CN209992664U

CN209992664U - Stray light suppression circuit of laser radar

Info

Publication number: CN209992664U
Application number: CN201920401239.8U
Authority: CN
Inventors: 疏达; 李�远; 张海武; 梁炳寅
Original assignee: Beixing (beijing) Photon Technology Co Ltd
Current assignee: Beixing (beijing) Photon Technology Co Ltd; Benewake Beijing Co Ltd
Priority date: 2019-03-27
Filing date: 2019-03-27
Publication date: 2020-01-24
Anticipated expiration: 2029-03-27

Abstract

The application relates to a laser radar circuit, especially relates to a stray light suppression circuit of laser radar. The device comprises a trigger signal module, a gain control module and an amplification module which are in signal connection, wherein the trigger signal module is used for sending a trigger signal to trigger the gain control module to work; the gain control module is used for controlling the signal gain of the amplification module, reducing the signal gain of the amplification module after receiving the trigger signal, and recovering the signal gain of the amplification module after a set time; the amplification module is used for carrying out signal gain on the laser radar receiving signals. According to the application, the gain control module is used for controlling the signal gain of the amplification module, and after the trigger signal is received, the signal gain of the amplification module is reduced firstly, so that the receiving module cannot receive the stray light signal. After the set time, the signal gain of the amplifying module is recovered, the reflected light signal is normally received, and the stray light is restrained.

Description

Stray light suppression circuit of laser radar

Technical Field

The utility model discloses the application relates to the laser radar field especially relates to a stray light suppression circuit of laser radar.

Background

The laser radar has the advantages of small volume, high resolution, strong anti-interference capability and the like, can be used for speed measurement, distance measurement, accurate tracking, guidance, navigation and the like, and is widely applied in the fields of unmanned automobiles, unmanned airplanes, 3D printing, VR/AR and the like.

The laser radar optical system is one of the main components of the laser radar, the basic function of the system is to change the laser beam emitted by the laser into the irradiation beam required by the laser radar, irradiate the laser onto the target, and receive the echo signal reflected from the target, in the process, because of the light leakage of the optical system, the residual reflection of the surface of the optical element and the residual reflection of the non-optical surface in the optical system, the stray light can appear, the existence of the stray light can generate great influence on the final measurement precision, in order to eliminate the stray light, the technicians in the field generally adopt the structural component to isolate the emitting light source, and combine the light absorbing material to absorb the stray light, thereby reducing the crosstalk generated by the stray light generated by the light source to the receiving module, the method provides high requirements on the processing precision and the assembly precision of the light path design and the structural component, but the size of the entire light engine can also be large.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides a stray light suppression circuit of a laser radar, and solves the problem of stray light from the aspect of circuit control.

To achieve the purpose, the application embodiment of the present invention adopts the following technical solutions:

on one hand, the stray light suppression circuit of the laser radar comprises a trigger signal module, a gain control module and an amplification module which are connected by signals,

the trigger signal module is used for sending out a trigger signal to trigger the gain control module to work;

the gain control module is used for controlling the signal gain of the amplification module, reducing the signal gain of the amplification module after receiving the trigger signal, and recovering the signal gain of the amplification module after a set time;

the amplification module is used for carrying out signal gain on the laser radar receiving signals.

In a possible implementation manner, the gain control module generates a gain control signal, and the amplitude of the gain control signal rises or falls, so as to control the amplification module to reduce the signal gain.

In one possible implementation, the amplitude of the gain control signal is increased or decreased to be non-linear.

In one possible implementation, the amplitude of the gain control signal rises or falls by 10-80%.

In one possible implementation, the amplitude of the gain control signal rises or falls by 40-60%.

In a possible implementation, the signal gain of the amplifying module is reduced to below 300 mV.

In a possible implementation, the signal gain of the amplifying module is reduced to below 200 mV.

In one possible implementation, the set time is 200 ns and 1000 ns.

In one possible implementation, the set time is 400-800 ns.

In a possible implementation manner, the trigger signal module is an FPGA chip, the gain control module is an RC circuit, and the amplification module is an AD chip.

According to the embodiment of the application, the gain control module is used for controlling the signal gain of the amplifying module, and after the trigger signal is received, the signal gain of the amplifying module is reduced firstly, so that the receiving module cannot receive the stray light signal. After the set time, the signal gain of the amplifying module is recovered, the reflected light signal is normally received, and the stray light is restrained.

Drawings

Fig. 1 is a schematic diagram of an embodiment of the present application.

In the figure: 1. a trigger signal module; 2. a gain control module; 3. an amplifying module; 4. a trigger signal; 5. a gain control signal; 6. receiving a signal; 7. the amplified received signal.

