JPH08332941A - Anti-lock control device - Google Patents

Abstract

PURPOSE: To prevent the reduction of deceleration of a vehicle with the occurrence of unnecessary pressure reduction of brake liquid pressure by determining an estimated car body speed based on each wheel speed of other wheels than a wheel having abnormality by an estimated car body speed calculation means when the abnormal speed of the wheel is detected. CONSTITUTION: A wheel speed and wheel deceleration computing part 3 in an ABS control device 1 calculates the speed and deceleration of each wheel based on signals from wheel speed sensors 2a-2d, and the result of calculation is inputted to an abnormality detection part 4, and when the wheel speed of an abnormal value is detected, it is determined as abnormality of the wheel speed sensor, so abnormal wheel speed is detected. At an estimated car body speed computing part 5, an estimated car body speed is calculated based on each wheel speed except for the abnormal wheel speed, and at a wheel condition detection part, wheel lock and skid conditions of wheels are detected based on the wheel speed, wheel deceleration, and estimated car body speed, and a liquid pressure control device 9 is controlled based on the result of detection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle anti-lock control device, and more particularly to calculating an estimated vehicle body speed so that unnecessary ABS control is not performed when noise or the like is superimposed on a wheel speed sensor. The present invention relates to an antilock control device.

[0002]

2. Description of the Related Art A conventional antilock control device calculates a wheel speed and a wheel deceleration of each wheel from each signal indicating the wheel speed from a wheel speed sensor provided for each wheel. Further, an estimated vehicle body speed is calculated from the wheel speed of each wheel, the wheel state such as a wheel lock is detected from the wheel speed, each wheel deceleration, and the estimated vehicle body speed, and each wheel state is detected according to the state of the wheel. By adjusting the brake fluid pressure of the wheels, it is intended to ensure the steerability and running stability of the vehicle and shorten the braking distance. However, if noise is superimposed on the signal from the wheel speed sensor for some reason, the wheel speed cannot be calculated accurately, and the accuracy of ABS control deteriorates.

In order to solve the above problem, Japanese Patent Publication No. 5-53674 discloses that when an abnormal wheel speed is detected, the wheel speed and the wheel deceleration of the wheel in which the abnormal wheel speed is detected are detected in the control cycle. There is disclosed a vehicle control device that attempts to prevent unnecessary reduction of brake fluid pressure by replacing the speed with a value obtained in the previous control cycle.

[0004]

FIG. 15 shows wheel speeds and estimated vehicle body speeds when the vehicle control device disclosed in Japanese Patent Publication No. 5-53674 is used, and when the device is not used. 3 is a diagram showing a wheel speed in FIG. 4 and an estimated vehicle body speed when noise is not superimposed on the wheel speed.

In FIG. 15, the solid line is the Japanese Patent Publication No. 5-536.
When the vehicle control device disclosed in Japanese Patent Laid-Open No. 74 is not used, the wheel speed on which noise is superimposed (indicated as an actual wheel speed in the figure) is shown, and a chain double-dashed line indicates a case where the vehicle control device is used. The wheel speed when noise continues to be superimposed is shown. Also, the one-dot chain line shows the estimated vehicle body speed (in the figure, referred to as the actual estimated vehicle body speed) when noise is not superimposed on the wheel speed, and the broken line uses the vehicle control device disclosed in Japanese Patent Publication No. 5-53674. The estimated vehicle body speed when noise continues to be superimposed on the wheel speed in the case of

As shown in FIG. 15, in the vehicle control device disclosed in the above publication, when noise continues to be superimposed on the wheel speed sensor, the estimated vehicle body speed is in the case where noise is not superimposed on the wheel speed. Since the vehicle speed will eventually become higher than the estimated actual vehicle speed, unnecessary brake fluid pressure will be reduced, resulting in a decrease in vehicle deceleration.

The present invention prevents deterioration of the accuracy of ABS control when noise is superimposed on the signal from the wheel speed sensor, and unnecessary reduction of the brake fluid pressure occurs even when the noise continues to be superimposed. An object of the present invention is to obtain an anti-lock control device that can prevent a decrease in deceleration of a vehicle due to.

[0008]

SUMMARY OF THE INVENTION Therefore, the present invention provides
At least one wheel speed detecting means for detecting the speed of each wheel, wheel speed calculating means for calculating the wheel speed of the wheel from a signal from the wheel speed detecting means, and for each wheel calculated by the wheel speed calculating means In an anti-lock control device having an estimated vehicle body speed calculating means for calculating an estimated vehicle body speed from wheel speeds, when an abnormality in the wheel speed of each wheel is detected and an abnormality in the wheel speed is detected, the estimated vehicle body speed is calculated. There is provided an antilock control device characterized in that the means is provided with an abnormality detecting means for calculating the estimated vehicle body speed from each wheel speed of wheels other than the wheel speed of the wheel.

In the invention according to claim 2 of the present application, the abnormality detecting means according to claim 1 calculates the wheel speed calculated in the current control cycle for the same wheel in the previous control cycle. When the wheel speed becomes greater than the predetermined wheel speed by a predetermined value or more, the current wheel speed of the wheel is determined to be abnormal, and the estimated vehicle body speed calculation means excludes the wheel speed of the wheel until a predetermined process is performed. The estimated vehicle body speed in this control cycle is calculated from the wheel speeds of the wheels.

In the invention according to claim 3 of the present application, the abnormality detecting means according to claim 1 calculates the wheel speed calculated in the present control cycle in the previous control cycle for the same wheel. After detecting that the wheel speed is greater than the predetermined wheel speed by a predetermined value or more, the estimated vehicle speed calculation means is operated for a predetermined time from each wheel speed of other wheels except the wheel speed of the wheel in the present control cycle. It is characterized in that the estimated vehicle speed is calculated.

In the invention according to claim 4 of the present application, the abnormality detecting means according to any one of claims 1 to 3 is used when the estimated vehicle body speed is calculated by the estimated vehicle body speed calculating means. The time to exclude the wheel speed determined to be abnormal is set according to the deviation between the wheel speed calculated in the current control cycle and the wheel speed calculated in the previous control cycle.

