JPH02199239A - Abnormality detecting device for traction control system - Google Patents

Abstract

PURPOSE:To prevent traction control from being deteriorated in performance by closing the second throttle valve to the extent of its critical limit tentatively at the time of engine starting, and thereby judging that the control system of No.2 throttle valve is abnormal when the detected critical opening valve on the entirely closing side is equal to or more than a set value. CONSTITUTION:A traction control system forces No.2 throttle valve to be reduced in opening when the slip in driving takes place at wheels during running so that engine output will be reduced much more than the value corresponding to the stroke of an accelerator pedal footing. And an engine start detecting means tentatively closes the second throttle valve to the extent of its critical limit via a closing means, detecting the critical opening on the entirely closing side at this time by the detecting means at the time of engine starting wherein no traction control is required and engine output may be held minimum so that the second throttle valve is judged to have been abnormal by an abnormality judging means when the aforesaid detected value is equal to or more than a set value. Thus, abnormality in the control system can be detected every engine starting, and a deterioration in traction control performance can thereby be prevented by accurately storing the entirely closed position with use of monitoring of the critical opening on the entirely closing side.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an abnormality detection device for a traction control device that prevents wheel drive slip (wheel spin).

(Prior Art) A vehicle can travel by driving wheels with an engine whose output is determined by a throttle valve that is linked to an accelerator pedal. Conventionally, as a traction control device for preventing drive slip of the wheels during driving, a second throttle valve is installed in series with the throttle valve, as described in Japanese Patent Application Laid-open No. 61-60331 and Japanese Patent Application Laid-open No. 129432-1983. There is a system in which a drive slip is prevented by reducing the opening of the second throttle valve to reduce the engine output when a drive slip occurs.

(Problem to be Solved by the Invention) In such a traction control device, the second throttle valve remains fully open except when the wheels are slipping during driving, and since driving slips rarely occur, the second throttle valve remains fully open at the fully open position. may become stuck or, if not stuck, be unable to close in a position that prevents drive slip. Conventionally, there is no device for detecting such an abnormality, and the actual situation is that the abnormality is only known when a wheel drive slip occurs and it becomes impossible to prevent it. In addition, conventionally, the output value of the throttle opening sensor corresponding to the fully closed position of the second throttle valve is stored in the memory of the controller, and when drive slip occurs, the second throttle valve is closed according to the slip state, and the slip is eliminated. When the condition is large, the second throttle valve is driven until the throttle opening sensor outputs a fully closed position value.

However, if the sensor changes over time, the accurate fully closed position cannot be determined and the second throttle valve cannot be closed to its original fully closed position, resulting in deterioration of traction control performance. Furthermore, even if the fully open position is backed up in memory, the memory may be erased due to removal of the battery, etc., and traction control itself may become disabled.

The present invention detects abnormalities by once closing the second throttle valve to its limit and monitoring its fully open limit opening every time the engine is started, and by checking the fully closed position of the second throttle valve. The purpose is to solve the problem.

(Means for Solving the Problems) For this purpose, the abnormality detection device of the present invention, as conceptually shown in Fig. 1, runs by driving the wheels with an engine whose output is determined by a throttle valve linked to an accelerator pedal. In the vehicle, the vehicle is equipped with a traction control device that prevents drive slip by reducing the opening of a second throttle valve in series with the throttle valve when the wheel slips during drive, engine start detection detecting start of the engine. means, a second throttle valve closing means that temporarily closes the second throttle valve to the limit at the time of starting the engine, and a fully open side limit opening detection means for detecting the fully closed side limit opening degree of the second throttle valve; An abnormality determining means is provided which determines that there is an abnormality in the second throttle valve control system when the full-open side limit opening is equal to or greater than a set value.

(Function) After the engine starts, the output of the engine is determined by a throttle valve linked to the accelerator pedal, and this output can drive the wheels and make the vehicle run. When the wheels experience drive slip during running, the traction control device reduces the opening of the second throttle valve to make the engine output smaller than the value corresponding to the accelerator pedal depression amount to prevent the wheels from slipping.

The engine start detection means temporarily closes the second throttle valve to the limit via the second throttle valve closing means when starting the engine without requiring traction control and when the engine output is at a minimum, and at this time, the second throttle valve is fully closed. The limit opening degree is detected by the fully closed side limit opening detection means. The abnormality determining means determines that there is an abnormality in the second throttle valve control system when the fully closed limit opening is equal to or greater than a set value. Therefore, it is possible to check for abnormalities such as the second throttle valve being stuck in the fully open position or being unable to close to the driving slip prevention position every time the engine is started, and to check for abnormalities that cannot be prevented when driving slip occurs. It is possible to solve conventional problems that could only be known until the end. In addition, the fully closed position of the second throttle valve can be rememorized each time the engine is started, and if it becomes necessary to drive the second throttle valve to the fully closed position due to subsequent traction control, it will be newly memorized. The motor second throttle valve is driven until the throttle opening sensor issues an output value corresponding to the fully closed position. As a result, the performance of the traction control may deteriorate due to changes in the sensor over time, or the memory of the fully closed position of the second throttle valve may be erased due to removal of the battery, causing the performance of the traction control to deteriorate or become disabled. There isn't.

