwing box 3 above the rotating plate 10 and can swing in the front-rear direction around the swing shaft 21 in the left-right direction provided in the upper part thereof. It is supported by. Further, the pushing plate 20 is provided with an extending portion 22 extending upward from the swing shaft 21, and a pushing cylinder 24 is installed between the extending portion 22 and a support pin 23 in front of the extending portion 22. The pushing plate 20 is swung back and forth by the expansion and contraction operation.

  That is, as shown by the solid line in FIG. 2, when the pushing plate 20 is at the most swung position (forward limit position) on the dust container box 2 side, the rotating plate 10 moves upward without interfering with the pushing plate 20. The pushing plate 20 swings toward the dust inlet 4 side with a delay. Then, the rotation of the rotating plate 10 continues even after the pushing plate 20 swings most toward the dust inlet 4 and reaches the retreat limit position indicated by the phantom line in FIG.

  The rotating plate 10 thus rotated scrapes dust to the dust container box 2 side and temporarily stops at a set stop position extending to the front dust container box 2 side as shown by a solid line in FIG. Then, the pushing plate 20 is swung to the dust container box 2 side, and the dust on the rotating plate 10 is pushed into the dust container box 2. When the pushing plate 20 reaches the advance limit position again, the rotating plate 10 is rotated upward again.

  As described above, the rotation of the rotating plate 10 and the swinging of the push-in plate 20 are repeated in synchronization with each other, whereby the dust thrown into the dust throwing box 3 is continuously loaded into the dust container box 2 (hereinafter referred to as dust stacking). Is called the “cold operation”). The configuration of the hydraulic circuit and the electronic control unit (control system) for operating the rotating plate 10 and the pushing plate 20 will be described below. For this purpose, the rotating plate 10 and the pushing-in portion are disposed inside the dust 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 that are turned on when the pushing plate 20 is at the forward limit position or the backward limit position, and the switch LS1 and LS2 that are turned on when the rotary plate 10 is at the set stop position. A switch LS3, a switch LS4 that is turned on when the rotary plate 10 is rotated in a positive direction (clockwise in FIG. 1) from the set stop position by a predetermined angle, and a switch LS5 that is turned on when the rotary plate 10 is further rotated by a predetermined angle. Is provided.

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

  As shown in FIG. 2 with hatching, the switches LS4 and LS5 move downward from the front edge portion 4a of the dust inlet 4 while rotating the rotating plate 10 to the rear thereof. The angle range Z until it is closest to the trailing edge 4b is detected. In this angle range Z, there is a risk that the rotating plate 10 may engulf part of the operator's body.

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

-Control system of garbage loading device-
Next, a control system for operating the dust loading device as described above will be described with reference to FIGS. 3 and 4. The control system includes a hydraulic circuit that controls the hydraulic pressure supplied to the hydraulic motor 13 and the pushing 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. 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. Electromagnetic control valve V2. Although not shown, the driving force of the engine is transmitted to the hydraulic pump P via a PTO (power take-off).

  As an example, each of the electromagnetic control valves V1, V2 is composed of a 6-port 3-position electromagnetic direction switching valve. 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 energized, it switches to the second communication position (lower position in the figure) and supplies hydraulic oil to the head side oil chamber.

  When hydraulic oil is supplied from the electromagnetic control valve V1 to the head side oil chamber, the pair of push cylinders 24 are extended to swing the push plate 20 forward. On the other hand, when the hydraulic oil is supplied to the rod side oil chamber, the pair of push cylinders 24 are contracted to swing the push plate 20 backward. Further, when neither solenoids SOLa and SOLb are 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 forward rotation oil chamber of the hydraulic motor 13, and the hydraulic motor 13 Is rotated forward. On the other hand, when the solenoid SOLd is excited, the electromagnetic control valve V2 is switched to the second communication position (upper position in the figure), supplying hydraulic oil to the reverse oil chamber of the hydraulic motor 13, and reversely rotating the hydraulic motor 13. Operate.

