JPH0678604A - Apparatus for guiding working vehicle - Google Patents

Abstract

PURPOSE:To provide a working vehicle guiding apparatus having simple structure and enabling the driving of a working vehicle along a prescribed working route at a prescribed speed. CONSTITUTION:A guiding vehicle 6 is moved at a prescribed speed along a guide rail 5 set up on the ground. A working vehicle 1 is provided with a longitudinal deviation detection means 12 to detect the deviation of the position in the moving direction relative to the guiding vehicle 6, a distance-detection means and a motion controlling means to drive the working vehicle 1 in such a manner as to eliminate the discrepancy of the position detected by the longitudinal deviation detection means 12. A light beam source 11 is mounted on the guiding vehicle 6 and the working vehicle 1 is provided with a pair of longitudinal deviation detection means 12. The distance between the working vehicle 1 and the guiding vehicle 6 is calculated based on the time from the reception of the light beam by one of a pair of the deviation detection means to the reception of the beam by the other detection means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work vehicle guiding apparatus for automatically running a work vehicle along a predetermined work stroke.

[0002]

2. Description of the Related Art As one of the guidance devices for such work vehicles,
For example, there is a configuration in which a light beam is projected from the ground side along a work route and a work vehicle is automatically driven while following the light beam by a light receiving sensor. It is an effective guiding device when a physical guiding line cannot be laid along the work route.

Conventionally, even in the case of using the above guiding device, the traveling speed of the work vehicle is detected from the number of rotations of the drive wheels per unit time, as in the case of self-sustained traveling. It was Therefore, in order to travel at a constant speed, the rotation speed of the driving wheels and the like are kept constant.

[0004]

However, in the above method, when slip is likely to occur due to the condition of the road surface on which the vehicle is traveling, the traveling speed is not constant even if the rotational speed of the drive wheels is constant. On the other hand, it is often necessary to run at a constant speed in order to maintain a constant work performance while the work vehicle is running. For example, in the case of a work vehicle for mowing work, constant speed traveling is desirable in order to match the rotation speed of the rotary blade of the mowing device to the traveling speed.

The present invention has been made in view of the above circumstances, and an object thereof is to guide a work vehicle with a simple structure so that the work vehicle can travel at a set speed along a predetermined work stroke. To provide a device.

[0006]

A first characteristic structure of a guide device for a work vehicle according to the present invention is provided with a guide vehicle which travels at a set speed along a guide rail installed on the ground side. A front and rear displacement detecting means for detecting a positional deviation in the traveling direction with respect to the guided vehicle, a distance detecting means for detecting a distance to the guided vehicle in the vehicle width direction, and a distance set by the distance detecting means for setting a target. And a traveling control means for traveling the work vehicle so that the positional deviation detected by the longitudinal displacement detecting means becomes zero while maintaining the value.

The second characteristic structure is to specify a preferable specific structure for carrying out the first characteristic structure, and scanning means for scanning the guide vehicle with the light beam in a vertical direction at a predetermined angular velocity. And a pair of front-rear displacement detection means configured by arranging a plurality of light-receiving elements that receive the light beam in the traveling direction are provided in the work vehicle at a predetermined interval in the up-down direction. The distance detecting means determines the distance between the work vehicle and the guided vehicle based on the time from when one of the pair of front and rear displacement detecting means receives the light beam until the other receives the light beam. It is configured to calculate.

[0008]

According to the first characteristic configuration, the guide rail is installed outside the work area along one side of the rectangular work area, for example, and the guided vehicle is run at the set speed along the guide rail. The traveling control means of the work vehicle, based on the detection information of the distance detection means and the detection information of the longitudinal displacement detection means,
While keeping the distance between the work vehicle and the guide vehicle in the vehicle width direction at the set target value, the work vehicle should follow the guide vehicle side by side so that the positional deviation from the guide vehicle in the traveling direction becomes zero. Let it run. That is, the vehicle travels at the same set speed as the guided vehicle while increasing / decreasing the driving force so as to compensate for the slip with the traveling road surface, and the steering control is performed so as to draw a trajectory substantially parallel to the guide rail.