In the invention according to claim 5 of the present application, the abnormality detecting means according to any one of claims 1 to 4 detects the abnormality in the wheel speed of the same wheel when the abnormality is detected a predetermined number of times. It is characterized in that it is determined that the speed detecting means is abnormal, the ABS control of all the wheels is prohibited, and the prohibition of the ABS control is not released until a predetermined restoration process is performed.

In the invention according to claim 6 of the present application, the abnormality detecting means according to claim 1 calculates the wheel speed calculated in the present control cycle in the previous control cycle for the same wheel. After detecting that the wheel speed is greater than the predetermined wheel speed by a predetermined value or more, the estimated vehicle body speed is maintained until the wheel speed becomes a value within a predetermined range with respect to the estimated vehicle body speed calculated by the estimated vehicle body speed calculation means. It is characterized in that the speed calculating means calculates the estimated vehicle body speed in the current control cycle from the wheel speeds of the wheels other than the wheel speed of the wheel.

In the invention according to claim 7 of the present application, the abnormality detecting means according to claim 6 detects the abnormality in the wheel speed of the same wheel for a predetermined time or more. It is characterized in that it is determined to be abnormal and the ABS control of all the wheels is prohibited, and the prohibition of the ABS control is not released until a predetermined restoration process is performed.

[0015]

In the device according to the first aspect of the invention, the abnormality detecting section detects an abnormality in the wheel speed of each wheel, and when the abnormality in the wheel speed is detected, the estimated vehicle body speed is calculated. In order to cause the means to calculate the estimated vehicle body speed from each wheel speed of other wheels excluding the wheel speed of the wheel,
Even if noise continues to be superimposed on the wheel speed sensor, it is possible to prevent unnecessary reduction of brake fluid pressure due to the calculated estimated vehicle body speed becoming larger than the actual value when noise is not superimposed. , In the anti-lock control device,
Greatly improve safety and reliability.

In the apparatus according to claim 2 of the claims, the abnormality detecting means according to claim 1 calculates the wheel speed calculated in this control cycle in the previous control cycle for the same wheel. When the wheel speed becomes greater than the predetermined wheel speed by a predetermined value or more, the current wheel speed of the wheel is determined to be abnormal, and the estimated vehicle body speed calculation means excludes the wheel speed of the wheel until a predetermined process is performed. In order to calculate the estimated vehicle body speed in this control cycle from each wheel speed of each wheel, even if noise continues to be superimposed on the wheel speed sensor, the calculated estimated vehicle body speed is based on the actual value when noise is not superimposed. It is possible to prevent the unnecessary reduction of the brake fluid pressure, and it is possible to greatly improve the safety and reliability of the antilock control device.

In the apparatus according to claim 3 of the claims, the abnormality detecting means according to claim 1 calculates the wheel speed calculated in the present control cycle in the previous control cycle for the same wheel. After detecting that the wheel speed is greater than the predetermined wheel speed by a predetermined value or more, the estimated vehicle speed calculation means is operated for a predetermined time from each wheel speed of other wheels except the wheel speed of the wheel in the present control cycle. In order to calculate the estimated vehicle body speed, even if noise is superimposed on the wheel speed sensor multiple times, the calculated estimated vehicle body speed will be larger than the actual value when noise is not superimposed, and unnecessary brake fluid pressure It is possible to prevent decompression.
Furthermore, when noise goes away from the wheel speed sensor when the vehicle is moving away from the noise source while traveling, normal processing can be promptly returned to the safety of the antilock control device. And the reliability can be greatly improved.

In the apparatus according to claim 4 of the claims, when the abnormality detecting means according to any one of claims 1 to 3 calculates the estimated vehicle body speed with respect to the estimated vehicle body speed calculating means. Since the time excluding the wheel speed determined to be abnormal is set according to the deviation between the wheel speed calculated in this control cycle and the wheel speed calculated in the previous control cycle, noise is generated in the wheel speed sensor. It is possible to prevent the calculated estimated vehicle body speed from becoming larger than the actual value when the noise is not superimposed even if it is superimposed a plurality of times, and causing unnecessary reduction of the brake fluid pressure. Furthermore, when the vehicle is moving away from the noise source while traveling, when the noise no longer overlaps with the wheel speed sensor,
The normal processing can be promptly returned, and the safety and reliability of the antilock control device can be greatly improved.

In the apparatus according to claim 5 of the present invention, when the abnormality detecting means according to any one of claims 1 to 4 detects an abnormality in the wheel speed of the same wheel a predetermined number of times, the wheel is wheeled. Since it is determined that the speed detection means is abnormal and the ABS control of all wheels is prohibited and the prohibition of the ABS control is not released until a predetermined restoration process is performed, not only external noise but also the wheel speed sensor and the It is possible to prevent unnecessary decompression of the brake fluid pressure from occurring due to the calculated estimated vehicle body speed becoming higher than the normal value due to the failure of the peripheral part of the sensor, and the safety of the anti-lock control device. The reliability can be greatly improved.

In the apparatus according to claim 6 of the claims, the abnormality detecting means according to claim 1 calculates the wheel speed calculated in the current control cycle in the previous control cycle for the same wheel. After detecting that the wheel speed is greater than the predetermined wheel speed by a predetermined value or more, the estimated vehicle body speed is maintained until the wheel speed becomes a value within a predetermined range with respect to the estimated vehicle body speed calculated by the estimated vehicle body speed calculation means. When the noise is no longer superimposed on the wheel speed sensor, the speed calculation means calculates the estimated vehicle speed in each control cycle from the wheel speeds of the other wheels excluding the wheel speed of the wheel. Even if noise continues to be superimposed on the wheel speed sensor, the calculated estimated vehicle body speed becomes larger than the actual value when noise is not superimposed, and Such reduced pressure of the brake fluid pressure can be prevented from occurring, the anti-lock control device, it is possible to great improvement in safety and reliability.

In the apparatus according to claim 7 of the claims, when the abnormality detecting means according to claim 6 detects an abnormality in the wheel speed of the same wheel for a predetermined time or more,
When it is determined that the wheel speed detecting means is abnormal and the ABS control of all the wheels is prohibited and the prohibition of the ABS control is not released until a predetermined restoration process is performed, noise is no longer superimposed on the wheel speed sensor. , It is possible to return to normal processing promptly, and even if noise continues to be superimposed on the wheel speed sensor, the calculated estimated vehicle speed becomes larger than the actual value when noise is not superimposed, which is unnecessary. It is possible to prevent the brake fluid pressure from being reduced, and it is possible to greatly improve the safety and reliability of the antilock control device.

