JPH01180013A - Working vehicle with steering controller - Google Patents

Abstract

PURPOSE:To discriminate the waviness condition of a border during the traveling of a first setting distance by storing a value to correspond to a steering angle in each traveling of a second setting distance, which is set to be shorter than the first setting distance, or in each setting time. CONSTITUTION:Sensors S1 and S2 for steering control detect whether the position of a vehicle body V in a width-wise direction is dislocated in a right direction or a left direction to a border L between an unprocesses working place B and a processed working place C. Then, based on the detecting information of the sensors S1 and S2, a steering control means 100 steers steering wheels 1F and 1R in a direction to correct the dislocation to the border L. The value to correspond to the steering angle in each traveling of the vehicle body V in the second setting distance, which is set to be shorter than the first setting distance, or in each setting time is stored in a storing means 101 and based on storing information, a discrimination means 102 can discriminate the waviness of the border L.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention detects whether the position of a vehicle body in the width direction is shifted to the left or right with respect to the boundary between an untreated work area and a treated work area. and steering control means for steering the steering wheel in a direction to correct the deviation with respect to the boundary based on the detection information of the steering control sensor. The direction control means adjusts the steering angle of the steering wheel by a set amount every time the vehicle body travels a set distance or every set time while the direction of deviation detected by the turning direction control sensor continues in the same direction. The present invention relates to a work vehicle with a steering control device that is configured to perform steering in an incremental manner.

[Conventional technology]

This type of work vehicle with a steering control device described above is used in a form that automatically travels along the boundary between untreated work areas and treated work areas so that work within a predetermined range of work areas can be performed automatically. It is something that

For example, in the case of automatically driving a lawn mowing work vehicle, every time one work process is completed, it is moved to the starting point of the next work process in the direction that intersects with that work process. There is a round trip type and a so-called reciprocating type in which the machine is moved to the next adjacent work process in parallel to the previous work process every time one work process is completed. Note that the movement to the starting end of the next working process upon completion of one working process is automatically performed, for example, based on a turn pattern that is set and stored in advance.

By the way, when making a work vehicle automatically travel along a boundary,
If the boundary track is followed accurately, for example, in the case of a work vehicle for mowing lawns, the mowing work width can be effectively utilized, and work efficiency can be improved.

For this reason, conventionally, while the direction of deviation detected by the steering control sensor continues in the same direction, the steering control means is operated to control the steering wheels every time the vehicle body travels a set distance or at every set time. By configuring the steering to increase the steering angle by a set amount, even if the deviation from the boundary becomes large, it is possible to quickly return to the proper state, and the steering angle can be adjusted accurately against the boundary. I am making it possible to follow.

[Problem to be solved by the invention]

By the way, when the steering control sensor detects a deviation from the boundary and steers the steering wheel in a direction to correct the deviation, there is a delay in the control response, as in boat fishing. It is inevitable that a time delay will occur before the work vehicle converges to properly align with the boundary.

Therefore, if there is an undulation at the boundary, there is a possibility that the undulation at the boundary increases as the work progresses.

By the way, during lawn mowing work, there may be a local area where there is no grass as an untreated work area, and as a result, that area is considered to be a treated work area, and as a result, the boundary This results in undulations.

If you attempt to accurately track a undulating boundary, the undulations at the boundary tend to increase due to control delays in steering control, which may make it difficult to properly follow the boundary. be. Further, an increase in the undulation of the boundary has the disadvantage that the aesthetic appearance of the work trace becomes poor.

By the way, when the undulation of the boundary increases, the steering wheel becomes more frequently steered from the neutral steering state corresponding to the straight-ahead state to the left or right in order to follow the undulating boundary.

Therefore, if we focus on the ratio of the distance traveled with the steering wheel in the neutral state and the distance traveled while the steering wheel is being operated during one work process, if the undulations are large, the distance traveled with the steering wheel in the neutral state will be lower. The distance traveled while operating the steering wheel becomes longer than the distance traveled.

Therefore, it may be possible to determine the size of the boundary undulation based on the ratio between the distance traveled in a neutral steering state and the distance traveled while operating the steering wheel. As shown in Figure 11, the boundary (L) between the untreated work area (B) and the treated work area (C) is determined by determining the ratio between the distance traveled and the distance traveled in the neutral steering state. The ratio is the same whether the width of the undulation is large (indicated by the broken line in the figure) or small (indicated by the solid line in the figure), making it difficult to quantitatively determine the size of the undulation. is desired.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to accurately detect the undulation state of the boundary so that when the undulation of the boundary increases, the undulation can be corrected. The purpose is to do so.

