JP3113457B2 - Work vehicle travel control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pair of left and right traveling devices, traveling speed detecting means for detecting respective traveling speeds of a pair of left and right traveling devices, and speed changing operations of the traveling speeds of the pair of left and right traveling devices. A shift operation unit; and a control unit that controls operation of the shift operation unit based on detection information of the traveling speed detection unit such that each traveling speed of the pair of left and right traveling devices reaches a set target speed. The present invention relates to a traveling control device for a working vehicle.

[0002]

2. Description of the Related Art A traveling control device for a working vehicle of this type is used for an unmanned working vehicle such as a mowing robot to travel in a working area of a predetermined shape and perform mowing work in the working area. However, conventionally, when the vehicle travels straight, for example, along a predetermined route set in the work area, the traveling speeds of the left and right traveling devices are set to be equal, that is, the same target speed, and the left and right traveling devices are set. The shift operation means is actuated so that each of the traveling speeds reaches the set target speed, and traveling is started. The traveling speeds of the left and right traveling devices are individually changed and controlled from the above-mentioned set speeds so as to reduce the vehicle speed.

[0003]

However, in a case where the working area is a slope such as a river embankment and the vehicle travels in a state where the vehicle body is inclined left and right, the left and right traveling devices have a slope. The traveling device located on the lower side slips more easily than the traveling device located on the upper side of the slope, that is, the conversion rate from the traveling speed to the actual ground speed is smaller. Therefore, when the vehicle travels with the traveling speeds of the left and right traveling devices set to be equal to each other as in the above-described related art, the vehicle body travels toward the lower side of the slope and is largely displaced from the path to the lower side of the slope. , It takes a relatively long time to change the traveling speed to return to the set route,
You will not be able to travel along the regular path in the work area. As a result, uncut leaves may occur, or
There is a problem that wasteful work such as re-cutting the already cut place is caused.

The present invention has been made in view of the above circumstances, and has as its object to drive a vehicle body along a set route while maintaining a difference in ground speed between a pair of left and right traveling devices at a set speed difference. Therefore, correction information for correcting the target speed of the left and right traveling devices is obtained from the change speed of the body azimuth angle caused by the ground speed difference between the left and right traveling devices, and each of the left and right traveling devices is determined based on the correction information. It is an object of the present invention to set the traveling speed appropriately in accordance with the situation of a work place or the like, and to solve the above-mentioned disadvantages of the related art.

[0005]

According to a first feature of the traveling control device for a working vehicle according to the present invention, an angular velocity detecting means for detecting a change speed of a vehicle body azimuth angle is provided, and the control means comprises the angular velocity detecting means. Correction information for correcting the target speed in order to make the difference between the ground speeds of the pair of left and right traveling devices a set speed difference based on the detection information of the means and the information on the lateral spacing of the pair of left and right traveling devices in the vehicle body. The speed change operating means is operated based on the detection information of the traveling speed detecting means so that the traveling speeds of the pair of left and right traveling devices are the corrected speeds obtained by correcting the target speed with the correction information. The point is that it is configured to control.

In a second characteristic configuration, there is provided a vehicle body position detecting means for detecting a lateral displacement and an inclination of the vehicle body with respect to a set traveling route, and the control means includes a detecting means for detecting the vehicle body position detecting means. The operation of the shift operation means is controlled based on the information, and the process for obtaining the correction information is performed in a state where the vehicle body is guided and guided along the set traveling route.

[0007]

According to the first characteristic configuration of the present invention, the change speed of the azimuth angle of the vehicle body is detected, and the pair of left and right traveling devices is determined based on the detected information and the information on the lateral spacing of the pair of left and right traveling devices in the vehicle body. Correction information for correcting the target speed of each of the left and right traveling devices is determined in order to make the difference between the ground speeds of the vehicle and the set speed difference, and the traveling speeds of the pair of left and right traveling devices detected by the traveling speed detecting means are determined. However, the operation of the shift operation means is controlled such that the target speed is corrected based on the correction information, and the respective traveling speeds of the pair of left and right traveling devices are individually shifted.

