KR101061588B1 - Apparatus and method for estimating car speed using laser - Google Patents

Abstract

The present invention includes a transmitter for aiming and firing a laser signal on a moving object for distance measurement, a receiver for receiving the laser signal reflected back to the moving object, and a firing point of the laser signal and a return point reflected back. A speed measuring device for a vehicle using a laser including a timer for measuring a time difference, and a controller for analyzing the time difference to extract moving distance data of a moving object and finally determining the speed of the moving object. And a random number generator, wherein the controller calculates an irregular laser firing point using the random number output from the random number generator, and controls the transmitter to fire the laser at the calculated firing point.

Description

Apparatus and Method for Estimating Car Speed using Laser}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for speeding a vehicle, particularly to an apparatus and method for detecting a vehicle speed using a laser.

In general, in order to ensure traffic safety by controlling speeding vehicles on the road, an unmanned speed camera is installed along with a device that detects the speed of the vehicle, and a license plate is imposed for a vehicle that violates the specified speed by photographing a license plate.

Non-contact speed measurement device using a laser signal is widely used as a means for detecting the driving speed of the vehicle, which detects the firing time of the laser firing and the returning point of the returning reflected back to the driving vehicle. The speed of the vehicle can be detected by calculating the time between the viewpoints.

On the other hand, in order to avoid such an overspeed of the vehicle has been developed a laser jammer (Laser Jammer) for disturbing the laser signal of the vehicle speed sensing device.

As a method of signal disturbance of such a laser disturbance device, in the past, a method of disturbing a feedback signal of a signal emitted from a speed sensor by generating a very strong signal has been frequently used. By the way, this requires a large amount of energy and is rarely used at present because of the disadvantage that a strong laser signal is very harmful to the body.

As another disturbing method, a method of generating an irregular signal and disturbing a feedback signal of a speed sensor has been developed. However, this has the advantage that it is easy to implement, but the disadvantage is that the disturbance effect is not large.

Therefore, in recent years, an intelligent laser disturbance device composed of a laser transmitter, a laser receiver, and a timer, similar to a vehicle speed sensing device, has become popular. In order to detect the laser signal emitted from the laser speed measurement device, the laser receiver of the intelligent laser disturbance device continuously monitors the laser signal and detects the vehicle speed detection device as the regularity of the signal is found. Then, the laser transmitter of the intelligent laser disturbance device generates a disturbance signal and disturbs the feedback signal returned to the vehicle speed sensing device.

Although it is illegal in many countries to use such laser interruption devices for speed enforcement, the prevalence and development of these devices continues to expand. Accordingly, there is a further need for a vehicle speed sensing apparatus capable of overcoming laser disturbances in various manners as described above.

The present invention provides a vehicle speed sensing apparatus that can overcome laser disturbances.

The present invention provides a vehicle speed measuring apparatus for preventing the laser disturbance device from detecting a laser signal for measuring the vehicle speed.

The present invention provides a vehicle speed measuring apparatus capable of detecting the presence of a laser disturbance device.

According to an exemplary embodiment of the present invention, a transmitter for aiming and firing a laser signal on a vehicle for distance measurement, a receiver for receiving the laser signal reflected back from the vehicle, and a return point reflected and returned from the firing point of the laser signal A random speed generating apparatus for a vehicle using a laser including a timer for measuring a time difference between viewpoints and a controller for analyzing the time difference to extract moving distance data of a moving object and finally determining the speed of the vehicle. And a random number generating unit for outputting, wherein the control unit calculates at least one irregular laser firing time point by using the random number output from the random number generating unit, and controls the transmitter to fire the laser at the calculated one or more firing time points. .

According to another preferred embodiment of the present invention, calculating a launch point of an irregular laser signal using a random number, launching a laser signal into a vehicle for speed measurement at the calculated launch point, and reflecting back to the vehicle Receiving the laser signal, measuring the time difference between the firing time of the laser signal and the return point reflected back, and analyzing the time difference to extract the moving distance data of the moving object to finalize the speed of the moving object Determining.

The present invention has the advantage that the laser signal for measuring the vehicle speed can be launched at an irregular time point, so that the laser disturbance device cannot detect the laser speed measurement device.

In addition, the present invention has the advantage that can detect the presence of the laser disturbance device from the signal received by firing a regular laser.

1 is an internal configuration diagram of a vehicle speed sensing apparatus according to a preferred embodiment of the present invention.
2 is a diagram for representing a laser signal emitted from a vehicle speed sensing apparatus according to a preferred embodiment of the present invention.
3 is a view for explaining an irregular laser firing time in accordance with a preferred embodiment of the present invention.
4 is a flowchart illustrating a vehicle speed sensing method using a laser according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily understand and reproduce the present invention.

In the following description of the present invention, when it is determined that detailed descriptions of related known functions or configurations may unnecessarily obscure the gist of the embodiments of the present invention, the detailed description thereof will be omitted.

