JPH11344561A - Method and device for measuring traveling speed making use of microwave - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device capable of continuously obtaining the information related to the correct traveling speed and measuring the information by a cost- favorable means making use of the Doppler effect of the microwave irrespective of the characteristic of the mechanism of a moving body with the device mounted thereon. SOLUTION: The microwave is transmitted with an angle downwardly in the traveling direction from an upper position of a traveling surface of a moving body to the traveling surface, the microwave reflected by the traveling surface is received, the frequency component (D) of <= several kHz dependent on the Doppler effect of the received microwave and the microwave frequency components (J; U) of >= several MHz mixed during the reception are captured by a horn(H) for the same microwave reception, the data of these frequency components (D; J; U) are separated into the part of <= several kHz and the part of >= several MHz, the frequency component (D) of <= several kHz is used for the data for measuring the speed, and the microwave frequency components (J; U) of >= several MHz are used for the signal to measure the presence/absence of the mixed microwave.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring a moving speed of a moving object more accurately without being affected by the structural characteristics of the moving object to be mounted, and a time required for measuring the speed. The first object is to shorten the time, and the second object is to use the above-mentioned features effectively. The second purpose is based on the characteristics of the speed measurement result.
Used as applied technology of a to d. a: Measure an accurate moving distance. b; Obtain accurate speed notification information. c: Since the speed value is obtained accurately and continuously, the other devices can be controlled sequentially using the continuous speed value. d; Using the fact that the speed is measured accurately and continuously, an accurate moving distance is calculated.

[0002]

2. Description of the Related Art For example, in the case of the first prior art in which the speed of a moving body is measured by measuring the number of revolutions of a mounted engine, the load on the engine changes due to the difference in road surface conditions of the vehicle, and the measurement result fluctuates. . Further, in a so-called hybrid type vehicle formed by fusing an internal combustion engine and an electric motor, measurement cannot be performed. For example, even in a standard speed measuring means of an automobile which measures the vehicle speed from the rotation speed of an axle, an error in speed measurement occurs due to a difference in tire pressure. There is no speed measurement means that can flexibly cope with differences in running surfaces such as roadways, on snow, on ice, and on water.

[0003]

As described above, since the moving speed is measured by a method depending on the mechanical characteristics of the mounted moving body, a speed measuring device is required for each type of the mounted moving body. Because it had to be created, it was expensive. For this reason, especially when the target mounted mobile object is unspecified, a method such as taking an average value of the characteristics of the target mobile object is used. Had occurred. Also, since some information must be transmitted to the mobile object, an electrical connection is required at the time of mounting, and the user is burdened with the connection. Furthermore, it is difficult to measure the moving speed by mounting the target mounted mobile body on a mobile body such as on snow, ice, or water without being limited to the vehicle.

[0004]

In the running speed measuring method according to the present invention, a microwave is transmitted at an angle from a position above a running surface of a moving body to a running surface toward a running surface, and the moving surface is measured. Receiving the microwave reflected from the
It is characterized in that the traveling speed of the moving body is measured from a change in the frequency of the received microwave.

[0005] The traveling speed measuring device using microwaves of the present invention transmits microwaves at an angle from the position above the traveling surface of the moving body to the traveling surface downward in the traveling direction,
Receiving the microwave reflected from the running surface, a frequency component (D) of several KHz or less depending on the Doppler effect of the received microwave, and a microwave frequency component of several MHz or more (J; U) is captured by the same microwave receiving horn (H), and these frequency component (D; J; U) data are counted.
KHz or less, separated into several MHz or more, frequency components (D) of several KHz or less are used as data for speed measurement, and further,
It is characterized in that a microwave frequency component (J; U) of several MHz or more is used as a signal for measuring the presence or absence of microwave mixing.

[0006]

Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram schematically illustrating a state of measuring a relative speed of a moving body with respect to a running surface, and a speed measuring method of the present invention will be described with reference to FIG. In the figure, reference numeral 1 denotes a moving body, and the moving direction of the moving body is as indicated by an arrow. A glass window is provided before and after the moving body in the moving direction. Inside the glass window is a horn H for transmitting and receiving microwaves
Is provided. In FIG. 1, the horn H is provided on both the front and rear sides, but either one may be used.