According to the second characteristic configuration, the shift operation means is controlled based on the detection information of the lateral displacement and the inclination of the vehicle body with respect to the set travel path, and the vehicle body is moved to the set travel path. In the state where the vehicle is guided along the road, a process of obtaining the correction information is performed.

[0009]

Therefore, according to the first characteristic configuration of the present invention, the target speed is corrected such that the difference between the ground speeds of the pair of left and right traveling devices becomes the set speed difference, and each of the left and right traveling devices is corrected. Since the traveling speed is shifted, for example, in a case where the vehicle travels straight in a state where the vehicle body is inclined left and right, as in the related art in which the vehicle travels with the traveling speeds of the left and right traveling devices set to be equal, It is possible to travel along the regular path in the work area without a large displacement from the predetermined traveling route set in the work area to the lower side of the slope, and as a result, for example, In the case of the work vehicle of the first embodiment, a work control device for a work vehicle having excellent running reliability is obtained without generating uncut or causing unnecessary work such as re-cutting the already cut area. Reached.

Further, according to the second characteristic configuration, in order to guide the vehicle along the set traveling route, the correction is performed in a state where the difference between the ground speeds of the left and right traveling devices is maintained at the set speed difference. Since the information is obtained, the correction information becomes appropriate correction information corresponding to the traveling condition when the vehicle is guided along the set traveling route. By performing the shift operation of the traveling device, the vehicle body can be guided and guided in a state along the set traveling route appropriately, and the effect of the first characteristic configuration can be further enhanced.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 2, a work vehicle 1 as an unmanned mowing robot reciprocates along a linear work process 2 set in parallel at predetermined intervals in a work area AR. The work vehicle 1 includes a crawler traveling device 3 as a pair of left and right traveling devices.
And a mowing device 4. The mowing operation is performed while moving forward along the work process 2, and the turning operation is performed at the end of the work process 2 to move to the adjacent work process 2. The width of the left and right crawler traveling devices 3 in the lateral direction of the vehicle is set to W, which is the distance between the centers of the widths of the right and left crawlers (see FIG. 4).

A beam light projecting means for projecting a laser beam serving as a guiding beam light when the work vehicle 1 automatically travels as described above is provided on the ground side. That is, work process 2
A plurality of laser projectors 5 for projecting a laser beam B1 from one end side to the other end side of the work vehicle are arranged outside the work area AR along one side thereof, and the end of each work process 2 is set to a work vehicle. A laser projector 6 for projecting a laser beam B2 for notifying the user 1 is installed at both ends of the work process 2.

As shown in FIGS. 3 and 4, laser beams B1 and B2 projected from the laser projectors 5 and 6 are scanned vertically within a range of predetermined angles θ1 and θ2. This means that even if the work area AR is on uneven ground and the work vehicle 1 moves up and down during traveling, the light receiving sensors 8 and 9 on the work vehicle 1 side can reliably receive the laser beams B1 and B2. This is to make it possible. The laser projectors 5 and 6 include a semiconductor laser device 13 as a laser light source, a movable mirror 14 for reflecting a laser beam emitted upward from the semiconductor laser device 13 in a direction substantially parallel to the ground, and a movable mirror 14. A galvano scanner 15 that swings in a predetermined angle range is provided.

A pair of front and rear light receiving sensors 8 for receiving a laser beam B1 projected along the work process 2 are provided above the work vehicle 1, and based on information received by the light receiving sensor 8, the work vehicle 1 Information for traveling straight along B1 is obtained. Further, on the left and right side surfaces of the work vehicle 1, there are provided light receiving sensors 9 for receiving a laser beam B2 indicating the end of the work process 2.
Has reached the end of the work process 2.

As shown in FIGS. 2 and 3, a support frame 8a for supporting a pair of front and rear light-receiving sensors 8 is pivotally attached to the vehicle body at a central portion thereof so as to be rotatable around a vertical axis P. The direction of the support frame 8a with respect to the vehicle body differs by 180 degrees depending on whether the traveling direction of the work vehicle 1 approaches or away from the laser projector 5. That is, as the work vehicle 1 turns at the end of the work process 2 and moves to an adjacent process, the support frame 8a rotates 180 degrees around the longitudinal axis P, and the light receiving surface of the light receiving sensor 8 always emits laser light. It faces the machine 5.