[Means to solve the problem]

A characteristic configuration of the work vehicle with a steering control device according to the present invention is such that while the vehicle body travels a first set distance, the vehicle body travels a second set distance that is set shorter than the first set distance. A storage means for storing a value corresponding to the steering angle each time the steering angle is rotated or for each set time, and a waviness determination means for determining the waviness of the boundary based on the stored information in the storage means. Its actions and effects are as follows.

[For production]

This is because the steering control means is configured to increase the steering angle of the steering wheel by a set amount and perform steering while the direction of deviation detected with respect to the boundary by the steering control sensor continues in the same direction. , when the undulation of the boundary becomes large, the steering wheels are steered at a large steering angle in order to follow the boundary with large undulation, and the size of the steering angle corresponds to the state of undulation of the boundary. becomes.

Therefore, while the vehicle body travels the first set distance, a value corresponding to the steering angle is stored each time the vehicle travels a second set distance, which is set shorter than the first set distance, or for each set time. Thus, based on the stored information, it is possible to quantitatively determine the undulation state of the boundary while traveling the first set distance.

〔Effect of the invention〕

Therefore, it is possible to quantitatively determine the undulation state of the boundary by effectively utilizing the inherent configuration of controlling the steering while increasing the steering angle according to the state of deviation from the boundary. It is now possible to accurately correct the

〔Example〕

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

As shown in Figures 8 and 9, a pair of left and right front wheels (1F
) and a pair of left and right rear wheels (1R), the lower abdomen of the vehicle body (V) is equipped with a mower (2), thereby forming a lawn mowing work vehicle used for cutting weeds, grass, etc. ing.

In addition, in the figure, (3) is a steering handle for boarding operation.

However, each of the front wheels (1F) and the rear wheels (1R) is configured in a so-called four-wheel steering type and four-wheel drive type so that it functions both as a steering wheel and a driving wheel.

As shown in Fig. 10, a section from the - side to the opposite side of the uncut land (B) as a rectangular untreated work area is regarded as one work process, and a plurality of work processes are arranged in the width direction of the vehicle body. is set, and in each work process, it automatically travels along the boundary pile between the uncut land <8) and the cut land (C) as the treated work area, and as it reaches the end of one work process, ,
The mowing work in a predetermined range is automatically performed by reciprocating each work process while repeating turns to move the lawn mower to the starting end of the next work process adjacent to that work process.

However, in this embodiment, as will be described later, the planned work area is automatically automatically started immediately from the first work process without dividing the area around the planned work area into rectangular uncut land (B) surrounded by already cut land (C). The system automatically sets the reference distance for the work process based on the distance traveled in the first work process, and each time the work vehicle travels the set standard distance, the next The robot automatically turns toward the work process.

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. Therefore, in the turn to move to the next work stroke, as the vehicle travels the reference distance, the vehicle body direction is not changed in the forward or reverse state, and after the turn is moved toward the next work stroke side, This will be done by switching between forward and backward motion.

Although the details will be described later, each time you travel through each work process,
The undulation state of the boundary (L) is determined based on the integrated value of the values corresponding to the steering angle values of the steering wheels during each work process, and if the undulation is large, the following During the work process, the linearity of the boundary (L) is corrected while automatically traveling.

Further, the work vehicle is configured so that it can be driven not only automatically but also by a boarding operation in which the work vehicle is boarded and driven manually.

As will be described later, the start and stop of automatic driving and the start of a turn in the first working process can be instructed by remote control from outside the vehicle body.

To explain the control structure of the working vehicle, as shown in FIG. 1, there is a steering hydraulic cylinder (4F) that separately operates the front and rear wheels (1F) and (1R).

(4R), their control valves (5F), (5R), a hydraulic continuously variable transmission device (6) that can freely change forward and reverse speeds, a speed change motor (7) for its speed change operation, and pre-setting memory. The control valves (5F), (5R
), a control device (8) using a microcomputer that operates the variable speed motor (7), a transmitter (9) that instructs to start or stop automatic driving, and a transmitter (9) that receives instruction information from the transmitter (9). A receiver (1) manually operated by the control device (8).
0) are provided.

