JPH0323925B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a traveling vehicle equipped with a tracing sensor, and more particularly, a tracing sensor that detects a predetermined boundary of a traveling area, and a control that controls the vehicle to automatically travel along the detected boundary. The present invention relates to a traveling vehicle equipped with a tracing sensor.

In this type of vehicle equipped with a tracing sensor,
After the vehicle enters the predetermined boundary of the driving area,
When the scanning sensor detects a predetermined boundary and shifts to a state in which automatic driving is possible, if the steering operation is started from the moment the vehicle enters the boundary, there will be differences in the so-called inner wheel difference, outer wheel difference, and control response time. As a result, as shown by the dotted line in FIG. 5, depending on the angle at which the vehicle body 1 approaches the boundary, the vehicle body 1 may protrude outside the boundary by approximately one-half of the vehicle body width.

Therefore, in order to solve the above drawbacks, conventionally,
By controlling the steering amount from the point when the vehicle enters the boundary so that it gradually increases, and by controlling the steering amount so that it does not use a large steering amount from the beginning of the steering, it is possible to prevent the vehicle from protruding from the boundary. However, this conventional means has the disadvantage that the steering amount is finely controlled, making the control complicated and requiring a large burden in designing the control procedure.

The present invention was developed in view of the above-mentioned circumstances, and uses simple steering control to enable the tracking sensor to detect the boundary regardless of the approach angle at which the vehicle approaches the boundary. The purpose of the present invention is to provide a traveling vehicle equipped with a tracing sensor that allows the vehicle body to follow the vehicle.

In order to achieve the above object, the traveling vehicle with a tracing sensor according to the present invention is provided with: (a) means for detecting the approach angle and approach start timing of the vehicle body with respect to the boundary;

[B] The control device includes steering condition setting means for setting a predetermined time and a steering amount corresponding to the detected approach angle.

[C] The control device is configured to steer the front wheels in a predetermined direction with a steering amount corresponding to the approach angle after the preset predetermined time has elapsed from the approach start time, and then commands to switch after a predetermined time elapses. Equipped with directional control means.

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

The effects of this characteristic configuration are as follows.

In other words, when approaching the boundary of the vehicle body, by performing steering to align the vehicle body with the boundary after a predetermined time delay from the point of time when the vehicle body approaches the boundary, the steering wheel can be adjusted at the point when the vehicle body has entered the boundary to a certain extent. This will be the first time you will be steering the vehicle, and even if you use a predetermined amount of steering, you will be steering from a position that is a certain distance from the boundary, so the vehicle body will not protrude beyond the boundary to the point that it cannot follow the boundary after steering, which is different from the conventional method. As such, complicated control such as gradually changing the steering amount is no longer necessary, and the control means can be made extremely simple, reducing the burden on the design of the control means.

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, 3 of a vehicle body 1 so as to be movable up and down, and an unmowed lawn and an already mowed field, which is the boundary of the running area, are placed in front of the vehicle body 1. A lawn mowing vehicle as a traveling vehicle with a scanning sensor is constructed by providing scanning sensors A and A of the configuration described later on the front left and right sides of the vehicle body 1, respectively, for determining the boundary with the mowed field.

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.

Then, as shown in Figure 2B, the sensor
Sensors S ₂ and S ₃ are arranged at a mounting interval d ₁ in the left-right direction of the vehicle body 1, and are mounted diagonally forward of the sensors S ₂ and S ₃ at a mounting interval d ₂ and at a predetermined distance from the inside of the vehicle body 1. It is fixed to the mounting frame 8 so as to be placed at an inclined position at an angle θ ₀ .

Here, the predetermined angle θ ₀ was found to be approximately 160 degrees as a result of experiments in order to accurately detect the vehicle body approach angle θ in the lawn mowing vehicle shown in the example. The angle may be selected as appropriate depending on the configuration of the vehicle body 1, that is, the vehicle configuration, work speed, etc.

In addition, as the sensor A, the optical sensor S ₁ ,
It is not limited to those using S ₂ and S ₃ , and may be configured using any type of sensor, including contact type and non-contact type.

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

The control device 9 includes an I/0 port 10, a CPU
11, a memory 12, and a counter 13.

Then, based on the time difference between the ON times of the optical sensors S ₁ and S ₂ constituting the scanning sensor A and the vehicle body movement distance x during that time, the approach angle θ to the boundary is determined, and the approach angle θ corresponding to this approach angle θ is determined. An electromagnetic valve 14 installed in the hydraulic circuit of the hydraulic cylinder 6 is driven via a buffer circuit 15 in order to steer the front wheels 2, 2 in a predetermined direction by the amount of steering.

