JPH10164909A - Working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a working machine improving travel property without wastefully consuming power and fuel by providing a correcting means controlling a power steering device so as to reduce the frequency of steering operation maintaining traveling to a target direction by an automatic steering control means. SOLUTION: This machine is provided with an automatic steering controlling means E maintaining a steering direction to a previously set target direction by the driving force of an actuator based on the measuring result of a sensor such as a posture sensor 38 discriminating the traveling direction of a traveling device body when a steering operation tool travels in a non-operating state, a discriminating means discriminating displacing tendency to the right and left at the time of traveling by the steering operation tool or at the time of traveling by the means E, and the correcting means G controlling a power steering device in order to reduce the frequency of steering operation maintaining traveling in the target direction by the means E based on the discriminating result of this means F.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention includes a power steering device for steering a steered wheel by a driving force of an actuator in response to an operation of a steering operation tool. The present invention relates to an improvement of a working machine having automatic steering control means for maintaining a steering direction at a preset target direction by a driving force of the actuator based on a measurement result of a sensor for determining a traveling direction of a traveling body during traveling.

[0002]

2. Description of the Related Art Conventionally, when a riding type rice transplanter is taken as an example of a working machine configured as described above, it is necessary for the operator to perform straight running when transplanting seedlings, so that the operator must perform relatively delicate steering operations. When artificially replenishing the seedling planting equipment with spare seedlings during this operation, the operator should keep the hand off the steering operation tool and run the traveling machine straight. There has also been proposed a system that automatically performs steering control for a relatively short time.

[0003]

As described above, in consideration of the automatic control for making the traveling body travel straight, for example, when the tillage machine is tilted to the right or left, the steered wheels are moved straight forward. Even if it is set to, the traveling direction naturally tends to the lower side of the tillage, and when the traveling direction changes in this way, the steering operation for restoring the traveling direction of the traveling aircraft is automatically performed It will be. However, even in the automatic steering operation, when the inclination of the cultivator is large, the steering control is frequently performed, so that not only the seedlings transplanted in the field scene are disturbed, but also power and fuel are wasted. Consumption and room for improvement.

An object of the present invention is to rationally configure a working machine capable of reducing the control frequency during automatic steering control.

[0005]

According to a first aspect of the present invention, as described at the outset, a power steering apparatus for steering a steered wheel with an actuator based on an operation of a steering operating tool. And an automatic steering control means for maintaining the steering direction at a preset target direction with the driving force of the actuator based on the measurement result of the sensor when the steering operation tool is running in a non-operating state. The traveling operation tool, or, when traveling by the automatic steering control means, a discriminating means for discriminating a tendency of displacement in the left-right direction during traveling of the body, and based on a discrimination result of the discriminating means, Correction means for controlling the power steering device so as to reduce the frequency of the steering operation for maintaining the traveling in the target direction by the automatic steering control means. The action is as follows.

According to a second feature of the present invention (claim 2), in claim 1, the discriminating means determines whether the steering operation time to the left or right in a unit time is long or the steering angle is large. The processing system is configured to determine the tendency of displacement in the left-right direction during traveling of the aircraft by determining the tendency. The operation is as follows.

A third feature of the present invention (claim 3) is that, in claim 1, the discriminating means is supported rotatably around an axis in a front-rear posture with respect to the body, and has a roll-to-ground posture. It consists of a processing system that determines the tendency of displacement of the ground work device in the left and right direction during running of the aircraft based on the frequency of rolling within a unit time of the ground work device, and its operation is as follows. It is.

According to a fourth feature of the present invention (claim 4), according to claim 1, the correction means controls the steering direction of the steered wheel based on the target direction based on the determination result from the determination means. The point is that the processing system is directed to the side with higher frequency, and the operation is as follows.

A fifth feature of the present invention (claim 5) resides in claim 1, in which the correction means controls the steering operation force to the side with a higher operation frequency based on the determination result from the determination means. The operation of the processing system for adjusting the driving force of the actuator so as to make the driving force greater than the steering operation force to the opposite side is as follows.

[Operation] According to the first feature, the determining means determines the tendency of the traveling body to be displaced in the left-right direction.
At the time of steering by the automatic steering control means, the correction means reduces the frequency of the steering operation based on the result of this determination and causes the traveling body to travel in the target direction.

According to the second feature, since the tendency of displacement in the left-right direction during traveling of the aircraft is determined based on the operation time of the steering operation system or the steering angle, the actual operation can be performed without using special sensors. It is possible to determine an accurate tendency based on the steering control.