Then, using the control device (8), the front and rear wheels (IP) as steering wheels, the steering control means (100) for steering the (1R), and the vehicle body (V) as the first set distance. The front and rear wheels (1F), (1R) each time the vehicle body (V) travels a second set distance that is shorter than the reference distance while traveling the reference distance of the work process.
storage means (101) for storing a value corresponding to the steering angle of;
And, based on the information stored in the storage means (101),
Waviness determining means (1) for determining the waviness of the boundary (L)
02) will be configured.

In the figure, (E) is an engine for driving the front and rear wheels (1F), (1R) and the mower (2), which is interlocked and connected to the transmission (6). (11) is a speed change arm for manually operating the speed change device (6) during boarding maneuver, and a speed change arm of the speed change device (6), The speed change motor (7) and the speed change pedal (11) can be operated by either of the pedals (11).
is linked to.

(13) is a clutch mechanism that connects and disconnects the transmission motor (7) from the transmission arm (12),
The clutch lever (14) (see FIG. 8) is manually operated to engage and disengage the clutch lever. That is, during boarding maneuvers, the clutch lever (14) is cut to disconnect the transmission motor (7) and the transmission (6), and during automatic driving, the clutch lever (14) is engaged and the transmission motor (14) is disconnected from the transmission (6).
7) and the transmission (6) are linked together.

Further, (St)I) is a clutch switch that detects the operating state of the clutch lever (14). In other words, the control device (8) determines whether the vehicle is in boarding operation or automatic driving based on the detection information of the clutch switch (SW).

By the way, as shown in FIG. 1, the front and rear wheels (1F) and (1R) are configured to function not only as driving wheels but also as steering wheels. ,
Parallel steering type that steers (1R) in the same phase,
4-wheel steering type that steers in opposite phases, front wheels (1F)
You can select from three types of steering, including a two-wheel steering type that only steers the vehicle. Although not shown, the steering type to be used is manually selected during boarding and maneuvering, and the steering type is automatically selected during automatic driving based on information detected by various sensors, which will be described later.

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

As shown in Figures 8 and 9, the position of the vehicle body (V) in the width direction with respect to the boundary (L) between the uncut land (B) and the cut land (C) is shifted to either the left or right side. A pair of left and right tracking sensors (SL) as steering control sensors to detect whether
(S2) are provided at the tips of four sensor support arms (15) that extend from both ends of the working range of the mower (2) in both the front and rear directions of the vehicle body.

Each of the copying sensors (Sυ, (S2)) includes a pair of light projecting section and light receiving section that are arranged to face each other in the width direction of the vehicle body, and the light directed from the light projecting section to the light receiving section is not yet released. The unmown land (
B) or the previously mown land) is determined.

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 of grass and the absence of grass.

Therefore, once an unmown state with grass is detected, the unmown detection state is maintained while driving a set distance.In the following explanation, the unmown detection state will be maintained. This process is referred to as copying sensor software "H" holding process.

During automatic driving, one of the four sets of scanning sensors (S1) and (S2) 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. Using one set, the vehicle body (V
) is shifted to the left or right.

However, as will be described in detail later, if it is determined that the boundary (L) has a large undulation and a process for correcting it is executed, the above 4.
set of copying sensors (Sl).

The position of the vehicle body (V) in the width direction with respect to the boundary (L) is determined by using all of the two sets on the front side with respect to the vehicle traveling direction of (S2), and the position of the vehicle body (V) in the width direction with respect to the boundary (L) is determined. (2) The state is maintained within the reaping width.

In the following description, the process of correcting the waviness of the boundary (L) will be referred to as large dead zone correction.

To explain the determination of the deviation with respect to the boundary (L), in normal driving conditions without the large dead zone scanning correction, the pair of scanning sensors (S1) and (S2) located on the boundary (L) side A state in which the tracing sensor (Sl) on the outside of the vehicle body detects the mown land (C), and the tracing sensor (S2) on the inside of the vehicle body detects the uncut land (B), It is determined that the vehicle body (V) is in a proper state with respect to the boundary (L), and both of the pair of tracing sensors (S1) and (S2) are aligned with the uncut land (B).
) is detected when the vehicle body (V) is at the boundary (L).
It is determined that there is a deviation toward the unmowed land (B) side (hereinafter referred to as deviation toward the IN side), and both of the pair of copying sensors (S1) and (S2) The state in which the mowed field (C) is detected is set to a state in which the vehicle body (V) is shifted toward the mowed field (C) side with respect to the boundary (L) (hereinafter referred to as shift toward the OUT side). It will be determined that there is.

