JP2699193B2 - Transmission control device for automatic transmission - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for an automatic transmission in which a shift end determination is accurately performed.

(Prior Art) Conventionally, there have been proposed various shift control technologies in which a shift operation of an automatic transmission is electronically controlled using a microcomputer, and in this case, power in the automatic transmission is changed according to a shift command. A method of detecting when the transmission path has been switched and the shift has actually been completed is known, for example, as disclosed in JP-A-61-144465.

The determination of the end of the shift in the preceding example is made by comparing the turbine speed before and after the shift according to the shift gear ratio, and the change becomes a predetermined state, or the shift corresponding to the shift time normally required from the start of the shift. The set time is set as long as possible, and if the elapsed time from the start of the shift exceeds this set value, the end of the shift is determined.

(Problems to be Solved by the Invention) However, in the shift end determination as described above, it is not possible to set a determination reference value corresponding to a change in shift time based on a change in viscosity with respect to a change in oil temperature, and to set an elapsed time. If the value is large, the transition to the next control is delayed, and if the value is short, the end determination is made before the end of the shift when the shift time is long in the cold state, and based on the shift determination at the shift speed after the shift. An erroneous speed change operation may occur, causing a hunting phenomenon in the control, leading to unstable control.

In view of the above, for example, it is conceivable that the set value of the elapsed time is set to be long in a cold state for a predetermined time after the start, but the setting has the same problem as described above.

Accordingly, the present invention has been made in view of the above circumstances, and determines the end of a shift based on a change in turbine speed and elapsed time.
It is an object of the present invention to provide a shift control device for an automatic transmission in which the setting of the elapsed time is accurately performed in accordance with the state at that time.

(Means for Solving the Problems) To achieve the above object, a shift control device for an automatic transmission according to the present invention, as shown in the basic configuration diagram of FIG. Gear shift control means B for shifting gears by the switching operation of the solenoid valve. The shift control means B outputs a shift signal to the automatic transmission A so as to achieve a shift speed determined according to a shift map or the like.

Further, a shift end determining means C for determining the end time of the shift of the automatic transmission A by the shift control means B is provided. The shift end determining means C makes a shift end determination when a change in the drive shaft rotation speed on the input side of the automatic transmission, such as the turbine rotation speed or the engine rotation speed, is brought into a predetermined state. The shift end determination is also performed when the shift elapsed time from the time exceeds the set value, and the shift end timing is determined by at least one of the determinations. Further, an elapsed time setting means D for setting the set value of the shift elapsed time is provided.

On the other hand, there is provided a shift time detecting means E for detecting a shift time from the shift command to the end of the shift, and based on the shift time detected by the shift time detecting means E, the shift elapsed time by the elapsed time setting means D is determined. A correction means F for changing a set value is provided.

Further, as another invention, the elapsed time setting means D includes:
In the predetermined post-start period, the set value of the shift elapsed time used for the shift end determination is set to be long, and the correction means F determines the elapsed time based on the shift time detected by the shift time detecting means E. Control is performed to change the post-start period in which the setting value of the shift elapsed time is increased by the setting means D.

(Operation) In the shift control device as described above, the end of the shift is determined by:
The shift end determination is also performed when the change in the drive shaft rotation speed due to the shift is in a predetermined state, or when the shift elapsed time from the start of the shift exceeds a set value. The shift time is detected, the set value of the shift elapsed time in the shift end determination is corrected based on the shift time, and the shift end determination is set so as to approach the actual shift end timing. Control of various controls based on the shift end determination I try to improve the accuracy.

In the case where the set value of the shift elapsed time used for the shift end determination is set long so as to correspond to the viscosity change at low temperature of the oil during the predetermined period after the start, the shift time similarly detected , The setting of the post-start period in which the set value of the shift elapsed time is lengthened is changed, and the accuracy of the shift end determination is improved in accordance with an environmental change or the like.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. Second
The figure shows a schematic configuration of a shift control device for an automatic transmission.

