JPH05240332A - Tractor speed change control device - Google Patents

Abstract

PURPOSE:To enable the speed change operation with a feeling close to the human operation by implementing the fuzzy inference based on the deflection of the speed between the input side and the output side of a transmission device and the change amount in this deflection, and determining the shift position or the clutch hydraulic pressure of the transmission device. CONSTITUTION:A speed control device consists of a forward/backward switching device 3 which receives the power of an engine 1 through a main clutch 2, and a main and a sub transmission 4, 5. The output signals of rotation sensors 30-32, to detect the speed of the respective shafts which are arranged in series, of stroke sensors 33-36 to detect the movement amount of a shifter of the main and the sub transmission device 4, 5, or the like are received by a controller 38, and the respective hydraulic pressure valves 19, 20-23 for the hydraulic cylinders 24-27 for shifter operation are controlled by the control signals which are calculated by the controller. That means, the deflection between the detected values of the rotation sensors 30, 31, and the changes in this deflection are calculated by the controller 38, and the control signal is generated by implementing the fuzzy inference by setting the deflection and the change amount in the deflection as a conditional part membership function.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for electronically controlling a shift operation of a tractor.

[0002]

2. Description of the Related Art A tractor equipped with an electronically controlled gear shift control device, which selects a gear shift according to changes in engine output due to work and automatically performs clutch on / off operation and gear change operation, has been developed. Being developed.

[0003]

However, in the above-mentioned conventional automatic transmission tractor, the shift position is uniformly controlled so as to shift down when the engine load is above a certain level and shift up when the engine load is below a certain level. As a result, I often had to repeatedly upshift and downshift while driving, and there was a problem with riding comfort. Also,
Since the operating force for engaging and engaging the clutch was always constant regardless of the degree of load, the clutch could sometimes lack smoothness in engaging.

[0004]

In order to solve the above problems, the present invention has the following constitution. That is, a shift control device for an agricultural work machine according to the present invention is a shift control device for a tractor that includes a hydraulically controlled clutch that transmits rotational power from an engine-side shaft to a transmission-side shaft. The first rotation speed detecting means for detecting the rotation speed of the transmission, the second rotation speed detecting means for detecting the rotation speed of the shaft on the transmission side, and the deviation between the detection values of the first and second rotation speed detecting means. Deviation calculating means for calculating, change amount calculating means for calculating a change amount of the deviation, fuzzy inference using the deviation and the change amount as a condition part membership function,
And a determining unit that determines the shift position of the transmission or the hydraulic pressure for operating the clutch.

[0005]

The rotation speed of the shaft on the engine side is detected by the first rotation speed detecting means, and the rotation speed of the shaft on the transmission side is detected by the second rotation speed detecting means. Then, the deviation of the detection values of the first and second rotational speed detecting means is calculated by the deviation calculating means, and the change amount of the deviation is calculated by the change amount calculating means. The deviation and the amount of change in the deviation thus obtained are used as a conditional part membership function to perform fuzzy inference by the determining means to determine the shift position of the transmission or the hydraulic pressure for operating the clutch.

When the shift position of the transmission and the hydraulic pressure for operating the clutch are determined based on the fuzzy reasoning, the shift change and the clutch connection speed can be adjusted in consideration of the expected load fluctuation. The shift operation can be performed with a feeling similar to that of, and the riding comfort is improved.

[0007]

1 is a transmission system diagram of a tractor which is an example of the present invention. In the figure, 1 is an engine, 2 is a main clutch, 3 is a forward / reverse switching device, 4 is a main transmission device, 5 is a sub transmission device, 6 is a front wheel, 7 is a rear wheel, and the symbols with S respectively rotate. The symbols bearing the shaft and G respectively represent gears. The rotation output of the engine 1 is separated into a traveling output and a PTO output after passing through the main clutch 2. The traveling output is appropriately switched between the forward speed and the reverse speed by the forward / reverse switching device 3, and is shifted by the main transmission device 4 and the auxiliary transmission device 5 and transmitted to the front wheels 6.6 and the rear wheels 7, 7, respectively.

