JPS61215839A - Controller for automatic transmission - Google Patents

Abstract

PURPOSE:To reduce the memory capacity necessary for back-up control by inputting the engine load signal and the speed signals in two different power transmission systems into a control means for speed-change-controlling an automatic transmission. CONSTITUTION:A load sensor 2 for detecting the engine load and speed sensors 92 and 93 in two different power transmission systems are provided. An anomaly detecting means 94 for detecting the anomaly of the load sensor 2 or one of the speed sensors 92 and 93 is installed. Further, a control means 98 which receives the output of the load sensor 2 or one of the speed sensors 92 and 93 and speed-change-controls the speed-change gear mechanism of a speed change gear 3 on the basis of the engine load signal and the speed signal of one of the power transmission systems and performs speed-change control by the signal of the other speed sensor when the signal which represents the anomaly is input from the anomaly detecting means 94 is installed. With such constitution, the memory capacity can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control device for controlling an automatic transmission installed in a vehicle, and particularly to a control device for controlling an automatic transmission mounted on a vehicle. This relates to backup control performed when the engine h load signal or the speed signal of the power transmission system is abnormal when changing gears.

(Prior Art) Conventionally, as a method for back-up control of an automatic transmission when a control input signal is abnormal, for example, Japanese Patent Laid-Open No. 57
- As disclosed in Publication No. 65454, the presence or absence of an abnormality in a signal corresponding to the vehicle speed is detected, and if the signal is abnormal, the engine output shaft and the input shaft of the transmission float mechanism are directly connected. Devices in which the operation of the lock-up device is forcibly released are known.

(Problems to be Solved by the Invention) By the way, when the speed change control of an automatic transmission is performed based on both an engine load signal and a speed signal of the power transmission system, as in the above conventional example, an abnormality in the input signal may occur. From the idea of backing up the speed change control at times, two different speed signals in the power transmission system, such as the torque converter's turbine rotational speed and the vehicle speed, are input to the control system, and under normal conditions, the engine load signal and The speed change of the transmission is controlled based on the speed signal of one side of the power transmission system, and when the speed signal of one of the power transmission systems is abnormal, the speed signal of the power transmission system used for speed change control is controlled from the speed signal of the one side. It is conceivable to switch to the other signal and control the speed change of the transmission based on both the speed signal and the engine load signal of the other signal.

However, in that case, when the speed signal of one side of the power transmission system is abnormal, the transmission is backed up based on the speed signal of the other side of the power transmission system and the engine load. However, in addition to the normal shift control map, it is necessary to store a control map regarding the engine load and the speed of the other side of the power transmission system for backup control.
There is a problem that the memory capacity of the control device increases.

Furthermore, since the engine load signal is also required during backup control, there is a problem in that if an abnormality occurs in the engine load signal itself, it becomes impossible to perform backup control.

The present invention has been made in view of the above points, and its purpose is to provide a control system with an engine load signal and two signals in the power transmission system.
In normal conditions, the engine load signal and one speed signal of the power transmission system are used as control signals, while they are used for normal speed change control.
When there is an abnormality in the ill signal, by performing backup control based only on the remaining speed signals of the power transmission system, the memory capacity for backup control can be reduced without significantly sacrificing control functions. The objective is to significantly reduce the load and also to be able to cope with abnormalities in the engine load signal.

(Means for Solving the Problems) In order to achieve the object set forth in L, the solving means of the present invention is as follows:
As shown in the figure, there is a load sensor 91 that detects the load state of the engine 1 based on the throttle opening, etc., and a speed of the power transmission system that transmits the rotation of the engine 1 to the wheels, such as the turbine rotation of the torque converter 7 in an automatic transmission. There are two types of speed at? that detect two different speeds from speed, vehicle speed, engine rotation speed, etc. sensors 92 and 93, and an abnormality detection means 94 for detecting an abnormality in the load sensor 91 or one of the speed sensors 92. Furthermore, upon receiving the output from the load sensor 91 and one speed sensor 92, the speed change gear mechanism 4 of the transmission 3 is changed to a speed v11 based on the engine load signal and one speed signal of the power transmission system.
111, and when a signal indicating an abnormality in the load sensor 91 or one speed sensor 92 is inputted from the abnormality detection means 94, the speed change gear mechanism 4 is shifted based only on the speed signal from the other speed sensor 93. The configuration includes a control means 98 for controlling.

