JPH0543204U - Automatic steering guidance device - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] The traveling vehicle 1 is displaced laterally by a predetermined offset with respect to the guide cable 22 in accordance with the number of times of traveling, and the front and rear wheels of the traveling vehicle 1 are driven. Prevents the formation of deep ruts on the ground in orchards. [Structure] The magnetic field strength of the induction cable 22 is detected by the magnetic sensor 21 of the traveling vehicle 1, and the cable 2 is detected from the detected value.
In the automatic travel guidance device that calculates the lateral deviation amount of the vehicle 1 with respect to 2 and controls the vehicle 1 in the direction in which the deviation amount decreases, the cable 22 from the magnetic sensor 21 when the cable 22 is located at the center position of the vehicle 1 A target setter 23 for setting an arbitrary offset value to the output value to adjust the target value is provided, and the vehicle 1 is connected to the cable 22 based on the comparison between the target value by the setter 23 and the output value by the magnetic sensor 21. On the other hand, steering control is performed by offsetting to the left and right by the offset amount.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention is an automatic steering guidance device used for chemical sprayers (speed sprayers) used in orchards and unmanned vehicles in factories, and more specifically, from guidance cables arranged along the guidance path. The present invention relates to an automatic steering guide device which automatically steers a traveling vehicle along the cable while detecting the intensity of a magnetic field generated by a magnetic sensor provided in the traveling vehicle.

[0002]

[Prior Art]

 Conventionally, as this type of automatic steering guidance device, an AC current generator is connected to an induction cable laid on the ground along the guidance path, and an alternating current is passed from the generator to the cable, Magnitude of lateral displacement of the center of the traveling vehicle in the width direction with respect to the cable is detected by detecting a change in the intensity of the transmitted electromagnetic wave, that is, the strength of the magnetic field generated around the circumference of the cable, with a pair of left and right magnetic sensors provided in the traveling vehicle. Based on the difference between the output values from the magnetic sensors corresponding to the above, the magnitude of the lateral deviation (deviation amount) and the direction of lateral deviation (determination of right or left) with respect to the cable of the traveling vehicle are determined. Detecting and controlling the direction of the steered wheels in the traveling vehicle based on these detection results, and performing automatic steering control so that the traveling vehicle travels along the cable. It is known. (See Japanese Utility Model Publication No. 2-70211).

[0003]

[Problems to be solved by the device]

 However, the above-mentioned automatic steering guidance device is installed in, for example, a speed sprayer, and the speed sprayer is automatically steered so that the center portion in the width direction passes along the line of the guidance cable laid in the orchard. For example, when the chemical spraying work is performed on the speed sprayer, since the steering wheel of the speed sprayer always automatically travels along the guide cable in a predetermined guide path accurately, it is necessary to repeat the chemical spraying work. As a result, a deep rut is formed on the guide path by the steering wheel, which may be an obstacle when the weeds are mowed under the orchard, or by the ruts on the ground of the orchard. There was a problem that a deep pool of water was created, which adversely affected the growth of trees.

An object of the present invention is to allow a traveling vehicle to be arbitrarily deviated in the left-right direction with respect to a guide cable for steering control, and prevent a deep rut from being formed by the steering wheels of the traveling vehicle. An object is to provide an automatic steering guidance device that can be used.

[0005]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention detects the magnitude of the magnetic field generated from a guide cable 22 arranged along a guide path by a magnetic sensor 21 provided in a traveling vehicle 1. Then, the amount of deviation of the traveling vehicle 1 with respect to the guide cable 22 in the left-right direction is calculated from the output value of the sensor 21, and the automatic traveling guidance that controls the traveling of the traveling vehicle 1 in the direction in which the deviation amount decreases. In the device, a target setter 23 that sets a target value changeable by adding or subtracting an arbitrary offset value to the output value from the magnetic sensor 21 when the guide cable 22 is located at the center position of the traveling vehicle 1 is provided. Based on the comparison between the target value set by the setting device 23 and the output value set by the magnetic sensor 21, the running vehicle 1 is offset to the guide cable 22 by an offset amount in the left and right direction of the running vehicle 1 for steering control. It is characterized in that it has configured to.

[0006]

[Action]

 In the case where the traveling vehicle 1 is automatically steered by the above automatic steering guidance device, the target setting device 23 is operated to operate the guide cable 22 at the center position of the traveling vehicle 1. The target value set by the target setting device 23 is set by arbitrarily setting the target value for driving the traveling vehicle 1 by adding or subtracting an arbitrary offset value to the output value from the magnetic sensor 21 by the target setting device 23. Based on the comparison between the value and the output value from the magnetic sensor 21, the traveling vehicle 1 is laterally displaced with respect to the guide cable 22 by a predetermined offset and is controlled to travel. As a result, the steering wheel of the traveling vehicle 1 forms a deep rut on the ground or the like by arbitrarily setting the target value by the target setter 23 according to the number of times the traveling vehicle 1 performs the work. Are blocked.