(Example) Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a system diagram of a traction control device showing an embodiment of the present invention, in which IL and IR indicate left and right front wheels, 2L and 2R indicate left and right rear wheels, and 3 indicates an engine.

The engine 3 is started by an ignition switch 4, and its output is determined according to the opening degree of a first throttle valve 6 which is linked to an accelerator pedal 5 depressed by the driver. engine 3
The output of the propeller shaft 8 after shifting by the automatic transmission 7 is
and the left and right rear wheels 2L via the differential gear 9,
It is used for 2H driving and allows the vehicle to travel.

When braking the vehicle, the brake units IIL, IIR, 12 of each wheel are activated by depressing the brake pedal 10.
Activate L and 12R.

For traction control, a second throttle valve 13 is provided in series with the first throttle valve 6, and can be independently rotated by a reversible DC motor 14. The direction and amount of rotation of the motor 14 are controlled by a traction controller 15, which controls the F/V converter 1.
6, A/D converter 17, random access memory I
Central processing unit (CPU) with built-in RAM
18, a read-only memory (ROM) 19, and a motor drive circuit 20. Note that the traction controller 15 also serves to turn on an abnormality warning lamp 21 when an abnormality is detected, which will be described later.

The traction controller 15 receives signals from the rotation sensors 22 and 23 that detect the rotational speeds VFL+VFI of the left and right front wheels, and the rotational speed (average rotational speed of the rear two wheels) of the propeller shaft 8 to its P/V converter 16. A signal from the rotation sensor 24 that detects the rotation is input.

-, the F/V converter 16 converts this input information (frequency signal) into voltage and inputs it to the A/D converter 17.

A signal from a rotary encoder (throttle opening sensor) 25 that detects the opening TH of the second throttle valve 13 is further input to this converter 17 .

The A/D converter 17 converts the input analog signal into a digital signal and supplies it to the CPt 118. CPI
J8 also has a signal IG when the engine is started by the ignition switch 4, and an O signal when the brake pedal 5 is depressed.
A signal from the brake switch 26 that turns to N and a signal from the inhibitor switch 27 that detects the selected range of the automatic transmission 7 are input.

The CPIJ 18 executes the control programs shown in FIGS. 3 and 4 stored in the ROM 19 based on the input information, and performs traction control by controlling the motor 4 via the motor drive circuit 20, and performs traction control. It is assumed that an abnormality is detected and the abnormality lamp 21 is turned on.

First, the traction control shown in Figure 3 will be explained.

The control program shown in FIG. 3 performs interrupt processing every fixed time ΔT, and in step 31, the wheel speed VFL, V□
+ Vl is read, and in step 32, the average wheel speed Vp= (Vpt, +V□) of the front two wheels is calculated, and in step 33, the driving speed of the driving rear wheels 2L and 2H is calculated.
/Find the rate S by S=(V RV F)/VF l:. In the next step 34, it is checked whether the drive slip ratio S is a set value of 80 or more and a wheel spin is occurring.

If wheel spin has occurred, the motor 14 is driven in step 35 to reduce the opening of the second throttle valve 13 as described below. In other words, first of all, the second throttle valve 13 necessary to prevent this is determined based on the magnitude of the drive slip rate S.
The opening degree of the second throttle valve is calculated, and this and the current second throttle valve opening degree T are calculated.
By determining and outputting the rotation direction and rotation amount of the motor 14 from the deviation from H, the opening degree of the second throttle valve 13 is reduced to the above-mentioned calculated value, thereby preventing drive slip. Although not shown in FIG. 3, the second throttle valve 13 is driven to the fully closed position and the motor 14 is stopped as necessary.

If wheel spin is not occurring, the opening degree of the second throttle valve 13 is increased by a constant opening degree in step 36,
As a result, the interrupt interval ΔT for this constant opening is
The opening degree of the second throttle valve 13 is increased toward full opening at a speed represented by the ratio of .