The forward / reverse switching device 3 is constructed to be operated by hydraulic pressure, and connects the shaft S4 and the gear G3 to each other to connect the gears G2 and G2.
When the power is transmitted from the shaft S3 to the shaft S4 via G3, the forward speed is obtained, and when the shaft S4 and the gear G6 are connected to each other and the power is transmitted from the shaft S3 to the shaft S4 through the gears G4, G5 and G6, the reverse speed is obtained, and the shaft S4 is rotated by the gear. The transmission from the shaft S3 to the shaft S4 is cut off by not connecting any of G3 and G6. That is, the forward / reverse switching device 3 has a role of switching between forward and reverse, and a role of a clutch when shifting the main transmission 4 and the sub transmission 5 described later.

When the main transmission 4 is transmitted from the shaft S4 to the shaft S5 via the gears G7 and G8, it is in the first speed and the gears G9 and G10.
Transmission from shaft S4 to shaft S5 via the 2nd speed, gear G1
1, when the power is transmitted from the shaft S4 to the shaft S5 via G12, 3
From the shaft S4 to the shaft S via the gears G13 and G14
When it is transmitted to 5, it becomes 4th speed. In addition, 1st speed, 2nd speed, 3rd speed,
The transmission ratio increases in the order of 4th speed. These shift operations are performed by the shifters 10 and 11.

The sub-transmission 5 has a high speed transmission when the shaft S5 and the shaft S6 are directly connected, and G15, G16, S among the gears and the shafts.
Transmission from shaft S5 to shaft S6 via G6, G17, and G18 causes medium-speed transmission, and among gears and shafts G15, G19, and S
When the power is transmitted from the shaft S5 to the shaft S6 via 8, G20, G21 and S9, low speed power transmission, G15 and G1 among gears and shafts are transmitted.
9, S8, G20, G21, S9, G22, G23, S
Transmission from shaft S5 to shaft S6 via 7, G17, G18 results in ultra-low speed transmission. These shift operations are performed by the shifter 1
Perform at 2 and 13.

FIG. 2 shows a main part of the hydraulic circuit diagram of the tractor. The oil delivered from the pump 15 is divided into two directions by the flow dividing valve 16, and the oil in one direction is divided into the boost control valve 17
Is supplied to the switching valve 18 for switching and driving the hydraulic switching device 3, and the oil in the other direction is supplied to the switching valves 20, 21, 22, 23 for switching and driving the main transmission device 4 and the auxiliary transmission device 5. .. In the figure, 24 and 25 are hydraulic cylinders for operating the shifters 10 and 11 of the main transmission 4. The switching valves 22 and 23 of the sub transmission 5 are also the switching valves 2 of the main transmission.
It has the same structure as 0, 21 and is followed by shifters 12, 1
Hydraulic cylinders (not shown) 26 and 27 for operating 3 are connected.

The shift control system of this tractor is schematically shown in FIG. That is, the rotation sensors 30, 31, 32 detect the rotation speeds of the shafts S2, S4, S6, respectively. The shaft S2 is a shaft on the engine side with respect to the forward / reverse switching device (hydraulic clutch) 3, and the rotation sensor 30 for detecting the rotation speed of this shaft is used as a first rotation speed detecting means. Also, the axis S
4 is a shaft on the transmission side with respect to the forward / reverse switching device 3,
The rotation sensor 31 that detects the rotation speed of this shaft is referred to as second rotation speed detection means. Furthermore, the shifter 1 of the main and auxiliary transmissions
The amount of movement of 0, 11, 12, 13 is also calculated by the stroke sensor 3
3, 34, 35, 36 are detected. The controller 38 processes the detection results of these sensors and the setting command given from the operation unit 37, and the hydraulic valves 18, 2 for controlling the forward / reverse switching device 3, the main transmission device 4, and the auxiliary transmission device 5.
Output commands are issued to 0, 21, 22, 23. This is shown in a block diagram as shown in FIG.

Regarding the shift control, the first is to adjust the hydraulic pressure for operating the forward / reverse switching device 3 which is a hydraulic clutch.
And the second control for determining the shift positions of the main transmission 4 and the sub transmission 5. Both controls will be described below.

First, for the first control, the detection value R _{1 of} the first rotation speed detection means (rotation sensor) 30 and the detection result R ₂ of the second rotation speed detection means (rotation sensor) 31 are compared,
The deviation D (= R ₁ −R ₂ ) between the _two is calculated. Further, the change amount ΔD of the deviation D is calculated. And these deviations D
Fuzzy inference is performed with the change amount ΔD as an input variable (conditional part membership function) and the opening degree correction amount C of the hydraulic valve 18 as an output variable.

