Obstacle detection system for work vehicles, work vehicle, control method for obstacle detection system for work vehicles

Abstract

To enable accurate detection of obstacles and other objects. [Solution] The obstacle detection system for work vehicles is installed on a work vehicle which includes a self-propelled vehicle body and a work structure provided at the front of the vehicle body that can perform predetermined work, and comprises a camera provided at least a part of the work structure on the vehicle body that is capable of photographing the front of the vehicle body and a control device. The control device comprises an exposure control unit that sets an exposure value when the camera takes pictures based on the brightness information of a second region that remains after excluding a first region in which the work structure is captured from the range that can be photographed by the camera, an image acquisition unit that acquires image data of the image taken by the camera using the exposure value set by the exposure control unit, and a detection processing unit that detects obstacles captured in the second region based on the image data acquired by the image acquisition unit.

Description

Technical Field

[0001] The present disclosure relates to an obstacle detection system for a work vehicle, a work vehicle, and a control method for an obstacle detection system for a work vehicle.

Background Art

[0002] In a work vehicle such as a forklift, an image in front of the traveling direction may be captured by a camera, and based on the captured image, an object to be worked or an obstacle may be detected.

[0003] For example, in Patent Document 1, a fixed value of the exposure of a camera is determined according to the usage environment of the camera, the pallet is photographed by the camera with the determined fixed value of the exposure, and based on the data of the image of the photographed pallet, a configuration for recognizing the pallet is disclosed. In this configuration, the pallet is photographed with a plurality of fixed values of the exposure, and the pallet is recognized based on the data of a plurality of images of the pallet photographed with the plurality of fixed values of the exposure.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, in a work vehicle such as a forklift, a work structure such as a fork may be provided at the front part of the vehicle body. If the work structure is located within the imaging range of the camera, the work structure will be reflected in the image captured by the camera. When the work structure is painted in a dark color such as black, the exposure when taking a picture with the camera may be set according to the part of the dark-colored work structure. Then, in the captured image, the area showing in front of the work structure may become overexposed, and it may be difficult to detect an obstacle or the like well.

[0006] This disclosure was made to solve the above problems and aims to provide an obstacle detection system for work vehicles, a work vehicle, and a control method for the obstacle detection system for work vehicles that can detect obstacles and the like effectively. [Means for solving the problem]

[0007] To solve the above problems, the obstacle detection system for work vehicles according to the present disclosure is an obstacle detection system for work vehicles provided on a work vehicle which includes a self-propelled vehicle body and a work structure provided at the front of the vehicle body and capable of performing predetermined work, wherein the vehicle body is provided at the rear of at least a part of the work structure and is capable of photographing the front of the vehicle body and a camera and a control device, wherein the control device includes an exposure control unit which sets an exposure value when the camera takes pictures based on the brightness information of a second region remaining by excluding a first region in which the work structure is captured from the range that can be photographed by the camera, an image acquisition unit which acquires data of an image taken by the camera using the exposure value set by the exposure control unit, and a detection processing unit which detects an obstacle captured in the second region based on the image data acquired by the image acquisition unit.

[0008] The work vehicle relating to this disclosure comprises a self-propelled vehicle body, a work structure provided at the front of the vehicle body and capable of performing predetermined tasks, and an obstacle detection system for work vehicles as described above.

[0009] The control method for an obstacle detection system for a work vehicle according to this disclosure is a control method for an obstacle detection system for a work vehicle as described above, and includes the steps of: acquiring an image captured by the camera; setting an exposure value for when the camera takes a picture based on the brightness information of a second region remaining after excluding a first region in which the work structure is captured from the range that can be captured by the camera in the acquired image; acquiring image data of an image taken by the camera using the set exposure value; and detecting an obstacle captured in the second region based on the image data. [Effects of the Invention]

[0010] According to the obstacle detection system for work vehicles, work vehicle, and control method for the obstacle detection system for work vehicles described herein, obstacles and the like can be detected effectively. [Brief explanation of the drawing]