When the work area is composed of a plurality of work steps parallel to the guide rails, in order to drive the work vehicle over the entire work path, for example, an induction vehicle is reciprocated a predetermined number of times along the guide rails. Let it run. Then, the traveling control means of the work vehicle increases (or decreases) the set target value by a predetermined distance (distance between adjacent strokes) in accordance with the detection of the stop at the end of the traveling range of the guided vehicle, and After moving to the next work stroke, the control for following and steering the work vehicle in parallel with the guided vehicle may be repeated a predetermined number of times ((the number of work strokes-1) times).

According to the second characteristic configuration, the guide vehicle in the traveling direction of the work vehicle from the position where the beam light projected from the beam light source mounted on the guide vehicle hits the longitudinal displacement detection means mounted on the work vehicle. The positional deviation of is detected. That is, the front-rear displacement detecting means is composed of a plurality of light receiving elements arranged in the traveling direction, and the state where the light beam impinges on the central light receiving element is the state in which the displacement is zero.

Further, the beam light projected from the beam light source is scanned by the scanning means in the vertical direction at a predetermined angular velocity, and a pair of front-back displacement detection means is provided in the vertical direction at a predetermined interval. Therefore, the time from when one of the pair of front-back displacement detecting means receives the light beam to when the other receives the light beam is τ, and the angular velocity is ω,
If the above-mentioned predetermined interval is d, the distance r from the beam light source to the front-back displacement detecting means is r≈d / (ωτ). d,
Since ω is a constant, the distance detecting means calculates the distance from the beam light source to the front-rear displacement detecting means based on τ, in other words, the distance r between the guide vehicle and the work vehicle.

Scanning the light beam in the vertical direction is also necessary so that the front-rear displacement detecting means can always receive the light beam even if the road surface of the work vehicle has irregularities. Further, by providing a pair of front-back displacement detection means not only in the vertical direction but also in the vehicle width direction by a predetermined distance,
It is also possible to detect the inclination (direction) of the vehicle body with respect to the traveling direction.

[0013]

As described above, according to the present invention, it is possible to provide a guide device for a work vehicle capable of traveling at a set speed along a predetermined work stroke with a simple structure.
Moreover, according to the second characteristic configuration, the above effect can be obtained by using the means necessary for the general guidance by the light beam.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, an unmanned work vehicle 1 for mowing works travels along a predetermined work path 2 in a work area AR. The work vehicle 1 includes a crawler traveling device 3 and a mowing device 4.
And mowing work is performed while moving forward or backward along a work path 2 set in the long side direction of the work area AR divided in a rectangular shape in a plan view, and in the short side direction at the end of the work step 2. The work is moved to the adjacent work stroke 2 by moving the width by a predetermined distance. Further, as shown in FIG. 2, the work area AR
Is installed on the slope of the embankment.

A guide rail 5 is installed outside the work area AR, that is, at the end of the plane portion of the embankment along the long side direction of the work area AR, and travels back and forth on the guide rail 5 to drive the work vehicle 1. An induction vehicle 6 that guides traveling is provided. As shown in the plan view of FIG.
Pair of idler wheels 7 that roll with the sides of the
Prepare for front and back. Further, a drive wheel 8 and an idle wheel 9 which roll on the upper surface of the guide rail 5 are provided.

The drive wheel 8 is driven forward or backward at a set rotational speed by a servo motor (not shown), so that the guide wheel 6 moves forward or backward on the guide rail 5 at the set speed. In addition, the end of the reciprocating traveling range, that is, the end of the work stroke is determined by integrating the amount of forward and backward movement based on the detection signal of the rotation speed sensor 10 that detects the rotation speed of the drive wheel 8. A controller (not shown) is provided for controlling the forward / reverse rotation and the stop of the. However, the guide rail 5 is provided with a mark indicating the end of the reciprocating traveling range, and when the mark sensor (not shown) provided in the guided vehicle 6 detects the mark, the controller reciprocates based on this mark. The end of the traveling range is determined, and the integrated value of the movement amount is initialized. The integrated value of the movement amount is also used for determining the inter-stroke distance (moving pitch) in the vertical cutting guidance described later.

A laser projector 11a is provided on the upper portion of the guided vehicle 6,
A beam light source 11 including a rotating mirror 11b and a drive motor 11c thereof is mounted. A laser beam (hereinafter referred to as a beam light) projected upward from the laser projector 11a is reflected by the rotating mirror 11b, and is reflected in a direction shown by a broken line in FIGS. 1 to 3, that is, a direction perpendicular to the guide rail 5. It is projected.

