Work vehicle control system

Abstract

To provide a work vehicle control device that can ensure safety and driving stability on inclines. [Solution] The work vehicle control device 10 according to the present disclosure includes a three-dimensional information acquisition unit 11 that acquires three-dimensional information of the road surface in the direction of travel, a response determination unit 51 that determines a location requiring action that exists in the direction of travel and where predetermined processing needs to be performed based on the three-dimensional information acquired by the three-dimensional information acquisition unit 11, and a control unit 52 that starts the predetermined processing and controls the work vehicle WV before entering or when entering a location requiring action determined by the response determination unit 51.

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a wheel loader that automatically controls the engine power output capacity according to the working state. When this wheel loader travels uphill on a slope, it selects a high-output mode. The vehicle body of this wheel loader is provided with an inclination angle detector for measuring the inclination angle in the longitudinal direction of the vehicle body, an accelerator opening detector for measuring the opening degree of the accelerator pedal, and an acceleration detector for measuring the acceleration of the vehicle, each of which is connected to a controller. When the vehicle is tilted at an inclination angle of a certain degree or more and is running, or when, despite the accelerator pedal being opened by a certain degree or more, a predetermined acceleration or more cannot be obtained, the controller determines that the vehicle is traveling uphill.

[0003] Patent Document 2 discloses a wheel loader capable of suppressing pitching of the vehicle body regardless of the vehicle speed. This wheel loader includes an obstacle sensor (such as a millimeter-wave radar or a camera) for measuring the distance to an obstacle, and the obstacle sensor transmits obstacle information indicating that an obstacle has been detected and the distance to the obstacle to a controller. When the distance between the obstacle and the vehicle body is equal to or less than a predetermined distance, the obstacle determination unit of the controller transmits an automatic brake instruction signal to the brake control unit and transmits an alarm instruction signal to the alarm unit.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the wheel loader (work vehicle) described in Patent Document 1, a high-power mode is selected when it is determined that the vehicle is traveling uphill on an incline. However, since the control is performed to increase the speed only after the speed has decreased and uphill travel has been detected, it is inefficient and the change in speed reduces driving stability. Furthermore, because the control is performed only after uphill travel has been detected, in the case of an automatically controlled work vehicle, if the incline angle of the incline exceeds the climbing ability of the work vehicle, it may become impossible to travel after entering the incline, and the work vehicle may come to an emergency stop on the incline.

[0006] Furthermore, while the wheel loader (work vehicle) described in Patent Document 2 detects obstacles on the road, it is difficult to detect recesses in the road surface, making it difficult to ensure safety.

[0007] Therefore, this disclosure aims to provide a work vehicle control device that can ensure safety and driving stability on ramps. [Means for solving the problem]

[0008] To solve the above problems, a work vehicle control device according to a first aspect of the present invention comprises: a three-dimensional information acquisition means for acquiring three-dimensional information of the road surface in the direction of travel; a response determination means for determining a location requiring action that exists in the direction of travel and where a predetermined process needs to be performed, based on the three-dimensional information acquired by the three-dimensional information acquisition means; and a control means for initiating the predetermined process and controlling the work vehicle before or upon entering the location requiring action determined by the response determination means.

[0009] A second aspect of the present invention is a work vehicle control device according to the first aspect, wherein the location to be addressed includes a ramp, the predetermined process includes a process corresponding to the angle of the ramp obtained from the three-dimensional information, and the control means, if the angle of the ramp is a steep ramp greater than a predetermined angle, starts a process to avoid entering the steep ramp before entering the steep ramp.

[0010] A third aspect of the present invention is a work vehicle control device according to the second aspect, wherein the control means initiates a process to restrict a predetermined operation of the work vehicle before or when entering the ramp, if the angle of the ramp is not that of a steep ramp.