[0011] [Figure 1] This is a side view of a work vehicle equipped with an obstacle detection system for work vehicles according to an embodiment of the present disclosure. [Figure 2] This is a view of a work vehicle according to an embodiment of the present disclosure, seen from the front. [Figure 3] This figure shows a work vehicle according to an embodiment of the present disclosure in a state where an obstacle in front is detected. [Figure 4] This figure shows an example of an image taken with a camera according to the embodiment of this disclosure. [Figure 5] This figure shows another example of an image captured by a camera according to the embodiments of this disclosure. [Figure 6] This figure shows the hardware configuration of the control device for a work vehicle according to an embodiment of the present disclosure. [Figure 7] This figure shows the functional configuration of a control device according to an embodiment of the present disclosure. [Figure 8] This figure shows an example of an image taken with a camera according to the embodiment of this disclosure in which a person is visible. [Figure 9]It is a diagram showing another example in which a person is captured in an image taken by a camera according to an embodiment of the present disclosure. [Figure 10] It is a flowchart showing the procedure of a control method for an obstacle detection system for a work vehicle according to an embodiment of the present disclosure. [Figure 11] It is a diagram showing the functional configuration of a control device in a modification of an embodiment of the present disclosure. [Figure 12] It is a diagram showing an example of a first region set in an image taken by a camera in a modification of an embodiment of the present disclosure.

Mode for Carrying Out the Invention

[0012] Hereinafter, with reference to the accompanying drawings, embodiments for implementing an obstacle detection system for a work vehicle, a work vehicle, and a control method for an obstacle detection system for a work vehicle according to the present disclosure will be described. However, the present disclosure is not limited to only this embodiment. (Configuration of Work Vehicle) As shown in FIGS. 1 and 2, the work vehicle 1 is a forklift, and includes a vehicle body 2, a work structure 3, and an obstacle detection system 4 for a work vehicle.

[0013] (Configuration of Vehicle Body) The vehicle body 2 includes a driver's seat 2s, a plurality of wheels 2r, and a drive unit (not shown), and is capable of self-running on a floor surface or the ground. The plurality of wheels 2r are rotationally driven by a drive unit such as an engine or a motor. The vehicle body 2 in this embodiment can be driven remotely or automatically under the control of a vehicle control device (not shown). Note that the vehicle body 2 may be manually operated by an operator.

[0014] In the following description, when an operator is seated in the driver's seat 2s, the front as viewed from the operator is the front, the opposite side is the rear, and the direction connecting the front and the rear is the longitudinal direction Da. Also, the direction orthogonal to the floor surface or the ground is the vertical direction Dv, and the direction intersecting the longitudinal direction Da and the vertical direction Dv is the width direction Dw.

[0015] (Configuration of the working structure) The working structure 3 is provided at the front end (front part) of the vehicle body 2 and can perform predetermined work. In this embodiment, the working structure 3 can lift an object and includes a mast part (tilting member) 31 and a fork part 35.

[0016] The mast part 31 has a pair of masts 32 provided at intervals in the width direction Dw, and connecting parts 33A and 33B that connect the pair of masts 32 to each other. The pair of masts 32 are provided at intervals in the width direction Dw. Each of the pair of masts 32 extends in the vertical direction Dv. The connecting parts 33A and 33B extend in the width direction Dw and connect the upper ends and the lower ends of the pair of masts 32 to each other. The mast part 31 can be tilted in the front-rear direction Da around an axis extending in the width direction Dw by a tilting mechanism (not shown).

[0017] The fork part 35 has a backrest 36 and a pair of forks 37. The backrest 36 is provided behind the pair of forks 37. The backrest 36 can be moved up and down in the vertical direction Dv along the pair of masts 32 via a lifting mechanism (not shown). The pair of forks 37 are provided at intervals in the width direction Dw. Each of the pair of forks 37 is formed in an L shape when viewed from the width direction Dw and can slide in the width direction Dw along the backrest 36. The pair of forks 37, together with the backrest 36, can be moved up and down in the vertical direction Dv along the pair of masts 32 by a lifting mechanism (not shown). Here, the work vehicle 1 is provided with a sensor 38 that detects the height of the fork part 35. The sensor 38 outputs information indicating the detected height of the fork part 35 to the control device 6.

[0018] (Configuration of the obstacle detection system for the work vehicle) FIG. 3 is a diagram showing a state in which a work vehicle according to an embodiment of the present disclosure detects an obstacle ahead. As shown in Figure 1, the obstacle detection system 4 for work vehicles includes a camera 5 and a control device 6. Camera 5 is located at the front of the vehicle body 2. As shown in Figure 3, camera 5 photographs the area in front of the vehicle body 2 based on instruction signals output from the control device 6. The instruction signals from the control device 6 include the exposure value for shooting. Based on the instruction signals from the control device 6, camera 5 photographs the area in front of the vehicle body 2 with the exposure value set by the control device 6. Camera 5 operates continuously, for example, while work vehicle 1 is in operation, and takes pictures. Alternatively, camera 5 may be configured to take pictures only when work vehicle 1 is moving.