  Further, when none 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 of 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 the upper limit of the discharge pressure of the hydraulic pump P.

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

  Further, the upstream end of the energization line K3 is connected so as to branch from the energization line K2 between the key switch SWK and the battery BT, and the signal power supply unit ( (Not shown) is supplied with electric power. That is, the contact cr1 of the relay coil CR1 is interposed on the upstream side of the energization line K3 (the side close to the battery BT). When the relay coil CR1 is turned on, the contact cr1 is closed and the energization line K3 is energized. To come.

  This energization 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. Then, switches SW1 to SW3 that are opened and closed are interposed. When energization is interrupted by these switches SW1 to SW3, the operation of the control device PLC is stopped, whereby the operation of the dust loading device is stopped. As will be described in detail later, an image processing unit 8 is also interposed in the energization line K3.

  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 (the side far from the battery BT) from the contact cr1. Each of these branch lines is provided with the switches LS1 to LS5 described above with reference to FIG. Based on the signals from these switches LS1 to LS5, the positions of the rotary plate 10 and the push plate 20 of the dust loading device, that is, the operating conditions are detected.

  In addition to the switches LS1 to LS5, on the input side to the control device PLC, although not shown, a start and stop switch for the dust loader, a single-action or continuous selection switch for dust load operation, a dust load A selection switch for the insertion operation and the dust discharge 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 the various switches are connected to the input side as described above, the solenoids SOLa to SOLd of the electromagnetic control valves V1 and V2 are connected to the output side (right side in FIG. 4) of the control device PLC. Then, based on the signals input from the switches SW1 to SW3, LS1 to LS5, etc., the control device PLC controls the corresponding solenoids SOLa to SOLd to operate the hydraulic motor 13 and the pushing cylinder 24 according to a preset procedure. It is programmed to output.

  That is, for example, when the dust loading device performs the dust loading operation, both the key switch SWK and the PTO switch SWP on the energization 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 appropriately outputs control signals to the solenoids SOLa to SOLd. .

  In response to 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 pressure is supplied to the hydraulic motor 13 and the push cylinder 24. Thereby, the hydraulic motor 13 and the pushing cylinder 24 are operated, and the rotation of the rotating plate 10 and the swinging of the pushing plate 20 are repeated in synchronization with each other as described above with reference to FIG.

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

  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 pushing cylinder 24 starts contracting operation. As a result, the pushing plate 20 swings to the rear dust inlet 4 side. When the pushing 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 outputting the control signal to the solenoid SOLa, so that the electromagnetic control valve V1 returns to the neutral position, and the swinging of the pushing plate 20 stops. Further, while the pushing plate 20 is oscillating, the rotation of the rotating plate 10 is continued and the dust is scraped into the dust container 2 side. The set stop position is reached and an ON signal is output from the switch LS3.

  In response to this, the control device PLC stops outputting the control signal to the solenoid SOLc of the electromagnetic control valve V2, whereby the electromagnetic control valve V2 returns to the neutral position, and the rotation of the hydraulic motor 13 stops. 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 pushing cylinder 24 starts the extending operation, whereby the pushing plate 20 Begins to swing forward.

  When the pushing plate 20 that swings to the front dust container box 2 pushes the dust on the rotating plate 10 into the dust container box 2 and reaches the forward limit position, an ON signal is output from the switch LS1. In response to this, the control device PLC stops outputting the control signal to the solenoid SOLb, whereby the electromagnetic control valve V1 returns to the neutral position, and the pushing cylinder 24 is extended, that is, the pushing plate 20 is swung 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, there is a possibility that an operator who puts the dust into the dust loading port 4 may be inadvertently caught in the rotary plate 10 or the like. Therefore, in the garbage truck 100 of this embodiment, the camera 7 is disposed so as to photograph the vicinity of the dust inlet 4, and it is determined by image processing that there is a person in a dangerous area near the dust inlet 4. In this case, the operation of the dust loading device is immediately stopped.