However, the rotary mirror 11b is the drive motor 11
Since it is rotationally driven at a constant rotation speed by c, the projection direction of the beam light rotates at a predetermined angular speed along a surface forming a right angle with the guide rail 5. Therefore, the rotating mirror 11
b and the drive motor 11c correspond to scanning means for scanning the light beam in the vertical direction of the work vehicle 1 at a predetermined angular velocity.

The work vehicle 1 is provided with a follow-up sensor 12 as a front-back displacement detecting means for receiving the light beam and detecting a positional deviation in the traveling direction with respect to the guided vehicle 6.
As shown in FIGS. 1 and 2, a pair of follow-up sensors 12 having an elongated shape along the traveling direction of the work vehicle 1 are provided at predetermined intervals in the vehicle width direction and the vertical direction. However, in the vertical cutting guidance described below, the support frames 12a of the pair of tracking sensors 12 rotate 90 degrees around the vertical axis P,
The pair of tracking sensors 12 are separated from each other in the traveling direction for a predetermined period.

Each tracking sensor 12 is formed by arranging a plurality of (for example, 16) light receiving elements in the longitudinal direction, and if the beam light from the beam light source 11 hits the tracking sensor 12,
At least one (for example, 1 to 2) of the light receiving elements is in a state of detecting light. Therefore, for example, the guided vehicle 6 of the work vehicle 1 depends on which light receiving element from the end detects light.
It is possible to detect the positional deviation in the traveling direction with respect to.

That is, as shown in FIG. 4, the rear end of the right side in the traveling direction, that is, the number of the light receiving element from the rear end of the tracking sensor 12 on the beam light source 11 side (light receiving position) is detected. If the distance from the rear end to the central light receiving element is x0, the positional deviation Δx in the traveling direction is Δx = x0−x1. However, in reality, the positional deviation Δx is calculated by the controller 13 mounted on the work vehicle 1 based on the detection value of the tracking sensor 12 (the value corresponding to the light receiving position x1) (see FIG. 6).

Further, the difference Δs (= x1-x2) between the light receiving position x1 of the right following sensor 12 and the light receiving position x2 of the left following sensor 12 in the traveling direction is the azimuth deviation of the work vehicle 1 with respect to the traveling direction. Represents Δs. That is, azimuth deviation Δs
When is zero, the work vehicle 1 is correctly oriented in the direction perpendicular to the light beam, that is, in the traveling direction. This misalignment Δs
Is also calculated by the controller 13.

Further, as shown in FIG. 5, after one (lower side) of the pair of follow-up sensors 12 vertically spaced apart by a predetermined distance d receives the light beam from the beam light source 11. The distance r between the work vehicle 1 and the guided vehicle 6 can be obtained based on the time τ until the other (upper side) receives the light beam. That is, as described above, the light beam is scanned in the vertical direction of the work vehicle 1 at a predetermined angular velocity. Therefore, if this angular velocity is ω, then r≈d / (ωτ). The distance r is calculated by the distance detecting means 13a configured in the controller 13. Furthermore, the set target value R
The difference (distance deviation) Δr (= R−r) from
3 is calculated.

The controller 13 is composed of a microcomputer or the like, and as shown in FIG. 6, a traveling control means 13b is formed inside the controller 13 in addition to the distance detecting means 13a. The traveling control means 13b includes the speed changing motor 1
4 and the travel control solenoid valve 15 are operated such that the positional deviation Δx, the heading deviation Δs, and the distance deviation Δr become zero, in other words, the distance r is a set target value (hereinafter, referred to as a set distance). While maintaining R, the work vehicle 1 travels so that the positional deviation Δx becomes zero.

Before giving a detailed description of the traveling control of the work vehicle 1, a flow chart of the traveling control executed by the controller of the guided vehicle 6 is shown in FIG. 7 to supplement the explanation.
The controller is equipped with a counter for the number of work strokes,
This counter is initialized when the traveling control is started.
Forward or reverse is decided depending on whether the value N of this counter is odd or even. When the end of the traveling range, that is, the end of the stroke is detected, the controller stops the guided vehicle 6, and when a predetermined waiting time has elapsed, the controller increments the counter and then resumes traveling. Therefore, the guided vehicle 6 alternately repeats forward movement and reverse movement within the traveling range of the guide rail 5.