[0019] Figure 4 shows an example of an image taken with the camera according to the embodiment of this disclosure. Figure 5 shows another example of an image taken with the camera according to the embodiment of this disclosure. As shown in Figure 1, the camera 5 is located behind the fork portion 35 of the work structure 3. In this embodiment, the camera 5 is mounted on the connecting portion 33B provided at the lower end of the fork portion 35. Therefore, as shown in Figures 4 and 5, for example, depending on the height of the fork section 35, at least a part of the work structure 3 may be captured in the image V taken by the camera 5. In this embodiment, a part of the backrest 36 and a part of the pair of forks 37 are captured in image V. The position of the work structure 3 captured in image V changes according to the raising and lowering of the lift section 34. That is, as shown in Figure 5, when the lift section 34 rises, the position of the work structure 3 captured in image V moves upward, and as shown in Figure 4, when the lift section 34 lowers, the position of the work structure 3 captured in image V moves downward.

[0020] The camera 5 shown in Figure 1 has an adjustable tilt angle around an axis extending in the width direction Dw, controlled by an actuator (not shown). The camera 5's tilt angle is automatically adjusted in response to the tilting of the mast section 31, under the control of the control device 6.

[0021] Furthermore, the cockpit 2s and the control room, which is capable of wireless communication with the work vehicle 1, are equipped with a display unit M, such as a monitor device, that displays images (projections) captured by the camera 5. The display unit M may be a smartphone or tablet terminal carried by the operator.

[0022] (Hardware configuration diagram) Figure 6 shows the hardware configuration of the control device for a work vehicle according to the embodiment of this disclosure. As shown in Figure 6, the control device 6 is a computer equipped with various hardware components such as a CPU 61, ROM 62, RAM 63, storage 64 such as an HDD (Hard Disk Drive), and a communication module 65.

[0023] (Functional block diagram) Figure 7 is a diagram showing the functional configuration of the control device according to the embodiment of this disclosure. The control device 6, as shown in Figure 7, includes an image acquisition unit 70, a fork height acquisition unit 71, a database 72, an exposure control unit 73, a detection processing unit 75, and a tilt correction unit 77, by executing a program that the CPU 61 has pre-stored in its own device.

[0024] The image acquisition unit 70 acquires data of the image V captured by the camera 5. If the exposure control unit 73 sets an exposure value, the image acquisition unit 70 acquires data of the image V captured by the camera 5 using the set exposure value. The fork height acquisition unit 71 acquires information indicating the height of the fork section 35, which is detected by the sensor 38.

[0025] Database 72 stores multiple region information corresponding to the height of the fork portion 35. As mentioned above, at least a part of the work structure 3 may be captured in the image V taken by camera 5. Database 72 stores region information, which is the region in which the work structure 3 is captured in the image V taken by camera 5. In this embodiment, as shown in Figures 4 and 5, the region in which the work structure 3 is captured in image V is set as one or more rectangular first regions A1. In this embodiment, in image V, the first region A1 is set in the region in which the backrest 36 of the fork portion 35 of the work structure 3 is captured. In addition to the region in which the backrest 36 is captured, a rectangular first region A1 may also be set in the region in which a pair of forks 37 are captured.

[0026] Database 72 stores coordinate information representing one or more first regions A1 in image V at each of multiple height levels, for example, every 10 cm, when the work structure 3 is set to multiple height levels. Database 72 stores the multiple height levels of the fork section 35 in association with the coordinate information representing the first region A1 at each of the multiple height levels.

[0027] To store such a first region A1 in the database 72, the work structure 3 is first raised and lowered to multiple heights, and then photographed with the camera 5. Based on the images V obtained from the photography, the person in charge designates the part of the work structure 3 that is visible in the image as the first region A1, and stores its coordinate information in the database 72 as region information related to the first region A1.

[0028] The exposure control unit 73 sets the exposure value when the camera 5 takes a picture to detect an obstacle under the control of the control device 6. Based on the region information for the first region A1 obtained from the database 72, the exposure control unit 73 identifies the first region A1 in which the work structure 3 is captured, from the range that can be captured by the camera 5 (the entire area of ​​image V). As shown in Figures 4 and 5, the exposure control unit 73 identifies the remaining second region A2 by excluding the identified first region A1 from the entire area of ​​image V. Based on the brightness information of the identified second region A2, the exposure control unit 73 sets the exposure value. The exposure control unit 73 outputs an instruction signal to the camera 5 that includes the set exposure value. The camera 5 uses the exposure value included in the instruction signal output from the exposure control unit 73 to photograph the area in front of the work vehicle 1.

