KR20050069060A - System for preventing rear-ending for vehicle - Google Patents

Abstract

A vehicle collision prevention system is disclosed. The disclosed vehicle collision prevention system is installed in front of a rear vehicle and emits light having different wavelengths according to the degree of view from the light emitting surface to the front vehicle traveling in front of the rear vehicle, thereby adjusting the distance and angle with the front vehicle. A light source element consisting of a photon laser for sensing; And a light receiving element installed at a rear of the front vehicle and formed of a spatial filter that detects a signal received at an angle that varies geometrically and optically according to the inter-vehicle distance and reversely detects the inter-vehicle distance.

According to the present invention, it is possible to realize the optical RCAS by finding the distance and the acceleration between vehicles without complicated signal processing.

Description

Vehicle collision prevention system {SYSTEM FOR PREVENTING REAR-ENDING FOR VEHICLE}

The present invention relates to a vehicle collision prevention system, and more particularly, to a vehicle collision prevention system using angle sensing light technology.

Among the Intelligent Transportation System (ITS), the Advanced Vehicle and Highway System (AVHS) and the Rear-end Collision Avoidance System (RCAS) technology are used to recognize vehicle and object access in front, side and side of the driving vehicle for controlling the vehicle. High performance sensors and automatic control devices are required, and to this end, technologies such as millimeter wave radar and ultrasound are pursued.

The millimeter wave vehicle radar uses a transmission signal emitted by a radar attached to the front of a vehicle and a reception signal reflected from a vehicle traveling in front of the vehicle, and a time difference between the transmission signal and the reception signal and a frequency due to the doppler effect. The difference is measured to calculate the distance and relative speed with the vehicle ahead. Triangular waveforms are mainly used to control voltage controlled oscillators (VCOs) that generate signals from radar.

In addition, the ultrasonic sensor is used to determine the distance measurement or the presence or absence of an object in front of the light due to the small influence on the reflection of light due to the nature of sound and its simplicity of processing. The biggest advantage is that you do not have to design a complex filter because it is not affected by natural light, but the accuracy of the distance measurement is inferior due to the wavelength incomparable with electromagnetic waves.

In addition, the millimeter wave vehicle collision device on the freeway is already commercialized overseas, but it is limited to high-end brands such as Cadillac and Jaguar-class cars.

And in a crowded place in a crowded city center, it is necessary to measure not only long distances of highways, but also short distance and side distances and devices considering curved road conditions.

However, a vehicle collision device using a millimeter wave has an advantage that it is less affected by changes in weather and surrounding environment.

In addition, since the actual road environment has obstacles such as complex structures and road shapes, the vehicle collision device using the millimeter wave implements a beam scan antenna. As the scan method, a mechanical scan method and a switched beam method are used.

In addition, the switch scan method may be implemented in a simple structure, but the distance resolution is low, and the mechanical scan method generates a narrow pattern to maintain high resolution, but mechanical reliability must be preceded and the size of the antenna is increased. Has its drawbacks.

In addition, the relationship of the output frequency to the control voltage of a typical VCO does not have a linear relationship, and this causes distortion of the measurement result, thereby reducing the accuracy of the measurement. As a correction method for this problem, a correction method for modifying the waveform of the control voltage of the VCO and a signal processing method applying a reference signal to the measurement result are used. As a result, the complexity of the algorithm, the time delay and the cost of the distance measurement are used. There is this expensive problem.

The present invention has been made to solve the above problems, and the characteristics (OASIS: Optical Angle Sensing Integrated Spectrum) and Spatial Optical Filter (SOF) for detecting the angle according to the wavelength change of the PQR laser ) And a photodiode (PD) in combination with a distance measurement module to detect the distance and acceleration between vehicles without complex signal processing process to provide an optical RCAS to provide a vehicle collision prevention system.

