JPH0514823B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a backup control device for an automatic transmission for a vehicle.

(Prior Art) In recent years, electronic automatic transmissions have been developed that use an electronic control unit composed of a microcomputer to determine the optimum gear position based on outputs from various sensors installed in the vehicle and perform gear change control. ing.

In this type of electronic automatic transmission, a shift map corresponding to the vehicle speed and the amount of accelerator pedal depression is prepared in advance, and the optimum gear is searched from the shift map based on the vehicle speed and the amount of accelerator pedal depression detected by a sensor. be.

Therefore, since the vehicle speed signal is an essential factor in the electronic automatic transmission system, even if the vehicle speed signal is lost due to a failure of the vehicle speed sensor, for example, In the vehicle speed measurement method for electronic automatic transmissions, a proposal has been made to convert each rotation signal of the transmission input shaft rotation speed, engine rotation speed, and drive shaft rotation speed into vehicle speed, and to determine the vehicle speed from these vehicle speeds using majority logic. ing. However, when the transmission is in neutral, the engine speed is independent of the vehicle speed.
Unable to determine vehicle speed.

However, even in such a case, the vehicle speed calculated from the engine rotational speed etc. is maintained as the previous backup vehicle speed even when the select lever is set to neutral and the gear is set to neutral. This is to prevent the engine and transmission from overrunning if the select lever is accidentally set to neutral during backup driving and then reselected to the driving range.

(Problem to be Solved by the Invention) However, if the select lever is set to neutral while driving and coasts to a stop, the backup vehicle speed will be maintained and the vehicle will restart, and the vehicle will return to the saved vehicle speed. At the same time, a gear change operation is performed, and engine rotation matching control is also performed. This causes the engine to rev up for a moment. This momentary engine revving is
This may cause the driver and passengers to feel extremely anxious, or may cause a temporary shock.

Therefore, an object of the present invention is to prevent the engine from revving up momentarily by prohibiting engine rotation adjustment when the select lever is in the neutral position before shifting when the vehicle speed sensor is malfunctioning or the select lever is in the neutral position. An object of the present invention is to provide a backup control device for a vehicle equipped with a transmission.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention includes an electronic control device that determines the optimum gear position according to the vehicle speed and the amount of depression of the accelerator pedal. In automatic transmissions for vehicles that shift gears and perform engine rotation matching control when shifting to the optimal gear, if the sensor that detects the vehicle speed fails, the transmission input shaft rotation speed or engine rotation speed A backup means is provided for calculating the vehicle speed from the vehicle speed, and when the backup means is used for control, engine rotation matching control is prohibited if the select lever is in neutral position before shifting. A backup control device for a vehicle automatic transmission is provided.

(Function) When the vehicle speed sensor is malfunctioning and the vehicle speed backs up at the speed calculated from the engine speed, tire circumference, and total reduction ratio, the present invention allows the vehicle to coast by setting the select lever to neutral while driving. When stopping, normal gear shifting operations
Since the operation from shifting out to shifting in is performed continuously, the back-up vehicle speed immediately before the start of the gear shifting operation is held, and the target rotation speed for engine rotation matching control in the next gear is calculated from that value. This is a backup control device for an automatic transmission for a vehicle that prohibits engine rotation matching only during a gear change operation associated with selection from neutral to travel range.

(Example) Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic configuration diagram of an embodiment of a backup control device for an automatic transmission for a vehicle according to the present invention, and FIG. 2 is a flowchart of the control according to the present invention.

In FIG. 1, an engine 1 includes a throttle valve for controlling the amount of intake gas (air or mixture), and is equipped with a flywheel 1a. Reference numeral 2 represents a clutch body, which is composed of a well-known friction clutch and has a release lever 2a, and 3 represents a clutch actuator, whose piston rod 3a is connected to the release lever 2a in order to control the amount of engagement of the clutch body 2. It is what drives the. 4 is a hydraulic mechanism, and 5 is a transmission actuator. 6 is a synchronized mesh transmission,
It is driven by the transmission actuator 5 to perform gear shifting operations, and includes an input shaft (input shaft) 6a connected to the clutch 2, an output shaft (drive shaft) 6b, and a gear position sensor that detects the gear position (gear position). 6c.

