JPH0625664B2 - Method and apparatus for detecting snow accretion thickness of vehicle - Google Patents

Description

The present invention relates to a snow accretion thickness detection method and device for a vehicle.

(B) Conventional technology When a vehicle travels on a rail in a snowy state, the wind pressure causes the snow to fly up, and the soared snow adheres to the wall-like part under the floor of the vehicle body and causes snow accretion. Since it is necessary to control the speed of the vehicle depending on the snow accretion state, it is necessary to measure the snow accretion thickness. The snow accretion thickness is visually measured by a worker using a ruler when the vehicle stops at a station.

(C) Problems to be Solved by the Invention However, with the method of measuring when the vehicle is stopped as described above, it is not possible to know the change in the snow accretion thickness during traveling, and it is possible to travel to the next stop station. When the time is long, the snow accretion thickness may exceed the allowable range. An object of the present invention is to make it possible to automatically measure the snow accretion thickness even while traveling.

(D) Means for Solving the Problems The present invention solves the above problems by detecting the snow accretion thickness using an ultrasonic sensor.

That is, the method for detecting the snow accretion thickness of a vehicle according to the present invention is a method in which a plurality of downward ultrasonic sensors arranged below the floor of the vehicle body are positioned above the rail and are parallel to the rail. The ultrasonic wave is transmitted toward and the reflected wave is received, and only the part corresponding to the reflected wave from the rail is taken out of the output voltage due to the received reflected wave, and there is no obstacle in the extracted output voltage and in the middle. Compare with a reference voltage that is smaller than the voltage that should be obtained by the reflected wave reflected from the rail in the state by a predetermined ratio,
The thickness of snow accretion is detected from the position of the ultrasonic sensor whose output voltage is smaller than the reference voltage.

Further, a snow accretion thickness detecting apparatus for a vehicle according to the present invention for carrying out the above method includes a sensor unit (22) mounted under the floor of a vehicle body (16) and a signal processing unit (26) to which a signal from the sensor unit is input. ) And an indicator (28) operated by an output signal from the signal processing unit, and the sensor unit is arranged above the rail (10) on the front side of the wall portion (20). The sensor unit has a plurality of ultrasonic sensors (24) arranged at a predetermined interval in parallel with the rail. The ultrasonic sensor transmits and receives ultrasonic waves and outputs a voltage signal according to the received reflected waves. The signal processing unit can output to the signal processing unit, and the signal processing unit includes an oscillator (30) for oscillating the ultrasonic sensor at a resonance frequency and a rail among output voltages from the ultrasonic sensors. A timing circuit (36) and a sample and hold circuit (42) for extracting only the portion corresponding to the emission wave of the output signal, and comparing the extracted output voltage with a predetermined reference voltage to obtain an output voltage smaller than the reference voltage. And a comparison calculation circuit (44) for outputting a signal for operating the display so as to identify the sound wave sensor and display the snow accretion thickness based on the determination result. The reference numerals in parentheses indicate the corresponding members in the embodiments described later.

Instead of using a plurality of ultrasonic sensors, one ultrasonic sensor can be moved to detect the snow accretion thickness.

(E) Action The ultrasonic sensor sends a harmonic wave to the rail,
The reflected wave of this is received. A voltage signal is obtained corresponding to the reflected wave received by the ultrasonic sensor. When the reflected wave reflected from the rail is received without being disturbed by snowfall, a predetermined high output voltage is obtained.
On the other hand, when the ultrasonic waves transmitted from the ultrasonic sensor are disturbed by snowfall, the reflected waves reflected from the rails decrease and the output voltage decreases. The snow accretion thickness can be detected from the position of the ultrasonic sensor whose output voltage has decreased to a value smaller than the predetermined reference voltage.

(F) Example An example of the present invention is shown in FIGS.

As shown in FIG. 1, wheels 12 that rotate on rails 10
The carriage 14 is supported by the carriage 14, and the vehicle body 16 is supported by the carriage 14. A box 18 is fixed below the floor of the vehicle body 16, and a wall upper portion 20 is formed on the front side in the vehicle traveling direction. A sensor unit 22 is provided on the front side of the underfloor wall 20 of the vehicle body 16. Sensor unit 2
2 is arranged above the rail 10 and has a plurality of ultrasonic sensors 24 arranged in parallel with the rail 10 at predetermined intervals. The signal from the sensor unit 22 is input to the signal processing unit 26. The signal processing unit 26 outputs a signal to activate the display 28.