However, as mentioned above, when performing large dead zone scanning correction processing, if all four scanning sensors on the front side in the direction of vehicle movement have shifted to the IN side from detecting the uncut ground (B). O
It will be determined that it has shifted toward the UT side.

In addition, in the following explanation, the copying sensor (3,),
(S2) is detecting the uncut land (B).
”, and the state in which the mown area (C) is detected is described as “
It is written as "L".

As shown in FIGS. 1 and 8, in order to detect the inclination of the vehicle body (V) with respect to a reference orientation set based on the length direction of the work stroke, that is, the length direction of the boundary (L), A direction sensor (S3) using a geomagnetic sensor is attached to the rear end of the vehicle body.

As shown in FIG. 1, a rotation speed sensor (S) is provided which is rotationally driven by the output of the transmission (6) and outputs a set number of pulse signals per unit rotation speed, and the rotation speed detected by the rotation speed sensor (S) is provided. The vehicle body (V) is configured to detect the traveling distance based on the vehicle body (V).

Further, a potentiometer (Ro) for detecting a target steering angle by the steering handle (3), a potentiometer (R,), (R2) for detecting the steering angle of each of the front and rear wheels (1F>, (JR>), Vehicle speed detection potentiometers (R3) are provided which indirectly detect the forward/reverse switching state as well as the vehicle speed at the time of forward/reverse loss by detecting the operating state of the transmission (6).

Next, 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 (13) is engaged and operated to link the transmission device (6) and the transmission motor (7), and the transmitter (9) is used to instruct the start of automatic driving. Become.

As the receiver (10) receives the instruction to start traveling, the control device (8) determines the orientation detected by the orientation sensor (S3), that is, the orientation of the vehicle at the time of starting traveling.
It is set and stored as the reference orientation for the first work process.

Next, after performing target steering angle setting processing to set target steering angles (θf) and (θf) for the front and rear wheels (1F) and (1R), respectively, the front and rear wheels (1F) and (1R A steering operation is performed to drive both the control valves (5F) and (5R) so that the steering angle of the direction sensor ( ) becomes the set target steering angle (θf), (θf). After making sure that the direction detected by S3) is maintained within the set dead zone with respect to the reference direction, the vehicle speed is operated to operate the speed change motor (7) so that the vehicle speed becomes the set vehicle speed, and the vehicle speed is changed to the forward state or The vehicle will start traveling in reverse.

Note that the target steering angles (θf) and (θf) are respectively set when the front and rear wheels (1F) and (1R) are rotated to the right with respect to a value corresponding to a neutral steering position corresponding to a state in which the vehicle is running straight. A positive value is set for steering, and a negative value is set for leftward steering.

In other words, as mentioned above, the planned work area is a rectangular uncut area (
B) If work is started without dividing the area into sections, the boundary (L) between the uncut land (B) and the cut land (C) is not formed in the first work process (first process). for,
Since it is not possible to determine the deviation in the vehicle width direction with respect to the boundary (L) using the detection information of the copying sensors (S1) and (S2), in the first step, only the detection information of the direction sensor (S3) is used. It uses this to make the vehicle run automatically.

However, as shown in Fig. 10, in each work step after the first step, as the mower (2) progresses in the reaping work, the uncut land (B) and the cut land (C) are separated. boundary (L
) is formed, so that it automatically moves in the direction of each work process while avoiding leaving uncut areas.
the direction sensor (S3) and the copying sensor (s+),
Steering control is performed using both of the detection information in (S2).

Therefore, the process of determining the undulation of the boundary (L) and correcting the large dead zone based on the determination result is not performed in the first step.

After the start of travel, it is determined whether or not a turn start instruction has been received based on the information received by the receiver (10) in the first stroke, and as the turn start instruction is received, the rotation speed is increased. The distance traveled from the start point detected by the sensor (S) to the time when the turn start instruction is received is calculated as follows:
After setting and storing the reference distance for each subsequent work stroke, turn control for moving to the next work stroke is started.

After turning for the next work stroke, the traveling distance detected by the rotation speed sensor (S) reaches the set and memorized reference distance, or the receiver (10) starts working. As described above, the copying sensor (S1
), (S2) and the direction sensor (S3).

