Obstacle detection device and driving control device

Abstract

To provide an obstacle detection device and a traveling control device capable of suppressing a false detection of an obstacle even if an actual travel route is deviated from a planned travel route.SOLUTION: An obstacle detection device 30 comprises a route generation unit 32 for acquiring a planned travel route R of a forklift 1 formed by multiple path points P, a detection area setting unit 35, and an obstacle determination unit 37, where the detection area setting unit sets an obstacle detection area E for detecting an obstacle X existing in the traveling direction of the forklift 1 by mapping a detection frame F enclosing the forklift 1 as a whole to the path point P of the planned travel route R acquired by the route generation unit 32, and the obstacle determination unit determines whether or not the obstacle X exists in the obstacle detection area E set by the detection area setting unit 35 based on an obstacle detection sensor 23 for detecting the obstacle X and point group data of the obstacle sensor 23.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an obstacle detection device and a driving control device. [Background technology]

[0002] Known conventional driving control devices include, for example, the technology described in Patent Document 1. The driving control device described in Patent Document 1 includes a vehicle ECU that controls the driving of a work vehicle, an autonomous driving ECU that calculates the work vehicle's own position based on a positioning signal received by a GPS antenna, compares the self-position with a planned driving route, and transmits a control signal to the vehicle ECU, and an obstacle sensor that detects the presence or absence of an obstacle ahead of the work vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-97454 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in unmanned autonomous driving, the planned driving route may differ from the actual driving route. In this case, an obstacle may be mistakenly detected as being ahead of the work vehicle, causing the work vehicle to stop.

[0005] An object of the present invention is to provide an obstacle detection device and a driving control device that can suppress erroneous detection of an obstacle even if the planned driving route and the actual driving route deviate from each other. [Means for solving the problem]

[0006] (1) An obstacle detection device according to one aspect of the present invention includes a route acquisition unit that acquires a planned travel route for an industrial vehicle formed by a plurality of route points; a detection area setting unit that sets an obstacle detection area for detecting obstacles present in the direction of travel of the industrial vehicle by mapping a detection frame that entirely surrounds the industrial vehicle to the route points of the planned travel route acquired by the route acquisition unit; an obstacle detection unit that detects obstacles; and an obstacle determination unit that determines whether an obstacle is present in the obstacle detection area set by the detection area setting unit based on detection data from the obstacle detection unit.

[0007] In such an obstacle detection device, a planned travel route for an industrial vehicle formed by multiple route points is acquired. Then, a detection frame that entirely surrounds the industrial vehicle is mapped to the route points of the planned travel route, thereby setting an obstacle detection area for detecting obstacles present in the direction of travel of the industrial vehicle. Then, based on detection data from an obstacle detection unit that detects obstacles, it is determined whether an obstacle exists in the obstacle detection area. Therefore, even if the actual travel route of the industrial vehicle deviates from the planned travel route, if an obstacle exists in the obstacle detection area obtained from the multiple detection frames, the obstacle is detected as existing in the direction of travel of the industrial vehicle. This reduces erroneous detection of obstacles even if the planned travel route and the actual travel route deviate.

[0008] (2) In (1), the dimensions of the detection frame may be larger in the front-rear and left-right directions than the external dimensions of the industrial vehicle. In this configuration, the dimensions of the detection frame have margins in the front-rear and left-right directions relative to the external dimensions of the industrial vehicle, so a large obstacle detection area is set. Therefore, regardless of errors that occur when the industrial vehicle travels along the planned travel route, it is possible to accurately detect whether an obstacle exists in the direction of travel of the industrial vehicle.

[0009] (3) In (1) or (2), the industrial vehicle may have multiple types of detachable implements that differ in size in at least one of the longitudinal and lateral directions of the industrial vehicle, and the detection area setting unit may map detection frames with different sizes depending on the type of implement. In this configuration, appropriate detection frames are mapped to route points on the planned travel route depending on the type of implement used. Therefore, even when multiple types of implements are used, erroneous detection of obstacles is suppressed.

[0010] (4) In any of (1) to (3), the obstacle detection device may further include a removal processing unit that removes portions corresponding to objects other than obstacles from the detection data of the obstacle detection unit, and the obstacle determination unit may determine whether an obstacle is present in the obstacle detection area based on the processed data from which the portions corresponding to objects other than obstacles have been removed by the removal processing unit. In this configuration, the portions corresponding to objects other than obstacles are removed from the detection data of the obstacle detection unit, thereby further suppressing erroneous detection of an obstacle.