[0011] A fourth aspect of the present invention is a work vehicle control device according to the first or second aspect, wherein the location requiring attention includes a recess that the work vehicle cannot pass through, the predetermined process includes a process to avoid the recess, and the control means starts the process to avoid entering the recess before entering the recess. [Effects of the Invention]

[0012] This disclosure provides a work vehicle control device that can ensure safety and driving stability on ramps. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic overall configuration diagram of an automated driving system to which a work vehicle control device according to one embodiment of the present invention is applied. [Figure 2] This is an explanatory diagram showing an example of a hardware configuration. [Figure 3] This is a block diagram of a work vehicle, including the work vehicle control device. [Figure 4] This diagram illustrates the control process for work vehicles, where (a) shows the case where the location requiring attention is a ramp, and (b) shows the case where the location requiring attention is an impassable recess. [Figure 5] This is a flowchart of the work vehicle control process. [Modes for carrying out the invention]

[0014] One embodiment of the present invention will be described below with reference to the drawings.

[0015] Figure 1 is a schematic overall configuration diagram of an automated driving system to which a work vehicle control device according to one embodiment of the present invention is applied. Figure 2 is an explanatory diagram showing an example of the hardware configuration. Figure 3 is a block diagram of a work vehicle including the work vehicle control device. Figure 4 is an explanatory diagram of the work vehicle control process, where (a) shows the case where the location requiring attention is a ramp, and (b) shows the case where the location requiring attention is an impassable recess. The dashed line in Figure 4 schematically shows the measurement range of the 3D-LiDAR.

[0016] As shown in Figure 1, the work vehicle control device 10 according to one embodiment of the present invention is mounted on a work vehicle WV. The work vehicle control device 10 is a device that detects locations in the direction of travel of the work vehicle WV that require action (hereinafter referred to as "locations requiring action") and executes processing according to the detected locations requiring action. In other words, "locations requiring action" means locations that exist in the direction of travel of the work vehicle WV and where predetermined processing needs to be performed in order to ensure safety.

[0017] (Work vehicles) The work vehicle WV of this embodiment is a vehicle capable of automatic driving control based on input instructions (such as work location and destination) from a terminal 1 connected via a network NW. That is, the work vehicle WV is equipped with various sensors (not shown) and automatic control devices (not shown) necessary for automatic driving control. For example, the work vehicle WV is equipped with a location information acquisition means that acquires the location information (latitude, longitude, and altitude) of the work vehicle WV. Examples of location information acquisition means include GPS (Global Positioning System) and GNSS (Global Navigation Satellite System).

[0018] A work vehicle WV is a vehicle used for performing work, for example, at a construction site, and its type is not particularly limited. In this embodiment, a wheel loader will be used as the work vehicle WV. Terminal 1 may be an information processing device installed in a management center, or it may be a portable terminal (information processing device) that can be carried around.

[0019] As shown in FIG. 1, the wheel loader (work vehicle WV) has an articulated vehicle body in which a front body FB and a rear body RB are connected by a center pin (not shown). The front body FB and the rear body RB are connected via the center pin so as to be bendable left and right. The front body FB is provided with left and right front wheels fw, and the rear body RB is provided with left and right rear wheels rw. A bucket b is attached to the front body FB via left and right arms a. The rear body RB is equipped with an engine (not shown) and the like for generating power to drive the work vehicle WV. Further, the rear body RB is provided with a cab c for an operator or the like to board.

[0020] As shown in FIG. 2, the work vehicle WV includes a work vehicle control device 10, a drive system device 20 for driving the work vehicle WV, a braking system device 30 for braking the work vehicle WV, and a steering system device 40 for steering the work vehicle WV. Further, the work vehicle WV of the present embodiment includes a work system device (not shown) such as a hydraulic cylinder for controlling the left and right arms a, the bucket b, and the like.

[0021] The drive system device 20 includes various devices (engine, transmission, differential device, etc., not shown) for transmitting the power of the engine to the left and right front wheels fw and rear wheels rw. The braking system device 30 includes various devices (brake hydraulic pump, brake device, etc., not shown) for braking the work vehicle WV. The steering system device 40 includes various devices (steering hydraulic pump, etc.) for steering the work vehicle WV by bending the articulated vehicle body. The drive system device 20, the braking system device 30, and the steering system device 40 are controlled by a controller 50 (described later) of the work vehicle control device 10. Note that the drive system device 20, the braking system device 30, and the steering system device 40 may be manually controllable by an operator operating pedals, levers, a steering wheel, etc. (not shown) provided in the cab c.