(Function) With the above configuration, in the present invention, signals are inputted to the control means 98 from the load sensor 91 and the two types of speed sensors 92 and 93, respectively.
The gear shift 1l of the transmission 3 is based on the engine load signal from the engine load signal and the speed signal from the speed sensor 92 on one side of the power transmission system.
The Iil vehicle mechanism 4 is controlled.

On the other hand, when the load sensor 91 or one of the speed sensors 92 used for the normal speed change control is in an abnormal state due to a failure or the like, the abnormality detection means 94 detects this and the abnormality detection means 94 sends the control means to the control means. A signal indicating an abnormality is output to the control means 98, and upon receiving this abnormal signal, the control means 98 ignores the engine load signal and operates the speed change gear mechanism based only on the speed signal from the other speed sensor 93 of the power transmission system. 4 is under backup control.

At this time, during the backup control, the shift 113 is controlled by only one speed signal of the power transmission system, so there is no need to store the engine load for the backup control, and the control map is one-dimensional. The memory capacity of the control means 98 is reduced accordingly.

Further, since the normal load signal is ignored during the backup control, even if an abnormality occurs in the engine load signal due to a failure of the load sensor 991, etc., the transmission 3 can be controlled as a backup without being affected by the abnormality.

(Example) Hereinafter, an example of the F1 invention will be described based on the drawings from FIG. 2 onwards.

FIG. 2 shows the overall configuration of an automatic transmission control device according to an embodiment of the present invention, in which 1 is an in-vehicle engine having an output shaft 2;
Reference numeral 3 denotes an electronically controlled automatic transmission that changes the speed of the engine 1 and transmits it to the drive wheels (not shown) of the vehicle. , a speed change gear mechanism 4 as a speed change element, and a lock-up clutch 6 disposed between the input shaft 5 of the speed change gear mechanism 4 and the output shaft 2 of the engine 1 and directly connecting the two wheels 2.5. It consists of a torque converter 7.

The torque converter 7 includes a pump 8 coupled to the output shaft 2 of the engine 1, a turbine 9 disposed opposite the pump 8, and a stator 10 disposed between the pump 8 and the turbine 9. The input shaft 5 of the speed change gear mechanism 4 is coupled to the turbine 9. Further, the lock-up clutch 6 is provided between the input shaft 5 of the speed change gear mechanism 4 and the pump 8, and the lock-up clutch 6 is operated by the pressure of hydraulic oil circulating within the torque converter 7. The output shaft 2 of the engine 1 and the input shaft 5 of the speed change gear mechanism 4 are directly connected to each other. Cancel direct connection.

Further, the speed change gear mechanism 4 is composed of a multi-stage gear mechanism 11 connected to the input shaft 5, and an overdrive planetary gear mechanism 28 installed between the multi-stage gear mechanism 11 and the torque converter 7. There is. The above multi-stage gear mechanism 11
has a front planetary gear mechanism 12 and a rear planetary gear mechanism 13, and the sun gear 14 of the front planet 111m41#112 and the sun gear 15 of the rear planetary gear mechanism 13 are connected by a connecting shaft 16. The input shaft 17 of the multi-stage gear mechanism 11 is connected to the connecting shaft 16 via a front clutch 18, and to the internal gear 2o of the front planetary gear mechanism 12 via a rear clutch 19.

A front brake 21 is provided between the connecting shaft 16, that is, the sun gear 14.15, and the transmission case 3a. The planetary carrier 22 of the front planetary gear mechanism 12 and the internal gear 23 of the rear planetary gear mechanism 13 are connected to an output shaft 24, and there is a space between the planetary carrier 25 of the rear planetary gear mechanism 13 and the transmission case 3a. A brake 26 and a one-way clutch 27 are provided. The multi-stage MS transmission mechanism 11 is of a conventionally known type and has three forward speeds and one reverse speed, and a clutch 1.
8.19 and brakes 21.26 as appropriate to obtain the required gear position.