When the distance traveled reaches the reference distance, the boundary (
After performing the undulation determination process to determine the undulation state of L), it will be turned for the next work process.
When the instruction to end the work is received, the vehicle stops traveling and ends the work.

To explain the steering control, basically, when the direction detected by the direction sensor (S) deviates from the reference direction, the four-wheel steering system is used to steer the vehicle body (V). and correct the orientation of the scanning sensor (S
1), the boundary (L) based on the detection information of (S2)
If it is determined that the vehicle has deviated from the boundary (L), the front and rear wheels (1F) and (1R) are steered in the same phase using the parallel steering method to correct the position in the width direction with respect to the boundary (L). It turns out.

In addition, when correcting the position of the vehicle body (V) with respect to the boundary (L) using this parallel steering method, the steering angle is increased by a set amount as long as the detected deviation direction continues in the same direction. It is intended to be directed towards the future.

However, if both the orientation of the vehicle body (V) with respect to the reference direction and the position in the width direction with respect to the boundary (L) are deviated, the target ff In the heading angle setting process, the front and rear wheels (1F) are automatically set.

This is done so that the target steering angles (θf) and (θf) of (1R) are different.

Further, in the case where it is determined in the undulation determination process that the undulation at the boundary (L) is large, automatic travel is performed based on the detection information of only the azimuth sensor (S3) in the first step. In the same manner as above, the scanning sensor (S
1), the boundary (L) is automatically driven without using the discrimination information of the deviation with respect to the boundary (L) according to (S2).
This will correct the undulations. In addition, when correcting this undulation, the front and rear wheels (1F) and (1R) are steered in the same direction with different steering angles.

However, even when performing this process to correct the undulation, in order to prevent uncut areas, the four scanning sensors on the front side of the vehicle are used as described above, and all four scanning sensors are set to When mowed land (B) or already mowed land (C) is detected,
The object is forced to move in parallel by steering at a set steering angle in a direction opposite to the direction of detection.

Further, processing such as detecting the traveling distance by the rotation speed sensor (S4) and determining information detected by the copying sensors (S1) and (S2) is automatically started every time the vehicle travels a set distance (5 cm). It is designed to be executed as interrupt processing.

To explain the turn control, as mentioned above,
Since the vehicle body (V) is designed to repeatedly move forward and backward and travel back and forth during each work process, the parallel steering type is used, for example, by traveling a set distance at the maximum turning angle, the next work is performed. After moving it closer to the stroke side, it will switch between forward and backward movement.

Each process will be explained in detail below.

First, the interrupt processing will be explained based on the flowchart shown in FIG.

In other words, as mentioned above, this interrupt processing is performed at the set distance (
5cm) will be activated every time you run, and
Based on the detection information of the rotation speed sensor (S4), after counting the cumulative travel distance after the start of travel in each work stroke, it is determined whether or not the first stroke is being traveled.

If it is not the first stroke, the two sets of copying sensors (Sl) are on the front side with respect to the vehicle traveling direction.

(S2) Read each detection data and as mentioned above,
The scanning sensor (Sυ, (S2)
After detecting B), the scanning sensor software performs "H" holding processing to hold "H" corresponding to the uncut detection state while traveling the set distance after that, and then, based on the processed data, the boundary is If there is undulation in (L), a scanning sensor processing data discrimination process is performed to correct the undulation.

Next, a steering angle integration process is performed in which a value corresponding to the target steering angle (θn) for tracing set in the target steering angle setting process described later is integrated every time the set distance (5 cm) is traveled. .

To explain, if the target steering angle (θn) is not 0, which corresponds to a straight-ahead state, the value obtained by subtracting 1 from the absolute value of that value is integrated as the value corresponding to the steering angle. ing.

In other words, if the deviation with respect to the boundary (L) cannot be corrected while the target steering angle (θn) remains small, the steering will be performed until the angle becomes larger sequentially, so that the waviness of the boundary (L) is reduced. The larger the value, the larger the integrated value becomes.

Therefore, this steering angle integration process is performed when the vehicle body (V) is in the first position.
While traveling the reference distance as the set distance,
The target steering angle for copying (
This corresponds to the storage means (Lot) that stores the value corresponding to θn).