When the value N of the counter becomes larger than the predetermined value Nm, it is judged that the work is completed and the traveling control of the guided vehicle 6 is stopped. For example, as shown in FIG. 1, when the work area AR consists of five work strokes 2, Nm is preset to 5. As described above, the stroke end is detected based on the integrated value of the movement amount and the mark detection information.

While the guided vehicle 6 begins to move forward along the guide rail 5 from left to right in FIG. 1, three forward movements and two reverse movements (five strokes) are alternately repeated, while the work vehicle 1 moves to the position shown in FIG. Forward cutting and backward cutting are alternately repeated along the five work strokes 2 in the work area AR1. In other words, while starting to move forward from the lower left corner of the work area AR and maintaining the distance r in the vehicle width direction with the guided vehicle 6 at the set distance R (= R0), the positional deviation with respect to the guided vehicle 6 in the traveling direction. Run to zero.

When it is detected from the stop of the guided vehicle 6 that the right end of the first work stroke 2 has been reached, the distance between strokes (distance between adjacent work strokes) ΔR is added to the set distance R and the second stroke is also added. After moving the car body up to the second work step, this time, the same running is carried out by rearward cutting. When the forward cutting and the backward cutting are alternately repeated to reach the upper right corner of the work area AR, the work is finished. Hereinafter, description will be added along the flowcharts of FIGS. 8 and 9.

First, in the initial setting (process (a)) after the start of travel control, the value K of the counter for counting the number of strokes is initialized to 1, and the set distance R from the guide rail 5 is the first work stroke 2 Is initialized to a distance R0. This initial distance R0 is input from an operation panel (not shown) of the work vehicle 1 prior to the work. The stroke counter is
Similar to the guided vehicle 6, this is for determining whether to move forward or backward depending on whether the value K is an odd number or an even number (process (b)), and determines the end of the work (process (f)). It is for.

In the processes after (c), the detection signals of the pair of tracking sensors 12 are input, and based on this, the positional deviation Δx in the traveling direction with respect to the guided vehicle 6 is first calculated as described above. It This positional deviation Δx is temporarily stored in the memory in the controller 13 and the previous value Δx
The difference from ₁ , that is, the amount of change (Δx−Δx ₁ ) is obtained.
Then, the positional deviation Δx and its change amount (Δx−Δx ₁ )
Based on the above, the traveling speed control by the PD control is executed.

Specifically, the sign of the positional deviation Δx determines whether to accelerate or decelerate, and the absolute value of Δx and the change amount (Δx-Δ
The speed with which the transmission is operated, that is, the acceleration, is determined in combination with the absolute value of x ₁ ). The traveling speed is increased or decreased by changing the angle of the variable swash plate in the hydraulic pump of the hydrostatic transmission type continuously variable transmission (not shown) by the speed changing motor 14. By switching the rotation direction of the speed changing motor 14, switching between acceleration and deceleration is performed, and the speed of acceleration / deceleration, that is, acceleration is adjusted by adjusting the rotation speed by duty control.

The duty ratio is determined by the combination of the absolute value of Δx and the absolute value of the change amount (Δx-Δx ₁ ), and a table showing the relationship is stored in advance in the memory in the controller 13. Therefore, the traveling control means 1
3a obtains the duty ratio for driving the speed changing motor 14 by referring to this table. By such PD control, it is possible to quickly respond to the change in the positional deviation Δx.

Next, the above-described distance deviation Δr and heading deviation Δs are calculated, and steering control is executed based on these.
Steering of the work vehicle 1 is performed by disengaging only one of the side clutches 3a separately provided in the left and right crawler traveling devices 3, and the traveling control means 13a operates the directional control solenoid valve 15. By switching, the side clutch 3a is operated via the steering cylinder 16.

The directional control solenoid valve 15 is switched between a neutral state, a state in which oil is sent to the left traveling cylinder 16 and a state in which oil is sent to the right steering cylinder 16, whereby forward and leftward movement is possible. Steering and right steering can be switched. For example, when oil is sent to the steering cylinder 16 on the left side, the side clutch 3 of the crawler traveling device 1 on the left side
When a is turned off, the work vehicle 1 is steered to the left.