[0029] The detection processing unit 75 detects obstacles in the second region A2 by performing image processing based on the image V of the front of the work vehicle 1, which is captured using the exposure value set by the exposure control unit 73 and acquired by the image acquisition unit 70. Examples of obstacles to be detected include people located in front of the work vehicle 1, and objects on the floor or ground in front of it. Here, the algorithm for detecting people, objects, etc. as obstacles may be, for example, template matching or deep learning, and there is no limitation on the algorithm used.

[0030] Figure 8 shows an example of an image taken with a camera according to the embodiment of this disclosure in which a person is visible. Figure 9 shows another example of an image taken with a camera according to the embodiment of this disclosure in which a person is visible. Here, as shown in Figures 8 and 9, in the image V captured by camera 5, depending on the height of the fork portion 35, a part of the fork portion 35 may overlap with the image H of the person in front. For example, as shown in Figure 8, when the fork portion 35 is in a low position, in image V, the fork portion 35 overlaps with the lower body of the person in front, and only a part of the person's image H, such as the head or upper body, is displayed. Also, for example, as shown in Figure 9, when the fork portion 35 is in a higher position than in Figure 8, in image V, the fork portion 35 overlaps with the upper body of the person in front, and only a part of the person's image H, such as the lower body, may be displayed. In response, the detection processing unit 75 switches to an image processing mode that allows it to detect that a person is in front of it if it can recognize an image of a part of a person, such as only the head, only the upper body, or only the lower body, in the image V, depending on the height of the fork section 35.

[0031] When the mast section 31 is tilted in the front-rear direction Da, the tilt correction unit 77 corrects the shooting range of the camera 5 by tilting the camera 5 in the front-rear direction Da using an actuator (not shown) according to the tilt angle. Furthermore, the tilt correction unit 77 may correct the display range of the image V captured by the camera 5 on the display unit M according to the tilt angle of the mast unit 31. In other words, even when the mast unit 31 is tilted in the front-rear direction Da, the tilt correction unit 77 will display the same range on the display unit M as when the image captured by the camera 5 is displayed on the display unit M when the mast unit 31 is not tilted in the front-rear direction Da.

[0032] (Procedure for controlling an obstacle detection system for work vehicles) Figure 10 is a flowchart showing the procedure for a control method of an obstacle detection system for a work vehicle according to an embodiment of the present disclosure. As shown in Figure 10, the control method for this work vehicle obstacle detection system 4 includes the steps of acquiring an image (S11), setting an exposure value (S12), acquiring image data captured using the set exposure value (S13), and detecting an obstacle (S14).

[0033] In step S11, the image V captured by the camera 5 is acquired. The image V acquired in step S11 is used in the following step S12 to set the exposure value. If the mast 31 is tilted in the front-rear direction Da, the tilt correction unit 77 adjusts the tilt angle of the camera 5 using an actuator so that the camera 5 faces forward in the horizontal direction.

[0034] In step S12, which sets the exposure value, the exposure value for when the camera 5 takes a picture is set based on the image V acquired in step S11. Specifically, in step S12, the fork height acquisition unit 71 acquires information from the sensor 38 indicating the height of the fork section 35 at that time. Next, the exposure control unit 73 acquires coordinate information of the first region A1 associated with the acquired height of the fork section 35 from the database 72 as region information for the first region A1. Furthermore, based on the acquired coordinate information of the first region A1, the exposure control unit 73 sets the remaining region excluding the first region A1 in the image V acquired in step S11 as the second region A2. The exposure control unit 73 sets the exposure value based on the brightness information of each pixel in the set second region A2. The exposure control unit 73 outputs the set exposure value to the camera 5. Camera 5, having received the set exposure value from control device 6, uses the received exposure value to capture an image V of the front of the work vehicle 1.

[0035] In step S13, which involves acquiring image data captured using the set exposure value, the image acquisition unit 70 acquires the image V captured by the camera 5 using the exposure value set in step S12.

[0036] In step S14, which detects obstacles, the detection processing unit 75 detects obstacles that are visible in the second region A2 based on the image V data acquired in step S13. At this time, the detection processing unit 75 switches the image processing mode to detect that a person is in front of it if an image of a part of a person, such as only the head, only the upper body, or only the lower body, can be recognized in the image V (see Figures 8 and 9), depending on the height of the fork part 35 at that moment. If the height of the fork part 35 does not overlap with the person in front of it, the detection processing unit 75 switches to an image processing mode that detects the presence of a person if an image H of the entire person is detected. If the detection processing unit 75 detects that there is an obstacle ahead, the control device 6 will perform pre-set obstacle response processing, such as reducing the speed of the work vehicle 1 or stopping the work vehicle 1, if the work vehicle 1 is in motion.