Roughly speaking, the overdrive planetary gear mechanism 28 is as follows:
A planetary carrier 30 rotatably supporting the planetary gear 29 is connected to the speed change gear mechanism/first input shaft 5, and a sun gear 31 is connected to an internal gear 33 via a direct coupling clutch 32. An overdrive brake 34 is provided between the sun gear 31 and the transmission case 3a, and the internal gear 33 is connected to the input shaft 17 of the multi-stage gear mechanism 11. And the overdrive planetary gear mechanism 2
8 connects the shafts 5 and 17 in a direct connection state when the direct coupling clutch 32 is engaged and the brake 34 is released, and when the brake 34 is engaged and the clutch 32 is released, the shaft 5.
, 17 in overdrive.

Also shown in the lower part of FIG. 3 is a hydraulic control circuit 40 for hydraulically controlling the actuators of various friction elements and the lock-up clutch 6 in the transmission gear mechanism 4 of the transmission 3.

The hydraulic control circuit 40 has an oil pump 41 driven by the engine 1, and the pressure of hydraulic oil discharged from the oil pump 41 into a pressure line 62 is adjusted by a pressure regulating valve 46 and sent to the select valve 42. It is designed to guide you. The select valve 42 includes 1.2. D, N, R,
P shift range positions, and when the shift range positions are at the 1.2 and P positions, the pressure line 62 communicates with the boats 42a-42c of the select valve 42. The boat 42a of the select valve 42 is connected to an actuator 56 for operating the rear clutch 19, and when the select valve 42 is in the above-mentioned position, the rear clutch 19 is maintained in an engaged state. The boat 42a of the select valve 42 is also connected to the 1-2 shift valve 43 near the left end in the figure, and pushes its spool 43a to the right in the figure. Furthermore, the same boat 42a is in the 15th inn 6th
3 to the right end in the drawing of the 1-2 shift valve 43, the 25th inn 64 to the right end in the drawing of the 2-3 shift valve 44, and the 3-4 to the 35th inn 65 to the right end in the drawing. In the diagram, the shift valves 45 are connected to the upper ends thereof, respectively. Above 1st. The second and third lines 63 to 65 each have a first line. Second and third drain lines 67 to 69 are branched and connected, and these drain lines 67 to 69 are connected to first drain lines that open and close the drain lines 67 to 69, respectively. 2nd and 3rd
The solenoid valves 52 to 54 are connected, and when the solenoid valves 52 to 54 are energized and energized, each drain line 67 to 69 is closed while the pressure line 62 and the boat 42a of the select valve 42 are in communication. This increases the pressure within the first to third lines 63 to 65.

Further, the boat 42b of the select valve 42 is connected to the second lock valve 47 via a line 79, and the pressure from this boat 42b is applied to the spool 4 of the second lock valve 47.
It acts to push down 7a in the figure. and,
When the spool 47a of the second lock valve 47 is in the lower position, the line 79 and the line 80 communicate with each other, and hydraulic pressure is introduced into the engagement side pressure chamber 57a of the actuator 57 of the front brake 21 to actuate the front brake 21. The device is configured to be held in the same direction.

Further, the boat 42c of the select valve 42 is connected to the second lock valve 47, and the pressure from the boat 42C acts to push the spool 47a of the second lock valve 47 upward in the figure. Also, the same boat 42C
is connected to the 2-3 shift valve 44 via a pressure line 72.

The pressure line 72 is increased by the energization of the solenoid valve 53 of the second drain line 68.
Spool 448 of 2-3 shift valve 44 due to pressure in 4
When it moves to the left in the figure, it communicates with line 73. The line 73 is connected to the release side pressure chamber 57b of the actuator 57 of the front brake 21, and when hydraulic pressure is introduced into the pressure chamber 57b, the actuator 57
actuates the brake 21 in the release direction against the pressure in the engagement side pressure chamber 57a. In addition, the pressure in the line 73 is
It is also guided to the actuator 58 of the front clutch 18, and engages and operates the clutch 18.

The select valve 42 also has a boat 42d that communicates with the pressure line 62 in its 1st shift range position,
This boat 42d reaches the 1-2 shift valve 43 via a line 74, and is further connected to the actuator 59 of the rear brake 26 via a line 75. Above 1
-2 shift valve 43 and 2-3 shift valve 44 operate when solenoid valves 52 and 53 are excited by a predetermined signal.
The respective spools 43a and 44a are moved to switch lines, whereby a predetermined brake or clutch is actuated to perform a speed change operation between 1st and 2nd speeds and between 2nd and 3rd speeds, respectively.