The traveling control means 13a is a controller 13
By referring to the table stored in the internal memory, the forward movement, the left steering, and the right steering are switched based on the combination of the sign of the distance deviation Δr and the sign of the azimuth deviation Δs.
As a result, the work vehicle 1 travels so that the distance deviation Δr becomes zero, that is, the distance r is maintained at the set distance R.

In the process (d), it is checked whether the guided vehicle 6 has stopped. That is, if the stopped state of the work vehicle 1 that follows the guided vehicle 6 continues for a predetermined time (for example, 3 seconds), it is determined that the guided vehicle 6 has stopped. If the guided vehicle 6 is not stopped, the above-described processing of the traveling speed control and the steering control is repeated, but if the stop is detected, it is determined that the end of the work stroke has been reached and the movement to the next work stroke should be performed ( E) Perform the subsequent processing.

That is, after the stop control, the stroke number counter is incremented. If the value K of the counter does not exceed the preset value Km (5 is set in the example of FIG. 1),
An inter-stroke distance ΔR is added to the set distance R to perform a width-shifting control for moving the work vehicle 1 to the end of the next work stroke.

The width adjustment is performed by repeating forward and backward movement two to three times while alternately disengaging the side clutches 3a of the left and right crawler traveling devices 3. The forward movement and the backward movement are alternately performed within a range in which the tracking sensor 12 receives the beam light from the beam light source 11, and when the distance deviation Δr becomes zero, that is, when r reaches R, the width adjustment is completed. . And
After the attitude is corrected so that the azimuth deviation Δs becomes zero, the traveling is restarted along the next work stroke.

The above control is repeated, and if the value K of the stroke number counter eventually exceeds the set value Km, it is judged that the work is completed and the traveling control of the work vehicle 6 is stopped. In addition to the guidance (horizontal cutting guidance) mode in which the work vehicle 1 travels substantially parallel to the guide rails 5 as described above, the guidance device of the present embodiment travels the work vehicle 1 substantially perpendicularly to the guide rails 5. It has a guidance (vertical cutting guidance) mode.

In the vertical cutting guidance mode, as shown in FIG. 10, the work vehicle 1 travels along the light beam from the light beam source 11. Therefore, the guided vehicle 6 guides the work vehicle 1 by stopping on the guide rail and projecting a beam of light at a predetermined movement pitch (distance between strokes) based on the integrated value of the above-described movement amount. On the other hand, the work vehicle 1 includes a pair of tracking sensors 1
The second support frame 12a is rotated by 90 degrees around the vertical axis P from the state of the lateral cutting guide, that is, the pair of tracking sensors 1
2 travels in a state of receiving a light beam at a predetermined distance in the traveling direction.

The positional deviation (however, the positional deviation in the vehicle width direction) Δx and the heading deviation Δs calculated in the same manner as in the lateral cutting guidance.
Is used for steering control. That is, the traveling control means 13a of the work vehicle 1 determines the sign of the positional deviation Δx and the heading deviation Δx.
Based on the combination with the sign of s, forward, left steering, and right steering are switched. Further, the distance r between the work vehicle 1 and the guidance vehicle 6 calculated in the same manner as in the lateral cutting guidance is used for causing the work vehicle 1 to travel at a constant speed. That is, the traveling control means 13a controls the speed changing motor 14 so that the amount of change in the distance r in each predetermined cycle becomes constant.

The calculated distance r is also used to detect the end of the stroke. That is, the traveling control unit 13a determines that the end of the stroke is reached when the distance r reaches a preset minimum value or maximum value. If the end of the stroke is detected, the work vehicle 1 is moved to the end of the next work stroke by the width-shifting control similar to that for the lateral cutting guidance. However, when the work vehicle 1 reaches the end of the stroke, an ultrasonic signal is transmitted from the work vehicle 1 to the guided vehicle 6, and if the guided vehicle 6 receives this signal, the work vehicle 1 moves sideways before moving. It moves on the guide rail by a predetermined moving pitch ΔR. It should be noted that the illustration of the ultrasonic transmitter provided in the guided vehicle 6 and the ultrasonic receiver provided in the guided vehicle 6 is omitted.