[0022]

The present invention will now be described in detail with reference to the embodiments shown in the drawings. FIG. 1 is a schematic block diagram showing an embodiment of an antilock control device (hereinafter referred to as an ABS control device) of the present invention.

In FIG. 1, the ABS control device 1 includes a wheel speed sensor 2a, 2b, 2c, 2d provided on each wheel.
, Wheel speed and wheel deceleration calculation unit 3, and abnormality detection unit 4
And an estimated vehicle speed calculation unit 5, a wheel state detection unit 6, a hydraulic pressure control device drive unit 7, and a control prohibition unit 8. The wheel speed and wheel deceleration calculation unit 3 calculates the speed and deceleration of each wheel from the signals from the wheel speed sensors 2a, 2b, 2c, 2d, and the abnormality detection unit 4 determines the wheel speed and the wheel speed. An abnormal wheel speed is detected from the wheel speed calculated by the deceleration calculation unit 3.

The estimated vehicle body speed calculator 5 calculates the estimated vehicle body speed from the wheel speed calculated by the wheel speed and wheel deceleration calculator 3 and input through the abnormality detector 4, and the wheel state detector 6 Detects a wheel lock and skid state from the wheel speed and wheel deceleration calculated by the wheel speed / wheel deceleration calculation unit 3 and the estimated vehicle body speed calculated by the estimated vehicle body speed calculation unit 5. Further, the hydraulic pressure control device drive unit 7 controls the drive of a hydraulic pressure control device 9 that increases / decreases or maintains the brake hydraulic pressure of each wheel, and the control prohibition unit 8 causes the abnormality detection unit 4 to detect the abnormality. When it is detected a predetermined number of times or more, the system down is performed to prohibit the ABS control for the hydraulic pressure control device drive unit 7. The system down is
It will not be canceled unless a predetermined process is performed.

The above wheel speed sensors 2a, 2b, 2c, 2
d is connected to the wheel speed and wheel deceleration calculation unit 3, respectively, and the wheel speed and wheel deceleration calculation unit 3 is connected to the abnormality detection unit 4 and the wheel state detection unit 6. The abnormality detection unit 4 is connected to the estimated vehicle body speed calculation unit 5 and the control prohibition unit 8, and the estimated vehicle body speed calculation unit 5 is connected to the wheel state detection unit 6. Further, the wheel state detection unit 6 is connected to the hydraulic pressure control device drive unit 7, the hydraulic pressure control device drive unit 7 is connected to the hydraulic pressure control device 9, and the control prohibition unit 8 is connected to the hydraulic pressure control device drive unit 7. Has been done. The wheel speed sensors 2a to
2d is wheel speed detecting means, wheel speed and wheel deceleration calculating section 3 is wheel speed calculating means, estimated vehicle speed calculating section 5 is estimated vehicle speed calculating means, and abnormality detecting section 4 and control prohibiting section 8 are detecting abnormality. Make a means.

The ABS control operation when the wheel speeds of the respective wheels are not abnormal in the above structure will be described. The wheel speed and wheel deceleration calculation unit 3 waveform-processes each AC signal input from each of the wheel speed sensors 2a to 2d into a rectangular wave, and calculates the time between edges where the voltage of these rectangular waves changes. After each measurement, the speed of each wheel is calculated based on these, and the speed of each wheel is output to the abnormality detection unit 4 and the wheel state detection unit 6.

The abnormality detecting section 4 includes wheel speed sensors 2a to 2d.
It is checked whether the wheel speed and the wheel speed calculated by the wheel deceleration calculation unit 3 show an abnormal value due to the superposition of noise or the like on each input signal. If not, wheel speed and wheel deceleration calculation unit 3
The estimated vehicle body speed calculation unit 5 is caused to calculate the estimated vehicle body speed from each wheel speed input from. The estimated vehicle body speed calculation unit 5 outputs the calculated estimated vehicle body speed to the wheel state detection unit 6. Since the method of calculating the estimated vehicle body speed is well known, its explanation is omitted here.

Here, when the abnormality detecting unit 4 detects an abnormal wheel speed, it determines that an abnormality has occurred in the wheel speed sensor corresponding to the wheel speed, and the estimated vehicle speed calculating unit 5
On the other hand, the estimated vehicle body speed is calculated from the wheel speeds other than the abnormal wheel speed, and the estimated vehicle body speed calculation unit 5 outputs the calculated estimated vehicle body speed to the wheel state detection unit 6. Further, when the abnormality is detected on the same wheel a predetermined number of times or more, the abnormality detecting unit 4 commands the control prohibiting unit 8 to perform the system down, and the control prohibiting unit 8 controls the hydraulic pressure according to the command. The system drive unit 7 is caused to perform system down.

In the wheel state detecting section 6, for example, the difference between the wheel speed input from the wheel speed / wheel deceleration calculating section 3 and the estimated vehicle body speed input from the estimated vehicle body speed calculating section 5 is a constant value. If it exceeds, it is determined that the wheels are locked, and a pressure reducing signal for reducing the brake pressure of the wheels is output to the hydraulic pressure control device driving unit 7 to output the hydraulic pressure control device driving unit 7.
Causes the hydraulic pressure control device 9 to reduce the brake hydraulic pressure of the corresponding wheel.

If the difference between the wheel speed of the corresponding wheel and the estimated vehicle body speed becomes smaller than a certain value due to the reduction of the brake fluid pressure of the corresponding wheel, the wheel state detecting unit 6 avoids the wheel lock. When it is determined that the brake pressure has been applied to the hydraulic pressure control device drive unit 7, the hydraulic pressure control device drive unit 7 outputs to the hydraulic pressure control device drive unit 7 a pressurization signal for increasing the brake pressure of the corresponding wheel. Re-pressurize fluid pressure.