Further, 48 is a cutback valve that stabilizes the oil pressure from the pressure regulating valve 46, 49 is a vacuum throttle valve that changes the line pressure from the pressure regulating valve 46 according to the magnitude of the intake negative pressure of the engine 1, and 50 is the vacuum valve. This is a throttle backup valve that assists the throttle valve 49.

Further, the hydraulic control circuit 40 is provided with an actuator 60 controlled by the 3-4 shift valve 45 in order to control the operation of the clutch 32 and brake 34 of the overdrive play wm'rn mechanism 28. There is. The engagement side pressure chamber 60a of the actuator 60 is connected to the pressure line 6.
2, and the pressure of the line 62 pushes the brake 34 in the engaging direction. In addition, the 3-4 shift valve 45 is the 1-2 and 2-3 shift valve 43.44.
Similarly, when the solenoid valve 54 is excited, its spool 45a moves downward in the figure. This spool 45
With the movement of a, the communication between the pressure line 62 and the line 76 via the line 71 is cut off, and the line 76 is drained, thereby causing the actuator 6 of the brake 34 to
The hydraulic pressure acting on the release side pressure chamber 60b disappears, and the brake 34 is actuated in the engaging direction, and the 7 actuator 61 of the clutch 32 acts to release the clutch 32.

Generally, the hydraulic control circuit 40 is provided with a lock-up control valve 51. This lock-up control valve 51 is connected to the boat 4 of the select valve 42 via a fourth line 66.
2a. Similarly to the drain lines 67 to 69, a fourth drain line 70 having a fourth solenoid valve 55 as an electromagnetic means is branched and connected to the inlet 66 indicated by L. Then, when the drain line 70 is closed by the power supply excitation of the solenoid valve 55 and the pressure in the line 66 increases, the lock-up control valve 51 causes the spool 51a to cut off communication between the lines 77 and 78, 78 is drained, the above O
The pull-up clutch 6 is moved in the connecting direction.

In the above configuration, the operational relationship between each gear stage, lockup, and each solenoid valve, and the operational vJ relationship between each gear stage, clutch, and brake are shown in Tables 1 to 3 below.

In Table 1 and FIG. A throttle opening sensor 91 detects the load of the engine 1 based on the opening degree (throttle opening/closing) of the throttle valve 1b that opens and closes the intake passage 1a of the engine 1, and a turbine in the torque converter 7 that constitutes the power transmission system. A turbine rotation speed sensor 92 as a speed sensor that detects the rotation speed T of 9 by 1 degree, and an output shaft rotation speed V (
In other words, each output of the transmission output shaft rotation speed sensor 93 as a speed sensor that detects the vehicle speed) and the abnormality detection means 94 that detects an abnormality due to a failure of the turbine rotation speed sensor 92 (one speed sensor), etc. A signal is being input.

The abnormality detection means 94 includes, for example, as shown in FIG. When V is larger than a predetermined value Vo, outputting a Hi-multiple signal causes a second comparator 94b, an inverter 94c that inverts the output signal of the first comparator 94a, and an inverter 94c and the second When each output signal of the comparator 94b is both at the 1-1i level, an H signal is detected as an abnormality detection signal.
It consists of an AND gate circuit 94d that outputs one signal,
When the transmission output shaft rotation speed V is higher than the predetermined value Vo, that is, the vehicle is running at a certain abnormal speed, and the turbine rotation speed T is lower than the predetermined value φrpm, an abnormality is detected in the turbine rotation speed sensor 92. It determines that an abnormality has occurred and outputs an abnormality detection signal.