[0007]

【Example】

 The drawings show an embodiment in which the automatic steering guide device according to the present invention is applied to a speed sprayer for spraying chemicals. A traveling vehicle 1 which is a speed sprayer is mounted on the front part of a vehicle body 2 as shown in FIG. A driving control unit 4 having a handle 3 is provided, a chemical liquid tank 5 is provided at the rear portion of the vehicle body 2, and a spraying unit 6 is provided at the rear portion thereof.

The spray section 6 includes a large number of spray nozzles 7 provided radially outward at appropriate intervals on the outer periphery of the vehicle body 2 excluding the lower surface of the vehicle body 2, and a blower for sending air outward in the radial direction (shown in the figure). The spray nozzle 7 is in communication with the chemical liquid tank 5 via a pump and a flow rate control valve that can be shut off. The spraying direction can be changed to one or all of the directions, and for example, spraying can be controlled so that the spraying work can be performed in every three or every two sections.

Further, in the figure, reference numerals 8 and 8 are left and right front wheels, and 9 and 9 are left and right rear wheels. The drive system of these four wheels is as shown in FIG. Is a so-called four-wheel drive type in which each wheel is transmitted to and driven by a traveling speed change mechanism M. Further, each of the four wheels is driven by a front steering device 10 and a rear steering device 11. It is a so-called four-wheel steering type that can change the direction.

The front steering device 10 and the rear steering device 11 turn the left and right front wheels 8, 8 and the left and right rear wheels 9, 9 by operating a pair of left and right hydraulic cylinders 12, 13 attached to a steering mechanism. It can be changed.

The front and rear steering devices 10, 11 are controlled by the control hydraulic circuit 14 shown in FIG. 4, that is, the control hydraulic circuit 14 is connected to the hydraulic pump 15 in three positions. Hydraulic oil is supplied to the hydraulic cylinder 12 of the front steering device 10 via the port type solenoid switching valve 16 and to the hydraulic cylinder 13 of the rear steering device 11 via the 3-position 4-port electromagnetic switching valve 17. The hydraulic cylinders 12 and 13 are individually operated by this hydraulic oil to control the steering of the front and rear wheels 8 and 9. In the figure, reference numeral 18 is a steering angle sensor for detecting the steering angle on the front wheel 8 side, and 19 is a steering angle sensor for detecting the steering angle of the rear wheel 9.

Further, the control hydraulic circuit 14 is provided with a steering control device 20 for controlling the switching of the electromagnetic switching valves 16 and 17, and based on a command from the steering control device 20, the electromagnetic switching valves are controlled. By controlling switching of 16 and 17, steering control of the front and rear wheels 8 and 9 is performed through the hydraulic cylinders 12 and 13.

Further, the traveling vehicle 1 is provided with a magnetic sensor 21 for detecting a magnetic field intensity generated around an induction cable, which will be described later. In FIG. 5, the magnetic sensor 21 is used as the traveling vehicle 1 described above. A pair of left and right magnetic sensors 21a and 21b are arranged at both sides of the front lower surface of the vehicle at regular intervals from the center position in the vehicle width direction. As each of the sensors 21a and 21b, for example, a pickup coil in which a conductor is wound in a coil shape, a Hall element, a Hall IC, a magnetic resistance element, a magnetic transistor, or the like is used.

In FIG. 5, an induction cable 22 is laid in a groove A provided along the traveling guide route of the traveling vehicle 1 on the ground such as an orchard, and the induction cable 22 is provided with an AC current generating device in a predetermined manner. An electromagnetic wave transmitted from the induction cable 22, that is, an AC magnetic field strength generated around the induction cable 22, is sensed by the pair of left and right coil-type magnetic sensors 21a and 21b by applying an alternating current having a frequency. The case is schematically shown.

In this case, the absolute value of the voltage | e1 | generated in the right magnetic sensor 21a corresponding to the strength of the alternating magnetic field and the left magnetic sensor 21b corresponding to the strength of the alternating magnetic field. The difference e from the absolute value | e2 | of the voltage value is expressed by the following equation.

