JPH0494601A - Depth control of working machine against ground - Google Patents

Abstract

PURPOSE:To carry out stabilized depth control by dividing difference between a detection value by a depth sensor and set value of tilling depth setter into three stages and changing turn-on time of solenoid. CONSTITUTION:Difference between a detection value by a depth sensor 15 and set value of a tilling depth setter 18 is compared and in an area in which the difference is minute and area in which the difference is slightly large, a solenoid is driven in each different and definite turn-on time and in an area in which the difference is large, turn-on time is changed according to the difference to carry out depth control.

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a depth control device for a ground work machine connected to a power agricultural machine such as a tractor, and particularly relates to a depth control device for controlling the on-time of a pulse for turning on and off a solenoid. are classified based on the difference between the detected value of the depth sensor and the set plowing depth,
The present invention relates to depth control of ground-based working machines, each of which is controlled at predetermined on-times.

[Prior Art] Conventionally, depth control of this type of ground work machine involves installing a depth sensor that detects the plowing depth of the ground work machine, and comparing the value detected by this depth sensor with the value set by a plowing depth setting device to determine the difference. The on-time during one pulse that turns on and off the solenoid of the lift control valve is changed according to the

For example, if the wheels of a power agricultural machine such as a tractor fall into a groove during depth control, and the ground work equipment suddenly rises or falls, the elevation control valve should be adjusted in order to escape from such a situation as quickly as possible. Hydraulic control is performed on-time at a speed close to maximum capacity.

[Problem to be solved by the invention] In conventional depth control, when the difference between the detection value of the depth sensor and the plowing depth set value is extremely large, the solenoid is activated at an on-time specified according to the difference. You can turn it on and off. However, if the difference between the detected value of the depth sensor and the plowing depth set value becomes small, the plowing work is being carried out smoothly and the plowing depth is changing gradually. Frequent changes will disturb the well-finished surface.

Therefore, regardless of the magnitude of the difference between the detected value of the depth sensor and the plowing depth set value, a technical problem arises that must be solved in order to perform stable depth control, and the present invention solves this problem. The purpose is to

[Means for Solving the Problems] The present invention has been proposed to achieve the above object, and is a ground-based work machine that is provided so as to be able to be raised and lowered by a hydraulic lifting mechanism, and which is capable of being used for cultivation. Equipped with a depth sensor that detects depth, the elevating control is performed by changing the on time during one pulse for turning on and off the solenoid of the elevating control valve according to the difference between the detected value by the depth sensor and the value set by the plowing depth setting device. In those that control the operation of valves,
In the first correction band where the difference between the detection value of the depth sensor and the plowing depth set value is small, the on-time is set to a constant value, and
In the second correction band where the difference is slightly larger than the first correction band, the on-time is set to a constant value that is slightly larger than the on-time of the first correction band, and further, the difference exceeds the second correction band. In the third correction band, the on-time is changed in accordance with the difference to control the operation of the elevation control valve.

[Operation] This invention detects the plowing depth of the work implement using a depth sensor, constantly compares the difference between the detected value and the set value of the plowing depth setting device, and changes the on-time by dividing the difference into three stages. . In the first correction band where the difference is small and the second correction band where the difference is slightly larger, the operation of the elevation control valve is controlled at different constant on-times.

Then, in a third correction band where the difference exceeds the second correction band, depth control is performed by changing the on-time according to the difference. That is, when the difference is small, the on-time changes in two to three steps, so that stable control operations can be performed.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the accompanying drawings. In Figure 1, (1) is a tractor, which is a powered agricultural machine.
(2) is a rotary ground work machine, (3) is a top link, (4) is a lower link, (5) is a lift arm,
(6) is a lift cylinder for horizontal control, and (7) is a horizontal stroke sensor. Further, (8) is a mast, and (9) is a support plate that connects the rotary main body (2) and the top link (3). The rear part of the rotary main body (21) and the support plate (9) are connected via an attitude control cylinder OΦ, and an attitude stroke sensor 00 is disposed parallel to this attitude control cylinder OΦ. In addition, a lift arm angle sensor (2) is provided at the rotation base of the lift arm (5), and a slope sensor is installed at the bottom of the seat to detect horizontal inclination. In addition, a rear cover (depth sensor θ) is installed to control the plowing depth.

