JP3828059B2 - Automatic plowing control device for agricultural tractors - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an automatic tilling depth control device for agricultural tractors.
[0002]
[Prior art]
As an automatic tiller control device for an agricultural tractor, for example, as disclosed in Japanese Patent Application Laid-Open No. 2002-17114, a rotary tiller is connected to the rear part of the tractor main body so as to be movable up and down, and the rear part of the rotary tiller is moved up and down. The cover sensor (plowing depth sensor) detects the swinging position of the rear cover that can be swung so that the detected value from this cover sensor and the target plowing depth set by the plowing depth setting device are balanced. In many cases, the rotary tiller is configured to move up and down.
[0003]
[Problems to be solved by the invention]
Since the rear cover in the automatic tilling control device is grounded at a position several tens of centimeters behind the center of the rotary tillage unit, the rear cover acts on the soil that has been dug up by the rotary claws and raised upwards from the present time. After moving forward some distance. Therefore, when the raising / lowering control is performed based on the current detection value of the cover sensor, even if the detection value is balanced with the target value, the raising control is further performed due to the embankment that is delayed, and an overshoot occurs. When this continues continuously, a large undulation occurs.
The slower the travel speed is set, the less such a phenomenon occurs. However, the travel speed cannot be reduced from the viewpoint of workability, and the above phenomenon occurs more or less. .
[0004]
The present invention has been made paying attention to such points, and by correcting the detection value from the cover sensor reasonably, the adverse effect due to embankment is reduced and the occurrence of overshoot is suppressed. The main purpose is to be able to.
[0005]
[Means for Solving the Problems]
[Configuration, Action, and Effect of Invention of Claim 1]
[0006]
According to the first aspect of the present invention, a rotary tiller is connected to the rear portion of the tractor main unit so as to be movable up and down, and a swing position of a rear cover provided on the rear portion of the rotary tiller so as to be vertically swingable is detected by a cover sensor. In the automatic tilling control device for agricultural tractors configured to raise and lower the rotary tilling device by feedback control so that the detection value from this cover sensor and the target value set by the tilling depth setting device are balanced,
The actual detection value from the cover sensor is sampled for each set travel distance, and the direction of the lift control command and the actual lift operation direction are both upward directions from the direction of the lift control command and the actual lift operation direction at that time. In this case, the correction flag value set corresponding to the case where the direction of the elevation control command and the actual elevation operation direction are both downward, or the direction of the elevation control command and the actual elevation operation direction are upside down. the stored stored, the stored correction values are calculated by integrating multiplied by weighting factor correcting flag value and correcting flag value of the current past setting number, the actual detection value of the current on the basis of the correction value And a detected value correcting means for correcting the detected value as a control detected value for comparison with the target value.
[0007]
According to the above configuration, the actual detection value from the currently read cover sensor is not directly compared with the target value, but a weighting coefficient is applied to the stored past predetermined number of correction flag values and the current correction flag value. Based on the correction value obtained by multiplication and integration, the actual detection value at the present time is corrected, and the correction detection value obtained in this way is compared with the target value. Will be.
[0008]
For example, when the actual detection value from the cover sensor is set to be smaller as the rear cover is lifted and swung, the direction of the lift control command and the actual lift operation direction at the time of sampling are both “up” The flag value of the correction flag is (+1). If both the direction of the lift control command and the actual lift operation direction are “down”, the flag value of the correction flag is (−1), and the lift is performed. the flag value of the correction flag in the absence (0), and when the actual lifting operation direction to the direction of the elevation control command is different from previously set the correction flag value (0), stored for each sampling Detected by calculating the correction value by multiplying the previous predetermined number of correction flag values and the current correction flag value by the weighting coefficient and integrating them, and adding this to the actual detection value to compare with the target value Value and It's that. According to this, for example, when the actual plowing depth is deeper than the target plowing depth and the rise control is performed, the integrated value of the value obtained by multiplying the stored past correction flag value by the weighting coefficient becomes a positive value and corrected. The detection value is larger than the actual detection value. Therefore, before the actual detection value reaches the target value, the lift control command is in a neutral stop state in balance with the target value. Therefore, even if the cover sensor reaches the rising point of the soil, the rising control is not immediately executed based on the actual detection value at that time.
