JPH01106202A - Steering controller for automatic traveling working vehicle - Google Patents

Abstract

PURPOSE:To rapidly correct the steering of an automatic traveling working vehicle by continuously increasing an objective steering angle every set value during the period when a detecting shear direction based on a steering control sensor is continued in the same direction. CONSTITUTION:The control constitution of the working vehicle is provided with steering hydraulic cylinders 4F, 4R, their control valves 5F, 5R, a control valve 6 and a lawn mower clutch 7 of a hydraulic cylinder 3 of a lawn mower 2, a hydraulic stepless speed change gear 8, and a control device 10 utilizing microcomputer. The control device 10 forms a steering control means 100 for steering front and rear wheels 1 in the correcting direction of a shear from a traveling guide based on the detecting information of a control sensor. When the shear is large, the objective steering angle is continuously increased by a set value every traveling of a set distance even if the working vehicle is operated at a small objective traveling angle during the period when the detecting shear direction based on the steering control sensor is continued in the same direction.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a steering control sensor that detects whether the position of a vehicle body in the width direction is shifted to the left or right with respect to a traveling guide, and Steering control means for steering a steering wheel in a direction to correct deviation with respect to the traveling guide based on information detected by a steering control sensor. Regarding equipment.

[Conventional technology]

The steering control device for this type of autonomous work vehicle described above is configured to detect only the direction of deviation of the vehicle body relative to the travel guide, i.e., to the left or right, and perform steering control. Therefore, it is not possible to control the steering amount directly according to the amount of deviation based on the detection information of the steering control sensor.

Therefore, conventionally, when a deviation is detected, the steering control means is configured to steer the steering wheels to a preset constant target steering angle in a direction to correct the deviation. Was.

However, the target steering angle of the steering wheel is set to a small value in order to prevent the steering control from overshooting when the amount of deviation from the travel guide is small.

[Problem that the invention seeks to solve]

In the conventional configuration described above, since the target steering angle of the steering wheel is set to a constant small value, there is a disadvantage that correction of the deviation is delayed when the deviation with respect to the traveling guide is large.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to enable quick correction of the deviation even when the amount of deviation with respect to the travel guide is large.

[Means for solving problems]

The characteristic configuration of the steering control device for an automatic traveling work vehicle according to the present invention is as follows.

In other words, the steering control means sets a target steering angle each time the vehicle body travels a set distance or at a set time interval (while the direction of deviation detected by the steering control sensor continues in the same direction). The point is that the steering wheel is configured to increase the amount of steering.

[For production]

If the amount of deviation with respect to the travel guide is large, even if the operation is performed at a small target travel angle, the direction of deviation detected by the sensor for the steering side will continue in the same direction, so the direction of deviation detected will be As the vehicle continues in the same direction, the target steering angle is increased by a set amount each time the vehicle travels a set distance or at a set time, and as a result, the vehicle body shifts from the travel guide. If the amount is large, steering can be performed at a large target steering angle.

〔Effect of the invention〕

Therefore, while the detected deviation direction continues in the same direction, the target steering angle is increased by the set amount and the steering is performed, so that it is possible to suppress a delay in correction of the deviation when the deviation amount is large. As a result, even when the amount of deviation is large, it has become possible to quickly correct the deviation while using a simple sensor configuration that detects the direction of deviation with respect to the traveling guide.

〔Example〕

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

As shown in Figures 3 and 4, a pair of left and right front wheels (1F
) and a pair of left and right rear wheels (1R), a lawn mowing device (2) as a working device is suspended on the lower abdomen of the vehicle body (V) so that it can be raised and lowered and stopped, and is used for cutting grass, weeds, etc. The work vehicle that can be used is configured.

In addition, in FIG. 3, (3) is a hydraulic cylinder for raising and lowering the lawn mower (2).

Further, the work vehicle is configured so that it can be driven not only automatically but also by boarding operation in which a worker rides on the vehicle and manually driving the vehicle, or by remote control. As will be described later, by using the remote control configuration, various information during automatic driving can be instructed from outside the vehicle body.