The vehicle collision prevention system of the present invention for achieving the above object is installed in the front of the rear vehicle, and emits light of different wavelengths according to the viewing angle from the light emitting surface to the front vehicle running in front of the rear vehicle. A light source element comprising a photon frame laser for detecting a distance and an angle with the front vehicle; And a light receiving element installed at a rear of the front vehicle and formed of a spatial filter that detects a signal received at an angle that varies geometrically and optically according to the inter-vehicle distance and reversely detects the inter-vehicle distance.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 1 is a schematic diagram showing the configuration of a vehicle collision prevention system according to the present invention.

Referring to the drawings, the first embodiment of the vehicle collision prevention system according to the present invention is provided in front of the rear vehicle 10 and is driven from the light emitting surface of the front vehicle 20 traveling in front of the rear vehicle 10. A light source element 30 formed of a photonic quantum ring (hereinafter referred to as a PQR) laser that emits light of different wavelengths according to a degree of vision, and detects a distance and an angle with the front vehicle 20; Spatial Optical Filter (hereinafter referred to as SOF) which is installed at the rear of the front vehicle 20 and detects a signal received at an angle that varies geometrically optically according to the inter-vehicle distance and reversely detects the inter-vehicle distance. It is configured to include a light receiving element 40.

The PQR laser is used as a three-dimensional wide-area light source when the distance to the front vehicle 20 is close to 10-20 m.

In addition, the light receiving device 40 is a second embodiment of the vehicle collision prevention system according to the present invention, and includes a SOF for calculating a distance by separating wavelengths emitted differently according to angles in the PQR laser.

In addition, as a third embodiment of the vehicle collision prevention system according to the present invention, the light source element 30 can focus the laser beam to a narrow area of a desired point using a predetermined lens to detect a narrow-range long distance of 20 to 30m distance. Edge Emitting (EE) lasers used may be used.

As described above, the light source device 30 and the light receiving device 40 are related to a two-way RCAS installed at the front and the rear of another vehicle 10 and 20, respectively.

Although the fourth embodiment of the other vehicle collision prevention system according to the present invention is not shown in the drawing, it is provided in front of the vehicle, and is a light source for irradiating light to the tail light of the front vehicle which is traveling in front of the vehicle. And an integrated one-way collision prevention device in which an element and a light receiving element for receiving a signal having an angle calculated in advance according to a distance of a signal reflected from the rear light of the front vehicle are integrally formed.

In the collision preventing apparatus, the light source element is a PQR laser, and the light receiving element is formed of an optical filter.

Although not shown in the drawings, the vehicle collision prevention system according to the present invention may employ a photodiode (hereinafter referred to as a photo diode; PD) and an optical spectrum analyzer in addition to the above-described configuration for measuring distance and angle. . Since this is generally known technology, a detailed description thereof will be omitted.

Referring to the operation of the vehicle collision prevention system according to the present invention having the configuration as described above are as follows.

The vehicle collision prevention system according to the present invention makes a distance measurement module by combining an angle (OASIS: Optical Angle Sensing Integrated Spectrum) and SOF and PD to detect the angle according to the wavelength change of the PQR laser.

This distance measurement module realizes optical RCAS by finding the distance and acceleration between vehicles without complicated signal processing.

Three-dimensional wide area measurement can be performed by the PQR laser and the WOF or SOF method, and a long range narrow measurement is possible by the combination of the EE laser and the SOF or WOF.

This will be described in more detail.

The vehicle collision prevention system according to the present invention is a distance and angle sensor for preventing collision of a vehicle by using a phenomenon in which the PQR laser emits light of different wavelengths in three dimensions according to the degree of vision from the light emitting surface.

On the other hand, the structure and characteristics of the PQR laser is disclosed in Korean Patent No. 0288612 (Photon laser laser diode and its array and manufacturing method) and US Patent No. 6,519,271 (Photonic Quantum Ring Laser Diode), the angle detection using the same The characteristics related to the sensor are disclosed in Korean Patent No. 0260271 (Angle and altitude measuring device using a photon laser).

The vehicle collision prevention system according to the present invention is an extension of the angle sensing optical RCAS technology which can grasp the approach of an object and a vehicle based on the above two patents.