Therefore, as shown in FIG. 4, in the undulation determination process that is executed each time the travel distance reaches the reference distance, the steering angle integrated value that is executed in the interrupt process is The magnitude of the steering angle per unit traveling distance is determined by dividing by the number of times the interrupt process has been activated.

Then, it is determined whether the division value is greater than or equal to a preset value corresponding to a state in which the undulation is large, and if the division value is greater than or equal to the preset value, the undulation of the boundary (L) is determined. is determined to be large, and a flag is set to execute the large dead zone correction process in order to correct the waviness, and if the division value is less than the set value, the boundary It is determined that the undulation of (L) is small, and the flag is reset.

In other words, this undulation determination processing is performed by the storage means (10
1) This corresponds to the undulation determination means (102) that determines the undulation of the boundary (L) based on the stored information stored in the steering angle integration process as shown in FIG.

It should be noted that the flag for executing the large dead zone scanning correction process is set in the scanning sensor processing data determination executed in the interrupt processing and in each process of target steering angle setting described later, whether it is a normal work process or not. This will be used as information for determining whether or not the work process is for large dead zone correction to correct the waviness of the boundary (L).

To explain the scanning sensor processing data discrimination process, as shown in FIG. 5, it is determined whether or not to perform the large dead zone scanning correction based on the state of the flag set in the waviness discrimination process. , when performing a large dead zone tracing correction, - determines whether or not the correction is in progress.

If the modification is in progress, the value of the modification counter for monitoring the progress of the modification process is decremented, and then it is determined whether the value has reached O or not.

When the value of the counter during correction has reached D, the IN flag for steering the vehicle body (V) toward the unmoved area (B) and the mown area (C )
Reset each of the OUT flags for steering to the side.

After resetting each of the IN flag and the UT flag, or when it is determined that the large dead zone scanning correction is not in progress, all four scanning sensors on the front side in the direction of movement are set to the uncut position. It is determined whether the ground (B) or the mown ground (C) is detected.

When all of the four tracing sensors detect the mowed land (C), the traveling direction of the vehicle body (V) is set to the unmoved land (C).
In order to make the correction to the B) side, after setting the IN flag and resetting the OUT flag, the value of the correction counter is set to 100, which corresponds to the set distance (5 m).

In other words, this scanning sensor processing data discrimination processing is performed in 5 c
Since this is executed in an interrupt process that is activated every time the vehicle travels m, the value of the correction counter is set to 100, which corresponds to 5 m.

On the other hand, when all of the four tracing sensors detect the unmoved area (B), the IN After resetting the flag and setting the OUT flag, the value of the modifying counter is set to 100.

In addition, if all of the four copying sensors are not in a state where they are detecting the uncut area (B) or the cut area (C), the setting of the IN flag and OUT flag and the setting of the correction counter Please refrain from doing so.

After setting the IN flag and OUT flag and setting the correction counter, the scanning sensor data setting process is performed to set the scanning sensor data in order to determine the state of deviation with respect to the boundary (L). This will end the interrupt processing.

Next, the target steering angle setting process will be explained based on the flowcharts shown in FIGS. 6(a) and 6(b).

As shown in FIG. 6(a), first, the direction sensor (S
The detected orientation according to 3) is read, the current orientation is calculated, and the deviation (Δθ) between the current orientation and the reference orientation is calculated.

Next, the deviation (Δθ) is set in a preset dead zone (±2
Based on whether or not the orientation of the vehicle body (V) is within the range of 150° to Target steering angles (θhf) and (θhr) for direction correction for wheels (1F) and (1R) are set to preset values (±5 degrees) so that the signs are opposite and the values are the same. settings so that the front and rear wheels (1F) and (1R) are steered in a four-wheel steering style.

However, the IN flag or ○UT for the large dead zone copy correction
Based on whether or not the flag is set, it is determined whether or not the correction is to follow the large dead zone. If the correction is to follow the large dead zone, as described above, the front and rear wheels (1F ).

Target steering angle (θhf) of (1R), (θhr) is 5
This is done to differentiate degrees.

Furthermore, even when no azimuth correction is required, if the correction is based on the large dead zone, the target steering angle (θhf) for the azimuth correction is determined according to the correction direction.

(θhr) are set to have the same sign and the same value (5 degrees) so that the vehicle body (V) moves in parallel in the correction direction.

That is, the target steering angle (θhf) for the direction correction.

By setting (θhr) to have the same sign and the same value (5 degrees), while the vehicle body (V) travels the set distance (5 m), half of the cutting width of the mower (2) is translated in parallel. That's what I'm trying to do.