Each of the light receiving sensors 8 has a shape elongated in the vehicle width direction, and is constituted by arranging a plurality of (for example, 16) light receiving elements along the longitudinal direction, and receives the laser beam B1 from the laser projector 5 in the light receiving sensor. In the case of 8, at least one of the light receiving elements is in a state of detecting light. Therefore, it is possible to detect the light receiving position in the longitudinal direction (vehicle width direction), that is, the displacement of the work vehicle 1 in the vehicle width direction with respect to the laser beam B1 depending on the number of the light receiving elements from the end that has received the light. it can. Also, the inclination (azimuth shift) of the vehicle body with respect to the laser beam B1 can be detected from the difference between the light receiving positions of the pair of front and rear light receiving sensors 8. That is, as shown in FIG. 5, the light receiving positions (distance from the end) of the front and rear light receiving sensors 8 are X1, X2 respectively.
X2, and the distance from the end of the light receiving sensor 8 to the center is X
0, assuming that the distance in the front-rear direction of the front and rear light-receiving sensors 8 is d, ΔX = X1-X0 is a displacement in the vehicle width direction,
φ = tan −1 [(X2−X1) / d] is the misalignment of the vehicle body. Therefore, if the positional deviation ΔX is a positive value, the work vehicle 1 is shifted to the left from the reference position (the projection position of the laser beam B1), and if the azimuth deviation φ is a positive value, the work vehicle 1 is Is tilted to the left of the reference direction (the projection direction of the laser beam B1). As described above, the pair of front and rear light-receiving sensors 8 constitute a vehicle body position detecting means for detecting the positional deviation ΔX and the inclination φ of the vehicle body in the vehicle lateral direction with respect to the work process 2 as the set traveling route.

As shown in FIG. 1, a controller 10 using a microcomputer is provided in the work vehicle 1, and light receiving information of the light receiving sensors 8, 9 is input to the controller 10. In addition, a laser gyro 18 as an angular velocity detecting means for detecting a change speed of the azimuth of the vehicle body is mounted on the work vehicle 1, and a left and right as a traveling speed detecting means for detecting each traveling speed of the pair of right and left crawler traveling devices 3 is provided. A pair of rotation speed sensors 19 are provided on each of the left and right crawler driving rotation shafts, and detection information from the laser gyro 18 and the left and right rotation speed sensors 19 is also input to the controller 10.

A transmitter 21 for transmitting command information for manual operation to the work vehicle 1 is provided, and a receiver 2 mounted on the work vehicle 1 so as to receive the transmission information from the transmitter 21.
Information from 0 is input to the controller 10. The transmitter 21 includes an automatic manual changeover switch 21a for switching the control between automatic control and manual control, and a shift switch for selectively switching the vehicle speed of the work vehicle 1 between two steps of high speed and low speed and a stop state in manual control. 21b, and a volume-type steering operation switch 21c for changing the steering direction to the left or right. When the steering operation switch 21c is not operated, the steering operation switch 21c is biased to return in the straight traveling direction.

The traveling speeds of the left and right crawler traveling devices 3 are as follows:
The gears can be individually shifted by a hydraulic continuously variable transmission 11, and the controller 10 adjusts the angle of the variable swash plate in the hydraulic pump of the left and right continuously variable transmissions 11 by means of a speed change motor 12. The traveling speeds of the left and right crawler traveling devices 3 are separately set by separately changing the traveling speed. Accordingly, the left and right speed change motors 12 constitute shift operation means for shifting the traveling speeds of the pair of left and right crawler traveling devices 3 separately, and the controller 10 detects detection information of the left and right rotation speed sensors 16. And control means for controlling the operation of the left and right speed change motors 12 so that the respective traveling speeds of the pair of left and right crawler traveling devices 3 become the set target speeds.