  That is, as shown in FIGS. 1 and 2, as shown in FIG. 5, a camera 7 is provided at the upper part of the back of the dust box 3, that is, above the dust slot 4, and its imaging lens. 70 is directed to the vicinity of the lower dust inlet 4. Data of an image photographed by the camera 7 is transmitted to an image processing unit 8 (an image processing apparatus, for example, disposed around the driver's seat as indicated by a broken line in FIG. 1). It is determined whether or not the person H is in a dangerous area (shown with hatching in FIG. 5) between the front edge 4a and the rear edge 4b.

  As described above, during the loading operation of the dust loading device, both the key switch SWK and the PTO switch SWP are closed, and the control device PLC is energized by the energization line K3. As shown in FIG. 4, the image processing unit 8 is interposed in the middle of the energization line K3. If it is determined that the person H is present in a dangerous area, the energization to the control device PLC is cut off. It is supposed to be.

  In the following, a person recognition method by image processing will be described. As schematically shown in FIG. 5, the image processing unit 8 includes a central processing unit CPU and a camera 7 that execute various programs and perform various controls. The image processing unit DSP that performs the following known image processing, the memory M that stores data used in the central processing unit CPU and the image processing unit DSP, and the commands of the central processing unit CPU For example, a relay switch SW4 that opens and closes is provided.

  The camera 7 uses a back camera for the driver to monitor the rear. Although not shown, a monitor for displaying an image taken by the camera 7 is provided around the driver's seat. ing. The image processing unit 8 is provided with an image output unit VOP that displays the result of image processing on the monitor together with the image. 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.

-Image processing routines-
The image processing unit DSP is a general integrated circuit that performs known image processing logic at a high speed. For example, binarization processing of input image data and pixels adjacent to each other in the binarized image data A labeling process for regionizing, a person identifying process for identifying that the region of the object image segmented by labeling is a person image, and determining whether the position of the object image identified as the person image is a dangerous area Person position determination processing to be performed.

  Specifically, the image processing routine will be described with reference to the flowchart of FIG. 6. First, binarization processing is performed in step S1 after the start. This is, for example, processing for setting the maximum luminance value when the luminance value for each pixel in the input image data is greater than or equal to a preset threshold value, and setting the minimum luminance value 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 light quantity change.

  Next, in step S2, a labeling process is performed. This is to process each pixel adjacent to each other in the binarized image data. For example, a plurality of pixels belonging to the same luminance value and closely within a predetermined distance are regarded as one region. . The labeling process is performed on the entire image plane, and a single region is recognized as an object image.

  In subsequent steps S3 to S5, person identification processing is performed for each of the object images. In the present embodiment, as described above with reference to FIG. 5, the camera 7 is disposed above the dust inlet 4 so that the vicinity of the lower dust inlet 4 is photographed from almost directly above. For this reason, the head of the person H is displayed large as shown in the example in FIG. 7, and a part of the face viewed from above is also displayed in the image.

  As will be described in detail later, in the image photographed from above, the shape and positional relationship of eyes, nose and mouth are not clear, and it is difficult to determine that the face is a person based on this. Therefore, in step S3, characteristic data of the head (including the face) set in advance, that is, for example, the size and shape of the head, the state of the hair, and the size and shape of the attachment to the head and face, etc. The object image that satisfies the condition of the feature data is temporarily determined as the head of the person H.

  Thus, processing for discriminating the object image temporarily determined as the head from other object images is performed in steps S4 and S5. First, in step S4, a change in the position of the object image is detected by a difference process of a plurality of pieces of image data input in time series from the camera 7 (a process of obtaining a luminance value difference for each pixel). Then, the moving speed of the object image is calculated by dividing the change in position, that is, the moving distance of the object image by the time required (time interval for acquiring image data).