[0022] <Work Vehicle Control Device> The work vehicle control device 10 comprises a three-dimensional information acquisition unit (three-dimensional information acquisition means) 11 and a controller 50. In addition to the above, the work vehicle control device 10 of this embodiment is equipped with a tilt sensor 12 that detects the tilt angle of the work vehicle WV in the front-rear direction relative to the horizontal. The tilt sensor 12 sequentially transmits the acquired information to the controller 50.

[0023] (3D information acquisition department) The three-dimensional information acquisition unit 11 is a device for detecting locations requiring attention in the direction of travel of the work vehicle WV (including not only forward but also reverse movement; the same applies hereinafter). The three-dimensional information acquisition unit 11 acquires information on the road surface in the direction of travel of the work vehicle WV and transmits it sequentially to the controller 50 of the work vehicle control device 10.

[0024] In this embodiment, a 3D-LiDAR (Light Detection and Ranging) is used as the three-dimensional information acquisition unit 11. The 3D-LiDAR, acting as the three-dimensional information acquisition unit 11, acquires information on the road surface in the direction of travel of the work vehicle WV as three-dimensional point cloud data (three-dimensional information). Each point in the three-dimensional point cloud data acquired by the 3D-LiDAR is defined by X, Y, and Z coordinates. The controller 50 can acquire a three-dimensional image of the road surface in the direction of travel of the work vehicle WV based on the three-dimensional point cloud data acquired by the 3D-LiDAR (three-dimensional information acquisition unit 11).

[0025] (controller) As shown in Figure 2, the controller 50 is a computer or other calculation device and comprises a response determination unit (response determination means) 51 and a control unit (control means) 52 that controls the work vehicle WV.

[0026] (Hardware configuration) As shown in Figure 3, the controller 50 includes a communication unit H1, an input unit H2, a display unit H3, a storage unit H4, and a processor H5, which are connected via a bus H6 for access. Note that this hardware configuration is just one example, and it can be implemented with other hardware.

[0027] The communication unit H1 is a communication interface that establishes a communication route with other devices and performs data transmission and reception, such as a network interface or a wireless interface. In this embodiment, the communication unit H1 of the controller 50 is connected to the terminal 1 via a network NW so that they can communicate with each other. The network may be a closed network or an open network.

[0028] The input unit H2 is a device that accepts various types of information, such as a mouse or keyboard.

[0029] The display unit H3 is a display unit such as a monitor (display) that displays various information. If the monitor is a touch panel monitor that can accept input, the monitor may have the function of an input unit H2 in addition to the function of a display unit H3.

[0030] The memory unit H4 is a storage device that stores data and programs for executing various functions of the controller 50. Examples of memory units H4 include ROM (Read Only Memory), RAM (Random Access Memory), and hard disks.

[0031] The processor H5 controls each process in the controller 50 using programs and data stored in the memory unit H4. Examples of processor H5 include a CPU (Central Processing Unit) and an MPU (Micro Processing Unit). This processor H5 loads programs stored in ROM, etc., into RAM and executes various processes for each operation. Specifically, the processor H5 functions as a response determination unit (response determination means) 51 and a control unit (control means) 52 by executing programs stored in the memory unit H4. Alternatively, some of the functions of the processor H5 may be extracted and provided in other information processing devices (e.g., terminal 1), and each process may be executed using multiple information processing devices.

[0032] (Action Required Determination Unit) The action-requiring determination unit 51 shown in Figure 2 determines action-requiring locations that exist in the direction of travel and require the execution of predetermined processes, based on the three-dimensional information acquired by the three-dimensional information acquisition unit 11. In addition, the action-requiring determination unit 51, by determining action-requiring locations, can also determine locations that exist in the direction of travel and do not require the execution of the predetermined processes (or where the predetermined processes may be completed) (hereinafter referred to as "no-action locations"), based on the three-dimensional information acquired by the three-dimensional information acquisition unit 11. For example, no-action locations may be detected by not detecting action-requiring locations. Examples of no-action locations include flat road surfaces with little or no slope.