FIG. 2 shows the structure of the signal processing unit 26. The signal processing unit 26 includes an oscillator 30, a changeover switch 32, a changeover switch 34, a timing circuit 36, an amplification circuit 38, a rectification circuit 40, a sample hold circuit 42, and a comparison operation circuit 44. The oscillator 30 is an ultrasonic sensor 24.
It can oscillate at the resonance frequency of. The timing circuit 36 outputs a signal at a predetermined interval, and the changeover switch 32, the changeover switch 34, and the sample hold circuit 42 can be sequentially changed over. The plurality of single switches constituting the changeover switch 32 and the changeover switch 34 are the ultrasonic sensors 2 respectively.
It is connected with 4. The output signal from the ultrasonic sensor 24 is amplified by the amplifier circuit 38 and further rectified by the rectifier circuit 40. The signal from the rectifier circuit 40 is supplied to the timing circuit 3
It is stored in the sample hold circuit 42 having a gate which is opened and closed by the signal from 6. The output voltage of the reflected wave stored in the sample hold circuit 42 is compared with the reference voltage in the comparison operation circuit 44, and a signal for operating the display 28 is output based on this.

Next, the operation of this embodiment will be described. The oscillator 30 of the signal processing unit 26 constantly oscillates at a predetermined frequency, and the changeover switch 32 causes the plurality of ultrasonic sensors 24
Are made conductive for a predetermined time. The operation of the changeover switch 32 is controlled by a signal from the timing circuit 36. One ultrasonic sensor 24 is, for example, the third
As shown in the figure, ultrasonic waves are transmitted for a fixed time t ₁ . The transmitted ultrasonic wave 46 basically hits the rail 10 and is reflected as shown in FIG. However, as shown in FIG. 6, if there is snow 48 on the wall 20, it is also reflected by it and also from the ground 11 (gravel surface) on which the rail 10 is laid. The reflected wave is received by the ultrasonic sensor 24. In this case, a signal from the timing circuit 36 causes the changeover switch 34 to be conductive for the time t ₂ shown in FIG. A signal based on the reflected wave received by the ultrasonic sensor 24 is amplified by the amplification circuit 38 and then rectified by the rectification circuit 40. The voltage signal based on the reflected wave received by the ultrasonic sensor 24 is, for example, as shown in FIG. 4, but the voltage signal output from this by the action of the rectifying circuit 40 is the third signal.
It is as shown in the figure. The rectifier circuit 40
The output voltage from the device includes a reflected wave from the snow accretion 48 adhering to the wall-shaped portion 20 (a), a reflected wave from the ground 11 (c), etc. By opening the gate of the circuit 42 for t ₄ hours after t ₃ hours after the transmission of ultrasonic waves is started, only the output voltage (b) due to the reflected wave from the rail 10 can be stored in the sample hold circuit 42. it can. This is based on the fact that the distance between the ultrasonic sensor 24 and the rail 10 and the speed of the ultrasonic wave are predetermined, so that the time when the reflected wave from the rail 10 is captured by the ultrasonic sensor 24 can be predicted. ing. The voltage signal thus obtained is compared with the reference voltage in the comparison operation circuit 44. When there is no obstacle between the ultrasonic sensor 24 and the rail 10 as the reference voltage (state shown in FIG. 5)
The value of 50% of the voltage obtained in is set. Most of the ultrasonic waves from the first and second ultrasonic sensors 24, which are taught from the wall-shaped portion 20 side in FIG. 1, are reflected by the snow 48, so the output voltage becomes a very small value. , Below the reference voltage (off). On the other hand, from the wall-shaped portion 20 to the third ultrasonic sensor 24, as shown in FIG. 6, about half of the ultrasonic waves are obstructed by the snow accretion 48, so that the output voltage becomes a value substantially equal to the reference voltage. If the amount of snow accretion 48 slightly increases from the state shown in FIG.
The th ultrasonic sensor 24 is also turned off. The snow accretion thickness is displayed on the display 28 based on the judgment up to what number the ultrasonic sensor 24 is off. Thereby, the snow accretion thickness can always be detected automatically.

Although the sensor unit 22 has a plurality of ultrasonic sensors 24 in this embodiment, one ultrasonic sensor 24 is provided in the sensor unit 22 and the reflected wave is generated by moving the ultrasonic sensor 24 by the reciprocating mechanism. It is also possible to find the position where the voltage is equal to or lower than the reference voltage.