[0011] (5) A driving control device according to another aspect of the present invention includes a drive unit that drives an industrial vehicle, a route acquisition unit that acquires a planned driving route for the industrial vehicle formed by a plurality of route points, a first control unit that controls the drive unit to drive the industrial vehicle along the planned driving route, a detection area setting unit that sets an obstacle detection area for detecting obstacles present in the direction of travel of the industrial vehicle by mapping a detection frame that entirely surrounds the industrial vehicle to the route points of the planned driving route acquired by the route acquisition unit, an obstacle detection unit that detects obstacles, an obstacle determination unit that determines whether an obstacle exists in the obstacle detection area set by the detection area setting unit based on detection data from the obstacle detection unit, and a second control unit that controls the drive unit to slow down or stop the industrial vehicle when the obstacle determination unit determines that an obstacle exists in the obstacle detection area.

[0012] In such a driving control device, a planned driving route for the industrial vehicle formed by multiple route points is acquired. Then, a detection frame that entirely surrounds the industrial vehicle is mapped to the route points of the planned driving route, thereby setting an obstacle detection area for detecting obstacles present in the direction of travel of the industrial vehicle. Then, based on detection data from an obstacle detection unit that detects obstacles, it is determined whether an obstacle exists in the obstacle detection area. Therefore, even if the actual driving route of the industrial vehicle deviates from the planned driving route, if an obstacle exists in the obstacle detection area obtained from the multiple detection frames, the obstacle is detected as existing in the direction of travel of the industrial vehicle. This reduces erroneous detection of an obstacle even if the planned driving route and the actual driving route deviate.

[0013] (6) In (5), the second control unit may control the drive unit to stop the industrial vehicle when the distance to the obstacle is equal to or less than a specified value, and may control the drive unit to decelerate the industrial vehicle when the distance to the obstacle is longer than the specified value. In this configuration, when an obstacle is detected in the traveling direction of the industrial vehicle, the traveling state of the industrial vehicle is appropriately controlled according to the distance from the industrial vehicle to the obstacle. [Effects of the Invention]

[0014] According to the present invention, even if the planned driving route and the actual driving route deviate from each other, erroneous detection of an obstacle can be suppressed. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a perspective view showing a forklift as an industrial vehicle equipped with an obstacle detection device and a travel control device according to an embodiment of the present invention. [Figure 2] 1 is a block diagram showing the configuration of a cruise control device according to a first embodiment of the present invention. [Figure 3] FIG. 2 is a plan view showing an example of a planned travel route of a forklift. [Figure 4] 3 is a flowchart showing the procedure of a guidance control process executed by a guidance control unit shown in FIG. 2. [Figure 5] 3 is a flowchart showing the procedure of a detection area setting process executed by a detection area setting unit shown in FIG. 2. [Figure 6] 3 is a diagram showing an example of an obstacle detection area set by a detection area setting unit shown in FIG. 2. FIG. [Figure 7] 7 is a diagram showing the dimensional relationship between a detection frame that forms the obstacle detection area shown in FIG. 6 and a forklift. FIG. [Figure 8] 3 is a flowchart showing a procedure of a deceleration / stop control process executed by a deceleration / stop control unit shown in FIG. 2. [Figure 9] FIG. 10 is a schematic plan view illustrating, as a comparative example, how an obstacle is erroneously detected when an obstacle detection area is set based on the actual position of a forklift. [Figure 10] 3 is a schematic plan view showing an operating state of the obstacle detection device shown in FIG. 2 when the position of the forklift deviates from the planned travel route. [Figure 11] FIG. 4 is a block diagram showing the configuration of a cruise control device according to a second embodiment of the present invention. [Figure 12] FIG. 10 is a plan view showing a state in which a pallet is loaded using normal forks and a state in which a pallet is unloaded using long forks. [Figure 13] 12 is a flowchart showing the procedure of a detection area setting process executed by a detection area setting unit shown in FIG. 11. [Figure 14] FIG. 2 is a diagram showing a detection frame for a normal fork and a detection frame for a long fork, together with the dimensional relationship with a forklift. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or equivalent elements are designated by the same reference numerals, and redundant explanations will be omitted.

[0017] Fig. 1 is a perspective view showing a forklift as an industrial vehicle equipped with an obstacle detection device and a travel control device according to an embodiment of the present invention. In Fig. 1, the forklift 1 is an industrial vehicle used for loading and unloading. The forklift 1 is equipped with a traveling device 2 and a loading device 3 arranged in front of the traveling device 2.

[0018] The traveling device 2 has a body 4, front wheels 5 which are a pair of left and right drive wheels arranged at the front of the body 4, and rear wheels 6 which are a pair of left and right steerable wheels arranged at the rear of the body 4.

[0019] The cargo handling device 3 has a mast 7 attached to the front end of the vehicle body 4, a pair of left and right forks 9 attached to the mast 7 via lift brackets 8 so that they can be raised and lowered, a lift cylinder 10 that raises and lowers the forks 9, and a tilt cylinder 11 that tilts the mast 7. The forks 9 are working tools that hold a pallet 12 (see Figure 3). The forks 9 are detachably attached to the lift brackets 8.

[0020] The pallet 12 is, for example, a flat pallet made of plastic or wood. The pallet 12 has a rectangular shape in plan view. A cargo (not shown) is placed on the pallet 12. The pallet 12 is provided with a pair of fork holes 13 on the left and right, into which the forks 9 are inserted.