When performing fuzzy inference, the fuzzy control rules shown in Table 1 are adopted. The horizontal arrangement is the deviation D, the vertical arrangement is the change amount ΔD, and the valve opening correction amount C is shown in the table.
And Where NB is negative and large, NM is negative and medium,
NS is negative and small, Z0 is zero, PS is positive and small, P
M means positive and medium, and PB means positive and large. Regarding the valve opening correction amount C, the clutch is engaged at a faster speed toward PB, and the clutch is engaged more slowly toward NB with reference to Z0.

[0016]

[Table 1]

The meaning of Table 1 will be described in words as follows.

Regarding the 1st row and 1st column, "if the engine-side shaft rotational speed is lower than the transmission-side shaft rotational speed (NB), and the difference fluctuates in the negative direction. (N
If B), increase the valve opening (PB). "That's what it means. If the time chart of the deviation D is as shown in FIG.
This corresponds to the part, and both rotational speeds R ₁ and R ₂ change as shown in FIG. Although it rarely occurs in actuality, it is the case where the vehicle is accelerating due to inertia on a downhill or the like. When engaging the clutch in such a case, there is no concern that the load will suddenly increase, so the clutch should be engaged all at once. When the clutch is engaged, both rotational speeds R ₁ and R ₂ become the same, and after that, engine speed R ₁ (= R
₂ ) decreases.

Regarding the 1st row and the 7th column, "If the rotation speed of the shaft on the engine side is smaller than the rotation speed of the shaft on the transmission side (NB), and the difference fluctuates in the positive direction. (P
If it is B), do not change the valve opening (Z0). "That's what it means. Corresponding to part B in FIG. 5, both rotational speeds R
₁ and R ₂ are as shown in FIG. The engine is idling and the tractor body is coasting. When engaging the clutch in such a case, the clutch may be engaged at the standard speed.

Regarding the 7th row and 1st column, "if the engine-side shaft rotational speed is higher than the transmission-side shaft rotational speed (PB), and the difference fluctuates in the negative direction. (N
If it is B), do not change the valve opening (Z0). ". Corresponding to part C in FIG. 5, both rotational speeds R
₁ and R ₂ are as shown in FIG. For example, when the accelerator is stepped on while traveling. Also in this case, the clutch may be engaged at the standard speed.

Regarding 7th row and 7th column, "if the engine-side shaft rotational speed is higher than the transmission-side shaft rotational speed (PB), and the difference fluctuates in the positive direction. If it is (PB), increase the valve opening (PB). "
That's what it means. This corresponds to the portion D in FIG. 5, and both rotational speeds R ₁ and R ₂ are as shown in FIG. Tractor When the clutch is connected while the main machine is stopped, the clutch is slowly engaged so that rotational power can be smoothly transmitted from the engine side shaft to the transmission side shaft.

The deviation D of the rotational speeds, the variation ΔD thereof and the valve opening correction amount C are classified according to their magnitudes as shown in FIGS. 10 to 12, and are represented as a membership function.

Assuming that the deviation D is d and the change amount ΔD is Δd, the valve opening correction amount C in this case is determined (see FIG. 13). The membership value of the deviation D at this time is a ₁ given by Z0 and a ₂ given by PS, and the membership value of the variation ΔD is PS
B ₁ given by PM and b ₂ given by PM.
The membership region U of the valve opening correction amount C is obtained according to the fuzzy rule, and the center of gravity position of this region in the horizontal axis direction is set as the correction amount C.

Next, in the second control, the deviation D between the rotational speeds R ₁ and R ₂ and the variation ΔD thereof are calculated as in the case of the first control, and the deviation D and the variation ΔD thereof are input. Fuzzy inference is performed using the variable (conditional part membership function) and the shift change amount C as output variables.

When performing fuzzy inference, the fuzzy control rules shown in Table 2 are adopted. The horizontal arrangement is the deviation D, the vertical arrangement is the change amount ΔD, and the shift change amount O is in the table. Regarding the shift change amount C, positively, the speed is increased,
Negative means deceleration.

[0026]

[Table 2]

As in the case of control 1, the meaning of Table 2 will be described in words as follows.

Regarding the 1st row and 1st column, "if the actual engine speed is smaller than the set engine speed (N
B) and the difference fluctuates in the negative direction (NB)
Then shift up (PB). "That's what it means. This corresponds to the portion C in FIG. 5 above, when the load is rapidly lightening, and the speed is increased quickly.