[0037] (Effects and Benefits) In the above configuration of the obstacle detection system 4 for work vehicles, work vehicle 1, and control method for the obstacle detection system 4 for work vehicles, the exposure value when the camera 5 takes a picture is set based on the brightness information of the second region A2, which remains after excluding the first region A1 in which the work structure 3 is captured from the range that the camera 5 can capture. This prevents the exposure value from being set according to the work structure 3 that is captured in the image V. As a result, by taking a picture with the camera 5 using the exposure value set based on the brightness information of the second region A2 excluding the work structure 3, it is possible to suppress the influence of the work structure 3 in the first region A1, even if the work structure 3 is dark in color, while also preventing the image V from being overexposed in the second region A2. Therefore, obstacle detection can be performed well.

[0038] Furthermore, by storing region information related to the first region A1 based on the work structure 3 in the database 72, the setting of the second region A2 can be easily performed, and the processing load on the exposure control unit 73 can be reduced.

[0039] Furthermore, in a work vehicle 1 equipped with a work structure 3 that can be raised and lowered, by storing information on multiple regions corresponding to the height of the work structure 3 in a database 72, the setting of the second region A2 can be easily performed according to the height of the work structure 3.

[0040] Furthermore, the tilt correction unit 77 corrects the shooting range of the camera 5 according to the tilting angle of the tilting member 31, thereby enabling good shooting of the area in front of the work vehicle 1 and good detection of obstacles.

[0041] Furthermore, by tilting the camera 5 in the front-rear direction Da according to the tilting angle of the tilting member 31, the area in front of the work vehicle can be captured clearly and obstacles detected effectively, regardless of the tilting state of the tilting member 31.

[0042] (Modified version of the embodiment) In the above embodiment, the database 72 is configured to include one or more rectangular first regions A1 in which the work structure 3 is visible in the image V, as multiple region information corresponding to the height of the fork portion 35. However, the embodiment is not limited to this. Figure 11 shows the functional configuration of a control device in a modified embodiment of the present disclosure. Figure 12 shows an example of a first region set in an image captured by a camera in a modified embodiment of the present disclosure. As shown in Figure 11, the control device 6B in this modified example includes a region extraction unit 79 in addition to the control device 6 shown in the above embodiment.

[0043] As shown in Figure 12, the region extraction unit 79 extracts the first region A11 in which the work structure 3 is captured from the range (image V) that can be captured by the camera 5, by image processing. In step S11, when the camera 5 takes a picture, the first region A11 may be set by acquiring the contour shape of the work structure 3 captured in image V according to the shape of the work structure 3 by image processing. Alternatively, the camera 5 may be used to take pictures with the lift unit 34 at multiple heights in advance, and the first region A11 may be set by acquiring the contour shape of the work structure 3 captured in image V at each height of the lift unit 34.

[0044] In this case, the exposure control unit 73 removes the first region A11 extracted by the region extraction unit 79 from the image V and sets the second region A12.

[0045] With the modified configuration described above, the first region A11 in which the working structure 3 is reflected can be extracted by image processing, thereby allowing the first region A11 to be defined with greater accuracy, and the second region A12 obtained by removing the first region A11 can be defined with greater accuracy.

[0046] (Other variations of the embodiment) Furthermore, to set the first region A11 to match the shape of the working structure 3, other methods can be employed instead of using image processing as described above. For example, instead of camera 5, a compound-lens camera may be used in advance to take images with the lift unit 34 at multiple height levels, and the control device 6 may be used to estimate the distance to each part within the shooting range. Alternatively, a distance sensor or the like may be used instead of a compound-lens camera. In this case, it is preferable to store data in the database 72 for the distance Da in the longitudinal direction from the camera 5 to the work structure 3 for each type of work vehicle 1. In this case, the region extraction unit 79 determines that any part of the image captured by the compound-eye camera that is within a predetermined distance range registered in the database 72 is a work structure 3. Alternatively, the region extraction unit 79 may determine that anything within a predetermined distance range from the camera 5 is a work structure 3, and set the region in which this predetermined distance range is captured as the first region A11 in which the work structure 3 is captured. In this case, the distance Da in the front-to-back direction from camera 5 to work structure 3 may be estimated using deep learning.

[0047] (Other embodiments) Although embodiments of this disclosure have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments and may include design changes and the like that do not depart from the gist of this disclosure. In the above embodiment, the fork portion 35 of the work structure 3 that is visible in the image V is set as the first regions A1 and A11, but this is not limited to this. For example, if the camera 5 is located behind the mast portion 31 of the work structure 3, the mast portion 31 may be visible in the image V. In this case, in addition to the fork portion 35, the region in which the mast portion 31 is visible may also be set as the first regions A1 and A11.