The output of the engine 1 is input to the automatic transmission 3 via the torque converter 2 and the solenoid valve of the automatic transmission 3
The speed is changed by the drive controls 4 and 5, and the speed is output to the propeller shaft 6. The solenoid valves 4 and 5 of the automatic transmission 3 are provided, for example, three for shifting and one for lock-up, and a friction element by a clutch or a brake inside the transmission is operated by a combination of the respective operations, and gear shifting is performed. Switching the power transmission path of the mechanism,
The gear is operated to shift to a gear speed such as a speed, and the engagement / release of the lock-up clutch is operated. Note that details of the internal structure of the automatic transmission 3 are known matters, and a description thereof will be omitted.

The control unit 7 is connected to the solenoid valve 4.
A control signal is output from the CPU and a shift operation is performed based on predetermined shift characteristics in accordance with an operating state such as a turbine speed and a throttle opening (or a vehicle speed and a throttle opening). The control unit 7 is composed of, for example, a microcomputer, and various signals indicating an operation state from sensors installed in each section, for example, a turbine rotation signal from a turbine speed sensor 8 for detecting a turbine speed, a throttle opening of the engine 1. A throttle opening signal from the throttle sensor 9 for detecting the temperature, a temperature signal from the temperature sensor 10 for detecting the oil temperature or the cooling water temperature, and other various signals necessary for the shift control are input.

Then, the control unit 7 performs shift control including normal lock-up based on these detection signals,
The shift end in the shift control is determined by determining the change in turbine speed and the shift elapsed time, and the actual shift time is detected, and the set value in the shift determination is changed based on the shift duration. Thus, control is performed to improve the shift determination system.

The basic process of the change of the turbine speed at the time of the shift and the determination of the end of the shift accompanying the process of the control unit 7 will be described with reference to FIG. As the turbine speed Tsp rises and the shift speed determined from the map set in relation to the throttle opening changes to a higher speed side beyond the shift line, a shift signal is sent to the solenoid valve 4 of the automatic transmission 1 at time t1. Is output. At this time, in response to the power transmission path being switched by the operation of the various friction engagement elements accompanying the operation of the solenoid valve 4, the turbine speed decreases from Tsp1 and the speed Ts corresponding to the transmission gear ratio.
The shift ends at time t2 when the speed has decreased to p2, and then the rotation speed increases. The shift end determination based on the change in the turbine speed Tsp during such shifting is performed by obtaining the turbine speed Tsp2 after shifting from the turbine speed Tsp1 at the time of output of the shift signal, and setting a predetermined range ± α to this speed, When the change rate dTsp / dt of the turbine speed is equal to or less than a predetermined value and the speed itself falls within the predetermined range, it is determined that the speed change is completed.
Further, when the determination based on the turbine speed Tsp cannot be performed, the shift end determination is performed at t3 when the shift elapsed time from the shift signal output time t1 reaches the predetermined value TBU. On the other hand, when the predetermined time Ts has elapsed after the start of the engine, the set value TBU of the shift elapsed time is set longer.

Then, in the shift end determination as described above, the actual shift time t1 to t2 is detected, and the shift time is used to correct the set value TBU of the shift elapsed time and the setting of the predetermined time Ts from the engine start to. Is controlled.

The processing of the control unit 6 will be described with reference to the flowcharts of FIGS. FIG. 3 is a set value correction routine corresponding to the shift end determination. After the control is started, it is determined in step S1 whether a shift command has been output. If the determination is YES and the shift command is output, step S2 is executed.
In the subroutine (FIG. 4), a post-start flag Ax (after the lapse of Ax = 1) is set in accordance with the determination as to whether or not the predetermined period Tsx has elapsed after the start.

In the subroutine of FIG.
Is read, and it is determined whether or not the elapsed time Ts has exceeded the set time Tsx (S22). This judgment is NO
Before the set time Tsx has elapsed, the post-start flag is set in step S23.
Ax is set to 0, and the set value TBU of the shift elapsed time T used in the determination in step S15 described later is set longer by a predetermined value B. On the other hand, the set time Ts
After the lapse of x, the post-start flag Ax is set to 1 in step S24.