[0021] Fig. 2 is a block diagram showing the configuration of a travel control device according to a first embodiment of the present invention. The travel control device 20 of this embodiment is a device that controls the forklift 1 to automatically travel to an unloading position when unloading a pallet 12, as shown in Fig. 3, for example. The unloading position is a position where the forks 9 can be inserted into the fork holes 13 of the pallet 12. The travel control device 20 is mounted on the forklift 1.

[0022] In FIG. 2, the cruise control device 20 includes a laser sensor 21, a map storage unit 22, an obstacle sensor 23, a vehicle speed sensor 24, a drive unit 25, an alarm 26, and a controller 27.

[0023] The laser sensor 21 emits a laser beam toward the periphery of the forklift 1 and receives the reflected laser beam to detect the distance to objects present around the forklift 1 and acquire point cloud data. The point cloud is a collection of reflected points of the laser beam. Objects present around the forklift 1 include the pallet 12. For example, a LIDAR (light detection and ranging) or a laser range finder may be used as the laser sensor 21.

[0024] The map storage unit 22 stores map data of an area where cargo handling work is performed by the forklift 1. The map data includes pillars, shelves, walls, and the like.

[0025] The obstacle sensor 23 is an obstacle detection unit that detects an obstacle X (see FIG. 6) that exists around the forklift 1. The obstacle X may be a worker, another vehicle, or the like. As with the laser sensor 21, the obstacle sensor 23 may be a LIDAR or a laser range finder. The number of obstacle sensors 23 may be one or more. The vehicle speed sensor 24 detects the traveling speed (vehicle speed) of the forklift 1.

[0026] The drive unit 25 has, for example, a travel motor that rotates the front wheels 5, which are drive wheels, and a steering motor that steers the rear wheels 6, which are steerable wheels, although these are not shown. The alarm 26 issues an alarm by sounding or displaying an alarm when it detects the presence of an obstacle X ahead of the forklift 1 (in the direction of travel).

[0027] The controller 27 is configured with a CPU, RAM, ROM, an input / output interface, etc. The controller 27 has a pallet position calculation unit 31, a path generation unit 32, a self-position estimation unit 33, a guidance control unit 34 (first control unit), a detection area setting unit 35, a removal processing unit 36, an obstacle determination unit 37, and a deceleration / stop control unit 38 (second control unit). These functions are executed when an instruction to start automatic traveling of the forklift 1 is given, for example, by an operation switch (not shown).

[0028] The path generation unit 32, the detection area setting unit 35, the removal processing unit 36, and the obstacle determination unit 37 cooperate with the obstacle sensor 23 to form an obstacle detection device 30 that detects whether or not an obstacle X exists in the traveling direction of the forklift 1.

[0029] The pallet position calculation unit 31 calculates the position of the pallet 12 relative to the forklift 1 based on the point cloud data of the laser sensor 21. The pallet position calculation unit 31 calculates a plane equation for the front of the pallet 12 using, for example, RANSAC (Random Sample Consensus) or the least squares method, and calculates the position of the pallet 12 relative to the forklift 1 based on the plane equation.

[0030] The route generation unit 32 generates a planned travel route R (see FIG. 3) for the forklift 1 to the unloading position (described above) based on the position of the pallet 12 relative to the forklift 1 calculated by the pallet position calculation unit 31. The planned travel route R is a route along which the forklift 1 is intended to travel, and is formed by a plurality of route points P (see FIG. 6). The route generation unit 32 constitutes a route acquisition unit that acquires the planned travel route R for the forklift 1 formed by the plurality of route points P.

[0031] The self-position estimation unit 33 estimates the self-position of the forklift 1 based on the point cloud data of the laser sensor 21 and the map data stored in the map storage unit 22. Specifically, the self-position estimation unit 33 matches the point cloud data with map data using, for example, a SLAM (simultaneous localization and mapping) method to estimate the self-position of the forklift 1. SLAM is a self-position estimation technology that estimates the self-position using sensor data and map data.

[0032] The guidance control unit 34 controls the driving unit 25 so as to guide the forklift 1 to travel along the planned travel route R generated by the route generation unit 32 to the unloading position.

[0033] Fig. 4 is a flowchart showing the procedure of the guidance control process executed by the guidance control unit 34. In Fig. 4, the guidance control unit 34 first acquires data of the planned travel route R generated by the route generation unit 32 and data of the self-position of the forklift 1 estimated by the self-position estimation unit 33 (step S121).

[0034] Next, the guidance control unit 34 determines whether the amount of deviation between the current position of the forklift 1 and the planned travel route R is equal to or smaller than a threshold value (step S122). The threshold value is, for example, the width dimension W1 of the detection frame F (see FIG. 7).

