JPH07306217A - Wheel speed detector and wheel slip controller - Google Patents

Abstract

PURPOSE:To determine noise surely by making such a decision that noise is generated due to fluctuation in the external field when a wheel sensor starts to output a pulse signal and the period from the start of the output until a predetermined number of times of the output corresponds to a frequency within a predetermined range. CONSTITUTION:The speed detector for detecting the wheel speed of respective wheels comprises wheel speed sensors 26-29 each converting the variation of flux into the variation of voltage. The sensors 26-29 are affected by magnetic field variation if a significant variation of external magnetic field occur and noise appears in the output signal. When the sensor 26-29 starts to output a pulse signal in normal noiseless state, the number pf pulses increases gradually at first with a short period. A decision is then made whether the period of pulse signal corresponds to an abnormal high frequency before the pulse signals are outputted by a predetermined number of times thus deciding whether an output signal represents a noise caused by the fluctuation in the external magnetic field.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheel speed detecting device and a wheel slip control device, and more particularly to a wheel speed detecting device equipped with a so-called electromagnetic pickup type wheel speed sensor,
The present invention also relates to a wheel slip control device including such a wheel speed detection device.

[0002]

2. Description of the Related Art Conventionally, as a wheel speed detecting device for detecting the speed of each wheel in a vehicle such as an automobile, a so-called electromagnetic pickup type which converts a change in magnetic flux into a voltage signal and outputs a pulsed output signal is known. Those equipped with the wheel speed sensor are generally widely used. This type of wheel speed detection device uses the rotation of a gear-shaped (or sawtooth-shaped) rotation detection plate (tooth-shaped rotor) that rotates integrally with the wheel as an electromagnetic pickup (wheel The wheel speed sensor is provided with, for example, a permanent magnet and a coil for voltage generation, and the tooth portion passes in the vicinity of the pickup portion as the rotor rotates. The magnetic flux changes in the voltage generating coil, and the voltage signal is output accordingly. Then, in this case, the voltage signal is output in a pulse shape each time the tooth portion passes in the vicinity of the pickup portion as the tooth-shaped rotor rotates.

The detection data obtained by such a wheel speed detecting device is used for so-called anti-skid control device for preventing the occurrence of a locked or skid state of each wheel during vehicle braking, and for suppressing slippage of driving wheels during vehicle running. In a vehicle equipped with a control device such as a so-called traction control device that can control the slip state of the wheels, it is used as basic input information for performing these controls. That is, in the case of anti-skid control, for example, the acceleration / deceleration of each wheel is calculated based on the wheel speed data obtained by the wheel speed detection device, and the pseudo vehicle body of the vehicle is also estimated based on the wheel speed data. The slip ratio of the wheel can be calculated from the speed and the wheel speed, and the occurrence of wheel lock can be detected by comparing this slip ratio with a preset threshold value. Then, depending on whether or not the wheels are locked, a series of controls for decreasing or increasing the braking force for each wheel is repeatedly executed until the vehicle stops, for example. In the case of traction control,
Basically, the speed difference between the driving wheel and the driven wheel is calculated from the wheel speed data of each wheel, and when the speed difference exceeds a preset threshold value, for example, the power given to the driving wheel such as reducing the engine output. Is controlled or a braking force is applied to the driving wheels.

By the way, since the electromagnetic pickup type wheel speed sensor converts the magnetic flux change into a voltage signal and outputs the signal as described above, when there is a large change in the external magnetic field, this change occurs. May be affected by. That is, a change in the external magnetic field may be input as external noise, which may affect the accuracy and reliability of the detection result. Regarding such a noise problem, for example, JP-A-60-25836 and JP-A-62-255871.
Japanese Patent Laid-Open Publication No. 2005-242242 discloses a method in which the noise determination is performed by comparing the difference between the current calculated value and the previous calculated value of the wheel speed with a reference value. Although not particularly conscious of external noise, for example, in Japanese Patent Laid-Open No. 63-172967, the period of each pulse signal is compared with the previous pulse period to determine an abnormality, and an abnormal pulse period is detected. It is disclosed that the correction is performed based on the relationship with the previous pulse period.

[0005]

A railway vehicle, for example, can be considered as a device that causes a large change in the external magnetic field that can affect the wheel speed detecting device of a moving automobile. That is, the power system of the railway vehicle is driven with a large value of current, and when such a railway vehicle passes near the automobile equipped with the wheel speed detecting device, the external magnetic field of the wheel speed detecting device changes greatly. Is brought about. In this case, in the case of an ordinary railway vehicle, the current supplied to its drive system is direct current, so the change in the external magnetic field does not have periodicity, and there is no particular effect on the detection of wheel speed. Not considered. However, in the case of the Shinkansen, a large current of AC 60 Hz (Hertz) is usually used, and when passing this, a magnetic field change of a cycle of 60 Hz is brought about.

For this reason, for example, when a road passes over an elevated Shinkansen, and a car is stopped or traveling at a very low speed on this road, when the Shinkansen passes under the road, 60 Hz There is a problem that the AC magnetic field acts on the wheel speed detection device and is superimposed on the detection signal as external noise. In this case, the frequency of noise is constant (60 Hz), but its strength (magnitude) changes depending on the magnitude of the power load of the Shinkansen vehicle. On the other hand, as the electromagnetic pickup type wheel speed detecting device,
A toothed rotor having a number of teeth of 44 is generally widely used, and in the case of this number of teeth, a magnetic field change caused by an alternating current of 60 Hz corresponds to about 9 km / hr in terms of speed. Therefore, the wheel speed detection device outputs a voltage signal on which noise corresponding to the speed of about 9 km / hr is superimposed as the Shinkansen vehicle passes.

In this case, if the traveling speed of the automobile is high to some extent, the original signal level output from the wheel speed sensor is high (the output is high), so even if the above noise is superimposed, the detected value of the wheel speed is Although it is unlikely to exert any influence, the influence of the noise becomes great when the automobile is stopped or traveling at a very low speed. That is, the vehicle itself actually stops traveling (vehicle speed 0 km / hr) or travels at an extremely low vehicle speed, but the wheel speed detection device detects the wheel speed of 9 km / hr as noise.

The intensity (magnitude) of this noise changes depending on the magnitude of the power load of the Shinkansen vehicle as described above. The signal level read by the anti-skid control device is predetermined, and the anti-skid control device reads or does not read the noise signal of 9 km / hr depending on the magnitude relationship between the read signal level and the noise level. In other words, 9km
The noise signal of / hr may or may not be input to the anti-skid controller side. And this 9
If a noise signal of km / hr is input to the anti-skid control device side and then this signal is not input, it is assumed that the wheel speed has been rapidly reduced from 9 km / hr to 0 (zero) km / hr. There is a problem that the driver may feel uncomfortable because the anti-skid control may be performed in an unexpected driving state because the control may start to be executed.

To solve this problem, however, by changing the number of teeth of the tooth profile rotor combined with the wheel speed sensor of the wheel speed detecting device from the normal 44 to, for example, 90, the wheel speed corresponding to AC 60 Hz is obtained. It is conceivable to make a change so as not to affect the execution of the anti-skid control. That is, the antiskid controller is
Generally, if the wheel speed is 5 km / hr or less, it is set not to enter the control, while the number of teeth of the tooth profile rotor is set to 9
When set to 0, AC 60Hz is about 4.5km in terms of speed.
/ Hr, so even if this noise signal is input,
The execution of anti-skid control is never started. However, in this case, it is necessary to fundamentally change the manufacturing process of the above-mentioned tooth profile rotor, including the manufacture of the die, and there is a problem that the cost is significantly increased.

Further, depending on the direction of the wheel speed sensor attached to each wheel and the direction of the magnetic field generated by the passage of the Shinkansen, noise may occur only on the front wheel side or only on the rear wheel side due to changes in the external magnetic field. However, when the traction control device is installed in the vehicle, for example, if the vehicle is of the rear-wheel drive type, if noise occurs only on the rear wheel side, the drive wheel and the driven wheel are affected by this noise. The speed difference between the vehicle and the vehicle will appear larger than it actually is, and it is conceivable that the traction control will be started if the speed difference exceeds a preset threshold. Since the control is performed, there is a problem that the user feels something strange.

The present invention has been made in view of the above-mentioned problems, and in a wheel speed detecting device equipped with an electromagnetic pickup type wheel speed sensor, noise caused by a change in an external magnetic field is generated without causing a significant increase in cost. It is an object of the present invention to reliably determine that the wheel slip control device is equipped with such a wheel speed detection device and to prevent the wheel slip control from being performed in an unexpected driving state by the driver.

[0012]

Therefore, the invention according to claim 1 of the present application (hereinafter referred to as the first invention) converts the magnetic flux change into a voltage signal, and changes the frequency corresponding to the frequency of the magnetic flux change. A wheel speed detection device that includes an electromagnetic pickup type wheel speed sensor that outputs a pulse signal, and detects a wheel speed based on an output signal from the wheel speed sensor,
When the wheel speed sensor outputs a pulse signal from the non-pulse state, when the pulse cycle from the start of output to a predetermined number of times corresponds to a frequency in a predetermined range, the output signal from the wheel speed sensor changes the external magnetic field. It is determined that the noise is due to noise.

The invention according to claim 2 of the present application (hereinafter,
The second invention) includes an electromagnetic pickup type wheel speed sensor that converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. In the wheel speed detecting device for detecting the wheel speed based on, the wheel speed sensor is attached to each of the four wheels of the vehicle, and the wheel speed sensors of all four wheels are pulseless,
For at least one wheel speed sensor, when a pulse signal corresponding to a frequency within a predetermined range of the pulse cycle from the start of output to a predetermined number of times is output, the output signal from each wheel speed sensor changes the external magnetic field. It is determined that the noise is due to noise.

The invention according to claim 3 of the present application (hereinafter,
The third invention) is provided with an electromagnetic pickup type wheel speed sensor that converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. In the wheel speed detecting device for detecting the wheel speed based on, the wheel speed sensor is attached to each of the four wheels of the vehicle, and the wheel speed sensors of all four wheels are pulseless,
For a plurality of wheel speed sensors of a predetermined number or more (for example, two or more), when a pulse signal corresponding to a frequency within a predetermined range of the pulse cycle from the start of output to a predetermined number of times is output, each of the wheel speed sensors outputs The output signal of is determined to be noise due to a change in the external magnetic field.

Furthermore, the invention according to claim 4 of the present application (hereinafter,
In a fourth aspect of the invention, in any one of the first to third aspects of the invention, the pulse cycle from the start of output to a predetermined number of times is a cycle of rising and falling of the first pulse from a non-pulse state. It is characterized by being.

The invention according to claim 5 of the present application
(Hereinafter, referred to as a fifth invention) includes an electromagnetic pickup type wheel speed sensor that converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. In the wheel speed detection device for detecting the wheel speed based on the output signal of, after the pulse signal of the frequency of the predetermined range is continuously output from the wheel speed sensor for a certain period of time, it becomes a pulseless state, and this pulseless state is When it is continued for a predetermined time or longer, the output signal from the wheel speed sensor is determined to be noise due to a change in the external magnetic field.

Furthermore, the invention according to claim 6 of the present application.
(Hereinafter, referred to as a sixth invention) includes an electromagnetic pickup type wheel speed sensor that converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. In the wheel speed detecting device for detecting the wheel speed based on the output signal of the vehicle, the wheel speed sensor is attached to each of the four wheels of the vehicle, and the wheel speed of at least one of the four wheel speed sensors. Regarding the sensor, after the pulse signal of the frequency in the predetermined range is continuously output for a certain period of time, it becomes the non-pulse state, and when the non-pulse state is continued for the predetermined period of time or more, the output signal from each wheel speed sensor is externally output. It is determined that the noise is caused by a change in the magnetic field.

Furthermore, the invention according to claim 7 of the present application.
(Hereinafter, referred to as a seventh invention) includes an electromagnetic pickup type wheel speed sensor that converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. In the wheel speed detecting device for detecting the wheel speed based on the output signal of the vehicle, the wheel speed sensor is attached to each of the four wheels of the vehicle.
For (for example, two or more) wheel speed sensors, after pulse signals of frequencies within a predetermined range are continuously output for a certain period of time,
When the pulse-free state is maintained and the pulse-free state continues for a predetermined time or longer, the output signal from each wheel speed sensor is determined to be noise due to a change in the external magnetic field.

Furthermore, the invention according to claim 8 of the present application.
(Hereinafter, referred to as an eighth invention), in any one of the first to seventh inventions, the frequency in the predetermined range is 50 to 6
It is characterized by being 0 Hz.

Further, the invention according to claim 9 of the present application
(Hereinafter, referred to as a ninth invention) includes an electromagnetic pickup-type wheel speed sensor that converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. In the wheel speed detecting device for detecting the wheel speed based on the output signal of the wheel speed sensor, it is determined that the output signal from the wheel speed sensor is noise due to the change of the external magnetic field, When the pulse signal corresponding to the speed of is output for a certain period of time or more, the noise determination is canceled.

Further, the invention according to claim 10 of the present application
(Hereinafter, referred to as the tenth invention) includes an electromagnetic pickup type wheel speed sensor that converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. In the wheel speed detecting device for detecting the wheel speed based on the output signal of the vehicle, the wheel speed sensors are attached to each of the four wheels of the vehicle, and the output signals from the wheel speed sensors are noises due to changes in the external magnetic field. After it is determined that the above, the noise determination is canceled when the wheel speed sensors of all the four wheels continue to be in the non-pulse state for a certain time or longer.

The invention according to claim 11 of the present application (hereinafter referred to as the eleventh invention) is an electromagnetic pickup which converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. Wheel speed detecting device for detecting the wheel speed based on the output signal from the wheel speed sensor of the formula, hydraulic adjusting means for adjusting the braking pressure of each wheel, and based on the wheel speed detected by the wheel speed detecting device. In a wheel slip control device having an anti-skid control means for periodically increasing or decreasing the braking pressure of each wheel by operating the hydraulic pressure adjusting means, when the wheel speed sensor outputs a pulse signal from a non-pulse state. , When the period of the pulse from the start of output to the predetermined number of times corresponds to the frequency in the predetermined range, the output signal from the wheel speed sensor is It is obtained so as to be determined as noise by reduction.

Furthermore, the invention according to claim 12 of the present application (hereinafter referred to as the twelfth invention) is an electromagnetic pickup which converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. Wheel speed detecting device for detecting the wheel speed based on the output signal from the wheel speed sensor of the formula, hydraulic adjusting means for adjusting the braking pressure of each wheel, and based on the wheel speed detected by the wheel speed detecting device. In a wheel slip control device including anti-skid control means for periodically increasing / decreasing a braking pressure of each wheel by operating the hydraulic pressure adjusting means, the wheel speed sensor is attached to each of four wheels of a vehicle. Therefore, from the state in which the wheel speed sensors of all four wheels are pulseless, at least one wheel speed sensor is output a predetermined number of times from the start of output. When the pulse signal period of the pulse corresponding to the frequency of the predetermined range is output, the output signals from the wheel speed sensors are those to be determined that the noise due to changes in the external magnetic field.

Further, the invention according to claim 13 of the present application (hereinafter referred to as the thirteenth invention) is an electromagnetic pickup which converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. Wheel speed detecting device for detecting the wheel speed based on the output signal from the wheel speed sensor of the formula, hydraulic adjusting means for adjusting the braking pressure of each wheel, and based on the wheel speed detected by the wheel speed detecting device. In a wheel slip control device including anti-skid control means for periodically increasing / decreasing a braking pressure of each wheel by operating the hydraulic pressure adjusting means, the wheel speed sensor is attached to each of four wheels of a vehicle. Therefore, the output of the wheel speed sensors of a predetermined number or more (for example, two or more) is output from the state in which the wheel speed sensors of all four wheels are pulseless. When a pulse signal corresponding to a frequency within a predetermined range of the pulse cycle from the beginning to a predetermined number of times is output, the output signal from each wheel speed sensor is determined to be noise due to a change in the external magnetic field. It is a thing.

