JPH0572601B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention provides imaging means for imaging the boundary between an untreated work area and a treated work area, and based on the imaging information of the imaging means, The present invention relates to a steering control device for an automatic traveling work vehicle, which is provided with a steering control means for controlling the steering so that the vehicle automatically travels along the boundary.

[Prior Art] The above-mentioned steering control device for an automatic traveling work vehicle detects the boundary between an untreated work area and a treated work area by image processing image information, and
The system controls the steering so that the vehicle automatically travels along the detected boundaries.

Conventionally, in order to be able to detect the positional relationship of the vehicle body with respect to the boundary before the vehicle travels, the imaging means is configured to image the boundary located on the front side with respect to the direction of travel of the vehicle body. It was installed with the imaging field of view facing toward the direction of travel of the vehicle body.

By the way, in the first work process, since the boundary between the untreated work area and the treated work area is not formed, steering control cannot be performed based on the image information of the imaging means. In the first work process, the work is performed by manually driving the work vehicle, and in the subsequent work process, the boundaries formed as the work is performed by artificially driving the work vehicle are used. It was designed to control the steering.

[Problems to be Solved by the Invention] However, the above-mentioned conventional configuration has a disadvantage in that automatic travel cannot be performed from the first working process.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to enable automatic travel from the first work process where the boundary between the untreated work area and the treated work area is not formed. It's about doing.

[Means for solving problems]

A characteristic configuration of the steering control device for an automatic traveling work vehicle according to the present invention is that the steering control means is controlled based on information obtained by imaging the front side of the vehicle body with respect to the traveling direction of the vehicle body by the imaging means. The structure is such that it can be freely switched between the state and the state in which steering control is performed based on information obtained by imaging the rear side, and its functions and effects are as follows.

[Effect]

In other words, in the first work process where the boundary between the untreated work area and the treated work area has not yet been formed,
As the vehicle advances, a boundary is formed behind it. Therefore, by imaging the boundary formed on the rear side in the direction of travel as the vehicle moves forward, and controlling the steering based on the image processing, it is possible to control the progress of the vehicle even during the first work process. This allows the vehicle to automatically travel along the boundaries that are formed accordingly.

Incidentally, in the work process after the boundary is formed in the first work process, steering control can be performed as usual based on information obtained by imaging the front side with respect to the vehicle traveling direction.

〔Effect of the invention〕

Therefore, even in the first work process where the boundary between the untreated work area and the treated work area has not been formed,
We have now been able to make it run automatically.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

As shown in FIGS. 4 and 5, a pair of left and right front and rear wheels 1 and 2 are provided, each of which can be steered freely, and a lawn mowing device 3 is suspended on the lower abdomen of the vehicle body V so as to be movable up and down. This constitutes a work vehicle used for cutting grass and weeds.

In addition, the boundary L between the untreated work area B and the treated work area C
Image sensor S ₁ as an imaging means to take an image of
, a boundary L located on the front side with respect to the vehicle body V
As will be described later, the front and rear wheels 1 and 2 are steered to control the front and rear wheels 1 and 2 based on the image information obtained by the image sensor S ₁ to move the vehicle body V toward the boundary L. It is designed to be able to run automatically along the route.

However, the image sensor _S1 detects whether the vehicle body V is properly aligned with the boundary L, whether the boundary L is located on the right side or the left side of the vehicle body V. It is provided so as to be slidable in the lateral direction of the vehicle body so that an image can be taken with the boundary L positioned at the center of the imaging field of view in a state in which the image capturing field is in the horizontal direction of the vehicle body.

That is, the slide rail 4 is attached to the front upper part of the vehicle body, and the sensor support member 5 is supported movably on the slide rail 4 in the width direction of the vehicle body. The image sensor _S1 is attached to the vehicle body, and the position of the sensor support member 5 in the width direction of the vehicle body can be changed by a slide motor 6.

Further, in order to detect the traveling distance of the vehicle body V,
A distance sensor _S2 that outputs a predetermined number of pulse signals per unit traveling distance is provided so as to be rotationally driven by a driven wheel 7 provided at the rear of the vehicle body V.

To explain the structure of the vehicle body V, as shown in FIG. 1, there are hydraulic cylinders 8 and 9 for steering to operate the front and rear wheels 1 and 2 separately, and
In addition to providing control valves 10 and 11 for this,
A hydraulic continuously variable transmission device 12 that can freely switch between forward and reverse directions and can change speeds in both forward and backward directions is interlocked with the engine E, and a speed change motor 13 is interlocked with a speed change arm 14 of the speed change device 12.