Regarding the 1st row and 7th column, "if the actual engine speed is smaller than the set engine speed (N
B), and the difference fluctuates in the positive direction (PB)
If so, do not change gears (Z0). "That's what it means. This corresponds to the portion D in FIG. 5, which is when the load is light at the present time but starts to be applied rapidly, and the subsequent load fluctuation is estimated to prevent an extra shift change.

Regarding 7th row and 1st column, "If the actual engine speed is higher than the set engine speed (P
B) and the difference fluctuates in the negative direction (NB)
If so, do not change gears (Z0). "That's what it means. This corresponds to the portion B in FIG. 5, where the load at the present time is large but the load is rapidly lightening, and in this case as well, the shift change is not made by estimating the subsequent load fluctuation.

Regarding 7th row and 7th column, "if the actual engine speed is higher than the set engine speed (P
B), and the difference fluctuates in the positive direction (PB)
Then shift down (NB). "That's what it means. This corresponds to the portion A in FIG. 5, where the load at the present time is large and the load is further increasing, and the speed is quickly reduced to reduce the load.

Membership function D, Δ of the second control
D and O are represented as shown in FIGS.
17 shows an example of how to obtain the shift change amount C.

[0033]

As described above, the tractor speed change control device according to the present invention performs a speed change operation close to a human operation feeling according to the running condition of the tractor body, the field condition, the working condition, and the like. Not only can unnecessary shift changes be eliminated, but the clutch can be operated smoothly, which improves ride comfort.

[Brief description of drawings]

FIG. 1 is a transmission system diagram of a tractor which is an example of the present invention.

FIG. 2 is a diagram showing a main part of a hydraulic circuit of the tractor shown in FIG.

FIG. 3 is a diagram schematically showing a shift control device.

FIG. 4 is a block diagram of a shift control device.

FIG. 5 is a time chart of the deviation between the rotation speed of the engine-side shaft and the rotation speed of the transmission-side shaft.

FIG. 6 is a time chart of the rotation speed of the engine-side shaft and the rotation speed of the transmission-side shaft.

FIG. 7 is a time chart of the rotation speed of the engine-side shaft and the rotation speed of the transmission-side shaft.

FIG. 8 is a time chart of the rotation speed of the engine-side shaft and the rotation speed of the transmission-side shaft.

FIG. 9 is a time chart of the rotation speed of the engine-side shaft and the rotation speed of the transmission-side shaft.

FIG. 10 is a diagram showing a membership function of a deviation between an engine-side shaft rotational speed and a transmission-side shaft rotational speed in control 1;

FIG. 11 is a diagram showing a membership function of the amount of change in the deviation between the rotational speed of the engine-side shaft and the rotational speed of the transmission-side shaft in control 1;

FIG. 12 is a diagram showing a membership function of a valve opening correction amount in control 1.

FIG. 13 is a diagram showing an example of how to obtain a valve opening correction amount in control 1.

FIG. 14 is a diagram showing a membership function of a deviation between an engine-side shaft rotational speed and a transmission-side shaft rotational speed in control 2;

FIG. 15 is a diagram showing a membership function of the amount of change in the deviation between the rotational speed of the engine-side shaft and the rotational speed of the transmission-side shaft in control 2;

16 is a diagram showing a membership function of a shift change amount in control 2. FIG.

FIG. 17 is a diagram showing an example of how to obtain a shift change amount in control 2.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 engine 3 forward / reverse switching device (clutch) 4 main transmission device 5 auxiliary transmission device 30 rotation sensor (first rotation speed detection means) 31 rotation sensor (second rotation speed detection means) 38 controller (deviation calculation means, change amount calculation) means,
(Determination method)

Claims (1)

[Claims] 1. A tractor shift control device including a hydraulically controlled clutch for transmitting rotational power from an engine-side shaft to a transmission-side shaft, the first rotation detecting a rotational speed of the engine-side shaft. Number detecting means, second rotating speed detecting means for detecting the rotating speed of the transmission side shaft, deviation calculating means for calculating a deviation between detection values of the first and second rotating speed detecting means, and the deviation Change amount calculating means for calculating a change amount of the transmission, and a determining means for determining a shift position of the transmission or a hydraulic pressure for operating the clutch by performing fuzzy inference using the deviation and the change amount as a condition part membership function. And a gear change control device for a tractor.