Further, the invention according to claim 14 of the present application
(Hereinafter, referred to as a 14th invention), in any one of the 11th to 13th inventions, a period of a pulse from the start of output to a predetermined number of times is a rising edge and a rising edge of a first pulse from a non-pulse state. It is characterized by a falling cycle.

Further, the invention according to claim 15 of the present application
(Hereinafter, referred to as a fifteenth invention) is a wheel based on an output signal from an electromagnetic pickup type wheel speed sensor that converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. A wheel speed detecting device for detecting the speed, a hydraulic pressure adjusting means for adjusting the braking pressure of each wheel,
A slip control device for a wheel, comprising: an anti-skid control means for periodically increasing or decreasing the braking pressure of each wheel by operating the hydraulic pressure adjusting means based on the wheel speed detected by the wheel speed detecting device, After a pulse signal of a frequency within a predetermined range is continuously output from the wheel speed sensor for a certain period of time, the pulse signal becomes a pulseless state. When the pulseless state continues for a predetermined period of time or more, the output signal from the wheel speed sensor is external It is determined that the noise is caused by a change in the magnetic field.

Furthermore, the invention according to claim 16 of the present application.
(Hereinafter, referred to as a sixteenth invention) is a wheel based on an output signal from an electromagnetic pickup type wheel speed sensor that converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. A wheel speed detecting device for detecting the speed, a hydraulic pressure adjusting means for adjusting the braking pressure of each wheel,
A slip control device for a wheel, comprising: an anti-skid control means for periodically increasing or decreasing the braking pressure of each wheel by operating the hydraulic pressure adjusting means based on the wheel speed detected by the wheel speed detecting device, A wheel speed sensor is attached to each of the four wheel speeds of the vehicle, and at least one of the four wheel speed sensors outputs a pulse signal having a frequency in a predetermined range continuously for a certain period of time. After that, the pulseless state is established, and when this pulseless state is continued for a predetermined time or longer, the output signal from each wheel speed sensor is determined to be noise due to a change in the external magnetic field.

The invention according to claim 17 of the present application
(Hereinafter, referred to as a seventeenth invention) is a wheel based on an output signal from an electromagnetic pickup type wheel speed sensor which converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. A wheel speed detecting device for detecting the speed, a hydraulic pressure adjusting means for adjusting the braking pressure of each wheel,
A slip control device for a wheel, comprising: an anti-skid control means for periodically increasing or decreasing the braking pressure of each wheel by operating the hydraulic pressure adjusting means based on the wheel speed detected by the wheel speed detecting device, A wheel speed sensor is attached to each of the four wheels of the vehicle, and a predetermined number or more of these four wheel speed sensors are attached.
For (for example, two or more) wheel speed sensors, after pulse signals of frequencies within a predetermined range are continuously output for a certain period of time,
When the pulseless state is maintained and the pulseless state is continued for a predetermined time or longer, the output signal from each wheel speed sensor is determined to be noise due to a change in the external magnetic field.

Further, the invention according to claim 18 of the present application
(Hereinafter, referred to as 18th invention), in any one of the 11th to 17th inventions, the frequency in the predetermined range is 5
It is characterized by being 0 to 60 Hz.

The invention according to claim 19 of the present application
(Hereinafter, referred to as a nineteenth invention) is a wheel based on an output signal from a wheel speed sensor of an electromagnetic pickup type which converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. A wheel speed detecting device for detecting the speed, a hydraulic pressure adjusting means for adjusting the braking pressure of each wheel,
A slip control device for a wheel, comprising: an anti-skid control means for periodically increasing or decreasing the braking pressure of each wheel by operating the hydraulic pressure adjusting means based on the wheel speed detected by the wheel speed detecting device, After it is determined that the output signal from the wheel speed sensor is noise due to a change in the external magnetic field, when a pulse signal corresponding to a speed equal to or higher than a predetermined wheel speed is output from the wheel speed sensor for a certain period of time or more, The noise determination is canceled.

Further, the invention according to claim 20 of the present application
(Hereinafter, referred to as twentieth invention) is a wheel based on an output signal from an electromagnetic pickup type wheel speed sensor which converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. A wheel speed detecting device for detecting the speed, a hydraulic pressure adjusting means for adjusting the braking pressure of each wheel,
A slip control device for a wheel, comprising: an anti-skid control means for periodically increasing or decreasing the braking pressure of each wheel by operating the hydraulic pressure adjusting means based on the wheel speed detected by the wheel speed detecting device, A wheel speed sensor is attached to each of the four wheels of the vehicle, and after it is determined that the output signal from the wheel speed sensor is noise due to a change in the external magnetic field, the wheel speed sensors of all the four wheels are constant. The above noise determination is canceled when the non-pulse state is continued for a time or longer.

The invention according to claim 21 of the present application (hereinafter referred to as the twenty-first invention) is the wheel slip control device according to any one of the eleventh to twentieth inventions. When it is determined that the output signal from the wheel speed sensor is noise due to the change in the external magnetic field when estimating the pseudo vehicle body speed of the vehicle based on the wheel speed detected by the device, this noise determination During the period, the increase in the estimated value of the pseudo vehicle body speed is limited.

Further, the invention according to claim 22 of the present application (hereinafter referred to as the twenty-second invention) is the wheel slip control device according to any one of the eleventh to twentieth inventions. When it is determined that the output signal from the wheel speed sensor is noise due to the change in the external magnetic field when estimating the pseudo vehicle body speed of the vehicle based on the wheel speed detected by the device, this noise determination During the period, the pseudo vehicle body speed is estimated to be 0 km / hr.

Further, the invention according to claim 23 of the present application (hereinafter referred to as the 23rd invention) is the wheel slip sensor according to any one of the 11th to 20th inventions, wherein the wheel slip control device is the wheel speed sensor. When it is determined that the output signal from is noise due to a change in the external magnetic field, during this noise determination period, it is necessary to increase the minimum value of the wheel speed for performing the anti-skid control by a predetermined amount. It is a feature.

The invention according to claim 24 of the present application
(Hereinafter, referred to as a twenty-fourth invention.) In any one of the eleventh to twentieth inventions, in the slip control device for a wheel, an output signal from the wheel speed sensor is noise due to a change in an external magnetic field. If it is determined that during the noise determination period, the control threshold value for starting the anti-skid control is changed to the side that is hard to enter the control.

The invention according to claim 25 of the present application
(Hereinafter, referred to as 25th invention) In any one of the 11th to 20th inventions, in the slip control device for the wheel, an output signal from the wheel speed sensor is noise due to a change in an external magnetic field. When it is determined that the anti-skid control is started during the noise determination period, the start of the anti-skid control is prohibited.

The invention according to claim 26 of the present application (hereinafter referred to as the twenty-sixth invention) is an electromagnetic pickup which converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. Wheel speed detection device for detecting the wheel speed based on the output signal from the wheel speed sensor of the formula, and calculates the speed difference between the drive wheel and the driven wheel based on the wheel speed detected by the wheel speed detection device, When the calculated value exceeds a predetermined value, in a wheel slip control device including traction control means for performing at least one of control for applying a braking force to the drive wheels and control for reducing the engine output, When the wheel speed sensor outputs a pulse signal from the non-pulse state, the pulse cycle from the start of output to a predetermined number of times corresponds to a frequency in a predetermined range. The output signal from the wheel speed sensors are those to be determined that the noise due to changes in the external magnetic field.

Furthermore, the invention according to claim 27 of the present application (hereinafter referred to as the 27th invention) is an electromagnetic pickup which converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. Wheel speed detection device for detecting the wheel speed based on the output signal from the wheel speed sensor of the formula, and calculates the speed difference between the drive wheel and the driven wheel based on the wheel speed detected by the wheel speed detection device, When the calculated value exceeds a predetermined value, in a wheel slip control device including traction control means for performing at least one of control for applying a braking force to the drive wheels and control for reducing the engine output, The wheel speed sensor is attached to each of the four wheels of the vehicle, and at least one wheel is selected from the state in which the wheel speed sensors of all four wheels are pulseless. Regarding the wheel speed sensor, when a pulse signal corresponding to a frequency within a predetermined range of a pulse cycle from the start of output to a predetermined number of times is output, the output signal from each wheel speed sensor is noise due to a change in an external magnetic field. It is determined to be.

Furthermore, the invention according to claim 28 of the present application (hereinafter referred to as the twenty-eighth invention) is an electromagnetic pickup which converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. Wheel speed detection device for detecting the wheel speed based on the output signal from the wheel speed sensor of the formula, and calculates the speed difference between the drive wheel and the driven wheel based on the wheel speed detected by the wheel speed detection device, When the calculated value exceeds a predetermined value, in a wheel slip control device including traction control means for performing at least one of control for applying a braking force to the drive wheels and control for reducing the engine output, The above-mentioned wheel speed sensors are attached to each of the four wheels of the vehicle. From the state in which the wheel speed sensors of all four wheels are pulseless, a predetermined number of wheels With respect to (for example, two or more) wheel speed sensors, when a pulse signal corresponding to a frequency within a predetermined range of the pulse cycle from the start of output to a predetermined number of times is output, the output signal from each wheel speed sensor is externally output. It is determined that the noise is caused by a change in the magnetic field.

The invention according to claim 29 of the present application
(Hereinafter, referred to as a twenty-ninth invention), in any one of the twenty-sixth to twenty-eighth inventions, a period of a pulse from the start of output to a predetermined number of times is a rising edge and a rising edge of a first pulse from a non-pulse state. It is characterized by a falling cycle.

Furthermore, the invention according to claim 30 of the present application.
(Hereinafter, referred to as a thirtieth invention) is a wheel based on an output signal from an electromagnetic pickup type wheel speed sensor which converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. A wheel speed detecting device for detecting the speed, and a speed difference between the driving wheel and the driven wheel is calculated based on the wheel speed detected by the wheel speed detecting device. If the calculated value exceeds a predetermined value, In a wheel slip control device including a traction control unit that performs at least one of control for applying a braking force to a drive wheel and control for reducing an engine output, a pulse signal having a frequency in a predetermined range is output from the wheel speed sensor. After being continuously output for a certain period of time, it goes into a pulseless state. No. is obtained by to be determined that the noise due to changes in the external magnetic field.

Furthermore, the invention according to claim 31 of the present application.
(Hereinafter, referred to as a thirty-first invention) is a wheel based on an output signal from an electromagnetic pickup type wheel speed sensor which converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. A wheel speed detecting device for detecting the speed, and a speed difference between the driving wheel and the driven wheel is calculated based on the wheel speed detected by the wheel speed detecting device. If the calculated value exceeds a predetermined value, In a wheel slip control device including a traction control unit that performs at least one of a control for applying a braking force to a driving wheel and a control for reducing an engine output, the wheel speed sensor is provided for each of four wheels of a vehicle. Of these four wheel speed sensors, at least one wheel speed sensor has a pulse signal of a frequency within a predetermined range that continues for a certain period of time. After being output, it goes into a pulseless state, and when this pulseless state continues for a predetermined time or more, the output signal from each wheel speed sensor is determined to be noise due to a change in the external magnetic field. is there.

Further, the invention according to claim 32 of the present application
(Hereinafter, referred to as 32nd invention) is a wheel based on an output signal from an electromagnetic pickup type wheel speed sensor which converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. A wheel speed detecting device for detecting the speed, and a speed difference between the driving wheel and the driven wheel is calculated based on the wheel speed detected by the wheel speed detecting device. If the calculated value exceeds a predetermined value, In a wheel slip control device including a traction control unit that performs at least one of a control for applying a braking force to a driving wheel and a control for reducing an engine output, the wheel speed sensor is provided for each of four wheels of a vehicle. A plurality of wheel speed sensors for these four wheels are installed.
For (for example, two or more) wheel speed sensors, after pulse signals of frequencies within a predetermined range are continuously output for a certain period of time,
When the pulseless state is maintained and the pulseless state is continued for a predetermined time or longer, the output signal from each wheel speed sensor is determined to be noise due to a change in the external magnetic field.

The invention according to claim 33 of the present application
(Hereinafter, referred to as a 33rd invention), in any one of the 26th to 32nd inventions, the frequency within the predetermined range is 5
It is characterized by being 0 to 60 Hz.

Furthermore, the invention according to claim 34 of the present application.
(Hereinafter, referred to as a thirty-fourth invention) is a wheel based on an output signal from a wheel speed sensor of an electromagnetic pickup type which converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. A wheel speed detecting device for detecting the speed, and a speed difference between the driving wheel and the driven wheel is calculated based on the wheel speed detected by the wheel speed detecting device. If the calculated value exceeds a predetermined value, In a wheel slip control device including a traction control means that performs at least one of control for applying a braking force to a drive wheel and control for reducing an engine output, an output signal from the wheel speed sensor causes a change in an external magnetic field. After it is determined that there is noise due to the wheel speed sensor, a pulse signal corresponding to a speed equal to or higher than a predetermined wheel speed is output from the wheel speed sensor for a certain period of time or more. The time is obtained by such the noise determination is canceled.

Furthermore, the invention according to claim 35 of the present application.
(Hereinafter, referred to as a 35th invention) is a wheel based on an output signal from an electromagnetic pickup type wheel speed sensor which converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. A wheel speed detecting device for detecting the speed, and a speed difference between the driving wheel and the driven wheel is calculated based on the wheel speed detected by the wheel speed detecting device. If the calculated value exceeds a predetermined value, In a wheel slip control device including a traction control unit that performs at least one of a control for applying a braking force to a driving wheel and a control for reducing an engine output, the wheel speed sensor is provided for each of four wheels of a vehicle. After it is installed and it is determined that the output signals from these wheel speed sensors are noises due to changes in the external magnetic field, the wheel speed sensors for all four wheels are set to Upon continued non-pulse state or time is obtained as the noise determination is canceled.

The invention according to claim 36 of the present application (hereinafter referred to as the 36th invention) is the wheel slip sensor according to any one of the 26th to 35th inventions. When it is determined that the output signal from is noise due to the change of the external magnetic field, at least the control for applying the braking force to the driving wheels is prohibited during the noise determination period. is there.

Further, the invention according to claim 37 of the present application (hereinafter referred to as the 37th invention) is an electromagnetic pickup which converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. Wheel speed detection device for detecting the wheel speed based on the output signal from the wheel speed sensor of the formula, and calculates the speed difference between the drive wheel and the driven wheel based on the wheel speed detected by the wheel speed detection device, When the calculated value exceeds a predetermined value, in a wheel slip control device including traction control means for performing at least one of control for applying a braking force to the drive wheels and control for reducing the engine output, If the wheel speed of the drive wheel does not change even after the traction control is performed, the output signal from the wheel speed sensor of the drive wheel is not affected by the change in the external magnetic field. Is determined to be drawing, in the noise determination period is one in which the execution of the traction control is to be prohibited.

[0049]

According to the wheel speed detecting device of the first invention of the present application, when the wheel speed sensor outputs a pulse signal from the non-pulse state, the cycle of the pulse from the start of output to a predetermined number of times. This makes it possible to determine whether or not the output signal is noise due to a change in the external magnetic field. That is, in a normal state without noise, the wheel speed sensor is in a pulseless state (that is, the wheel speed is 0
When outputting a pulse signal from (zero) km / hr) (that is, when detecting the speed at the time of starting the wheel), it is normal for the number of pulses to gradually increase to some extent at first. The number of pulses (that is, the wheel speed) does not suddenly rise to a high value during a predetermined number of times (for example, about a few times) from the start of output, and the pulse cycle during that period becomes considerably long. In other words, the frequency corresponding to that is quite low. Therefore, by setting the frequency in the predetermined range to an appropriate numerical range of height that does not normally occur at the time of rising, it is sure whether the output signal from the wheel speed sensor is noise due to the change of the external magnetic field. Can be determined.

