JPS6277803A - Speed detecting device for vehicle - Google Patents

Abstract

PURPOSE:To enable the vehicle speed to correctly detect from low speed to high speed regardless of the slip or skid of the wheels by providing plural speed detecting means. CONSTITUTION:When the slip or skid of wheels is not generated, a signal which integrated the output of an acceleration detector or an integration gyro 9 to detect the adjustable speeds in the forward and backward directions of a vehicle is outputted as a speed signal 21 through an analog switch 16, while the slip or skid of the wheels is judged on the basis of the rotating pulses of motors 4a and 4b, which are outputted from proximity switches or rotary encoders 6a and 6b, and when the slip or skid is generated, the analog switch 16 is turned off an an analog switch 15 is turned on. Hereby a signal converted the rotating pulses into F/V is outputted as the speed signal 21. If the both signals conincide with each other, the analog switch 15 is turned off and the analog switch 16 is turned on.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a speed detection device for a vehicle.

[Technical backbone of the invention and its problems] In a track-type vehicle, as shown in Figure 4, the rail 1
When the wheels 2 are rotated and run, the output of the speed generator Fs (or encoder) 5 that rotates the same number of rotations as the motor is at the other end of the motor 4 coaxial with the gear box 3 connected to the wheels 2. Detects the rotation speed of the wheel and generates speed power R5
The vehicle speed is detected by the voltage (or the number of encoder pulses).

However, especially when the speed of a high-speed vehicle is increased to 2001 m
When the vehicle starts traveling at speeds exceeding /h, there is a risk that the wheels 2 may slip between them and the rail 1, especially when decelerating.
The disadvantage is that accurate speed cannot be obtained.

[Objective of the Invention 1 The present invention has been made based on the above-mentioned circumstances, and its object is to provide a speed detection device for a vehicle that can accurately detect vehicle speed from low speeds to high speeds without regard to wheel slippage. Our goal is to provide the following.

[Summary of the Invention] In order to achieve the above object, the speed detection device for a vehicle according to the present invention is characterized in that it is rare for wheels driven by electric motors to simultaneously spin or skid, and that it is difficult for the wheels to spin or skid at the same time.
Focusing on the fact that when a skid occurs, the color of the rotation of electric machine A changes beyond a specified value, the first speed detection means detects the rotation speed of wheel drive type A using a plurality of proximity switches or encoders. The second speed detecting means detects the acceleration/deceleration of the vehicle in the longitudinal and reverse directions using an acceleration detector or an integrating gyro, and integrates it using an integrator, as well as a pulse generator, voltage memory circuit, and addition. The output of the first speed detecting means is stored in the voltage memory circuit by the pulse output from the pulse generator at regular intervals, and the integrator is initialized to output the integrator. and the output of the voltage memory circuit are added by the adding circuit to detect the vehicle speed, and depending on the wheel slipping/skidding detector, wheel slipping or skidding is detected based on the fact that there is no difference in the output pulses of the plurality of proximity switches. At the same time, when the amount of change per unit time in the number of output pulses of each of the plurality of proximity switches does not exceed the specified acceleration/deceleration of the vehicle, wheel slipping and skidding are detected. The output is a detection output, and the output of the first speed detection means is used as a detection output only when a pulse generated by the pulse generator at a certain time interval is generated;
When a slip and skid occurs due to the output of the slip and skid detector, the storage operation of the voltage memory circuit and the integration operation of the integrator are stopped, and the output of the first speed detection means and the output of the second speed detection means are stopped. The two outputs are compared, and when the two outputs are equal, the slipping/sliding detector is reset.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to FIG. 1 and FIG. 2.

FIG. 1 is a block diagram of the apparatus of this embodiment. FIG. 2 is a timing chart of the same embodiment. 4a, 4b are motors (electric 1m>, 6a, 6b are proximity switches (photoelectric sensors) or encoders, 7a.

7b is a waveform shaping circuit, 8 is a slipping/skidding detector composed of a microcomputer, etc., 9 is an accelerometer or an integrating gyro, 10 is an integrator, 11 is an analog memory circuit, 12 is an addition circuit,
138 is a summing point, 13b is an amplifier, 14LtF/V
Conversion circuit, 15.161L7 analog switch, 17 is a pulse generator, 18 is an AND circuit, 19 is an inverter, 2
0 is a voltage comparison circuit, and 21 is a speed detection output.

Figure 2 <a) is the pulse generator output waveform, Figure 2 (b)
is the output waveform of the slip/slide detector, and FIG. 2(C) is the output waveform of the AND circuit.

Next, the operation of the first embodiment configured as described above will be explained. That is, the motor 4 is connected to a non-rotating wheel.
The rotational speed of a is detected by a proximity switch (photoelectric sensor) or a rotary encoder 6a, and the waveform is shaped by a waveform shaping circuit 7a so that the waveform is not distorted. Similarly, the rotation speed of the motor 4b connected to the other axle can be controlled by the proximity switch (
The signal is detected by a photoelectric sensor) or a rotary encoder 6b, and the waveform is shaped by a waveform shaping circuit 7b so that the waveform is not distorted.