As shown in FIG. 4, the electronic control circuit 90 has a shift-up shift line LLI and a shift-down shift line ld, which are set in advance based on the characteristics of the throttle opening (engine load) with respect to the turbine rotation speed. Two-dimensional map of shifting characteristics, lock-up operation control line LfIN and lock-up release control line LρF set in the same way
A two-dimensional map of lock-up characteristics having
and a one-dimensional map of backup characteristics having a downshift line Vd, and throttle opening r!
The actual throttle opening (engine load) and turbine rotation speed T detected by the I sensor 91 and the turbine rotation speed sensor 92 are stored in the electronic control circuit 90. Each shift #Lu, Ld and lock-up control of the characteristic map are stored. A comparison is made with the line LIN1LJF to calculate whether or not to shift or not and to determine whether or not to lock up. ~ Output to 55. Further, when an abnormality detection signal indicating an abnormality in the turbine rotation speed signal is input from the abnormality detection means 94 to the electronic control circuit 90, a lock-up OFF signal is sent to the solenoid valve 55 of the hydraulic control circuit 40.
to release the lock-up of the transmission 3, and based only on the rotational speed signal from the transmission output shaft rotational speed sensor 93, the signal is output to the shift-up shift line VU and shift-down shift line VU in the one-dimensional map of backup characteristics. It is configured to compare with the shift line Vd to calculate whether or not to shift, and output an ON-OFF signal for shifting to the solenoid valves 52 to 54 of the hydraulic control circuit 4o.

Here, the control procedure for the automatic transmission 3 by the electronic control circuit 90 will be further explained in detail.

The main routine of the program installed in the computer of this electronic control circuit 90 is executed according to the flowchart shown in FIG. That is, in this speed change control, initialization setting is performed in step S1 after the start.

This initialization setting starts with automatic gear shifting! The ports of various control valves and necessary counters in the oil pressure t11 control circuit 40 of the IA3 are initialized, and the speed change gear mechanism 4 is set to the first
The lock-up clutch 6 is set to a released state and the lock-up clutch 6 is set to a released state. After that, in step S2, based on the output signal of the abnormality detection means 94, the presence or absence of a failure or abnormality in the control sensor for controlling the speed change gear mechanism 4 of the transmission 3, that is, the turbine rotation speed sensor 92, is detected. Proceeding to step S3, it is determined whether or not the turbine rotational speed sensor 92 has failed. If the determination is No, indicating that there is no failure, normal speed change control and lock-up control are performed. In this normal control, in the first step S4, it is determined whether the position of the select valve 42, that is, the shift range is lunge, and if this determination is YES, the process moves to step S5, and the hydraulic control circuit 4o
The lock-up is released by outputting an ON signal to the fourth solenoid valve 55, and then, in step S6, it is calculated whether or not the engine 1 will overrun when the gear position of the transmission gear mechanism 4 is downshifted to the first speed. do. After that, in step S7, it is determined whether or not there will be an overrun based on the above calculation, and if this determination is YES, in step S8, the gear tooth win mechanism 4 is set to 2nd speed.
If NO, a signal is issued to the solenoid valves 52 to 54 of the hydraulic control circuit 40 to control the shift valves so as to shift to the first speed, respectively, in step S9. After that, the process returns to the initial step S2.

On the other hand, when the determination in step S4 is No, it is determined in step S10 whether or not the shift range is 2 range, and this determination is YES.
If so, the process moves to step So to release the lock-up, and after changing the speed change gear mechanism 4 to the second speed in step S12, the process returns to step S2. Further, when the determination in step S+o is No, that is, when the shift range is the D range, step 813
-S+s, shift-up control including shift-up determination, shift-down control including shift-down determination, and lock-up control including lock-up determination are performed in order.

The above shift-up control is performed based on the shift-up control subroutine shown in FIG. That is, first, in step 3u1, the gear change gear! 11 Read the gear position of mechanism 4, and determine whether the read gear position is 4th gear or not. If this determination is YES, no further upshifts can be performed, so the gear position remains unchanged. End control. On the other hand, if the determination in step Su+ is No, the throttle opening is read in step Suz, and in the next step 5t13, the read throttle opening is compared with the shift-up shift line LLI in the shift-up map shown in FIG. Then, the set turbine rotation speed Tl1lap on the map corresponding to the throttle opening is read. Next, in step 814, the actual turbine rotation speed T is read, and then in step 3u5, it is determined whether or not the rotation speed T is larger than the set turbine rotation speed Tmap, and this determination is YES for T>Tl1lap. In some cases, the shift up flag F1 is set to Fl in step 3u6.
-0 or not. This flag F+ is set to Fl-1 when an upshift is executed, and stores the history of the upshift state.

If the determination in step Sue is NO, an upshift is being performed, so the control is immediately terminated. If the determination is YES, the flag F1 is set to Fl-1 in step Su7, and then the gear position of the transmission gear mechanism 40 is shifted up by one step in step 5LIs, and υ1111 is ended.