Next, in step S3, the temperature TMP (oil temperature or cooling water temperature) is read, and it is determined whether or not this temperature is in an extremely low temperature range higher than the set value TMPx.
Proceeding to step S5, it is determined whether or not the shift has been completed based on a change in the turbine speed, based on whether or not the engagement flag TEG is set to 1. The setting of the engagement flag TEG is performed by a subroutine of FIG. 5, and details thereof will be described later.

If the determination in step S5 is NO and the engagement by the turbine speed is not completed (shift not completed), it is determined in step S15 whether the shift elapsed time T has exceeded the set value TBU, and if one of the determinations is YES If it does, step S10 or
In S16, the shift end flag FIN is set to 1.

First, the determination in step S5 is YES, and the shift is terminated by the determination of the turbine speed. If the shift elapsed time T has not reached the set value TBU, the post-start flag Ax is set to 1 in step S6. It is determined whether or not the post-start period Ts has elapsed.

If the determination in step S6 is YES and the post-start period Ts has elapsed, the set value TBU of the shift elapsed time up to that time is long, so the set value TBU is used as a margin for the shift elapsed time T at that time. A setting is made so that the value is corrected to a value obtained by adding the predetermined value ΔT1. In addition, the correction of the set value TBU includes, in addition, one step time T2 from the set value TBU so far.
(For example, 25 ms).

On the other hand, if the determination in step S6 is NO and before the post-start period Ts has elapsed, in step S7, the correction value ΔT2 of the set value Tsx of the post-start period Ts is set to the set value TBU of the shift elapsed time and the actual shift elapsed time. Calculated based on the difference TBU-T from T, step S8
Then, the correction value ΔT2 is corrected by adding the correction value ΔT2 to the set value Tsx. The setting characteristic of the correction value ΔT2 is such that when the time difference TBU-T is small, the correction value ΔT2 is set to be large in the positive direction, and decreases as the time difference TBU-T increases, and the correction value ΔT2 becomes a large value in the negative direction. Is what you want. Since the actual shift time T is shorter than the set value TBU set to a large value in the predetermined period Ts after the start by this correction, the set value is set so as to narrow an area where the increase of the set value TBU after the start does not need to be corrected. This is for correcting Tsx to be short.

When the determination in step S15 is YES and the post-start elapsed time T exceeds the set value TBU and the shift is ended, after setting the shift end flag FIN in step S16,
In step S17, it is determined whether or not the shift time T exceeds a preset shift upper limit time T1. Shift upper limit time
If T1 has not been exceeded, it is waited in step S18 that the engagement completion flag TEG = 1 based on the determination of the turbine speed is set, and when the engagement is completed within the shift upper limit time T1, the setting value TBU is actually set. Is shorter than the shift time T of
In step S19, a correction is made by adding one step time T2 (for example, 25 ms) to the set value TBU.

On the other hand, if the determination in step S4 is NO and the temperature is extremely low, the shift time becomes extremely long due to the high viscosity.
Proceeding to the speed change step S11, the set value TBU is set to the maximum value A, and the correction is not performed. Then, in step S12, it is determined whether or not the shift is completed by determining that the engagement completion flag is TEG, and in step S13, it is determined whether or not the shift is completed by comparing the shift elapsed time T with the set value TBU.

The setting of the engagement flag TEG will be described with reference to a subroutine of FIG. 5 for an upshift. In step S31, it is determined whether or not the current shift speed is the 4th speed at which no upshift occurs. In step S32, the throttle opening is read. Then, in step S33, the shift turbine speed Tspo corresponding to the shift line of the shift map corresponding to the throttle opening is read, and the current turbine speed is read.
Tsp is detected (S34), and it is determined whether or not an upshift is performed based on whether or not the actual turbine speed Tsp is greater than the speed-changed turbine speed Tspo (S35). If this determination is YES, a determination is made in step S36 as to whether the shift-up flag SUF is being set or not during a shout-up.

If the determination in step S36 is NO and the shift to the current upshift is performed, the upshift flag S is set in step S37.
After setting UF to 1 and resetting the engagement end flag TEG to 0 (engagement not completed), a process for determining a shift end is performed in steps S38 and S39, and step S38 is performed.
At step 40, an upshift command is output.