[0033] (Locations requiring action) As shown in Figure 4, examples of locations requiring attention include ramps 2 (including both uphill and downhill ramps; the same applies hereinafter) located in the direction of travel, and recesses 3 on the road surface that prevent the work vehicle WV from passing (hereinafter referred to as "impassable recesses 3"). Locations requiring attention include at least one of ramps 2 and impassable recesses 3. Locations requiring attention may also include other locations requiring attention that are different from ramps 2 and impassable recesses 3 (for example, obstacles protruding from the road surface).

[0034] (Prescribed procedures on ramps) As shown in Figure 4(a), if the location requiring attention includes the ramp 2, the predetermined process described above includes processing according to the angle θ (angle relative to the horizontal) of the ramp 2 obtained from the three-dimensional information acquired by the three-dimensional information acquisition unit 11. That is, the location requiring attention determination unit 51 detects the angle θ of the ramp 2 from the angle of the work vehicle WV and the three-dimensional information acquired by the three-dimensional information acquisition unit 11, and determines whether or not it is a location requiring attention according to the detected angle θ. Note that in Figure 4(a), the case of a downward ramp is illustrated with a dashed line.

[0035] For example, the above-described predetermined process may be a process to avoid entering a steep slope if the angle θ of the ramp 2 is greater than the first angle (predetermined angle) θ1 (θ>θ1). The process to avoid entering a steep slope means a process to prevent the work vehicle WV from entering the steep slope, and includes processes to have the work vehicle WV travel around the steep slope or to stop the work vehicle WV. The first angle θ1 can be, for example, the maximum climbing ability (angle) set for the work vehicle WV, or an angle that is smaller than the maximum climbing ability but still ensures safety. In this way, the action required determination unit 51 may determine that a ramp 2 (steep slope) where it is necessary to perform an action to avoid entry is a location requiring action.

[0036] Furthermore, the above-described predetermined process may also be a process that restricts predetermined actions of the work vehicle WV when the angle θ of the ramp 2 is not a steep ramp (θ ≤ θ1). Examples of the predetermined actions to be restricted include driving at a speed above a predetermined speed, driving laterally or diagonally on the ramp 2, driving in a gear other than low speed, and driving at an engine speed above a predetermined speed. When restricting these actions, the range of the angle θ of the ramp 2 may have not only an upper limit (first angle θ1) but also a lower limit (second angle θ2). In other words, the above-described predetermined process may also be a process that restricts predetermined actions of the work vehicle WV when the angle θ of the ramp 2 is not a steep ramp (θ2 ≤ θ ≤ θ1). In this way, the action requirement determination unit 51 may determine that a ramp 2 that requires the execution of the above-described predetermined actions is an action requirement location. Note that the predetermined actions to be restricted are not limited to those described above, and various actions that would reduce safety if performed on the ramp 2 can be applied.

[0037] Furthermore, the above-described predetermined process may also be a process to maintain the current travel speed of the work vehicle WV when it enters ramp 2, provided that the angle θ of ramp 2 is not a steep ramp (θ ≤ θ1) and is smaller than the second angle θ2 (θ < θ2). In this way, the action required determination unit 51 may determine ramp 2 (ramp 2 with an angle smaller than the second angle θ2) as an action required location where it is necessary to perform a process to maintain the travel speed. Note that if the angle θ of ramp 2 is small enough that safety can be ensured even if the above-described predetermined operation is performed, it is not necessary to determine that ramp 2 as an action required location where the predetermined process needs to be performed.

[0038] (Prescribed procedures in impassable recesses) As shown in Figure 4(b), if the location requiring attention includes an impassable recess 3, the above-mentioned predetermined process includes a process to avoid the impassable recess 3. The process to avoid the impassable recess 3 means a process to prevent the work vehicle WV from entering the impassable recess 3, and includes a process to have the work vehicle WV drive around the impassable recess 3 or a process to stop the work vehicle WV. In other words, when the attention requirement determination unit 51 detects a recess (for example, a decrease in the number of points in the point cloud) in the direction of travel from the three-dimensional information acquired by the three-dimensional information acquisition unit 11, it determines whether or not it is an impassable recess (impassable recess 3) based on the specifications of the work vehicle WV (including its size) stored in advance, and determines whether or not it is a location requiring attention. In this way, the attention requirement determination unit 51 may determine an impassable recess 3 that requires a process to avoid entry as a location requiring attention.

