JP2698975B2 - Select control device for electronically controlled automatic transmission - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a select control device for an electronically controlled automatic transmission that detects a failure and backs up a hydraulic gear select actuator of the electronically controlled automatic transmission. 2. Description of the Related Art Conventionally, there has been known an electronically controlled automatic transmission in which a drive transistor is operated by electronic control to drive an electromagnetic valve and thereby drive and control a hydraulic gear select actuator. FIG. 3 is a block diagram of a control system of a conventional electronically controlled automatic transmission of this kind, for example, a control system of a 4-position gear select actuator. FIG. 4 (a) shows select switches SW1 to SW4 used in FIG. FIG. 4B is a schematic diagram of a stroke sensor that detects a shift position. In Figure 3, a gear select actuator 10 is controlled by a drive of the electromagnetic valves V _10, V _11, V _12, configured as an electromagnetic valve V _10, V _11, V ₁₂ is actuated by the transistors TR1, TR2, TR3 Have been. As shown in FIG. 4 (a), the electromagnetically controlled automatic transmission includes six forward gears G1 to G6 and one reverse gear GR. The select switches SW1 to SW4 are used to detect when the gear select actuator is operated to the predetermined select position and stop the gear select actuator to set the gear to the predetermined select position. is there. Select switches SW1, SW2, SW3, SW4 are gear GR or G1, gear G2 or G3, gear G4 or G, respectively.
5. It is configured to detect that the gear select actuator is operated at the selected position of the gear G6. The shift position is detected by a gear shift stroke sensor 11 shown in FIG. 4 (b). That is, when the shift position changes, the terminal of the gear shift stroke sensor 11 slides on the resistor 12 having the resistance value R in accordance with the change of the shift position, and accordingly, the voltage V of the terminal of the gear shift stroke sensor 11 changes. The shift position is detected by the minute. (Problems to be Solved by the Invention) However, in the conventional electronically controlled automatic transmission as described above, the select switch SW for detecting the select position is used.
1 to SW4 are electrically or mechanically short-circuited,
When the gear is opened, the gear selection position cannot be detected, so that the gear cannot be selected, and the gear cannot be selected again. The present invention solves the above-mentioned problems, diagnoses a select switch, and when a select switch is abnormal, a select control device for an electronically controlled automatic transmission that does not become uncontrollable to secure vehicle safety by appropriate backup processing. It is intended to provide. (Means for Solving the Problems) An electronically controlled automatic transmission comprising: a plurality of select switches corresponding to each gear position for detecting a gear select position; and diagnostic means for diagnosing a state of each of the select switches. Detecting the state of each of the select switches,
Failure diagnosis means for diagnosing a failure when none of the select switches are turned on, and a plurality of times of a select operation process and a diagnosis of the state of the select switch are performed when the select switch is failed as a result of the diagnosis by the failure diagnosis. A select control device for an electronically controlled automatic transmission, comprising: a backup unit that performs a backup process that is considered to end the select operation later. (Operation) In the present invention, the state of the select switch is diagnosed by a specific diagnostic means, and as a result, when the select switch is abnormal, an appropriate backup process is performed. That is, the select switch detects the gear select position. However, if there is an abnormality in the select switch, the gear select position cannot be detected, so that automatic gear shifting becomes impossible. In order to avoid such a situation, an appropriate backup process is performed so that the operation can be performed when the select switch is abnormal. (Example) Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a select control device of an electronically controlled automatic transmission according to the present invention, and FIG. 2 is a flowchart showing a flow of processing of the select control device. In FIG. 1, operation signals OP1 to OP4 for operating select switches SW1 to SW4 are applied to one terminal of the AND circuits 1-1 to 1-4, and a mask from the processor 2 is applied to the other terminal. The signals MK1 to MK4 are added. Mask signal MK1 from processor 2
MK4 are set to “1” when there is no abnormality in the select switches SW1 to SW4, and the select switches SW1 to SW4 are set to “1”.