To explain the control configuration of the work vehicle, as shown in FIG. 1, there is a steering hydraulic cylinder (4F) that operates each of the front and rear wheels (1F) and (1R) separately.
, (4R), their control valves (5F), (5R)
, Hydraulic cylinder (3) for lifting and lowering the lawn mowing device (2)
a control valve (6) for the lawn mower (2), an electromagnetically operated clutch (7) that connects and disconnects the drive of the lawn mowing device (2), a hydraulic continuously variable transmission (8) that can switch forward and backward and change speeds in both forward and backward directions.
), its speed change motor (9), and each of the control valves (5F), (5R) based on various travel control information set and stored in advance and information detected by various sensors described below.
(6) A control device (10) using a microcomputer is provided to control the clutch (7) and the variable speed motor (9).

However, the control device (10) is used to correct the deviation of the front and rear wheels (1F) and (1R) as steering wheels relative to the travel guide (described later) based on the detection information of the control sensor (described later). Steering control means (
100) will be constructed.

In Fig. 1, (E) indicates the front and rear wheels (1F), (1
R) and an engine for driving the lawn mower (2), which is operatively connected to the transmission (8).

Further, (11) means that the transmission device (8) is operated during boarding operation.
), and (12) is a speed change arm of the speed change device (8), and neither the speed change motor (9) nor the speed change pedal (11) can operate the speed change device ( 8) is operatively connected to the speed change motor (9) and the speed change pedal (11).

However, the speed change motor (9) is configured to be able to be connected to and connected to the speed change arm (12) on and off using a manually operated clutch mechanism (13).

The clutch mechanism (13) is configured to be turned on and off by a manually operated clutch lever (14) (see FIG. 3). That is, during boarding operation, the clutch lever (14) disconnects the transmission motor (9) and the transmission arm (12), and during remote control or automatic driving, the clutch lever (14) is engaged to disconnect the transmission motor (12). 9) and the transmission arm (12) are linked together.

A clutch switch (SW3) is provided to detect the operating state of the clutch lever (14), and the control device (1O) determines whether a person is on board based on the detection information of this clutch switch (SW,). It is determined whether the vehicle is in a running state in which the vehicle is operated by a person (boarding operation) or in a running state in which no person is on board (automatic driving or remote control).

Note that switching between automatic driving and remote control will be described later.

By the way, the front and rear wheels (1F) and (1R) are the first
As shown in the figure, the front and rear wheels (1F) and (1R) are steered in the same phase because each wheel is configured to be able to be steered independently so that it functions as a steering wheel as well as a driving wheel. Three types of steering systems can be selected: a parallel steering system that steers the vehicle in opposite phases, a four-wheel steering system that steers the vehicle in opposite phases, and a two-wheel steering system that steers only the front wheels (1F).

During remote control, the configuration is such that the parallel steering type and the four-wheel steering type can be switched by remote control, and during boarding operation, any one of the three types of steering types can be used, although the explanation will be omitted. Selective use available.

However, during automatic driving, the above parallel steering type and 4
The system is configured to automatically switch between the wheel steering type and the wheel steering type.

Next, various sensors equipped on the work vehicle will be explained.

As shown in FIGS. 3 and 4, a pair of left and right tracing sensors (s1) detect deviations in the width direction of the vehicle body from the boundary between the uncut area (B) and the cut area (C); ('sz)
However, four sensor support arms (15
) is provided at each tip.

In other words, the boundary (L) between the uncut land (B) and the cut land (C)
) corresponds to the traveling guide, and the pair of copying sensors (S
l) and (St) correspond to a steering control sensor that detects whether the position of the vehicle body (V) in the width direction is shifted from the driving guide to the left or right.

Each of the copying sensors (Sl) and (SZ) includes a pair of light projecting section and a light receiving section, which face each other in the vehicle width direction, and the light directed from the light projecting section to the light receiving section is directed toward the light receiving section. The unmown area (B
) or a mown field (C), respectively.

However, as the vehicle body (V) moves forward, uncut grass passes intermittently between the light projecting section and the light receiving section.
The light receiving section will intermittently output signals corresponding to the presence and absence of grass.

