KR100255173B1 - Scanning laser radar - Google Patents

Abstract

PURPOSE: A scanning laser radar is provided to reduce the number of components and save manufacturing cost by enabling receipt and transmission of a light wave through one path. CONSTITUTION: A transmitter(21) transmits a laser beam of a certain magnitude of wavelength. A receiver(28) detects a reflected wave of the laser beam from the transmitter(21). A reflector(23) reflects the laser beam from the transmitter(21) to an obstacle detection area, and the laser beam reflected from an obstacle to the receiver(28). A reflector driving unit(24) drives the reflector(23). A position detector(29) detects the reference position of the reflector(23). A transmitter lens(22) and a receiver lens(27) are respectively arranged between the transmitter(21) and the reflector(23) and between the receiver(28) and the reflector(23) to focus the laser beam. A protector glass(25) shields inflow of dust and dirt. An actinometer(31) varies the obstacle detection area.

Description

Scanning Laser Radar

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning laser radar, and more particularly, to a scanning laser radar used in an anti-collision warning device of a vehicle.

In general, an anti-collision warning device of a vehicle uses pulse reflection of electromagnetic waves (light waves) and elastic waves (ultrasound waves), and calculates a distance from an obstacle by measuring a time interval between a transmission pulse and a reflected wave, and calculates a distance and a braking distance, In addition, when it is determined that there is a possibility of collision by comprehensively considering the relative speed between the obstacle and the own vehicle, the alarm operation is performed.

That is, as shown in Figure 1, the conventional vehicle anti-collision alarm device obtains information on the obstacle by using the scanning laser radar, briefly described as follows.

First, the configuration is largely a transmitter for transmitting a laser beam in the direction to detect the presence of obstacles, a receiver for receiving the reflected wave of the transmitted laser beam, and measurement of the time interval between the transmitted laser beam and the reflected wave and collision prevention It consists of a control unit that performs the overall control operation of the alarm device.

The above-described light transmitting unit includes a transmitter 1 for transmitting a laser beam having a wavelength of a certain size, a light transmitting lens 2 for focusing the laser beam transmitted by the light transmitter 1, and a laser beam focused from the light transmitting lens 2 The light reflecting mirror 3 and the driver 4 for adjusting the angle of the light reflecting mirror 3, and the light reflecting mirror 3 and the light reflecting mirror 3 to reflect the light at a predetermined angle. The protection glass 5 for protection, and the dirt detector 6 for detecting the absorption of dirt by detecting the laser beam reflected by the dirt absorption of the protection glass (5).

The light receiving unit reflects the optical filter 7 for passing only the reflected wave of the laser beam transmitted during the light received from the outside and the laser beam passing through the optical filter 7 at a predetermined angle to transmit the light toward the light receiving lens 10. The driver 4 for adjusting the angle of the reflector 8 and the light receiving reflector 8, the light receiving lens 9 for focusing the reflected wave transmitted from the light receiving reflector 8, and the laser beam transmitted from the light receiving lens 9. And a protective glass 11 for protecting the light receiver 10, the optical filter 7, and the light reflecting mirror 8.

The control unit 11 calculates the distance to the obstacle through control of the light transmitting operation of the transmitter 1, the light reflector driving unit 4, and the light receiving operation of the receiver 10, and performs an alarm operation according to the calculation result. do. In addition, the dirt detector 6 detects the adsorption state of the dirt 12 on the protective glass.

Hereinafter, the operation of the scanning laser radar of the conventional vehicle anti-collision warning apparatus will be described with reference to the above-described configuration.

When the collision avoidance warning device of the vehicle is operated, the laser beam is transmitted from the transmitter 1, is focused at the transmitter lens 2, and is reflected at a predetermined angle by the transmitter reflector 3 to detect the presence of an obstacle. The light is transmitted to the front of the vehicle. The laser beam transmitted forward is reflected when it meets an obstacle, and the reflected laser beam is captured by the light receiver 10 to check whether there is an obstacle in front of the laser beam. That is, the reflected laser beam passes through the protective glass 11 and is bent at a predetermined angle by the light receiving reflector 8 to be transmitted toward the light receiving lens 9. Therefore, the laser beam focused by the light receiving lens 9 is received by the light receiver 10, thereby detecting the presence or absence of an obstacle. In addition, by converting and amplifying the received laser beam into an electrical signal, the amplified electric signal may be configured to increase in proportion to the distance to each obstacle, thereby calculating the distance to each obstacle.