According to the third feature, since the tendency of displacement in the left-right direction during the traveling of the aircraft is determined based on the frequency of control for maintaining the ground rolling posture of the ground working device, for example, the right side of the ground working device is determined. If the frequency of control to raise is high, the aircraft tends to lean to the right, so the traveling direction tends to shift to the right based on the target direction, and the frequency of steering control to the left to correct this is high. Can be discriminated, and it is not necessary to use special sensors.

According to the fourth feature, the correction means directs the steering direction of the steered wheels in a direction with a high frequency of displacement based on the target direction based on the result of the determination by the determination means, so that the aircraft deviates from the target direction. By correcting the displacement in the direction in advance, the frequency of the steering operation by the automatic steering control means can be reduced.

According to the fifth feature, the correction means increases the steering operation force of the steered wheels on the side with the higher frequency of displacement based on the target direction based on the determination result of the determination means. As a result, the frequency of the steering operation by the automatic steering control means can be reduced as a result of performing the returning operation with a strong force even when the vehicle deviates from the position.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a drive-type front wheel 1 and a drive-type rear wheel 2 that are steered.
The engine 4 is mounted on the front of the traveling body 3 provided with a belt-type continuously variable transmission V and the transmission case 5 to which power from the engine 4 is transmitted. Also, a driver seat 6 is provided at the center of the traveling body 3.
And a steering handle 7 as a steering operation tool, and a seedling planting device A as a ground working device is placed in a front-rear position via a link mechanism 9 driven up and down by a lift cylinder 8 with respect to a rear end of the traveling body 3. Are connected so as to be freely rollable around the rolling axis X to form a riding type rice transplanter as a working machine.

The seedling planting apparatus A performs an operation of cutting out a mat-shaped seedling W placed on a seedling mounting table 10 by a planting mechanism 11 that operates in conjunction with a running speed and planting the seedling W in a field scene. The seedling planting operation is carried out in a state where the leveling float 12 is in contact with the ground, and the continuously variable transmission V has an endless belt on a split pulley type pulley provided on the output shaft of the engine 4 and the input shaft of the transmission case 5, respectively. In addition to winding, the speed is adjusted by adjusting the winding radius of the endless belt with respect to each pulley (specific structure is not described in detail).

As shown in FIG. 2, the link mechanism 9 includes a pair of left and right top links 9T and a pair of right and left lower links 9T.
L and a vertical link 9V connected to the rear ends of these links 9T and 9L.
Is supported swingably around the rolling axis X with respect to the lower end of the roller. Further, a screw shaft 16 in a horizontal position is rotatably supported with respect to a frame 15 fixed on the upper surface of the vertical link 9V, and an electric rolling motor 17 is provided to drive the screw shaft 16 to rotate forward and reverse. , Screw shaft 1
The operating spring 21 is interposed between the shift member 19 that moves integrally with the nut member 18 screwed into the nut 6 and the left and right vertical frames 20 on the side of the seedling planting apparatus. The rolling posture of A is configured to be freely changeable. In addition, a weight-type rolling sensor 22 is provided on the side of the seedling mounting table 10 opposite to the seedling-mounting surface, and the rolling sensor 22 measures the hanging attitude of the weight by using a potentiometer-type sensor to measure the rolling attitude of the seedling mounting apparatus A. It is configured to be.

As shown in FIG. 3, an alternator 25 is provided on the right side of the engine 4, a battery 26 is disposed on the left side of the engine 25, and a micro-cell is provided below the steering handle 7 and above the transmission case 5. A control device 27 containing a processor is arranged, and the position of the spark plug 4P of the engine 4 is arranged on the entire surface of the engine so that electromagnetic noise from the spark plug 4P of the engine 4 hardly acts on the control device 27. Engine 4
A shield 28 made of a metal plate is arranged between the control device 27 and the control device 27. In addition, the ignition plug 4P and the alternator 2 are connected via a power line 29 from the battery 26 to the control device 27.
5 so that the electromagnetic noise from
Is arranged on the side of the engine 4 opposite to the alternator.

