JPH0745838B2 - Abnormality detection device for traction control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a different condition determining device of a traction control device for preventing drive slip (wheel spin) of a wheel.

(Prior Art) A vehicle can travel by driving wheels with an engine whose output is determined by a throttle valve that interlocks with an accelerator pedal. Conventionally, as a traction control device for preventing the drive slip of the wheels during traveling, there is a conventional Japanese patent publication.
As described in JP 61-60331 A and JP 61-129432 A, a second throttle valve is provided in series with the throttle valve, and when a drive slip occurs, the opening of the second throttle valve is reduced to reduce the engine output. There is a device in which the drive slip is prevented by the reduction.

(Problems to be Solved by the Invention) In such a traction control device, the second throttle valve is kept in the fully opened state except when the wheel is in the drive slip state, and the drive slip is extremely rarely generated. It may not be possible to close it to the position that prevents drive slip even if it is not sticked. Conventionally, there is no device for detecting such an abnormality, and it is the actual situation that when the drive slip of the wheel occurs, the abnormality cannot be prevented until the abnormality is detected. In addition, 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 the second value is used when a drive slip occurs.
The throttle valve is closed according to the slip state, and when the slip state is large, the second throttle valve is driven until the throttle opening sensor outputs the value at the fully closed position. However, if the sensor changes with time, the accurate fully closed position cannot be determined, the second throttle valve cannot be closed to the original fully closed position, and the traction control performance deteriorates. Further, even if the memory is backed up at the fully closed position, the traction control itself may be disabled due to the memory being erased by removing the battery or the like.

According to the present invention, the second throttle valve is once closed to the limit each time the engine is started, and the fully closed side limit opening degree is monitored to detect an abnormality or to confirm the fully closed position of the second throttle valve. The purpose is to solve the problem of.

(Means for Solving the Problem) For this purpose, the abnormality detection device of the present invention runs by driving wheels with an engine whose output is determined by a throttle valve interlocked with an accelerator pedal, as the concept is shown in FIG. A vehicle equipped with a traction control device capable of reducing the opening of a second throttle valve that is in series with the throttle valve when driving slip of the wheel to prevent driving slip, and detects engine start detection. Means, a second throttle valve closing means for closing the second throttle valve when the engine is started in response to a signal from the means, and the opening degree reduction of the second throttle valve by the means over a set time. Second throttle valve closing operation limit determining means for determining the closing operation limit of the second throttle valve when stopped, and the second throttle closing means by the means. Second throttle valve fully closed side limit opening detection means for detecting the fully closed side opening degree of the second throttle valve when the closing operation limit of the throttle valve is determined; and the second throttle detected by this means An abnormality determining means for determining that the second throttle valve control system is abnormal when the fully closed limit opening degree of the valve is equal to or larger than a set value is provided.

(Operation) After the engine is started, the output of the engine is determined by the throttle valve that interlocks with the accelerator pedal, and the wheels can be driven by this output to drive the vehicle. When the wheel slips while driving, the traction control device reduces the opening of the second throttle valve and makes the engine output smaller than the accelerator pedal depression amount corresponding value to prevent the wheel slip.

The engine start detection means detects this when the engine is started. The engine at the time of starting does not require traction control and the engine output may be the minimum, so that the second throttle valve may be fully closed.
The engine starting second throttle valve closing means closes the second throttle valve in response to a signal from the engine starting detecting means. Then, the second throttle valve closing operation limit determining means determines the closing operation of the second throttle valve when the decrease of the opening is stopped for a set time during the closing operation of the second throttle valve by the second throttle valve closing means. It is determined that the limit, the second throttle valve fully closed side limit opening detection means,
The fully closed side limit opening degree of the second throttle valve is detected when the closing operation limit of the second throttle valve is determined.
Here, the abnormality determining means determines that the second throttle valve control system is abnormal when the detected fully closed limit opening degree of the second throttle valve is equal to or larger than the set value. Therefore, the abnormality that the second throttle valve is stuck in the fully open position or cannot be closed to the drive slip prevention position can be checked every time the engine is started, and when this abnormal drive slip occurs, it cannot be prevented. It is possible to solve the conventional problems that can only be known by going to. Further, the fully closed position of the second throttle valve can be re-stored each time the engine is started, and when it becomes necessary to drive the second throttle valve to the fully closed position by the traction control thereafter, it is newly stored. The second motor throttle valve is driven until the throttle opening sensor outputs the output value corresponding to the fully closed position. As a result, the performance of the traction control deteriorates due to aging of the sensor,
Further, the memory at the fully closed position of the second throttle valve is erased by removing the battery or the like, and the traction control is not deteriorated or disabled.