[0035] When the guidance control unit 34 determines that the deviation between the current position of the forklift 1 and the planned travel route R is equal to or smaller than the threshold, the guidance control unit 34 controls the drive unit 25 to make the forklift 1 travel toward the unloading position (step S123). At this time, the guidance control unit 34 controls the drive unit 25 to make the current position of the forklift 1 approach the planned travel route R.

[0036] Next, the guidance control unit 34 determines whether the forklift 1 has reached the unloading position (step S124). If the guidance control unit 34 determines that the forklift 1 has not reached the unloading position, it executes the above-mentioned step S121 again. If the guidance control unit 34 determines that the forklift 1 has reached the unloading position, it controls the drive unit 25 to stop the forklift 1 (step S125).

[0037] When the guidance control unit 34 determines in step S122 that the deviation between the current position of the forklift 1 and the planned travel route R is greater than the threshold, the guidance control unit 34 controls the driving unit 25 to bring the forklift 1 to an emergency stop (step S126). The guidance control unit 34 controls the alarm 26 to issue an alarm (step S127).

[0038] Returning to FIG. 2, the detection area setting unit 35 sets an obstacle detection area for detecting an obstacle X that exists in the traveling direction of the forklift 1 by mapping a detection frame that entirely surrounds the forklift 1 to the route point P of the planned traveling route R generated by the route generation unit 32.

[0039] 5 is a flowchart showing the steps of the detection area setting process executed by the detection area setting unit 35. In Fig. 5, the detection area setting unit 35 first acquires data of the planned traveling route R generated by the route generating unit 32 (step S101).

[0040] 6 and 7, the detection area setting unit 35 then maps a rectangular detection frame F that entirely surrounds the forklift 1 to a plurality of route points P of the planned travel route R (step S102). At this time, the detection frame F is mapped to the route points P so that the route points P are located at the center of the detection frame F. In this way, an obstacle detection area E consisting of the plurality of detection frames F is set.

[0041] As shown in FIG. 7 , the dimensions of the detection frame F are larger in the front-to-rear and left-to-right directions of the forklift 1 than the external dimensions of the forklift 1. Specifically, the length L1 of the detection frame F is larger than the overall length L2 of the forklift 1. The overall length L2 of the forklift 1 is the length from the tips (front ends) of the forks 9 of the forklift 1 to the rear end of the vehicle body 4. The width W1 of the detection frame F is larger than the overall width W2 of the forklift 1. The overall width W2 of the forklift 1 is the vehicle width dimension of the forklift 1.

[0042] The dimensions of the detection frame F are larger in all directions by a specified amount d than the external dimensions of the forklift 1. The actual travel route of the forklift 1 may deviate from the planned travel route R due to an estimation error of the self-position generated by the self-position estimation unit 33 and a guidance error generated by the guidance control unit 34. Therefore, the specified amount d is set to a value that can absorb the deviation of the actual travel route of the forklift 1 from the planned travel route R.

[0043] The detection area setting unit 35 does not need to map detection frames F to all route points P on the planned travel route R, but may map detection frames F to route points P at predetermined intervals. This leads to a reduction in calculation processing time. In this case, by setting the intervals between route points P to be mapped so that adjacent detection frames F partially overlap, it is possible to prevent gaps in the obstacle detection area E.

[0044] In addition, the intervals between the route points P to be mapped may be shortened only in the portions where there are gaps in the obstacle detection area E, or the dimensions of the detection frame F may be increased in the portions where there are gaps in the obstacle detection area E.

[0045] After executing step S102, the detection area setting unit 35 outputs data of the obstacle detection area E to the obstacle determining unit 37 (step S103).

[0046] Returning to Fig. 2, the removal processor 36 removes reflection points corresponding to objects other than the obstacle X from the point cloud data of the obstacle sensor 23. That is, the removal processor 36 removes parts corresponding to objects other than the obstacle X from the detection data of the obstacle sensor 23. As a result, point cloud data (processed data) from which reflection points corresponding to objects other than the obstacle X have been removed is obtained.

[0047] The objects other than the obstacle X are objects whose positions and dimensions are known or obtainable. Here, the objects other than the obstacle X include the forks 9 and the pallet 12. The positions and lengths of the forks 9 and the dimensions of the pallet 12 are known in advance. The position of the pallet 12 relative to the forklift 1 is obtained by the pallet position calculation unit 31. Therefore, in the point cloud data of the obstacle sensor 23, the portions corresponding to the forks 9, the pallet 12, etc. can be easily removed.

[0048] The obstacle determination unit 37 determines whether or not an obstacle X exists in the obstacle detection area E set by the detection area setting unit 35, based on the point cloud data of the obstacle sensor 23. At this time, the obstacle determination unit 37 determines whether or not an obstacle X exists in the obstacle detection area E, based on post-processing data from which the removal processing unit 36 ​​has removed reflection points corresponding to objects other than the obstacle X.

