JPS62218256A - Antiskid brake controller - Google Patents

Abstract

PURPOSE:To detect a rotating speed of each wheel in succession as well as to perform stable control over them, by measuring each period of pulse signals produced as corresponding to the rotating speed of each wheel, and displaying the state that this measurement is completed, on a hold bit holding circuit. CONSTITUTION:Each rotating speed of respective axles A1-An is detected as each period of wheel speed pulses by each of wheel speed sensors 1-1-1-N, and this period is measured by a pulse period counter circuit 2-1. And, the measuring result is set to each of hold bit holding circuits 3-1-3-N as a hold bit. And, these hold bit holding circuits 3-1-3-N are scanned by a control part 4 and, after reading the measured value from respective pulse period counter circuits 2-1-2-N corresponding to such ones where the hold bit so set, resetting takes place. Afterward, a control signal optimum to the read wheel speed is outputted to each of antiskid control parts 5-1-5-N, controlling each of wheels W1-Wn.

Description

[Detailed Description of the Invention] [Summary] In an anti-skid brake control device that performs brake control corresponding to the speed of each wheel, a pulse period counting circuit calculates the period of a pulse signal of a sensor output generated according to the rotational speed of each wheel. Measured by.

The state that this measurement has been completed is set in a hold bit (flag), and the hold bit is scanned from the CPU asynchronously with the pulse signal output from the wheel speed sensor, and the pulse period counting circuit that has completed the measurement is By reading the measured values.

Brake control is performed by detecting the speed of each wheel.

[Industrial application field]

The present invention relates to an antiskid brake control device that detects the speed of each wheel and performs brake control.

[Conventional technology]

Conventionally, devices that detect the speed of each wheel of a car or the like and perform anti-skin brake control use a pulse signal generated by a sensor according to the rotational speed of each wheel as an interrupt input signal, and use this interrupt human input signal as an interrupt input signal. C as an opportunity
The PU detects the speed of each wheel by starting a timer and stopping the timer in response to a primary interrupt input signal.

Brake control optimal for each detected speed was applied to each wheel.

[Problem that the invention seeks to solve]

Therefore, when the wheel speed is high, for example around 250 km/h, the interval (period) of wheel speed pulses generated according to the speed becomes shorter, reducing the time required for interrupt processing to measure the speed. or you may need to temporarily disable interrupts. This becomes a major constraint when creating a program used for one interrupt processing.

Also.

If the number of interrupt terminals is insufficient, it is necessary to sequentially switch and input a plurality of wheel speed pulses to one interrupt terminal.

Therefore, the switching is unstable at the beginning.

It is necessary to read the wheel speed pulse after it has stabilized, and if the wheel speed pulses arrive at the same time, only one of them can be read.

For those that could not be read, there was a problem in that the measurement interval of wheel speed pulses became significantly longer, especially at low speeds, making anti-skid control unstable.

[Means for solving problems]

In order to solve the above problem, the present invention uses a pulse period counting circuit to measure the period of a pulse signal generated by a sensor corresponding to the rotational speed of each wheel.

The hold bit holding circuit that maintains the state that this measurement is completed is scanned and the measured value is read, and the pulse period counting circuit is reset to sequentially detect the speed of each wheel and perform anti-skin brake control. That's what I do.

FIG. 1 shows the basic configuration of the present invention. In the figure, 1-1 to 1-N are wheel speed sensors attached to axles A1 to A, l, 2-1 to 2-N are pulse period counting circuits,
3-1 to 3-N are hold bit holding circuits, 4 is a control section, and 5-1 to 5-N are anti-skinned brake control sections.

In FIG. 1, wheel speed sensors 1-1 to l-N are
This detects the rotation speed of the axles A1 to A7 connected to the wheels W1 to W7.

Note that n=N and 9 usually takes a value of 2 or 4.

The pulse period counting circuits 2-1 to 2-N measure the periods of wheel speed pulses detected by the pulse generators 1-1 to 1-N.

This shows a state in which measurement of the period of the wheel speed pulse has been completed by the pulse period counting circuits 2-1 to 2-N.

The control unit 4 includes hold bit holding circuits 3-1 to 3-.
After scanning N and reading the measured values from the pulse period counting circuits 2-1 to 2-N corresponding to those whose hold bits are set.

At the same time, the corresponding anti-skid brake control section 5-1 to 5-N is reset based on the read value.
It sends a control signal to perform appropriate anti-skid brake control.

The anti-skid brake control parts 5-1 to 5-N are
Based on the control signal from the control unit 4, the wheels WI to W7
The system performs anti-skid brake control on the vehicle.

[Operation] In the configuration shown in FIG. 1, the rotational speed of the axles AI to An is detected as a cycle of wheel speed pulses by the JIF wheel speed sensors 1-1 to 1-N4, respectively. The period of this detected wheel speed pulse is determined by the pulse period counting circuit 2-
Measured by 1. When this measurement is completed, hold bits are set in hold bit holding circuits 3-1 to 3-N. The control unit 4 scans the hold bit holding circuits 3-1 to 3-N and selects the pulse period counting circuit 2-1 corresponding to the hold bit holding circuit 3-1 to 3-N.
After reading the measured value from 2-N, reset.

Next, a control signal is sent to the anti-skid brake control units 5-1 to 5-N so as to perform anti-skid brake control optimal for the read wheel speed. The anti-skid brake control units 5-1 to 5-N that have received the notification of this control signal perform anti-skid brake control on the wheels W to Wn.