Therefore, the discrimination between uncut land (B) and mowed land (C) by the scanning sensors (Sl) and (sz) is based on, for example, information obtained by integrally processing the output signal from the light receiving section. Become.

During automatic driving, one of the four sets of copying sensors (Sl) and (St) provided at both the front and rear ends of the vehicle body is located on the front side with respect to the vehicle traveling direction and on the boundary (L) side. One set is used to determine the deviation in the width direction of the vehicle body with respect to the boundary (L).

To explain the determination of the deviation in the width direction of the vehicle body with respect to the boundary (L), the pair of copying sensors (Sυ,
(SZ), the tracing sensor (Sl) on the outside of the vehicle body detects the mown area (C), and the tracing sensor (SZ) on the inside of the vehicle body detects the unmoved area (B). A state in which there is no deviation from the boundary (L) is determined to be a state in which there is no deviation from the boundary (L).

In other words, when the pair of copying sensors (S1) and (SZ) both detect the unmoved area (B), the vehicle body (V) is on the unmoved area (B) side with respect to the boundary (L). The case where it is determined that the area is off to
It will be determined that it has shifted to the C) side.

As shown in Fig. 1 and Fig. 3, the orientation of the geomagnetic sensor is used to detect the orientation of the vehicle body relative to a preset reference orientation based on the length direction of the working stroke as the length direction of the traveling guide. A sensor (S,) is attached to the rear end of the vehicle body.

As shown in FIG. 1, a rotation speed sensor (S4) is provided which is rotationally driven by the output of the transmission (8) and outputs a set number of pulse signals per unit rotation speed. Based on the distance traveled by the vehicle body (V), the distance traveled by the vehicle body (V) is detected.

Also, a potentiometer (Ro) for detecting the target steering angle using the steering handle (H) for boarding operation.
, a potentiometer (R,) for detecting the steering angle of each of the front and rear wheels (1F) and (1R).

(R2) and a vehicle speed detection potentiometer (R3) that indirectly detects the vehicle speed by detecting the operating state of the transmission (8).

In Fig. 1, (16) is a transmitter for remote control, and (17) is a transmitter for remote control.
) is a receiver that receives the instruction information, and is configured to input the received information to the control device (10).

To explain the transmission a (16), as shown in FIG. 2, there is a steering lever that instructs the target steering angle during remote control by moving left and right, and instructs to switch the steering type used by moving back and forth. (18),
A shift lever (19) that switches between forward and backward motions and instructs the vehicle speed in both forward and backward motions, a switch (20) for raising and lowering the lawn mowing device (2), and a switch (20) for switching on and off the drive of the lawn mowing device (2). A clutch switch (21) that instructs to switch the working device between an operating state and a stopped state, a start switch (22) that instructs the start of automatic driving, a turn switch (23) that instructs the start of a turn, and the vehicle body (V ) are provided with work end switches (24) for instructing to stop the work and end the work.

In FIG. 2, (25) indicates that the work vehicle is connected to the transmitter (1).
6) The first mode of artificial remote control (“'0゛)”
and a second mode ("1") for remotely giving auxiliary instructions such as instructions to start or stop the work vehicle during automatic travel.

In other words, this radio control mode switching switch (25
), the transmitter (16) can instruct switching between remote control and automatic driving.

Although not shown in the drawings, there are various sensors that detect the operation status of each of the levers and switches, and various devices for transmitting modulated information on the detected information and transmitting the modulated information to the receiver (17). will be established.

Next, automatic driving of the work vehicle will be explained.

As shown in Fig. 5, a plurality of work strokes lined up in the width direction of the vehicle body are set, with the section from the - side to the opposite side of the rectangular uncut land (1'l) being regarded as one work stroke, and, In each work process, it automatically travels along its length, and as it reaches the end of one work process, it moves to the start of the next work process adjacent to that work process, repeating turns. By reciprocating the work process, the lawn mowing work in a predetermined range is automatically performed.

However, in this embodiment, as will be described in detail later, the work area is surrounded by a rectangular uncut area (B) surrounded by an already cut area (C).
) This makes it possible to start automatic driving immediately from the first work process without having to divide the process into sections. In other words, the reference distance for the work process is automatically set based on the travel distance in the first work process, and each time the work vehicle travels the set reference distance, the work process is automatically set for the next work process. I'm trying to make a turn.