In this embodiment, the number of rotations of two motors 4a and 4b is detected, but the number of rotations of two or more motors may be detected.

In this case, as the number of sensors increases, the cost increases, so it is effective to provide the motors connected to the wheels in contact with each of the two rails. )8, and here, the rotation of the two motors 4a, 4b within a unit time is within the specified value, or the amount of rotation change of each motor 4a, 4b exceeds the maximum value of acceleration/deceleration of the vehicle. This detects whether the level is over, and is normally at the H level, but changes to the L level when a skidding occurs.

9 is a speedometer or an integral gyro, which detects acceleration/deceleration of the vehicle in the longitudinal direction. This output is integrated by an integrator 10 to detect the speed.

14 is an F/V converter, which converts the output of the waveform shaping circuit 7a into an analog value to detect the speed. If the speed obtained by using the integrator 10 from the output of the accelerometer or the integrating gyro 9 is measured for a long time, an integration error will be added due to temperature drift, etc., and a difference will occur between the actual vehicle speeds. Furthermore, in order to achieve a configuration that can suppress cost increases: it is necessary to initialize (reset) the integrator 10 at regular intervals to the extent that the f4 difference does not cause any problems. For this purpose, a pulse generator 17 is provided to generate pulses at regular intervals (from several seconds to one minute), and these pulses cause the F/'V converter 1 to
4 is stored in the voltage memory circuit 11. Furthermore, the integrator 10 is configured so that the initialization output is zero when this output pulse is generated.

The output of the voltage memory circuit 11 and the output of the integrator 1o are added at a summing point 13a of an adder circuit 12, amplified by an amplifier 13b, and the speed is output. Therefore, the integrator 10 detects the speed from initialization until the output of the next pulse generator 17 is generated, and always uses the voltage memory circuit 11 to detect the speed of the pulse generator 17.
/V converter 14 output. As a result, an accurate output is always detected as the output of the amplifier 13b.

The output of the F/V conversion circuit 14 and the output of the amplifier 13b should be basically the same unless the wheels spin or skid. Therefore, the voltage comparator circuit 20 which detects whether the respective outputs are the same is used to generate an output when both outputs are the same, and the slipping/skidding detector 8 is reset with this output.

When no slipping or skidding occurs, that is, when the output of the slipping and skidding detector 8 is at H level, the integrator 10 and analog memory circuit 14d are calibrated by the output of the pulse generator 17, and the output of the amplifier 13b is stabilized during this calibration. Therefore, 1 analog switch 16 is always on and 15 is off,
The analog switch 16 is turned off and the analog switch 15 is turned on only when a pulse is generated, and the F,/V converter 14
The output is used as the vehicle speed detection output 21.

Furthermore, when slipping or skidding occurs and the output of the slipping/skidding detector 8 is at L level until it is reset, the output of the pulse generator 17 is applied to the integrator 10 and the analog memory circuit 11 by the AND circuit 18. The structure is such that the vehicle speed can be accurately detected even when slipping or skidding occurs.

According to this embodiment as described above, the following effects are achieved. That is, by calibrating the detector that detects acceleration in the front and back directions at regular intervals using a separate speed detector, and stopping this calibration only when a slip or one run occurs,
Accurate and inexpensive vehicle speed measurement, stability while driving,
Can improve reliability.

In particular, there have traditionally been various methods for non-contact speedometers, such as the Doppler method, but these have drawbacks such as being expensive, weak in vibration resistance, and lacking in long-term reliability. The value of the device of this embodiment is great.

Next, another embodiment of the above embodiment will be described with reference to FIG. 3, in which the same parts as in FIG. 1 are given the same reference numerals. In Fig. 3, 26.27 is a programmable counter, 25 is an amplifier, 28 is an A/D converter, 29 is a CPU (microprocessor), 30 is a clock generator, and 31 is a RAM.
, 32 is a ROM, 33 is a D/A converter, and 34 is a waveform shaping circuit.

In this embodiment, the analog circuit shown in FIG. 1 is constructed by a microcomputer, and its operation is as follows. That is, the number of revolutions of each motor 4a, 4b is measured by the programmable counter 26, 27, and the number of revolutions of each motor is calculated by the CPU based on the number of pulses per intermediate time.
29. Slippage and skidding are detected based on whether these two count values match and whether the number of revolutions per unit time does not exceed the maximum acceleration/deceleration of the vehicle.

The output of the accelerometer or integrating gyro 9 is amplified by an amplifier 25, converted into a digital value by an A/D converter 28, and integral measurement is performed by a CPU 29. This integral measurement value is calibrated at regular intervals using the measurement values of the rotational speeds of the respective motors 4a and 4b, and the CPU 29 outputs the speed as a digital value.