7 is a select lever which is operated by the driver and selects "N" range (neutral position), "D" range (automatic shift), "1" range (1st speed), "2" range (2nd speed), "3" range (1st, 2nd, 3rd speed automatic shifting) and "R" range (reverse) can be selected by the lever position, and the selection signal SP indicating the selected range is sent by the select sensor 7a. is output by . 8a is a rotation sensor for detecting the rotation speed of the input shaft 6a, and 8b is a vehicle speed sensor for detecting the vehicle speed from the rotation speed of the drive shaft 6b. connected to. Reference numeral 10 denotes an engine rotation sensor, which is used to detect the rotation speed of the engine 1 by detecting the rotation speed of the flywheel 1a.

The electronic control device 9 is composed of a microcomputer, and includes a processor 9a that performs arithmetic processing;
A read-only memory (ROM) 9b that stores a control program for controlling the transmission 6 and the clutch 3, an output port 9c, an input port 9d, and a random access memory (RAM) 9e that stores calculation results and the like. It is composed of a data bus (BUS) 9f that connects these. The output port 9c is connected to the clutch actuator 3, the hydraulic mechanism 4, and the transmission actuator 5,
Outputs drive signals CDV, PDV, and ADV to drive these.

On the other hand, the input port 9d is connected to the clutch actuator 3, various sensors 6c, 7a, 8a, 8b, 1
0, an accelerator pedal 11, and a brake pedal 12, which will be described later, and receive detection signals from these pedals. The accelerator pedal 11 has a sensor 11a (potentiometer) that detects the amount of depression thereof,
The brake pedal 12 has a sensor 12a (potentiometer) that detects the amount of depression.

Next, the control operation procedure in the present invention will be explained with reference to FIG.

First, the select lever signal and vehicle speed sensor signal are read, and the vehicle speed sensor is diagnosed (steps S1, S2, and S3).

Then, it is determined whether the vehicle speed sensor is normal or malfunctioning (step S4), and if it is malfunctioning, the vehicle speed is backed up (step S5) and the vehicle speed sensor failure flag is turned ON. Further, when the vehicle speed is normal, the vehicle speed sensor flag is turned OFF (step S7).

Next, the select lever position is N (neutral).
If it is not neutral, it is determined whether the previous select lever position was neutral (step S9).

When it is neutral, the select flag from neutral is turned ON (step S10), and when it is not neutral, or when it is determined to be neutral in step S8, the select flag from neutral is turned OFF (S11).

Then, optimum gear stage determination processing is performed (step S12).

Next, it is determined whether the current gear is the optimum gear (step S13), and if it is the optimum gear, clutch control and load control using the accelerator are performed (steps S14, S15).

However, when the gear position is not optimal, the gear change operation (clutch disengagement, shift removal, selection, shift engagement, etc.)
clutch engagement) is performed (step S16).

Next, check whether the vehicle speed sensor failure flag is ON (failure).
It is determined whether it is OFF (normal) (step S17), and if there is a failure, the select flag from the neutral is ON.
(select operation from neutral) or OFF (select other than neutral) is determined (step S18). When ON, rotation matching is prohibited; when OFF in step S17,
When it is OFF in S18, engine rotation matching control is performed (step S19).

(Effects of the Invention) As described above in detail, the present invention is applicable only to the gear shift operation associated with selection from the select lever neutral to the driving range where the vehicle state becomes discontinuous during back-up driving.
Since the engine rotation matching control is prohibited when the select lever position before shifting is in neutral, momentary engine revving can be prevented even when the vehicle is coasting to a stop.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a backup control device for an automatic transmission for a vehicle according to the present invention, and FIG. 2 is a diagram showing a flow chart of the control according to the present invention. 1...Engine, 6...Transmission, 8a, 8b...
...sensor, 9...electronic control unit, 10...sensor, 11...accelerator pedal.

Claims (1)

[Claims] 1. An automatic transmission for a vehicle that has an electronic control device that determines the optimum gear according to the vehicle speed and the amount of accelerator pedal depression, and that shifts to the optimum gear. In a vehicle that performs control, a backup means is provided that calculates the vehicle speed from the transmission input shaft rotation speed or engine rotation speed when the sensor that detects the vehicle speed fails, and when controlling using the backup means, the shift A backup control device for an automatic transmission for a vehicle, characterized in that it is configured to prohibit engine rotation matching control when a front select lever is in a neutral position.