(Example) Hereinafter, the Example of this invention is described in detail based on drawing.

FIG. 2 is a system diagram of a traction control device showing an embodiment of the device of the present invention. 1L and 1R are left and right front wheels, and 2L and 2R.
Indicates the left and right rear wheels, and 3 indicates the engine, respectively. The engine 3 is started by the ignition switch 4, and the output is determined according to the opening degree of the first throttle valve 6 which is interlocked with the accelerator pedal 5 depressed by the driver. The output of the engine 3 is used for driving the left and right rear wheels 2L, 2R via a propeller shaft 8 and a differential gear 9 after shifting by the automatic transmission 7, and the vehicle can be driven. When braking a vehicle,
By depressing the brake pedal 10, the brake units 11L, 11R, 12L, 12R of the respective wheels are operated.

A second throttle valve 13 is provided in series with the first throttle valve 6 for traction control and can be independently rotated by a reversible DC motor 14. The direction and amount of rotation of the motor 14 is controlled by the traction controller 15, which is a F / V converter 16, A / D converter 17, central processing unit (CPU) 18 with built-in random access memory (RAM), read-only A microcomputer including a memory (ROM) 19 and a motor drive circuit 20. The traction controller 15 is also used to turn on the abnormality warning lamp 21 when an abnormality described later is detected.

The traction controller 15 has its F / V converter 1
Rotation sensors 22 and 2 that detect the rotation speeds V _FL and V _FR of the left and right front wheels
Signal from 3 and rotation speed of propeller shaft 8 (rear 2
Average rotation speed of the wheel) V _R Input the signal from the rotation sensor 24 to detect. The F / V converter 16 receives these input information (frequency signal). Is converted into a voltage and input to the A / D converter 17. The A / D converter 17 further includes a second throttle valve 1
The signal from the rotary encoder (throttle opening sensor) 25 that detects the opening TH of 3 is input. A / D converter 1
7 converts the input analog signal into a digital signal and supplies it to the CPU 18. The CPU 18 further includes a signal IG when the engine is started by the ignition switch 4, a signal from the brake switch 26 that is turned on when the brake pedal 5 is stepped on, and a signal from the inhibitor switch 27 that detects the selected range of the automatic transmission 7. Enter.

The CPU 18 executes the control programs shown in FIGS. 3 and 4 stored in the ROM 19 based on the input information, drives the motor 14 through the motor drive circuit 20 to perform traction control, and detects an abnormality in the traction control device. Is detected and the lamp 21 is turned on at the time of abnormality.

First, the traction control of FIG. 3 will be described.
A control program of Figure 3 is intended to interrupt processing at predetermined time intervals [Delta] T, the wheel speed V _FL at step 31, V _FR, reads the V _R, the average wheel speeds of the two front wheels in step 32 Calculates a driving rear wheel 2L in step 33, the driving slip ratio S of the 2R calculated by _{S = (V R -V F)} / V F. In the next step 34, it is checked whether or not the drive slip ratio S is equal to or more than the set value S _{0 and} the wheel spin occurs.

If wheel spin is occurring, the motor 14 is operated to reduce the opening of the second throttle valve 13 in step 35 as follows.
To drive. That is, first, the opening of the second throttle valve 13 required to prevent this is calculated from the magnitude of the drive slip ratio S, and the rotational direction of the motor 14 is calculated from the deviation between this and the current second throttle valve opening TH. By determining and outputting the rotation amount, the opening of the second throttle valve 13 is reduced to the calculated value, and the drive slip is prevented. Although omitted in FIG. 3, if necessary, the second throttle valve 13 is driven to the fully closed position and the motor 14 is stopped.

If no wheel spin occurs, the opening degree of the second throttle valve 13 is increased by a constant opening degree in step 36, and as a result, the second throttle valve 13 is moved at a speed represented by the ratio of the interruption interval ΔT to the constant opening degree. To increase the opening toward fully open. Also at this time, the motor 14 is stopped when the throttle valve 13 is fully opened.

FIG. 4 shows a reset routine for abnormality detection which is processed each time the engine start signal IG is input. First, in step 41, the RAM data in the CPU 18 is cleared. Next, in steps 42 and 43, it is checked whether the selected range of the automatic transmission 7 detected by the inhibitor switch 27 is the parking (P) range while the brake switch 26 is ON. Since the traction control is not performed when the engine is starting, the brake is being operated, and the P range is being selected, and the engine output is at a minimum, the second throttle valve 13 is fully closed for abnormality determination of its operating system. Since there is no problem even if the operation test is performed, the check flag CHKFLG is set to 1 in step 44 to indicate this. When the conditions in steps 42 and 43 are not satisfied, the control is returned to step 42 and the above loop is repeated until the conditions are satisfied in step 45.