However, the scanning laser radar used in the conventional vehicle anti-collision warning device has the following problems.

First, the light reflecting mirror and the light reflecting mirror are provided separately, and the process of adjusting each reflecting mirror to achieve 90 ° to each other during the assembly process should be separately performed. In addition, since the light transmitting part protection glass and the light receiving part protection glass are separately provided, the dirt detection of the light transmitting part protection glass is well detected by the dirt detection, while the dirt detection of the light receiving part protection glass is not made, which causes an error when detecting an obstacle. It became. In addition, a separate optical filter was provided on the light-receiving part side, and the assembly process and the number of parts were added, causing a cost increase. In addition, since the driving unit for adjusting the angle of the reflector is driven only at a predetermined angle, there is a limitation in providing a variety of information to the driver because the obstacle detection area is limited.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to provide a scanning laser radar that can reduce the number of parts and manufacturing cost by allowing light waves to be received and transmitted through one path.

Another object of the present invention is to provide a scanning laser radar which improves the reliability of the device through the initial position detection of the reflector and the contamination detection of the protective glass.

It is still another object of the present invention to provide a scanning laser radar capable of varying an obstacle detection area according to a road illumination environment.

1 is a block diagram of a conventional scanning laser radar,

2 is a block diagram of a scanning laser radar according to the present invention;

3 is a block diagram of an optical filter of a scanning laser radar according to the present invention;

4 is a reflection angle of the reflector of the scanning laser radar according to the present invention

* Description of the symbols for the main parts of the drawings *

21: transmitter 22: light transmitting lens 23: reflector

24: reflector drive unit 25: protective glass 27: light receiving lens

28: receiver 29: position sensor 30: dirt

31: light intensity sensor 40: control unit

The configuration of the present invention for achieving the technical problem, a transmitter for generating and transmitting light waves of a specific frequency band, a reflector for reflecting the light waves transmitted from the transmitter in the direction to detect the obstacle, the specific reflection mirror A driver for rotating at an angle, a light receiver reflecting and receiving the light waves reflected and transmitted by the reflector from the reflector, and receiving and receiving the light waves reflected from the reflector, light waves reflected and transmitted from the reflector, and received and reflected from the reflector The protective glass is provided on the path of the light waves, and the protection glass for blocking the incoming dirt from the outside, the light amount sensor for measuring the external illuminance, and the light waves transmitted from the transmitter are reflected by the obstacle and returned to the receiver. The distance to the obstacle is calculated by calculating the received time. And a controller for performing an alarm operation as necessary and varying the obstacle detection area by rotating the reflection angle of the reflector by controlling the driving unit according to an external illuminance read from the light quantity sensor. .

Hereinafter, one preferred embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram of a scanning laser radar according to the present invention, FIG. 3 is a block diagram of an optical filter of a scanning laser radar according to the present invention, and FIG. 4 is a view illustrating a rotation angle of a reflector driving unit of a scanning laser radar according to the present invention. will be.

First, as shown in FIG. 2, the scanning laser radar according to the present invention includes a transmitter for transmitting a laser beam in a direction to detect the presence of an obstacle, a receiver for receiving a reflected wave of the transmitted laser beam, and a transmitted laser. It is largely composed of a control unit for measuring the time interval between the beam and the reflected wave and performing the overall control operation of the collision avoidance warning device.

That is, the transmitter 21 for transmitting the laser beam having a wavelength of a certain size, the receiver 28 for detecting the reflected wave of the laser beam transmitted from the transmitter 21, and integrally formed and the transmitter 21 Reflecting the laser beam transmitted from the laser beam at a predetermined angle to transmit the light to the obstacle detection area, reflecting the laser beam reflected by the obstacle at a predetermined angle to guide the receiver 28 and the reflector driver 24 And a position sensor 29 for checking the reference position of the reflector 23, and between the transmitter 21 and the reflector 23, and between the receiver 28 and the reflector 23, respectively. The light transmitting lens 22 and the light receiving lens 27 for focusing the beam, the protective glass 25 for blocking the inflow of dust and other dirt from the outside, and also varying the detection area of the obstacle according to the illumination environment of the road. Light quantity sensor 31 and the like.