According to the wheel speed detecting device of the second invention of the present application, when the wheel speed sensor outputs a pulse signal from the non-pulse state, the pulse cycle from the start of output to a predetermined number of times causes It is possible to determine whether or not the output signal is noise due to a change in the external magnetic field. That is, in a normal state without noise, the wheel speed sensor is in a pulseless state (that is, the wheel speed is 0 (zero) km / h).
When outputting a pulse signal from (state of r) (that is, when detecting the speed at the time of starting the wheel), it is normal for the number of pulses to gradually increase to some extent at first, and the pulse signal output starts a predetermined number Up to (for example, up to a few times), the pulse number (that is, the wheel speed) does not suddenly rise to a high value, and the pulse period during that period becomes considerably long. In other words, the frequency corresponding to that is quite low. Therefore, by setting the frequency in the predetermined range to an appropriate numerical range of height that does not normally occur at the time of rising, it is sure whether the output signal from the wheel speed sensor is noise due to the change of the external magnetic field. Can be determined. And, in particular, in the case where the wheel speed sensors are attached to each of the four wheels of the vehicle, from the state in which the wheel speed sensors of all four wheels are pulseless, at least one wheel speed sensor is When a pulse signal corresponding to a frequency within a predetermined range of the pulse period from the output start to a predetermined number of times is output, the output signal from each wheel speed sensor is determined to be noise due to a change in the external magnetic field. So
It is possible to make a more rapid noise determination.

Further, according to the wheel speed detecting device of the third aspect of the present invention, when the wheel speed sensor outputs a pulse signal from the non-pulse state, the pulse cycle from the start of output to a predetermined number of times causes It is possible to determine whether or not the output signal is noise due to a change in the external magnetic field. That is, in a normal state without noise, the wheel speed sensor is in a pulseless state (that is, the wheel speed is 0 (zero) km / h).
When outputting a pulse signal from (state of r) (that is, when detecting the speed at the time of starting the wheel), it is normal for the number of pulses to gradually increase to some extent at first, and the pulse signal output starts a predetermined number Up to (for example, up to a few times), the pulse number (that is, the wheel speed) does not suddenly rise to a high value, and the pulse period during that period becomes considerably long. In other words, the frequency corresponding to that is quite low. Therefore, by setting the frequency in the predetermined range to an appropriate numerical range of height that does not normally occur at the time of rising, it is sure whether the output signal from the wheel speed sensor is noise due to the change of the external magnetic field. Can be determined. And, in particular, when the wheel speed sensors are attached to each of the four wheels of the vehicle, the wheel speed sensors of all four wheels are pulseless, and a predetermined number or more (for example, two or more )
For the wheel speed sensor of, when a pulse signal corresponding to a frequency within a predetermined range of the pulse cycle from the output start to a predetermined number of times is output, the output signal from each wheel speed sensor is noise due to a change in the external magnetic field. Since it is determined that there is a noise, more reliable noise determination can be performed.

Further, according to the wheel speed detecting device of the fourth invention of the present application, basically, the same effect as that of any one of the first to third inventions can be obtained. In particular,
If the pulse period from the output start to the predetermined number of times is the normal state without noise, the pulse period becomes the longest (that is, the frequency corresponding to it becomes the lowest). Since the rising and falling cycles are used, more reliable noise determination can be performed.

Further, according to the wheel speed detecting device of the fifth invention of the present application, after the pulse signal of the frequency within the predetermined range is continuously output from the wheel speed sensor for a certain period of time, the non-pulse state is established. It is possible to determine whether or not the output signal is noise due to a change in the external magnetic field, depending on whether or not the non-pulse state continues for a certain amount or more. That is, in a normal state without noise, after the pulse signal of the frequency in the predetermined range is continuously output from the wheel speed sensor for a certain period of time (that is, the rotation speed of the wheel rotating at a constant speed is continuously detected. After that), a pulseless state (that is, a state where the wheel speed is 0 (zero) km / hr) is suddenly established, and this state is not continued. Therefore, if the frequency in the above predetermined range is a normal state without noise,
By setting an appropriate numerical range of the height that does not cause sudden drop in the pulseless state, it is possible to reliably determine whether or not the output signal from the wheel speed sensor is noise due to a change in the external magnetic field. .

Further, according to the wheel speed detecting device of the sixth aspect of the present invention, after the pulse signal of the frequency within the predetermined range is continuously output from the wheel speed sensor for a certain period of time, the non-pulse state is established. It is possible to determine whether or not the output signal is noise due to a change in the external magnetic field, depending on whether or not the non-pulse state continues for a certain amount or more. That is, in a normal state without noise, after the pulse signal of the frequency in the predetermined range is continuously output from the wheel speed sensor for a certain period of time (that is, the rotation speed of the wheel rotating at a constant speed is continuously detected. After that), a pulseless state (that is, a state where the wheel speed is 0 (zero) km / hr) is suddenly established, and this state is not continued. Therefore, if the frequency in the above predetermined range is a normal state without noise,
By setting an appropriate numerical range of the height that does not cause sudden drop in the pulseless state, it is possible to reliably determine whether or not the output signal from the wheel speed sensor is noise due to a change in the external magnetic field. . In particular, when the wheel speed sensor is attached to each of the four wheel speeds of the vehicle, at least one of the four wheel speed sensors has a pulse signal of a frequency within a predetermined range. After being output for a certain period of time,
When the non-pulse state is maintained and the non-pulse state is continued for a predetermined time or longer, the output signal from each wheel speed sensor is determined to be noise due to a change in the external magnetic field, so a more rapid noise determination can be performed. It will be possible to do.

Further, according to the wheel speed detecting device of the seventh invention of the present application, after the pulse signal of the frequency in the predetermined range is continuously output from the wheel speed sensor for a certain period of time, the non-pulse state is established. It is possible to determine whether or not the output signal is noise due to a change in the external magnetic field, depending on whether or not the non-pulse state continues for a certain amount or more. That is, in a normal state without noise, after the pulse signal of the frequency in the predetermined range is continuously output from the wheel speed sensor for a certain period of time (that is, the rotation speed of the wheel rotating at a constant speed is continuously detected. After that), a pulseless state (that is, a state where the wheel speed is 0 (zero) km / hr) is suddenly established, and this state is not continued. Therefore, if the frequency in the above predetermined range is a normal state without noise,
By setting an appropriate numerical range of the height that does not cause sudden drop in the pulseless state, it is possible to reliably determine whether or not the output signal from the wheel speed sensor is noise due to a change in the external magnetic field. . And, in particular, in the case where the wheel speed sensor is attached to each of the four wheel speeds of the vehicle, a predetermined plurality or more (for example, two or more) wheel speed sensors among the wheel speed sensors of these four wheels are: After a pulse signal of a frequency within a predetermined range is continuously output for a certain period of time, it becomes a pulseless state, and when this pulseless state continues for a predetermined period of time or more, the output signal from each wheel speed sensor changes the external magnetic field. Since it is determined that the noise is due to noise, more reliable noise determination can be performed.

Further, according to the wheel speed detecting device of the eighth invention of the present application, basically, the same effect as that of any one of the first to seventh inventions can be obtained.
In particular, since the frequency in the above-mentioned predetermined range is set to 50 to 60 Hz, normally, when a large current of 60 Hz alternating current passes through the Shinkansen used for the drive system, noise due to the change of the external magnetic field accompanying the passage of the Shinkansen is surely ensured. Can be determined. The above-mentioned frequency range of 50 to 60 Hz is due to the fact that a frequency error is expected with respect to 60 Hz which is normally used in Shinkansen.

Further, according to the wheel speed detecting device of the ninth invention of the present application, the wheel speed sensor after it is determined that the output signal from the wheel speed sensor is noise due to the change of the external magnetic field. The noise determination can be canceled according to the output state of the pulse signal from the. That is, when the rotation speed of the wheels is higher than a certain level,
The original signal level output from the wheel speed sensor is high
Since the output is large, even if noise is superimposed, it does not substantially affect the detected value of wheel speed, and when a pulse signal corresponding to such high wheel speed is output for a certain period of time or more, , It is safe to cancel the noise judgment. Therefore, by setting the predetermined wheel speed to an appropriate value of the height at which the corresponding pulse signal is not substantially affected by noise due to changes in the external magnetic field, it is possible to release the accurate noise determination. It can be carried out.

Further, according to the wheel speed detecting device of the tenth invention of the present application, the wheel speed sensor after it is determined that the output signal from the wheel speed sensor is noise due to a change in the external magnetic field. The noise determination can be canceled according to the output state of the pulse signal from the.
That is, when the wheel speed sensor continues to be in the pulseless state for a certain period of time or more, it is considered that there is no noise. In such a case, the noise determination may be canceled. In particular, when the wheel speed sensors are attached to each of the four wheels of the vehicle, and when the wheel speed sensors of all four wheels continue to be in a pulse-free state for a certain period of time or more, the noise determination is performed. Since it is canceled, more accurate noise cancellation can be performed.

Further, according to the wheel slip control device of the eleventh aspect of the present invention, when the wheel speed sensor outputs a pulse signal from the non-pulse state, the pulse cycle from the start of output to a predetermined number of times is determined. It is possible to determine whether or not the output signal is noise due to a change in the external magnetic field. That is, in a normal state without noise, the wheel speed sensor is in a pulseless state (that is, the wheel speed is 0
When outputting a pulse signal from (zero) km / hr) (that is, when detecting the speed at the time of starting the wheel), it is normal for the number of pulses to gradually increase to some extent at first. The number of pulses (that is, the wheel speed) does not suddenly rise to a high value during a predetermined number of times (for example, about a few times) from the start of output, and the pulse cycle during that period becomes considerably long. In other words, the frequency corresponding to that is quite low. Therefore, by setting the frequency in the predetermined range to an appropriate numerical range of height that does not normally occur at the time of rising, it is sure whether the output signal from the wheel speed sensor is noise due to the change of the external magnetic field. Can be determined.

Further, according to the wheel slip control device of the twelfth aspect of the present invention, when the wheel speed sensor outputs a pulse signal from a non-pulse state, the pulse cycle is determined from the start of output to a predetermined number of times. It is possible to determine whether or not the output signal is noise due to a change in the external magnetic field. That is, in a normal state without noise, the wheel speed sensor is in a pulseless state (that is, the wheel speed is 0
When outputting a pulse signal from (zero) km / hr) (that is, when detecting the speed at the time of starting the wheel), it is normal for the number of pulses to gradually increase to some extent at first. The number of pulses (that is, the wheel speed) does not suddenly rise to a high value during a predetermined number of times (for example, about a few times) from the start of output, and the pulse cycle during that period becomes considerably long. In other words, the frequency corresponding to that is quite low. Therefore, by setting the frequency in the predetermined range to an appropriate numerical range of height that does not normally occur at the time of rising, it is sure whether the output signal from the wheel speed sensor is noise due to the change of the external magnetic field. Can be determined. And, in particular, in the case where the wheel speed sensors are attached to each of the four wheels of the vehicle, from the state in which the wheel speed sensors of all four wheels are pulseless, at least one wheel speed sensor is When a pulse signal corresponding to a frequency within a predetermined range of the pulse period from the start of output to a predetermined number of times is output, the output signal from each wheel speed sensor is determined to be noise due to a change in the external magnetic field. As a result, it is possible to make a more rapid noise determination.

Further, according to the wheel slip control device of the thirteenth invention of the present application, when the wheel speed sensor outputs a pulse signal from the non-pulse state, the pulse cycle from the start of output to a predetermined number of times is determined. It is possible to determine whether or not the output signal is noise due to a change in the external magnetic field. That is, in a normal state without noise, the wheel speed sensor is in a pulseless state (that is, the wheel speed is 0
When outputting a pulse signal from (zero) km / hr) (that is, when detecting the speed at the time of starting the wheel), it is normal for the number of pulses to gradually increase to some extent at first. The number of pulses (that is, the wheel speed) does not suddenly rise to a high value during a predetermined number of times (for example, about a few times) from the start of output, and the pulse cycle during that period becomes considerably long. In other words, the frequency corresponding to that is quite low. Therefore, by setting the frequency in the predetermined range to an appropriate numerical range of height that does not normally occur at the time of rising, it is sure whether the output signal from the wheel speed sensor is noise due to the change of the external magnetic field. Can be determined. In particular, when the wheel speed sensors are attached to each of the four wheels of the vehicle, the wheel speed sensors of all of the four wheels are pulseless, and a predetermined number or more (for example, 2
For each wheel speed sensor, when a pulse signal corresponding to a frequency within a predetermined range of the pulse cycle from the output start to a predetermined number of times is output, the output signal from each wheel speed sensor changes the external magnetic field. Since it is determined that the noise is due to noise, more reliable noise determination can be performed.

Furthermore, according to the slip control device for a wheel of the fourteenth invention of the present application, basically, the above-mentioned first slip control device is used.
The same effects as any one of the first to thirteenth inventions can be obtained. In particular, if the pulse cycle from the output start to the predetermined number of times is the normal state without noise, the pulse cycle becomes the longest (that is, the frequency corresponding to it becomes the lowest) from the non-pulse state for the first time. Since the rising and falling cycles of the pulse are used, more reliable noise determination can be performed.

Further, according to the wheel slip control device of the fifteenth invention of the present application, after the pulse signal of the frequency in the predetermined range is continuously output from the wheel speed sensor for a certain period of time, there is no pulse state. Therefore, it is possible to determine whether or not the output signal is noise due to a change in the external magnetic field, depending on whether or not the non-pulse state continues for a certain amount or more. That is, in a normal state without noise, after the pulse signal of the frequency in the predetermined range is continuously output from the wheel speed sensor for a certain period of time (that is, the rotation speed of the wheel rotating at a constant speed is continuously detected. After that, suddenly no pulse (that is, wheel speed 0 (zero) km / hr)
, And this state will not continue. Therefore, if the frequency in the predetermined range is a normal state without noise, the output signal from the wheel speed sensor is set by setting an appropriate numerical range of the height that does not suddenly fall into the pulseless state. It is possible to reliably determine whether or not the noise is due to a change in the external magnetic field.

Furthermore, according to the wheel slip control device of the sixteenth aspect of the present invention, after the pulse signal of the frequency within the predetermined range is continuously output for a certain period of time from the wheel speed sensor, the non-pulse state is obtained. Therefore, it is possible to determine whether or not the output signal is noise due to a change in the external magnetic field, depending on whether or not the non-pulse state continues for a certain amount or more. That is, in a normal state without noise, after the pulse signal of the frequency in the predetermined range is continuously output from the wheel speed sensor for a certain period of time (that is, the rotation speed of the wheel rotating at a constant speed is continuously detected. After that, suddenly no pulse (that is, wheel speed 0 (zero) km / hr)
, And this state will not continue. Therefore, if the frequency in the predetermined range is a normal state without noise, the output signal from the wheel speed sensor is set by setting an appropriate numerical range of the height that does not suddenly fall into the pulseless state. It is possible to reliably determine whether or not the noise is due to a change in the external magnetic field. And, in particular,
In the case where the wheel speed sensor is attached to each of the four wheel speeds of the vehicle, a pulse signal of a frequency in a predetermined range continues for a certain period of time for at least one wheel speed sensor of the four wheel speed sensors. The output signal from each of the wheel speed sensors is determined to be noise due to a change in the external magnetic field when the pulseless state is maintained for a predetermined time or longer after being output. It is possible to make a more rapid noise determination.