Further, the working vehicle is configured to travel back and forth through a plurality of working strokes while switching between forward and backward movement for each stroke, and therefore, the turn to move to the next working stroke is made as the vehicle travels the reference distance. , in the forward or reverse state, the vehicle is moved widthwise toward the starting end of the next work stroke without changing the direction of the vehicle body, and then the vehicle is switched between forward and backward motion.

The control operation for automatically driving the work vehicle will be described in detail based on the flowchart shown in FIG.

First, the clutch lever (14) is engaged to link the transmission (8) and the transmission motor (9), and the radio control mode changeover switch (25) of the transmitter (16) is turned on. After switching to the second mode selection state, the start switch (22) of the transmission a (16)
This will instruct the start of automatic driving. Then, the turn start in the first working process is performed by the transmitter (16).
), and the end of the work, that is, stopping of running, is given with the work end switch (24).

Upon receiving the instruction to start traveling, the direction sensor (
After setting and storing the direction detected by step S3), that is, the direction of the vehicle body at the time of start of travel, as the reference direction for the first working process, the transmission (8) is operated so that the traveling speed becomes the set speed, and the vehicle is in the forward or forward state. By starting traveling in reverse and controlling the steering so that the direction detected by the direction sensor (S3) is within the set fuwawa zone with respect to the reference direction, the machine moves along the length direction of the work process. The vehicle will be driven automatically.

In other words, as mentioned above, the planned work area is a rectangular uncut area (
If work is started without dividing the land into section B), in the first work process, the boundary (L) between the uncut land (B) and the cut land (C) is not formed, so the The boundary (L) is detected using the detection information of the sensors (S1) and (52).
Since it is not possible to determine the deviation in the width direction of the vehicle body relative to the vehicle width direction, automatic driving is performed only by azimuth control that controls the traveling direction of the vehicle body using only the information detected by the azimuth sensor (S3).

However, as shown in FIG. 5, in each work process after this first work process, as the mowing work by the lawn mowing device (2) progresses, the unmown area (B) and the mown area are separated. Since a boundary (L) with (C) is formed, the direction is controlled based on the information detected by the direction sensor (S3) so that the machine automatically travels in the direction of each work process while avoiding uncut leaves. Steering control is performed by using both of the above-mentioned scanning control based on the detection information of the scanning sensors (S1) and (SZ).

The details of the orientation control and the tracing control will be described later.

After the start of travel, the receiver (1
Based on the received information in step 7), it is determined whether or not an instruction to start a turn has been received, and when the instruction to start a turn is received, the start of running detected by the rotation speed sensor (S4) is determined. After setting and storing the traveling distance from the point to the time when the turn start signal is received as the reference distance for each work process after the first work process, turn control to move to the next work process is started.

After turning for the next work process, the travel distance detected by the rotation speed sensor (S4) reaches the set and memorized reference distance, or the work from the transmitter (16) is completed. As described above, the copying sensor (
Steering control is performed based on S1), (Sz) and the detection information of the orientation sensor (S,).

When the travel distance of the work vehicle reaches the reference distance, the vehicle is turned for the next work process,
When the instruction to finish the work is received, the work is finished and the vehicle stops running.

To explain the orientation control, the orientation sensor (S
If the detected orientation in step 3) deviates from the reference orientation, the front and rear wheels (1F), (
1R) to a set angle, the vehicle orientation is corrected by performing a process to return the vehicle to a neutral steering state as a single control sequence.

To explain the copying control, the copying sensor (S
+), (SZ), when it is detected that the position in the width direction of the vehicle body deviates from the boundary (L) to the left or right, the front and rear wheels (1F ) and (1R) in the same phase to correct the position in the vehicle width direction.

However, if the deviation from the boundary (L) continues in the same direction, the front and rear wheels (1
F), the target steering angle (θn) of (1R) is increased by a set amount for steering, so that even if the amount of deviation is large, the deviation can be quickly corrected.

To explain, as shown in FIG. 7<4) and (0), a pair of scanning sensors (S) located on the boundary (L) side
+) and (Sz) are read to determine the correction direction.