[0016]

[Equation 1]

Further, in FIG. 6, the difference e is plotted on the vertical axis, and the lateral deviation distance (m) of the traveling vehicle 1 with respect to the guide cable 22 is plotted on the horizontal axis to show the change relationship between the two. From the figure, the lateral deviation direction (right or left) of the traveling vehicle 1 with respect to the guide cable 22 and the lateral deviation deviation amount can be known. The frequency of the alternating magnetic field applied to the induction cable 22 is about 1.5 KHz to 10 KHz. Further, the guide cable 22 may be directly laid on the ground or may be buried in the ground without forming the groove A on the ground as described above. It is also possible to generate a magnetic field by passing a direct current or by placing a pulse signal on the direct current, and the induction cable 22 may be a single wire, or it may be parallel to the left and right at appropriate intervals. It may be a so-called stereo type which is installed in the. Further, as the guide cable 22, a normal wire having a circular cross section or a flat strip is used.

When the traveling vehicle 1 is automatically steered, the lateral deviation amount and lateral deviation direction (right or left) of the traveling vehicle 1 with respect to the guide cable 22 are detected based on the detection results from the magnetic sensors 21a and 21b. ) And a central processing unit, which will be described later, incorporated in the steering control device 20, and the electromagnetic switching valves 16 and 17 are switch-controlled by an output command from the steering control device 20 based on the calculation result. As a result, the steering control of the front and rear wheels 8 and 9 is performed via the hydraulic cylinders 12 and 13, and the automatic steering control is performed so that the traveling vehicle 1 always travels along the guide cable 22. It is.

In the automatic steering guidance device as described above, however, the front and rear wheels 8 and 9 provided on the traveling vehicle 1 always automatically and automatically guide the predetermined guidance route along the guidance cable 22. By repeating this automatic steering operation, a deep rut can be created by the front and rear wheels 8 and 9 in the guide path, which can be an obstacle when weeding the undergrowth of an orchard. In order to prevent ruts from being formed in the guide path by the front and rear wheels 8 and 9, a deep pool of water may be formed on the ground of the garden, which may adversely affect the growth of trees. In addition, it was configured as follows.

That is, when the center position in the vehicle width direction of the traveling vehicle 1 is located at a position facing the guide cable 22, an arbitrary offset value is added to or subtracted from the output value output from each of the magnetic sensors 21a and 21b. Then, a target setting device 23 for variably setting a target value which is a traveling target of the traveling vehicle 1 is provided, and the setting device 23 is incorporated in the steering control device 20 so that the target value by the setting device 23 and the By the output from the steering control device 20 based on the comparison with the output values from the magnetic sensors 21a and 21b, the traveling vehicle 1 is steered by offsetting the guide cable 22 in the left and right directions by the offset amount. I controlled it.

More specifically, FIG. 1 shows a control block diagram of the steering control device 20, in which the magnetic sensors 21a and 21b are connected to the input side of a central processing unit 24 including a microcomputer. The target setter 23, an automatic switch 25 that switches when the vehicle 1 is automatically steered, and a manual switch 26 that switches when the vehicle 1 is manually steered are connected to each other, and the output side of the central processing unit 24 is connected. In the above, by turning ON / OFF the electromagnetic solenoid of the electromagnetic switching valve 16 that supplies hydraulic oil to the hydraulic cylinder 12 of the front steering apparatus 10, the electromagnetic switching valve 16 is switched to three positions. A front right steering excitation circuit 27 for steering the front wheels 8 to the right, a front left steering excitation circuit 28 for steering the front wheels 8 to the left, and the rear steering device 11 When the rear wheel 9 is steered to the right by turning ON / OFF the electromagnetic solenoid of the electromagnetic switching valve 17 that supplies hydraulic oil to the hydraulic cylinder 13 to switch the electromagnetic switching valve 17 between three positions. The front right steering excitation circuit 29 and the front left steering excitation circuit 30 for steering the rear wheel 9 to the left are respectively connected.

Next, the control mode by the above-described steering control device 20 will be described based on the flowchart shown in FIG. First, it is determined whether offset input is to be performed at the start of the start (step 1), that is, the offset value set by the target setting unit 23 is updated when the automatic switch 25 is on. It is determined whether or not to execute, and if the result is YES, the offset value (Voff) is arbitrarily updated in the target setting device 23 in step 2. Then, in step 3, when the center position in the vehicle width direction of the traveling vehicle 1 is located at the facing position facing the guide cable 22, the median value (Vc) output from each of the magnetic sensors 21a and 21b. The updated offset value (Voff) is added or subtracted to set the target value (Vg), which is the running target of the running vehicle 1, and then, in step 4, detected by the magnetic sensors 21a and 21b. The excitation circuits 27 to 30 are controlled so that the difference between the current value (V o) of the traveling vehicle 1 and the target value (Vg) is equal to or smaller than a predetermined threshold value (Vd). The steering control is completed.