As shown in FIG. 4, a tie rod 32 for connecting left and right knuckle arms 31 of the front wheel 1 and a pitman arm 34 of a gear case 33 at the base end of the steering handle 7 are mechanically linked to each other for steering. An operation system is configured, and at the time of steering operation (at the time of steering)
A torque sensor 35 for measuring the torque and operation direction of the steering wheel is provided on the operation shaft of the steering handle 7, and an electric assist motor 36 is used as an actuator for applying an assist force to the steering operation system based on the measurement result of the torque sensor 35. Equipped and one knuckle arm 3
A power steering apparatus is provided with a potentiometer-type steering angle sensor 37 for measuring a steering angle (steering angle) of the front wheel 1 at a base end of the power steering apparatus.

The rice transplanter is provided with a magneto-sensitive or laser gyro-type attitude sensor 38 (see FIG. 3) for judging a change in the traveling direction of the traveling body 3, and a signal from the attitude sensor 38. By setting the control operation of the control device 27 so that the traveling body 3 travels straight based on the operator, for example, when the operator supplies the preliminary seedlings to the seedling planting device A, the operator can operate the steering wheel 7 from the steering handle 7. The power steering device is automatically controlled even when the hand is released, and the traveling body 3 is maintained in the straight traveling posture by the operation force from the power steering device.

As shown in FIG. 5, the torque sensor 35 and the turning angle sensor 37
The attitude sensor 38 and a selection switch 39 for selecting automatic steering control for automatically moving the traveling body 3 straight ahead.
And an input system from the rolling sensor 22 and a rolling angle setting device 40 for arbitrarily setting the rolling angle of the seedling planting apparatus A.
7, and an output system for the assist motor 36 is formed, and the control operation is set as follows.

FIG. 6 shows a main control operation. In this control, when the control is started, an initial value is set as a discrimination value, and an automatic steering routine is executed only when the selection switch 39 is ON. (Steps # 101, # 102, # 200), the control for executing the next determination routine is repeated until reset (# 300, # 10).
3 steps). The control for maintaining the seedling planting apparatus A at the set value of the rolling angle setting device 40 is not described because it is not directly related to the present invention. The discriminating means F is constituted by a program constituting a discriminating routine.

Automatic steering routine, discrimination routine (# 20)
0, # 300 step) are set in the form of a subroutine, and the automatic steering routine (# 200 step) sets a steering reference target based on a determination value set in a determination routine described later, as shown in a flowchart of FIG. The signal from the turning angle sensor 37 is input, and it is determined whether the signal value from the turning angle sensor 37 exists in a dead zone set based on the value of the steering reference target. The assist motor 36 is controlled only toward the steering reference target (steps # 201 to # 204).

This steering reference target is to set the turning angle of the front wheel 1 when the steering handle 7 is not operated. When the discrimination value is the initial value, the steering wheel is directed straight ahead, and the discrimination will be described later. When a value is set, the turning angle of the front wheel 1 is set to one of the left and right directions based on the straight traveling direction based on the determination value. After the steering reference target is set in this manner, the assist motor 3 can be operated without the operator operating the steering handle 7.
The steering operation is automatically performed with the driving force of No. 6, and the steering angle is maintained.

Next, a steering torque is set on the basis of the discrimination value, and a signal from the attitude sensor 38 is input. The measured value from the attitude sensor 38 is used to determine a target attitude corresponding to a preset straight traveling direction. It is determined whether or not it exists within the dead zone set as a reference, and if it does not exist, the assist motor 36 is driven toward the target posture, and at this drive, the assist motor 36 is driven with the set steering torque ( # 205 to # 208 steps). It should be noted that the steering torque is to make the torque to the side where the steering operation is frequently performed higher than the torque to the other side. This steering torque is obtained by changing the power supplied to the assist motor 36 to the duty ratio of the intermittent power. The torque value is increased by increasing the value in the PWM method as in the case of the adjustment, and the value of the torque is decreased by decreasing the electric power.

That is, the target posture is controlled by the control of retaining the signal of the posture sensor 38 in the memory when the work is started or when the turning of the body 3 on the headland is completed, and the body 3 is turned to the direction in which it is to be run. In this control, when the automatic cruise control is selected by operating the selection switch 39 at the time of work and the posture of the body 3 deviates from the target posture, the operator does not need to perform the steering operation. The target posture is automatically restored by the driving force of the assist motor 36. The correcting means G is constituted by steps # 201 to # 204, and the automatic control means E is constituted by steps # 206 to # 208.