Of the above-described components, the reflector 23 includes the conventional transmitting and receiving reflecting mirrors 3 and 8 integrally. For this purpose, the transmitter 21 and the receiver 28 are installed in the same direction. It is arranged left and right or up and down so as not to be affected. In addition, the reflector 23 is paired with the protective glass 25 to be described later to serve as a band pass filter.

And the position sensor 29 is for detecting the initial position of the reflector 23, which is to perform the rotation operation set by the control unit 40 when the vehicle's anti-collision alarm system is initially operated. That is, the laser beam transmitted from the transmitter 21 is reflected at a predetermined angle by the reflector 23 which is rotated. At this time, the position of the reflector 23 is received by the position detector 29 to adjust the initial position of the reflector 23. Will be set. Therefore, the controller 40 may initialize the reflector 23 and then control the reflector 23 according to a control procedure.

In addition, the protective glass 25 serves as a path for the laser beam and the reflective beam transmitted from the transmitter 21 and a cover for blocking the inflow of dust such as dust from the inside into the collision avoidance alarm device, and the aforementioned reflector ( Paired with 23) performs the filter role. That is, as shown in Figure 3, the light wave incident on the light receiver 28 is very diverse in wavelength, and when receiving the light wave having the wavelength of all these areas in the light receiver 28, in the obstacle detection It may cause malfunction. Therefore, when the transmitted laser beam is reflected back to the obstacle and the wavelength is λa, the protective glass 25 transmits to the wavelength λb larger than λa and blocks more than that. The reflector 23 reflects up to a wavelength lambda c which is smaller than lambda a by a predetermined value, and absorbs less than that. Therefore, the light received by the light receiver 28 is limited to a wavelength having a predetermined value including lambda a so that the reflected wave can be detected well. In addition, the protective glass 25 is integrated with the conventional protective glass (5, 11) provided on the light transmitting portion side and the light receiving portion side, which is, as described above, the light transmitting and receiving light reflector 23 is integrally manufactured, The transmission path of the laser beam and the reception path of the reflected wave are close to each other so that they can be integrated.

In addition, the light amount sensor 31 detects an illumination environment of a road and changes an obstacle detection area. When the brightness of the road is good, visual recognition of an obstacle is good, so that the obstacle detection area is narrowed to reduce frequent detection operation. In addition, when the brightness of the road is dark, the visual perception of the obstacle is poor, so that the obstacle detection area is set wide to recognize and prepare for the obstacle in advance. That is, when the brightness of the road is detected most brightly from the light amount sensor 31, as shown in FIG. 4, the reflector driver 24 sets the obstacle detection area by rotating the reflector 23 left and right at a predetermined angle of 6 °. do. At this time, the set detection area can satisfactorily detect three lane widths in front of 100 meters. In addition, when the brightness of the road is darkest detected from the light amount sensor 31, the controller 40 controls the reflector driver 24 to rotate the reflector 23 left and right at a predetermined angle of 12 ° to set an obstacle detection area. do. At this time, the set detection area can detect the six lane widths well in front of 100 meters. That is, the information about the intersection vehicle, the vehicle next to the lane, and other obstacles can be recognized in advance and prepared. In addition, the rotation angle of the reflector 23 is changed to a predetermined size according to the brightness of the road detected by the light amount sensor 31. In this example, the rotation angle is varied from 6 ° to 12 ° by a predetermined size.

Hereinafter, the operation of the scanning laser radar of the collision avoidance warning apparatus for a vehicle according to the present invention will be described with reference to the above-described components.

When the collision avoidance alarm device of the vehicle is operated, the controller 40 checks whether there is an abnormality of the system and then initializes the drive by the reflector driving unit 23 implemented as a stepping motor. That is, when the reflector 23 is rotated, the laser beam transmitted from the transmitter 21 changes its reflection angle according to the rotation of the reflector 23. At this time, the reflected laser beam can be detected at a predetermined angle. When the position sensor 29 detects the laser beam, the position detector 29 finds an initial position of the reflector driving unit 24.

Subsequently, the controller 40 rotates the reflector 23 to the left and right at a predetermined angle based on the initial position of the reflector driving unit 24 to detect an obstacle. That is, the control unit 40 rotates the rotation angle of the reflector by 0.02 °, and reflector driving unit 24 during the time T (T = 2R / speed, R is the maximum detection distance) at which the transmitted laser beam can be received again. Stops) to detect the presence of reflected waves and repeats it in the detection zone set according to the road's illumination environment.