As shown in FIG. 1, the vehicle collision prevention system according to the present invention includes a light source element 30 and a light receiving element 40. Hereinafter, light according to the arrangement of the above-described elements 30 and 40 is described. The RCAS method is described separately.

First, as the light source element (LDA: Laser Diode Array) 30, a single PQR laser exhibits a microA-class microcurrent operation, and OASIS characteristics according to three-dimensional multi-wavelength characteristics in which the spectrum of the laser appears three-dimensionally according to the output angle. Has The multi-wavelength characteristic according to the output angle is a very original technology, and it is possible to develop a new concept of laser azimuth (or vision) sensor that can replace the existing infrared sensor or camera, and extend the sensing distance in the case of highly integrated module. This is possible.

Figure 2 shows the wavelength characteristics for each angle of the 4K PQR laser.

In addition to the broadening of the line width due to the increase in the degree of integration of the light source device, the spectral characteristics similar to those of a single PQR laser can be confirmed. This shows that the OASIS characteristics of the PQR laser can be applied at a long distance.

Figure 3 shows the change in the intensity of the light according to the distance appearing during the oscillation of each device.

It can be seen that the light intensity according to the distance and angle increases as the array density increases. In the case of 8K (4K × 2) PQR, it can be seen that the application of the angular characteristic up to 10 m is possible.

As shown in FIGS. 2 and 3, the width of the sensing region is widely distributed in three dimensions due to the multi-wavelength characteristic according to the angle, and thus, there is no need to scan a beam directly over the entire sensing region. However, when used over a long distance of more than 20-30m, the high power consumption of the highly integrated PQR chip is the best, it is most suitable for the detection of wide-angle wide angle.

And as another light source element, the EE laser does not have a three-dimensional angle-wavelength OASIS phenomenon like the PQR laser. However, since the lens can focus the laser beam into a narrow area at a desired point, it can be used for narrow-range remote sensing at a distance of 20 to 30m.

This is because applying the SSC (Spot Size Converter) technology to the fabrication of commonly used EE lasers and attaching an appropriate lens can adjust the transverse mode pattern of the laser beam to the required shape.

4 and 5 show the relationship between the lateral mode area and the power that increases with distance after attaching a lens having an appropriate focal length to the EE laser (EELD).

The 30m range power of an EE laser with near-power ~ 3.3mW represents 0.6mW. Here, the power after the mode magnification through the lens represents 154 nW. Since 154 nW is higher than the basic noise to several nW (weekly road noise reaching PD through SOF), the signal can be detected. Furthermore, increasing the laser power will allow for remote sensing at the same time as sensing all the appropriate area.

Therefore, it is possible to use it as a long-distance light source of RCAS technology by increasing the output by EE laser and enlarging the signal area to the desired size using a light converging process technology such as SSC and the lens, and adding SOF technology as the light receiving element 40. Do.

In this way, the light source element uses a PQR laser as a three-dimensional wide-area light source for the near distance (within 10-20 m) wide area and the near side rectangular device. And for the long range (more than 20 ~ 30m) narrow-range device, EE laser uses the light source component which combines SSC-like light focusing process technology and optical lens. In addition, when the emission wavelength of the laser of the light source element is selected as 1.4 to 1.5im, a long wavelength laser diode (LD) semiconductor structure such as InGaAsP is used.

In order to implement RCAS having the simplest structure, minimum cost, and minimizing signal processing by using the OASIS characteristic of the PQR laser, WOF as the light receiving device 40 may separate wavelengths emitted differently according to angles in the PQR laser. WOF is required.

As shown in FIG. 6, the angle is determined according to the distance between the vehicles, and when the wavelength corresponding to the angle is separated by the WOF, the distance can be directly calculated. The specification of WOF required for this requires transmission bandwidth sharpness of Δλ = 0.07nm in 20m class and Δλ = 0.28nm in 10m class. Conventional filter fabrication techniques require Δλ = 2 to 3 nm, far below the required specifications, and therefore require new fabrication techniques.

On the other hand, the existing filter in the form of a multilayer thin film can be used to remove solar noise generated during the day near the oscillation wavelength of the PQR laser.