  Then, in step S5, it is determined whether or not the calculated moving speed is equal to or less than a preset threshold value. This threshold value is set in advance by experiments or the like so that the moving speed of the head of the worker who puts the dust into the dust inlet 4 can be distinguished from the moving speed of the thrown dust. Therefore, if the calculated moving speed is higher than the threshold value, the movement is too fast and it is identified that the head is not the person H, and a negative determination is made (NO) and the routine is ended (END).

  On the other hand, if an affirmative determination is made in step S5 that the moving speed is equal to or less than the threshold value (YES), the object image is determined to be the head of the person H (main determination), and the process proceeds to step S6. Judge whether you are in a set dangerous area. This can be determined based on whether or not the position coordinates of the pixels forming the outer shape of the region forming the object image are ahead of the boundary line B (the rear edge 4b of the dust inlet 4) of the dangerous area.

  Therefore, if an affirmative determination is made that the object image identified as the head of the person H is in a dangerous area (YES), the process proceeds to step S7 to the central processing unit CPU to stop the operation of the dust loading device. A stop signal is output and the image processing routine is ended (END). On the other hand, if it is 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 issued from the image processing unit DSP, the central processing unit CPU that has received this signal opens the relay switch SW4. That is, by energizing a relay coil (not shown) and opening the contact of the switch, the energization to the control device PLC by the energization line K3 is interrupted. As a result, the operation of the control device PLC is forcibly stopped. Therefore, even if there is any abnormality in the control device PLC, energization of all the solenoids SOLa to SOLd of the electromagnetic control valves V1, V2 is stopped. Become.

  Accordingly, the electromagnetic control valves V1 and V2 at the first communication position or the second communication position all return to the neutral position, and as a result, the operations of the hydraulic motor 13 and the pushing cylinder 24 are 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 that stops the operation of the dust loading device.

  Further, by executing steps S3 to S5 of the flow of FIG. 6, the image processing unit DSP compares the feature data of the object image with the feature data of the person's head, The person position which comprises the person identification part which determines whether it represents or not, and also performs step S6, and determines whether the object image showing a person's head is in the predetermined area near the dust inlet A determination unit is configured.

-Temporary judgment of human head-
Next, the provisional determination of the person's head in step S3 of the flow of FIG. 6 will be described in detail with reference to FIGS. As described above, in this embodiment, the camera 7 disposed above the dust inlet 4 is faced down so that the vicinity of the dust inlet 4 is photographed. For this reason, for example, strong morning and evening sunshine is incident, and there is little concern that the contrast of the image is lowered or that rain or snow adheres to the imaging lens 70.

  However, since the imaging lens 70 is directed downward as described above, the camera 7 looks down from near the dust inlet 4 from directly above, and as shown in FIG. While the head is displayed large, the face is crushed up and down. For this reason, the shape and positional relationship of the eyes, nose, and mouth characteristic of the face are not clear, and it is difficult to recognize the head from this information.

  Therefore, it is determined whether or not the head of a person is based mainly on the size and shape of the object image, and also the condition of the hair.However, an operator who loads dust is wearing a hat on a rainy day, for example. Wearing rain wings with a hood or wearing a helmet, and sometimes wearing a helmet, there was a risk of misrecognition of being a person without taking this into account .

  In this embodiment, paying attention to the situation peculiar to such a garbage collection vehicle, as described above, in step S3 of the flow of FIG. 6, in addition to the size and shape of the head, the state of the hair, a hat, a helmet, etc. Whether the head is a person's head, taking into account possible attachments to the head, and taking into account the attachments to the face, such as glasses and masks, and referring to feature data such as the size and shape of these attachments I'm trying to determine.

  Specifically, first, in step S31 after the start of the flow of FIG. 8, the characteristic data of the head set in advance, for example, the size and shape of the head, the state of the hair (the area of the hair area, It is determined whether or not the object image in the image satisfies the feature data condition by referring to the feature data indicating the shape). The feature data is obtained by previously capturing the heads of many people from above and extracting the features, and is stored in the memory M of the image processing unit 8.