At this time as well, the motor 14 stops when the throttle valve 13 is fully opened. FIG. 4 shows a reset routine for abnormality detection that is processed every time the engine start signal IG is input. Clear the RAM data in CPo 18. Next, in steps 42 and 43, it is checked whether the brake switch 26 is in the ON state and the selected range of the automatic transmission 7 detected by the inhibitor switch 27 is the parking (P) range. When the engine is started, the brake is in operation, and the P range is selected, traction control is not performed and the engine output is sufficient at the lowest level, so the second throttle valve 13 is fully closed and the operating system is used for abnormality determination. There is no problem even if you test the operation,
Check flag C to indicate this in step 44.
Set HKFLG to 1. Note that steps 42 and 43
If the condition is not satisfied, control is returned to step 42 and the above loop is repeated until the condition is satisfied in step 45.

When the condition for CH to be set to FLG=1 is satisfied, the motor 14 is activated so that the opening degree of the second throttle valve 13 is decreased in step 46.
and the second throttle valve opening T before performing this drive.
TH until the second throttle valve opening degree T)l is no longer smaller than HOLD, that is, by executing step 46.
=TI (in step 4, the control is performed until the second throttle valve 13 reaches the fully closed limit opening) until it is maintained at oto.
6 and repeat the loop.

In step 48, the timer value of the hold timer that measures the time during which the second throttle valve is at its fully closed limit opening is checked, and when this reaches the set time A, the process goes to step 49, and the second throttle valve at this time is The valve opening degree TH is stored in the RAM as the fully closed opening degree T)ICLO6I+.

Then, in step 50, it is checked whether this fully closed opening degree THctosE is less than the set value B stored in the ROM 19. If it is less than the set value B, there is no abnormality in the second throttle valve control system, so leave it as is, but if TI (CLO54≧B) Since there is an abnormality in the second throttle valve control system, the lamp 21 is turned on in step 51 to warn of the abnormality, and then the control is changed to step 5.
Proceed to step 2.

In steps 52 and 53, the motor 14 is driven to increase the opening degree of the second throttle valve 13, and this driving is continued until the second throttle valve opening degree TH matches the full open value THop□, and the second throttle valve 13 is increased in opening degree. 13 to fully open so that normal driving will not be affected after the engine starts, and the 3rd
With reference to the figure, the predetermined traction control described above is brought into a state in which it can be executed. Thereafter, in step 54, the check flag CHKFLG is reset, and the reset routine is completed in preparation for abnormality determination at the next engine start.

Since the above-described abnormality determination is performed each time the engine is started, it is possible to solve the conventional problem in which the abnormality is known only when a drive slip occurs and it becomes impossible to prevent the abnormality. In addition, the fully closed position of the second throttle valve can be memorized again each time the engine is started (see step 49), and the flow shown in Figure 3 when the vehicle is running is then repeated, and the second throttle valve is closed during traction control. When the process of closing the valve to the fully closed position occurs, the opening degree of the second throttle valve is determined based on the accurate position that has been newly stored in memory, so the performance of the traction control may deteriorate due to aging of the sensor. Furthermore, it is possible to prevent the memory of the second throttle valve fully closed position from being erased due to removal of the battery and the like, thereby preventing traction control from becoming impossible.

(Effects of the Invention) As described above, the device of the present invention closes the second throttle valve to its limit once when starting the engine, which requires no traction control and requires the minimum engine output, and monitors its fully closed limit opening. Since the configuration is configured to determine an abnormality in the second throttle valve control system, this abnormality can be detected at the front each time the engine is started, and the fully closed position of the second throttle valve can be determined by monitoring the above-mentioned fully closed side limit opening. By always storing accurate information in memory, you can prevent traction control performance from deteriorating.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of the abnormality detection device of the present invention, FIG. 2 is a system diagram of a traction control device showing an embodiment of the present invention, FIG. 3 is a flowchart showing a control program for traction control in the same example, and FIG. The figure is a flowchart showing a control program for abnormality determination in the same example. IL, IR...front wheels 2L, 2R...rear wheels 3...engine 4...ignition switch 5...accelerator pedal 6...first throttle valve 7...automatic transmission 9...・Differential gear 13...Second throttle valve 14...Motor 15...Traction controller 21...Abnormality warning lamps 22, 23.24...Rotation sensor 25...Low reencoder 26... Brake switch 27...inhibitor switch Fig. 1

Claims (1)

[Scope of Claims] 1. Wheels can be driven by an engine whose output is determined by a throttle valve linked to an accelerator pedal, and when the wheels slip, a second throttle valve is connected in series with the throttle valve. In a vehicle equipped with a traction control device that prevents drive slip by reducing the opening of the engine, the engine start detection means detects the start of the engine, and a second throttle valve that temporarily closes the second throttle valve to a limit when the engine starts. a fully closed side limit opening detection means for detecting the fully closed side limit opening of the second throttle valve; and a second throttle valve control system when the fully closed side limit opening is equal to or greater than a set value. An abnormality detection device for a traction control device, comprising abnormality determining means for determining an abnormality in a traction control device.