The horn H is provided above the traveling surface 2 of the moving body, and is angled downward in the traveling direction from the horn H toward the traveling surface 2 (for example, the angle θ formed with respect to the ground is 30 degrees). Transmit microwave (M1). This microwave (M1) hits the running surface 2 as shown, and the reflected wave is reflected on, for example, two paths M2 'and M2, and the microwave forming the reflected wave M2 returns to the horn H again. Can be received. The received microwave M2 is the same as the transmitted microwave (M1) when the moving body is stopped, and the frequency of the reflected wave M2 when traveling toward the reflection position is reduced by the Doppler effect. Higher than the wave (M1). Conversely, the frequency of the reflected wave M2 when receding toward the reflection position becomes lower than the microwave (M1) due to the Doppler effect. From such a change in frequency, the traveling speed of the moving body is
The running speed is calculated by various conventional general methods.

[0008] The one moving body and the running surface of the two can take various forms. For example, if the moving body is an automobile, the running surface corresponds to a general road, a highway, or the like. Also, the moving body can be a hull, in which case the running surface is the sea surface,
Or the surface of a river. If the moving object is a snowmobile, the running surface is the snow-covered upper surface. Further, when the moving body is an ice vehicle, the traveling surface is an ice surface.

FIG. 1 is a schematic block diagram showing an embodiment of the present invention. In the figure, a horn H for transmitting microwaves,
A reference frequency generation unit K for forming a signal transmitted from the horn H, an IF filter unit F for separating a required frequency of the microwave received by the horn H, a relatively high frequency contained in a signal input to the filter A microwave detector L for detecting the component, and a microwave speed for analyzing a relatively low frequency component contained in a signal input to the filter and counting a numerical value corresponding to the speed from the frequency component And a counter C.

Hereinafter, the configuration of the present invention will be described with reference to an example of transmission information. The horn H receives the input of 11558 MHz generated by the reference frequency generation unit K, and transmits the signal at the same frequency with directivity. For example, when the horn is installed in an ordinary passenger car, which is a standard usage environment, the horn is provided near the sun visor on the windshield, and the directional direction of microwave transmission of the horn is obliquely downward and forward. The 11558 MHz microwave transmitted in this manner is applied to the running surface S, and a very small part of the microwave returns toward the horn H.
If the mobile is stationary, this return signal is at 11558 MHz. On the other hand, when the vehicle is traveling forward, the return signal causes a Doppler effect on the road surface and shifts to a higher frequency in accordance with the relative speed. This frequency also changes depending on the angle θ (SH) formed between the running surface and the pointing direction of the horn, but is corrected by multiplying the calculation result of the microwave speed counter by a constant K corresponding to the angle θ (SH). be able to.

Next, the reflected wave from the traveling surface received by the horn H is, for example, 1155 at an unknown speed traveling forward.
An 8 MHz reflected wave is received. In addition, various microwaves existing in the outside world exist as noises for speed detection. On the other hand, when microwaves existing in the outside world are analyzed and a desired microwave is to be received, a reflected wave from the running surface becomes noise.
Therefore, as a more actual state, as shown in the drawing, as a reflected wave from the running surface, a microwave having a frequency modulated to a range of ± several KHz by Doppler to 11558 MHz,
Microwaves having a frequency of 4150 MHz or 10525 MHz exist as remarkable data in this microwave region.
Under this realistic situation, the signal received by the horn H is passed through an IF filter F in order to process it while removing noise, and a low frequency band for speed measurement (several KHz)
And a high-frequency band (thousands of MHz) for detecting microwaves existing in the outside world. As a specific example, it can be formed by combining a high-pass filter and a low-pass filter. The high frequency side that has passed through the IF filter F is further input to the microwave detection unit L. The input signal is amplified once by the high-frequency amplifier L1. Also, the local oscillator L2 generates a signal of 1022,3 MHz, which is mixed with the output signal of the high-frequency amplifier L1,
The conversion is made to a frequency conversion of around 10,7 MHz. Again, the frequency around 10,7 MHz is amplified by the IF (L3), and is passed through the gate circuit (L4) as required, thereby performing rectangular wave processing and output from the output A.

The low frequency side that has passed through the IF filter F is further input to a microwave speed counter. The input signal is shaped into a rectangular wave while being amplified by the waveform shaping circuit C1. A reference clock pulse generator C4 separately prepared generates a stable pulse having a frequency suitable for counting the speed. Next, the gate control circuit is a gate-type control circuit in which a pulse generated by the waveform shaping circuit C1 passes in a positive region of the rectangular wave shaped by the waveform shaping circuit C1, and the passed pulse is counted by the counting circuit C3. The output is counted as the output B.
An example of this counting state is shown in C2 '. The square wave shown is
One rectangular wave of the waveform after passing through the waveform shaping circuit C1 controls the gate control circuit C2 as it is, thereby passing the signal from the reference clock pulse generator C4. The passed pulses are sequentially added and digitized.

