JPH03194262A - Shift control device for automatic transmission - Google Patents

Abstract

PURPOSE:To perform a highly accurate fail-safe control by estimating a throttle valve opening from an engine load, detected from the other engine operative condition and an engine speed, to perform a speed change control, when a throttle valve opening detecting means is in abnormality. CONSTITUTION:An automatic transmission is controlled to its speed change position by a speed change control means being based on a detected throttle valve opening and a car speed by a car speed detecting means, when a throttle valve opening detecting means is normal. When abnormality of the throttle valve opening detecting means is detected, the throttle valve opening is estimated by a throttle valve opening estimating means being based on an engine load except the throttle valve opening, detected by an engine load detecting means, and an engine speed detected by an engine speed detecting means, and the speed change position of the automatic transmission is controlled by the speed change control means being based on the car speed. Thus, a highly accurate fail-safe control can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a device for controlling the shift position of an automatic transmission.

<Prior Art> Conventionally, vehicles equipped with an automatic transmission with a torque converter are known to shift gears according to a preset shift pattern based on vehicle speed and throttle valve opening. (Refer to Japanese Utility Model Application Publication No. 194231/1983, etc.).

In such conventional shift control, when an abnormality occurs in the throttle sensor that detects the throttle valve opening, if the shift control is performed based on the signal from the throttle sensor, the shift will be performed to a position that is far away from the requested shift position. It will be controlled.

Therefore, the throttle valve opening information other than the throttle sensor is based on the idle switch, which is ON at low load below a predetermined opening, and the ON/OFF state of the full switch, which is ON at high load above a predetermined opening. As shown in Figure 7, low load and medium load.

Fail-safe control is performed to switch to three high-load stages.

<Problems to be Solved by the Invention> However, with the conventional fail-safe control as described above, it is not possible to perform linear speed change control according to changes in throttle valve opening as in normal conditions, especially in the medium load range. Performance was deteriorating.

The present invention has been made in view of such conventional problems, and when an abnormality occurs in the thrower 1 to senza, the throttle valve opening is estimated from information on the engine operating state other than the throttle sensor, and the estimated throttle valve opening is It is an object of the present invention to provide a speed change control device for an automatic transmission that has enhanced fail-safe function by performing speed change control based on the opening degree.

<Means for Solving the Problem> Therefore, as shown in FIG. 1, the present invention includes a throttle valve opening detection means, a vehicle speed detection means, and a speed change method of an automatic transmission based on the throttle valve opening and the vehicle speed. A shift control device for an automatic transmission comprising a shift control means for controlling a position,
An abnormality detection means for detecting an abnormality in the throttle sensor, and an engine load detected by the engine load detection means for detecting engine load other than the throttle valve opening when the throttle sensor is detected to be abnormal, and engine rotation. A throttle valve opening estimating means is provided for estimating the throttle valve opening based on the engine rotational speed detected by the speed detecting means, and when the throttle sensor is abnormal,
The configuration is such that the shift position of the automatic transmission is controlled based on the estimated throttle valve opening and vehicle speed.

<Operation> When the throttle valve opening detection means is normal, the gear change control means controls the automatic transmission based on the throttle valve opening detected by the step valve opening detection means and the vehicle speed detected by the vehicle speed detection means. Controls the gear shift position.

Further, when the abnormality detection means detects an abnormality in the throttle valve opening detection means, the engine load other than the throttle valve opening detected by the engine load detection means,
The throttle valve opening detection means estimates the throttle valve opening based on the engine rotation speed detected by the engine rotation speed detection means.

At the time of the abnormality, the shift control means controls the shift position of the automatic transmission based on the estimated throttle valve opening and the detected vehicle speed.

<Example> Embodiments of the present invention will be described below based on the drawings.

In FIG. 2 showing the configuration of an embodiment, an automatic i-speed 1a consisting of a 1-lux converter and a transmission is shown.
In order to control the working hydraulic pressure of the front clutch, rear clutch, brake band 2, ROHM reverse brake, one-way clutch, etc., the transmission is installed in the hydraulic pressure passage leading to these, and controls the valve opening duty. Solenoid valves 2A to 2E are provided to control the hydraulic pressure.

On the other hand, a throttle valve (not shown) installed in the intake passage of the engine includes a throttle sensor 3 as a throttle valve opening detection means, an idle switch 4 that is turned on at an idle position, and a full switch 5 that is turned on at a high load position. is provided. Further, a vehicle speed sensor 6 as vehicle speed detection means is provided near the output shaft of the transmission, and a gear position sensor 7 for detecting a gear position G (shift position) is provided in the transmission.

In the control unit 8, an engine control CPU 81 and an automatic transmission control CPU 82 are connected via a dual port RAM 83 so that data can be communicated with each other. And CPU for engine control i11
81 includes a throttle valve opening TVO signal from the throttle sensor 3, ON/OFF signals of the idle switch 4 and full switch 5, and a vehicle speed signal from the vehicle speed sensor 6.
, an air flow meter 9 that detects the intake air flow rate Q in addition to the gear position signal G from the gear position sensor 7. A signal from a crank angle sensor 10 or the like that detects the engine rotational speed N is input.

