JPH0366682B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a tracing sensor that detects a predetermined boundary between a working area and a non-working area in a driving area, and a control device that controls a vehicle body to automatically run along the detected boundary. The present invention relates to a traveling vehicle equipped with a tracing sensor.

Conventionally, in this type of traveling vehicle equipped with a tracing sensor, a sensor is installed in the vehicle body to detect the boundary of the traveling area, and the steering wheel is automatically steered by a certain amount in a predetermined direction based on the boundary detection result of this sensor. Tracing travel control has been performed to automatically travel along this boundary.

However, in the conventional example, it was possible to detect whether the vehicle body crossed the boundary in an ON/OFF manner, but it was not possible to detect the angle of approach.

Therefore, when approaching a boundary of the vehicle body, the vehicle body is steered in the opposite direction with a constant steering amount regardless of the approach angle, and when the boundary is detected again, the vehicle body is steered in the opposite direction, and so on. The steering was controlled to make the vehicle move.

Therefore, when approaching the boundary of the vehicle body, depending on the angle, the steering wheel may be steered more than necessary and turn too much, making it impossible to properly align the vehicle body with the boundary, and steering operation in the opposite direction may be impossible. It is easy to cause the so-called hunting phenomenon, which is said to repeat permanently, and for this reason, in particular,
Lawn mowing vehicles equipped with tracing sensors have the disadvantage that the mowing marks are undulating, detracting from the aesthetic appearance, which is a serious problem.

Therefore, we detect the approach angle of the vehicle body to the boundary of the running area by using a tracing sensor consisting of two sensors installed in parallel in the left and right direction of the vehicle body, which is originally equipped for tracing control. It is conceivable to steer the steering wheels by a predetermined amount based on the approach angle, but in such a configuration, if the vehicle approach angle to the boundary is large, the time interval between the two sensors detecting the boundary, and the time interval between them. Because the distance between the vehicle body movements is short, not only is sufficient accuracy not achieved, but if the vehicle enters the boundary at a nearly right angle, the angle cannot be detected, resulting in malfunctions.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to enable detection of the approach angle with sufficient accuracy no matter what approach angle the vehicle body approaches the boundary, and to detect the approach angle with sufficient accuracy. To provide a traveling vehicle with a tracing sensor capable of quickly moving a vehicle body to a tracing state along a boundary by performing steering control according to a detected approach angle.

In order to achieve the above object, a traveling vehicle with a copying sensor according to the present invention has the above-mentioned structure, and has the following features: [a] The copying sensor has two parts that detect whether the copying sensor is a working area or a non-working area at an installation position. sensor,
Another sensor is installed at a predetermined interval in the left and right direction in front of the vehicle body, and another sensor is installed to detect whether the installation location is a working area or a non-working area. It is arranged diagonally in front of the

[B] A distance sensor is provided to detect the distance traveled by the vehicle body.

[C] The control device issues a following driving command to the steering drive mechanism to align the vehicle body along the boundary based on the detection results of the boundary between the working area and the non-working area by the two sensors. have the means.

[d] The control device starts measurement based on the boundary detection output of the other sensor, and ends the measurement based on the boundary detection output of the sensor on the inside of the vehicle body, based on the detected travel distance of the distance sensor. The approach angle with respect to the boundary of the vehicle body is determined by the mounting interval of the other sensor with respect to the sensor on the inside of the vehicle body among the two sensors, and the mounting angle of the other sensor with respect to the direction in which the two sensors are arranged side by side. The approach angle calculating means is provided for calculating the angle of approach based on the following equation θ=tan ⁻¹ (d ₂ ·sin θ ₀ /(x−d ₂ ·cos θ ₀ )).

[E] The control device steers the front wheels in a predetermined direction in accordance with the calculated approach angle,
It is provided with approach direction control means that instructs switching after a predetermined period of time has elapsed.

The characteristic configuration includes the configurations described in [A] to [E] above.

The functions and effects of this characteristic configuration are as follows.

In other words, although it has an extremely simple configuration of two sensors installed side by side along the left and right directions that are originally provided as a copying sensor, and another sensor is added diagonally in front, , one sensor located diagonally forward will enter the boundary before the two sensors, regardless of the size of the approach angle, and it will be able to sufficiently detect the travel distance required to calculate the vehicle's approach angle. Therefore, the approach angle can be calculated with sufficient accuracy based on the detection result.

Therefore, even with a simple structure, it has become possible to accurately calculate the approach angle of the vehicle body to the boundary, and to make the vehicle follow the boundary with the minimum amount of steering control corresponding to the approach angle.