No mask processing is performed on SW4 through SW4, but when any one of the select switches SW1 through SW4 is short-circuited, the select switch is masked, and the corresponding mask signal becomes "0". These AND circuits 1-1
Outputs of the corresponding select switches SW1 to SW
In addition to W4, it controls the operation of select switches SW1 to SW4. The processor 2 controls the operation of the select control device, and its control program is stored in a read-only memory (ROM) 3. Also, status register 4
Is an 8-bit register that stores the states of the select switches SW1 to SW4. When the select switch SW1 is ON, "1" is stored in the least significant bit N1. Similarly, when SW2, SW3, and SW4 are ON, "1" is stored in bits N2, N3, and N4. I have. Since the upper 4 bits of the status register 4 are not used, "0" is stored. The status register 4 is connected to the processor 2, and the processor 2 diagnoses open / short of the select switches SW1 to SW4 according to the contents of the status register 4,
In the event of a failure, backup processing is performed. That is, when it is determined that the select switches SW1 to SW4 are open, a trial of the select control is performed again, and as a result, when the target select position is selected, the process shifts to the shift control. When it is determined that the select switches SW1 to SW4 are short-circuited, the processor 2 generates the above-described mask signal for the short-circuited select switch among the switches SW1 to SW4, that is, for the AND circuit, and selects the select signal. The operation of the switch is stopped. The operation of the select control device having the above configuration will be described with reference to the flowchart of FIG. FIG. 2 shows a flow of a self-diagnosis of an open mode failure and a short mode failure and a flow of its backup processing. Prior to starting this processing, the time required for the select valve to operate to the select position is initially set as the set time of the select valve. Also,
The number of retries for select control is set in advance as a set value. In the figure, in step S1, a select target position is first determined. Next, in step S2, the select valve is turned ON. As a result, the gear select actuator is driven, and the select position can be detected by the select switches SW1 to SW4. Next, in step S3, it is checked whether or not the select switch corresponding to the target position has been turned ON. When the select switch is turned on, "1" is decremented from the open error counter, and the counter is counted down to "0" in a normal state (step S7). Further, since the shift position can be normally shifted by detecting the select position, the process proceeds to step S4, and shift control or neutral control is performed. If the select switch is not turned on in step S3, it is determined whether or not the set time of the select valve has elapsed. If the set time has not elapsed, step again to wait for the set time to elapse.
Return to S1. If it is determined in step S5 that the set time of the select valve has elapsed, the process proceeds to step S6 to check whether all the select switches SW1 to SW4 are OFF. Then, the select switches SW1 to S
If any of W4 is ON, it is determined that a position other than the target select position has been selected, and the process returns to step S1 to retry the select control. In step S6, when all the select switches SW1 to SW4 are OFF, the process proceeds to step S8, and the open error counter is increased by "1". Next, the process proceeds to the switch S9. In step S9, when the open error counter counts up or down in step S8 or S7, it is determined whether or not the count is greater than a set value. When the open error counter is larger than the set value, the select switch does not turn ON even if the predetermined number of retries is repeated, so that the process proceeds to step S10 to perform the neutral control. When the open error counter is smaller than the set value in step S9,
In order to retry select control, step S1
At 1, a set time is selected at a predetermined select position, and the process returns to step S1. Thus, in steps S1 to S11, the self-diagnosis of the open mode failure and the backup processing thereof are performed. That is, when an open mode failure occurs, the diagnosis is performed during retry of the select control, and the target select switch is
When the selection switch is not turned on and the other select switches are not turned on, the selection control is retried. When the number of times of the retry is equal to or more than a predetermined set value, the open failure switch can be detected. Also, the target select switch does not turn on, and one of the other select switches turns on.
In the case of (1), retry of the select control is performed to prevent a misshift. At this time, the diagnosis of the open failure is not performed. (Effects of the Invention) As described above, according to the present invention, since the backup process for diagnosing the open mode failure of the select switch and performing a retry at the time of abnormality is performed, the vehicle is stopped even if the select switch becomes abnormal. The safety can be ensured without causing the problem.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a system configuration diagram of a select control device of an electronically controlled automatic transmission according to the present invention; FIG. 2 is a flowchart showing a flow of select control processing of the electronically controlled automatic transmission; The figure is a configuration diagram of a conventional electronically controlled automatic transmission control system,
FIG. 4A is an explanatory diagram showing a relationship between a gear position and a select switch, and FIG. 4B is a schematic configuration diagram of a stroke sensor. 1-1, 1-2, 1-3, 1-4 ... AND circuit, 2 ... Processor, 3 ... ROM, 4 ... Status register, SW1, SW2, SW3, S
W4: Select switch, MK1, MK2, MK3, MK4: Mask signal.

Claims (1)

(57) [Claims] In an electronically controlled automatic transmission including a plurality of select switches corresponding to each gear position for detecting a gear select position and a diagnosis unit for diagnosing a state of each of the select switches, a state of each of the select switches is detected. If none of the select switches is on, a failure diagnosis means for diagnosing a failure, and if the diagnosis result of the failure diagnosis indicates that the select switch is faulty, the selection operation process and the diagnosis of the state of the select switch are performed a plurality of times. And a backup means for performing a backup process that considers the end of the select operation after the selection is performed.