The shift end (engagement end) determination is made in step S38 by calculating the turbine speed Tsp2 after shifting based on the transmission gear ratio from the turbine speed Tsp1 at the time of the shift command, and step S39.
Then, a set width is set by adding / subtracting a predetermined deviation rotational speed α to / from the turbine rotational speed Tsp2 after gear shifting. The deviation rotational speed α is for compensating that the turbine rotational speed after the upshift does not always become the calculated value in consideration of the gear ratio depending on the operation mode (particularly how the accelerator pedal is depressed).

In step S35, the current turbine speed Tsp
Is not greater than the variable speed turbine speed Tspo, the change rate d of the turbine speed is determined in step S41.
Calculate Tsp / dt. Then, in a step S42, it is determined whether or not the absolute value of the rate of change dTsp / dt of the turbine speed is smaller than a predetermined set value. If this determination is YES, the upshift is in progress, and it is determined in step S43 whether or not the current turbine speed Tsp is within the range of the set width set in step S39. When it is entered, it is determined that the shift is completed in step S44, the upshift flag SUF is reset to 0, and the engagement end flag TEG is set to 1 (engagement end). Accordingly, the shift end determination and the correction process of FIG. 3 are performed.

In the above embodiment, the determination of the post-start period is made based on the time as in the subroutine of FIG. 4. However, the determination may be made based on the number of shifts after the start. after Accumulates number CG that shift command has been output may be set to 1 after starting flag Ax when its value exceeds the set value CG _X. Also in this case, in steps S7 and S8, a correction value is calculated based on the time difference TBU-T as in the previous example, and the set value C
G _X can be corrected.

(Effects of the Invention) According to the present invention as described above, when the end of the shift is determined based on the change in the drive shaft rotation speed or the shift elapsed time accompanying the shift, the actual shift time is detected. By correcting the shift elapsed time set value or the shift elapsed time set value in the shift end determination by the predetermined period after the start, the shift end determination can be performed in accordance with the actual shift end timing. Therefore, it is possible to improve the control accuracy of various controls based on accurate shift end determination.

[Brief description of the drawings]

FIG. 1 is a functional block diagram for clearly showing the configuration of the present invention, FIG. 2 is a schematic configuration diagram of a control device for an automatic transmission in one embodiment, and FIGS. FIG. 6 is an explanatory diagram showing a change in turbine speed during a shift-up shift and a shift end determination. A, 3 ... automatic transmission, B ... shift control means, C ... shift end determination means, D ... elapsed time setting means, shift restriction means, E ... shift time detection means, F ... correction means, 1 ...
Engine 2, Torque converter 4, Solenoid valve 7, Control unit 8, Turbine speed sensor 9, Throttle sensor

Claims (2)

(57) [Claims] When a change in the rotation speed of the drive shaft on the input side of the automatic transmission accompanying a shift is in a predetermined state, a shift end determination is made, and when a shift elapsed time from the start of the shift exceeds a set value. A shift control device for an automatic transmission, comprising: a shift end determining unit for determining a shift end; and an elapsed time setting unit for setting a set value of the shift elapsed time. A shift time detecting means for detecting the shift time, and a correcting means for changing a set value of the shift elapsed time by the elapsed time setting means based on the shift time detected by the shift time detecting means. Transmission control device for transmission. 2. A shift end determination is performed when a change in the drive shaft rotation speed on the input side of the automatic transmission accompanying a shift is in a predetermined state, and when a shift elapsed time from the start of the shift exceeds a set value. A shift control device for an automatic transmission, comprising: a shift end determining unit that also performs a shift end determination; and an elapsed time setting unit configured to set a longer set value of the shift elapsed time during a predetermined post-start period. A shift time detecting means for detecting a shift time from a shift command to the shift end determination; and starting the shift time setting means to increase a set value of the shift elapsed time based on the shift time detected by the shift time detecting means. A shift control device for an automatic transmission, comprising: a correction unit that changes a later period.