[0048] Furthermore, although a forklift was used as an example of the work vehicle 1 in the above embodiment, the work vehicle 1 is not limited to this, and may be, for example, an excavator, bulldozer, agricultural machinery, etc.

[0049] Furthermore, a program to implement all or part of the functions of the control device 6 may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be loaded into a computer system and executed to perform processing by each functional unit. Here, "computer system" includes hardware such as the OS and peripheral devices. Also, if a WWW system is used, "computer system" also includes the homepage provisioning environment (or display environment). Furthermore, "computer-readable recording medium" refers to portable media such as CDs, DVDs, USBs, and storage devices such as hard disks built into the computer system. In addition, if this program is distributed to the control device 6 via a communication line, the control device 6 that receives the program may unpack it into storage 64 and execute the above processing. Furthermore, the above program may be for implementing only a part of the functions described above, and may also be able to implement the above functions in combination with a program already recorded in the computer system.

[0050] <Note> The control method for the obstacle detection system 4 for work vehicles, the work vehicle 1, and the obstacle detection system 4 for work vehicles described in the embodiment can be understood, for example, as follows.

[0051] (1) The obstacle detection system 4 for a work vehicle according to the first embodiment is an obstacle detection system 4 for a work vehicle that is installed on a work vehicle 1 which includes a self-propelled vehicle body 2 and a work structure 3 provided at the front of the vehicle body 2 and capable of performing predetermined work, and the vehicle body 2 is provided at the rear of at least a part of the work structure 3 and is equipped with a camera 5 capable of photographing the front of the vehicle body 2 and control devices 6, 6B, wherein the control devices 6, 6B include an exposure control unit 73 which sets an exposure value when the camera 5 takes pictures based on the brightness information of the second regions A2, A12 that remain after excluding the first regions A1, A11 in which the work structure 3 is captured from the range that can be photographed by the camera 5, an image acquisition unit 70 which acquires data of the image taken by the camera 5 using the exposure value set by the exposure control unit 73, and a detection processing unit 75 which detects obstacles captured in the second regions A2, A12 based on the data of the image V acquired by the image acquisition unit 70. Examples of work vehicles 1 include forklifts, excavators, bulldozers, and various agricultural machinery.

[0052] This obstacle detection system 4 for work vehicles sets the exposure value when the camera 5 takes a picture based on the brightness information of the second region A2 and A12, which remain after excluding the first region A1 and A11, in which the work structure 3 is captured, from the range that the camera 5 can capture. This prevents the exposure value from being set to match the work structure 3 that is captured in the image V. As a result, by taking a picture with the camera 5 using the exposure value set based on the brightness information of the second region A2 and A12 excluding the work structure 3, it is possible to suppress the influence of the work structure 3 in the first region A1 and A11 while suppressing overexposure in the second region A2 and A12 of the image V. Therefore, obstacle detection can be performed well.

[0053] (2) The obstacle detection system 4 for work vehicles according to the second embodiment is the obstacle detection system 4 for work vehicles according to (1), wherein the control devices 6, 6B further include a database 72 that stores region information relating to the first regions A1, A11 set based on the work structure 3, and the exposure control unit 73 sets the second regions A2, A12 based on the region information stored in the database 72.

[0054] This allows for easy configuration of the second regions A2 and A12 by storing region information for the first regions A1 and A11 based on the work structure 3 in the database 72, thereby reducing the processing load on the exposure control unit 73.

[0055] (3) The obstacle detection system 4 for a work vehicle according to the third embodiment is the obstacle detection system 4 for a work vehicle according to (2), wherein the work structure 3 is movable up and down in the vertical direction Dv relative to the vehicle body 2, and is further provided with a sensor 38 on the vehicle body 2 for detecting the height of the work structure 3, the database 72 stores a plurality of region information corresponding to the height of the work structure 3, the exposure control unit 73 acquires the region information corresponding to the height of the work structure 3 detected by the sensor 38 from the database 72, and sets the second regions A2 and A12 based on the acquired region information.

[0056] As a result, in a work vehicle 1 equipped with a work structure 3 that can be raised and lowered, by storing information on multiple regions corresponding to the height of the work structure 3 in a database 72, the settings of the second regions A2 and A12 can be easily made according to the height of the work structure 3.

[0057] (4) The obstacle detection system 4 for work vehicles according to the fourth embodiment is any one of the obstacle detection systems 4 for work vehicles described in (1) to (3), wherein the control device 6B further comprises a region extraction unit 79 that extracts a first region A11 in which the work structure 3 is captured from the range that can be photographed by the camera 5 by image processing, and the exposure control unit 73 sets the second region A12 based on the first region A11 extracted by the region extraction unit 79.