Each of the sensors is controlled by a control device θ provided on the tractor (1).
The control device θQ includes a position lever (r7) that adjusts the height of the ground work equipment, a plowing depth setting device (g) that adjusts the plowing depth of the o-tary, and a plowing depth setting device (g) that adjusts the tilt of the rotary. Various switches are provided, such as an inclination setter (g) for changing the reading sensitivity of the depth sensor, and a sensitivity switch (1) for changing the reading sensitivity of the depth sensor. Further, the lift arm (5) rotates in the vertical direction by the expansion and contraction of a lift cylinder (not shown), and constitutes a hydraulic lifting mechanism f20, and this lift cylinder is hydraulically controlled by an lifting control valve. . still,
The symbol (g) is a horizontal control valve.

Next, the depth control of the present invention will be explained according to the block diagram of FIG. 2 and the flowchart of FIG. 3. First, read the detected value of the depth sensor 0 → and the position of the tilling depth setter (peak and each switch (step l-01), and after confirming that tilling depth control is in progress (step +02), set the tilling depth setting value. The difference between the detected value of depth sensor θ→ (αn
) is calculated and divided into a first modified band, a second modified band, and a third modified band, and the on-time (Tan) is determined according to each band (step l03).

That is, the first correction band is set when the difference (αn) is small and less than 50, and the on-time at this time is set to a constant value for both the rising output and the falling output. Also, the difference (αn)
is slightly wider than the first correction band and is 50 mm or more15
When it is less than 0III11, it is a second correction band,
At this time, the on time is the first for both the rising output and the falling output.
Set to a constant value slightly larger than the on-time of the correction band.

Furthermore, if the difference (αn) exceeds the second correction band and is 150
mm or more is defined as a third correction band, and in this case, the on-time is changed according to the difference and the optimum on-time is selected.

Next, when the plowing depth set value and the detected value of the depth sensor match and the difference (αn) is neutral (step l0
It is assumed that the output is within the 4L dead zone and the output is turned off (step 401), and the correction counter is reset (step 402). If the difference (αn) is less than 50 mm, continue the first correction band and proceed from step 105 to step 106; if the difference (αn) is 50 mm or more and less than 150 mm, continue the second correction band and proceed to step 106. 205 to 206
Further, if the difference (αn) is 50 states or more per month, the correction counter is reset (step 301), and the process advances to step 302.

In step 106 or 206, it is determined whether it is the second pulse or later from the start of the specified on-time output, and if it is the second pulse or later, the current lift arm value LFn is stored (step 107 or 207). Then, in step 10, it is determined whether or not the lift arm value from the previous time is remembered.
8 or 208L The difference between the lift arm values from the previous time and this time is calculated (step 109 or 209).

Then, it is determined whether the difference in the lift arm values is within the reference range of the first correction band or the reference range of the second correction band (step 110 or 210''), and the difference is smaller than the reference. If so, add 1 to the correction counter in step I.
If the difference is larger than the II or 2+1L standard, 1 is subtracted from the correction counter (step 112 or 212). This correction counter is counted in step 113 or 2+3, and when it reaches +IO, it does not increase any further and the correction counter value is limited to +IO (step 114 or 2I4).
). On the other hand, when it reaches -10, it will not be subtracted below, and the correction counter value will be limited to -10 (step +1
5 or 215).

Then, the corrected karatsuta value is added to the corrected base on time (t
o) to calculate the correction value (tn).Step 116
or 216), in response to an output request for ascending or descending (step 302), when there is an output request for ascending, set the on time to Ton+tn to output ascending to the ascending/descending control valve (2); step 303); When there is an output request, the on-time is set to Ton + tn to raise and lower the control valve (2)
(Step 304) On the other hand, during rough raising or shallow raising, the finished surface tends to be rough, and at that time, the puller cover (B) changes greatly.
If depth control is performed by changing the on-time as described above in response to this change, a so-called undulating phenomenon will occur. In such a case, the sensitivity switch (a) may be manually switched to the insensitive side, but the sensitivity may also be switched automatically as shown in the flowchart of FIG.