If the correction direction is toward the unmoved land (8) (IN), information on determining whether the boundary (L) is on the left or right side with respect to the vehicle body (V) and the vehicle body (V) are provided. When the target steering angle (θn) of the front and rear wheels (1F) and (1R) is increased by a set amount based on the information on the direction of travel, whether the vehicle is traveling forward or backward. Upper limit value (θno
) is set to ±7 degrees, and then the setting path M (d) for setting the time point at which the target steering angle (θn) is increased is set to 25 degrees.
Set to c++++.

When the correction direction is on the mowed land (C) side (OUT), the boundary (L) is on the vehicle body (V) in the same way as when the correction direction is on the uncut land (B) side. The upper limit value (θno) is set to ±10 based on the information for determining whether the vehicle body (V) is on the left or right side of the vehicle and the information for determining the direction of travel whether the vehicle body (V) is running forward or backward. and the set distance (d) is set to 20 cm.

In other words, when the vehicle body (V) shifts toward the mowed land (C) side with respect to the boundary (L) and corrects it toward the unmown land (B) side, in order to reduce the unevenness of the mowing marks, Increasing the target steering angle for each long set distance and steering to a large angle to prevent uncut areas from being deviated to the unmoved area (B) side and corrected to the mowed area (C) side. In addition, while increasing the target steering angle for each short set distance, the steering is made to a smaller angle than when correcting to the uncut land (B) side.

Then, whether the correction direction with respect to the boundary (L) is to the left or right with respect to the vehicle body (V), the target steering angle (θn) and the upper limit value (θno) for the target steering angle (θn)
The target steering angle (θn
) is in a range smaller than the upper limit value (θno).

If the target steering angle (θn) is within a range smaller than the upper limit value (θno), it is determined whether the vehicle has traveled a set distance (d) set corresponding to the correction direction as described above. When the vehicle has traveled the set distance (d), the target steering angle (θn) is increased by the set angle (1 degree), and then the detected value of the travel distance is cleared.

However, the target steering angle (θn) is set as a positive value when the correction direction is to the right of the vehicle body, and is set as a negative value when the correction direction is to the left of the vehicle body. When the correction direction is to the left of the vehicle body, the actual target steering angle is increased by subtracting the set angle (1 degree) from the target steering angle (θn).

Further, if the target steering angle (θn) has a sign opposite to the correction direction, it is determined that the deviation direction has been reversed, and in order to prevent control overshoot,
The target steering angle (θn) is set to zero to return to a neutral steering state.

On the other hand, if there is no deviation from the boundary (L) and there is no need for correction, the currently set target steering angle (
Based on whether or not θn) is set to zero, that is, the steering is in a neutral state, it is determined whether or not the steering operation is being performed, and if the steering operation is being performed, the vehicle body (V) is The target steering angle (θn) is adjusted so that the target steering angle (θn) is decreased by a set angle (1 degree) toward the steering neutral side each time the vehicle travels.
After adding or subtracting the target steering angle (θn) and the set angle (1 degree) based on whether n) is set to a positive or negative value, the detected value of the traveling distance is cleared.

After the target steering angle (θn) is set, the steering angle detection potentiometer (R1),
(R2), the steering angle of each of the front and rear wheels (1F) and (1R) is detected, and the steering angle and the target steering angle (
so that the deviation from θn) is within the set dead band (2 degrees).
The hydraulic cylinder for the steering (4F), (4
The steering valve for the control valve (R), that is, the control valve (5
F) and (5R) are driven in the left-right direction, so that each of the front and rear wheels (1F) and (1R) faces in the direction of the set target steering angle (θn) in a parallel steering type. This is how the steering is controlled.

Therefore, this tracing control process is performed based on the detection information of the pair of tracing sensors (Sυ, (St) as the steering control sensors), the front and rear wheels (1F) as steering wheels,
This corresponds to the steering control means (100) that steers (1R) in a direction that corrects the deviation with respect to the boundary (L) as the traveling guide.