[0058] This allows for more accurate setting of the first region A11 by extracting the first region A11 in which the working structure 3 is captured through image processing, and also allows for more accurate setting of the second region A12 obtained by removing the first region A11.

[0059] (5) The obstacle detection system 4 for work vehicles according to the fifth embodiment is the obstacle detection system 4 for work vehicles according to (4), wherein the area extraction unit 79 extracts as the first area A11 an area in which an object located within a predetermined distance range from the camera 5 is captured within the range that can be photographed by the camera 5.

[0060] This allows for a better definition of the area in which the working structure 3 is captured by extracting the region containing objects located within a predetermined distance range from camera 5 as the first region A11.

[0061] (6) The obstacle detection system 4 for work vehicles according to the sixth embodiment is any one of the obstacle detection systems 4 for work vehicles described in (1) to (5), wherein the detection processing unit 75 detects a person that is visible in the second regions A2 and A12.

[0062] As a result, the detection processing unit 75 can detect people appearing in the second regions A2 and A12, thereby suppressing the influence of the work structure 3 and enabling accurate detection of people appearing in the second regions A2 and A12 from the image V of the second regions A2 and A12, which has been optimized by setting appropriate exposure values ​​to prevent overexposure.

[0063] (7) The seventh aspect of the obstacle detection system 4 for work vehicles is the same as the obstacle detection system 4 for work vehicles described in (6), wherein the work structure 3 is movable up and down in the vertical direction Dv relative to the vehicle body 2, and the detection processing unit 75 switches to a mode that can detect a portion of a person that is visible in the second areas A2 and A12, according to the height of the work structure 3.

[0064] As a result, when the work structure 3 rises or falls, depending on its height, a part of a person's body may overlap with the work structure 3 in the image V from the camera 5, and only a part of the person, such as only the upper body, only the head, or only the lower body, may be captured in the second regions A2 and A12 of image V. In such cases, by switching to a mode that can detect the part of the person captured in the second regions A2 and A12 according to the height of the work structure 3, a person located in front of the work vehicle 1 can be detected with higher accuracy.

[0065] (8) The work vehicle 1 according to the eighth embodiment comprises a self-propelled vehicle body 2, a work structure 3 provided at the front of the vehicle body 2 and capable of performing predetermined work, and any one of the work vehicle obstacle detection systems 4 from (1) to (7).

[0066] This makes it possible to provide a work vehicle 1 equipped with an obstacle detection system 4 for work vehicles that allows for easy setting of second areas A2 and A12 according to the height of the work structure 3.

[0067] (9) The work vehicle 1 according to the ninth embodiment is the work vehicle 1 of (8), wherein the work structure 3 and the camera 5 are provided on a tilting member 31 that can tilt in the front-rear direction Da relative to the vehicle body 2, and the control devices 6, 6B are The system further includes a tilt correction unit 77 that corrects the shooting range of the camera 5 according to the tilt angle of the tilting member 31.

[0068] As a result, the tilt correction unit 77 corrects the shooting range of the camera 5 according to the tilt angle of the tilting member 31, thereby enabling good shooting of the area in front of the vehicle and good detection of obstacles.

[0069] (10) The work vehicle 1 according to the tenth embodiment is the work vehicle 1 of (9), wherein the camera 5 is provided so as to be tiltable in the front-rear direction Da with respect to the tilting member 31, and the tilt correction unit 77 tilts the camera 5 in the front-rear direction Da according to the tilting angle of the tilting member 31.

[0070] As a result, by tilting the camera 5 in the front-rear direction Da according to the tilting angle of the tilting member 31, the area in front of the vehicle can be captured clearly and obstacles detected effectively, regardless of the tilting state of the tilting member 31.

[0071] (11) The work vehicle 1 according to the 11th embodiment is the work vehicle 1 according to (9), further comprising a display unit M that displays an image V taken by the camera 5, wherein the tilt correction unit 77 corrects the display range of the image V taken by the camera 5 on the display unit M according to the tilt angle of the tilting member 31.

[0072] This work vehicle 1 can display the view in front of the vehicle on the display unit M regardless of the tilting state of the tilting member 31, by correcting the display range of the image V captured by the camera 5 on the display unit M according to the tilting angle of the tilting member 31.

[0073] (12) A control method for the obstacle detection system 4 for work vehicles according to the 12th embodiment is a control method for the obstacle detection system 4 for work vehicles according to any one of (1) to (7), comprising: step S11 of acquiring an image V taken by the camera 5; step S12 of setting an exposure value for when the camera 5 takes a picture based on the brightness information of the second regions A2 and A12 that remain after excluding the first regions A1 and A11 in which the work structure 3 is captured from the range that can be photographed by the camera 5 in the acquired image V; step S13 of acquiring data of the image V taken by the camera 5 using the set exposure value; and step S14 of detecting an obstacle captured in the second regions A2 and A12 based on the data of the image V.