[0039] (Control Unit) The control unit 52 shown in Figure 2 controls the work vehicle WV by initiating the predetermined processing corresponding to the location requiring action, either before or upon entering the location requiring action determined by the action determination unit 51. Specifically, the control unit 52 controls the drive system 20, braking system 30, steering system 40, etc., of the work vehicle WV.

[0040] For example, if the predetermined process described above is a process to avoid a location requiring attention (ramp 2 (steep ramp) or impassable recess 3), the control unit 52 controls the drive system 20, braking system 30, steering system 40, etc., before entering the location requiring attention, and executes a process to avoid the work vehicle WV entering ramp 2 (steep ramp) or impassable recess 3.

[0041] Furthermore, if the above-mentioned predetermined process is a process that restricts the above-mentioned predetermined operation of the work vehicle WV, the control unit 52 controls the drive system 20, braking system 30, steering system 40, etc., before or when entering the area requiring attention, and executes the process so that the above-mentioned predetermined operation is restricted at least when the work vehicle WV enters the area requiring attention. The process that restricts the above-mentioned predetermined operation is not limited to a process that restricts one of the above-mentioned predetermined operations, but may be a process that restricts multiple operations. In addition, if the work vehicle WV is a backhoe or the like having a lower traveling body such as a crawler and an upper slewing body equipped with an arm, bucket, etc., the control unit 52 may control the slewing device between the lower traveling body and the upper slewing body. In this case, the control unit 52 may restrict the slewing of the upper slewing body (the above-mentioned predetermined operation) before or when entering the area requiring attention, or it may restrict the operation (the above-mentioned predetermined operation) or state of the upper slewing body being sideways with respect to the direction of travel of the lower traveling body.

[0042] Furthermore, if the action requirement determination unit 51 detects a location that does not require action in the direction of travel while the vehicle is traveling on the ramp 2, the control unit 52 may execute a process to release the restriction on the predetermined operation (restriction termination process) when entering or immediately before entering the location that does not require action.

[0043] (Work vehicle control processing) Next, the work vehicle control process performed by the work vehicle control device 10 will be explained based on Figure 5. Figure 5 is a flowchart of the work vehicle control process. This process is executed repeatedly.

[0044] As shown in Figure 5, in the work vehicle control process, first, the three-dimensional information acquisition unit 11 acquires three-dimensional information of the road surface in the direction of travel of the work vehicle WV and transmits it to the controller 50 (step S1).

[0045] Next, the action-requiring determination unit 51 determines, based on the three-dimensional information acquired by the three-dimensional information acquisition unit 11, which locations in the direction of travel require action and in which predetermined processing needs to be performed (step S2).

[0046] If the action required determination unit 51 determines that the impassable recess 3 is an action required location (step S2: YES1), the control unit 52 executes a process to prevent the work vehicle WV from entering the impassable recess 3 before entering it (step S3), and then terminates this process.

[0047] If the action required determination unit 51 determines that ramp 2 is an action required location (step S2: YES2), it determines whether ramp 2 is a steep ramp (step S4).

[0048] If the action required determination unit 51 determines that it is a steep slope (step S4: YES), the control unit 52 executes a process to prevent the work vehicle WV from entering the steep slope before entering it (step S5), and then terminates this process. On the other hand, if the action required determination unit 51 determines that it is not a steep slope (step S4: NO), the control unit 52 executes a process to restrict the above-mentioned predetermined operation before or when entering the slope 2 (step S6), and then terminates this process.