The D/A converter 33 converts it into an analog value, and the waveform shaping circuit 34 performs impedance matching to provide the speed detection output 21. When this integration, slipping, or sliding is detected, the above-mentioned calibration at fixed time intervals is stopped.

In vehicles, microcomputers are also used for controlling electric motors, etc., and this embodiment can be said to have a configuration in which the above-mentioned additional circuits are added to a microcomputer, and can be configured at a very low cost. It has great value in that it can be done.

[Effect of the invention 1] As detailed above, according to the present invention, it is rare for the wheels driven by electric motors to simultaneously spin or skid, and that when the wheels spin or skid, is electric
Focusing on the fact that the rotational speed of the 7In changes more than a specified value, the first speed detection means detects the rotational speed of the wheel drive electric motor using a plurality of proximity switches or encoders to detect the vehicle speed, and the second Depending on the speed detection means, an acceleration detector or an integrating gyro may be used to detect acceleration/deceleration of the vehicle in the longitudinal and reverse directions, and an integrator may be used to integrate the detected acceleration and deceleration. The output of the first speed detection means is stored in the voltage memory circuit by the output pulses at regular intervals, and the integrator is initialized so that the output of the integrator and the output of the voltage memory circuit are stored in the voltage memory circuit. The vehicle speed is detected by the addition output added by the adding circuit, and the wheel slipping and skidding is detected by the wheel slipping and skidding detector based on the fact that there is no difference in the output pulses of the proximity switches mentioned above, and the output of the small number of proximity switches mentioned above. Wheel slipping and skidding are detected when the amount of change in each unit time of the number of pulses is not greater than a specified acceleration/deceleration of the vehicle, and the output of the second speed detection means is normally used as the detection output, and the pulse transmitter The output of the first speed detecting means is used as a detection output only when a pulse is generated at regular intervals, and when a slip and skid occurs according to the output of the slip and skid detector, the memory operation of the voltage memory circuit is performed. The integrating operation of the integrator is stopped, and the output of the first speed detector Q and the output of the second speed detecting means are compared, and if the two river forces are equal, the slipping/sliding detector is reset. Therefore, it is possible to provide a speed detection device for a vehicle that can accurately detect medium speeds from low speeds to high speeds without regard to wheel slippage or skidding.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a timing chart explaining the operation of the same embodiment, FIG. 3 is a diagram showing another embodiment of the present invention, and FIG. 4 is a vehicle It is a diagram showing a drive system. DESCRIPTION OF SYMBOLS 1...Rail, 2...Wheel, 3...Gear box, 4...Motor, 5...Speed generator, 4a, 4b.
...Motor, 5a, 5b...Proximity switch or encoder, 7a. 7b...Waveform shaping circuit, 8...Slip and skid detector,
9... Accelerometer or integrating gyro, 10... Integrator, 11... Analog memory circuit, 12... Addition circuit, 14... F/V conversion circuit, 15.16... Analog switch , 17... Pulse generator, 20... Voltage comparator circuit, 21... Speed detection output, 25... Amplifier, 26° 27... Programmable counter, 28...
...A, /D conversion circuit, 29...CPU (microprocessor), 30...oscillator, 31...RA
M, 32...ROM, 33...D/A conversion circuit, 3
4... Waveform shaping circuit. Figure 1 Figure 2

Claims (1)

[Claims] (1) A first speed detection means that detects the vehicle speed by detecting the rotation speed of the wheel drive electric motor using a plurality of proximity switches or encoders, and detects the acceleration/deceleration of the vehicle in the longitudinal and reverse directions using an acceleration detector or an integrating gyro. The output of the first speed detecting means is integrated by an integrator, and also includes a pulse generator, a voltage memory circuit, and an adder circuit, and the output of the first speed detecting means is stored in the voltage memory by the pulse output at fixed time intervals output from the pulse generator. A second circuit that detects the vehicle speed based on the added output obtained by storing the integrator in the circuit and initializing the integrator and adding the output of the integrator and the output of the voltage memory circuit by the adding circuit.
Since there is no difference between the output pulses of the speed detection means and the plurality of proximity switches, wheel slipping and skidding are detected, and the amount of change per unit time in the number of output pulses of the plurality of proximity switches of the vehicle is detected. A slip and skid detector detects wheel slipping and skidding when the acceleration/deceleration is less than a specified acceleration/deceleration, and the output of the second speed detection means is normally used as the detection output, and the pulses generated by the pulse transmitter at regular intervals are used as detection outputs. The output of the first speed detecting means is used as a detection output only when the slipping and skidding occurs, and when the slipping and skidding occurs according to the output of the slipping and skidding detector, the storage operation of the voltage memory circuit and the integrating operation of the integrator are stopped. A speed detection device for a vehicle, comprising: determination means for comparing the output of the first speed detection means and the output of the second speed detection means, and resetting the slipping and skidding detector when the two outputs are equal. .