On the other hand, if the direction is not corrected and the large dead zone is not corrected, the target steering angle for the direction correction (θhf),
After setting (θhr) to 0, it is determined whether or not the vehicle is traveling in the first stroke and whether or not it is a stroke in which the large dead zone tracing correction is performed.

When traveling in the first stroke or when performing large dead zone scanning correction, the scanning control using the scanning sensors (S1), (S,) on the boundary (L) side is not performed. After setting the value of the target steering angle (θn) for copying to 0, the target steering angle (θhf), (θh
r) and the target steering angle for copying (θn) to set the target steering angles (θr) and (θr) for the front and rear wheels (1F) and (1R), respectively. (See Figures 6 (a) and (b)).

On the other hand, if the travel is not in the first stroke or the stroke in which the large dead zone scanning correction is performed, as shown in FIG. The scanning sensor data on the set boundary side is read and the scanning correction direction is determined.

When performing tracing correction, it is based on whether the boundary (L) is located on the left or right side of the vehicle body (V) and the direction of travel depending on whether the vehicle is traveling forward or backward. , the upper limit value (
After setting θno) to the preset values (±θn1N) + (±θnout) corresponding to the IN side and the oUT side, the target steering angle (θn
) is increased by the set amount n (
The casing of d) is set to preset values (d+N) and (dour) corresponding to the IN side and OUT side, respectively.

Next, as shown in FIG. 6 (+2), based on the sign of the upper limit value (θno) of the target steering angle (θn) for the copying correction, the copying correction direction is set to the left or right with respect to the vehicle body (V). and, depending on the determined direction, determine whether the target steering angle (θn) is between 0 degrees, which corresponds to straight-ahead travel, and the upper limit value (θno). By determining
It is determined whether the position of the vehicle body (V) relative to the boundary (L) has shifted in the opposite direction.

The target steering angle (θn) is 0 degrees and the upper limit value (θno)
In other words, if the positional deviation in the width direction of the vehicle body with respect to the boundary (L) continues in the same direction, the set distance (d) is set so that the vehicle body position can be quickly corrected. Each time the vehicle travels, the target steering angle (θn) is increased by a set amount (1 degree), and after clearing the mileage count for determining whether or not the vehicle has traveled the set distance (d), a target steering angle (θhf) for the azimuth;

(θhr) and the target steering angle for copying (θn) to set the target steering angles (θf) and (θf) for the front and rear wheels (1F) and (1R), respectively. .

However, if the position of the vehicle body (V) with respect to the boundary (L) shifts in the opposite direction to the left and right, and the sign of the target steering angle (θn) is reversed with respect to the previous setting state, the vehicle body (V)
) is in the opposite direction to the boundary (L) (in order to avoid oversizing, the target steering angle (θn
) is set to return to 0 degrees.

If the copying correction is not necessary, it is determined whether the target steering angle (θn) for copying is set to 0 degrees or not, and if it is not 0 degrees, the set distance (d,) is determined. The target running angle (θn
) after decreasing the set angle (1 degree), the mileage count is cleared (see Figure 6 (b)).

In other words, if the position in the width direction with respect to the boundary (L) deviates, the target steering angle (θn) for copying to correct the deviation is initially set to a small value, and If the correction cannot be made, the target steering angle (θn) is increased by the set amount for each set distance (d), and when the deviation has been corrected, the target steering angle (θn) is increased by the set amount for each set distance (d,). This will prevent the vehicle body from moving too quickly, and if there is a large deviation, it will be corrected without delay, and if the deviation is small, the meandering of the mowing mark, i.e. the boundary (L) above, will be corrected. This is to make the undulations as small as possible.

To explain the steering operation, as shown in FIG. 7, the steering angle detection potentiometer (R1), (R
2) Detect the steering angles of the front and rear wheels respectively, and calculate the detected steering angles and the target steering angle (θf).

The steering control valves (5F) and (5R) are driven or You will have to perform a stop operation.

Accordingly, the target steering angle setting process of setting the target steering angles (θf), (θf) of the front and rear wheels (1F), (1R), and the turning angle of the front and rear wheels (1F), (1R) are performed. A steering operation process for operating the steering control valves (5F) and (5R) so as to achieve the set target steering angles (θf) and (θf) is performed in the steering control means (100). We will deal with it.