The control means, that is, the controller 1
0 is the detection information of the laser gyro 18 (that is, the change speed of the azimuth of the vehicle body) and the pair of left and right crawler traveling devices 3.
To correct the target speed so that the difference between the ground speeds of the pair of left and right crawlers 3 becomes the set speed difference, based on the information on the lateral width of the vehicle body (that is, the distance W between the centers of the horizontal widths of the left and right crawlers) The correction information (correction coefficients KL and KR described later) is obtained, and the traveling speeds of the pair of left and right crawler traveling devices 3 are calculated as follows.
The operation of the left and right shift motors 12 is controlled so that the corrected speed is corrected by the correction information. This will be specifically described below.

As shown in FIG. 6, when the traveling speeds of the left and right crawler traveling devices 3 are set to VL and VR, respectively, the traveling speed of each of the left and right crawler traveling devices 3 is changed from the traveling speed to the ground speed. If the conversion rates are KL and KR, respectively, the ground speeds of the left and right crawler traveling devices 3 are KL × VL and KR, respectively.
× VR. And if the two ground speeds are the same, the vehicle body azimuth does not change and the vehicle goes straight, but if there is a difference in both ground speeds, the vehicle azimuth changes so that the vehicle leans to the side with the lower ground speed, The change speed ω of the body azimuth at that time is obtained by the following equation (1). It should be noted that the direction in which the vehicle body turns clockwise when viewed from above is set to a positive value.

[0022]

Ω = (KL × VL−KR × VR) / W (1)

In the above equation, the change speed ω of the body azimuth angle
The traveling speeds VL and VR of the left and right crawler traveling devices 3 are obtained as detection values.
Is determined as a constant. Accordingly, the conversion rates KL, KR from the traveling speed of the crawler traveling device 3 to the ground speed are treated as correction coefficients for control, and provisional values are set, and both values calculated from the provisional conversion rates KL, KR are calculated. An error E between the calculated value of the difference in ground speed (KL × VL−KR × VR) and the measured value (ω × W) is obtained as in the following equation (2), and the error E between the calculated value and the measured value is obtained. The values of the conversion rates KL and KR are successively corrected so that the values of the conversion rates KL and KR become small.
It is obtained as correction coefficients KL and KR as the correction information.

[0024]

E = (KL × VL−KR × VR) − (ω × W) (2)

[0025] In fact, as the square of the value E ^2/2 of the error E is small, the conversion ratio KL before correction, conversion KL revised from KR ', KR' the following expression (3) Correct sequentially.
Note that k in the equation is a positive coefficient of a predetermined size. From this equation, for example, when the error E is positive, that is, when the calculated value of the difference between the ground speeds (KL × VL−KR × VR) is larger than the actually measured value (ω × W), the left crawler traveling The value of the conversion rate KL from the traveling speed of the device 3 to the ground speed is corrected in the direction of decreasing, while the value of the conversion ratio KR of the right crawler traveling device 3 from the traveling speed to the ground speed is corrected in the direction of increasing. Therefore, the calculated value of the difference (KL × VL−KR × VR) between the ground speeds is corrected to be small, and the error E approaches zero.

[0026]

[Number 3] KL '= KL -k × d ( E 2/2) / dKL = KL -k × E × VL KR' = KR -k × d (E 2/2) / dKR = KR + k × E × VR ............ (3)

The controller 10 stops one of the left and right crawler traveling devices 3 based on a signal indicating that the light receiving sensor 9 on the left or right side of the work vehicle 1 has received the laser beam B2. Then, turn 180 degrees to the left or right to move to the next work step 2. At this time, as described above, the support frame 8a of the light receiving sensor 8 is moved 180 degrees around the vertical axis P.
Rotate degrees. As the light receiving sensor 8 receives the laser beam B1 in the next work step 2, the automatic traveling along the laser beam B1 is started.

Each time the light receiving sensor 9 receives the laser beam B2, that is, every time the end of the work process 2 is detected, the controller 10 increments the value of the previously stored work process number by one. Subtract. When the value of the number of work steps becomes zero, the work is completed. Note that the initial value of the number of work steps is manually set by the dial-type work step number setting means 17 before the start of the work, for example.