The discrimination routine (step # 300) is performed even when the steering handle 7 is manually operated.
Even in the steering control by the automatic steering routine described above,
The left or right steering operation is determined based on the left / right steering operation of the front wheel 1 based on the attitude of the front wheel 1 in the straight traveling direction. At the time of steering operation, it is determined whether the vehicle is in a straight running state based on a signal from the torque sensor 35 (it may be determined whether the vehicle is in a straight running state from the control state of the assist motor 36), and an automatic steering routine is performed. At the time of steering control, it is determined from the control state of the assist motor 36 whether or not the vehicle is in a straight running state. When it is determined that the steering operation is performed, a process of increasing the count value of the left counter or the right counter set corresponding to the steering direction by a predetermined value is performed (# 3). 1 # 305 steps).

Each of the left counter and the right counter is constituted by software for storing a count value in a specific register in a microprocessor or a specific address of a memory, as long as the steering operation state to the left and right continues. The processing mode is set so as to increase the count value.

Next, every time the interval timer which times up at the set time interval times up, the value of the left counter and the value of the right counter are divided (calculated) to determine the frequency of the steering operation on the left and right sides. Then, a process of setting a discrimination value from the calculation result (steps # 306 to # 308) is performed.

Similarly to the above, the interval timer is constituted by software for storing a count value in a specific register in a microprocessor or a specific address of a memory, and increments the count value with the passage of time ( When the count value reaches a preset value, the time is up and the above-described processing is performed, and at the same time, the count value is cleared so that the initial value of “0” is set. Is set.
The frequency obtained from the count values of the left and right counters is merely a numerical value, but data such as a table is set in advance in the memory of the control device 27 so as to set a discrimination value corresponding to the numerical value. The discrimination value set based on this is a value corresponding to the steering reference target.

Specifically, an input system from the turning angle sensor 37 is provided with an A / D converter (not shown) having a performance of about 8 bits, and is used when the turning angle of the front wheel 1 is set to go straight. ,
For example, when the A / D converter has an 8-bit performance, the value of the steering reference target is expressed as a numerical value of “128” (decimal system). Is smaller than the numerical value of “128”, the value of the steering reference target on the right side with respect to straight traveling is larger than the numerical value of “128”. When the frequency of the leftward steering operation is high, the higher the frequency, the more the discrimination value is set to “12”.
The processing mode is set so as to be smaller than the numerical value of "8", and when the frequency of the rightward steering operation is high, the processing mode is set so that the higher the frequency, the larger the discrimination value becomes larger than the numerical value of "128" By doing so, the discrimination value can be directly set to the value of the reference target.

As described above, according to the present invention, even when the steering handle 7 is set in the straight traveling direction, for example, in a field where the cultivator is inclined in either the left or right direction, the cultivator is directed toward the lower slope side. In a field operation in which the attitude (running direction) of the body 3 naturally changes, the frequency of operating the steering handle 7 in a direction to correct the natural change of the body attitude increases. The frequency is obtained in advance (the frequency of the steering direction at the time of the automatic driving control is also obtained in the above-described processing), and the selection switch 39 is set to automatically move the body 3 straight ahead by the automatic steering control during the work. By simply turning on the vehicle, the steering operation is performed on the side where the control device 27 corrects the traveling direction of the front wheel 1 based on the frequency obtained as described above. As a result, a natural displacement in the traveling direction is obtained. Was fixed The steering control cancels out the frequency of the steering control at the time of the automatic steering, and furthermore, the steering operation is strongly performed at the time of the steering control based on the signal from the attitude sensor 38, and the operation to the high frequency side is strongly performed. Correction of the steering direction can be quickly performed by performing the operation with an appropriate operation force (torque).

[Other Embodiments] In addition to the above-described embodiment, the present invention assumes the degree of inclination of the cultivator in the left-right direction based on the frequency of rolling control of the seedling planting apparatus A, for example.
It is also possible to configure to execute the same automatic steering routine as described above, and in this alternative embodiment, the determination routine can be configured as shown in the flowchart of FIG. In this alternative embodiment, those having the same functions as those of the above-described embodiment are denoted by the same reference numerals as those of the above-described embodiment,
Add a sign.

That is, the determination routine (# 400 step) is a routine for determining the direction and frequency at which the steering wheel 7 will be steered based on the data on which side of the rolling motor 17 has been driven. In this process, it is determined whether the attitude of the seedling placement apparatus A with respect to the traveling machine body 3 is horizontal (parallel) based on the control signal to the rolling motor 17, and if the attitude is horizontal, The operation of the left and right counters (to be described later) is stopped, and if it is determined that the rolling motor 17 is driven in the “left-up” direction or the “right-up” direction, Then, a process of increasing the count value of the left counter or the right counter set by a predetermined value is performed (steps # 401 to # 405).

