Control device for work vehicle

Abstract

To early calculate an uneven state of a ground surface in front of a traveling direction of a work vehicle.SOLUTION: Disclosed is a control device for a work vehicle capable of traveling on the ground, the control device including a distance acquisition unit configured to acquire, based on sensor information from a sensor attached to the work vehicle, a distance along a predetermined direction from the sensor, the distance being distance information to the ground in front of the work vehicle in a traveling direction, and a parameter calculation unit configured to calculate values of one or more predetermined parameters related to a roughness state of the ground in front of the work vehicle in the traveling direction based on the distance, an angle corresponding to the predetermined direction, and an attachment height of the sensor.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a control device for a work vehicle. [Background technology]

[0002] A technology is known that includes a road surface height detector that sequentially detects the road surface height of the road surface on which the vehicle is to travel at a position a predetermined distance ahead in the direction of travel from the vehicle while it is moving, at predetermined time intervals, and calculates the inclination angle of the road surface on which the vehicle is to travel based on the detected values ​​at multiple points in time. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-116203 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-mentioned conventional technology requires detection values ​​at multiple points in time at specified intervals, making it difficult to detect unevenness of the ground ahead of the work vehicle in the direction of travel (for example, a slope that requires an alarm, etc.) at an early stage.

[0005] Therefore, an object of the present disclosure is to make it possible to quickly calculate the unevenness of the ground ahead in the direction of travel of the work vehicle. [Means for solving the problem]

[0006] In one aspect, there is provided a control device for a work vehicle capable of traveling on a travel surface, comprising: a distance acquisition unit that acquires, based on sensor information from a sensor attached to the work vehicle, distance information to the ground ahead in the traveling direction of the work vehicle, the distance along a predetermined direction from the sensor; A control device is provided that includes a parameter calculation unit that calculates the value of one or more specified parameters related to the unevenness of the ground ahead in the direction of travel of the work vehicle based on the distance, the angle corresponding to the specified direction, and the mounting height of the sensor. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to quickly calculate the unevenness of the ground ahead in the direction of travel of the work vehicle. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram showing an example of a work vehicle to which the control device of the present embodiment can be applied. [Figure 2] FIG. 2 is a diagram illustrating an example of a control system including a control device. [Figure 3] FIG. 2 is a functional block diagram showing functions of a control device. [Figure 4] FIG. 10 is an explanatory diagram of distance information. [Figure 5] FIG. 10 is an explanatory diagram of a method for detecting a step. [Figure 6] FIG. 10 is an explanatory diagram of a method for detecting holes and the like. [Figure 7] FIG. 10 is an explanatory diagram of a method for detecting a slope. [Figure 8] FIG. 10 is an explanatory diagram of a method for detecting a wall or a protrusion. [Figure 9] 4 is a flowchart illustrating an example of a process executed by a control device. DETAILED DESCRIPTION OF THE INVENTION

[0009] Each embodiment will be described in detail below with reference to the accompanying drawings. Note that the dimensional ratios in the drawings are merely examples and are not limiting. Furthermore, shapes and the like in the drawings may be partially exaggerated for the sake of explanation. Furthermore, in the drawings, for ease of viewing, reference symbols may be assigned only to some of the parts that exist with the same attribute.

[0010] 1 is a schematic diagram showing an example of a work vehicle 50 to which the control device 1 of this embodiment can be applied. In FIG. 1 and other figures, the symbol G indicates the ground.

[0011] The work vehicle 50 is an aerial work vehicle and has a work platform 52 that can be raised and lowered. In other words, the height of the work platform 52 is variable. During work, the work platform 52 can be raised to a desired height. Note that the work vehicle to which the control device 1 of this embodiment is applicable is preferably an aerial work vehicle such as the work vehicle 50, but may also be any other type of work vehicle.

[0012] The work vehicle 50 has wheels 54 that enable it to travel on a surface above ground (including underground ground). The wheels 54 may be of a caterpillar type as shown in the figure, or may be normal wheels (for example, four wheels).

[0013] The work vehicle 50 can move forward and backward by rotating the wheels 54. Hereinafter, the direction of travel of the work vehicle 50 will also be simply referred to as the direction of travel.

[0014] A distance measurement sensor 58 is attached to the work vehicle 50. The distance measurement sensor 58 measures the distance (linear distance) to the ground ahead in the direction of travel. The distance measurement sensor 58 may emit a detection wave 90 such as a laser or millimeter wave, and measure the distance based on the reception of the reflected wave. Any measurement method may be used, and for example, a TOF (Time Of Flight) method may be used.