Furthermore, according to the wheel slip control device of the seventeenth aspect of the present invention, after the pulse signal of the frequency within the predetermined range is continuously output for a certain period of time from the wheel speed sensor, the no-pulse state is obtained. Therefore, it is possible to determine whether or not the output signal is noise due to a change in the external magnetic field, depending on whether or not the non-pulse state continues for a certain amount or more. That is, in a normal state without noise, after the pulse signal of the frequency in the predetermined range is continuously output from the wheel speed sensor for a certain period of time (that is, the rotation speed of the wheel rotating at a constant speed is continuously detected. After that, suddenly no pulse (that is, wheel speed 0 (zero) km / hr)
, And this state will not continue. Therefore, if the frequency in the predetermined range is a normal state without noise, the output signal from the wheel speed sensor is set by setting an appropriate numerical range of the height that does not suddenly fall into the pulseless state. It is possible to reliably determine whether or not the noise is due to a change in the external magnetic field. And, in particular,
When the wheel speed sensor is attached to each of the four wheel speeds of the vehicle, a predetermined range or more (for example, two or more) of the wheel speed sensors of the four wheel speed sensors has a frequency within a predetermined range. After the pulse signal of is continuously output for a certain period of time, it becomes a pulseless state, and when this pulseless state is continued for a predetermined time or longer, the output signal from each wheel speed sensor is noise due to a change of the external magnetic field. Since it is determined that the noise is determined, more reliable noise determination can be performed.

Furthermore, according to the slip control device for a wheel of the eighteenth invention of the present application, basically, the first slip control device described above is used.
The same effects as any one of the first to seventeenth inventions can be obtained. In particular, the frequency in the above predetermined range is set to 50 to 60.
Since it is set to Hz, normally, when a large current of 60 Hz alternating current passes through the vicinity of a vehicle of the Shinkansen used for the drive system, noise due to a change in the external magnetic field due to the passage of the Shinkansen can be reliably identified. The frequency range above 50
60Hz is the 60 that is normally used in Shinkansen
This is due to the fact that a frequency error is taken into account with respect to Hz.

Furthermore, according to the wheel slip control device of the nineteenth invention of the present application, the wheel speed after the output signal from the wheel speed sensor is determined to be noise due to a change in the external magnetic field. The noise determination can be canceled according to the output state of the pulse signal from the sensor. That is, when the rotation speed of the wheel is higher than a certain level, the original signal level output from the wheel speed sensor is high (the output is large), so even if noise is superimposed, the detected value of the wheel speed is substantially reduced. There is no problem even if the noise determination is canceled when the pulse signal corresponding to such a high wheel speed is output for a certain time or more without any influence. Therefore, by setting the predetermined wheel speed to an appropriate value of the height at which the corresponding pulse signal is not substantially affected by noise due to changes in the external magnetic field, it is possible to release the accurate noise determination. It can be carried out.

Furthermore, according to the wheel slip control device of the twentieth aspect of the present invention, the wheel speed after the output signal from the wheel speed sensor is determined to be noise due to a change in the external magnetic field. The noise determination can be canceled according to the output state of the pulse signal from the sensor. That is, when the wheel speed sensor continues to be in the pulseless state for a certain period of time or more, it is considered that there is no noise. In such a case, the noise determination may be canceled. In particular, when the wheel speed sensors are attached to each of the four wheels of the vehicle, and when the wheel speed sensors of all four wheels continue to be in a pulse-free state for a certain period of time or more, the noise determination is performed. Since it is canceled, more accurate noise cancellation can be performed.

According to the slip control device for a wheel of the twenty-first invention of the present application, basically, the same effect as that of any one of the above-mentioned eleventh to twentieth inventions can be obtained. Moreover, when estimating the pseudo vehicle body speed of the vehicle based on the wheel speed detected by the wheel speed detection device, it is determined that the output signal from the wheel speed sensor is noise due to a change in the external magnetic field. If
Since the increase in the estimated value of the pseudo vehicle body speed is limited during the noise determination period, the pseudo vehicle body speed that is generally given by the highest value among the four wheel speeds during the noise determination period is It is possible to prevent the value from becoming higher than the actual value due to the influence of noise, and it is possible to prevent the anti-skid control from being executed in an unexpected driving state of the driver. That is, it is possible to avoid the influence of noise due to a change in the external magnetic field without causing a large increase in cost as in the case of changing the number of teeth of the tooth profile rotor of the wheel speed detecting device.

Furthermore, according to the slip control device for a wheel of the twenty-second invention of the present application, basically the same effect as that of any one of the above-mentioned eleventh to twentieth inventions can be obtained. Moreover, when estimating the pseudo vehicle body speed of the vehicle based on the wheel speed detected by the wheel speed detection device, it is determined that the output signal from the wheel speed sensor is noise due to a change in the external magnetic field. If
During the noise determination period, the pseudo vehicle body speed is estimated to be 0 km / hr. Therefore, during the noise determination period, the pseudo vehicle body speed generally given by the highest value among the four wheel speeds is It is possible to reliably prevent the value higher than the actual value due to the influence of noise, and it is possible to prevent the anti-skid control from being executed in an unexpected driving state of the driver. That is, it is possible to reliably avoid the influence of noise due to a change in the external magnetic field without causing a large increase in cost as in the case of changing the number of teeth of the tooth profile rotor of the wheel speed detecting device.

Further, according to the slip control device for a wheel of the twenty-third invention of the present application, basically, the first slip control device described above is used.
The same effect as any one of the first to twentieth inventions can be obtained. Moreover, when the output signal from the wheel speed sensor is determined to be noise due to a change in the external magnetic field, the wheel speed for performing the anti-skid control is changed during the noise determination period. Since the minimum value is increased by the predetermined amount, it is difficult to enter the antiskid control during the noise determination period, and it is possible to prevent the antiskid control from being executed in an unexpected driving state of the driver. That is, it is possible to avoid the influence of noise due to a change in the external magnetic field without causing a large increase in cost as in the case of changing the number of teeth of the tooth profile rotor of the wheel speed detecting device.

Further, according to the slip control device for a wheel of the twenty-fourth invention of the present application, basically, the first slip control device described above is used.
The same effect as any one of the first to twentieth inventions can be obtained. Moreover, when the output signal from the wheel speed sensor is determined to be noise due to a change in the external magnetic field, the control threshold for starting the anti-skid control during the noise determination period. Is changed to the side where it is hard to enter the control, so that it is difficult to enter the antiskid control during the noise determination period, and it is possible to prevent the driver from executing the antiskid control in an unexpected driving state. That is, it is possible to avoid the influence of noise due to a change in the external magnetic field without causing a large increase in cost as in the case of changing the number of teeth of the tooth profile rotor of the wheel speed detecting device.

Further, according to the slip control device for a wheel of the twenty-fifth invention of the present application, basically, the first slip control device described above is used.
The same effect as any one of the first to twentieth inventions can be obtained. Moreover, when the output signal from the wheel speed sensor is determined to be noise due to a change in the external magnetic field, the start of the anti-skid control is prohibited during the noise determination period. So
During the noise determination period, it is possible to prevent the antiskid control from being executed in an unexpected driving state of the driver. That is, it is possible to reliably avoid the influence of noise due to a change in the external magnetic field without causing a large increase in cost as in the case of changing the number of teeth of the tooth profile rotor of the wheel speed detecting device.

Further, according to the wheel slip control device of the twenty-sixth aspect of the present invention, when the wheel speed sensor outputs a pulse signal from the non-pulse state, the pulse cycle from the output start to a predetermined number of times It is possible to determine whether or not the output signal is noise due to a change in the external magnetic field. That is, in a normal state without noise, the wheel speed sensor is in a pulseless state (that is, the wheel speed is 0
When outputting a pulse signal from (zero) km / hr) (that is, when detecting the speed at the time of starting the wheel), it is normal for the number of pulses to gradually increase to some extent at first. The number of pulses (that is, the wheel speed) does not suddenly rise to a high value during a predetermined number of times (for example, about a few times) from the start of output, and the pulse cycle during that period becomes considerably long. In other words, the frequency corresponding to that is quite low. Therefore, by setting the frequency in the predetermined range to an appropriate numerical range of height that does not normally occur at the time of rising, it is sure whether the output signal from the wheel speed sensor is noise due to the change of the external magnetic field. Can be determined.

Furthermore, according to the wheel slip control device of the twenty-seventh aspect of the present invention, when the wheel speed sensor outputs a pulse signal from the non-pulse state, the pulse cycle from the start of output to a predetermined number of times is determined. It is possible to determine whether or not the output signal is noise due to a change in the external magnetic field. That is, in a normal state without noise, the wheel speed sensor is in a pulseless state (that is, the wheel speed is 0
When outputting a pulse signal from (zero) km / hr) (that is, when detecting the speed at the time of starting the wheel), it is normal for the number of pulses to gradually increase to some extent at first. The number of pulses (that is, the wheel speed) does not suddenly rise to a high value during a predetermined number of times (for example, about a few times) from the start of output, and the pulse cycle during that period becomes considerably long. In other words, the frequency corresponding to that is quite low. Therefore, by setting the frequency in the predetermined range to an appropriate numerical range of height that does not normally occur at the time of rising, it is sure whether the output signal from the wheel speed sensor is noise due to the change of the external magnetic field. Can be determined. And, in particular, in the case where the wheel speed sensors are attached to each of the four wheels of the vehicle, from the state in which the wheel speed sensors of all four wheels are pulseless, at least one wheel speed sensor is When a pulse signal corresponding to a frequency within a predetermined range of the pulse period from the start of output to a predetermined number of times is output, the output signal from each wheel speed sensor is determined to be noise due to a change in the external magnetic field. As a result, it is possible to make a more rapid noise determination.

Further, according to the slip control device for a wheel of the twenty-eighth invention of the present application, when the above-mentioned wheel speed sensor outputs a pulse signal from a non-pulse state, the pulse cycle from the output start to a predetermined number of times is determined. It is possible to determine whether or not the output signal is noise due to a change in the external magnetic field. That is, in a normal state without noise, the wheel speed sensor is in a pulseless state (that is, the wheel speed is 0
When outputting a pulse signal from (zero) km / hr) (that is, when detecting the speed at the time of starting the wheel), it is normal for the number of pulses to gradually increase to some extent at first. The number of pulses (that is, the wheel speed) does not suddenly rise to a high value during a predetermined number of times (for example, about a few times) from the start of output, and the pulse cycle during that period becomes considerably long. In other words, the frequency corresponding to that is quite low. Therefore, by setting the frequency in the predetermined range to an appropriate numerical range of height that does not normally occur at the time of rising, it is sure whether the output signal from the wheel speed sensor is noise due to the change of the external magnetic field. Can be determined. In particular, when the wheel speed sensors are attached to each of the four wheels of the vehicle, the wheel speed sensors of all of the four wheels are pulseless, and a predetermined number or more (for example, 2
For each wheel speed sensor, when a pulse signal corresponding to a frequency within a predetermined range of the pulse cycle from the output start to a predetermined number of times is output, the output signal from each wheel speed sensor changes the external magnetic field. Since it is determined that the noise is due to noise, more reliable noise determination can be performed.

Further, according to the slip control device for a wheel of the twenty-ninth invention of the present application, basically, the above-mentioned second slip control device is used.
The same effect as that of any one of the sixth to twenty-eighth aspects can be obtained. In particular, if the pulse cycle from the output start to the predetermined number of times is the normal state without noise, the pulse cycle becomes the longest (that is, the frequency corresponding to it becomes the lowest) from the non-pulse state for the first time. Since the rising and falling cycles of the pulse are used, more reliable noise determination can be performed.

Further, according to the slip control device for a wheel of the thirtieth invention of the present application, a pulse signal having a frequency within a predetermined range is continuously output for a certain period of time from the wheel speed sensor, and then a non-pulse state is obtained. Therefore, it is possible to determine whether or not the output signal is noise due to a change in the external magnetic field, depending on whether or not the non-pulse state continues for a certain amount or more. That is, in a normal state without noise, after the pulse signal of the frequency in the predetermined range is continuously output from the wheel speed sensor for a certain period of time (that is, the rotation speed of the wheel rotating at a constant speed is continuously detected. After that, suddenly no pulse (that is, wheel speed 0 (zero) km / hr)
, And this state will not continue. Therefore, if the frequency in the predetermined range is a normal state without noise, the output signal from the wheel speed sensor is set by setting an appropriate numerical range of the height that does not suddenly fall into the pulseless state. It is possible to reliably determine whether or not the noise is due to a change in the external magnetic field.

Further, according to the slip control device for a wheel of the thirty-first invention of the present application, after the pulse signal of the frequency within the predetermined range is continuously output from the wheel speed sensor for a certain period of time, there is no pulse state. Therefore, it is possible to determine whether or not the output signal is noise due to a change in the external magnetic field, depending on whether or not the non-pulse state continues for a certain amount or more. That is, in a normal state without noise, after the pulse signal of the frequency in the predetermined range is continuously output from the wheel speed sensor for a certain period of time (that is, the rotation speed of the wheel rotating at a constant speed is continuously detected. After that, suddenly no pulse (that is, wheel speed 0 (zero) km / hr)
, And this state will not continue. Therefore, if the frequency in the predetermined range is a normal state without noise, the output signal from the wheel speed sensor is set by setting an appropriate numerical range of the height that does not suddenly fall into the pulseless state. It is possible to reliably determine whether or not the noise is due to a change in the external magnetic field. And, in particular,
In the case where the wheel speed sensor is attached to each of the four wheel speeds of the vehicle, a pulse signal of a frequency in a predetermined range continues for a certain period of time for at least one wheel speed sensor of the four wheel speed sensors. The output signal from each of the wheel speed sensors is determined to be noise due to a change in the external magnetic field when the pulseless state is maintained for a predetermined time or longer after being output. It is possible to make a more rapid noise determination.

Further, according to the slip control device for a wheel of the thirty-second invention of the present application, a pulse signal having a frequency within a predetermined range is continuously output from the wheel speed sensor for a certain period of time, and then a non-pulse state is obtained. Therefore, it is possible to determine whether or not the output signal is noise due to a change in the external magnetic field, depending on whether or not the non-pulse state continues for a certain amount or more. That is, in a normal state without noise, after the pulse signal of the frequency in the predetermined range is continuously output from the wheel speed sensor for a certain period of time (that is, the rotation speed of the wheel rotating at a constant speed is continuously detected. After that, suddenly no pulse (that is, wheel speed 0 (zero) km / hr)
, And this state will not continue. Therefore, if the frequency in the predetermined range is a normal state without noise, the output signal from the wheel speed sensor is set by setting an appropriate numerical range of the height that does not suddenly fall into the pulseless state. It is possible to reliably determine whether or not the noise is due to a change in the external magnetic field. And, in particular,
When the wheel speed sensor is attached to each of the four wheel speeds of the vehicle, a predetermined range or more (for example, two or more) of the wheel speed sensors of the four wheel speeds falls within a predetermined range. After the pulse signal of is continuously output for a certain period of time, it becomes a pulseless state, and when this pulseless state is continued for a predetermined time or longer, the output signal from each wheel speed sensor is noise due to a change of the external magnetic field. Since it is determined that the noise is determined, more reliable noise determination can be performed.

Further, according to the slip control device for a wheel of the thirty-third invention of the present application, basically, the second slip control device described above is used.
The same effects as any one of the sixth to thirty-second inventions can be obtained. In particular, the frequency in the above predetermined range is set to 50 to 60.
Since it is set to Hz, normally, when a high current of 60 Hz alternating current passes near the Shinkansen vehicle used for the drive system, noise due to a change in the external magnetic field due to the passage of the Shinkansen can be reliably identified. In addition, the frequency range is 50 to 6
0Hz is 60Hz which is usually used in Shinkansen
On the other hand, it is due to the fact that a frequency error is expected.

Furthermore, according to the slip control device for a wheel of the thirty-fourth invention of the present application, the wheel speed after the output signal from the wheel speed sensor is determined to be noise due to a change in the external magnetic field. The noise determination can be canceled according to the output state of the pulse signal from the sensor. That is, when the rotation speed of the wheel is higher than a certain level, the original signal level output from the wheel speed sensor is high (the output is large), so even if noise is superimposed, the detected value of the wheel speed is substantially reduced. There is no problem even if the noise determination is canceled when the pulse signal corresponding to such a high wheel speed is output for a certain time or more without any influence. Therefore, by setting the predetermined wheel speed to an appropriate value of the height at which the corresponding pulse signal is not substantially affected by noise due to changes in the external magnetic field, it is possible to release the accurate noise determination. It can be carried out.