Next, FIGS. 2 and 3 are flowcharts showing a first operation example in the embodiment of the apparatus of the present invention shown in FIG. 1, and FIG. 2 and FIG. In particular, a first operation example of the abnormality detection unit 4 will be described. In FIG. 2, the abnormality detecting unit 4 first clears the abnormality number counters FC1, FC2, FC3, and FC4, which count the number of times an abnormality is detected for each wheel, to 0 in step S1 as an initial setting, and then in step S2. The abnormality flags F1, F2, F3, and F4, which are flags indicating the abnormality of the wheel speed sensor for which the abnormal wheel speed has been calculated, are reset and cleared. Next, in step S3, the index provided for each wheel is counted, and the index counter i used for determining whether or not the processing has been completed for all four wheels is set to 1, and the process proceeds to step S4. move on.

In step S4, the abnormality detecting section 4 detects the wheel speed sensor of the wheel corresponding to the counter value set in the index counter i, for example, when the counter value 1 indicates the right front wheel, the wheel speed sensor 2a of the right front wheel. Wheel speed SPEED1 in the previous control cycle calculated from the signal from the wheel speed LSSPEED1 of the front right wheel in the previous control cycle
Then, in step S5, the wheel speed of the right front wheel calculated in this control cycle is set to SPEED1, and then in step S6,
Increment the index counter i.

Next, in step S7, the abnormality detecting unit 4 checks whether or not the counter value of the index counter i is 5, and if the counter value of the index counter i is not 5 (NO), returns to step S4. , If the counter value of the index counter i is 5, (YE
S), and proceed to step S8. In the embodiment of the present invention, the subscript i indicates the counter value of the index counter i.

The abnormality detecting section 4 sets the fastest wheel speed VH among the wheel speeds of the respective wheels to 0 as an initial setting in step S8, sets the index counter i to 1 in step S9, and then in step S10. , A value ΔSPEEDi obtained by subtracting the wheel speed LSSPEEDi in the previous control cycle from the wheel speed SPEEDi in the current control cycle is calculated, and it is checked whether or not the ΔSPEEDi is less than the predetermined value a. (YES), the process proceeds to step S11. If the value is equal to or more than the predetermined value a in step S10 (NO), the abnormality flag Fi indicating that the wheel speed SPEEDi is abnormal is set in step S12, and then in step S13, the counter value of the abnormality number counter FCi is incremented. Then, the process proceeds to step S11. The predetermined value a is a value of the wheel speed that changes during one control cycle that is usually considered, and for example, one control cycle is 8 msec.
In the case of, it is 10 to 15 km / h.

In step S11, the abnormality detecting section 4 checks whether or not the counter value of the abnormality counter FCi is less than the predetermined value α, and if it is more than the predetermined value α (NO),
In step S14, the system down flag (hereinafter referred to as SD flag) FSD is set, and in response to the setting of the SD flag FSD, the control prohibiting unit 8 instructs the hydraulic pressure control device driving unit 7 to perform all operations. This flow is terminated by causing the system down to prohibit the ABS control of the wheels of. Also,
If the counter value is less than the predetermined value α in step S11 (YES), the abnormality detection unit 4 executes step S1 in FIG.
Go to 5.

The abnormality detector 4 checks in step S15 of FIG. 3 whether or not the abnormality flag Fi is reset and cleared. If the abnormality flag Fi is cleared (YES), in step S16, It is checked whether or not the fastest wheel speed VH at the present time is less than the current wheel speed SPEEDi, and the fastest wheel speed VH at the present time.
Is less than the current wheel speed SPEEDi (YES), the process proceeds to step S17, where the wheel speed SPEE
Let Di be the fastest wheel speed VH and proceed to step S18. If the abnormality flag Fi is not cleared in step S15 (NO), or the fastest wheel speed VH at the present time is the current wheel speed SPEEDi in step S16.
When it is above (NO), the process proceeds to step S18.

The abnormality detecting section 4 operates in step S18 of FIG.
Then, the index counter i is incremented, and in step S19, it is checked whether or not the counter value of the index counter i is 5, and if the counter value of the index counter i is not 5 (NO), the process returns to step S10 of FIG. If the counter value of the index counter i is 5 (YES), the process proceeds to step S20.

In step S20, the estimated vehicle speed calculator 5
Is the fastest wheel speed VH set by the abnormality detection unit 4.
The estimated vehicle body speed is calculated based on, and the estimated vehicle body speed is output to the wheel state detection unit 6. Next, in step S21, the wheel state detection unit 6 sets the index counter i to 1 in step S21, and in step S22, reduces the brake fluid pressure to the wheel corresponding to the counter value of the index counter i. Judge whether the judgment is established,
If the pressure reduction determination is satisfied (YES), the process proceeds to step S23.

In step S23, the wheel state detecting section 6 instructs the hydraulic pressure control device driving section 7 to perform an index counter i.
The brake fluid pressure reduction speed at the wheel corresponding to the counter value of is set, and the process proceeds to step S24. If it is determined in step S22 that the pressure reduction determination is not established (NO), the process proceeds to step S25 and step S25.
In 25, the wheel state detection unit 6 sets the brake fluid pressure pressurization speed for the wheel corresponding to the counter value of the index counter i to the hydraulic pressure control device drive unit 7, and proceeds to step S24.

Next, the wheel condition detector 6 determines in step S2.
In step 4, the counter value of the index counter i is incremented, the process proceeds to step S26, and step S26
Then, it is checked whether or not the counter value of the index counter i is 5, and if the counter value is 5 (YES), the process proceeds to step S27, and if the counter value is not 5 (N
O), that is, if the counter value is less than 5, step S
Return to 22. In step S27, the hydraulic pressure controller drive unit 7
Causes the hydraulic pressure control device 9 to increase / decrease or maintain the brake hydraulic pressure of each wheel in accordance with the set pressure increasing / decreasing speed, and then returns to step S3 in FIG.

FIG. 4 shows the first operation example of this embodiment.
FIG. 5 is a diagram showing the relationship between the wheel speed SPEEDi, the estimated vehicle body speed, and the abnormality flag Fi, and FIG. 5 shows the wheel speed SPEEDi, the estimated vehicle body speed, the counter value of the abnormality number counter FCi in the first operation example of the present embodiment. It is a figure showing the relation of SD flag FSD. In the first operation example of the present embodiment, as shown in FIG. 4, when noise is superimposed on the wheel speed sensor and the wheel speed calculated from the signal of the wheel speed sensor is, for example, one control cycle is 8 msec, one control cycle is used. 10 to 15 km / h
If a sudden rise that cannot be considered normally is shown, such as the above rise, the abnormality is detected and an abnormality flag is set to indicate the wheel speed abnormality.