In other words, the optical sensors S ₁ and S ₂ of copying sensor A
, the distance sensor 5, and the control device 9 constitute means for detecting the approach angle θ, and
The optical sensor S ₁ and the control device 9 constitute means for detecting the start timing of the approach of the vehicle body 1 to the boundary, and the control device 9 detects a predetermined time period corresponding to the detected approach angle θ, as described later. comprising a steering condition setting means for setting T and a steering amount, and
Approach direction control means for instructing to steer the front wheels 2 in a predetermined direction with a steering amount corresponding to the approach angle θ after the predetermined time T has elapsed from the detected approach start time, and then to switch after a predetermined time has elapsed. It is configured.

Hereinafter, the procedure 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 the boundary from a mowed field toward an unmown field obliquely in the direction of the arrow shown in the figure at an approach angle θ, the sensor S ₁ first detects the unmown land and
Turn on. Thereafter, as the vehicle body 1 moves, if the approach angle θ is small, as shown in FIG. 4A, and if the approach angle θ is large, as shown in FIG. Sensor S ₂ detects unmowed land and turns 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 ,
Based on the mounting interval d ₂ of S ₂ and the mounting angle θ ₀ , the approach angle θ is calculated based on the following formula ().

θ=tan ^-1 l ₂ /x−l ₁ ...() (However, since l ₁ = d ₂・sinθ ₀ and l ₂ = d ₂・|cosθ ₀ |, both l ₁ and l ₂ are constants. ) Then, the hydraulic cylinder 6 is driven to steer the front wheels 2, 2 to the right by a predetermined amount as much as possible to obtain a steering angle corresponding to this approach angle θ, and after a predetermined time, the front wheels 2, 2 are reversely steered to the left. As shown in FIG. 5, control is performed to follow the boundary with one steering operation.

Here, when the steering is started immediately after the approach angle θ is detected, as mentioned above, in the past, as shown by the dotted line in Fig. Vehicle body 1 was protruding from the ground. This occurs due to the so-called inner wheel difference, outer wheel difference, control response time, etc. caused by the fact that the copying sensor A is provided at the front of the vehicle body 1 and the steering wheels 2, 2 are the front wheels. It turned out to be something. Therefore, as described above, in order to correct the shift width L of the vehicle body 1 toward the mowed land side, the present invention provides control after entering the boundary, that is, with the optical sensor S ₁ , in accordance with the approach angle θ. A predetermined time T from the approach start time detected by the device 9
After the time has elapsed, the control device 9 is configured to start steering. The delay time T is stored in the memory 12 in advance in correspondence with the approach angle θ, and is read out in correspondence with the detection angle θ, using a so-called table reference method, but it may also be calculated by the CPU 11. .

After controlling the traveling direction to follow the boundary in this way, the optical sensors S ₂ and S ₃ perform normal tracing traveling control so that they continuously detect the boundary between the uncut field and the cut field. Therefore, regardless of the magnitude of the approach angle θ, the vehicle body 1 can be satisfactorily aligned with the predetermined position of the boundary, and the subsequent automatic tracing travel control can be performed satisfactorily.

16 is a hydraulic pump, and FIG. 6 is a flowchart showing a routine when the above-mentioned control device 9 enters the system. 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 6,
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 above approach routine, 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 tracing sensor according to the present invention, in which FIG. 1 is an overall plan view, FIG. 2 A is a front view of the main part, B is a schematic plan view thereof, and FIG. , Figures 4A and 4B are conceptual diagrams of approach angle detection, Figure 5 is a schematic plan view of the steering trajectory,
FIG. 6 is a flowchart showing the operation of the control device. 1...Vehicle body, 2...Front wheel, 9...Control device, A
...Tracking sensor, θ... Approach angle, T... Predetermined time.

Claims (1)

[Claims] 1. Tracing sensor A that detects a predetermined boundary of a running area
and a control device 9 that controls the vehicle body 1 to automatically travel along the detected boundary, [a] An approach angle θ of the vehicle body 1 with respect to the boundary and an approach angle θ. A means for detecting the start time is provided. [B] The control device 9 controls the detected approach angle θ.
The steering condition setting means is provided for setting a set time T and a steering amount corresponding to the above. [C] The control device 9 adjusts the approach angle θ after the predetermined time T has elapsed from the approach start time.
front wheels 2 in a predetermined direction with a steering amount corresponding to
The vehicle is equipped with approach direction control means that instructs the driver to steer the vehicle and to switch the vehicle after a certain period of time has elapsed. A traveling vehicle with a tracing sensor characterized by having the configuration described in [A] to [C] above.