First, in the same manner as described above, the detected value of the depth sensor (()) and the position of each switch are read (step 501), and in steps 502 and 503, the plowing depth set value and the depth sensor (
The difference (αn) from the detected value of the seagull is calculated. Then, check the position of the sensitivity switch (1) (step 504), set the gain coefficient to 1.0 based on when the sensitivity switch (a) is on the manual sensitive side (step 505), and check the position of the sensitivity switch (4). When it is on the insensitive side of manual, set the gain coefficient to 0.
．． 5 (step 506) and widens the dead zone by +1 bit (step 507).

When the sensitivity switch (A) is located on the automatic side, it is determined whether the difference (αn) is within ±15011QI (step 601), and the current difference is compared to the previous difference (α.-8). When the difference (αn) is in the opposite direction and is greater than ±150 mm, the process proceeds from step 602 to 603, and when the difference (αn) is within ±150 mm, the process proceeds to step 7.3. In step 603 or 703, it is confirmed whether the sensitivity switch (to) is on the automatic sensitive side or on the insensitive side, and in step 603, the gain coefficient is set to 0°7 on the sensitive side (step 604) and 0.5 on the insensitive side. (Step 6
05) to suppress the sensitivity and widen the dead zone by +1 bit (step 606 or 607). On the other hand, in step 703, the gain coefficient is set to 1.2 on the sensitive side (step 7
04), the sensitivity is set to 0.8 (step 705) on the insensitive side.

After setting different gain coefficients under each condition, the difference (αn) is multiplied by the gain coefficient to obtain the deviation (An).
is calculated (step 60B), and when this deviation (An) is neutral, the output is turned off (step 60).
9 to 610), if the deviation (An) is less than 50 mn (step 801), the on-time is set to a constant value at less than 50+nm (step 802). If the deviation (An) is 50mm or more and less than 150Il1m (Step 9
Step 902) Set the on-time to a constant value between 0+) 50 and 150 mm, and the deviation (A n) is 150 mm.
If it is above, the on-time is changed according to the difference and the optimum on-time is selected (step 903).

Furthermore, in response to a rising or falling output request (step 80
3) When there is a request for a rise output, the rise output is output to the lift control valve (A) at the ON time selected in each step described above (step 804), and when there is a fall output request, the rise output is output to the ON time selected in each step described above. A downward output is made to the elevation control valve (g) at the time (step 805). Then, after clearing the addition of the dead zone (step 8D6), step 501
Return to

In this way, by multiplying the difference (αn) by a different gain coefficient, the sensitivity can be automatically switched, and the sensitivity on the automatic insensitive side and the dull side on the sensitive side overlap, allowing fine control. can be done.

Note that this invention can be modified in various ways without departing from the spirit of the invention, and it goes without saying that this invention extends to such modifications.

[Effects of the Invention] As detailed in the above embodiment, the present invention divides the difference between the detected value of the depth sensor and the setting value of the plowing depth setting device into three stages, and divides the difference between the detected value of the depth sensor and the set value of the plowing depth setting device into three stages, and The second correction band sets the on-time to a predetermined constant value. Therefore,
The plowing depth does not change suddenly (and the finished surface can be formed smoothly. Also, since the on-time selection range is small, the size of the control program is compact.

In this way, it becomes possible to perform stable depth control regardless of the magnitude of the difference.

[Brief explanation of drawings]

The figures show one embodiment of the present invention, in which Fig. 1 is a side view of a rotary crane connected to a ground work machine, Fig. 2 is a block diagram,
3 and 4 are flowcharts. (1)・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ Depth sensor・Rotary (1G...Control device G!0...Hydraulic lifting mechanism

Claims (1)

[Claims] A ground work machine that can be raised and lowered by a hydraulic lifting mechanism, and is equipped with a depth sensor that detects the plowing depth of the work machine, and the plowing depth is adjusted according to the difference between the detected value by the depth sensor and the set value by the plowing depth setting device. In a device that controls the operation of the lift control valve by changing the on-time during one pulse that turns on and off the solenoid of the lift control valve, the difference between the detection value of the depth sensor and the plowing depth setting value is small. In a certain first correction band, the on-time is set to a constant value, and in a second correction band where the difference is slightly larger than that of the first correction band, the on-time is set to be slightly larger than the on-time of the first correction band. The on-time is set to a constant value, and furthermore, in a third correction band where the difference exceeds the second correction band, the on-time is changed according to the difference to control the operation of the elevation control valve. Depth control of ground-based work equipment.