Prior to describing the present invention, terms used throughout the specification may be sufficiently modified according to the intention, customs, etc. of the user or operator, and the definition of the terms should be made based on the contents throughout the specification of the present invention. will be.

The present invention relates to a vehicle speed sensing device and method for irregularly firing a laser signal for vehicle speed detection, so that the laser disturbance device does not detect the vehicle speed sensing device.

In the present invention, the regular firing point means that the laser signal is continuously fired at a predetermined period, and the firing point is irregular means that the laser signal is continuously fired without a predetermined period.

1 is a diagram illustrating an internal configuration of a vehicle speed sensing apparatus according to a preferred embodiment of the present invention.

The transmitter 110 aims and fires a laser signal at a vehicle for speed measurement. According to an exemplary embodiment of the present disclosure, the transmitter 110 continuously fires a laser signal several times at an irregular firing time under the control of the controller 120.

The receiver 130 receives the laser signal reflected back to the vehicle and outputs the laser signal to the controller 120.

The timer 140 is a device for measuring the time taken for the laser signal emitted back to the vehicle reflected back, is driven when the laser signal is fired in connection with the transmitter 110, the laser signal is connected to the receiver 130 To check the return time. Timer 140 is tens or hundreds of picoseconds: may output a (pico second 10 ^-12), control unit 120 possible time measurement unit, by counting the number of the reference clock to the feedback time from the firing time of the laser signal . The timer 140 expires after a predetermined time elapses from the laser firing time point under the control of the controller 120 and is reset.

The random number generator 150 is used to adjust the laser firing point to be irregular, and generates a random number in a predetermined range and outputs it to the controller 120. Here, the random number refers to a number that is selected to have the same probability of occurrence in any set of known numbers. Such random numbers are used in many fields, such as computer programming, simulation modeling, and cryptographic key generation for various systems, among which are typically used for software routines with a lot of rammer generators using the multiplicative linear concatenation. Used.

The controller 150 serves to detect the vehicle speed according to the present invention by controlling the aforementioned components, and controls the laser signal firing timing of the transmitter 110 to be irregular according to a preferred embodiment of the present invention.

As described above, most laser disturbance devices generate a disturbance signal upon receiving a regular laser signal. Accordingly, in the present invention, the laser signal firing point is irregular as shown in FIG. 2.

However, even if the launching point is irregular, the present invention adjusts so that the launching point is irregular by the random number generator 150 to measure the speed, which is the original function of the vehicle speed sensing device.

3 is a view for explaining a time point for detecting a vehicle speed.

Referring to FIG. 3, the vehicle speed sensing method includes a calibration mode and a measurement mode.

In Calibration mode, the necessary parameters for vehicle speed detection are set and the hardware is in the best condition. In addition, in measurement mode, the time indicated by MR2 + MR0 means the time when the laser signal is actually fired, and the time indicated by MR3 + MR0 indicates the time when the feedback signal of the fired laser signal is waiting to be received. it means. That is, since the timer 140 is driven at the time MR2 + MR0 and expires at the time MR3 + MR0, the signal received after the time MR3 + MR0 becomes invalid.

As described above, the controller 120 may use Equation 1 below to irregularize the laser signal firing timing MR2 + MR0.

Here, T is a constant representing a specific time and may be, for example, 32 microseconds. R means a random number output by the random number generator 150 and may be 0 to 15.

That is, the laser signal firing time points according to the present invention may appear irregular, but all have a consistency that is an integer multiple of a specific time T.

The controller 120 measures the vehicle speed by using the time measured by the timer 140 after the transmitter 110 emits the laser signal. Typically, the light travels about 0.3 mm in one pico second. Therefore, the controller 120 may measure the distance by using a time difference between the firing time and the returning time measured by the timer 140. That is, the value obtained by multiplying the measured time difference in picosecond units by 0.3 mm is the round trip distance value of the laser signal, and the distance to the vehicle is the round trip distance value divided by two.

The control unit 120 calculates the distance data from the time difference from the time of hitting the vehicle back to the vehicle by continuously firing the laser several times as described above, and calculates the speed using the calculated rate of change of the distance data.

Meanwhile, the controller 120 may perform a function of detecting the presence of the laser disturbance device. To this end, the controller 120 stops the operation of the random number generator 150, controls the transmitter 110 to fire the laser several times at regular laser firing times, and thus the signal received through the receiver 130 becomes irregular. Find out whether or not there is a change. As a result of the determination, when the received signal is changed, the controller 120 determines that the laser disturbance device exists. If it is determined that the laser disturbance device exists, the controller 120 then operates the random number generator 150 again to measure the vehicle speed.

In the above description, the random number generator 150 is connected to the controller 120, and the controller 120 calculates a launch time and measures a vehicle speed. However, the transmitter 110 is connected to the random number generator 150. You can also calculate the launch time directly.

4 is a flowchart illustrating a vehicle speed sensing method according to an exemplary embodiment of the present invention.