When the condition of CHKFLG = 1 is satisfied, the motor 14 is driven so as to decrease the opening degree of the second throttle valve 13 in step 46, and the second throttle valve opening TH _OLD before this driving
The control proceeds to step 46 until the throttle valve opening TH does not become small, that is, until TH = TH _OLD is maintained even by executing step 46, in other words, until the second throttle valve 13 reaches the fully closed side limit opening. Return and repeat the loop.

At step 48, the timer value of the hold timer that measures the time when the second throttle valve is at the fully closed side limit opening degree is checked, and when it reaches the set time A, step 49
At this time, the second throttle valve opening TH is set to the fully closed opening TH
Memory in RAM as _CLOSE . Then, in step 50, it is checked whether or not this fully closed opening TH _CLOSE is less than the set value B stored in the ROM 19, and if it is less than that, there is no abnormality in the second throttle valve control system, but if TH _CLOSE ≧ 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 step
Continue to 52.

Therefore, step 46 corresponds to the second throttle valve closing means, steps 47 and 48 correspond to the second throttle valve closing operation limit determining means, and step 49 corresponds to the second throttle valve fully closing side limit opening detecting means. However, step 50 corresponds to abnormality determining means.

In steps 52 and 53, the motor 14 is driven so that the opening of the second throttle valve 13 increases, and this drive is continued until the second throttle valve opening TH coincides with the fully open value TH _OPEN , and the second throttle valve 13 13 is fully opened so that the normal running after the engine is started is not hindered, and the predetermined traction control described above with reference to FIG. 3 is made executable. After that, in step 54, the check flag CHKFLG is reset, and the reset routine is ended in preparation for the abnormality determination at the next engine start.

Since the above abnormality determination is performed each time the engine is started, it is possible to solve the conventional problem that can be known only when the abnormality cannot be prevented when a drive slip occurs. Also, the fully closed position of the second throttle valve can be re-memorized each time the engine is started (see step 49), and then the flow of FIG. 3 when the vehicle is running is repeated and the second throttle valve is opened during traction control. When the process of closing to the fully closed position occurs, the opening of the second throttle valve is determined based on the newly re-stored accurate position, so that the performance of traction control deteriorates due to the secular change of the sensor. In addition, it is possible to prevent the traction control from being disabled by erasing the memory at the second throttle valve fully closed position due to removal of the battery or the like.

(Effects of the Invention) Thus, in the device of the present invention, as described above, the second throttle valve is operated to be closed at the time of engine starting where traction control is not required and the engine output is minimum, and during this closing operation, the second throttle valve is operated.
It is determined that the closing operation limit of the second throttle valve is reached when the decrease in the opening degree of the throttle valve is stopped for a set time, and the fully closed limit opening degree of the second throttle valve at the time of the determination is detected. When the value is equal to or more than the set value, the second throttle valve control system is determined to be abnormal, so that this abnormality can be known in advance every time the engine is started. It is possible to prevent the performance deterioration of the traction control by always accurately storing the fully closed position of the second throttle valve by the monitor.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of an 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 of traction control in the same example, and FIG. The figure is a flow chart showing a control program for abnormality determination in the same example. 1L, 1R …… front wheel 2L, 2R …… rear wheel 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 alarm lamp 22,23,24 …… Rotation sensor 25 …… Rotary encoder 26 …… Brake switch 27 …… Inhibitor switch

Claims (2)

[Claims] 1. An engine, the output of which is determined by a throttle valve interlocked with an accelerator pedal, is capable of driving a wheel for traveling, and a second throttle valve in series with the throttle valve is opened when the wheel slips. A vehicle equipped with a traction control device for reducing the drive slip and closing the second throttle valve when the engine is started in response to a signal from the engine start detecting means for detecting the start of the engine. Second throttle valve closing means for operating, and second throttle valve closing operation limit determination for determining the closing operation limit of the second throttle valve when the reduction of the opening degree of the second throttle valve by the means is stopped for a set time Means and a limit opening side of the second throttle valve when the closing operation limit of the second throttle valve is determined by the means. Second throttle valve fully closed side limit opening degree detecting means for detecting the degree, and when the fully closed side limit opening degree of the second throttle valve detected by this means is equal to or more than a set value, the second throttle valve control system An abnormality detection device for a traction control device, comprising an abnormality determination means for determining that the abnormality is present. 2. The second throttle valve closing means ends the closing operation of the second throttle valve after detecting the fully closed side limit opening degree by the second throttle valve fully closed side limit opening degree detecting means. 2. The abnormality detection device for a traction control device according to claim 1, wherein the throttle valve is fully opened.