[0074] This makes it easy to set the second regions A2 and A12 according to the height of the work structure 3. [Explanation of Symbols]

[0075] 1…Work vehicles 2… Vehicle body 2r…wheel 2s…cockpit 3…Work structure 4… Obstacle detection system for work vehicles 5…Camera 6, 6B...Control device 31…Tilting member 31… Mast section 32... Mast 33A, 33B...Connection part 34... Lift section 35... Fork section 36…Backrest 37... Fork 38...Sensor 61…CPU 62...ROM 63...RAM 64... Storage 65...Communication module 70...Image acquisition unit 71... Fork height acquisition unit 72…Database 73…Exposure control unit 75...Detection Processing Unit 77...Tilt correction section 79…Region extraction part A1, A11…first area A2, A12…Second area H…statue M…Display section V...Image

Claims

1. An obstacle detection system for a work vehicle, which includes a self-propelled vehicle body and a work structure provided at the front of the vehicle body and capable of performing predetermined tasks, The vehicle body is provided with a camera located at least a portion of the work structure and capable of photographing the front of the vehicle body, A control device is provided, The control device is An exposure control unit sets the exposure value when taking a picture with the camera based on the brightness information of the second region remaining after excluding the first region in which the work structure is captured from the range that can be photographed by the camera, An image acquisition unit that acquires image data captured by the camera using the exposure value set by the exposure control unit, The system includes a detection processing unit that detects obstacles visible in the second region based on the image data acquired by the image acquisition unit. Obstacle detection system for work vehicles.

2. The control device is The system further comprises a database storing region information relating to the first region set based on the aforementioned work structure, The exposure control unit sets the second region based on the region information stored in the database. Obstacle detection system for work vehicles according to claim 1.

3. The aforementioned work structure is capable of moving up and down relative to the vehicle body. The vehicle body is further equipped with a sensor that detects the height of the work structure, The database stores multiple area information corresponding to the height of the work structure. The exposure control unit obtains region information from the database corresponding to the height of the work structure detected by the sensor, and sets the second region based on the obtained region information. Obstacle detection system for work vehicles according to claim 2.

4. The control device is The camera further comprises a region extraction unit that extracts a first region in which the work structure is captured by image processing from the range that can be photographed by the camera, The exposure control unit sets a second region based on the first region extracted by the region extraction unit. Obstacle detection system for work vehicles according to claim 1 or 2.

5. The region extraction unit, Within the range that can be captured by the camera, the region in which an object located within a predetermined distance range from the camera is captured is extracted as the first region. Obstacle detection system for work vehicles according to claim 4.

6. The detection processing unit detects a person who is visible in the second region. Obstacle detection system for work vehicles according to claim 1 or 2.

7. The aforementioned work structure is capable of moving up and down relative to the vehicle body. The detection processing unit switches to a mode that can detect a portion of a person reflected in the second region, depending on the height of the work structure. Obstacle detection system for work vehicles according to claim 6.

8. A self-propelled vehicle body, A work structure provided at the front of the vehicle body, capable of performing predetermined tasks, The system comprises an obstacle detection system for work vehicles according to claim 1 or 2. Work vehicle.

9. The work structure and the camera are mounted on a tilting member that can be tilted in the front-rear direction relative to the vehicle body. The control device is The system further includes a tilt correction unit that corrects the shooting range of the camera according to the tilt angle of the tilting member. The work vehicle according to claim 8.

10. The camera is provided so as to be able to tilt in the front-rear direction relative to the tilting member, The tilt correction unit tilts the camera in the front-rear direction according to the tilt angle of the tilting member. The work vehicle according to claim 9.

11. The system further includes a display unit that displays images from the aforementioned camera, The tilt correction unit corrects the display range of the image captured by the camera on the display unit according to the tilt angle of the tilting member. The work vehicle according to claim 9.

12. A control method for an obstacle detection system for a work vehicle according to claim 1 or 2, The steps include acquiring an image captured by the aforementioned camera, The steps include setting the exposure value for when the camera takes a picture based on the brightness information of the second region remaining after excluding the first region in which the work structure is captured from the range that can be photographed by the camera in the acquired image, The steps include: acquiring data of an image taken by the camera using the set exposure value; The step includes detecting an obstacle in the second region based on the data of the aforementioned image. A control method for an obstacle detection system for work vehicles.

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