FIG. 7 shows a spectral distribution in which solar noise is removed by using a band pass WOF of Δλ = 25 nm and a high pass (600 nm to) WOF. The PQR laser oscillation wavelength is ~ 780nm, and the combination of bandpass / highpass filter can be confirmed that noise other than 780nm is removed.

As the light receiving element 40, the SOF uses the principle of detecting the wavelength by the WOF detecting the wavelength (because of the wavelength characteristic of each PQR laser) and detecting the distance between the angles. Geometrically optically detects incoming signals at angles that vary with the distance between vehicles and vice versa.

Due to this principle, a new technology SOF is solved which solves the problem of transmission line width sharpness of WOF, thereby increasing the practicality of optical RCAS technology. An example of the basic principle of SOF and angle / distance / error information is shown in the tables of FIGS. 8 and 9.

On the other hand, Fig. 3 is a data measured by a precision instrument inside a laser laboratory, while the data in the table of Fig. 9 is measured using cheap PD devices in a real-world situation of a pilot test level, and thus the short-range data Is showing.

As mentioned above, the RCAS module of the PQR laser and WOF combination is most suitable, but considering the power consumption and wavelength characteristics, the short-range and lateral rectangular treatment is a combination of the PQR laser, WOF and SOF, and the distance (20 ~ 30m or more) EE laser with WOF and SOF combination is used.

In the system configured as described above, the rise time of the laser light source of the light source element, the rise time of the high speed PD with a 50 Ω load resistor, and the response time of informing the vehicle alarm if the signal moving distance are ignored Can expect ~ nsec. The directionality angle can be arbitrarily adjusted by using a laser and a lens of the light source element.

Hereinafter, the optical RCAS implementation will be described.

First, the two-way RCAS (light source-receiving separation type) will be described. FIG. 6 is a schematic diagram of the optical RCAS, and the angle-by-angle signal of the highly integrated PQR laser oscillated from the rear of the front vehicle is angled using the SOF mounted on the rear vehicle. It shows the value of the signal detected by the conversion to the voltage signal.

The PQR oscillated in the front vehicle emits a three-dimensional stereoscopic spectrum to the rear car and SOF detects the PQR laser signal when the inter-vehicle distance creates an angle corresponding to a specific distance already calculated.

Sunlight and other noise are pre-filtered by the WOF attached in front of the SOF. The signal passing through the SOF forms a photocurrent through the PD and outputs a voltage signal. The base level voltage is 0.26V when the initial distance is further 2.5m (35 ° angle), but when the distance is 2.5m, the pulse signal detection voltage of the PQR laser (pulse) signal detection voltage) increases to 0.67V.

That is, it is reasonable to adopt a voltage threshold that distinguishes a signal from noise as ~ 0.6V in a relation such as 0.26V <VTH <0.67V. The distance according to the angle can be calculated by selecting VTH = 0.4V at an angle of 60 ° corresponding to 1m and 0.3V at an angle of 74 ° corresponding to 50cm.

The output voltage signal generates acceleration information between the object and the sensor through a signal processing process, and the approach vehicle is recognized (constant speed driving, decelerating driving, following driving, acceleration driving) through the scale of this information. In other words, the angle information itself has distance information without conversion. The relationship regarding distance, angle, and distance precision is shown in the table of FIG.

The distance and angle detection module detects a signal of an angle corresponding to a specific distance, so that distance and speed information can be sufficiently known, and an economical sensor can be realized in terms of price.

As shown in Fig. 6, the point P (near the headlight of the rear vehicle) indicates the attachment position of the SOF and the WOF, as shown in Fig. 6, from the angle information (distance information) obtained through this module. The angle that the vehicle makes with the module at the time t1 approaching the point A becomes θ1, and the distance between the cars from the angle information. Can be found exactly.

Similarly, the distance between the times t2 and t6 Wow Can be obtained respectively. Once the absolute distance between vehicles is found, the velocitys υ12 and ν23 and the acceleration a can be obtained.