[0049] When the obstacle determination unit 37 determines that an obstacle X exists in the obstacle detection area E, the deceleration / stop control unit 38 controls the drive unit 25 to decelerate or stop the forklift 1 and also controls the alarm 26 to issue an alarm. When the distance to the obstacle X is equal to or less than a specified value, the deceleration / stop control unit 38 controls the drive unit 25 to stop the forklift 1, and when the distance to the obstacle X is longer than the specified value, the deceleration / stop control unit 38 controls the drive unit 25 to decelerate the forklift 1.

[0050] Fig. 8 is a flowchart showing the procedure of the deceleration and stop control process executed by the deceleration and stop control unit 38. In Fig. 8, the deceleration and stop control unit 38 first determines whether or not the obstacle determination unit 37 has determined that an obstacle X exists in the obstacle detection area E (step S111).

[0051] When it is determined that the obstacle X is present in the obstacle detection area E, the deceleration / stop control unit 38 acquires the detection value of the vehicle speed sensor 24 (step S112). Then, based on the detection value of the vehicle speed sensor 24, the deceleration / stop control unit 38 calculates a distance for stopping the forklift 1 when the forklift 1 is traveling along the planned travel route R (step S113).

[0052] Here, if the current speed of the forklift 1 is v and the deceleration of the forklift 1 is a, the time t given by the following formula is required to stop the forklift 1 from traveling. Note that the deceleration a is predetermined. t=v / a

[0053] The distance x required to stop the forklift 1 is expressed by the following equation by integrating the current vehicle speed v of the forklift 1. x=v 2 / 2a

[0054] Next, the deceleration / stoppage control unit 38 determines whether or not an obstacle X is present in a stopping area e1 (see FIG. 6) within the obstacle detection region E (step S114). The stopping area e1 is an area within the obstacle detection region E that is closer to the forklift 1 than the stopping threshold value S1 (predetermined value).

[0055] The stopping threshold S1 is a value obtained by adding a margin to the distance x when the vehicle speed v of the forklift 1 is set to a fixed value v0 corresponding to an extremely slow speed. The fixed value v0 corresponding to an extremely slow speed is lower than the actual vehicle speed v of the forklift 1. The stopping threshold S1 is, for example, a position corresponding to a path point P in a detection frame F including a stopping area e1 and a deceleration area e2 (described later) (see FIG. 6).

[0056] When it is determined that an obstacle X is present in the stopping area e1 within the obstacle detection region E, the deceleration / stop control unit 38 controls the drive unit 25 to stop the forklift 1 (step S115). In addition, the deceleration / stop control unit 38 controls the alarm 26 to issue a stop warning (step S116).

[0057] When it is determined that no obstacle X is present in the stopping area e1 within the obstacle detection region E, the deceleration / stop control unit 38 determines whether or not an obstacle X is present in a deceleration area e2 (see FIG. 6) within the obstacle detection region E (step S117). The deceleration area e2 is an area within the obstacle detection region E between the stopping threshold S1 and the deceleration threshold S2.

[0058] The deceleration threshold S2 is located farther from the forklift 1 than the stop threshold S1. The deceleration threshold S2 is a value obtained by adding a margin to the distance x at the current vehicle speed v of the forklift 1. The deceleration threshold S2 is located, for example, at a position corresponding to the end of the detection frame F in the deceleration area e2 in the direction of travel that is farthest from the forklift 1 (see FIG. 6).

[0059] When the deceleration / stop control unit 38 determines that the obstacle X is present in the deceleration area e2 within the obstacle detection region E, it controls the drive unit 25 to decelerate the forklift 1 (step S118). In addition, the deceleration / stop control unit 38 controls the alarm 26 to issue a deceleration warning (step S119), and executes the above-described step S111 again.

[0060] When the deceleration / stop control unit 38 determines that no obstacle X exists in the deceleration area e2 within the obstacle detection region E, it executes the above-described step S111 again.

[0061] Incidentally, when the planned travel route R is predicted based on, for example, the current operation direction and amount of the steering wheel 15 (see FIG. 1), there is a possibility that the actual travel route of the forklift 1 will deviate significantly from the planned travel route. In manned operation, an operator operates the steering wheel, so the forklift 1 will not be stopped unless an obstacle X is present on the actual travel route. However, in unmanned operation, if the actual travel route deviates from the planned travel route, the obstacle X may be erroneously detected as being present on the actual travel route, even if it is not. In this case, the forklift 1 will stop traveling even though the obstacle X is not present on the actual travel route.

[0062] For example, as shown in Figure 9(a), when the obstacle detection area E is set based on the actual position of the forklift 1, the position of the obstacle detection area E changes depending on the actual position of the forklift 1, regardless of the planned travel route R of the forklift 1. Therefore, as shown in Figure 9(b), when the actual travel route of the forklift 1 deviates from the planned travel route R, if an obstacle X is present in the obstacle detection area E, it will be erroneously detected as being in the direction of travel of the forklift 1, even if the obstacle X is not present on the actual travel route.