Furthermore, according to the wheel slip control device of the thirty-fifth aspect of the present invention, the wheel speed after the output signal from the wheel speed sensor is determined to be noise due to a change in the external magnetic field. The noise determination can be canceled according to the output state of the pulse signal from the sensor. That is, when the wheel speed sensor continues to be in the pulseless state for a certain period of time or more, it is considered that there is no noise. In such a case, the noise determination may be canceled. In particular, when the wheel speed sensors are attached to each of the four wheels of the vehicle, and when the wheel speed sensors of all four wheels continue to be in a pulse-free state for a certain period of time or more, the noise determination is performed. Since it is canceled, more accurate noise cancellation can be performed.

According to the slip control device for a wheel of the thirty-sixth invention of the present application, basically, the same effect as that of any one of the twenty-sixth to thirty-fifth inventions can be obtained. Moreover, when it is determined that the output signal from the wheel speed sensor is noise due to the change in the external magnetic field, at least the control for applying the braking force to the driving wheels is performed during the noise determination period. Since the prohibition is performed, it is possible to prevent the driving wheels from being braked by the traction control in an unexpected driving state during the noise determination period. That is, it is possible to reliably avoid the influence of noise due to a change in the external magnetic field without causing a large increase in cost as in the case of changing the number of teeth of the tooth profile rotor of the wheel speed detecting device.

Further, according to the slip control device of the thirty-seventh aspect of the present invention, when the wheel speed of the drive wheels does not change even after the traction control is performed, the output from the wheel speed sensor of the drive wheels is output. The signal is determined to be noise due to changes in the external magnetic field, and during this noise determination period, the execution of the traction control is prohibited.Therefore, during the noise determination period, the driver is in an unexpected driving state. It is possible to prevent the driving wheels from being braked by the traction control. That is, as in the case of changing the number of teeth of the tooth profile rotor of the wheel speed detection device,
It is possible to reliably avoid the influence of noise due to changes in the external magnetic field without causing a large increase in cost.

[0086]

Embodiments of the present invention will be described below as a so-called anti-skid control device (hereinafter referred to as AB
A case where the present invention is applied to a wheel speed detection device and an ABS control device mounted on an automobile equipped with an S control device) will be described with reference to the accompanying drawings. Figure 1
[FIG. 3] is a plan view schematically showing an overall configuration of a vehicle braking system of an automobile according to the present embodiment. As shown in this figure, in the above vehicle, the left and right front wheels 1 and 2 are driven wheels, and the left and right rear wheels 3 and
4 is a rear-wheel drive type drive wheel, and the output torque of the engine 5 is from the automatic transmission 6 through the propeller shaft 7, the differential device 8 and the left and right drive shafts 9 and 10
It is adapted to be transmitted to the left and right rear wheels 3 and 4. The front wheels 1 and 2 and the rear wheels 3 and 4 have disks 11a to 14a that rotate integrally with the wheels 1 to 4 and a caliper 11b that receives the supply of braking pressure to brake the rotation of the disks 11a to 14a. .., 14b, etc. are provided respectively, and these braking devices 11-14 are operated by a brake control system described below.

The above-described vehicle brake control system includes a booster device 17 for increasing the depression force of the brake pedal 16 by the driver, and a master cylinder for generating a braking pressure according to the depression force increased by the booster device 17. 18
It has and. The front wheel braking pressure supply line 19 led from the master cylinder 18 is branched into two paths, and the left and right front wheel branch braking pressure lines 19a and 19b respectively provided in these branches are provided in the left and right front wheels 1 and 2. The brake devices 11 and 12 are connected to the calipers 11b and 12b, respectively. The left front wheel branch braking pressure line 19a leading to the brake device 11 for the left front wheel 1 is provided with an electromagnetic opening / closing valve 20a and an electromagnetic relief valve 20b.
A valve unit 20 is installed. Also, the right front wheel 2
In the same way as the first valve unit 20, a second valve unit 21 having an electromagnetic opening / closing valve 21a and an electromagnetic relief valve 21b is also installed in the right front wheel branch braking pressure line 19b leading to the brake device 12 of FIG. Has been done.

On the other hand, the rear wheel braking pressure supply line 22 led from the master cylinder 18 is connected to the first and second brake wheels.
Electromagnetic on-off valve 23a similar to valve units 20 and 21
A third valve unit 23 including an electromagnetic relief valve 23b and an electromagnetic relief valve 23b is installed. The rear wheel braking pressure supply line 22 is branched into two paths downstream of the third valve unit 23. The left and right rear wheel branch braking pressure lines 22a and 22b, which are respectively provided by branching the left and right rear wheels 3,
Calipers 13b, 1 of the braking devices 13, 14 in FIG.
4b are connected respectively. That is, in the brake control system in the present embodiment, the brake device 1 for the left front wheel 1 is operated by the operation of the first valve unit 20.
A first channel for variably controlling the braking pressure of No. 1 and a second channel for variably controlling the braking pressure of the braking device 12 at the right front wheel 2 by the operation of the second valve unit 21;
By the operation of the third valve unit 23, the left and right rear wheels 3,
4 and a third channel for variably controlling the braking pressure of both brake devices 13, 14 are provided.
The channels are controlled independently of each other.

The brake control system is provided with an electronically controlled control unit (hereinafter referred to as ECU) 24 for controlling the first to third channels, respectively. This ECU 24 uses the brake pedal 16
The brake signal from the brake switch 25 that detects ON / OFF of the wheel and the wheel speed signals from the wheel speed sensors 26 to 29 that detect the rotation speeds of the respective wheels are input,
By outputting braking pressure control signals corresponding to these signals to the first to third valve units 20, 21, 23, respectively, braking control for slippage of the left and right front wheels 1, 2 and rear wheels 3, 4, that is, ABS The control is performed in parallel for each of the first to third channels. In the present embodiment, as the wheel speed sensors 26 to 29, so-called detailed description will be given later, so-called so-called conversion of a magnetic flux change into a voltage signal and outputting a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. An electromagnetic pickup type is used, and a wheel speed detecting device for detecting the wheel speeds of the wheels 1 to 4 based on the output signals from the wheel speed sensors 26 to 29 is provided.

The ECU 24 uses the wheel speed sensors 2
Based on the wheel speeds indicated by the wheel speed signals from 6 to 29, the on-off valves 20a, 21a, 23a and the relief valves 20b, 21b, 23b in the first to third valve units 20, 21, 23 are controlled by duty control. By controlling the opening / closing, the braking force is applied to the front wheels 1 and 2 and the rear wheels 3 and 4 with the braking pressure according to the slip state of each wheel 1 to 4. In addition, the first to third valve units 20, 21, 2
The brake oil discharged from the relief valves 20b, 21b, 23b in No. 3 is returned to the reservoir tank 18a of the master cylinder 18 via a drain line (not shown).

In the ABS non-control state, no braking pressure control signal is output from the ECU 24. Therefore, as shown in FIG.
~ Relief valves 20b, 21b, 23b of the third valve units 20, 21, 23 are closed and held, and the opening / closing valves 20a, 21a, 23 of the valve units 20, 21, 23 are closed.
Each a will be held open. That is, the braking pressure generated in the master cylinder 18 according to the stepping force of the brake pedal 16 is passed through the front wheel braking pressure supply line 19 and the rear wheel braking pressure supply line 22 to the left and right front wheels 1, 2 and the rear wheels 3. , 4 are supplied to the brake devices 11 to 14, and the braking force corresponding to these braking pressures is applied to the front wheels 1 and 2.
Also, it is directly applied to the rear wheels 3 and 4.

Next, an outline of the brake control performed by the ECU 24 will be described. That is, the ECU 24 calculates the acceleration and deceleration for each wheel based on the wheel speeds indicated by the signals from the wheel speed sensors 26 to 29. Here, the calculation method of the acceleration or deceleration will be explained.
The CU 24 divides the difference between the previous value of the wheel speed and the previous value by the predetermined sampling period Δt (for example, 7 ms), and then updates the value obtained by converting the result to the gravitational acceleration as the current acceleration or deceleration. Then, the ECU 24
The rear wheels 3 and 4 representing the wheel speed and acceleration / deceleration for the third channel are selected. In the present embodiment, more preferably, both wheel speeds W3 and W4 are taken into consideration in consideration of the detection error of the both wheel speed sensors 28 and 29 of the rear wheels 3 and 4 at the time of slip.
The smaller one of the wheel speeds is selected as the rear wheel speed Wr, and the acceleration and deceleration obtained from this wheel speed Wr are used as the rear wheel deceleration and the rear wheel acceleration.

Further, the ECU 24 estimates the pseudo vehicle body speed Vr and the road surface friction coefficient of the vehicle. Of these, the pseudo vehicle body speed Vr is specifically obtained as follows. That is, the ECU 24 selects the highest wheel speed Wmx from the wheel speeds W1 to W4 indicated by the signals from the wheel speed sensors 26 to 29.
Then, the maximum wheel speed Wmx is set to the pseudo vehicle speed Vr.
To be adopted as. At that time, when the wheel speeds W3 and W4 indicated by the signals from the wheel speed sensors 28 and 29 provided on the rear wheels 3 and 4 which are the driving wheels are used as the maximum wheel speed Wmx, the rear wheels 3 and 4 are used. The wheel speeds W3, W2 are higher than the wheel speeds W1, W2 indicated by signals from the wheel speed sensors 26, 27 provided on the front wheels 1, 2 which are the driven wheels due to slipping of
When W4 shows a large value, one of the wheel speeds W1, W2 of the front wheels 1, 2 is adopted as the pseudo vehicle body speed Vr.

On the other hand, when all of the front wheels 1 and 2 and the rear wheels 3 and 4 are locked, as shown in the following Table 1, a table preset corresponding to the friction coefficient value MU is referred to,
Assuming a change amount (hereinafter, referred to as a vehicle body speed change amount) ΔVr of the pseudo vehicle body speed Vr per unit time at that time, the pseudo vehicle body speed Vr is decreased according to the vehicle body speed change amount ΔVr.

[0095]

[Table 1]

That is, as will be described later, when the friction coefficient value MU indicating the road surface friction coefficient estimated based on the pseudo vehicle speed Vr is set to 1 indicating a low μ road surface, the vehicle speed change amount ΔVr changes. Low-0.3G (value converted to gravitational acceleration) is selected, while the above friction coefficient value MU
Is set to 3 indicating a high μ road surface, -1.2G, which has a large amount of change in vehicle speed change ΔVr, is selected. When the friction coefficient value MU is set to 2 which is an intermediate state between the high μ road surface and the low μ road surface, the vehicle speed change amount ΔVr is set to −0.8 G which is an intermediate value between the two.
Is selected. In this way, the pseudo vehicle body speed Vr of the vehicle is sampled in accordance with the wheel speeds W1 to W4.
It will be updated every time. In the present embodiment, as will be described later in detail, when estimating the pseudo vehicle body speed Vr,
When it is determined that the output signals from the wheel speed sensors 26 to 29 are noise due to a change in the external magnetic field, the increase in the estimated value Vr of the pseudo vehicle body speed is limited during the noise determination period. It is like this.

On the other hand, the road surface friction coefficient is specifically determined as follows. That is, the ECU 24 calculates the vehicle body speed change amount ΔVr from the pseudo vehicle body speed Vr estimated as described above, and, as shown in Table 2 below, indicates the friction coefficient value set in advance according to the vehicle body speed change amount. The above-mentioned vehicle speed change amount ΔVr is applied to the table and a corresponding value is set as the friction coefficient value MU.

[0098]

[Table 2]

Here, the table of the friction coefficient value MU is set in three stages according to the vehicle body speed change amount ΔVr. For example, the vehicle body speed change amount ΔVr converted into gravitational acceleration is -0.3G. Also has a large value, that is, when the change is small, the friction coefficient value MU indicates a low μ road surface 1
Is selected. On the other hand, when the vehicle body speed change amount ΔVr is a value smaller than -1.2 G, that is, when the change is large,
As the friction coefficient value MU, 3 indicating a high μ road surface is selected.
When the vehicle body speed change amount ΔVr indicates an intermediate value between the two values, 2 indicating a medium friction road surface is selected as the friction coefficient value MU.

The ECU 24 uses the wheel speed sensors 28, 2
The first to third wheel speeds Wr and W2 of the left and right front wheels 1 and 2 and the pseudo vehicle body speed Vr indicated by the signals from the wheel speed sensors 26 and 27, respectively. The slip rate for each channel is calculated. At that time, the slip rate is calculated using the following relational expression. Slip rate = (wheel speed / pseudo vehicle speed) × 100 In other words, as the deviation of the wheel speed from the pseudo vehicle speed increases, the slip rate decreases, and the slip tendency of the wheel increases. Subsequently, the ECU 24 executes the above first to third
Set various control thresholds used for channel control.

Here, the outline of the control threshold setting process will be described. This control threshold setting process is performed as follows for the first channel, for example. That is, the ECU 24 selects a control threshold value corresponding to the friction coefficient value and the pseudo vehicle body speed from various control threshold values set in advance according to the vehicle speed range and the road surface friction coefficient. As these control threshold values, for example, the 0-2 deceleration threshold value B02 for determining the transition from the phase 0 indicating the ABS non-control state to the phase 2 indicating the holding state after the pressure increase, and the phase 1 indicating the pressure increase state from the above 1-2 deceleration threshold B for determination of transition to phase 2
12, 2-3 deceleration threshold value B23 for determination of transition from phase 2 to phase 3 indicating depressurized state, 3-5 deceleration for transition determination from phase 3 to phase 5 indicating retained state after depressurization Threshold value B35, 5-1 slip rate threshold value Bsz for judging pressure increase from phase 5 to phase 1, and initial slip rate threshold value B for the first cycle immediately after control start
i and the like are set in accordance with the vehicle speed range and the road surface friction coefficient.

In this case, the deceleration threshold value that greatly affects the braking force is the braking performance when the road surface friction coefficient is large,
In order to achieve a high level of control responsiveness when the road surface friction coefficient is small, it is more preferably set to approach 0G as the level of the friction coefficient value becomes smaller, that is, as the road surface friction coefficient becomes smaller. Further, control thresholds are similarly set for the second and third channels. Then, the ECU 24 performs the lock determination process for each channel and the first to third valve units 2 described above.
Phase determination processing for defining the control amount for 0, 21, and 23 is performed.

The lock determination process will be described below. For example, in the lock determination process for the first channel for the left front wheel,
The ECU 24 first determines the continuation flag Fc for the first channel.
The current value of is set as the previous value, and then the pseudo vehicle body speed Vr and the wheel speed W1 are set under predetermined conditions (for example, Vr <5 km
/ H, W1 <7.5 km / h) is determined, and when these conditions are satisfied, the continuation flag Fc and the lock flag Fl1 are reset to 0, respectively, and if they are not satisfied, the log flag It is determined whether or not Fl1 is set to 1. If the lock flag Fl1 is not set to 1, the lock flag F is set under a predetermined condition (for example, when the pseudo vehicle body speed Vr is higher than the wheel speed W1).
Set 1 to l1. On the other hand, when the ECU 24 determines that the lock flag Fl1 is set to 1, for example, when the phase value P1 of the first channel is set to 5 indicating phase 5, and the slip ratio S1 is larger than 90%, for example. The continuation flag Fc is set to 1. The lock determination process is similarly performed for the second and third channels.