FIG. 3 shows a process of calculating the speed or distance of the moving body from the output B, and the output A using the calculated speed.
It is a block diagram which shows the display process of. First, the process up to speed calculation will be described. The output B is subjected to reciprocal processing in S1. That is, the output B has a small difference due to the Doppler effect when the moving body is at a low speed, and the output B is a rectangular wave shown in FIG.
The frequency of the square wave indicated by 2 'becomes lower. for that reason,
The pulse passing through the rectangular wave approaches the maximum value. Conversely, when the speed of the moving object increases, the Doppler effect increases, so the frequency of the difference increases, and the pulse passes through the high-frequency rectangular wave. This is because the number of pulses is reduced. Therefore, by performing the reciprocal process as shown in S1, the output B takes a value proportional to the moving speed. Next, in S2, as described above, the mounting position of the moving body is multiplied by the constant K for performing correction in accordance with the irradiation angle of the microwave toward the running surface. As described above, the correct speed S3 of the mounted moving body can be obtained from the reflected microwave. The calculation result S3 can be continuously displayed on the display device 1. By transmitting the calculation result S3 to the S10 arbitrary speed monitoring and warning device, a warning sound can be emitted from the speaker when the speed reaches a preset speed.

Distance calculation process: The speed S3 can be converted into a distance by the integration processing of S4. Furthermore, various measurement results can be calculated by combining the speed information and the distance information. Next, an example of measuring the time between certain distances will be described. The start of integration of the distance calculation integration processing unit in S4 is performed by a command signal from the timing processing unit in S5. For example, a start trigger is issued when the speed moves from 0 to plus. At the same time as the start trigger, the timer of the integrated time measuring unit S6 is started to start time measurement. Next, when the distance value by the distance calculation integration processing unit in S4 reaches a predetermined distance, a stop trigger is transmitted from the distance calculation integration processing unit in S4 to the timing processing unit S5, and the integration time measurement unit S6 Stop the integration time of. Further, the accumulated time in the accumulated time measuring unit S6 is promptly displayed on the display device 3.

Output A control in FIG. 3 As described above, the speedometer of the present invention can detect a very accurate traveling speed unlike the case of detecting a pulsating flow interlocked with a generator in a vehicle, as described above. On the other hand, the accuracy of the measured value of the measured traveling speed is reduced due to a disturbance factor of the microwave that is the same or a positive multiple that can interfere. Therefore, notifying the user that there is a possibility that the accuracy has deteriorated solves various problems beforehand. However, it is important to notify the user of this decrease in accuracy at a safe low speed, which has no significance in terms of safety, and it is important to inform that the accuracy may decrease in a higher speed state. . The above object is achieved by controlling the output A stepwise according to the traveling speed. One example is described below with reference to FIG. In the figure, an output A (L5) is input to a low-speed control circuit S7. The low-speed control circuit S7 receives the signal from the speed calculation result S3, and displays the level 1 display result on the display device 4 when the speed is 0 to 30 km / h. Next, only when the speed exceeds 30 km / h, the signal of the output A is transmitted to the next medium speed control circuit. The medium speed control circuit S8 receives the signal from the speed calculation result S3, and if the speed is 31 to 50 km / h, the level 2
Is displayed on the display device 4. Next, only when the speed exceeds 51 km / h, the signal of the output A is transmitted to the next high-speed control circuit. The high-speed control circuit S9 receives the signal from the speed calculation result S3, and when the speed is 51 km / h or more,
The display result of level 3 is displayed on the display device 4. The display device 4 may be a speaker if necessary. In this case, the levels 1, 2, and 3 can be volume levels. Further, the reception sensitivity of the microwave detection unit L can be changed instead of the display level.

In the above embodiment of the present invention, other embodiments as described below can be obtained as required. In FIG. 3, the control target corresponding to the speed is the output A, but another control target can be set as necessary. For example, the output A may be a car stereo audio output. The control target is the volume control of the car stereo, and the control condition is that the volume level of the car stereo is also increased in accordance with the speed increase in accordance with the environmental conditions in which the noise level increases as the vehicle moving speed increases in a normal vehicle. It is to control to rise. This additional embodiment is illustrated in FIG.
This will be described with reference to a part of the block diagram of FIG. First, output A
The input of the audio signal replaced with (L5) is input to the low-speed control circuit S7. The low-speed control circuit S7 receives the signal from the speed calculation result S3, and when the speed is 0 to 30 km / h, outputs the signal to the car stereo side instead of the display device 4 as the level 1 volume. I do. Next, 30km
When the speed exceeds / h, the audio signal is transmitted to the next middle speed control circuit, and the middle speed control circuit S8 inputs the signal from the speed calculation result S3, and when the speed is 31 to 50 km / h, Outputs the level 2 volume. Next, the audio signal is transmitted to the next high-speed control circuit only when the speed exceeds 51 km / h. The high-speed control circuit S9 receives the signal from the speed calculation result S3, and outputs a volume of level 3 when the speed is 51 km / h or more. In this way, the volume of the car stereo can be controlled according to the speed.