Each of the left counter and the right counter is constituted by software so as to store a count value in a specific register in a microprocessor or a specific address of a memory, and counts as long as the steering operation state continues. The processing mode is set so as to increase the value.

Next, each time the interval timer that counts up at a set time interval counts up, the value of the left counter and the value of the right counter are divided (calculated) to calculate the frequency of the steering operation on the left and right sides. Is determined, and a discrimination value is set from the calculation result (steps # 406 to # 408).
Perform processing.

The interval timer is also configured by software to store the count value in a specific register in a microprocessor or a specific address of a memory, as described above, and increments the count value with the passage of time. When the count value reaches a preset numerical value, the time is up and the above-described processing is performed, and the processing form is set so that the count value is cleared and becomes the initial value of “0”. ing.

In the present invention, it is possible to increase the correction value as the turning angle of the steered wheels increases.

[0039]

Therefore, during automatic steering control, the steered wheels are turned in advance in a direction to reduce the frequency of the steering operation, whereby the frequency of the steering operation is reduced, and the vehicle can travel straight ahead in the target direction with high precision. The work machine was rationally configured (claim 1). In particular, when the discriminating means performs processing based on the operation frequency of the steered wheels, it is possible to discriminate the actual displacement tendency and provide highly accurate straight traveling without providing special sensors. , The discriminating means performs processing based on the frequency of rolling of the ground work equipment, enabling accurate straight-line running by accurately discriminating the displacement in the running direction due to the inclination of the ground without special sensors When the steering direction of the steered wheels is turned based on the determination result, the phenomenon that the traveling direction of the body naturally displaces from the target direction is canceled in advance to enable straight traveling. In the case where the steering operation force of the actuator is changed based on the determination result, even when the aircraft deviates from the target direction, the restoration to the straight traveling can be smoothly performed by the strong restoration operation. Comprising (claim 5).

[Brief description of the drawings]

FIG. 1 is an overall side view of a rice transplanter.

FIG. 2 is a front view of the seedling planting apparatus.

FIG. 3 is a schematic side view of a front part of the fuselage.

FIG. 4 is a schematic diagram of a steering control system.

FIG. 5 is a block circuit diagram of a control system.

FIG. 6 is a flowchart of a main control operation.

FIG. 7 is a flowchart of an automatic steering routine.

FIG. 8 is a flowchart of a determination routine.

FIG. 9 is a flowchart of a determination routine according to another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steering wheel 7 Steering operation tool 36 Actuator 38 Sensor A Ground work equipment E Automatic steering control means F Discriminating means G Correcting means X Axis

Claims (5)

[Claims] A power steering device that steers steering wheels in response to an operation of a steering operation tool by a driving force of an actuator; A working machine comprising automatic steering control means for maintaining a steering direction at a preset target direction with a driving force of the actuator based on a measurement result of a sensor for determining a traveling direction, wherein When the vehicle is traveling or when the automatic steering control unit is traveling, the automatic steering control unit includes a determination unit configured to determine a tendency of displacement in a left-right direction during travel of the vehicle, and based on a determination result of the determination unit, the target determined by the automatic steering control unit. A work machine including a correction unit that controls the power steering device so as to reduce the frequency of a steering operation for maintaining traveling in a direction. 2. The method according to claim 1, wherein the determining unit determines whether the steering operation time to the left or right in the unit time is long or the steering angle is large, and thereby determines whether the steering operation is performed in the left-right direction during the vehicle traveling. 2. The work machine according to claim 1, comprising a processing system for determining a displacement tendency. 3. The apparatus according to claim 1, wherein the determining means is rotatably supported around an axis in a front-rear posture with respect to the body, and is configured to maintain a ground rolling posture. 2. The work machine according to claim 1, wherein the work machine is configured to determine a tendency of displacement in a left-right direction during traveling of the machine based on the frequency. 4. The processing system according to claim 1, wherein the correction unit is configured to direct the steering direction of the steered wheel to a side where the operation frequency is higher based on the target direction based on a determination result from the determination unit. The working machine described. 5. A driving force of an actuator based on a result of the discrimination from the discriminating means, the driving force of the actuator being adjusted so that a steering operation force on a side with a higher operation frequency is larger than a steering operation force on a reverse side. 2. The working machine according to claim 1, wherein the working machine is configured by a processing system that performs processing.