[Another example]

In the above embodiment, while the direction of deviation detected by the scanning sensors (s1) and (S2) as steering control sensors continues in the same direction, the scanning is performed every time the vehicle body (V) travels the set distance (d). Although a case has been exemplified in which the correction target steering angle (θn) is increased by a set amount, it may be increased by a set amount at every set time.

Furthermore, in the above embodiment, when the direction is corrected, the target steering angles (θhf) and (θhr) are set to constant setting angles, but the detected direction relative to the reference direction is It may be set according to the magnitude of the deviation (Δθ).

Further, in the above embodiment, the direction correction is performed using a four-wheel steering system, but it may also be performed using a two-wheel steering system.

Further, in the above embodiment, the steering control is performed while also correcting the heading, but the steering control may be performed without correcting the heading. However, in that case, the following correction may be performed by, for example, steering only the front wheels (1F) or the rear wheels (1R) that are on the front side with respect to the vehicle traveling direction.

In addition, in the above embodiment, the target steering angle (θn) for copy correction
In the above example, the magnitude of the undulation is determined based on the integrated value of the values corresponding to the values of the front and rear wheels (
Based on the cutting angle of 1F) and (1R), if the cutting angle is large, it is determined that there is a undulation, or,
The standard deviation or the like may be calculated based on a histogram of target steering angle or turning angle values for each set distance or set time while traveling the reference distance.

Furthermore, in the above embodiment, when it is determined that the undulation of the boundary (L) is large, the correction is automatically performed. However, for example, if the undulation of the boundary (L) is If it is determined that the swell is large, a warning may be issued and the swell may be corrected by the on-board maneuver. Various changes can be made.

Further, in the above embodiment, the present invention is applied to a lawn mowing work vehicle, and the start and stop of automatic travel is instructed by remote control, and the vehicle is repeatedly driven forward and backward to travel back and forth. , the surroundings of the work area can be formed in advance into a mown area (C), and the reference direction, reference distance, number of work strokes, etc. can be set in advance and the robot can travel automatically, or it can be used for reciprocating travel by reversing the travel direction by 180 degrees. The vehicle may be run in a so-called roundabout mode, and the mode of automatic travel and the specific configuration of each part for automatic travel may 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 a working vehicle with a steering control device according to the present invention, in which Fig. 1 is a block diagram of the control configuration, Fig. 2 is a flowchart of automatic driving, Fig. 3 is a flowchart of interrupt processing, and Fig. 4. is a flowchart of the undulation discrimination process, FIG. 5 is a flowchart of the scanning sensor processing data discrimination process, FIGS. 6(a) and (a) are a flowchart of the target steering angle setting process, and FIG. 7 is a flowchart of the steering operation process. , Figure 8 is an overall side view of the working vehicle, Figure 9 is a plan view of the same, and Figure 10 is a side view of the working vehicle.
The figure is an explanatory diagram of the work area, and FIG. 11 is an explanatory diagram of the undulation of the boundary. (V)... Vehicle body, (B)... Untreated work area, (C)... Treated work area, (L)...
... Boundary, (s+), (S2) ... Steering control sensor, (θn) ... Steering angle, (1F),
(1R)...Steering wheel, (100)...
- Steering control means, (101)... Storage means, (
102)...Waviness determination means.

Claims (1)

[Claims] 1. The position in the width direction of the vehicle body (V) is an untreated work area (B)
A steering control sensor (S
_1), (S_2) and its steering control sensor (S_1)
), based on the detection information of (S_2), the steering wheel (1F)
, (1R) in a direction to correct the deviation with respect to the boundary (L), and the steering control means (100) is configured to control the steering control sensor. While the detection deviation direction by (S_1) and (S_2) continues in the same direction, each time the vehicle body (V) travels a set distance or every set time, the steering wheels (1F) and (1R) are The work vehicle is equipped with a steering control device configured to increase the steering angle (θ_n) by a set amount in order to steer the vehicle, and while the vehicle body (V) travels a first set distance, the Storage means (10
1) and a waviness determining means (101) for determining the waviness of the boundary (L) based on the information stored in the storage means (101).
102) A work vehicle equipped with a steering control device. 2. The storage means (101) stores the steering angle (θ_n)
2. The work vehicle with a steering control device according to claim 1, wherein the work vehicle is configured to store an integrated value set such that the value increases as the value increases.