On the other hand, the determination in step Su5 is N of Tl1lap.
o, in step Sus, the set turbine speed T map is corrected by multiplying the set turbine speed T map by a coefficient of 0.8, and a new shift with hysteresis as shown by the broken line in FIG. 8 is performed. An up-shift line L Ll is formed. Next, step SIJ+
In e, similarly to step 3u5 above, it is determined whether the actual turbine rotation speed T is larger than the corrected set turbine rotation speed 1'-map, and this determination is determined as Y.
If the answer is ES, the control is left as is, and if the answer is No, the upshift flag F+ is reset to F+=O in step Sn, and then the control is ended. With the above steps, the subroutine for shift-up control is completed.

Shift down control including a downshift determination performed after execution of such upshift control is performed based on the downshift control subroutine shown in FIG. In this downshift control, as in the case of the upshift control, first, in step Sd1, the gear position of the transmission gear mechanism 4 is read out, and it is determined whether the gear position is the first speed.

If this determination is YES, it is not possible to downshift any further, so the control is immediately terminated. on the other hand,
The determination in step Sd+ above is N.

Then, in step Sd2, the throttle opening is read, and in the next step Sd3, the read throttle opening is compared with the downshift shift line Ld of the downshift map shown in FIG. Read the set turbine rotation speed Tmap on the map. Next, in step Sd4, the actual turbine rotation speed T is read out, and in the subsequent step Sds, it is determined whether the actual turbine rotation speed T is smaller than the set turbine rotation speed Tmap. This judgment is Y of T < T map
When it is ES, in step Sds, it is determined whether the shift down flag F2, which is set to "1°" when downshifting is executed, is F2-0,
If this determination is NO, a downshift is being performed, and the control is then terminated. On the other hand, if the determination in step Sd6 is YES, step Sd
After setting the downshift flag F2 to F2-1 in Step A, the gear shift tooth '$1114111 is set in Step Sda.
The gear position of No. 4 is shifted down by one step, and then the control is terminated.

On the other hand, the determination in step Sds above is N of T≧Teap.
0, in step Sdq, the set turbine rotation speed T map is divided by a coefficient of 0.8 to correct it, and a new downshift shift line 1- with hysteresis as shown by the broken line in FIG. 10 is created. form d'. Next, in step 5dII+, it is determined whether the actual turbine rotation speed T is smaller than the corrected set turbine rotation speed Tmap.
Then, the downshift flag F2 is reset to F2-0, and each control ends. The above completes the subroutine for downshift control.

Roughly speaking, after executing such downshift control, the first lock-up control including lock-up determination is performed as described above.
This is performed based on the lockup υ control subroutine shown in FIG. In the lock-up control, first, the throttle opening is read in the first step SIl+, and the read throttle opening is changed to the twelfth throttle opening in the next step 5fIz.
The set turbine rotation speed Tmap @ on the map corresponding to the throttle opening is read by comparing it with the lock-up release control line LIIF of the lock-up release map shown by the broken line in the figure. Thereafter, in step S93, the actual turbine rotation speed is read, and in the next step 814, it is determined whether or not the turbine rotation speed is smaller than the set turbine rotation fl(Tmap). If this determination is YES, The process moves to step 5its, where the lock-up clutch 6 is put into a non-operating state to release the lock-up, and then the control ends.On the other hand, when the determination in step 8114 is NO, the process moves to step 5lle, where the lock-up clutch 6 is deactivated and the lock-up is released.
3) Compare the throttle 141 read in + with the lock-up operation control line LRN of the O-lock-up operation map shown by the solid line in FIG. 5lly, the actual turbine rotation speed Tm is the set turbine rotation speed Tm read out in step 5116.
ap is determined, and if this determination is YES, the lock-up clutch 6 is activated in step S's.
After turning on and locking up the transmission 3,
Again, the verdict is N.

If , respectively, 1II (control ends).

With the above steps, lockup control is completed.