Further, to explain the outline of the phase determination processing, the ECU 24 compares the control threshold values set according to the operating state of the vehicle with the wheel acceleration / deceleration and the slip ratio to determine the ABS non-control state. Phase 0 shown, Phase 1 showing the pressure increasing state during ABS control, Phase 2 showing the holding state after pressure increasing, Phase 3 showing the pressure reducing state, Phase 4 showing the rapid pressure reducing state, and Phase showing the holding state after pressure reducing 5 is selected. Then, the ECU 24 sets a control amount according to the phase value set for each channel, and then sends a braking pressure control signal according to the control amount to the first to third valve units 2.
It outputs to 0, 21, and 23, respectively. This allows
The braking pressures of the front wheel branch braking pressure lines 19a, 19b and the rear wheel branch braking pressure lines 22a, 22b on the downstream side of the first to third valve units 20, 21, 23 are increased or decreased, or increased. Or, it is kept at the pressure level after decompression.

The control process of the braking pressure in the brake control system is performed as follows according to the flow chart of FIG. 2, taking the first channel as an example. That is, the ECU 24 executes step S1.
At step S2, various data are fetched, and then step S2 is executed to judge whether or not the value of the ABS flag Fa is set to 1. That is, it is determined whether or not ABS control is in progress. The ABS flag Fa is set to 1 when any one of the lock flags Fl1, Fl2, Fl3 of the first to third channels is set to 1, and the brake switch 25 is switched from ON to OFF. It is a flag that is cleared to 0 when it is hit. ECU
24 indicates that the ABS flag Fa is 1 in step S2.
If it is determined to be set to step S3,
Then, it is determined whether the road surface friction coefficient is high μ or not. In this embodiment, it is determined to be YES when the friction coefficient value MU is set to 3 indicating the high μ road surface, and is determined to be NO when the friction coefficient value MU is set to 2 or 1 other than that. Has become.

When the ECU 24 determines in step S3 that the road surface friction coefficient is not high μ, step S4 is executed and the wheel speed W1 of the left front wheel 1 indicated by the signal from the wheel speed sensor 26 is the first set value V1. (Eg 3.5k
m / h), and when it is determined that the wheel speed W1 is greater than the first set value V1, the process proceeds to step S5, where it is determined whether the ABS control is completed. When it is determined that the control is not completed, step S6 is executed and the normal ABS control is executed according to a predetermined subroutine. On the other hand, when the ECU 24 determines in step S4 that the wheel speed W1 is not greater than the first set value V1, the ECU 24 proceeds to step S7, sets a predetermined slow pressure increase control amount, and then executes step S8. Then, the lock flag Fl1 and the continuation flag Fc are each cleared to 0.

If the ECU 24 determines in step S3 that the road surface friction coefficient is high μ,
In step S9, the wheel speed W1 is the first set value V1.
It is determined whether or not the wheel speed W1 is higher than the second set value V2 (for example, 5 km / h) set on the higher wheel speed side. In this case as well, if the wheel speed W1 is larger than the second set value V2. If it is determined, the process proceeds to step S5 to determine whether or not the ABS control is completed. If it is determined that the ABS control is not completed, step S6 is executed and the normal ABS control is executed according to a predetermined subroutine. It is like this. On the other hand, when the ECU 24 determines in step S9 that the wheel speed W1 is not greater than the second set value V2, the ECU 24 executes step S10 to set a predetermined normal pressure increase control amount, and in this case as well. Step S8 is executed to execute the lock flag Fl1 and the continuation flag Fc.
To 0 respectively.

Next, the ABS control in the brake control system will be described by taking the case of the first channel as an example. That is, in the ABS non-controlled state during deceleration, the braking pressure generated in the master cylinder 18 is gradually increased by the depression operation of the brake pedal 16, and, for example, as shown in FIG. 3 (d), the wheel speed W1 of the left front wheel 1 is increased. When the amount of change in (i.e., the wheel deceleration DW1) reaches -3G, the lock flag Fl1 in the first channel is set to 1 and simultaneously the ABS flag Fa is set, as shown in FIGS. Is also set to 1, and from that point A
It will shift to BS control.

Then, the ECU 24 determines the slip ratio S1, the deceleration DW1, and the acceleration AW calculated from the wheel speed W1.
1 and the above-mentioned various control threshold values are compared. In this case, assuming that the initial slip ratio threshold B1 is set to, for example, 90%, when the slip ratio S1 indicates, for example, 96%, the ECU 24 indicates the phase value P as shown in FIG.
Change 1 from 0 to 2. Therefore, the braking pressure is
As shown in (f), it will be maintained at the level immediately after the pressure increase. Thereafter, for example, when the slip ratio S1 falls below 90%, the ECU 24 sets the phase value P1 to 2
Change from 3 to 3. As a result, the first valve unit 2
The relief valve 20b of 0 becomes O according to the predetermined duty ratio.
N / OFF, the braking pressure is reduced according to a predetermined gradient and the braking force is gradually reduced, and the rotational force of the front wheels 1 is restored accordingly, as indicated by reference numeral (a) in the figure. start.

When the deceleration DW1 and the acceleration AW1 obtained from the wheel speed W1 of the front wheels 1 become 0 respectively after further reduction of the braking pressure, the ECU 24 changes the phase value P1 from 3 to 5. Therefore, the reference numeral (a) in the figure
As shown by, the braking pressure is maintained at the level after the pressure reduction. When the state of phase 5 continues and the slip ratio S1 exceeds 90%, the ECU 24
As shown in (c), the continuation flag Fc is set to 1. As a result, the ABS control on the first channel shifts from the first cycle immediately after the start of control to the second cycle. In that case, the ECU 24 determines that the phase value P1
Is forced to change to 1.

Immediately after the shift to the phase 1, the opening / closing valve 20b of the first valve unit 20 is set in accordance with the initial rapid pressure increase time Tpz set based on the duration of the phase 5 in the first cycle. The opening / closing is performed at a duty ratio of 100%, and the braking pressure is steeply increased, as indicated by the symbol (c) in the figure. After the initial rapid pressure increase time Tpz ends, the on-off valve 20a is turned on / off in accordance with a predetermined duty ratio, and the braking pressure has a gentler gradient than the above-mentioned gradient, as indicated by symbol (d) in the figure. Will gradually rise. When the ECU 24 determines that the slip ratio S1 is larger than the 5-1 slip ratio threshold Bsz in the phase 5 state in the second cycle, the ECU 24 sets the phase value P1 to 1 and shifts to the third cycle.

When the friction coefficient value MU is set to 1 which indicates a low μ road surface, when the wheel speed W1 is reduced to the first set value V1 as indicated by the reference numeral (e) in FIG. , The ECU 24 clears the lock flag Fl1 and the continuation flag Fc in the first channel to 0, respectively, as shown in (a) and (b) of FIG. At that time, since the friction coefficient value MU is set to 1 indicating the low μ road surface as described above, the ECU 24 more preferably sets the slow pressure increase control amount and outputs the braking pressure control signal corresponding thereto. Output to the first valve unit 20. As a result, the braking pressure gradually increases as indicated by the symbol (F), and the locked or skid state of the left front wheel 1 is avoided. Immediately before the vehicle stops, the braking pressure control as described above is similarly performed for the second and third channels, so that the left and right front wheels 1, 2 and the rear wheels 3, 4 are locked. Moreover, the occurrence of the skid state is prevented, and the vehicle can be stably stopped even on a low μ road surface such as an ice burn.

On the other hand, the friction coefficient value MU is 3 indicating a high μ road surface.
When the wheel speed W1 is reduced to the second set value V2 this time, as shown by the symbol (g) in FIG. ), The lock flag Fl on the first channel
The 1 and the continuation flag Fc are each cleared to 0, and the process is shifted to the end process from that point. This allows
Compared with the case where the ABS control is continued until the wheel speed W1 drops to the first set value V1, the probability that the braking pressure is unexpectedly reduced is reduced, and the driver does not feel an unnecessarily idling feeling. . Moreover, since the front wheels 1 reliably grip the road surface, the front wheels 1 are not locked or skid, and the running stability is not impaired. Further, the ECU 24 sets the normal pressure increase control amount when the wheel speed W1 decreases to the second set value T2, and outputs a braking pressure control signal corresponding thereto to the first valve unit 20. So the sign
As indicated by (h), the braking pressure rises more quickly than when the μ is low, and the vehicle is surely stopped.

By the way, in the present embodiment, as a wheel speed detecting device for detecting the wheel speed of each of the wheels 1 to 4, as described above, the magnetic flux change is converted into a voltage signal and a pulsed output signal is output. A so-called electromagnetic pickup type wheel speed sensor 26-29 is used. That is, for example, taking the one for the front left wheel 26 as an example, as shown in FIG. 6, the wheel speed sensor 26 includes a permanent magnet 26b and a coil 26c for voltage generation, and the pickup section 26a thereof is The gear-shaped (or sawtooth-shaped) tooth-shaped rotor 31 that rotates integrally with the wheel 1 is mounted so as to be located near the outer peripheral portion. In this example,
As the tooth profile rotor 31, one having 44 teeth is used. Then, when the tooth profile rotor 31 rotates as the wheel 1 rotates, the tooth portions 31a, ..., 31a of the tooth profile rotor 31 pass near the pickup 26a, so that a change in magnetic flux occurs in the voltage generating coil 26c. Occurs,
According to this, the voltage signal is output.
In this case, the voltage signal is output in pulses each time the tooth portions 31a, ..., 31a pass near the pickup portion 26a as the tooth-shaped rotor 31 rotates.

The electromagnetic pickup type wheel speed sensor 2
As described above, 6 to 29 are for converting the magnetic flux change into a voltage signal and outputting the signal, so that when there is a large change in the external magnetic field, it is affected by this magnetic field change and the output signal is noisy. May be superimposed, or noise may appear as an output signal when the wheel speed is actually 0 km / hr and there is no output. Specifically, as described above, when the Shinkansen passes through the vicinity of the above-mentioned automobile, when the Shinkansen normally passes a current of a large value of 60 Hz alternating current when it passes, Is 60H
A magnetic field change of z cycles will result. In this case, if the traveling speed of the vehicle is high to some extent, as shown in FIG. 7, the original signal level Vp output from the wheel speed sensors 26 to 29 is high (the output is large), and therefore the noise Vn (in FIG. 7) is generated. Even if (dotted line) is superimposed, it is unlikely that it will affect the detected value of the wheel speed, but when the car is stopped or running at a very low speed, The influence of the noise Vn becomes so great.

In the wheel speed detecting apparatus according to this embodiment, the tooth-shaped rotor 31 having 44 teeth is used. In the case of this number of teeth, the magnetic field change caused by the alternating current 60 Hz is about 9 km / hour in terms of speed. Equivalent to hr. Therefore, the wheel speed detection device outputs a voltage signal on which noise corresponding to the speed of about 9 km / hr is superimposed as the Shinkansen passes. That is, the car itself actually stops running
Although the vehicle travels only at a vehicle speed of 0 km / hr or at an extremely low vehicle speed, the wheel speed detection device detects a wheel speed on which a value of 9 km / hr is superimposed as noise.

The strength (magnitude) of this noise is, for example, as shown in FIG.
As shown in, the signal level Va (see the alternate long and short dash line in FIG. 8) read by the ABS control device changes depending on the magnitude of the power load of the Shinkansen vehicle, and the read signal level and the noise level are The anti-skid control device reads or does not read the noise signal Vn of 9 km / hr depending on the magnitude relationship of the above.
That is, the noise signal Vn of 9 km / hr may or may not be input to the anti-skid control device side. Then, when this noise signal Vn of 9 km / hr is input to the anti-skid control device side and then this signal is not input, the wheel speed is rapidly decelerated from 9 km / hr to 0 (zero) km / hr. As a result, execution of anti-skid control may be started.

In this embodiment, when there is a change in the external magnetic field, the change in the magnetic field affects the wheel speed sensors 26 to 29, and noise is superimposed on the output signal, or there is no actual output. However, if noise appears as an output signal, this noise can be reliably discriminated.
The S control device is designed to prevent the control from being started in an operating state where the S control device does not normally operate. Less than,
Discrimination of noise due to the change of the external magnetic field and operation control of the ABS control device when the noise occurs will be described with reference to the flowcharts of FIGS. 9 and 10.

When the system starts, it is first determined in step S31 whether or not the noise flag Fn is set to 1. The noise flag Fn is set to 1 while it is determined that the output signals from the wheel speed sensors 26 to 29 are noise due to changes in the external magnetic field, and when the output signals are not noise and the noise determination is canceled. It is a flag that is set or cleared to 0 when it is performed. If the determination result in step S31 is NO, in step S32, the wheel speed sensors 26 to
For No. 29, it is determined whether or not there is no pulse (that is, the wheel speed is 0 km / hr), and the result of this determination is YES.
In the case of, in step S33, the wheel speed sensors 26-2
It is determined from 9 whether or not the pulse signal is output.
If the decision result in the step S33 is YES,
Next, in step S34, for each of the wheel speed sensors 26 to 29 that have output a pulse signal, the pulse cycle from the start of output to a predetermined number of times (specifically, in the present embodiment, the first pulse from the non-pulse state). It is determined whether or not the rising and falling periods of the pulse of (4) correspond to a frequency within a predetermined range (specifically, 50 to 60 Hz in this embodiment).

The determination result of step S34 is YES.
In this case, in step S35, a pulse signal corresponding to a pulse rising / falling cycle of the first pulse from the pulse-free state as described above corresponding to 50 to 60 Hz is 4
More than a predetermined number of wheel speed sensors 26-29
It is determined whether or not (at least two or more in this embodiment) wheel speed sensors are outputting. Then, if the decision result in the step S35 is YES, a noise flag is set to 1 in a step S36. That is, the output signals from the wheel speed sensors 26 to 29 are determined to be noise due to changes in the external magnetic field.

As described above, according to this embodiment, when the wheel speed sensors 26 to 29 output the pulse signals from the non-pulse state, the output signals are output according to the pulse cycle from the start of the output to the predetermined number of times. It is possible to determine whether or not is noise due to a change in the external magnetic field. That is, in the normal state without noise, the wheel speed sensor 2
No pulse from 6 to 29 (that is, wheel speed 0km / hr)
When the pulse signal is output from (that is, when the speed at the time of starting the wheel is detected), the number of pulses is usually gradually increased to some extent at first. Until then, the pulse number (that is, the wheel speed) does not suddenly rise to a high value,
The period of the pulse during that time is quite long. In other words, the frequency corresponding to that is quite low. Therefore, when the wheel speed sensors 26 to 29 output the pulse signal from the non-pulse state, whether or not the cycle of the pulse signal from the start of the output to the predetermined number of times has a frequency of a height that does not normally occur at the time of starting the wheel. By determining, it is possible to determine whether or not the output signal is noise due to a change in the external magnetic field. The above-mentioned noise determination can be performed by providing a noise determination unit mainly composed of a microcomputer in the wheel speed detection device and by this noise determination unit. Control unit (ECU
A noise determination unit may be provided in 24) to perform noise determination.

In particular, in the present embodiment, the pulse cycle from the start of output to the predetermined number of times is the first pulse rise from the non-pulse state where the pulse cycle is the longest in a normal state without noise. Since the cycle is the falling period, more reliable noise determination can be performed. still,
The predetermined number of times may be set to a few times after the start of output, for example, a few times.

In this embodiment, in particular, the frequency in the above-mentioned predetermined range is set to 50 to 60 Hz.
When the high current of Hz passes through the vicinity of the own vehicle of the Shinkansen used for the drive system, noise due to the change of the external magnetic field accompanying the passage of the Shinkansen can be surely discriminated. It is to be noted that, as described above, the drive system of the Shinkansen is normally supplied with an alternating current of 60 Hz, but in the present embodiment, the frequency range is set to 50 to 60 Hz in consideration of a frequency error. If it is expected that this frequency error will be above or below the usual 60 Hz, the above frequency range will be 60 Hz.
It may be set up and down (including 60 Hz ± 5 Hz) including.