Also, steering position detection potentiometers R ₁ and R 2 that detect the steering positions of the front and rear wheels 1 _{and 2} , respectively, and a shift position detection potentiometer that detects the operation position of the transmission 12.
R ₃ is provided, and the vehicle body V is controlled to automatically travel along the boundary L based on the detection information thereof, the detection information of the image sensor S ₁ , and the detection information of the distance sensor S ₂ . A control device 15 is provided which also serves as the steering control means 100.

In the figure, H is a steering handle for boarding operation, _R0 is a potentiometer for detecting its operation position, and 16 is a speed change pedal for boarding operation.

Describing the image processing for detecting the boundary L between the untreated working area B and the treated working area C based on image information from the image sensor _S1 , the unprocessed working area C is larger than the untreated working area C. Utilizing the phenomenon that work area B appears brighter than work area B, the captured image information is subjected to differential processing and binarized based on the magnitude of the change in brightness, thereby extracting parts with large changes in brightness and darkness. Then, for example, by Hough transform processing, etc., a straight line connecting the extracted portion in the vertical direction, that is, in the perspective direction with respect to the traveling direction of the vehicle body V is determined, and the position and inclination of this straight line in the width direction with respect to the center of the visual field are determined. By this, the boundary L
The position and inclination of the vehicle body V in the width direction relative to the vehicle body V are determined.

That is, by steering the front and rear wheels 1 and 2 so that the position and inclination of the vehicle body V with respect to the boundary L detected in the process described above become zero, the vehicle body V automatically moves along the boundary L. The vehicle is steered as if it were moving.

Incidentally, when correcting the position in the width direction with respect to the boundary L, the front and rear wheels 1 and 2 are steered in the same direction to move the vehicle body V in parallel. When correcting the inclination of the steering wheel, use a two-wheel steering type that changes the direction of only one of the front and rear wheels 1, 2, or a four-wheel steering type that changes the direction of the front and rear wheels 1, 2 in the opposite direction. This operation causes the vehicle body V to turn.

Next, while explaining the operation of the control device 15 based on the flowchart shown in FIG.
The steering control means 100 for automatically driving the vehicle along the boundary L between the untreated work area B and the treated work area C that is formed as the lawn mowing work progresses will be described in detail.

In other words, automatic driving, as shown in Figure 3,
This is carried out by setting the untreated work area B adjacent to the treated work area C as the work area, and
Work is performed in a reciprocating manner from one side of the untreated work area B to the opposite side. Then, as information for performing automatic driving, the distance in the longitudinal direction of the untreated work area B is set in advance as a reference travel distance for one work process, and the width of the untreated work area B part is set in advance as the distance in the longitudinal direction of the untreated work area B. The number of work strokes obtained by dividing by the work width of the device 3 is set in advance as the planned number of work strokes.

By the way, in the first process, which is the first work process, the boundary L between the untreated work area B and the treated work area C is
has not yet been formed,
In addition, even if a treated work area C is formed, there is a risk that its boundary L may be unclear, so if it is left as it is, the image information will not be processed by the image sensor S ₁ attached to the front of the vehicle body V. It is not possible to control the steering using the steering wheel.

Therefore, by making effective use of the structure that allows the vehicle body V to travel in either forward or reverse mode with no difference, work is performed in the reverse mode only during the first stroke. However, in the working strokes after the second stroke, the boundary L is formed by traveling in the immediately preceding working stroke, so the boundary L formed in the previous stroke is used to drive the vehicle in a forward state.

That is, before starting work, first, the front and rear wheels 1,
2 is maintained in a neutral steering state, and based on the detection information by the distance sensor _S2 , until the boundary L is captured within the field of view of the image sensor _S1 , Go straight the set distance.

After moving straight back by the set distance, the image sensor S ₁ starts imaging to image the boundary L portion formed as the vehicle body V advances, and
As mentioned above, based on the imaging information, the position and inclination of the vehicle body V with respect to the boundary L are determined, and
Based on the obtained information, steering control is performed so that the vehicle body V moves straight along the boundary L.

Next, based on the information detected by the distance sensor S ₂ , it is determined whether or not a predetermined distance has been traveled, thereby determining whether or not the first stroke has been completed. , as described above, the steering control performed based on the imaging information by the image sensor _S1 is repeated.

As the first stroke ends, the front and rear wheels 1,
2 in the same direction, move the set distance in parallel toward the second stroke direction, then switch to forward mode and move the set distance straight, to the starting end side of the second stroke. Carry out a turn that brings the vehicle body V closer to its width.