Further, the wheel speed calculated from the wheel speed sensor of the wheel indicated by the abnormality flag is excluded from the calculation of the estimated vehicle speed, and the estimated vehicle speed is calculated from the calculated wheel speeds of the remaining wheels. Even if noise continues to be superimposed on the wheel speed sensor, the estimated estimated vehicle speed will be larger than the actual value when noise is not superimposed, and unnecessary brake fluid pressure reduction will occur. Can be prevented.

Further, an abnormality occurs in the rotor of the wheel speed sensor or in the peripheral portion of the sensor, and the wheel speed calculated from the signal of the wheel speed sensor suddenly increases in one control cycle, which is not normally considered. In such cases, the condition often occurs at regular intervals.

Therefore, as shown in FIG. 5, when the wheel speed calculated from the signal of the wheel speed sensor in the same wheel shows a sudden increase which cannot be considered normally, the abnormality is detected and the abnormality is detected. When the detected number of times reaches a predetermined number, for example, 50 to 60 times, the SD flag is set, the system down for prohibiting the ABS control of all wheels is performed, and the system down is not released unless a predetermined process is performed. From this, not only external noise,
It is possible to prevent the calculated estimated vehicle body speed from becoming higher than the normal value and causing unnecessary reduction of the brake fluid pressure due to the failure of the wheel speed sensor and the peripheral portion of the sensor. As described above, in the ABS control device, it is possible to greatly improve safety and reliability.

Next, in the first operation example, when the wheel speed calculated from the signal of the wheel speed sensor detects a sudden increase which is not normally considered in one control cycle, an abnormality flag is set, and thereafter, Even when noise is no longer superimposed on the wheel speed sensor, the abnormality flag was still set, but the above abnormality flag is set only while noise is superimposed on the wheel speed sensor. The wheel speed calculated from the wheel speed sensor of the wheel may be excluded from the calculation of the estimated vehicle speed, and the estimated vehicle speed may be calculated from the calculated wheel speeds of the remaining wheels. The example of FIG. 2 is replaced with the flowchart of FIG. 6 and the example of FIG. 3 is replaced with the flowchart of FIG.

FIGS. 6 and 7 are flow charts showing a second operation example in the embodiment of the apparatus of the present invention shown in FIG. 1. By using FIGS. 6 and 7, the apparatus of FIG. A second operation example of the detection unit 4 will be described. In FIGS. 6 and 7, the same flows as those in FIGS. 2 and 3 are denoted by the same reference numerals, and the description thereof will be omitted and only the differences from the flowcharts of FIGS. 2 and 3 will be described.

The difference between FIG. 6 and FIG. 2 is that step S1 of FIG. 2 is replaced with the processing of step S30 and that step S11, step S13 and step S14 of FIG. Step S
After twelve, the processes of steps S31 to S33 are performed. 7 is different from FIG. 3 in the case of NO in step S15 of FIG. 3, step S34, step S35 and step S1.
4 is performed.

In FIG. 6, the abnormality detecting unit 4 first clears the abnormality timers TA1, TA2, TA3 and TA4 for measuring the time during which an abnormality is detected for each wheel to 0 in step S30, Proceeding to S2, the processing from step S2 to step S10 in FIG. Further, in step S10, the abnormality detection unit 4 calculates a value ΔSPEEDi obtained by subtracting the wheel speed LSSPEEDi in the previous control cycle from the wheel speed SPEEDi in the present control cycle, and the ΔSPEEi is calculated.
It is checked whether Di is less than the predetermined value a, and if it is less than the predetermined value a (YES), the process proceeds to step S31. When the value is equal to or larger than the predetermined value a in step S10 (NO), the abnormality flag Fi indicating that the wheel speed SPEEDi is abnormal is set in step S12, and then the process proceeds to step S31.

In step S31, the abnormality detecting unit 4 calculates the wheel speed SPEEDi in the current control cycle by adding the predetermined value b to the estimated vehicle speed VREF calculated by the estimated vehicle speed calculating unit 5 in the previous control cycle. If it exceeds the value obtained by adding the predetermined value b to the estimated vehicle body speed VREF calculated in the previous control cycle (YES), the process proceeds to step S15 of FIG. In step S31, if the estimated vehicle speed VREF calculated in the previous control cycle is equal to or less than the value obtained by adding the predetermined value b (NO), the process proceeds to step S32, and the abnormality detection unit 4 causes the abnormality flag Fi in step S32. Is reset and cleared, and in step S33, the measurement time ΔTAi of the abnormality timer TAi
After 0 is cleared, that is, after the counter value CTAi of the abnormality timer TAi is cleared to 0, the process proceeds to step S15 of FIG. When one control cycle time is e, the relationship of CTAi = ΔTAi / e holds in the counter value CTAi.

In FIG. 7, the abnormality detecting section 4 checks in step S15 whether or not the abnormality flag Fi has been reset and cleared. If the abnormality flag Fi has not been cleared (NO), the procedure goes to step S34. In step S34, the counter value CTAi of the abnormality timer TAi is incremented, and in step S35 the counter value CTAi is incremented.
Check whether the time ΔTAi indicated by is less than a predetermined value β,
If it is less than the predetermined value β (YES), the process proceeds to step S18. In step S35, if the predetermined value β or more (N
O), the process of step S14 is performed, and the present flow ends. In step S19, the index counter i
If the counter value of is not 5 (NO), the process returns to step S10 of FIG. Moreover, after performing the process of step S27, it returns to step S3 of FIG.