Further, in the present embodiment, from the state in which the wheel speed sensors 26 to 29 of all four wheels are pulseless, a predetermined plurality of wheel speed sensors (at least two or more) are provided.
When a pulse signal corresponding to a frequency of 50 to 60 Hz in the rising and falling periods of the first pulse of the output start is output, the output signals from the wheel speed sensors 26 to 29 are due to changes in the external magnetic field. Since it is determined that there is noise, it is possible to perform more reliable noise determination as compared with the case where determination is made only by the output of the wheel speed sensor for one wheel. Instead of this, from the state in which the wheel speed sensors 26 to 29 of all four wheels are pulseless, at least 1
For the wheel speed sensor of the wheel, the cycle of rising and falling of the first pulse of the output start is 50 to 60 Hz.
When the pulse signal corresponding to the frequency is output, the output signals from the wheel speed sensors 26 to 29 may be determined to be noise due to changes in the external magnetic field. In this case, it is possible to perform noise determination more quickly than in the above case.

Further, the judgment result of the step S32 is N
In the case of O, with respect to the wheel speed sensor which outputs the pulse signal, it is determined in step S37 whether or not the pulse signal of the frequency within the predetermined range (that is, 50 to 60 Hz) is continuously output for a certain time or more. And this judgment result is YES
In this case, in step S38, the wheel speed sensor is then put into a pulseless state, and it is determined whether or not the pulseless state has continued for a predetermined time or longer. If the determination result in step S38 is YES, it is determined that the output signal of the wheel speed sensor is noise due to the change in the external magnetic field. Of the four wheel speed sensors 26 to 29, the two wheel speed sensors are subjected to the above step S38.
If the determination result in step S36 is YES, step S36
The noise flag Fn is set to 1. On the other hand, the above steps S33 to S3
5 and the determination results in step S37 and step S38 are NO, the pulse signals output from the wheel speed sensors 26 to 29 are not noise due to changes in the external magnetic field, and thus the control of the brake control system is performed. The unit (ECU 24) performs normal control in step S39.

In this embodiment, as described above, after the pulse signal of the frequency (50 to 60 Hz) in the predetermined range is continuously output from the wheel speed sensor for a certain period of time, the non-pulse state is established. Whether or not the output signal is noise due to a change in the external magnetic field can be determined depending on whether or not the output signal is continued for a certain amount or more. That is, in a normal state where there is no noise, 50 to 50
After a pulse signal with a frequency of 60 Hz is continuously output for a certain period of time, that is, after the rotation speed of a wheel that rotates at a constant speed (about 9 km / hr) is continuously detected, a sudden pulseless state (that is, a wheel Since the speed becomes 0 (zero) km / hr), and this state is not continued, the wheel speed sensor 26 to
It is possible to reliably determine whether or not the output signal from 29 is noise due to a change in the external magnetic field.

In the above subroutine, when the output signals from the wheel speed sensors 26 to 29 are determined to be noise due to changes in the external magnetic field and the noise flag Fn is set to 1 (that is, step S36 is executed). (In case)
When the control cycle is repeated, step S3
The determination result in 1 is YES, and step S40 is executed. That is, during the noise determination period (that is, during the period when the noise flag Fn is set to 1), the ECU 24 limits the increase of the estimated value when estimating the pseudo vehicle body speed. In the present embodiment, specifically, when it is determined that the output signals from the wheel speed sensors 26 to 29 are due to noise, the estimated value of the pseudo vehicle body speed is prevented from further increasing from that time point. In other words, it is set to level off.

As described above, in this embodiment, when estimating the pseudo vehicle body speed of the vehicle based on the wheel speed detected by the wheel speed detecting device, the wheel speed sensor 26 is used.
When it is determined that the output signals from the output signals ˜29 are noises due to the change of the external magnetic field, the increase in the estimated value of the pseudo vehicle body speed is limited during the noise determination period. During the judgment period, it is possible to prevent the pseudo vehicle body speed, which is generally given as the highest value among the four wheel speeds, from becoming higher than the actual value due to the influence of noise, and the driver is not expecting a driving state. And AB
It is possible to prevent the S control from being executed. That is, it is possible to avoid the influence of noise due to the change of the external magnetic field without causing a large cost increase such as in the case of changing the number of teeth of the tooth profile rotor of the wheel speed detecting device.

During the noise determination period, instead of limiting the increase in the estimated value of the pseudo vehicle body speed as described above, it is possible to more reliably prevent the ABS control from being executed by the driver in an unexpected state. , The above pseudo vehicle speed is 0
The estimation may be made on the km / hr side. Further, during the noise determination period, in order to make it difficult to enter the ABS control, the minimum value of the wheel speed for performing the ABS control may be increased by a predetermined amount. In particular,
The minimum value of the wheel speed for performing the ABS control may be increased from the usual 7.5 km / hr to 10 km / hr or more.
Alternatively, the minimum value of the pseudo vehicle body speed for performing the ABS control is set by a predetermined amount (for example, from the normal 5 km / hr to 1
It may be increased (to 0 km / hr or more). Further, during the noise determination period, the control threshold for starting the ABS control may be changed to the side where it is difficult to enter the control in order to make it difficult to enter the ABS control.
Specifically, the control threshold value of the wheel deceleration for entering the ABS control may be changed from the normal -3G to -5G. Furthermore, during the noise determination period,
In order to reliably prevent the execution of ABS control, the ABS
The control may be prohibited from starting.

After step S40 is executed, whether or not the wheel speed sensors 26 to 29 have detected a wheel speed equal to or higher than a predetermined value in step S41, that is, whether the wheel speed sensors 26 to 29 have predetermined wheel speeds. It is determined whether or not the pulse signals corresponding to the above speeds have been output for a certain period of time or longer. If the result of this determination is NO, further, in step S42, the wheel speed sensors 26-
It is determined whether or not 29 continues the pulse-free state for a certain period of time or more. If the determination result is NO, step S3
After returning to 1, the subsequent steps are repeatedly executed. On the other hand, the above step S41 or step S42
If the result of the determination is YES in step S43,
The noise determination is canceled and the noise flag Fn is reset to 0.

As described above, according to this embodiment, the pulse from the wheel speed sensor after it is determined that the output signals from the wheel speed sensors 26 to 29 are noises due to the change of the external magnetic field. The noise determination can be canceled according to the output state of the signal. That is, when the rotation speed of the wheel is higher than a certain level, the original signal level output from the wheel speed sensor is high (the output is large), so even if noise is superimposed, the detected value of the wheel speed is substantially reduced. There is no problem even if the noise determination is canceled when the pulse signal corresponding to such a high wheel speed is output for a certain time or more without any influence. Therefore, by setting the predetermined wheel speed to an appropriate value of the height at which the corresponding pulse signal is not substantially affected by noise due to changes in the external magnetic field, it is possible to release the accurate noise determination. It can be done.

If the wheel speed sensor continues to be in the pulseless state for a certain period of time or more, it is considered that there is no noise. In such a case, the noise determination may be canceled. And, in particular, all four wheel speed sensors 26-2
Since the noise determination is canceled when 9 continues to be in the non-pulse state for a certain period of time, more accurate noise cancellation can be performed.

Although the above-mentioned embodiment is concerned with the wheel speed detecting device provided with the electromagnetic pickup type wheel speed sensors 26 to 29 and the ABS control device having the detecting device, the present invention is as described above. Not limited to the case, other slip control device provided with a wheel speed detection device of the type, for example, the drive wheel and the driven wheel based on the wheel speed detected by the wheel speed detection device as described above. The speed difference is calculated, and when the calculated value exceeds a predetermined value, at least one of the control for applying the braking force to the drive wheels and the control for reducing the engine output is performed, so-called traction. It can be effectively applied to a control device.

That is, depending on the direction of the wheel speed sensor attached to each wheel and the direction of the magnetic field generated by the passage of the Shinkansen, noise may occur only on the front wheel side or only on the rear wheel side due to changes in the external magnetic field. However, in a vehicle equipped with a traction control device, for example, if the vehicle is of a rear-wheel drive type, if noise occurs only on the rear wheel side, the speed of the drive wheel and the driven wheel will be affected by this noise. The difference appears to be larger than it actually is, and it is possible that the traction control is started when the speed difference exceeds the preset threshold value.The driver performs the traction control in an unexpected driving state. There was a problem that it made me feel uncomfortable.

In the case of this traction control device, when it is determined that the output signal from the wheel speed sensor is noise due to a change in the external magnetic field, at least the braking force is applied to the driving wheels during the noise determination period. By prohibiting the control to be applied, it is possible to prevent the driving wheels from being braked by the traction control in an unexpected driving state during the noise determination period. That is, it is possible to reliably avoid the influence of noise due to the change in the external magnetic field and prevent the driver from feeling uncomfortable. The noise determination and its cancellation in the case of this traction control device can be performed in the same manner as in the case of the ABS control device.

Further, in the case of the traction control device, when the wheel speed of the drive wheels does not change even after performing the traction control, the output signal from the wheel speed sensor of the drive wheels changes the external magnetic field. It is possible to determine that the noise is due to, and during this noise determination period,
By prohibiting the execution of the traction control, it is possible to prevent the driving wheels from being braked by the traction control in an unexpected driving state during the noise determination period.

[Brief description of drawings]

FIG. 1 is an explanatory plan view schematically showing an overall configuration of a vehicle braking system of an automobile according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a braking pressure control process in the vehicle brake control system.

FIG. 3 is a time chart showing a state before and after a shift to ABS control in the brake control system.

FIG. 4 is a time chart showing states before and after the end of ABS control on a low μ road.

FIG. 5 is a time chart showing states before and after ABS control on a high μ road.

FIG. 6 is an explanatory diagram of a wheel speed sensor mounted on the automobile.

FIG. 7 is an explanatory diagram showing an output level and a noise level of a wheel speed sensor in a high speed range.

FIG. 8 is an explanatory diagram showing a signal reading level and a noise level of the ABS control device at a low speed range or when the vehicle is stopped.

FIG. 9 is a part of a flowchart showing noise determination processing and determination cancellation processing in the brake control system.

FIG. 10 is a part of a flowchart showing noise determination processing and determination cancellation processing in the brake control system.

[Explanation of symbols]

 1, 2, 3, 4 ... Wheels 24 ... Control unit (ECU) 26, 27, 28, 29 ... Wheel speed sensor Vr ... Pseudo vehicle speed W1, W2, W3, W4 ... Wheel speed

Claims (37)