When the turn is completed, the second stroke starts traveling in a forward state, and similarly to the first stroke, the vehicle travels a predetermined distance, that is, a distance corresponding to one working stroke, based on the information detected by the distance sensor _S2 . By repeating the steering control based on the image information from the image sensor S ₁ until the vehicle body V
is controlled so that it moves straight along the boundary L formed in the first stroke.

As the traveling of one work stroke is completed, it is determined whether all the work strokes have been completed based on the preset number of work strokes, and if all the work strokes have been completed, the traveling is stopped. The work will then be completed.

If all work strokes have not been completed, turn the vehicle body V 180 degrees toward the untreated work area B, move the vehicle V to the starting end of the next work stroke, and then proceed as usual. , the steering control based on the imaging information obtained by the image sensor S ₁ in the forward movement state is repeated.

By the way, for each work process, the untreated work area B
Since the running direction of the vehicle body V is reversed by 180 degrees, the position of the boundary L with respect to the vehicle body V in the second stroke or even stroke is reversed left and right in the second stroke and subsequent odd-numbered strokes. Therefore, the second
After the stroke, after turning 180 degrees, the left and right positions of the image sensor _S1 with respect to the vehicle body V are switched.

Thus, the steering control means 100 is controlled based on information obtained by imaging the front side with respect to the traveling direction of the vehicle body V by the image sensor _S1 , and based on information obtained by imaging the rear side with respect to the traveling direction of the vehicle body V. It is configured such that it can be freely switched between a state in which steering control is performed.

However, in the first stroke, since the vehicle body V is running in reverse and the image sensor _S1 is in a state where it images the boundary L in a backward direction,
The vehicle body V relative to the boundary L obtained from the imaging information
Since the direction of deviation in the position and direction in the width direction of the vehicle is left and right reversed with respect to the actual traveling direction of the vehicle body, only the steering control in the first stroke is based on the image information of the image sensor _S1 . The direction is reversed left and right. In addition, from the second stroke onward, the vehicle body V runs only in the forward state as usual, so the steering direction based on the image information of the image sensor _S1 is used as is.

[Another example]

In the above embodiment, the steering control means 100 is controlled based on information obtained by imaging the front side with respect to the traveling direction of the vehicle body V by the image sensor _S1 , and information obtained by imaging the rear side with respect to the traveling direction of the vehicle body V. The imaging direction of the image sensor _S1 is switched by switching between a state in which the vehicle body V is moved forward in the direction of travel and a state in which it is moved backward. For example, image sensors S ₁ may be provided at the front and rear of the vehicle body V, and the front and rear image sensors S ₁ may be switched and used when moving forward and backward, or one image sensor S 1 may be used. ₁ may be moved in the longitudinal direction with respect to the vehicle body V, and the imaging direction may be switched between a state facing the front side of the vehicle body and a state facing the rear side of the vehicle body,
The specific configuration for switching the imaging direction of the image sensor S ₁ and the specific configuration of the steering control means 100 can be changed in various ways.

Further, in the above embodiment, a case was illustrated in which the vehicle body V was made to travel back and forth, but the present invention is also applicable, for example, to a case where the vehicle body V is moved back and forth along the outer periphery of an untreated work site B surrounded by a treated work site C. The present invention can also be applied to the case of running in a rotary mowing mode, and the working style and the specific structure of the running style can be changed in various ways.

Further, in the above embodiment, the case where the working vehicle is configured as a lawn mowing working vehicle is illustrated, but the present invention can be applied to various working vehicles, and the specific configuration of each part can be changed in various ways.

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of the drawing]

The drawings show an embodiment of the steering control device for an automatic traveling work vehicle according to the present invention, FIG. 1 is a block diagram showing the control configuration, FIG. 2 is a foot chart showing the operation of the control device, and FIG. FIG. 4 is a schematic plan view of the working vehicle, and FIG. 5 is a side view of the same. B... Untreated working area, C... Treated working area, L
... Boundary, V ... Vehicle body, S ₁ ... Imaging means, 100
...Steering control means.

Claims (1)

[Claims] 1 Boundary L between untreated working area B and treated working area C
An imaging means S ₁ is provided for taking an image of the vehicle, and a steering control means 100 is provided for controlling the steering so that the vehicle body V automatically travels along the boundary L based on the imaging information of the imaging means S ₁ . A steering control device for an automatic traveling work vehicle, the steering control means 100
into a state in which steering control is performed based on information obtained by imaging the front side with respect to the traveling direction of the vehicle body V by the imaging means _S1 , and a state in which steering control is performed based on information obtained by imaging the rear side with respect to the traveling direction of the vehicle body V. A steering control device for an automatic driving work vehicle that is configured to be switchable.