Detailed Description

The technical scheme of the application is further explained by the specific implementation mode in combination with the attached drawings.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only partial embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It should be understood that the data so used may be interchanged under appropriate circumstances such that embodiments of the application described herein may be used. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, apparatus, article, or device that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or device.

The embodiment of the application.

As shown in FIG. 1, a stray light suppression circuit for laser radar comprises a trigger signal module 1, a gain control module 2 and an amplification module 3 which are connected by signals,

the trigger signal module 1 is used for sending out a trigger signal 4 to trigger the gain control module 2 to work;

the gain control module 2 is used for controlling the signal gain of the amplification module 3, reducing the signal gain of the amplification module 3 after receiving the trigger signal 4, and recovering the signal gain of the amplification module 3 after a set time;

the amplifying module 3 is used for performing signal gain on the laser radar receiving signal 6 and amplifying the laser radar receiving signal into an amplified receiving signal 7.

This application controls the signal gain of amplification module 3 through gain control module 2, after receiving trigger signal 4, reduces amplification module 3's signal gain earlier, and amplification module 3's signal gain is less this moment, and the signal gain that stray light signal received is little, and its intensity is not enough to be received by laser radar's receiving arrangement. And in the process, the gain is reduced for the stray light signal, and the gain is carried out for the echo signal, so that the stray light is restrained and the echo signal can be normally received.

The gain control module 2 generates a gain control signal 5, and the amplitude of the gain control signal 5 rises or falls, so as to control the amplification module 3 to reduce the signal gain.

The signal gain of the amplifying module 3 has two control modes, one is to decrease the signal gain along with the rise of the amplitude of the gain control signal 5, and the other is to decrease the signal gain along with the fall of the amplitude of the gain control signal 5.

The amplitude of the gain control signal 5 rises or falls to be nonlinear.

Because the gain control module 2 selects an RC circuit, the generated RC level curve is non-linear.

The amplitude of the gain control signal 5 rises or falls by 10-80%.

The amplitude of the gain control signal 5 rises or falls by 40-60%.

This amplitude variation ensures that the amplification module 3 can accurately receive the gain control signal 5 and reduce the signal gain according to the gain control signal 5.

The signal gain of the amplifying module 3 is reduced to below 300 mV.

The signal gain of the amplifying module 3 is reduced to below 200 mV.

According to the requirement of the laser radar receiving device on the signal intensity, the signal gain of the amplifying module 3 is reduced to be below 200mV, so that the stray light signal can be ensured to be not received because the intensity is too low.

The setting time is 200-1000 ns.

With this time, the range of the laser radar is 30m-150 m. The requirement of maximum measuring distance is met.

The setting time is 400-800 ns.

With this time, the range of the laser radar is 60m to 120 m. And the requirement of accurate distance measurement is met.

The trigger signal module 1, the gain control module 2 and the amplifying module 3 are as follows: the trigger signal module 1 is an FPGA chip, the gain control module 2 is an RC circuit, and the amplifying module 3 is an AD chip.

The above devices are all prior art.

The technical principles of the present application have been described above in connection with specific embodiments. The description is made for the purpose of illustrating the principles of the present application and is not to be construed in any way as limiting the scope of the application. Based on the explanations herein, those skilled in the art will be able to conceive of other embodiments of the present application without inventive effort, which shall fall within the scope of the present application.

Claims

1. A stray light suppression circuit of a laser radar is characterized by comprising a trigger signal module, a gain control module and an amplification module which are in signal connection,

2. The lidar stray light suppression circuit according to claim 1, wherein the gain control module generates a gain control signal, and the amplitude of the gain control signal rises or falls to control the amplification module to reduce the signal gain.

3. The lidar stray light suppression circuit of claim 2, wherein the gain control signal is non-linear in magnitude.

4. The lidar stray light suppression circuit of claim 3, wherein the gain control signal increases or decreases in amplitude by 10-80%.

5. The lidar stray light suppression circuit of claim 4, wherein the amplitude of the gain control signal is increased or decreased by 40-60%.

6. The lidar stray light suppression circuit of claim 5, wherein a signal gain of the amplification module is reduced to below 300 mV.

7. The lidar stray light suppression circuit of claim 6, wherein a signal gain of the amplification module is reduced to below 200 mV.

8. The circuit as claimed in claim 7, wherein the setting time is 200 ns and 1000 ns.

9. The circuit as claimed in claim 8, wherein the setting time is 400-800 ns.

10. The laser radar stray light suppression circuit according to claim 9, wherein the trigger signal module is an FPGA chip, the gain control module is an RC circuit, and the amplification module is an AD chip.