[Claims] 1. An electromagnetic pickup type wheel speed sensor for converting a magnetic flux change into a voltage signal and outputting a pulse signal having a frequency corresponding to the frequency of the magnetic flux change, based on an output signal from the wheel speed sensor. A wheel speed detection device for detecting a wheel speed, wherein the wheel speed sensor outputs a pulse signal from a non-pulse state, when the period of the pulse from the output start to a predetermined number of times corresponds to a frequency in a predetermined range, A wheel speed detecting device, wherein the output signal from the wheel speed sensor is determined to be noise due to a change in an external magnetic field. 2. An electromagnetic pickup type wheel speed sensor for converting a magnetic flux change into a voltage signal and outputting a pulse signal having a frequency corresponding to the frequency of the magnetic flux change, based on an output signal from the wheel speed sensor. A wheel speed detecting device for detecting a wheel speed, wherein the wheel speed sensor is attached to each of four wheels of a vehicle, and at least one wheel speed sensor from all four wheel speed sensors is pulseless. When a pulse signal whose pulse period from the start of output to a predetermined number of times corresponds to a frequency within a predetermined range is output, the output signal from each wheel speed sensor is a noise due to a change in the external magnetic field. A wheel speed detecting device characterized by determining that there is. 3. An electromagnetic pickup type wheel speed sensor for converting a change in magnetic flux into a voltage signal and outputting a pulse signal having a frequency corresponding to the frequency of the change in magnetic flux, based on an output signal from the wheel speed sensor. A wheel speed detecting device for detecting a wheel speed, wherein the wheel speed sensor is attached to each of four wheels of a vehicle, and the wheel speed sensors of all four wheels are pulseless, and a predetermined number of wheels are detected. For more than one wheel speed sensor, when a pulse signal corresponding to a frequency within a predetermined range of the pulse period from the start of output to a predetermined number of times is output, the output signal from each wheel speed sensor is due to a change in the external magnetic field. A wheel speed detection device characterized by determining that it is noise. 4. The pulse cycle from the start of output to a predetermined number of times is a cycle of rising and falling of the first pulse from a non-pulse state.
~ The wheel speed detecting device according to claim 3. 5. An electromagnetic pickup type wheel speed sensor for converting a change in magnetic flux into a voltage signal and outputting a pulse signal having a frequency corresponding to the frequency of the change in magnetic flux is provided, and based on an output signal from the wheel speed sensor. A wheel speed detection device for detecting a wheel speed, wherein a pulse signal having a frequency in a predetermined range is continuously output from the wheel speed sensor for a certain period of time, and then a non-pulse state is set,
When this non-pulse state continues for a predetermined time or more,
A wheel speed detecting device, wherein the output signal from the wheel speed sensor is determined to be noise due to a change in an external magnetic field. 6. An electromagnetic pickup type wheel speed sensor for converting a magnetic flux change into a voltage signal and outputting a pulse signal having a frequency corresponding to the frequency of the magnetic flux change, based on an output signal from the wheel speed sensor. A wheel speed detecting device for detecting a wheel speed, wherein the wheel speed sensor is attached to each of four wheels of a vehicle, and at least one of the four wheel speed sensors has a predetermined wheel speed sensor. After the pulse signal with a frequency within the range is continuously output for a certain period of time, it becomes a pulseless state, and when this pulseless state is continued for a predetermined time or longer, the output signal from each wheel speed sensor is due to the change of the external magnetic field. A wheel speed detection device characterized by determining that it is noise. 7. An electromagnetic pickup type wheel speed sensor for converting a change in magnetic flux into a voltage signal and outputting a pulse signal having a frequency corresponding to the frequency of the change in magnetic flux, based on an output signal from the wheel speed sensor. A wheel speed detecting device for detecting a wheel speed, wherein the wheel speed sensor is attached to each of four wheels of a vehicle. , After a pulse signal of a frequency in a predetermined range is continuously output for a certain period of time, it becomes a pulseless state, and when this pulseless state is continued for a predetermined period of time or more, the output signal from each wheel speed sensor is an external magnetic field. A wheel speed detecting device, characterized in that it is determined to be noise due to a change. 8. The frequency within the predetermined range is 50 to 60 Hz.
The wheel speed detecting device according to any one of claims 1 to 7, wherein 9. An electromagnetic pickup type wheel speed sensor for converting a change in magnetic flux into a voltage signal and outputting a pulse signal having a frequency corresponding to the frequency of the change in magnetic flux, based on an output signal from the wheel speed sensor. A wheel speed detecting device for detecting a wheel speed, which is equivalent to a speed equal to or higher than a predetermined wheel speed from the wheel speed sensor after it is determined that the output signal from the wheel speed sensor is noise due to a change in an external magnetic field. The wheel speed detecting device is characterized in that the noise determination is canceled when the pulse signal to be output is output for a certain time or more. 10. An electromagnetic pickup type wheel speed sensor for converting a change in magnetic flux into a voltage signal and outputting a pulse signal having a frequency corresponding to the frequency of the change in magnetic flux, based on an output signal from the wheel speed sensor. A wheel speed detecting device for detecting a wheel speed, wherein the wheel speed sensor is attached to each of four wheels of a vehicle, and an output signal from these wheel speed sensors is determined to be noise due to a change in an external magnetic field. After that, when the wheel speed sensors of all the four wheels continue to be in a pulseless state for a certain period of time or more, the noise determination is canceled. 11. A wheel speed for detecting a wheel speed based on an output signal from an electromagnetic pickup type wheel speed sensor which converts a change in magnetic flux into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the change in magnetic flux. A detection device, hydraulic pressure adjusting means for adjusting the braking pressure of each wheel, and operating the hydraulic pressure adjusting means based on the wheel speed detected by the wheel speed detecting device cyclically increases or decreases the braking pressure of each wheel. A slip control device for a wheel, comprising: an anti-skid control means, wherein the wheel speed sensor outputs a pulse signal from a non-pulse state, a period of a pulse from the start of output to a predetermined number of times is a frequency within a predetermined range. The output signal from the wheel speed sensor is determined to be noise due to a change in the external magnetic field. -Up control device. 12. A wheel speed for detecting a wheel speed based on an output signal from an electromagnetic pickup type wheel speed sensor which converts a change in magnetic flux into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the change in magnetic flux. A detection device, hydraulic pressure adjusting means for adjusting the braking pressure of each wheel, and operating the hydraulic pressure adjusting means based on the wheel speed detected by the wheel speed detecting device cyclically increases or decreases the braking pressure of each wheel. A slip control device for a wheel comprising anti-skid control means for controlling the wheel speed sensor, wherein the wheel speed sensor is attached to each of four wheels of a vehicle, and the wheel speed sensors of all four wheels are pulseless. From at least one wheel speed sensor, a pulse signal whose pulse period from the start of output to a predetermined number of times corresponds to a frequency within a predetermined range is output. Been the case, the output signal from each wheel speed sensor wheel slip control system, characterized in that it is determined that a noise due to changes in the external magnetic field. 13. A wheel speed for detecting a wheel speed based on an output signal from a wheel speed sensor of an electromagnetic pickup type which converts a change in magnetic flux into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the change in magnetic flux. A detection device, hydraulic pressure adjusting means for adjusting the braking pressure of each wheel, and operating the hydraulic pressure adjusting means based on the wheel speed detected by the wheel speed detecting device cyclically increases or decreases the braking pressure of each wheel. A slip control device for a wheel comprising anti-skid control means for controlling the wheel speed sensor, wherein the wheel speed sensor is attached to each of four wheels of a vehicle, and the wheel speed sensors of all four wheels are pulseless. Therefore, for a plurality of wheel speed sensors of a predetermined number or more, a pulse signal whose pulse period from the output start to a predetermined number of times corresponds to a frequency in a predetermined range is generated. When it is force, the output signals from the wheel speed sensor wheel slip control system, characterized in that it is determined that a noise due to changes in the external magnetic field. 14. The pulse cycle from the start of output to a predetermined number of times is a cycle of rising and falling of the first pulse from a non-pulse state, according to any one of claims 11 to 13. The slip control device for a wheel described in 1. 15. A wheel speed for detecting a wheel speed based on an output signal from an electromagnetic pickup type wheel speed sensor which converts a change in magnetic flux into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the change in magnetic flux. A detection device, hydraulic pressure adjusting means for adjusting the braking pressure of each wheel, and operating the hydraulic pressure adjusting means based on the wheel speed detected by the wheel speed detecting device cyclically increases or decreases the braking pressure of each wheel. A wheel slip control device comprising an anti-skid control means for performing a pulse-free state after a pulse signal having a frequency in a predetermined range is continuously output from the wheel speed sensor for a certain period of time,
When this non-pulse state continues for a predetermined time or more,
A slip control device for a wheel, wherein an output signal from the wheel speed sensor is determined to be noise due to a change in an external magnetic field. 16. A wheel speed for detecting a wheel speed based on an output signal from a wheel speed sensor of an electromagnetic pickup type which converts a change in magnetic flux into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the change in magnetic flux. A detection device, hydraulic pressure adjusting means for adjusting the braking pressure of each wheel, and operating the hydraulic pressure adjusting means based on the wheel speed detected by the wheel speed detecting device cyclically increases or decreases the braking pressure of each wheel. Anti-skid control means for controlling the wheel slip, wherein the wheel speed sensor is attached to each of the four wheels of the vehicle, and at least one of the four wheel speed sensors is a wheel. Regarding the speed sensor, a pulse signal with a frequency within a predetermined range is continuously output for a certain period of time, and then becomes a non-pulse state. When it is continued, the output signal from the wheel speed sensor wheel slip control system, characterized in that it is determined that a noise due to changes in the external magnetic field. 17. A wheel speed for detecting a wheel speed based on an output signal from a wheel speed sensor of an electromagnetic pickup type which converts a change in magnetic flux into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the change in magnetic flux. A detection device, hydraulic pressure adjusting means for adjusting the braking pressure of each wheel, and operating the hydraulic pressure adjusting means based on the wheel speed detected by the wheel speed detecting device cyclically increases or decreases the braking pressure of each wheel. Anti-skid control means for controlling the wheel slip, wherein the wheel speed sensor is attached to each of the four wheels of the vehicle. For the wheel speed sensor of, the pulse signal of the frequency within the predetermined range is continuously output for a certain period of time, and then the non-pulse state is set. When it is above continues, the output signal from the wheel speed sensor wheel slip control system, characterized in that it is determined that a noise due to changes in the external magnetic field. 18. The frequency within the predetermined range is 50 to 60H.
The wheel slip control device according to any one of claims 11 to 17, wherein z is z. 19. A wheel speed for detecting a wheel speed based on an output signal from a wheel speed sensor of an electromagnetic pickup type which converts a change in magnetic flux into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the change in magnetic flux. A detection device, hydraulic pressure adjusting means for adjusting the braking pressure of each wheel, and operating the hydraulic pressure adjusting means based on the wheel speed detected by the wheel speed detecting device cyclically increases or decreases the braking pressure of each wheel. A slip control device for a wheel, comprising: an anti-skid control means for controlling a predetermined wheel speed from the wheel speed sensor after the output signal from the wheel speed sensor is determined to be noise due to a change in an external magnetic field. When the pulse signals corresponding to the above speeds are output for a certain period of time or more, the above noise determination is canceled, and the wheel slip is characterized. The control device. 20. A wheel speed for detecting a wheel speed based on an output signal from a wheel speed sensor of an electromagnetic pickup type which converts a change in magnetic flux into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the change in magnetic flux. A detection device, hydraulic pressure adjusting means for adjusting the braking pressure of each wheel, and operating the hydraulic pressure adjusting means based on the wheel speed detected by the wheel speed detecting device cyclically increases or decreases the braking pressure of each wheel. Anti-skid control means for controlling the wheel slip, wherein the wheel speed sensors are attached to each of the four wheels of the vehicle, and the output signals from the wheel speed sensors depend on changes in the external magnetic field. After it is determined that there is noise, the noise determination is canceled when the wheel speed sensors of all the four wheels continue to be in the non-pulse state for a certain period of time or more. Wheel slip control system, characterized in that. 21. When the wheel slip control device estimates a pseudo vehicle body speed of the vehicle based on the wheel speed detected by the wheel speed detection device, an output signal from the wheel speed sensor outputs an external magnetic field. 21. When it is determined that the noise is due to a change in the noise, the increase in the estimated value of the pseudo vehicle body speed is limited during the noise determination period. A slip control device for a wheel according to item 1. 22. When the wheel slip control device estimates the pseudo vehicle body speed of the vehicle based on the wheel speed detected by the wheel speed detection device, an output signal from the wheel speed sensor outputs an external magnetic field. 21. When it is determined that the noise is due to a change in the noise, the pseudo vehicle body speed is estimated to be 0 km / hr during the noise determination period. A slip control device for a wheel according to item 1. 23. When the output signal from the wheel speed sensor is determined to be noise due to a change in an external magnetic field, the wheel slip control device controls the anti-skid control during the noise determination period. The wheel slip control device according to any one of claims 11 to 20, wherein the minimum value of the wheel speed for performing the above is increased by a predetermined amount. 24. If the output signal from the wheel speed sensor is determined to be noise due to a change in an external magnetic field, the wheel slip control device is configured to perform the anti-skid control during the noise determination period. The wheel slip control device according to any one of claims 11 to 20, wherein a control threshold for starting the control is changed to a side in which control is difficult to enter. 25. When the output signal from the wheel speed sensor is determined to be noise due to a change in an external magnetic field, the wheel slip control device is configured to perform the anti-skid control during the noise determination period. 21. The wheel slip control device according to claim 11, wherein the start of the slip control is prohibited. 26. A wheel speed for detecting a wheel speed based on an output signal from an electromagnetic pickup type wheel speed sensor which converts a change in magnetic flux into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the change in magnetic flux. The speed difference between the drive wheel and the driven wheel is calculated based on the wheel speed detected by the detection device and the wheel speed detection device. When the calculated value exceeds a predetermined value, the braking force is applied to the drive wheel. A wheel slip control device comprising a traction control means for performing at least one of control for operating and control for reducing engine output, wherein the wheel speed sensor outputs a pulse signal from a non-pulse state, When the pulse cycle from the start of output up to a predetermined number of times corresponds to a frequency within a predetermined range, the output signal from the wheel speed sensor is due to a change in the external magnetic field. A wheel slip control device characterized by being determined to be noise. 27. A wheel speed for detecting a wheel speed based on an output signal from an electromagnetic pickup type wheel speed sensor which converts a change in magnetic flux into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the change in magnetic flux. The speed difference between the drive wheel and the driven wheel is calculated based on the wheel speed detected by the detection device and the wheel speed detection device. When the calculated value exceeds a predetermined value, the braking force is applied to the drive wheel. A slip control device for a wheel, comprising a traction control means for performing at least one of a control for operating and a control for reducing an engine output, wherein the wheel speed sensor is attached to each of four wheels of a vehicle. From the state in which the wheel speed sensors of all four wheels are pulseless, the pulse speed of at least one wheel speed sensor is output from the start of output to a predetermined number of times. When a pulse signal corresponding to a frequency of a predetermined range is output, the output signal from each wheel speed sensor is determined to be noise due to a change in the external magnetic field. . 28. A wheel speed for detecting a wheel speed based on an output signal from a wheel speed sensor of an electromagnetic pickup type which converts a change in magnetic flux into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the change in magnetic flux. The speed difference between the drive wheel and the driven wheel is calculated based on the wheel speed detected by the detection device and the wheel speed detection device. When the calculated value exceeds a predetermined value, the braking force is applied to the drive wheel. A slip control device for a wheel, comprising a traction control means for performing at least one of a control for operating and a control for reducing an engine output, wherein the wheel speed sensor is attached to each of four wheels of a vehicle. From the state in which the wheel speed sensors of all four wheels are pulse-free, a predetermined number of wheel speed sensors or more are output from the start of output to a predetermined number of times. The slip control of the wheel is characterized in that, when a pulse signal corresponding to a frequency of a predetermined range is output, the output signal from each wheel speed sensor is determined to be noise due to a change in the external magnetic field. apparatus. 29. The cycle of a pulse from the start of output to a predetermined number of times is a cycle of rising and falling of the first pulse from a non-pulse state, according to any one of claims 26 to 28. The slip control device for a wheel described in 1. 30. A wheel speed for detecting a wheel speed based on an output signal from an electromagnetic pickup type wheel speed sensor which converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. The speed difference between the drive wheel and the driven wheel is calculated based on the wheel speed detected by the detection device and the wheel speed detection device. When the calculated value exceeds a predetermined value, the braking force is applied to the drive wheel. A wheel slip control device comprising traction control means for performing at least one of control for operating and control for reducing engine output, wherein a pulse signal of a frequency in a predetermined range from the wheel speed sensor continues for a certain period of time. After being output,
When this non-pulse state continues for a predetermined time or more,
A slip control device for a wheel, wherein an output signal from the wheel speed sensor is determined to be noise due to a change in an external magnetic field. 31. A wheel speed for detecting a wheel speed based on an output signal from an electromagnetic pickup type wheel speed sensor which converts a change in magnetic flux into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the change in magnetic flux. The speed difference between the drive wheel and the driven wheel is calculated based on the wheel speed detected by the detection device and the wheel speed detection device. When the calculated value exceeds a predetermined value, the braking force is applied to the drive wheel. A slip control device for a wheel, comprising a traction control means for performing at least one of a control for operating and a control for reducing an engine output, wherein the wheel speed sensor is attached to each of four wheels of a vehicle. After a pulse signal having a frequency within a predetermined range is continuously output for a certain period of time with respect to at least one wheel speed sensor among these four wheel speed sensors, When there is no pulse, and when this non-pulse state continues for a predetermined time or longer, the output signal from each wheel speed sensor is determined to be noise due to a change in the external magnetic field. . 32. A wheel speed for detecting a wheel speed based on an output signal from an electromagnetic pickup type wheel speed sensor which converts a magnetic flux change into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the magnetic flux change. The speed difference between the drive wheel and the driven wheel is calculated based on the wheel speed detected by the detection device and the wheel speed detection device. When the calculated value exceeds a predetermined value, the braking force is applied to the drive wheel. A slip control device for a wheel, comprising a traction control means for performing at least one of a control for operating and a control for reducing an engine output, wherein the wheel speed sensor is attached to each of four wheels of a vehicle. A pulse signal having a frequency within a predetermined range is continuously output for a certain period of time from a plurality of predetermined wheel speed sensors among the four wheel speed sensors. The slip control of the wheel is characterized in that the output signal from each wheel speed sensor is determined to be noise due to a change in the external magnetic field when the non-pulse state is maintained for a predetermined time or more. apparatus. 33. The frequency within the predetermined range is 50 to 60H.
33. The wheel slip control device according to claim 26, wherein z is z. 34. A wheel speed for detecting a wheel speed based on an output signal from an electromagnetic pickup type wheel speed sensor which converts a change in magnetic flux into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the change in magnetic flux. The speed difference between the drive wheel and the driven wheel is calculated based on the wheel speed detected by the detection device and the wheel speed detection device. When the calculated value exceeds a predetermined value, the braking force is applied to the drive wheel. A slip control device for a wheel, comprising a traction control means for performing at least one of a control for operating and a control for reducing an engine output, wherein an output signal from the wheel speed sensor is noise due to a change in an external magnetic field. When it is determined that the pulse signal corresponding to a speed equal to or higher than a predetermined wheel speed is output from the wheel speed sensor for a certain period of time or more, Wheel slip control system, wherein a size determination is canceled. 35. A wheel speed for detecting a wheel speed based on an output signal from an electromagnetic pickup type wheel speed sensor which converts a change in magnetic flux into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the change in magnetic flux. The speed difference between the drive wheel and the driven wheel is calculated based on the wheel speed detected by the detection device and the wheel speed detection device. When the calculated value exceeds a predetermined value, the braking force is applied to the drive wheel. A slip control device for a wheel, comprising a traction control means for performing at least one of a control for operating and a control for reducing an engine output, wherein the wheel speed sensor is attached to each of four wheels of a vehicle. After it is determined that the output signals from these wheel speed sensors are noise due to the change in the external magnetic field, the wheel speed sensors of all the four wheels have no noise for a certain period of time. The scan state upon continued, the wheel slip control system, characterized in that the noise determination is canceled. 36. When the output signal from the wheel speed sensor is determined to be noise due to a change in an external magnetic field, the wheel slip control device at least the drive wheel during the noise determination period. The wheel slip control device according to any one of claims 26 to 35, characterized in that the control for applying a braking force to the wheel is prohibited. 37. A wheel speed for detecting a wheel speed based on an output signal from an electromagnetic pickup type wheel speed sensor which converts a change in magnetic flux into a voltage signal and outputs a pulse signal having a frequency corresponding to the frequency of the change in magnetic flux. The speed difference between the drive wheel and the driven wheel is calculated based on the wheel speed detected by the detection device and the wheel speed detection device. When the calculated value exceeds a predetermined value, the braking force is applied to the drive wheel. A slip control device for a wheel, comprising a traction control means for performing at least one of a control for acting and a control for reducing an engine output, wherein the wheel speed of the drive wheel does not change even after performing the traction control. It is determined that the output signal from the wheel speed sensor of the drive wheel is noise due to a change in the external magnetic field. Wheel slip control system, characterized in that the execution of Rakushon control is prohibited.