Referring to FIG. 4, the apparatus for detecting a vehicle speed performs a calibration operation for setting a parameter although not shown in the figure in performing a vehicle speed measurement operation. In operation 410, the vehicle speed detecting apparatus calculates an irregular laser signal firing time point using random numbers such that the laser disturbance device does not detect the speed measuring laser in calculating the firing time point in step 410. .

In operation 420, the vehicle speed detecting apparatus emits a laser signal to the vehicle to detect the speed at the calculated launch time. In operation 430, it is determined whether a reflected signal is received. If it is determined in step 430 that the reflected signal is received, the vehicle speed detecting apparatus calculates the distance to the vehicle through the time difference between the launch time and the return time. However, if it is determined in step 440 that the reflection signal is not received and the timer expires in step 440, the process proceeds to step 410 again.

After the 450 distance measurement is finished, it is determined whether to fire the laser signal in step 460, to determine whether the laser signal has been fired a predetermined number of times in order to secure sufficient distance data for speed measurement. By doing so, steps 410 through 450 are repeated a predetermined number of times.

The vehicle speed detecting apparatus repeats steps 410 to 460 several times to collect sufficient distance data, and measures the speed of the vehicle in step 470 through the collected distance data.

After the speed measurement of the vehicle is completed, the vehicle speed detecting apparatus continuously fires a laser signal having a regular launch time several times in order to detect the laser disturbance apparatus in step 480. If the random number generation unit is being driven by the vehicle speed measurement operation previously, the random number generation is temporarily stopped.

In operation 490, the vehicle speed detecting apparatus determines whether an error occurs in the feedback signal. That is, it is determined whether the feedback signal is irregular different from the transmission signal or whether there is an error in the feedback signal depending on whether the distance is changed. If it is determined that an abnormality has occurred in the signal received in step 490, the vehicle speed detecting apparatus determines that there is a laser disturbance device that is operated to disturb the received signal in step 500.

As described above, when it is determined that the laser disturbance apparatus exists, although not shown in the drawing, the vehicle speed sensing apparatus may measure the vehicle speed by driving a random number generator in the subsequent speed measurement.

On the other hand, if it is determined in step 490 that the reception signal is intact, the vehicle speed detecting apparatus determines that there is no laser disturbance apparatus in step 510. Thus, the laser disturbance device may confirm that the laser signal previously used for vehicle speed measurement has not been disturbed.

Therefore, when it is determined that the laser disturbance device does not exist, the random number of steps 410 to 470 described above is not shown in the figure, but the above-described steps for preventing the existence of the undetected laser disturbance device in performing the speed measurement. A speed measurement operation using or a speed measurement operation not using a random number may be selectively performed.

100: vehicle speed detection device 110: transmitter
120: control unit 130: receiving unit
140: timer 150: random number generator

Claims (10)

Timer for measuring the time difference between the transmitter for aiming and firing the laser signal to the vehicle for distance measurement, the receiver for receiving the laser signal reflected back from the vehicle, and the time of firing the laser signal and the return point reflected back In the vehicle speed sensing device using a laser comprising a control unit for extracting the moving distance data of the moving object to determine the final speed of the vehicle by analyzing the time difference,
Including a random number generator for generating and outputting a random number,
The control unit calculates one or more irregular laser firing time points using random numbers outputted from the random number generating unit, and controls the transmitter so that the laser is fired at the calculated one or more firing time points. Speed sensing device.
The apparatus of claim 1, wherein the control unit
And a time between the launch time and the launch time is an integer multiple of a predetermined time.
The apparatus of claim 1, wherein the control unit
And firing a laser signal a predetermined number of times at a regular firing time, and then determining whether a laser disturbance device exists according to a return timing or a moving distance of the returned signal.
The method of claim 3, wherein the control unit
And, if it is determined that a laser disturbance device exists, controlling the random number generator to be driven.
The method of claim 1, wherein the timer is
Vehicle speed sensing apparatus using a laser, characterized in that expires if the feedback signal is not received for a predetermined time after the launch time.
Calculating a launch time of an irregular laser signal using a random number,
Launching a laser signal to a vehicle for velocity measurement at the calculated launch time;
Receiving the laser signal reflected back to the vehicle,
Measuring a time difference between the firing point of the laser signal and the returning point reflected back;
And determining final speed of the moving object by extracting moving distance data of the moving object by analyzing the time difference.
7. The method of claim 6, wherein calculating the launch time
Vehicle speed sensing method using a laser, characterized in that the time between the launch time from the reference time is an integer multiple of a predetermined time.
The method of claim 6,
And firing a laser signal a predetermined number of times at a regular firing time, and then determining whether a laser disturbing device exists according to a return timing or a moving distance of the returned signal. Detection method.
The method of claim 8, wherein the calculating of the launch time
If it is determined that there is a laser disturbance device, the vehicle speed detection method using a laser, characterized in that for calculating the launch time using the random number.
The method of claim 6, wherein receiving the laser signal
Vehicle speed sensing method using a laser, characterized in that the feedback signal waits for a predetermined time after the launch time.

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