Next, based on the flow chart shown in FIG. 7, taking the case where the work vehicle 1 travels straight ahead as an example, the conversion rates KL and KR as the correction coefficients of the controller 10 will be described.
The estimation processing and automatic traveling control will be described.

First, when the control is started, a target value of the vehicle speed V is set, and tentative values are set for the conversion rates KL and KR from the running speed to the ground speed. This conversion rate KL, K
As the value of R, for example, when traveling on a slope inclined to the right as shown in FIG. 4, the right crawler traveling device 3 is easier to slip than the left crawler traveling device.
= 0.9, KR = 0.8. Further, the azimuth deviation φ of the vehicle body from the reference azimuth (the projection direction of the laser beam B1) and the positional deviation ΔX from the reference position (the projection position of the laser beam B1) in the vehicle width direction are detected. Then, based on these, the traveling speeds VL, VR of the left and right crawler traveling devices 3 are set as in the following formula, and the work vehicle 1 is caused to travel at the set traveling speeds VL, VR. Note that α, β in the equation
Is a positive gain coefficient.

[0031]

VL = V + α × φ + β × ΔX VR = V−α × φ−β × ΔX (4)

Next, the change speed ω of the vehicle body azimuth is detected,
The measured value (ω × W) of the difference between the ground speeds of the left and right crawler traveling devices 3 obtained from the detected value and the calculated value (K
An error E (Equation (2)) from L × VL−KR × VR is calculated. If the error E is not sufficiently small, the values of the conversion rates KL and KR are corrected in accordance with the equation (3), and then the azimuth shift φ and the position shift ΔX of the vehicle body are continued until the error E becomes sufficiently small. The flow from the detection of is repeated.
If the error E becomes sufficiently small, the conversion rate K at that time is obtained.
Based on the values of L and KR, the traveling speeds VL and VR of the left and right crawler traveling devices 3 for causing the working vehicle 1 to travel straight are set as in the following equation (5), and the set traveling speed VL ,
Run until the work is completed at VR. In addition, as shown in FIG. 4, when reciprocating on a slope inclined left and right,
The values of the conversion rates KL and KR determined above are used interchangeably for going and returning.

[0033]

## EQU5 ## VL = V / KL, VR = V / KR (5)

From the above, the control means (controller 1)
0) controls the operation of the speed change motor 12 based on the detection information of the pair of light receiving sensors 8 to guide the vehicle body along the work process 2 while the correction coefficients KL and KR are set. Is performed.

Although not shown, when the work vehicle 1 is largely deviated from the straight traveling state while traveling at the traveling speeds VL and VR set by the above equation (5), an interruption process is performed. After the worker or the like manually controls the work vehicle 1 by the transmitter 21 to return to the straight traveling state, the control is returned to the automatic control. Then, with the return to the automatic driving, the processing of the automatic traveling control described above is executed.

[Another Embodiment] In the above embodiment, the difference between the ground speed of the pair of left and right traveling devices is actually measured from the information on the change speed of the azimuth angle of the vehicle body and the information on the distance between the pair of left and right traveling devices in the lateral direction of the vehicle. On the basis of the information on the difference in ground speed between the pair of left and right traveling devices and the information on each traveling speed of the pair of left and right traveling devices, a pair of left and right traveling devices is used to set the difference in ground speed between the left and right traveling devices to a set speed difference. As the correction information for correcting the target speed of the traveling device, the conversion rates KL and KR from the traveling speed of each of the left and right traveling devices to the ground speed are used.
Has been shown to determine the correction coefficients KL and KR related to the above, but the specific configuration for obtaining the correction information is not limited to this.

In the above embodiment, the two correction coefficients KL
, KR are obtained by successively correcting or the like. Alternatively, for example, one correction coefficient may be set to a predetermined value, and only the other correction coefficient may be obtained by successive correction or the like. .