As described above, the offset value (Voff) is arbitrarily updated by the setter 23 according to the number of times the traveling vehicle 1 travels, and the target value (Vg) is set. Based on the comparison between the value (Vg) and the current value (Vo) detected by the magnetic sensors 21a and 21b, the front and rear wheels 8 and 9 of the traveling vehicle 1 are operated via the excitation circuits 27 to 30. By controlling the direction, the front and rear wheels 8 and 9 of the traveling vehicle 1 are prevented from passing through the same place on the ground a number of times, and a deep rut is prevented from being formed on the ground.

In addition, in the case of No in step 1, that is, the automatic switch 25 is turned on, and the automatic steering of the traveling vehicle 1 is performed without updating the offset value by the target setting device 23. When performing, the operation in the steps 3 and 4 is directly performed without performing the operation in the step 2.

Further, when the manual switch 26 is turned on and the traveling vehicle 1 is manually operated, the respective excitation circuits 27 to 30 are manually controlled without the flow chart as described above. While steering, each of the front and rear wheels 8 and 9 is steered.

In addition, in the above automatic steering guidance device, when ultrasonic sensors or the like are provided in front of and on the left and right of the traveling vehicle 1, and when the sensors detect obstacles such as sticks that support trees in the orchard. Alternatively, the offset value may be switched by the target setter 23 by remote control or the like. In such a case, an obstacle such as the rod may be removed without changing the laying position of the induction cable 22. It can be avoided.

[0027]

[Effect of the device]

 As described above, according to the present invention, the magnitude of the magnetic field generated from the guide cable 22 arranged along the guide path is detected by the magnetic sensor 21 provided in the traveling vehicle 1, and The automatic guide device for calculating the lateral displacement of the traveling vehicle 1 with respect to the guide cable 22 from the output value of the sensor 21 and controlling the traveling of the traveling vehicle 1 in the direction in which the displacement amount decreases, A target setter 23 is provided for setting the output value from the magnetic sensor 21 when the vehicle 22 is located at the center position of the traveling vehicle 1 by adding or subtracting an arbitrary offset value so that the target value can be changed. 23. Steering control is performed by displacing the traveling vehicle 1 with respect to the guide cable 22 in the left-right direction of the traveling vehicle 1 based on the comparison between the target value of 23 and the output value of the magnetic sensor 21. According to the configuration, the target value is changed by arbitrarily adjusting the offset value with the target setting unit 23 according to the number of times of traveling, and the traveling vehicle 1 is moved to the guide cable 22 by a predetermined offset amount. By shifting the vehicle in the direction, the front and rear wheels of the traveling vehicle 1 can prevent the formation of a deep rut on the ground such as an orchard, and this rut cuts undergrowth of the orchard. It is possible to prevent it from sometimes disturbing, and to prevent a deep pool of water from the ruts on the ground of the orchard from adversely affecting the growth of trees.

[Brief description of drawings]

FIG. 1 is a block diagram of an automatic steering guide device according to the present invention.

FIG. 2 is a flow chart diagram of the automatic steering guide device.

FIG. 3 is a perspective view of a medicine spraying machine.

FIG. 4 is a hydraulic circuit diagram for controlling a front and rear steering device.

FIG. 5 is a diagram showing a relationship between an induction cable and a magnetic sensor.

FIG. 6 is a diagram showing a relationship between left and right positions of left and right magnetic sensors with respect to an induction cable and detection positions.

[Explanation of symbols]

 1 traveling vehicle 21 magnetic sensor 22 induction cable 23 target setter

Claims (1)

[Scope of utility model registration request] 1. A magnetic sensor 21 provided in a traveling vehicle 1 detects the magnitude of the strength of a magnetic field generated from an induction cable 22 arranged along a guide path, and from an output value of the sensor 21, In an automatic steering guidance device that calculates a lateral deviation amount of the traveling vehicle 1 with respect to the guidance cable 22 and controls the traveling of the traveling vehicle 1 in a direction in which the deviation amount decreases, the guidance cable 22 is the traveling vehicle. A target setting device 23 for setting an output value from the magnetic sensor 21 when it is located at the center position of 1 so that the target value can be changed by adding or subtracting an arbitrary offset value is provided. It is characterized in that the traveling vehicle 1 is deviated in the left-right direction of the traveling vehicle 1 by an offset amount with respect to the guidance cable 22 based on the comparison of the output values of the sensor 21 to perform steering control. Automatic steering guidance device.