[0009]
Therefore, according to the first aspect of the present invention, it is possible to perform the tilling control with less undulation that suppresses the occurrence of overshoot by reducing the adverse effects caused by the delayed embankment.
[0010]
Further, according to the above configuration, appropriate correction can be performed by adjusting the degree of influence of the past control behavior.
[0011]
[0012]
[0013]
[Configuration, Action, and Effect of Invention of Claim 2 ]
[0014]
The invention according to claim 2 is the invention of claim 2, the correction flag value multiplied by a weighting factor, a correction flag value of the correction flag value and the time point close to this at the present time.
[0015]
According to the above configuration, correction that is strongly influenced by the control behavior in the past time zone close to the present time can be performed, and the elevation control can be smoothly performed toward the target value while further reducing overshoot.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an agricultural tractor. This agricultural tractor has a structure in which a rotary tiller 4 is connected to the rear portion of the tractor main unit 1 through a three-point link mechanism 3 that is driven up and down by a lift arm 2.
[0017]
The rotary tiller 4 includes a rotary case 5, a rotary claw 6 that is pivotally supported at the lower portion thereof and is driven to rotate at a high speed in the downcut direction, a rotary cover 7 that covers the rotary portion from above, and a rear end that can swing up and down. A rear cover 8 and the like that are appropriately biased downward are provided, and soil that has been cultivated by the rotary claws 6 and jumped to the rear is received by the rear cover 8 to reduce the pressure.
[0018]
The lift arm 2 is driven up and down by a single-acting hydraulic cylinder 9 installed in the rear part of the tractor main unit 1, and a block diagram of a lifting control device for controlling the operation of the hydraulic cylinder 9 is shown in FIG. Is shown in
[0019]
In FIG. 2, 10 is a controller using a microcomputer, 11 is an electromagnetic control valve for controlling the operation of the hydraulic cylinder 9, 12 is a tilling depth setting device comprising a potentiometer, and 13 is a potentiometer for detecting the vertical swinging posture of the rear cover 8. A cover sensor comprising 14, a lift arm sensor comprising a potentiometer for detecting the angular posture of the lift arm 2, 15 a position setting device for detecting the operating position of the position lever 16, 17 an automatic on / off switch, 18 an up switch, Reference numeral 19 denotes a lowering switch. When the automatic on / off switch 17 is set to “OFF”, the position control mode is set. When the automatic ON / OFF switch 17 is set to “ON”, the automatic tilling control mode is set. . Further, when the up switch 18 is operated one-shot, the up control is preferentially performed up to the upper limit regardless of the control mode, and when the down switch 19 is operated one-shot, the down control is performed according to the selected control mode.
[0020]
Next, the position control mode and the automatic tilling control mode will be described.
[0021]
[Position control]
In this mode, the output value from the position setter 15 is set as the target height of the lift arm 2, and the detected value of the lift arm sensor 14 is balanced with the output value (target value) from the position setter 15. Until then, the electromagnetic control valve 11 is feedback-controlled. Therefore, by operating the position lever 16, the rotary tiller 4 is raised and lowered to a height corresponding to the operation position, and is held at that position.
[0022]
[Automatic tilling control]
In this mode, the electromagnetic control valve 11 is feedback-controlled so that the detected value from the cover sensor 13 is balanced with the output value (target value) from the tilling depth setting device 12, and the basic control flowchart is as follows. It is shown in FIG.
[0023]
Here, the actual detection value from the cover sensor 13 is corrected as follows, the correction detection value is compared with the target value, and a flowchart for calculating the correction value is shown in FIG. Yes.
[0024]
Every time the rotary tiller 4 moves forward a set distance (for example, 5 cm), it is determined in which direction the lift arm 2 is operating from the change of the output value from the lift arm sensor 14 (# 1, # 2). Based on this determination, a correction flag is set (# 3, # 4).