, ,

The distance, speed, and acceleration information obtained above are important values for avoiding and preventing collisions of the vehicle. When the vehicle approaches or falls below a certain distance by judging acceleration / deceleration in signal processing, a warning device or a steering device and By controlling the braking system automatically, the collision can be avoided.

In addition to the front bumper of the vehicle, the distance and angle detection module can be installed on both sides of the vehicle to be applied to the near side blind spot treatment of the vehicle.

It is also possible to trigger an alert without delay in such an optical RCAS alarm system. That is, θ1 is detected, θ2 is detected after t seconds, and a warning can be activated.

That is, the t second period is used as a warning spare time, and a warning is triggered without delay upon detection of θ2. On the other hand, the shorter the t seconds, the stronger the warning.

Next, one-way RCAS (light source-receiving integrated type) will be described.

If the two-way RCAS as described above to separately install the light source element and the light receiving element to each of the front and rear, the one-way RCAS is a method of mounting both the light source and the light receiving element as a module to be mounted in a vehicle. The signal generated by the PQR laser or the EE laser enters the rear light (Corner Cube Retroreflector (hereinafter referred to as CCR)) of the vehicle driving in front. After entering, the reflected signal enters the light-receiving unit consisting of WOF and SOF with a pre-calculated angle according to the distance.

The light entering the CCR is due to the inherent property of the CCR that reflects back into the light source of the light after reflection. In the case of one-way RCAS, this principle is possible because the light source and the light receiver are modularized together. The signal returned after reflecting to the CCR of the front vehicle extracts the distance / acceleration information through the PD through the same principle as the two-way RCAS.

As described above, the vehicle collision prevention system according to the present invention has the following effects.

The optical RCAS system can be implemented by finding the distance and acceleration between vehicles without complicated signal processing.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent embodiments are possible. Therefore, the true scope of protection of the present invention should be defined only by the appended claims.

1 is a view schematically showing the configuration of a vehicle collision prevention system according to the present invention.

Figure 2 is a graph showing the wavelength characteristics for each angle of the 4K PQR laser.

Figure 3 is a graph showing the power for each angle of the 1k / 8K PQR laser.

4 shows EE laser lateral mode dispersion using a lens.

5 is a table showing a change in the transverse mode area and power with distance.

6 shows an angle detection voltage of a PQR laser signal through the SOF.

7 is a graph illustrating solar noise cancellation using WOF.

8 shows a distance and angle detection module (WOF + SOF).

9 is a table showing the relationship between the distance and angle of SOF

<Description of Symbols for Main Parts of Drawings>

10. Vehicle

30. Vehicles in front

30. Light source element

40. Light receiving element

Claims (6)

The photon laser is installed in front of the rear vehicle, and emits light of different wavelengths according to the visual angle from the light emitting surface to the front vehicle traveling in front of the rear vehicle. A light source element; And a light receiving element installed at a rear of the front vehicle and formed of a spatial filter that detects a signal received at an angle that varies geometrically and optically according to the inter-vehicle distance, and reversely detects the inter-vehicle distance. . The method of claim 1, And the photon frame laser is used as a three-dimensional wide-area light source when the distance to the front vehicle is within 10 to 20 m. The method of claim 1, The light receiving device, the vehicle collision prevention system, characterized in that it comprises an optical filter for calculating the distance by separating the wavelength emitted differently according to the angle in the photon frame laser. The method of claim 1, The light source element is a collision prevention system, characterized in that it comprises a single-sided light emitting laser which can focus the laser beam to a narrow area of a desired point using a predetermined lens and is used for narrow-range long distance detection of 20 to 30m distance. It is installed in front of the vehicle, the light source element for irradiating and incident light to the tail light of the front vehicle running in front of the vehicle, and the signal reflected from the tail light receives a signal having a pre-calculated angle according to the distance Vehicle collision prevention system comprising an integrated one-way collision prevention device made of a light receiving element. The method of claim 5, The light source element is a photon frame laser, the light receiving element is a vehicle collision prevention system, characterized in that consisting of an optical filter.