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a lawn mowing device 4 is suspended between the front and rear wheels 2 and 3 of the vehicle body 1 so as to be movable up and down, and an unmowed lawn that is the boundary between the running areas is connected to the front of the vehicle body 1. Tracing sensors A, A, which will be described later, are provided on the front left and right sides of the vehicle body 1, respectively, for determining the boundary with the already mown field, thereby configuring a lawn mowing vehicle as a traveling vehicle with tracing sensors.

Furthermore, a fifth distance sensor 5 is installed in the vehicle body 1 and generates one pulse per unit traveling distance K to continuously detect the moving distance of the vehicle body 1.
A ring has been set up.

The front wheels 2, 2 are configured as steering wheels to be steered by a predetermined amount in the left-right direction by a hydraulic cylinder 6 based on the boundary detection result of the copying sensor A.

As _shown in _{FIG .}
The light emitting elements P ₁ are fixed to the sensor mounting frame 8 provided on the lawn mower 4 with d _{1 and} d 2 separated from each other, and light emitting elements P ₁ are respectively provided on the inner facing surfaces of the sensor frames 7 .
and a light-receiving element _P2 are provided as a pair, and by sensing the presence or absence of grass introduced as the vehicle body 1 travels between the light-emitting element _P1 and the light-receiving element _P2 , it is possible to determine whether or not the grass is unmoved. It is configured to determine the boundary between the ground and the mowed land.

Furthermore, as shown in FIG.
Sensors S ₂ and S ₃ are arranged with a mounting interval d ₁ apart in the left-right direction of the vehicle body 1, and sensors S ₂ and S 3 are arranged diagonally forward of the sensors S 2 and S ₃ with a mounting interval d ₂ apart, and toward the inside of the vehicle body 1. One sensor S ₁ , which can detect the presence or absence of grass in the same way as the sensors S ₂ and S ₃ , is attached to the mounting frame 8 at a position inclined at a predetermined angle θ _0.
It is fixed to. Here, as a result of an experiment, the predetermined angle θ ₀ is
Approximately 160 in order to accurately detect the vehicle body approach angle θ
Although the degree is suitable, other angles may be used and may be selected as appropriate depending on the configuration of the vehicle body 1, that is, the vehicle configuration, work speed, etc. Note that the sensor A is not limited to one using the optical sensors S ₁ , S ₂ , and S ₃ , and may be configured using any type of sensor, whether contact type or non-contact type.

FIG. 3 shows the determination of the vehicle body approach angle θ to the boundary based on the detection result of the boundary between the unmown field and the mowed field by the scanning sensor A configured as described above, and the determination of the vehicle body approach angle θ to the boundary.
1 shows a block diagram of a control device 9 configured to steer the front wheels 2, 2 with a steering amount corresponding to .

The control device 9 includes an I/O port 10, a CPU
11, a memory 12, and a counter 13. Then, the control device 9
Optical sensors S ₁ and S ₂ forming the scanning sensor A
The approach angle θ to the boundary is determined based on the time difference between turning ON and the vehicle body movement distance x during that time, and
An electromagnetic valve 1 is installed in the hydraulic circuit of the hydraulic cylinder 6 to steer the front wheels 2, 2 in a predetermined direction with a steering amount corresponding to this approach angle θ.
4 is driven through a buffer circuit 15.

In addition, 16 is a hydraulic pump, and this hydraulic pump 16, the front wheel 2, the hydraulic cylinder 6, and the electromagnetic valve 1
4 and the buffer circuit 15 constitute a steering drive mechanism. Therefore, the control device 9 includes optical sensors S ₂ , which are arranged in parallel with a predetermined mounting interval d ₁ .
Tracing operation in which the steering drive mechanism is commanded to align the vehicle body 1 along the boundary based on the detection result of the boundary between the unmoved land as a working area and the mowed land as a non-working area by _S3 . In addition to being equipped with a command means,
an approach angle calculating means for calculating an approach angle θ to the boundary of the vehicle body 1 based on the vehicle body moving distance X, the mounting interval d ₂ and the angle θ ₀ ; Correspondingly, the vehicle is provided with approach direction control means for instructing to steer the front wheels 2 in a predetermined direction and then to switch after a certain period of time has elapsed.

Hereinafter, the means for determining the approach angle θ to the boundary will be explained based on the conceptual diagrams for detecting the approach angle θ shown in FIGS. 4A and 4B.

That is, when the vehicle body 1 enters from a mowed field toward an unmown field at an angle of approach θ diagonally in the direction of the arrow shown at the boundary, the sensor S ₁ first detects the unmown land and turns ON.
do. Then, as the vehicle body 1 moves,
If the approach angle θ is small, as shown in Figure 4 (A), and if the approach angle θ is large, as shown in Figure 4 (B), the sensor S ₂ will detect the uncut ground in either case. Turn on.