[0063] To address this issue, in this embodiment, as shown in Fig. 10(a), an obstacle detection area E consisting of multiple detection frames F is set based on the planned travel route R of the forklift 1. Therefore, even if the actual travel route of the forklift 1 deviates from the planned travel route R, the position of the obstacle detection area E does not change, and if there is no obstacle X in the obstacle detection area E, it will not be erroneously detected as existing in the direction of travel of the forklift 1.

[0064] Furthermore, as shown in FIG. 10(b), when the current position of the forklift 1 deviates more than necessary from the planned travel route R, the forklift 1 makes an emergency stop regardless of whether an obstacle X is present or not.

[0065] As described above, in this embodiment, the planned travel route R of the forklift 1, which is formed by a plurality of route points P, is acquired. Then, by mapping a detection frame F that entirely surrounds the forklift 1 to the route points P of the planned travel route R, an obstacle detection area E for detecting an obstacle X that exists in the traveling direction of the forklift 1 is set. Then, based on detection data from the obstacle sensor 23 that detects the obstacle X, it is determined whether or not the obstacle X exists in the obstacle detection area E. Therefore, even if the actual travel route of the forklift 1 deviates from the planned travel route R, if the obstacle X exists in the obstacle detection area E obtained from the plurality of detection frames F, the obstacle X is detected as existing in the traveling direction of the forklift 1. This prevents erroneous detection of the obstacle X even if the planned travel route R deviates from the actual travel route. As a result, it is possible to prevent the forklift 1 from stopping due to erroneous detection of the obstacle X.

[0066] Furthermore, in this embodiment, the dimensions of the detection frame F are larger in the front-rear and left-right directions of the forklift 1 than the external dimensions of the forklift 1. In this case, the dimensions of the detection frame F have margins in the front-rear and left-right directions of the forklift 1 relative to the external dimensions of the forklift 1, so a large obstacle detection area E is set. Therefore, regardless of errors that occur when the forklift 1 travels along the planned travel route R, it is possible to accurately detect whether or not an obstacle X is present in the direction of travel of the forklift 1.

[0067] Furthermore, in this embodiment, reflection points corresponding to objects other than the obstacle X (such as the forks 9 and pallets 12) are removed from the point cloud data of the obstacle sensor 23, and based on the processed data from which the reflection points have been removed, it is determined whether or not the obstacle X is present in the obstacle detection area E. Since reflection points corresponding to objects other than the obstacle X are removed from the point cloud data of the obstacle sensor 23 in this way, erroneous detection of the obstacle X is further suppressed.

[0068] Furthermore, in this embodiment, when the distance to the obstacle X is equal to or less than the stopping threshold S1, the drive unit 25 is controlled to stop the forklift 1, and when the distance to the obstacle X is longer than the stopping threshold S1, the drive unit 25 is controlled to decelerate the forklift 1. In this way, when the presence of the obstacle X in the traveling direction of the forklift 1 is detected, the traveling state of the forklift 1 is appropriately controlled according to the distance from the forklift 1 to the obstacle X.

[0069] 11 is a block diagram showing the configuration of a travel control device according to a second embodiment of the present invention. The travel control device 20A of this embodiment is a device that controls the forklift 1 to travel automatically when loading and unloading a pallet 12.

[0070] As shown in Fig. 12(a), when loading a pallet 12, the travel control device 20A controls the forklift 1 with the pallet 12 held by the normal forks 41 to automatically travel to a loading position. The normal forks 41 are the same as the forks 9 in the first embodiment. In this case, the loading position is a position where the pallet 12 held by the normal forks 41 can be loaded on top of other pallets 12 that have already been placed.

[0071] As shown in FIG. 12(b), when unloading a pallet 12, the travel control device 20A controls the forklift 1 equipped with long forks 42 to automatically travel to the unloading position. The long forks 42 are longer than the normal forks 41. By using the long forks 42, two pallets 12 arranged in the front-to-rear direction (depth direction) can be unloaded together. The unloading position is a position where the long forks 42 can be inserted into the fork holes 13 of the two pallets 12.

[0072] The normal forks 41 and the long forks 42 are a plurality of types of detachable implements that differ in size in the front-to-rear direction of the forklift 1.

[0073] 11, the travel control device 20A includes, in addition to the configuration in the first embodiment described above, a work instruction switch 43. The work instruction switch 43 is an operation switch that allows the worker to instruct either loading work or unloading work.

[0074] Furthermore, the controller 27 of the driving control device 20A has a detection area setting unit 45 instead of the detection area setting unit 35 in the first embodiment.

[0075] The path generation unit 32, the detection area setting unit 45, the removal processing unit 36, and the obstacle determination unit 37 cooperate with the obstacle sensor 23 to form an obstacle detection device 30A that detects whether or not an obstacle X exists in the traveling direction of the forklift 1.