[0015] Distance measurement sensor 58 measures distance along a direction inclined with respect to the direction of gravity. That is, distance measurement sensor 58 emits detection waves 90 forward in the direction of travel of work vehicle 50. Distance measurement sensor 58 is attached at a height H and measures distance along a direction that forms an angle θ1 with the ground (horizontal plane).

[0016] As described above, since the work vehicle 50 can move forward and backward, the distance measurement sensors 58 may be attached to both the front and rear of the work vehicle 50. Furthermore, the distance measurement sensors 58 may be attached to both the left and right so that the planned travel locations of the left and right wheels 54 can be monitored.

[0017] FIG. 2 is a diagram showing an example of a control system including the control device 1. As shown in FIG.

[0018] The control device 1 is mounted on the work vehicle 50. However, in a modified example, the control device 1 may be in the form of, for example, a server computer. In this case, the control device 1 and the various other components shown in FIG. 2 may be able to communicate with each other via a wireless network.

[0019] The control device 1 is connected to the distance measurement sensor 58 described above.

[0020] A cancel switch 5 is connected to the control device 1. The cancel switch 5 may be disposed on the main body of the work vehicle 50. The cancel switch 5 is operated to cancel the alarm function, which will be described later.

[0021] The control device 1 is connected to a travel motor 18 and an alarm output device 19.

[0022] The traction motor 18 generates power to drive the wheels 54. The traction motor 18 may be provided for each wheel 54, or may be connected to the left and right wheels 54 via a differential mechanism.

[0023] The alarm output device 19 outputs an alarm through sound and / or light. The alarm output device 19 may be in the form of, for example, a patrol lamp.

[0024] FIG. 3 is a functional block diagram showing the functions of the control device 1. As shown in FIG.

[0025] The control device 1 includes a normal control unit 148, a distance acquisition unit 150, a parameter calculation unit 152, an avoidance object detection unit 154, an avoidance processing unit 155, an invalidation unit 156, and a threshold setting unit 158. The normal control unit 148 to the threshold setting unit 158 ​​can be realized by the CPU of a computer that forms the control device 1 executing one or more programs in a storage device built into the computer that forms the control device 1 or in a storage device accessible by the computer.

[0026] The normal control unit 148 realizes various operations of the vehicle 50 based on various inputs from the user. For example, the normal control unit 148 drives the travel motor 18 to move the vehicle 50 based on a movement instruction input from the user. Furthermore, the normal control unit 148 drives an actuator (not shown) for the work platform 52 to raise the work platform 52 based on a lift instruction input from the user.

[0027] The distance acquisition unit 150 acquires distance information from the distance measurement sensor 58. In a modified example, the distance acquisition unit 150 may calculate the distance related to the distance information based on a sensor signal from the distance measurement sensor 58. In this embodiment, the distance of the distance information is the distance L1 from the distance measurement sensor 58 to the ground, as shown in FIG. 4, and has a relationship of H=L1 sin θ1 between the height H and the angle θ1 described above. Since the angle θ1 is constant, the distance L1 is always approximately constant when traveling on level ground.

[0028] In a modified example, the distance acquisition unit 150 may implement part or all of the distance calculation function of the distance measurement sensor 58.

[0029] The parameter calculation unit 152 calculates the value of one or more predetermined parameters related to the unevenness of the ground ahead of the vehicle in the traveling direction, based on the distance L1, height H, and angle θ1. In this embodiment, the predetermined parameter may be a parameter related to at least one of steps, walls, slopes, and holes that may exist on the ground. In this embodiment, as an example, the predetermined parameter is the depth D of the step, as shown in FIG. 5, and is calculated based on the following formula: Depth D=L1sinθ1-H Here, H and θ1 are fixed values, and L1 is a distance based on distance information from the distance measurement sensor 58. In another embodiment, the predetermined parameter may be the width W1 of the step (length in the traveling direction). In this case, the width W1 may be calculated as follows. Width W1 = L1 cos θ1 - H / tan θ1 Note that the width W1 here represents the width of the step in the direction of travel that is detected at that time, and therefore the actual width of the step is greater than or equal to width W1.

[0030] The object to be avoided detection unit 154 detects at least one of a step, a wall, a slope, and a hole as an object to be avoided ahead of the vehicle 50 in the traveling direction, based on the calculated values ​​of the predetermined parameters by the parameter calculation unit 152.