  As schematically shown in FIG. 9A, for example, the contour of the object image matches the shape of an ellipse O representing the size and shape of the head, and the whole is covered with hair. When the color is black, an affirmative determination (YES) is made that it is the head of the person H. On the other hand, when the rain hood F is worn as shown in FIG. 9B, the rear side of the hood F has a convex arc shape similar to the head, but a concave arc shape appears on the front side. Its outline does not match the ellipse O.

  In this case, if the condition is not satisfied in step S31, a negative determination (NO) is made, and the process proceeds to step S32. Here, a pre-set headwear (a hat, a rain hood, a helmet) Etc.) is determined with reference to the feature data. In the case of FIG. 9 (b), an affirmative determination (YES) is made that the object image is a head wearing the hood F, because the rear side has a convex arc shape and the front side has a concave arc shape.

  On the other hand, when the person H is wearing the helmet h as shown in FIG. 9C, for example, the outline does not match the ellipse O, and the helmet h is white as shown in the example in the figure. It is difficult to determine the head. In this case, a negative determination (NO) is made at step S32 that the condition is not satisfied, and the process proceeds to step S33. This time, referring to the feature data of the pre-set face attachment (glasses, mask, etc.), this It is determined whether or not the feature data condition is satisfied.

  In the example of FIG. 9 (c), the person H wears the mask M, which protrudes forward from the front heel of the helmet h. ) 9A and 9B, it may be erroneously determined that the head is not the head (NO) in steps S31 and S32. However, even in this case, the glasses G are worn. In step S33, an affirmative determination (YES) is made.

  In this way, when the person H wears the glasses G, even if the glasses are different in design, if they are photographed from above, they will form a generally flat band extending left and right. It is easy to recognize that it is the head of the person H. Further, when both the glasses G and the mask M are worn as shown in an example in FIG. 9D, since the features of both of them appear, it is easier to recognize the person H.

  An object image that is determined to be affirmative (YES) when the condition is satisfied in any of steps S31 to S33 is temporarily determined as the head of the person H in step S34. In step S35, it is determined whether all object images in the image have been determined. If the determination is negative (NO), the process returns to step S31 and the above-described procedure is repeated. If all the object images have been determined, and if an affirmative determination (YES) is made in step S35, the process ends (end) and the process returns to step S3 in the flow of FIG.

  For all object images in the image, a negative determination (NO) is made if the conditions are not satisfied in any of Steps S31 to S33, and an affirmative determination is made that all the object images have been determined in Step S35 ( If YES), the routine ends without returning to step S3 of the flow of FIG. 6 after the processing is ended (END).

  As described above, according to the person recognition apparatus for a dust collection vehicle according to the present embodiment, first, the camera 7 is disposed above the dust input port 4 at the rear of the dust collection vehicle 100, and the imaging lens 70 is substantially disposed. Since it is facing directly below, there is little concern about strong sunlight in the morning and evening, or rain or snow. In addition, since the distance between the boundary line of the dangerous area and the person behind it in the captured image almost represents the actual distance, it is very accurately determined whether or not the person is in the dangerous area by image processing. it can.

  Then, when shooting a person looking down from above, the head appears large in the image, but the face appears to be crushed, so not only the size and shape of the head and the state of the hair, The head characteristic data is set in consideration of an attachment on the head such as a rain hood, and an attachment protruding from the face such as glasses and a mask. Therefore, when the feature data condition is satisfied, it can be accurately determined that the object image represents the head of a person.

  In addition, in the present embodiment, based on the moving speed of the object image temporarily determined as the head, whether or not this is the person's head is identified, and the dust thrown into the dust inlet 4 by the operator. The garbage bag and the head of the worker (person) can be identified by the difference in moving speed from the bag. If it is determined that the worker's head is in a dangerous area, safety is ensured by stopping the dust loading device.