Regarding the above control, the determination in step S3 is ゛°
If there is a dead camp “°” is YES, step S +
In addition to performing backup control in s, step S1
At step 7, the process of displaying an alarm on the warning device to indicate the execution of the backup control is repeated. The backup control described above is performed based on the backup control subroutine shown in FIG. That is, in the first step Sb1, the lock-up clutch 6 is turned OFF to release the lock-up of the shift vs3, and then in step Sb2, the shift □output shaft rotation speed V is changed based on the output signal of the transmission output shaft rotation speed sensor 93. Then, in step Sb3, the transmission output shaft rotation speed Vu on the upshift line VIJ is read from the backup map shown in FIG. It is determined whether the rotational speed V is larger than the same rotational speed VLI on the map. When this determination is YES for V>VLI, the process moves to step Sbs and it is determined whether or not the shift up flag F1 is F+-0, and when this determination is No, the control is directly terminated, while YES. In some cases, the upshift flag F+ is set to F+=1 in step Sbs, and the gear position of the transmission gear mechanism 4 is shifted up by one gear in step Sb7, and then the control is ended.

On the other hand, when the determination in step Sb< is NO that V≦Vu, the process moves to step Sbs, reads the transmission output shaft rotation speed Vd on the downshift shift line Vd from the backup map, and then proceeds to step Sbs. The actual transmission data read in step Sb2 above.
It is determined whether the shaft rotational speed V is smaller than the same rotational speed Vd on the map, and when this determination is No (V≧Vd), the control is terminated. Further, when the determination in step Sbs is YES of v<Vd, step Sb+ is performed.

It is determined whether the shift down flag F2 is F2-0 or not, and if the determination is NO, the control is immediately terminated, while if the determination is YES, the control is terminated at step 3.
The shift down flag F2 is set to F2-1 at step bu, and the gear position of the transmission gear mechanism 4 is downshifted by one gear at step Sb12, and then the control is ended.

Therefore, in this embodiment, each output signal of the throttle opening sensor 91 and the turbine rotation speed sensor 92 is input in step S+s, that is, the lock-up control subroutine, and the predetermined throttle opening (engine load) and turbine rotation are input. A lock-up control means 95 is configured to control activation/deactivation of the lock-up clutch 6 based on lock-up characteristics related to the number of lock-ups.

Further, in steps 813 and 814, that is, the shift up control routine and the shift down control routine, the throttle opening sensor 91 and the turbine rotation speed sensor 9
2, and controls the activation/deactivation of each actuator of the transmission gear mechanism 4 based on preset upshift and downshift characteristics regarding throttle opening and turbine rotation speed. Means 96 are configured.

Roughly speaking, when a signal indicating an abnormality in the turbine rotation speed sensor 92 is input from the abnormality detection means 94 in step 816, that is, in the backup control routine,
In place of the speed change control by the speed change control means 96, a backup control means 97 is configured to back up control the transmission gear mechanism 4 based only on the transmission output shaft rotation speed signal from the transmission output shaft rotation speed sensor 93. has been done.

The speed change control means 96 and the backup control means 97 constitute a control means 98 in the present invention.

Therefore, in the above embodiment, under normal conditions, the throttle opening signal output from the throttle opening sensor 91 and the turbine rotation speed signal output from the turbine rotation speed sensor 92 are transmitted to the speed change control means 96 and the lockup control means 95. It is inputted into the control means 95 and 96 and compared with the characteristic maps stored in the control means 95 and 96, and based on this comparison, the speed change control and lock-up control of the speed change gear mechanism 4 are performed.

On the other hand, when an abnormality occurs in the output signal of the turbine rotation speed sensor 92 due to a failure or the like, the abnormality detection means 94 detects this and outputs an abnormality detection signal. The abnormality detection signal from the detection means 94 inhibits both the shift control by the shift control means 96 and the lockup control by the lockup control means 95, and allows the backup control means 97 to perform shift control and lockup control. Through this backup control, the lock-up operation of the shift vs3 is forcibly released, and the rotation speed signal from the transmission output shaft rotation speed sensor 93 is compared against a preset one-dimensional backup characteristic map. Based on the comparison, the speed change mrJi mechanism 4 of the speed change IR3 is controlled.

In that case, when the turbine rotation speed sensor 92 is abnormal, the speed change gear mechanism 4 is subjected to backup control based only on the rotation speed signal from the transmission output shaft rotation speed sensor 93, so the map of backup characteristics used for backup control is Since the map is one-dimensional, the memory capacity required to form the map is small, and the memory capacity for backup control can be significantly reduced.