[0031] For example, the object-to-be-avoided detection unit 154 may detect a step to be avoided when the depth D is equal to or greater than a threshold value Th1 (not shown). In this case, the threshold value Th1 may be adjusted taking into consideration the characteristics of the vehicle 50 (such as the size of the wheels 54, etc.).

[0032] The object-to-be-avoided detection unit 154 may also detect a slope to be avoided when the depth D increases as the vehicle 50 progresses (moves). In this case, the gradient of the slope may be calculated based on the amount of movement ΔL of the vehicle 50 and the amount of change in the depth D, and the slope to be avoided may be detected when the gradient of the slope is equal to or greater than a threshold. In this case, the amount of movement ΔL may be calculated based on the amount of rotation of the travel motor 18, etc. Alternatively, as shown in FIG. 7 , the gradient θ of the slope may be calculated based on distance information from multiple distance sensors 58 that emit detection waves 90 in different directions, and the slope to be avoided may be detected when the gradient of the slope is equal to or greater than a threshold.

[0033] Additionally, the object-to-be-avoided detection unit 154 may detect a hole to be avoided when the depth D becomes equal to or greater than threshold value Th1 as the vehicle 50 progresses (moves) and then returns to within threshold value Th1. In this case, for example, as shown in Figure 6, a hole to be avoided may be detected when the width W1 is equal to or greater than threshold value Th2. This is because a hole (the same applies to a groove) with a width W1 less than threshold value Th2 is likely to not impede the vehicle 50 from traveling. Here, in this embodiment, as described above, angle θ1 is an angle significantly smaller than 90 degrees. This makes it possible to detect holes or grooves with a relatively small width W1, even if they have the same depth as those on the right side, as shown on the left side of FIG. 6. In other words, it is possible to distinguish between holes or grooves that do not impede the travel of the vehicle 50 and holes or grooves that impede the travel of the vehicle 50 (i.e., objects to be avoided). From this perspective, as shown on the right side of FIG. 6, threshold value Th2 for width W1 may be adjusted by adjusting the mounting angle (angle θ1) of distance sensor 58 in relation to threshold value Th1 for depth D, or by taking into account the characteristics of the vehicle 50. For example, angle θ1 may be adjusted to have the following relationship with threshold value Th2 for width W1 and threshold value Th1 for depth D: θ1 ≈ arctan(Th1 / Th2).

[0034] 8, the object-to-be-avoided detection unit 154 may detect a wall or protrusion as an object to be avoided when the depth D<0 and its magnitude (=|D|) is equal to a threshold value Th3. Threshold value Th3 may be adapted taking into account the characteristics of the work vehicle 50 so that a protrusion that can be overcome by the work vehicle 50 is not detected as a protrusion to be avoided.

[0035] The above-described various thresholds Th1, Th2, etc. may be adjustable (customizable) by the user. Furthermore, the various thresholds Th1, Th2, etc. may be set in multiple stages. For example, the threshold Th1 may include a first threshold and a second threshold that is stricter than the first threshold. In this case, the avoidance processing unit 155, which will be described later, may perform different processing when the depth D exceeds the first threshold and when it further exceeds the second threshold. For example, when the depth D exceeds the first threshold, only a warning may be output, and when it further exceeds the second threshold, the traveling motor 18 may be stopped.

[0036] When an object to be avoided is detected by the object to be avoided detection unit 154, the avoidance processing unit 155 performs various processes so that the vehicle 50 can avoid the object to be avoided. Specifically, the avoidance processing unit 155 performs at least one of alarm output control and intervention control related to the travel of the vehicle 50. For example, the avoidance processing unit 155 may output an alarm via the alarm output device 19. Alternatively, instead of or in addition to outputting an alarm, the avoidance processing unit 155 may stop the travel motor 18 to prevent further advancement (movement) of the vehicle 50. Note that if the vehicle 50 has a braking device, the avoidance processing unit 155 may activate the braking device to stop the vehicle 50.

[0037] The disabling unit 156 disables the function of the avoidance processing unit 155 based on input from the user via the cancel switch 5. For example, the disabling unit 156 may stop the alarm when the user presses the cancel switch 5 while the avoidance processing unit 155 is outputting an alarm. Alternatively, the disabling unit 156 may disable the processing of the avoidance processing unit 155 itself when the cancel switch 5 is in the on state.

