JP2539074B2 - Combine height control - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to an elevating actuator for raising and lowering a mowing section with respect to a vehicle body, a height detecting means for detecting the height of the mowing section, and its height. A height control of the combine, which is provided with a control means for controlling the lifting actuator so that the height of the reaper is maintained at the target height based on a deviation between the detection height of the detection means and the target height. Regarding the device.

[Prior Art] Conventionally, the lifting actuator has been controlled based only on the deviation between the detection height of the height detection means and the target height. That is, the operating speed of the lifting actuator is adjusted to be large when the deviation is large and small when the deviation is small.

Specifically, PI, PID control, or the like is adopted as the control based on the deviation. For example, in the PID control, the deviation and the control gain corresponding thereto are used to calculate the proportional element, the integral element, and the differential element, and the operation results of the lifting actuator are simply added. It seeks quantity.

[Problems to be Solved by the Invention]

In the above-mentioned conventional technology, it is difficult to achieve both high-speed response and stability, and there is a risk that the cutting height of the grain culm may be uneven.

In addition, in this type of combine height control device, the detection height of the height detection means may fluctuate momentarily due to unevenness of the ground, etc. To increase the control gain,
Although the responsiveness can be improved, there is a risk that overshoot or hunting will occur and the stability will deteriorate.

An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art and to obtain a height control device having excellent responsiveness and stability and capable of improving combine harvesting performance.

[Means for solving the problem]

In order to achieve this object, a first characteristic configuration of a combine height control device according to the present invention is provided with a differential operation means for obtaining a temporal change amount of the deviation, and the control means is provided with the deviation and It is configured to operate the lifting actuator based on an operation amount that is fuzzy inferred by using a variation amount of the deviation with time.

A second characteristic configuration is provided with a storage unit that presets and stores the operation amount, and the control unit accesses the operation amount corresponding to the deviation and the temporal change amount from the storage unit. It is configured.

[Work]

 The operation of the first characteristic configuration is as follows.

In the fuzzy reasoning, for example, it is easy to increase the control gain when the deviation is large and decrease the control gain when the deviation is small. Further, from the viewpoint of safety, it is possible to increase the control gain on the ascending / descending side and decrease the control gain on the descending side in order to suppress the ground height of the cutting unit from becoming lower than the target height as much as possible.

Further, by using the amount of temporal change as a fuzzy variable, it becomes possible to control while predicting a change in cutting height. For example, when the mowing unit is being lowered, even if the deviation is the same, if the time variation of the deviation is large, the descending speed of the lifting actuator is higher than that when the time variation is small. It is possible to control the reaper so as to prevent the reaper from accidentally coming into contact with the ground.

In the second characteristic configuration, since the operation amount at that time is obtained by referring to the stored information in the storage means, it is not necessary to perform the inference operation.

〔The invention's effect〕

In the first characteristic configuration, both reactivity and stability are excellent,
Moreover, it is possible to obtain a combine height control device with high safety.

In the second characteristic configuration, since the operation amount can be obtained without performing inference calculation, the response speed of the combine height control device can be further increased.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 6, the combine includes a vehicle body (V) provided with a pair of left and right crawler type traveling devices (1), and a reaping section (2) movably connected to the front portion thereof. There is. The reaping section (2) can be moved up and down by a single-acting hydraulic cylinder (3) as an actuator for lifting.

Further, the cutting unit (2) has a height detecting sensor (4) as a height detecting means using a reflection type ultrasonic sensor.
And a height detecting sensor (4) as described later.
It is configured to be able to maintain the target ground height (Hs) that is automatically set based on the detection information of. However, the mowing part (2) can be raised and lowered by manual operation.

The ascending / descending speed can be varied by changing the flow rate of the hydraulic oil to the ascending / descending hydraulic cylinder (3).

Explaining the hydraulic circuit for the hydraulic cylinder (3), as shown in FIG. 1, it is possible to switch between two states, that is, a state in which the pressure oil flows toward the hydraulic cylinder and a state in which the discharge of the pressure oil is stopped. for opening and closing the electromagnetic-operated raising control valve (5), the oil passage toward its raised control valve (5) the hydraulic cylinder (3) from the connected drain oil path (r ₁₎ (r ₂₎ An electromagnetically operated lowering control valve (6) is provided.

Then, the target height setting device (9) using the potentiometer, the raising / lowering operation lever (10) for manual raising / lowering, and the detection information of the height detecting sensor (4) and the information of the raising / lowering operation lever (10) are used. On the basis of the quantity control valve (5),
Each of the control devices (12) using a microcomputer for controlling the operation of (6) is provided. In the figure, (1
3) is the height detection sensor (4) for the mowing part (2)
Is a changeover switch for switching between an automatic lifting operation based on the detection information of the above or a lifting operation based on the operating state of the lifting operation lever (10), , The automatic mode for automatically moving up and down is instructed in the ON state, and the manual mode for manually moving up and down in the OFF state is instructed.

Next, a configuration for adjusting the operation of the hydraulic cylinder (3) in the automatic mode will be described.

In the control device (12), the detected height (Hx) and the target height (H
The time variation (dek) of the deviation (ek) from s) is calculated by the following formula.

dek = k ₁ · (ek−ek _−n ) (1) where ek is the deviation at that time, ek _−n is the deviation before a predetermined time, and K ₁ is a coefficient. The detected height (Hx) is the reception time until the ultrasonic wave is projected and the reflected wave is received, and the target height (Hs) is the target reception time.