[0025]
Here, in the specification set so that the detection value from the cover sensor 13 becomes smaller as the rear cover 8 is lifted and swung, the correction flag is set when the lift arm is not operating either up or down . The flag value is set to stop (0), and when the control command direction is rising and actually operating in the upward direction, the flag value of the correction flag is set to increase (+1) and the control command direction is downward. When actually operating in the downward direction, the flag value of the correction flag is set to lower (−1). However, when the control command direction and the change direction of the lift arm sensor 14 are different , the flag value of the correction flag is set to (0). The flag value of the correction flag that is set every time the set distance moves forward is sequentially stored in the buffer (# 5). Then, the present correction flag value and the past predetermined number of correction flag values stored and stored are weighted and integrated based on a predetermined arithmetic expression to calculate a cover correction value e (# 6).
[0026]
For example, the correction flag value for the current sampling is F (0), the correction flag value before sampling (previous) is F (1), the correction flag value before sampling (previous times) is F (2), n When the correction flag value before sampling is F (n), the cover correction value e is calculated by the following equation.
e = a × [(F (0) + F (1) + F (2) + F (3)] + F (4) + F (5) + F (6) where a is a weighting coefficient. In this example, Only the current correction flag value and the past correction flag value close thereto are multiplied.
[0027]
According to this, when the actual tilling depth is deeper than the target tilling depth and the raising control is performed, the integrated value of the value obtained by multiplying the stored past correction flag value by the weighting coefficient becomes a positive value, and the corrected detection value Becomes larger than the actual detection value. Therefore, the lift control command is in a neutral stop state in equilibrium with the target value before the actual detection value reaches the target value. Therefore, even if the cover sensor reaches the rising point of the soil, the rising control is not immediately executed based on the actual detection value at that time.
[0028]
[Another embodiment]
The present invention can also be implemented in the following forms.
(1) The movement distance of the airframe is detected by detecting the rotational speed of the axle.
(2) If the weighting coefficient “a” can be changed and adjusted, it is possible to perform a suitable correction according to the state of the field and the traveling speed.
(3) It is also possible to make a suitable correction according to the state of the field and the traveling speed by configuring so that the number of correction flags multiplied by the weighting coefficient a can be adjusted.
(4) Each of the plurality of correction flags may be multiplied by a different value of the weighting coefficient a.
[Brief description of the drawings]
[Fig. 1] Side view of agricultural tractor [Fig. 2] Control block diagram [Fig. 3] Basic flowchart of automatic tilling control [Fig. 4] Flow chart of correction value calculation processing [Explanation of symbols]
1 Tractor machine 4 Rotary tiller 8 Rear cover 12 Plowing depth setting device 13 Cover sensor a Weighting factor

Claims (2)

The rotary cultivator is connected to the rear of the tractor so that it can move up and down, and the swing position of the rear cover that can be moved up and down at the rear of the rotary cultivator is detected by the cover sensor. In the automatic tiller control device for agricultural tractors configured to raise and lower the rotary tiller by feedback control so that the target value set by the tiller setter is balanced,
The actual detection value from the cover sensor is sampled for each set travel distance, and the direction of the lift control command and the actual lift operation direction are both upward directions from the direction of the lift control command and the actual lift operation direction at that time. In this case, the correction flag value set corresponding to the case where the direction of the elevation control command and the actual elevation operation direction are both downward, or the direction of the elevation control command and the actual elevation operation direction are upside down. the stored stored, the stored correction values are calculated by integrating multiplied by weighting factor correcting flag value and correcting flag value of the current past setting number, the actual detection value of the current on the basis of the correction value An automatic plowing depth control device for agricultural tractors, comprising detection value correction means for correcting the detected value to be a control detection value for comparison with the target value. 2. The automatic tiller control device for agricultural tractors according to claim 1 , wherein the correction flag value multiplied by the weighting factor is a correction flag value at the present time and a correction flag value at a time close thereto.

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