The laser beam transmitted forward is reflected when it meets an obstacle, and the reflected laser beam is captured by the receiver 28 to check whether there is an obstacle in front of the laser beam. That is, the reflected wave and the light wave introduced into the collision avoidance alarm device are filtered by a band pass filter composed of the protective glass 25 and the reflector 23 and then bent at a predetermined angle by the reflector 23 to be transmitted to the light receiving lens 27. do. Therefore, by receiving the laser beam focused at the light transmitting lens 27 at the light receiver 28, it is possible to detect the presence or absence of an obstacle. In addition, the controller 40 determines whether the laser beam transmitted from the transmitter 21 is compared with the reference voltage level by converting and amplifying the received laser beam into an electrical signal and amplifying the received laser beam. By measuring the time until the beam is received by the receiver 28, the distance to the obstacle is calculated and the result is alerted according to the condition.

When the laser beam transmitted forward is reflected by the contaminant 30 adsorbed on the surface of the protective glass 25 into the collision avoidance alarm device and received by the light receiver 28, the controller 40 compares with the reference voltage level. It is judged whether the laser beam transmitted from the transmitter 21 is measured, and the time until the transmitted laser beam is received by the receiver 28 after determination is measured, and the measurement time is several ten centimeters (50 cm in the present invention). When it is determined that the reflection has returned from the distance of the example), it is determined that this is caused by the pollutant 30 and transmits an error signal to inform the driver of the contamination.

As described in detail above, according to the present invention, the number of parts and the manufacturing cost can be reduced by constructing the band pass filter using the protective glass and the reflector.

In addition, by using one reflector, the protective glass on the light transmitting side and the light receiving side can be realized as one, thereby reducing manufacturing costs and increasing the reliability of the device.

In addition, it is possible to set the initial position of the reflector driving unit satisfactorily through the position sensor.

In addition, the obstacle detection area may be changed according to the road illumination environment, so that obstacle detection information may be well provided.

Claims (8)

A transmitter for generating and transmitting light waves of a specific frequency band, a reflector reflecting the light waves transmitted from the transmitter in a direction to detect an obstacle, a driver for rotating the reflector at a specific angle, and reflecting the light from the reflectors The received light wave is reflected on the obstacle and is returned on the reflector to receive and receive the light from the reflector, the light wave reflected from the reflector and transmitted, and the light wave reflected from the reflector and received from the dirt coming from the outside A protective glass for blocking the light, a light amount sensor for measuring an external illuminance, and an optical wave transmitted from the transmitter to reflect the obstacle and return the light to the receiver to calculate a distance to the obstacle And perform alarm operation as necessary, And a control unit for varying the obstacle detection area by rotating the reflection angle of the reflector by controlling the driving unit in accordance with an external illuminance amount read from the light source. The method of claim 1, Scanning laser radar, characterized in that the transmitter and the receiver is provided on the same side to perform the transmission and reception operation through one reflector. The method of claim 1, The protective glass passes light waves only below a predetermined frequency band among the light waves transmitted through the reflector by reflecting the obstacle, and the reflector reflects light waves only above a predetermined frequency band among the light waves passing through the protective glass. A scanning laser radar, characterized by reflecting toward a photon side to form a band pass filter. The method of claim 1, wherein the driving unit for driving the reflector Scanning laser radar, characterized in that by setting the initial position when the reflected light wave is detected by the position detection unit by reflecting the light wave generated by the transmitter by rotating the reflector at a predetermined angle during the initial driving. The method of claim 1, wherein the control unit Scanning laser radar, characterized in that for controlling the rotation angle of the reflector so as to be inversely proportional to the amount of light read from the light amount sensor. The method of claim 5, Scanning laser radar, characterized in that the rotation angle of the reflector is controlled in the range of 6 ° to 12 °. The method of claim 1, wherein the control unit The laser beam received by the light receiver is converted into an electrical signal and amplified to compare the amplified electric signal with a reference voltage level to determine whether the light is received. If it is determined that the light is received, the laser beam transmitted by the transmitter is the light receiver. Scanning laser radar, characterized in that to calculate the distance to the obstacle by measuring the time it takes to receive light. The method of claim 7, wherein the control unit Measuring the time it takes for the laser beam transmitted from the transmitter to receive the receiver, and if it is determined that the measured time is shorter than the preset time, it is determined that the protective glass is contaminated to perform an alarm operation Scanning laser radar.

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