Therefore, in the width-shift control of the work vehicle 1, the pair of follow-up sensors 12 are in a state of once not receiving the beam of light and then receiving the beam of light again, and the positional deviation Δx and the heading deviation Δs become zero. Complete when After this,
Similar to the side-cutting guidance, the forward movement and the backward movement are switched to restart the traveling, and the above control is repeated until the value K of the stroke number counter exceeds the set value Km. The guided vehicle 6 moves by ΔR and stops until the value N of the stroke number counter exceeds the set value Mm, and the operation of scanning the light beam is repeated.

Other examples will be listed below. The distance detecting means for detecting the distance r between the work vehicle 1 and the guided vehicle 6 is not limited to the one that is detected based on the scanning speed of the beam light projected from the beam light source of the guided vehicle 6 as in the above embodiment. Alternatively, for example, an ultrasonic distance sensor may be mounted on the work vehicle 1 as the distance detecting means.

The scanning means for scanning the light beam in the vertical direction of the work vehicle 1 is the rotating mirror 11b as in the above embodiment.
It is not limited to the one using the drive motor 11c and various modifications can be made. For example, a polygon mirror (polyhedral mirror) may be used as the rotating mirror to perform high-speed scanning within a limited angular range in which the work vehicle 1 exists. Alternatively,
The laser projector may be directly driven to rotate without using the rotating mirror.

Although the working vehicle of the above-described embodiment repeats forward cutting and backward cutting alternately, it may be a working vehicle capable of only forward cutting. In this case, when the end of the work stroke is reached, the work piece is turned to move to the start end of the next work stroke instead of moving sideways. Further, it is necessary to rotate the support frames of the pair of tracking sensors 180 degrees with the turning of the work vehicle so that the pair of tracking sensors can always properly receive the beam light.

The present invention is applicable not only to mowing work vehicles but also to guiding various work vehicles such as cleaning work vehicles. Further, the traveling device is not limited to the crawler traveling device as in the above embodiment. For example, in the case of a work vehicle equipped with a traveling device that can steer four wheels, the parallel steering can easily adjust the width from the end of the work stroke to the start of the next work stroke. The work area AR may be provided not only on a sloping ground but on a flat ground, and may be indoors as well as outdoors.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is an overall plan view showing a guide device for a work vehicle according to an embodiment of the present invention.

FIG. 2 is a side view showing a guide device for a work vehicle.

FIG. 3 is a plan view showing an induction vehicle and its guide rail.

FIG. 4 is a schematic diagram showing a method of calculating a positional deviation and an azimuth deviation by a front-back displacement detecting means.

FIG. 5 is a schematic diagram showing a method of calculating a distance between a work vehicle and a guided vehicle by front-rear displacement detection means.

FIG. 6 is a block diagram of traveling control of the work vehicle.

FIG. 7 is a flow chart of driving control of the guided vehicle.

FIG. 8 is a flowchart of traveling control of the work vehicle.

FIG. 9 is a flow chart of traveling control of the work vehicle.

FIG. 10 is an overall plan view showing a vertical cutting guidance mode.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Work vehicle 5 Guide rail 6 Guide vehicle 11 Beam light sources 11b, 11c Scanning means 12 Front-rear displacement detecting means 13a Travel control means

Claims (2)

[Claims] 1. A guide rail (5) installed on the ground side
A guided vehicle (6) is installed that runs at a set speed along
A front and rear displacement detecting means (12) for detecting a positional deviation of the work vehicle (1) in the traveling direction with respect to the guided vehicle (6), and a distance for detecting a distance to the guided vehicle (6) in the vehicle width direction. The work vehicle (1) so that the positional deviation detected by the longitudinal displacement detection means (12) is zero while maintaining the distance detected by the detection means (13a) and the distance detection means (13a) at a set target value. ) Traveling control means (13b)
Work vehicle guidance device provided with and. 2. The scanning means (11b, 11) for scanning the guided vehicle (6) with a light beam in a vertical direction at a predetermined angular velocity.
A beam light source (11) equipped with c) is mounted, and the longitudinal displacement detection means (1) is configured by arranging a plurality of light receiving elements for receiving the beam light in the working vehicle (1) in the traveling direction.
2) are provided in the vertical direction at a predetermined interval apart from each other, and the distance detecting means (13a) is configured such that one of the pair of front-back displacement detecting means (12) receives the light beam and the other receives the light beam. The work vehicle guidance system according to claim 1, wherein the work vehicle guidance system is configured to calculate the distance between the work vehicle (1) and the guided vehicle (6) based on the time until the light beam is received.