FIG. 8 shows the second operation example of this embodiment.
FIG. 9 is a diagram showing the relationship between the wheel speed SPEEDi, the estimated vehicle body speed, and the abnormality flag Fi, and FIG. 9 is the wheel speed SPEEDi, the estimated vehicle body speed, and the abnormality flag F in the second operation example of the present embodiment.
i, measurement time ΔTAi of abnormality timer TAi and SD flag FS
It is a figure showing the relation of D. In the second operation example, as shown in FIG. 8, noise is superimposed on the wheel speed sensor, and the wheel speed calculated from the signal of the wheel speed sensor is equal to the estimated vehicle speed calculated in the previous control cycle by a predetermined value b. Only when the value is equal to or more than the value obtained by adding, the abnormality flag is set to indicate the wheel speed abnormality. The above-mentioned predetermined value b is set to a value that shows a sudden increase that is not normally considered, for example, 10 to 15 km / h when one control cycle is 8 msec.

Further, the abnormality flag is set only while noise is superimposed on the wheel speed sensor, and is calculated from the signal from the wheel speed sensor of the wheel indicated by the abnormality flag only while the abnormality flag is set. The wheel speed is excluded from the calculation of the estimated vehicle speed, and the estimated vehicle speed is calculated from the calculated wheel speeds of the remaining wheels. ,
It is possible to return to normal processing promptly, and even if noise continues to be superimposed on the wheel speed sensor, the calculated estimated vehicle body speed becomes larger than the actual value when noise is not superimposed, and unnecessary braking is performed. It is possible to prevent the liquid pressure from being reduced.

Further, as shown in FIG. 9, noise is superimposed on the wheel speed sensor, and the wheel speed calculated from the signal of the wheel speed sensor on the same wheel is predetermined to the estimated vehicle speed calculated in the previous control cycle, for example. A system for measuring the time in a state of being equal to or more than a value obtained by adding the value b, setting the SD flag when the measurement time ΔTAi becomes a predetermined value β or more, for example, 1 to 2 seconds or more, and prohibiting ABS control of all wheels The system down is not canceled unless the system is down and a predetermined process is not performed. From this, not only external noise but also the failure of the wheel speed sensor and the peripheral portion of the sensor causes the calculated estimated vehicle body speed to be higher than the normal value, resulting in unnecessary reduction of the brake fluid pressure. Can be prevented. As described above, in the ABS control device,
Greatly improve safety and reliability.

Next, in the first operation example, when the wheel speed calculated from the signal of the wheel speed sensor detects a sudden increase which is not normally considered in one control cycle, the abnormality flag is set, and thereafter, Even when the noise is no longer superimposed on the wheel speed sensor, the abnormality flag remains set, but when noise is superimposed on the wheel speed sensor, the abnormality flag is set for a predetermined time and the abnormality flag is displayed. The wheel speed calculated from the wheel speed sensor of the wheel may be excluded from the calculation of the estimated vehicle speed, and the estimated vehicle speed may be calculated from the calculated wheel speeds of the remaining wheels. Examples 2 and 3 are shown in FIG.
0 and the flowchart of FIG. 11 will be replaced with the third operation example in the embodiment of the present invention.

FIGS. 10 and 11 are flow charts showing a third operation example in the embodiment of the apparatus of the present invention shown in FIG. 1. With reference to FIGS. 10 and 11, the apparatus of FIG.
In particular, a third operation example in the abnormality detection unit 4 will be described. 10 and 11, the same flows as those in FIGS. 2 and 3 are denoted by the same reference numerals, and the description thereof will be omitted here, and only the differences from the flowcharts of FIGS. 2 and 3 will be described.

10 and 11 are different from FIGS. 2 and 3 in that the processes of steps S60 and S61 are added between steps S13 and S11 of FIG. 2 and that of step S11 of FIG. And step S in FIG.
15 is that the processes of step S62 and step S63 have been added. Furthermore, the process of step S64 is added between step S17 and step S18 of FIG.

In FIG. 10, the abnormality detecting section 4 proceeds to step S60 after performing the processing of step S13, and in step S60, counts down the time during which the abnormality flag is set for each wheel and performs a countdown. Whether the current counter value CTBi in a timer TBi (not shown) having a counter is less than a predetermined value CT0, that is, whether the current measurement time ΔTBi of the timer TBi is less than the predetermined time T0. When the timer TBi starts counting down and the ΔTBi is less than the predetermined value T0 (YE
S), the process proceeds to step S61, the timer TBi is set to a predetermined value T0 in step S61, and the process proceeds to step S11. If the timer TBi is greater than or equal to the predetermined value T0 in step S60 (NO), the process proceeds to step S11. When one control cycle time is e, the relationship CTBi = ΔTBi / e holds in the counter value CTBi.

Further, the abnormality detecting section 4 carries out step S11.
Then, it is checked whether or not the counter value of the abnormality number counter FCi is less than the predetermined value α, and the counter value is determined to be the predetermined value α.
If it is less than (YES), the process proceeds to step S62, and the current time ΔTBi of the timer TBi is 0 in step S62.
It is checked whether or not the current time ΔTBi is not 0 (Y
ES), and proceeds to step S15 in FIG. Step S6
If the current time ΔTBi is 0 in 2 (NO), the abnormality flag Fi is reset and cleared in step S63, and the process proceeds to step S15 in FIG.

In FIG. 11, the abnormality detecting section 4 sets the wheel speed SPEEDi to the fastest wheel speed VH in step S17, then decrements the counter value CTBi of the timer TBi in step S64, and proceeds to step S18. .
If the abnormality flag Fi is not cleared in step S15 (NO), or if the fastest wheel speed VH at the present time is equal to or higher than the current wheel speed SPEEDi in step S16 (NO), the process proceeds to step S64.
If the counter value of the index counter i is not 5 in step S19 (NO), step S of FIG.
Return to 10. Also, after performing the process of step S27,
It returns to step S3 of FIG.

FIG. 12 is a diagram showing the relationship between the wheel speed SPEEDi, the estimated vehicle body speed, the abnormality flag Fi and the time ΔTBi indicated by the counter value CTBi of the timer TBi in the third operation example of the present embodiment. When noise is superimposed on the wheel speed sensor for some reason, it is rare that the noise actually ends up only once, and in many cases noise of a level that does not lead to abnormality detection is superimposed multiple times. Therefore, in the third embodiment
In the operation example, as shown in FIG. 12, noise is superimposed on the wheel speed sensor, and the wheel speed calculated from the signal of the wheel speed sensor is
For example, when one control cycle is 8 msec, when one control cycle shows a sudden rise that is not considered normally, such as an increase of 10 to 15 km / h or more, the abnormality is detected and a predetermined time, for example, 50 ms. The abnormality flag is set for up to 300 ms to indicate the wheel speed abnormality.

