JPS6262045A - Electronic automatic transmission - Google Patents

Abstract

PURPOSE:To enable an automatic transmission control to be performed in no relation to a trouble of a throttle sensor, by estimating a throttle opening from an engine speed and an intake pipe negative pressure and determining a target shift position from said estimated opening and a car speed, when the throttle sensor is in trouble. CONSTITUTION:At normal time when a trouble is not detected in a throttle sensor 1 by a trouble detecting means 8, a switching means 9 selects the first shift position determining means 3, and a device, determining a target shift position from outputs of the throttle sensor 1 and a car speed sensor 2 to be added to a shift control means 12, performs a normal transmission control. On the contrary, when a trouble of the above described sensor 1 is detected, the switching means 9 selects the second shift position determining means 7. And the device, obtaining an estimated throttle opening by a calculating means 6 from outputs of an engine speed sensor 4 and an intake pipe negative pressure sensor 5 and determining a target shift position from the estimated throttle opening and the output of the car speed sensor 2, controls an actuator 11 in accordance with said target shift position.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electronic automatic transmission, and more particularly to an electronic automatic transmission that is capable of automatically changing gears even if a throttle sensor fails.

Generally, an electronic automatic transmission device controls a shift position of a transmission based on a throttle opening detected by a throttle sensor and a vehicle speed detected by a vehicle speed sensor. Therefore, if either the throttle sensor or the vehicle speed sensor fails, automatic gear shifting will not occur at all or will occur abnormally.Therefore, even if the throttle sensor or vehicle speed sensor fails, it is important to ensure that gear shifting operations occur normally. A fail-safe mechanism is required to ensure that

[Conventional technology]

Conventional fail-safe mechanisms of this type include two systems of vehicle speed sensors, a main system and a sub system, and when the main system fails, the sub vehicle speed sensor is used to continue control. However, only one throttle sensor has been provided due to limitations in mounting space and cost.

[Problem that the invention seeks to solve]

Therefore, if the thrower sensor fails, there is a problem in that appropriate automatic gear shift control cannot be performed.

The present invention has been made in view of these circumstances,
The purpose is to provide an electronic automatic transmission device that can perform automatic transmission control even if a throttle sensor fails.

[Means for solving problems]

In order to achieve the above object, the present invention uses a throttle sensor 1, a vehicle speed sensor 2, a vehicle speed detected by the vehicle speed sensor 2, and a throttle opening detected by the throttle sensor 1, as shown in FIG. a first shift position determining means 3 that determines a target shift position based on the engine rotation speed sensor 4; an intake pipe negative pressure sensor 5; and intake pipe negative pressure and engine rotation detected by the intake pipe negative pressure sensor 5. Throttle opening estimating means 6 estimates the throttle opening at that time from the engine speed detected by the speed sensor 4, and the estimated throttle opening estimated by the throttle opening estimating means 6 and the vehicle speed sensor 2. a second shift position determining means 7 that determines a target shift position based on the detected vehicle speed; a failure detecting means 8 that detects whether or not there is a failure in the throttle sensor 1;
a selection means 9 for selecting a shift position to be used for control from among the shift position determined by the first shift position determination means 3 and the shift position determined by the second shift position determination means 6 according to the detection result of the failure detection means 8; and a shift control means 12 for controlling an actuator 11 for driving the transmission so that the shift position of the transmission 10 matches the shift position selected by the selection means 9.

[Effect]

During a period in which a failure or abnormality of the throttle sensor 1 is not detected by the failure detection means 8, the selection means 9 adds the target shift position of the first shift position determination means 3 to the shift control means 12, so that normal transmission control is performed. When a failure or abnormality of the throttle sensor 1 is detected by the failure detection means 8, the selection means 9
is switched, and the actuator 11 is controlled by the target shift position of the second shift position determining means 7.

〔Example〕

FIG. 2 is a block diagram showing an example of the hardware configuration of the embodiment of Akira Kibai, in which 20 is an engine, 21 is a transmission, 2
2 is an actuator for changing the speed of the transmission 21, and 23 is a controller. The rotation speed of the engine 20 is detected by an engine rotation speed sensor 24 such as a crank angle sensor, the opening degree of the throttle valve 25 is detected by a throttle sensor 35, the negative pressure in the intake pipe 26 is detected by a negative pressure sensor 27, Each is input to the input ink face 28 of the controller 23.

Further, a vehicle speed sensor 29 that detects the vehicle speed of the automobile and a brake switch 30 that is turned on when the brake is stepped on are provided, and signals from these are also input to the ink face 28.
is input.

The controller 23 includes a microprocessor (MPU) 31, an input ink face 2B connected thereto, and an A/D converter 32. It consists of a memory 33 including ROM, RAM, etc., and an interface 34. The MPU31 is
It operates according to the program stored in the memory 33, takes in various signals input to the input ink face 28 directly or after converting them into digital quantities with the A/D converter 38, performs predetermined processing, and generates a shift control signal a. -C to the actuator 22 via the output ink face 34. Among the shift control signals sent from the output interface 34, signals a and b are signals for turning on and off the shift solenoid of the actuator 22, and signal C is a signal for lock-up control. The actuator 22 switches the shift solenoid according to the on/off states of the signals a and b, and changes the shift position of the transmission 21. Further, the lock amplifier release 1 operation is performed in accordance with the level of the lock-up signal C.

FIG. 3 is a flowchart showing an example of the processing of the MPU 31, and 81 to Sll indicate each step.

The operation of this embodiment will be described below with reference to the drawings.