To explain the turn control, as described above, the work vehicle repeats forward and backward movement and travels a set distance at the maximum turning angle using the parallel steering type in order to travel back and forth during each work stroke. As a result, after moving towards the next working stroke side, the forward and backward movement is switched.

[Another example]

In the above embodiment, the direction control is performed in a four-wheel steering style based on the detection information of the direction sensor (S3), and the steering control sensor corrects the direction of the vehicle body (V) with respect to the length direction of the traveling guide. Both the front and rear wheels (1F) and (1R) are steered in a parallel steering manner based on the detection information of a pair of tracing sensors (St) and (St), and the uncut ground is used as a driving guide. (B) and the case where the steering control is performed in combination with the tracing control that corrects the position of the vehicle body (V) in the width direction with respect to the boundary (L) between the mown area (C) and the mowed area (C) is illustrated. Direction control is performed on the front wheel (1F) or the rear wheel (
The direction sensor (S,) and the tracing sensor (St), so as to steer the vehicle using a two-wheel steering system in which one of the wheels (1R) is steered, or to simultaneously correct the direction of the vehicle body and the position in the width direction.
(Based on the rain detection information of Suri, the front wheels (1F), (
The vehicle may be steered with a difference between the target steering angles of 1R). Alternatively, the steering control may be performed using only the tracing control. However, in that case, the steering operation will be performed using a steering type such as a two-wheel steering type that can simultaneously correct the position of the vehicle body direction and the width direction.

Further, in the above embodiment, when the direction of detection deviation with respect to the boundary (L) continues in the same direction, the vehicle body (ν) is at the set distance (d).
Although the target steering angle (θn) is increased by a set amount each time the vehicle travels, the target steering angle (θn) may be increased each time a set time elapses.

In addition, in the above embodiment, the forward and backward movement is repeated for each stroke,
Although we have illustrated a case in which the vehicle travels back and forth through multiple work strokes, for example, each time the vehicle travels a set reference distance, the direction of the vehicle body is reversed by 180 degrees and the vehicle is moved to the next work stroke. Various changes may be made to the traveling mode and the specific configuration of the control means for moving to the next work process.

Further, in the above embodiment, the present invention is applied to a work vehicle for mowing lawns, and in the first working process, the vehicle is operated to travel in a reference direction that is set based on the orientation of the vehicle body at the time of starting travel. control, and in the subsequent work process,
The driving direction is the reference direction, and the vehicle automatically travels along the boundary (L) between the unmoved area (B) and the mowed area (C).
Although the case where the steering is controlled so that both the direction of the vehicle body and the width direction of the vehicle body are in the appropriate state has been exemplified, the present invention can be applied to various types of work vehicles, and the present invention can be applied to various types of work vehicles. The specific configurations of the working device and the working vehicle, as well as the specific configurations of each means for automatically driving the working vehicle along the travel guide, can be changed in various ways.

Incidentally, it is possible to project a guiding beam or the like in the length direction of the working stroke and use the beam as a traveling guide. Further, in a work vehicle such as a chemical spraying work vehicle that travels along trees, a row of trees located on the lateral side of the vehicle body can be used as a traveling guide.

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 by the reference numerals.

[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 structure, FIG. 2 is a front view of the transmitter, and FIG. Figure 4 is the same plan view, Figure 5 is an explanatory diagram of the work area, Figure 6 is the overall side view of
The figure is a control flowchart for automatic driving, Figure 7 (a), (
0) is a flowchart of steering control. (V)...Vehicle body, (L)...Driving guide, (S1), (St)...Sensor for steering control, (1F), (1R) ...Steering wheel, (1
00)...Steering control means.

Claims (1)

[Claims] Steering control sensors (S_1) and (S_2) that detect whether the position of the vehicle body (V) in the width direction is shifted to the left or right with respect to the traveling guide (L), and the steering control sensor Based on the detection information of (S_1) and (S_2), the steering control means (100 ), the steering control means (100) is configured such that the direction of deviation detected by the steering control sensors (S_1) and (S_2) is in the same direction. During this period, the automatic driving work vehicle is configured to increase the target steering angle (θ_n) by a set amount each time the vehicle body (V) travels a set distance or every set time and steers the vehicle. steering control device.