In addition, in the backup control described above, since the speed change gear mechanism 4 is controlled to change speed based only on the rotation speed signal detected by the transmission output shaft rotation speed sensor 93, an abnormality detection means for detecting an abnormality in the 1-throttle opening sensor 91 If the backup control means 97 is activated when an abnormality signal is output from the abnormality detection means, the speed change gear mechanism 4 can be controlled as a backup even when the throttle opening sensor 91 is abnormal.

In the above embodiment, the characteristic map for backup control is a one-dimensional map related only to the transmission output shaft rotation speed, but it is also possible to utilize the output signal from the kickdown switch, which is turned ON when the accelerator pedal is fully depressed. Then, the kickdown switch was turned on. In other words, when the throttle opening is fully opened by fully depressing the accelerator pedal, as shown in FIG. It may be shifted to the high speed side, and in addition to achieving the same effect as the above embodiment, the control characteristics in the backup control can be switched depending on whether or not the throttle opening is fully opened.
This has the advantage of improving vehicle running performance, driving feeling, etc.

Further, in the above embodiment, in normal times, normal gear change control is performed based on the throttle l1l (engine load) of the engine 1 and the turbine rotation speed of the torque converter 7, and when the turbine rotation speed signal is abnormal, the transmission output shaft The gear change was controlled based only on the rotational speed signal, but on the other hand, the throttle opening signal and the transmission output shaft rotational speed signal were used during normal times, but the change was made so that only the turbine rotational speed signal was used during abnormal conditions. Furthermore, the engine rotation speed signal may be used as the speed signal of the power transmission system used for normal speed change control or backup control in case of an abnormality.

(Effects of the Invention) As described above, according to the present invention, the engine load signal and the speed signals of two different systems of the power transmission system are input to the control means for controlling the speed change of the automatic transmission, During normal times, the transmission is controlled based on the engine load signal and one speed signal of the power transmission system, but when the two control signals used during normal times become abnormal,
By performing backup control of the transmission based only on the speed signal of the other side of the power transmission system, the memory capacity required for backup control can be reduced and the memory capacity of the entire control system can be significantly reduced. In addition, it is possible to achieve a practical effect of being able to reliably carry out backup control even when the engine load signal is abnormal.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of the present invention. Figures 2 to 15 show embodiments of the present invention, with Figure 2 showing the overall schematic configuration of the control device for an automatic transmission, and Figure 3 showing the structure and hydraulic control circuit of the mechanical part of the automatic transmission. FIG. 4 is an explanatory diagram showing characteristic maps for shift control and lock-up control used in normal times; FIG. 5 is a block diagram illustrating abnormality detection means for detecting abnormality in the turbine rotation speed sensor; FIG. 6 is a flowchart showing the main routine of the shift control, FIG. 7 is a flowchart showing the shift-up control subroutine of the shift control, FIG. 8 is an explanatory diagram of the shift-up map, and FIG. 9 is the shift-down control subroutine. 10 is an explanatory diagram of the shift-down map, FIG. 11 is a flowchart diagram showing the lock-up control subroutine, FIG. 12 is an explanatory diagram of the lock-up map, and FIG. 13 is a flowchart diagram showing the backup control subroutine. 14 is an explanatory diagram of the backup map, and FIG. 15 is a diagram corresponding to FIG. 14 showing a modified example. DESCRIPTION OF SYMBOLS 1... Engine, 3... Automatic transmission, 4... Speed change gear mechanism, 6... Lock-up clutch, 7... Torque converter, 40... Hydraulic control circuit, 90...
Electronic control circuit, 91... Throttle opening sensor, 92
...Turbine rotation speed sensor, 93...Transmission output shaft rotation speed sensor, 94...Abnormality detection means, 95...
Lock-up control means, 96... Speed change control means, 97
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Claims (1)

[Claims] (1) A load sensor that detects the engine load, and 2 that detects the speed of two different systems in the power transmission system.
an abnormality detection means for detecting an abnormality in the load sensor or one of the speed sensors; and an engine load signal and one speed signal of the power transmission system that receives outputs from the load sensor and one of the speed sensors; When a signal indicating an abnormality in the load sensor or one speed sensor is inputted from the abnormality detection means, the speed change gear mechanism of the transmission is controlled based on the speed signal from the other speed sensor. 1. A control device for an automatic transmission, comprising: control means for controlling the speed change of a speed change gear mechanism.