[0049] In step S2, if the action required determination unit 51 does not detect an action required location in the direction of travel (i.e., it detects an action not required location) (step S2: NO), the process proceeds to step S7. In step S7, the control unit 52 determines whether or not restriction processing is in progress (restriction processing in step S6), and if it determines that restriction processing is not in progress (step S7: NO), the process ends. On the other hand, if the control unit 52 determines in step S7 that restriction processing is in progress (step S7: YES), it executes restriction termination processing to release the restriction of the predetermined operation when entering or immediately before entering an action not required location (step S8), and then terminates the process. Note that the determination of whether or not restriction processing is in progress (restriction processing in step S6) can be made based on a flag, for example, by setting a flag indicating that restriction processing is in progress when performing the restriction processing in step S6.

[0050] In the work vehicle control device 10 configured as described above, the three-dimensional information acquisition unit 11 acquires three-dimensional information of the road surface in the direction of travel, so it can detect the angle of the ramp on the road surface in the direction of travel. Furthermore, because the three-dimensional information acquisition unit 11 acquires three-dimensional information of the road surface in the direction of travel, it can detect not only obstacles protruding from the road surface in the direction of travel, but also recesses. The control unit 52 then starts the predetermined processing described above to control the work vehicle before or when entering a location requiring attention. In other words, it can detect locations requiring attention before entering them, and execute control according to the location before or when entering such locations, so it is possible to avoid entering locations that should not be entered, or at least execute control according to the location when entering such locations.

[0051] For example, unlike control that increases speed when a speed reduction occurs upon entering an incline, this system can prevent a speed reduction when entering an incline, thus suppressing speed changes and ensuring driving stability. Furthermore, it can avoid areas requiring attention before entering them, thus avoiding emergency stops at those areas and ensuring safety. In addition, it can detect not only obstacles protruding from the road surface in the direction of travel but also recesses, allowing the work vehicle WV to avoid impassable recesses 3 before entering them, thus ensuring safety.

[0052] Thus, according to this embodiment, it is possible to provide a work vehicle control device 10 that can ensure safety and driving stability on ramps.

[0053] Furthermore, if the response determination unit 51 detects a location that does not require response in the direction of travel while the vehicle is traveling on the ramp 2 (during the restriction process), the control unit 52 may execute the restriction termination process when entering or immediately before entering the location that does not require response. This allows the end of the ramp 2 to be determined in advance, and the restriction process to be terminated at or before the end of the ramp 2, allowing the vehicle to return to normal operation or to perform driving control according to the flat road surface, thereby ensuring driving stability after climbing (or descending) the ramp 2.

[0054] Although the present invention has been described above based on the above embodiments, the present invention is not limited to the contents of the above embodiments, and can naturally be modified as appropriate without departing from the present invention. In other words, all other embodiments, examples, and operational techniques made by those skilled in the art based on these embodiments are of course included in the scope of the present invention. [Explanation of Symbols]

[0055] 2: Ramp 3: Impassable recess (recess) 10: Work vehicle control device 11: Three-dimensional information acquisition unit (three-dimensional information acquisition means) 50: Controller 51: Action Required Determination Unit (Action Required Determination Means) 52: Control unit (control means) WV: Work Vehicle

Claims

1. A means for acquiring three-dimensional information of the road surface in the direction of travel, A means for determining locations requiring action that exist in the direction of travel and require predetermined processing, based on the three-dimensional information acquired by the three-dimensional information acquisition means, The system includes a control means that controls the work vehicle by initiating the predetermined process before or upon entering the location requiring action, as determined by the action-requiring determination means. A work vehicle control device characterized by the following features.

2. The aforementioned locations requiring attention include ramps, The predetermined processing includes processing according to the angle of the ramp obtained from the three-dimensional information, The control means, if the slope is steeper than a predetermined angle, starts a process to avoid entering the slope before entering it. The work vehicle control device according to feature 1.

3. The control means, if the angle of the ramp is not that of a steep ramp, initiates a process to restrict predetermined movements of the work vehicle before or during entry onto the ramp. The work vehicle control device according to feature 2.

4. The aforementioned location requiring attention includes a recess that the work vehicle cannot pass through, The predetermined process includes a process to avoid the recess, The control means initiates a process to avoid entering the recess before entering the recess. A work vehicle control device according to claim 1 or 2.

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