Then, the deviation (ek) and the temporal change amount (dek)
The operation amounts of the hydraulic cylinder (3) corresponding to and are set in the table in advance. In the present embodiment, the deviation (e
k) and the temporal change amount (dek) are quantized in units of 1 μsec to create the above table, but the unit of quantization can be variously changed.

By the way, in the automatic mode, the up-and-down speed of the hydraulic cylinder (3) is adjusted by changing the duty ratio of the pulse width modulation signal for driving the solenoid of the lowering control valve (6).

That is, when raising the mowing part (2), the raising control valve (5) is opened, and when lowering the raising control valve (5), the raising control valve (5) is kept closed. By changing the duty ratio, the lifting speed of the hydraulic cylinder (3) can be adjusted.

That is, the opening / closing of the raising control valve (5) and the duty ratio correspond to the operation amount of the hydraulic cylinder (3).

Then, as shown in FIG. 5, there are 31 patterns in the operation amount, and patterns corresponding to the deviation (ek) and the temporal change amount (dek) are stored in a table (not shown) in advance. It is set.

Therefore, the control device (12) controls the operation of the hydraulic cylinder (3) while accessing the operation amount corresponding to the deviation (ek) and the temporal change amount (dek) from the table.

That is, the control device (12) is used to configure each of the differential operation means (101), the storage means (102), and the control means (100).

The table is created as a result of an inference operation using the deviation (ek) and the temporal change amount (dek) as fuzzy variables.

Figure 2 shows the control rules for fuzzy reasoning. Also,
Fig. 3 shows the deviation (e
k) and the membership function with respect to the temporal variation (dek) are shown. The horizontal axis of FIG. 3 indicates the deviation between the ultrasonic reception time of the height detection sensor (4) and the target reception time for the deviation (ek), and the time variation (dek) for the deviation (ek) described above (1). ) Indicates the value obtained by the equation. Furthermore, in FIG.
The membership function of the consequent part of the control rule is shown.

The procedure for creating the table will be described with reference to FIGS. 3 to 5.

(I) The smaller one of the membership value (μi) of the deviation (ek) and the membership value (μj) of the temporal change amount (dek) is set as the fitness (fij) of the control rule. That is, the fitness (fij) is obtained by the following equation.

fij = μi ∧μj (ii) The membership function (ΔW) of the consequent part is horizontally cut at the height of the fitness (fij) to obtain the trapezoidal membership function (ΔW ′) (in the figure, shaded). Shown).

(Iii) The membership functions (ΔW ′) obtained from the respective control rules are integrated to obtain the coordinate point (u ₀ ) of the center of gravity thereof.

(Iv) The pattern number is obtained by rounding the coordinate point (u ₀ ) and converting it into an integer.

(V) The table can be created by performing the above procedure for each quantization unit of the deviation (ek) and the temporal change amount (dek).

[Another embodiment]

In the above embodiment, the operation amount of the hydraulic cylinder (3) is made into a table in advance, and the operation amount corresponding to the deviation (ek) and the temporal change amount (dek) is accessed from the table. However, the hydraulic cylinder (3) may be controlled.

Further, the specific configuration of each part such as using an electric motor as the lifting actuator (3) can be changed in various ways.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

The drawings show an embodiment of a combine height control device according to the present invention. FIG. 1 is a block diagram of a control configuration, FIGS. 2 to 4 are explanatory views of control rules, and FIG. 5 is an operation of a hydraulic cylinder. FIG. 6 is a front side view of the combine, illustrating the amount. (2) …… Mowing unit, (3) …… Elevating actuator,
(4) …… Height detection means, (100) …… Control means, (10
1) …… Differential calculation means, (102) …… Storage means, (Hx)…
… Detected height, (Hs) …… target height, (ek) …… deviation,
(Dek) …… Amount of change over time, (V) …… Body.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kenichi Mae, 64 Ishizukita-machi, Sakai City, Osaka Prefecture Kubota Sakai Factory Co., Ltd. (72) Hironori Shimizu 64, Ishizukita-machi, Sakai City, Osaka Prefecture Kubota Sakai Manufacturing Co., Ltd. In-house (56) References JP 64-47309 (JP, A) JP 64-23810 (JP, A)

Claims (2)

(57) [Claims] 1. An elevating actuator (3) for raising and lowering a reaping section (2) with respect to a vehicle body (V), height detection means (4) for detecting the height of the reaping section (2), and the same. Based on the deviation (ek) between the detected height (Hx) of the height detecting means (4) and the target height (Hs), the height of the reaper (2) is maintained at the target height (Hs). And a control means (100) for controlling the ascending / descending actuator (3) so as to control the height of the combine, and a differential operation for obtaining a temporal change amount (dek) of the deviation (ek). Means (101) is provided, and the control means (100) is configured to control the deviation (ek) and the time variation (de) of the deviation (ek).
k) and a height control device of the combine configured to operate the lifting actuator (3) based on a fuzzy inferred operation amount. 2. A storage means (102) for preset setting and storing the operation amount is provided, and the control means (100) controls the operation corresponding to the deviation (ek) and the temporal change amount (dek). The combine height control device of claim 1, wherein the height control device is configured to access a quantity from the storage means (102).