Although the input and output described above for the other embodiment of FIG. 3 are described for input and output of audio signals of a car stereo, the relationship between the input and output is controlled by the air volume control and the temperature setting control of the air conditioner. The present invention can be used for arbitrary control such as control for turning off a headlight, and control for stopping a wiper at a high speed and moving at a middle and low speed.

[0018]

The traveling speed measuring method using the microwave according to the present invention transmits the microwave at an angle downward from the position above the traveling surface of the moving body toward the traveling surface toward the traveling surface. Receiving the microwave reflected from the
Since the traveling speed of the moving object is measured from the change in the frequency of the received microwave, it does not depend on the mechanical characteristics of the mounted moving object, so only the angle at which the microwave is transmitted with respect to the traveling surface is used. It can be used irrespective of the type of the target moving object to be mounted simply by installing the same. In addition, since the power supply of this measuring device is composed of a solar battery or a normal battery, connection with a moving object is not required at all, and an accurate traveling speed can be obtained. No
Very convenient devices can be made. In addition, since it does not depend on the mechanical characteristics of the target moving object to be mounted, the target mounted moving object does not need to be limited to the vehicle, and is mounted on a moving object such as on snow, ice, or water, and the moving speed is measured. It became possible freely.

In the traveling speed measuring device utilizing microwaves according to the present invention, microwaves are transmitted at an angle from the position above the traveling surface of the moving body toward the traveling surface and downward in the traveling direction, and reflected from the traveling surface. Received microwaves, the number depending on the Doppler effect of the received microwaves
Frequency component (D) below KHz and several MHz mixed at the same reception
The above microwave frequency components (J; U) are captured by the same microwave receiving horn (H), and these frequency component (D; J; U) data are separated into several KHz or less and several MHz or more. Using frequency components (D) of several KHz or less as data for speed measurement,
Furthermore, since it is characterized by using a microwave frequency component of several MHz or more as a signal for measuring the presence or absence of microwave mixing, by one horn (H), the microwave reflected from the running surface and the In addition, the same microwave receiving horn (H) can catch the microwave frequency component of several MHz or more mixed at the same receiving time. As a result, it is not necessary to prepare a plurality of types of horns, and when using a plurality of horns, there is a possibility that a plurality of reference frequencies may be provided, in which case the plurality of reference frequencies may interfere with each other. Cause this interference to the received microwave, and as a result,
It is possible to avoid a phenomenon that causes a decrease in the reception capability.

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating a state in which a relative speed of a moving body to a traveling surface is measured.

FIG. 2 is a schematic block diagram showing one embodiment of the present invention.

FIG. 3 is a block diagram illustrating a process of calculating a speed or a distance of a moving object from an output B and a process of displaying an output A using the calculated speed.

[Explanation of symbols]

In FIG. 1, 1 ... moving body, 2 ... running surface, M1 ... transmitting microwave, M2
Reflected wave, H: Horn, F: IF filter, L: Microwave detector, C: Microwave speed counter.

Claims (2)

[Claims] 1. A microwave is transmitted at an angle downward in the traveling direction from a position above a traveling surface of a moving body toward the traveling surface, and the microwave reflected from the traveling surface is received.
A traveling speed measurement method using a microwave, wherein the traveling speed of a moving object is measured from a change in the frequency of a received microwave. 2. A microwave is transmitted at an angle downward in the traveling direction from a position above the traveling surface of the moving body toward the traveling surface, and the microwave reflected from the traveling surface is received;
Several KHz depending on the Doppler effect of the received microwave
The following frequency components (D) and the microwave frequency components (J; U) of several MHz or more mixed during the same reception are captured by the same horn for microwave reception (H), and these frequency components (D; J; U) Separate the data into several KHz or less and several MHz or more and use the frequency component (D) of several KHz or less as data for speed measurement, and further, the microwave frequency component of several MHz or more (J; U ) Is used as a signal for measuring the presence or absence of microwave mixing, and a traveling speed measuring device using microwaves.