MPIJ31 executes the process shown in Figure 3 at predetermined intervals, and when the execution cycle comes, it first slows down.
Determine whether or not the sensor 35 is out of order (Sl)
. Various methods can be considered to determine this failure, and the present invention is not particularly limited to such methods. A method is adopted in which a failure is determined when the throttle opening signal does not change in the fully closed direction even though the brake is depressed.

If it is determined in step S1 that the throttle sensor 35 is not malfunctioning, normal operation is performed. That is,
First, the throttle opening T is determined from the output of the throttle sensor 35.
After reading A, calculate the vehicle speed sp based on the output of the vehicle speed sensor 29.32. S3) Next, the target shift position is determined by referring to the map in the memory 33 using the second throttle opening TA and vehicle speed sP as parameters (s4). Then, when it is determined that a shift is necessary by comparison with the current shift position of the transmission 21 (S5),
A shift control signal a "-" C is sent from the output ink phase 34 to the actuator 22 according to the target shift position.
to perform a shift operation (S6).

On the other hand, if it is determined that the throttle sensor 35 is out of order for some reason, the target shift position is determined by the following processing from step 87 to Sll.

First, the engine speed NE is calculated based on the output of the engine speed sensor 24, and the negative pressure gate of the intake pipe 26 is read from the output of the negative pressure sensor 27 (37.S8). Then, the current throttle opening degree is estimated from this intake pipe negative pressure PM and the engine speed NE (S9). The estimated throttle opening DTA is calculated by utilizing the fact that the throttle opening is approximately proportional to the intake pipe negative pressure under a constant engine speed.

In Figure 4, the horizontal axis is the intake pipe negative pressure PM, and the vertical axis is the engine speed NE, and the region defined by both values is divided into four in the example shown in the figure, and one estimated throttle control is assigned to each division. The opening degrees DTA + to DTA 4 are assigned. Such a map is stored in the memory 33, and M P
U31 performs step S7. The estimated throttle opening degree DTA is calculated by referring to the above map using the engine speed NE and intake pipe negative pressure PM determined in S8 as parameters.

Now, when the estimated throttle opening DT^ is calculated, M
Next, P U31 calculates the vehicle speed SP in the same manner as step S3 (510), and uses this calculated vehicle speed SP and step S
The target shift position is determined by referring to the map dedicated to the estimated throttle opening stored in advance in the memory 33 using the estimated throttle opening DTA calculated in step 9 as a basis.
Sll).

FIG. 5 is a diagram showing an example of a map dedicated to estimated throttle opening, in which the horizontal axis represents the vehicle speed SP and the vertical axis represents the estimated throttle opening DTA. Indicates the shift to speed darkness value. Similar shift darkness values are also set for other shifts, such as from second to third gear. Note that the map used to calculate the target shift position when the throttle sensor is normal is the vehicle speed SP and estimated throttle opening 1) T.
Although the estimated throttle opening degree DTA may be determined by generating a parameter, the estimated throttle opening degree DTA is only an estimated value and is not very accurate, so it is desirable to prepare a dedicated map that takes this point into consideration.

Once the target shift position is determined in step Sll, the rest is step S5. The process moves to S6, and the shift position of the transmission 21 is controlled to become the target shift position.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various other additions and changes are possible. For example, it is free to use the intake pipe negative pressure at the time when the engine speed becomes approximately constant when calculating the estimated throttle opening.

〔Effect of the invention〕

As explained above, the present invention takes advantage of the fact that the current throttle opening can be estimated from the engine speed and the intake pipe negative pressure, and when the throttle sensor fails, the throttle opening can be estimated from the engine speed and the intake pipe negative pressure. Since the opening is estimated and the target shift position is determined from this and the vehicle speed, even if the throttle sensor fails, it is possible to continue the automatic shift control of the transmission to a degree sufficient for practical use. This has the effect of ensuring sufficient driving performance such as evacuation driving.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the configuration of the present invention, FIG. 2 is a block diagram of main parts showing an example of the hardware configuration of an embodiment of the present invention, FIG. 3 is a flowchart showing an example of processing of the MPU 31, and FIG. FIG. 5 is a diagram showing an example of a map for calculating the estimated throttle opening, and FIG. 5 is a diagram showing an example of a map for calculating the target shift position from the estimated throttle opening and the vehicle speed. 20 is an engine, 21 is a transmission, 22 is an actuator, 23 is a controller, 24 is an engine speed sensor, 25 is a throttle valve, 26 is an intake pipe, 27 is a negative pressure sensor, 28
is an input interface, 29 is a vehicle speed sensor, 30 is a brake switch, 31 is an MPLJ, 32 is an A/D converter,
33 is a memory, 34 is an output ink face, and 35 is a throttle sensor. .

Claims (1)

[Scope of Claims] A throttle sensor; a vehicle speed sensor; and a first shift position determination method for determining a target shift position based on the vehicle speed detected by the vehicle speed sensor and the throttle opening detected by the throttle sensor. means, an engine rotational speed sensor, an intake pipe negative pressure sensor, and detecting the throttle opening at that time based on the intake pipe negative pressure detected by the intake pipe negative pressure sensor and the engine rotational speed detected by the engine rotational speed sensor. a second shift position that determines a target shift position based on the estimated throttle opening estimated by the throttle opening estimation means and the vehicle speed detected by the vehicle speed sensor; determining means; failure detecting means for detecting the presence or absence of a failure in the throttle sensor; and determining the shift position determined by the first shift position determining means and the determined shift position by the second shift position determining means in accordance with the detection result of the failure detecting means. a selection means for selecting a shift position to be used for control from among the determined shift positions; and a shifter for controlling an actuator for driving the transmission so that the shift position of the transmission matches the shift position selected by the selection means. An electronic automatic transmission device characterized by comprising a control means.