-Other embodiments-
The preferred embodiment of the present invention has been described above. However, this is merely a specific example, and does not particularly limit the present invention. Therefore, the specific configuration and the like can be appropriately changed in design. is there. For example, in the above-described 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 interrupted by opening the relay switch SW4. It is 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 that receives the stop signal outputs the solenoids SOLa˜ of the electromagnetic control valves V1, V2. The output of the control signal to SOLd may be stopped, and any other configuration that can stop the operation of the dust loading device can be employed.

  In the above-described embodiment, the imaging lens 70 of the camera 7 is disposed almost directly above the rear edge 4b of the dust inlet 4, and the optical axis of the imaging lens 70 is vertically downward. Not. Although not shown, the camera 7 is preferably disposed in the middle between the front edge 4a and the rear edge 4b of the dust inlet 4, but may be disposed in front of the front edge 4a. Moreover, it is preferable that the optical axis of the imaging lens 70 is not inclined so much backward from the vertically downward direction, for example, toward the rear edge portion 4 b of the dust inlet 4.

  Further, in the above-described embodiment, what is provisionally determined to be a person's head by image processing is identified as a garbage bag or the like based on the moving speed, but the present invention is not limited to this. There is no need to identify based on.

  Furthermore, the feature data for tentatively determining the person's head includes not only items worn such as hoods and helmets but also items worn on the face such as glasses and masks. For example, the feature data may include only the attachment on the head without including the attachment on the face.

  Furthermore, in the above-described embodiment, the case where the present invention is applied to a garbage collection vehicle 100 equipped with a so-called rotary dust loading device is described. The main parts of the dust loading device are the rotating plate 10 and the pushing plate. Although it is comprised by 20, it is not limited to this, The main part of the dust loading apparatus may be comprised with the raising / lowering board and the pushing board, and the structure is not specifically limited.

100 Dust collection vehicle 1 Chassis 2 Dust storage box 3 Dust input box 4 Dust input 7 Camera 8 Image processing unit (image processing device)
10 Rotating plate (dust loading device)
13 Hydraulic motor (dust loading device)
20 Push plate (dust loading device)
24 Pushing cylinder (dust loading device)
H Person F, h Hood, helmet (wear on head)
G, M Glasses, Mask (Facewear)
Central processing unit of CPU image processing unit (emergency stop device)
Image processing unit (person identification unit, person position determination unit) of DSP image processing unit
SW4 Image processing unit relay switch (emergency stop device)

Claims (6)

A person recognition device in which a camera is disposed above the dust inlet of the garbage truck and the image data captured by the camera is input to the image processing device to recognize a person in the vicinity of the dust inlet. There,
In the image processing apparatus,
Comparing the feature data of the object image in the image with the feature data of the person's head, and determining whether or not the object image represents the person's head;
A person position determination unit that determines whether or not the object image determined to represent the head of the person by the person identification unit is in a predetermined area near the dust inlet,
The person recognition apparatus for a garbage truck, wherein the human head characteristic data includes the size, position, and shape of an object attached to the head.   The person recognition apparatus for a garbage truck according to claim 1, wherein the attachment to the head includes a hat, a helmet, and a rain hood.   The garbage recognition vehicle person recognition device according to claim 1, wherein the feature data of the head includes a size, a position, and a shape of an attachment on a face.   The person recognition apparatus for a garbage truck according to claim 3, wherein the attachment to the face includes glasses and a mask.   If the feature data of the object image satisfies the condition of the feature data of the head, the person identification unit determines that the head represents the head, calculates the moving speed of the temporarily determined object image, and the moving speed is The person recognition apparatus for a refuse collection vehicle according to any one of claims 1 to 4, wherein if it is equal to or less than a preset threshold value, it is determined to represent a head. The dust input port is opened at the back of a dust input box provided at the rear of the dust collector, and in this dust input box, a dust loading device capable of loading dust into the dust storage box is equipped.
The emergency stop device that stops the operation of the dust loading device when the image processing device determines that a person is in a predetermined area near the dust inlet, 6. A garbage truck equipped with the person recognition device described in one.

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