(G) Effect of the Invention As described above, according to the present invention, the snow accretion thickness is detected by using the ultrasonic sensor. Therefore, the snow accretion thickness can be detected on the vehicle while traveling. It becomes possible to regulate the speed appropriately when the snow accretion amount increases during traveling, and it is unnecessary to measure the snow accretion thickness using a ruler when the vehicle is stopped. Become.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing a signal processing unit, and FIG. 3 is a diagram showing ultrasonic wave transmission, reception, gate opening / closing, and output voltage with the horizontal axis representing time. , 4th
The figure shows the voltage signal obtained by the ultrasonic sensor, FIG. 5 shows the ultrasonic wave transmission state in the absence of snow, and FIG. 6 shows the ultrasonic wave transmission state in the presence of snow. It is a figure. 10 ... rails, 12 ... wheels, 16 ... body, 20 ...
... Wall-shaped part, 22 ... Sensor unit, 24 ... Ultrasonic sensor, 26 ... Signal processing unit, 28 ... Indicator, 30 ... Oscillator, 32 ... Changeover switch, 34 ...
Changeover switch, 36 ... Timing circuit, 42 ... Sample and hold circuit, 44 ... Comparison calculation circuit, 46 ... Ultrasonic wave, 48 ... Snow accretion.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Tokuji Hayashi 1321 Yoshioka, Yotsukaido, Chiba Prefecture Nihon Steel Works, Ltd. (72) Inventor Toshio Inami 1321 Yoshioka, Yotsukaido, Chiba Nihon Steel Works, Ltd. (72) Inventor Toyohiko Yamamoto 1321 Yoshioka, Yotsukaido, Chiba Prefecture Nihon Steel Works Co., Ltd. (56) Reference JP-A-58-28608 (JP, A) JP-A-62-185182 (JP, A) Actual development Sho-62-53382 (JP, U)

Claims (3)

[Claims] Claim: What is claimed is: 1. A thickness dimension from a wall-shaped portion of snow adhering to a wall-shaped portion which is provided on a rear side of a wheel of a vehicle traveling on a rail and which extends vertically or substantially vertically downward from a vehicle floor. In the method for detecting the snow accretion thickness of a vehicle to be measured, a plurality of downward ultrasonic sensors located above the rail and arranged under the floor of the vehicle body at a predetermined interval so as to be parallel to the rail are used to move toward the rail. Sends out ultrasonic waves and receives reflected waves, takes out only the part of the output voltage due to the received reflected waves that corresponds to the reflected waves from the rail, and removes the above-mentioned output voltage and the rail with no obstacles in the middle. Compared with a reference voltage that is smaller than the voltage that should be obtained by the reflected wave reflected from
A snow accretion thickness detection method for a vehicle, comprising detecting the snow accretion thickness from a position of an ultrasonic sensor whose output voltage is smaller than a reference voltage. 2. A thickness dimension from a wall-shaped portion of snow adhering to a wall-shaped portion provided on the rear side of a wheel of a vehicle traveling on a rail and extending vertically or substantially vertically downward from the vehicle floor. In a snow accretion thickness detection device for a vehicle to be measured, a sensor unit mounted under the floor of the vehicle body, a signal processing unit to which a signal from the sensor unit is input,
An indicator operated by an output signal from the signal processing unit, and the sensor unit is disposed above the rail on the front side of the wall-shaped portion, and the sensor units are arranged at predetermined intervals in parallel with the rail. The ultrasonic sensor is capable of transmitting and receiving ultrasonic waves and outputting a voltage signal to the signal processing unit according to the received reflected wave. An oscillator that oscillates the sound wave sensor at the resonance frequency, a timing circuit and a sample hold circuit for extracting only the portion of the output voltage from each ultrasonic sensor that corresponds to the reflected wave from the rail, and the extracted output voltage The ultrasonic sensor that has an output voltage smaller than the reference voltage is compared with the reference voltage of and the snow accretion thickness is displayed based on this determination result. Snow accretion thickness detecting apparatus for a vehicle, characterized in that it comprises a comparison operation circuit for outputting a signal for actuating the indicator on so that, the. 3. A thickness dimension from a wall-shaped portion of snow adhering to a wall-shaped portion provided on the rear side of a wheel of a vehicle traveling on a rail and extending vertically or substantially vertically downward from the vehicle floor. In the method of detecting the snow accretion thickness of a vehicle to be measured, an ultrasonic sensor is installed under the floor of the vehicle body so as to reciprocate above the rail in parallel with it, and an ultrasonic wave is transmitted toward the rail and a reflected wave is received. However, only the portion of the output voltage due to the received reflected wave that corresponds to the reflected wave from the rail should be extracted, and it should be obtained by the extracted output voltage and the reflected wave reflected from the rail without any obstacles in the way. Compared with a reference voltage that is smaller than the voltage by a predetermined ratio, and detecting the snow thickness from the position of the ultrasonic sensor when the output voltage decreases below the reference voltage. Detection method .