Further, the wheel speed calculated from the wheel speed sensor of the wheel indicated by the abnormality flag is excluded from the calculation of the estimated vehicle speed, and the estimated vehicle speed is calculated from the calculated wheel speeds of the remaining wheels. It is something that is done. From this, even if noise is superimposed on the wheel speed sensor multiple times, the calculated estimated vehicle body speed becomes larger than the actual value when noise is not superimposed, and unnecessary brake fluid pressure reduction occurs. Can be prevented. In addition, when the vehicle moves away from noise sources while driving,
When the noise is no longer superimposed on the wheel speed sensor, it is possible to quickly return to the normal processing.

As shown in FIG. 5 similarly to the first operation example, when the wheel speed calculated from the signal of the wheel speed sensor shows a sudden increase which cannot be usually considered in the same wheel, When an abnormality is detected and the number of times the abnormality is detected reaches a predetermined number, for example, 50 to 60 times, the SD flag is set, the system is down to prohibit the ABS control of all wheels, and the predetermined processing is not performed. As long as the system down is not released. From this, not only external noise but also the failure of the wheel speed sensor and the peripheral portion of the sensor causes the calculated estimated vehicle body speed to be higher than the normal value, resulting in unnecessary reduction of the brake fluid pressure. Can be prevented. As above, ABS
In the control device, the safety and reliability can be greatly improved.

Next, in the third operation example, when the wheel speed calculated from the signal of the wheel speed sensor detects an abrupt increase which is not normally considered in one control cycle, the abnormality flag is set for a predetermined time. Then, the wheel speed calculated from the wheel speed sensor of the wheel indicated by the abnormality flag is excluded from the calculation of the estimated vehicle speed, and the estimated vehicle speed is calculated from the calculated wheel speeds of the remaining wheels. However, the time for setting the abnormality flag may be set according to the magnitude of the noise superimposed on the wheel speed sensor, and FIG. 10 of the third operation example described above is replaced with the flowchart of FIG. The fourth operation example in FIG.

FIGS. 13 and 11 are flow charts showing a fourth operation example in the embodiment of the apparatus of the present invention shown in FIG. 1. FIG. 13 is used to explain the apparatus of FIG. A fourth operation example in the above will be described. Note that in FIG. 13, the same flows as those in FIG. 10 are denoted by the same reference numerals, and the description thereof will be omitted and only the differences from the flowchart of FIG. 10 will be described. 13 is different from FIG. 10 in that the process of making the determination in step S60 of FIG. 10 is replaced with the process of making the determination in step S70.
Further, the process of step S61 in FIG. 7 is replaced with the process of step S71.

In FIG. 13, after performing the processing of step S13, the abnormality detection unit 4 determines in step S70 that the current counter value CTBi of the timer TBi is ΔSPEEDi in the current control cycle, for example, 5 to 60. Set time Tk (Tk = k ×
ΔSPEEDi) is less than the counter value CTk, that is, the current measurement time ΔTBi of the timer TBi.
Is less than the above set time Tk, the timer TB
When i starts counting down and the measured time ΔTBi is less than the set time Tk (YES), the process proceeds to step S71,
In step S71, the measurement time ΔTBi is set to the set time Tk.
, And the process proceeds to step S11.

FIG. 14 shows the time ΔTBi indicated by the wheel speed SPEEDi, the estimated vehicle speed, the abnormality flag Fi and the counter value CTBi of the timer TBi in the fourth operation example of this embodiment.
FIG. When noise is superimposed on the wheel speed sensor for some reason, it is rare that the noise actually ends up only once, and in many cases noise of a level that does not lead to abnormality detection is superimposed multiple times. In addition, the magnitude of each noise is often not constant. For example, for a noise source,
The noise superimposed on the wheel speed sensor gradually increases as the vehicle approaches, and the noise superimposed on the wheel speed sensor gradually decreases as the vehicle moves away.

Therefore, the fourth operation example in this embodiment is as follows.
As shown in FIG. 14, when noise is superimposed on the wheel speed sensor and the wheel speed calculated from the signal from the wheel speed sensor is, for example, 8 msec in one control cycle, 10 to 1 in one control cycle.
When a sudden rise that is not normally considered, such as an increase of 5 km / h or more, is detected, the abnormality is detected and the previous control cycle calculated from the signal data from the wheel speed sensor in which the abnormality is detected. The abnormality flag is set during the time Tk set in accordance with the difference between the wheel speed of No. 1 and the wheel speed in the present control cycle to indicate the abnormality of the wheel speed.

Further, the wheel speed calculated from the wheel speed sensor of the wheel indicated by the abnormality flag is excluded from the calculation of the estimated vehicle speed, and the estimated vehicle speed is calculated from the calculated wheel speeds of the remaining wheels. It is something that is done. From this, even if noise is superimposed on the wheel speed sensor multiple times, the calculated estimated vehicle body speed becomes larger than the actual value when noise is not superimposed, and unnecessary brake fluid pressure reduction occurs. Can be prevented. In addition, when the vehicle moves away from noise sources while driving,
When the noise is no longer superimposed on the wheel speed sensor, it is possible to quickly return to the normal processing.

As shown in FIG. 5 similarly to the first operation example, when the wheel speed calculated from the signal of the wheel speed sensor shows a sudden increase which is not normally considered in the same wheel, When an abnormality is detected and the number of times the abnormality is detected reaches a predetermined number, for example, 50 to 60 times, the SD flag is set, the system is down to prohibit the ABS control of all wheels, and the predetermined processing is not performed. As long as the system down is not released. From this, not only external noise but also the failure of the wheel speed sensor and the peripheral portion of the sensor causes the calculated estimated vehicle body speed to be higher than the normal value, resulting in unnecessary reduction of the brake fluid pressure. Can be prevented. As above, ABS
In the control device, the safety and reliability can be greatly improved.

As described above, various modifications of the present invention are conceivable, and the scope of the present invention is not limited to the above-described embodiments, and it goes without saying that the scope of the present invention should be determined by the scope of the claims. .