[0076] The detection area setting unit 45 sets an obstacle detection area E for detecting an obstacle X that exists in the traveling direction of the forklift 1 by mapping a detection frame F to a route point P of the planned travel route R. At this time, the detection area setting unit 45 maps a detection frame F with different dimensions depending on the type of fork used (see FIG. 14).

[0077] Fig. 13 is a flowchart showing the procedure of the detection area setting process executed by the detection area setting unit 45, and corresponds to Fig. 4. In Fig. 13, the detection area setting unit 45 first determines whether or not a loading operation has been instructed by the operation instruction switch 43 (step S105).

[0078] When it is determined that a loading operation has been instructed, the detection area setting unit 45 selects the detection frame Fa for the normal fork 41 as shown in Fig. 14(a) (step S106). The detection frame Fa for the normal fork 41 is the same as the detection frame F in the first embodiment described above.

[0079] If the detection area setting unit 45 determines that loading work has not been instructed, it means that unloading work has been instructed, and so selects the detection frame Fb for the long fork 42, as shown in Figure 14(b) (step S107). The length dimension L1 of the detection frame Fb for the long fork 42 is longer than the length dimension L1 of the detection frame Fa for the normal fork 41 by the difference between the lengths of the long fork 42 and the normal fork 41. The width dimension W1 of the detection frame Fb for the long fork 42 is equal to the width dimension W1 of the detection frame Fa for the normal fork 41.

[0080] After performing step S106 or step S107, the detection area setting unit 45 acquires data of the planned travel route R generated by the route generation unit 32 (step S101). Next, the detection area setting unit 45 sets an obstacle detection area E by mapping the detection frame Fa selected in step S106 or the detection frame Fb selected in step S107 to the route point P of the planned travel route R (step S102). Next, the detection area setting unit 45 outputs data of the obstacle detection area E to the obstacle determination unit 37 (step S103).

[0081] In the present embodiment as described above, as in the first embodiment, even if the planned traveling route R deviates from the actual traveling route, erroneous detection of the obstacle X is suppressed.

[0082] In addition, in this embodiment, an appropriate detection frame F is mapped to the route point P of the planned travel route R depending on the type of fork used (normal fork 41 or long fork 42). Therefore, even when multiple types of forks are used, erroneous detection of the obstacle X is suppressed.

[0083] The present invention is not limited to the above-described embodiment. In the first embodiment, the forklift 1 is controlled to travel to the unloading position when unloading the pallet 12, but the present invention is not particularly limited to such an embodiment. For example, as in the second embodiment, when loading the pallet 12, the forklift 1 may be controlled to travel to the loading position with the pallet 12 held by the forks 9. Furthermore, when performing other loading operations using the forks 9, the forklift 1 may be controlled to travel to a predetermined position.

[0084] In the second embodiment, the forklift 1 is controlled to travel to a loading position when loading the pallet 12 using the normal forks 41, and to travel to an unloading position when unloading the pallet 12 using the long forks 42. However, the present invention is not limited to this configuration. For example, loading operations may be performed using detachable forks and attachments. The forks and attachments are different types of implements that differ in size in at least the left-right direction of the forklift 1. In this case, a detection frame for the forks and a detection frame for the attachments are set.

[0085] In addition, in the above embodiment, the length dimension L1 of the detection frame F is greater than the overall length L2 of the forklift 1, and the width dimension W1 of the detection frame F is greater than the overall width W2 of the forklift 1, but this is not particularly limited to this configuration. As long as the detection frame F completely surrounds the forklift 1, only the length dimension L1 of the detection frame F may be greater than the overall length L2 of the forklift 1, or only the width dimension W1 of the detection frame F may be greater than the overall width W2 of the forklift 1. Furthermore, the length dimension L1 of the detection frame F may be equal to the overall length L2 of the forklift 1, and the width dimension W1 of the detection frame F may be equal to the overall width W2 of the forklift 1.

[0086] Furthermore, in the above embodiment, the shape of the detection frame F is rectangular, but the shape of the detection frame F is not particularly limited to a rectangle, and may be any polygon that surrounds the forklift 1 entirely.

[0087] In the above embodiment, the position of the pallet 12 relative to the forklift 1 is calculated based on the point cloud data of the laser sensor 21, and the self-position of the forklift 1 is estimated based on the point cloud data of the laser sensor 21 and the map data stored in the map storage unit 22, but the present invention is not limited to such an embodiment. For example, a laser sensor for detecting the pallet and a laser sensor for estimating the self-position may be provided separately.

[0088] In the above embodiment, the self-position of the forklift 1 is estimated using the SLAM method using point cloud data from the laser sensor 21, but the present invention is not limited to such a method. Methods for estimating the self-position of the forklift 1 may also use, for example, the SLAM method using image data from a camera, an odometry sensor that detects the amount and direction of movement of the forklift 1, or an inertial measurement unit (IMU) that measures the angular velocity and acceleration of the forklift 1.