On the other hand, the automatic transmission control CPU 82 receives the throttle valve opening TVO signal, the ON/OFF signals of the idle switch 4 and full switch 5, the vehicle speed signal ■, the gear position signal G, and the intake air flow rate Q via the dual port RAM 83. In addition to the input, the engine rotation speed signal N from the crank angle sensor 1.0 is also directly input.

Then, when the throttle valve opening degree 3 is normal, the automatic transmission CPU 82 determines the transmission shift point based on the throttle valve opening degree ``VO'' and the vehicle speed ■, and opens each of the solenoid valves 2A to 2E. Shift control is performed by controlling the valve duty, but when the throttle sensor 3 is abnormal, the throttle valve opening is estimated based on the intake air flow JilQ and the engine rotational speed N, and the estimated throttle valve opening is Shift control is performed based on TVO' and vehicle speed V.

Shift control by the automatic transmission CPIJ 82 will be described below with reference to the flowchart shown in FIG. 3.

In step (denoted as S in the figure) 1, the current throttle valve opening TVO1 vehicle speed ■, gear position G, and ON/OFF of the idle switch and full switch.

Read the detected values of intake air flow rate Q and engine rotation speed N.

In step 2, it is determined whether the throttle sensor 3 is abnormal. For example, when the idle switch 4 is ON, the throttle valve opening TVO is larger than the value corresponding to a low-quality load, or when the full switch 5 is ON, the throttle valve opening TVO is larger than the value corresponding to a high load. If the value is smaller than the value, it can be determined that there is an abnormality. The function of step 2 corresponds to the abnormality detection means.

When the throttle sensor 3 is determined to be normal in step 2, the process proceeds to step 3, where a shift pattern is stored in the ROM based on the throttle valve opening TVO detected by the throttle sensor 3 and the vehicle speed. ■
(see FIG. 4), reads the gear position to be shifted, compares it with the current gear position G, and determines whether to shift up, downshift, or maintain the current state, and performs speed change control.

Further, when it is determined in step 2 that the throttle sensor 3 is abnormal, the process proceeds to step 4, and the intake air flow ff
The throttle valve opening TV○' is estimated from a map table stored in the ROM based on 1Q and the engine rotational speed N (see FIG. 6).

In this case, the air flow meter 9 that detects the intake air flow rate Q as a twin engine load other than the throttle valve opening constitutes an engine load detecting means, and the function of step 4 constitutes a throttle valve opening 111 determining means.

Then, the process proceeds to step 5, and based on the estimated throttle valve opening degree TVO' and vehicle speed ■, the shift pattern ■ (see Fig. 5) stored in the ROM is used to select whether to shift up, down, or maintain the current state. The system determines this and controls the gear shift.

Here, the functions of step 3 and step 5 and the solenoid valves 2A to 2E constitute a speed change control means.

In addition, in shift pattern ■, the estimated throttle valve opening T
When VO' is above a certain level, the intake air flow rate Q reaches a saturated state, so the shift point is set to change based only on the vehicle speed, but the same shift pattern as in normal times may be used.

Further, the abnormality determination of the throttle sensor 3 is performed by first estimating the throttle valve opening TVO' and then estimating the estimated opening TVO'.
Opening degree T detected by throttle sensor 3 with respect to VO'
A configuration may be adopted in which it is determined that there is an abnormality when the VO is significantly different, and in the event of an abnormality, the speed change control may be performed directly using the estimated opening degree TV○'.

In addition to the intake air flow rate Q, the engine load parameters used to estimate the throttle valve opening TVO' include the basic fuel injection amount TP calculated in the engine's fuel injection amount setting routine, and the intake pressure q (especially the intake air flow rate Q). It is also possible to use a system that calculates the fuel injection amount by detecting pressure and is highly useful.

<Effects of the Invention> As explained above, according to the present invention, when the throttle valve opening detection means is abnormal, the throttle valve opening is estimated from the engine load and engine rotation speed detected from other engine operating conditions. Since the configuration is such that shift control is performed at 0, highly accurate fail-safe control can be performed.

[Brief explanation of drawings]

FIG. 1 is a Zoroku diagram showing the configuration of the present invention, and FIG. 2 is a
FIG. 3 is a flow chart showing the shift control routine of the embodiment of the present invention; FIG. 4 is a diagram showing the shift pattern I used in the embodiment; FIG. is a diagram showing the same shift pattern ■, and FIG.
FIG. 7 is a diagram showing the characteristics of the throttle valve opening degree estimated based on the intake air flow rate and the engine rotational speed, and FIG. 7 is a diagram showing the shift pattern during conventional fail-safe control.

Claims (1)

[Claims] In a shift control device for an automatic transmission, the shift control device includes a throttle valve opening detection means, a vehicle speed detection means, and a shift control means for controlling a shift position of the automatic transmission based on the throttle valve opening and the vehicle speed. abnormality detection means for detecting an abnormality in the throttle sensor; engine load detected by the engine load detection means for detecting engine load other than the throttle valve opening when the throttle sensor is detected to be abnormal; and engine rotation speed detection. A throttle valve opening estimating means is provided for estimating the throttle valve opening based on the engine rotational speed detected by the means, and when the throttle sensor is abnormal, the throttle valve opening is automatically estimated based on the estimated throttle valve opening and the vehicle speed. 1. A shift control device for an automatic transmission, characterized in that it is configured to control a shift position of a transmission.