[Brief description of drawings]

FIG. 1 is a schematic block diagram showing an embodiment of an antilock control device of the present invention.

FIG. 2 is a diagram showing a first half portion of a flowchart showing a first operation example in the embodiment of the apparatus of the present invention shown in FIG.

3 is a diagram showing the latter half of the flowchart showing the first operation example in the embodiment of the apparatus of the present invention shown in FIG. 1. FIG.

FIG. 4 is a wheel speed in a first operation example of the present embodiment,
It is a figure showing the relation between estimated vehicle speed and abnormality flag Fi.

FIG. 5 is a wheel speed in a first operation example of the present embodiment,
FIG. 6 is a diagram showing a relationship between an estimated vehicle speed, a counter value of an abnormal number counter FCi, and an SD flag FSD.

FIG. 6 is a diagram showing the first half of a flowchart showing a second operation example in the embodiment of the apparatus of the present invention shown in FIG. 1.

7 is a diagram showing the latter half of the flowchart showing the second operation example in the embodiment of the apparatus of the present invention shown in FIG.

FIG. 8 is a wheel speed in a second operation example of the present embodiment,
It is a figure showing the relation between estimated vehicle speed and abnormality flag Fi.

FIG. 9 is a wheel speed in a second operation example of the present embodiment,
FIG. 6 is a diagram showing a relationship among an estimated vehicle speed, an abnormality flag Fi, a measurement time ΔTAi of an abnormality timer TAi, and an SD flag FSD.

FIG. 10 is a diagram showing a first half portion of a flowchart showing a third operation example in the embodiment of the apparatus of the present invention shown in FIG. 1.

11 is a diagram showing the latter half of the flowchart showing the third operation example in the embodiment of the apparatus of the present invention shown in FIG. 1. FIG.

FIG. 12 is a diagram showing a relationship among a wheel speed, an estimated vehicle body speed, an abnormality flag Fi, and a measurement time ΔTBi of a timer TBi in a third operation example of the present embodiment.

FIG. 13 is a diagram showing a first half portion of a flowchart showing a fourth operation example in the embodiment of the apparatus of the present invention shown in FIG. 1.

FIG. 14 is a diagram showing a relationship among a wheel speed, an estimated vehicle body speed, an abnormality flag Fi, and a measurement time ΔTBi of a timer TBi in a fourth operation example of the present embodiment.

FIG. 15 is an estimated vehicle speed when noise continues to be superimposed on a wheel speed sensor when a conventional device is used,
FIG. 7 is a diagram showing an estimated vehicle body speed when noise is not superimposed.

[Explanation of symbols]

 1 ABS control device 2a, 2b, 2c, 2d Wheel speed sensor 3 Wheel speed and wheel deceleration calculation unit 4 Abnormality detection unit 5 Estimated vehicle speed calculation unit 6 Wheel state detection unit 7 Hydraulic pressure control device drive unit 8 Control prohibition unit 9 Liquid pressure controller

Claims (7)

[Claims] 1. At least one wheel speed detecting means for detecting a speed of each wheel, a wheel speed calculating means for calculating a wheel speed of a wheel from a signal from the wheel speed detecting means, and a wheel speed calculating means for calculating the wheel speed. In an anti-lock control device having an estimated vehicle body speed calculating means for calculating an estimated vehicle body speed from the wheel speeds of the respective wheels, an abnormality in the wheel speed of each wheel is detected, and when an abnormality in the wheel speed is detected, For the estimated vehicle speed calculation means,
An anti-lock control device comprising an abnormality detection means for calculating the estimated vehicle body speed from the wheel speeds of the wheels other than the wheel speed of the wheel. 2. The antilock control device according to claim 1, wherein the abnormality detecting means is configured such that, for the same wheel, the wheel speed calculated in the current control cycle is more than the wheel speed calculated in the previous control cycle. Also becomes larger than a predetermined value, the current wheel speed of the wheel is judged to be abnormal, and the estimated vehicle body speed calculation means is instructed to the estimated vehicle body speed calculation means until each wheel of the other wheels except the wheel speed of the wheel. An anti-lock control device characterized in that an estimated vehicle speed in the current control cycle is calculated from the speed. 3. The antilock control device according to claim 1, wherein the abnormality detecting means is configured such that, for the same wheel, the wheel speed calculated in the current control cycle is more than the wheel speed calculated in the previous control cycle. Is also greater than a predetermined value, the estimated vehicle body speed in the present control cycle is calculated from the wheel speeds of other wheels excluding the wheel speed of the wheel to the estimated vehicle speed calculation means for a predetermined time. An anti-lock control device characterized by: 4. The antilock control device according to any one of claims 1 to 3, wherein the abnormality detecting means comprises:
When calculating the estimated vehicle body speed with respect to the estimated vehicle body speed calculating means, the time excluding the wheel speed determined to be abnormal is excluded from the wheel speed calculated in the current control cycle and the wheel calculated in the previous control cycle. An anti-lock control device that is set according to the deviation from the speed. 5. The antilock control device according to any one of claims 1 to 4, wherein the abnormality detecting means comprises:
When the wheel speed abnormality of the same wheel is detected a predetermined number of times, it is determined that the wheel speed detecting means is abnormal, and the ABS control of all the wheels is prohibited, and the ABS control is prohibited until a predetermined restoration process is performed. An anti-lock control device characterized by not releasing. 6. The antilock control device according to claim 1, wherein the abnormality detecting means is configured such that, for the same wheel, the wheel speed calculated in the current control cycle is more than the wheel speed calculated in the previous control cycle. Also, after detecting that the wheel speed is greater than a predetermined value, the estimated vehicle speed calculation means until the wheel speed becomes a value within a predetermined range with respect to the estimated vehicle speed calculated by the estimated vehicle speed calculation means. An antilock control device, characterized in that an estimated vehicle body speed in a current control cycle is calculated from the wheel speeds of other wheels excluding the wheel speed of the wheel. 7. The antilock control device according to claim 6, wherein the abnormality detecting means determines that the wheel speed detecting means is abnormal when an abnormality in the wheel speed of the same wheel is detected for a predetermined time or more, An antilock control device, characterized in that the ABS control of all wheels is prohibited, and the ABS control prohibition is not released until a predetermined restoration process is performed.