As explained above, the speed of each wheel is independently determined by the pulse period counting circuits 2-1 to 2-H, and the hold bit holding circuits 3-1 to 3-N hold the state that this measurement is completed. The wheel speed of each wheel is read by scanning, and anti-skid brake control is performed optimally for each wheel speed read, so that stable anti-skid brake control can be performed.

〔Example〕

FIG. 2 is a configuration diagram of one embodiment of the present invention, and FIG. 3 is an operational waveform diagram of the configuration shown in FIG. 2. In the figure, 6-1 is a waveform shaping circuit, 7-1 is an edge detection circuit, 8-1 to 8-N are counters, 9-1 to 9-N are buffers, 10 is a multiplexer, 11 is a hold bit holding circuit, 12 is CPU
(Central processing unit).

In FIG. 2, a waveform shaping circuit 6-1 shapes the waveform of the wheel speed pulse detected by the wheel speed sensor 1-1 into a rectangular wave.

The edge detection circuit 7-1 detects the rising edge of the wheel speed pulse shaped into a rectangular wave by the waveform shaping circuit 6-1.
Alternatively, a signal for one cycle is generated using a falling edge as a trigger.

The counters 8-1 to 8-N are the edge detection circuit 7-1.
This is to measure how many clocks are counted during one cycle of the wheel speed pulse generated by the wheel speed pulse.

Buffers 9-1 to 9-N hold the results (wheel speeds) measured by counters 8-1 to 8-N.

The multiplexer 10 includes buffers 9-1 to 9-, N
This selects which of the measured results held in the data bus is to be sent to the data bus.

The hold bit holding circuit 11 maintains a state in which the measurement of the period of the wheel speed pulse is completed by the counters 8-1 to 8-N.

The CPU 12 scans the hold bit holding circuit 11 and reads, via the multiplexer 1o, the values stored in the buffers 9-1 to 9-N corresponding to the hold bits set. RESET
It sends a signal to reset the 7-digit detection circuit 7-1, the counter 8-1, etc. The hold bit is set by resetting the edge detection circuit 7-1. Then, a control signal is sent to an anti-skid brake control section (not shown) to perform anti-skid brake control that is optimal for the read wheel speed.

Next, the operation will be explained in detail using the waveform diagram shown in FIG.

Waveform (2) in FIG. 3 is a waveform obtained by shaping the wheel speed pulse generated by the wheel speed sensor 1-1 by the waveform shaping circuit 6-1.

Is the waveform ■ an edge detection circuit? -1, and corresponds to one cycle of the wheel speed pulse.

Waveform ■ is a clock waveform. By counting this clock, the time of one cycle of the wheel speed pulse is measured.

Waveform (2) is a manual waveform for counter 8-1.

The waveform (2) is a waveform obtained by counting the waveform (2) by the counter 8-1.

The waveform ■ is the edge detection circuit 7-1 and the counter 8-1.
This is the waveform that resets the .

Waveform (2) is a waveform held by the hold bit holding circuit 11. When a hold bit is set in this hold bit holding circuit 11.

The CPU that was sequentially scanning the hold bit holding circuit 11
12 reads the wheel speed data stored in the buffers 9-1 to 9-N assigned to you.

Next, a waveform ① (reset signal) is sent out to reset the wheel speed and start measuring the wheel speed again.

As explained above, when wheel speed measurement is completed by each counter 8-1 to 8-N.

Since a hold bit is set in the hold bit holding circuit 11, the CPU 12 scans the hold bit holding circuit 11 at an arbitrary timing.

Buffer corresponding to the set hold bit 9-
It becomes possible to sequentially read wheel speed data from 1 to 9-N and perform anti-skid brake control.

〔Effect of the invention〕

As explained above, according to the present invention, the period of the pulse signal generated corresponding to the rotational speed of each wheel is measured by the pulse period counting circuit, and the state when this measurement is completed is stored in the hold bit holding circuit. By displaying the CPU
This is because the speed of each wheel can be sequentially detected asynchronously with the pulse signal corresponding to the rotational speed and the necessary control can be performed.

Stable anti-skid brake control can be performed even at high speeds and low speeds.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the basic configuration of the present invention, FIG. 2 is a diagram showing the configuration of one embodiment of the present invention, and FIG. 3 is a diagram showing operating waveforms of the configuration shown in FIG. In the figure, l-1 to 1-N are wheel speed sensors, 2-1 to 2-N are pulse period counting circuits, 3-1 to 3-N are hold bit holding circuits, 4 is a control unit, and 5-1 to 5
-N represents an anti-skinned brake control section. Patent Applicant: Fujitsu Limited (1 other person) Representative Patent Attorney: Fumihiro Hase (1 other person) 4♂e1 Thick Burial Contract Structure A゛ No. 1 Figure 21 shows the moving body performance mouth shown in Figure 3.

Claims (1)

[Claims] An anti-skid brake control device that performs brake control corresponding to the speed of each wheel includes a wheel speed sensor (1) that generates a pulse signal having a period corresponding to the rotational speed of each wheel; A pulse period counting circuit (2) that measures the period of the pulse signal output from each wheel sensor (1), and a state in which the measurement of the period of the pulse signal is completed by each pulse period counting circuit (2) is held. The pulse period counting circuit (3) scans the hold bits held in the hold bit holding circuit (3) and displays a pulse period counting circuit (3) when the hold state is displayed. After reading the value measured by step 2), the pulse period counting circuit (2) is reset to detect the speed of each wheel, and apply brake control to each wheel in accordance with the detected wheel speed. An anti-skid brake control device characterized in that it is configured to control an anti-skid brake.