In the above embodiment, the pair of left and right traveling devices 3 is controlled based on the information of the correction coefficients KL and KR so that both ground speeds of the traveling devices 3 become equal, that is, the work vehicle 1 travels straight. Although the case where each traveling speed of the traveling device 3 is set has been exemplified, the case where the work vehicle 1 travels along a predetermined curved path by making the ground speeds of the pair of left and right traveling devices 3 different from each other. Also applicable to

Further, in the above embodiment, the pair of left and right traveling devices 3 is constituted by a crawler traveling device, but may be constituted by a wheel type.

In the above embodiment, both the traveling speeds of the pair of left and right traveling devices 3 are controlled separately. However, for example, the traveling speed of one traveling device 3 is fixed to the reference speed. Alternatively, the relative ratio of the traveling speed of the other traveling device 3 to the reference speed may be changed and controlled.

In the above embodiment, the means 19 for detecting the traveling speed of the pair of left and right traveling devices 3 is constituted by the pair of rotation speed sensors 19 provided on the respective rotating shafts for driving the left and right crawlers. In addition, a rotation speed sensor 19 provided on the idler shaft that guides the crawler, or a photoelectric sensor that directly detects the moving speed of the crawler itself may be used.

In the above embodiment, the angular velocity detecting means 18 for detecting the change speed of the azimuth of the vehicle body is constituted by a laser gyro, but the invention is not limited to this.

In the above embodiment, the present invention is applied to the working vehicle 1 which is an unmanned mowing robot.
The present invention can be applied to various other working vehicles.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the attached drawings by the entry.

[Brief description of the drawings]

FIG. 1 is a block diagram of a control configuration.

FIG. 2 is a plan view of a work vehicle, its guidance device, and a work area.

FIG. 3 is a side view of the working vehicle.

FIG. 4 is a rear view of the working vehicle.

FIG. 5 is an explanatory diagram of detection of a position shift and a direction shift of a work vehicle.

FIG. 6 is an explanatory diagram of calculation of a conversion rate from a traveling speed to a ground speed.

FIG. 7 is a flowchart of a control operation.

[Explanation of symbols]

 Reference Signs List 3 traveling device 8 vehicle body position detecting means 10 control means 12 shift operation means 18 angular velocity detecting means 19 traveling speed detecting means

──────────────────────────────────────────────────続 き Continuation of the front page (72) Ryozo Kuroiwa 64, Ishizukita-cho, Sakai-shi, Osaka Kubota Sakai Works Co., Ltd. (56) References JP-A-63-192306 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) A01B 69/00 303 G05D 1/00-1/02 G05D 13/62

Claims (2)

(57) [Claims] A traveling speed for detecting each traveling speed of a pair of left and right traveling devices (3) and a pair of left and right traveling devices (3).
Detecting means (19) and a pair of left and right traveling devices (3)
Shift operation means (12) for shifting the running speed separately
And the detection information of the traveling speed detecting means (19),
Each traveling speed of the pair of left and right traveling devices (3) is set.
The speed change operation means (12)
And a control means (10) for controlling operation of the work vehicle, wherein the control means (10) is provided with an angular velocity detection means (1) for detecting a change speed of a vehicle body azimuth angle.
8) is provided, said control means (10), said angular velocity detecting means (18)
Vehicle body than the lateral spacing information, the pair of left and right traveling devices of the detection information, and the pair of left and right traveling devices (3) (3)
The target speed to make the ground speed difference
Find the correction information for correcting the
The respective traveling speeds of the device (3) are determined by the correction information based on the target value.
The traveling speed detection is performed so that the corrected speed becomes the corrected speed.
The speed change operation means based on the detection information of the output means (19).
(12) A travel control device for a work vehicle configured to control the operation of (12) . 2. A position in a vehicle lateral direction with respect to a set traveling route.
Vehicle position detecting means for detecting displacement and vehicle body inclination
(8) is provided, and the control means (10) is provided with the vehicle body position detecting means (8).
Operating the shift operation means (12) based on the detection information of
Control to guide the vehicle along the set travel route.
In a state where the correction information is obtained.
Cormorants work vehicle travel control device according to claim 1, wherein being configured to.