[0089] Furthermore, in the above embodiment, the planned travel route R of the forklift 1 is generated based on the position of the pallet 12 relative to the forklift 1, but this is not limited to a particular configuration. For example, if the position of the pallet 12 relative to the forklift 1 is not calculated, the planned travel route R of the forklift 1 may be predicted based on the direction and amount of operation of the handle 15 of the forklift 1, etc.

[0090] Furthermore, in the above embodiment, the forklift 1 is controlled to travel along the planned travel route R to a predetermined position, but the present invention is also applicable to industrial vehicles such as towing tractors. [Explanation of symbols]

[0091] 1...forklift (industrial vehicle), 9...fork (work implement), 20, 20A...travel control device, 23...obstacle sensor (obstacle detection unit), 25...drive unit, 30, 30A...obstacle detection device, 32...route generation unit (route acquisition unit), 34...guidance control unit (first control unit), 35...detection area setting unit, 36...removal processing unit, 37...obstacle determination unit, 38...deceleration and stop control unit (second control unit), 41...normal fork (work implement), 42...long fork (work implement), 45...detection area setting unit, P...route point, R...planned travel route, E...obstacle detection area, F...detection frame, Fa, Fb...detection frame, L1...length dimension, W1...width dimension, L2...total length (front-to-back dimension), W2...total width (left-to-right dimension), S1...stop threshold (default value), X...obstacle.

Claims

1. An obstacle detection device mounted on a forklift having elevating forks that hold a pallet, a route acquisition unit that acquires a planned travel route of the forklift formed by a plurality of route points; a detection area setting unit that sets an obstacle detection area for detecting obstacles present in a traveling direction of the forklift by mapping a detection frame that entirely surrounds the forklift to the route points of the planned travel route acquired by the route acquisition unit; an obstacle detection unit that detects the obstacle; an obstacle determination unit that determines whether or not an obstacle exists in the obstacle detection area set by the detection area setting unit based on detection data from the obstacle detection unit; a removal processing unit that removes a portion corresponding to an object other than the obstacle from the detection data of the obstacle detection unit, the route acquisition unit calculates a position of the pallet relative to the forklift, and generates the planned travel route of the forklift based on the position of the pallet; the object other than the obstacle is the fork and the pallet, the positions and dimensions of which are known or obtainable; the removal processing unit acquires the position of the pallet relative to the forklift calculated by the path acquisition unit, and removes portions of the detection data of the obstacle detection unit that correspond to the forks and the pallet based on the position of the pallet, the known positions of the forks, the lengths of the forks, and the dimensions of the pallet; The obstacle determination unit determines whether the obstacle is present in the obstacle detection area based on processed data from which the portions corresponding to the forks and the pallet have been removed by the removal processing unit.

2. 2. The obstacle detection device according to claim 1, wherein the dimensions of the detection frame are larger than the outer dimensions of the forklift in the front-rear and left-right directions of the forklift.

3. The forklift has a plurality of types of detachable forks that differ in dimension in at least one of the front-rear direction and the left-right direction of the forklift, The obstacle detection device according to claim 1 , wherein the detection area setting unit maps the detection frame having different dimensions depending on the type of the fork.

4. A travel control device mounted on a forklift having elevating forks that hold a pallet, a drive unit that drives the forklift; a route acquisition unit that acquires a planned travel route of the forklift formed by a plurality of route points; a first control unit that controls the drive unit so as to cause the forklift to travel along the planned travel route; a detection area setting unit that sets an obstacle detection area for detecting obstacles present in a traveling direction of the forklift by mapping a detection frame that entirely surrounds the forklift to the route points of the planned travel route acquired by the route acquisition unit; an obstacle detection unit that detects the obstacle; an obstacle determination unit that determines whether or not an obstacle exists in the obstacle detection area set by the detection area setting unit based on detection data from the obstacle detection unit; a second control unit that controls the drive unit to decelerate or stop the forklift when the obstacle determination unit determines that the obstacle exists in the obstacle detection area; a removal processing unit that removes a portion corresponding to an object other than the obstacle from the detection data of the obstacle detection unit, the route acquisition unit calculates a position of the pallet relative to the forklift, and generates the planned travel route of the forklift based on the position of the pallet; the object other than the obstacle is the fork and the pallet, the positions and dimensions of which are known or obtainable; the removal processing unit acquires the position of the pallet relative to the forklift calculated by the path acquisition unit, and removes portions of the detection data of the obstacle detection unit that correspond to the forks and the pallet based on the position of the pallet, the known positions of the forks, the lengths of the forks, and the dimensions of the pallet; The obstacle determination unit determines whether the obstacle is present in the obstacle detection area based on processed data from which the portions corresponding to the forks and the pallet have been removed by the removal processing unit.

5. 5. The travel control device according to claim 4, wherein the second control unit controls the drive unit to stop the forklift when the distance to the obstacle is equal to or shorter than a specified value, and controls the drive unit to decelerate the forklift when the distance to the obstacle is longer than the specified value.

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