Then, after the sensor S ₁ is turned on, the sensor S ₂ is turned on.
The counter 13 counts the number of pulses output from the distance sensor 5 during the ON period,
Based on this count value n and the unit traveling distance K, the moving distance x during this time is calculated as x=K·n.

Then, this moving distance x and the optical sensor S ₁ ,
The approach angle θ is based on the mounting distance d ₂ of S ₂ and the mounting angle θ ₀ .
is calculated based on the following formula ().

θ=tan ^-1 l ₂ /x−l ₁ ...() (However, l ₁ = d ₂ · sin θ ₀ , l ₂ = d ₂ · cos θ ₀ ), so both l ₁ and l ₂ are constants. be. ) Then, the hydraulic cylinder 6 is driven to obtain a steering angle corresponding to this approach angle θ, and the front wheels 2, 2 are steered to the right by a predetermined amount, and after a predetermined time, the front wheels are reversely steered to the left. It is controlled to follow the boundary with minimal steering. After controlling the running direction to follow the boundary in this way, the optical sensor S ₂ ,
Normal scanning control is performed so that S ₃ continuously detects the boundaries between unmoved fields and mowed fields, so that the vehicle body 1 can be properly aligned with the boundaries regardless of the magnitude of the approach angle θ. After that, automatic tracing control was successfully performed.

FIG. 5 is a flowchart showing the routine of the above-mentioned control device 9 upon entry. As shown in the figure, when this routine is completed, normal scanning control using sensors S ₂ and S ₃ is started.

In addition, in the flowchart of Figure 5,
WAIT means that the steering control is placed in a standby state until a reverse steering operation is started after the steering has been performed by a predetermined amount.

In addition, in the approach routine described above, which side of the left and right scanning sensors A is used depends on which side of the vehicle body the uncut land is located on. , the selection and switching of both sensors A and A may be performed manually,
Alternatively, the detection may be performed automatically by separately providing a sensor for detecting the position of the unmowed land.

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 drawings]

The drawings show an embodiment of a traveling vehicle with a copying sensor according to the present invention, in which FIG. 1 is an overall plan view, FIG. 2A is a front view of the copying sensor, and FIG. 2B is a schematic plan view showing its arrangement. Figure 3 is a block diagram of the control device.
Figure 4 A and B are conceptual diagrams of approach angle detection, and Figure 5
The figure is a flowchart showing the operation of the control device. 1...Vehicle body, 2...Front wheel, 5...Distance sensor, A...Copying sensor, _S1 , _{S2, S3} ...Sensor, _d1 ...Predetermined interval, _d2 ...Mounting interval, x... ...Traveling distance, θ ₀ ...Installation angle, θ...Approach angle.

Claims (1)

[Scope of Claims] 1. A tracing sensor A that detects a predetermined boundary between a working area and a non-working area in a driving area, and a control device 9 that controls the vehicle body 1 to automatically run along the detected boundary. A traveling vehicle equipped with a copying sensor, wherein the copying sensor A includes two sensors that detect whether the installation location is a working area or a non-working area.
S ₂ and S ₃ are arranged side by side at a predetermined interval d ₁ in the left and right direction in front of the vehicle body 1, and another sensor S ₁ for detecting whether the installation position is a working area or a non-working area is installed in the front of the vehicle body 1. Two sensors S ₂ ,
It is configured to be installed diagonally in front of the sensor S ₂ on the inside of the vehicle body from the sensor S ₃ on the inside of the vehicle body. [B] A distance sensor 5 for detecting the moving distance X of the vehicle body 1 is provided. [C] The control device 9 controls the two sensors.
Based on the detection result of the boundary between the working area and the non-working area by S ₂ and S ₃ , a following driving command means is provided which instructs the steering drive mechanism to align the vehicle body 1 along the boundary. [d] The control device 9 starts the measurement based on the boundary detection output of the other sensor S ₁ , and starts the measurement based on the boundary detection output of the sensor S ₂ on the inside of the vehicle body among the two sensors S ₂ and S ₃ . the detected moving distance X of the distance sensor 5 to end;
Of the two sensors S ₂ and S ₃ , the other sensor for the sensor S ₂ on the inside of the vehicle body.
Mounting interval d ₂ of S ₁ and its other sensor
The approach angle θ with respect to the boundary of the vehicle body ₁ is determined by the mounting angle θ ₀ of S ₁ with respect to the direction in which the two sensors S ₂ and S ₃ ^are arranged side by _side . The vehicle is equipped with approach angle calculation means for calculating based on x-d ₂ ·cos θ ₀ )). [E] The control device 9 includes approach direction control means for steering the front wheels 2 in a predetermined direction in accordance with the calculated approach angle θ, and instructing the steering to be switched after a certain period of time has passed. A traveling vehicle with a tracing sensor characterized by having the configuration described in [A] to [E] above.