[0038] The threshold setting unit 158 ​​changes the various thresholds Th1, Th2, etc. described above based on the height of the working platform 52 of the work vehicle 50. In this case, the threshold setting unit 158 ​​may change the thresholds Th1, Th2, etc. so that the thresholds Th1, Th2, etc. are more lenient when the working platform 52 is in an elevated state than when the working platform 52 is in a lowered state. In other words, the threshold setting unit 158 ​​may change the thresholds Th1, Th2, etc. so that the object to be avoided detection unit 154 is more likely to detect an object to be avoided when the working platform 52 is in an elevated state than when the working platform 52 is in a lowered state.

[0039] Next, an example of the operation of the control device 1 will be described with reference to FIG.

[0040] FIG. 9 is a flowchart showing an example of processing executed by the control device 1.

[0041] In step S900, the control device 1 acquires distance information from the distance measurement sensor 58.

[0042] In step S902, the control device 1 calculates predetermined parameters based on the distance information obtained in step S900. The predetermined parameters are as described above.

[0043] In step S904, the control device 1 determines whether or not an object to be avoided has been detected based on the calculated values ​​of the predetermined parameters obtained in step S902. The method for detecting an object to be avoided is as described above. If the determination result is "YES," the process proceeds to step S906; otherwise, the process for the current cycle ends.

[0044] In step S906, the control device 1 outputs an alarm via the alarm output device 19. The method for outputting the alarm may be as described above.

[0045] In step S908, the control device 1 determines whether the work vehicle 50 has stopped. For example, the control device 1 may determine whether a stop command has been input from the user. If the determination result is "YES", the process proceeds to step S914; otherwise, the process proceeds to step S910.

[0046] In step S910, the control device 1 determines whether the cancel switch 5 has been operated within a predetermined time from the time the alarm was output in step S906. If the determination result is "YES", the process proceeds to step S914; otherwise, the process proceeds to step S912.

[0047] In step S912, the control device 1 controls the travel motor 18 to stop the rotation of the wheels 54. That is, the control device 1 executes an automatic stop by intervention. Note that, when the vehicle stops, the control device 1 may stop the output of an alarm via the alarm output device 19.

[0048] In step S914, the control device 1 stops the alarm output via the alarm output device 19.

[0049] 9, the same processing is executed from step S906 onwards regardless of the type of object to be avoided, but this is not limiting. That is, the manner in which an alarm is output may be changed depending on the type of object to be avoided.

[0050] Although each embodiment has been described in detail above, it is not limited to the specific embodiment, and various modifications and changes are possible within the scope of the claims. It is also possible to combine all or a plurality of components of the above-described embodiments. [Explanation of symbols]

[0051] 1. Control device 5 Cancel switch 18 Travel motor 19 Alarm output device 50 Work vehicle 52 Work Platform 54 wheels 58 Distance measurement sensor 90 detection wave 148 Normal control section 150 Distance acquisition part 152 Parameter calculation unit 154 Avoidance object detection unit 155 Avoidance processing unit 156 Nullification Section 158 Threshold setting unit

Claims

1. A control device for a work vehicle that can travel on a travel surface, a distance acquisition unit that acquires, based on sensor information from a sensor attached to the work vehicle, distance information to the ground ahead in the traveling direction of the work vehicle, the distance along a predetermined direction from the sensor; a parameter calculation unit that calculates the value of one or more specified parameters related to the unevenness of the ground ahead in the direction of travel of the work vehicle based on the distance, the angle corresponding to the specified direction, and the mounting height of the sensor.

2. 2. The control device according to claim 1, further comprising an object to be avoided detection unit that detects at least one object to be avoided ahead in the traveling direction of the work vehicle, including a step, a wall, a protrusion, a slope, and a hole, based on the calculated values ​​of the one or more predetermined parameters.

3. the one or more predetermined parameters include a width or a depth of the step along a traveling direction of the work vehicle; 3. The control device according to claim 2, further comprising an avoidance processing unit that executes at least one of warning output control and intervention control regarding the travel of the work vehicle when the object to be avoided is detected by the object to be avoided detection unit.

4. The control device according to claim 3 , further comprising a disabling unit that disables a function of the avoidance processing unit based on an input from a user.

5. The work vehicle is an aerial work vehicle, the object-to-be-avoided detection unit detects the object to be avoided based on a relationship between the calculated value of the one or more predetermined parameters and a threshold value; The control device according to claim 3 , further comprising a threshold setting unit that changes the threshold based on the height of the work platform of the aerial work vehicle.

Images