阅读说明：本技术 计算机存储介质、激光雷达系统及其同步方法 (Computer storage medium, laser radar system and synchronization method thereof ) 是由 沈文江 周鹏 李小光 史庆刚 于 2020-12-24 设计创作，主要内容包括：本发明提供了一种计算机存储介质、激光雷达系统及其同步方法,激光雷达系统包括激光源、第一MEMS微镜、第二MEMS微镜以及探测器,所述同步方法包括：将第一MEMS微镜和第二MEMS微镜平行放置；实时获取第一MEMS微镜、第二MEMS微镜的反馈信号；判断第二MEMS微镜的反馈信号与第一MEMS微镜的反馈信号是否相同；若第二MEMS微镜的反馈信号与第一MEMS微镜的反馈信号不同,则调节第一MEMS微镜、第二MEMS微镜的驱动信号,以使得第二MEMS微镜的反馈信号与第一MEMS微镜的反馈信号相同。本发明提供的同步方法能够实现回光脉冲的指向性接收,简化系统结构、降低成本的同时提升了探测器接收到的信号的信噪比。(The invention provides a computer storage medium, a laser radar system and a synchronization method thereof, wherein the laser radar system comprises a laser source, a first MEMS micro-mirror, a second MEMS micro-mirror and a detector, and the synchronization method comprises the following steps: placing a first MEMS micro-mirror and a second MEMS micro-mirror in parallel; acquiring feedback signals of the first MEMS micro-mirror and the second MEMS micro-mirror in real time; judging whether the feedback signal of the second MEMS micro-mirror is the same as the feedback signal of the first MEMS micro-mirror; and if the feedback signal of the second MEMS micro-mirror is different from the feedback signal of the first MEMS micro-mirror, adjusting the driving signals of the first MEMS micro-mirror and the second MEMS micro-mirror so that the feedback signal of the second MEMS micro-mirror is the same as the feedback signal of the first MEMS micro-mirror. The synchronization method provided by the invention can realize the directional reception of the return light pulse, simplify the system structure, reduce the cost and simultaneously improve the signal-to-noise ratio of the signal received by the detector.)

1. A synchronization method of a laser radar system is characterized in that the laser radar system comprises a laser source, a first MEMS micro-mirror, a second MEMS micro-mirror and a detector, laser emitted by the laser source sequentially passes through the first MEMS micro-mirror, a detected object and the second MEMS micro-mirror and then is received by the detector, and the synchronization method comprises the following steps:

placing the first MEMS micro-mirror and the second MEMS micro-mirror in parallel;

acquiring feedback signals of the first MEMS micro-mirror and the second MEMS micro-mirror in real time;

judging whether the feedback signal of the second MEMS micro-mirror is the same as the feedback signal of the first MEMS micro-mirror;

and if the feedback signal of the second MEMS micro-mirror is different from the feedback signal of the first MEMS micro-mirror, adjusting the driving signals of the first MEMS micro-mirror and the second MEMS micro-mirror so that the feedback signal of the second MEMS micro-mirror is the same as the feedback signal of the first MEMS micro-mirror.

2. The synchronization method as claimed in claim 1, wherein the adjusting the driving signals of the first and second MEMS micro-mirrors so that the feedback signal of the second MEMS micro-mirror is the same as the feedback signal of the first MEMS micro-mirror comprises:

acquiring working modes of the first MEMS micro-mirror and the second MEMS micro-mirror;

if the working modes of the first MEMS micro-mirror and the second MEMS micro-mirror are in a resonance state, judging whether the phase difference between the feedback signal of the first MEMS micro-mirror and the driving signal of the first MEMS micro-mirror is a preset value or not;

and if the phase difference between the feedback signal of the first MEMS micro-mirror and the driving signal of the first MEMS micro-mirror is a preset value, adjusting the driving signals of the first MEMS micro-mirror and the second MEMS micro-mirror so as to enable the feedback signal of the second MEMS micro-mirror to be the same as the feedback signal of the first MEMS micro-mirror.

3. The synchronization method according to claim 2, wherein if the phase difference between the feedback signal of the first MEMS micro-mirror and the driving signal of the first MEMS micro-mirror is not a predetermined value, before adjusting the driving signals of the first and second MEMS micro-mirrors, the synchronization method further comprises:

adjusting a frequency of a driving signal of the first MEMS micro-mirror such that a phase difference of a feedback signal of the first MEMS micro-mirror and the driving signal of the first MEMS micro-mirror is a predetermined value.

4. The synchronization method as claimed in claim 2, wherein adjusting the driving signals of the first and second MEMS micro-mirrors comprises:

and adjusting the amplitude of the driving signal of the first MEMS micro-mirror and adjusting the amplitude, frequency and phase of the driving signal of the second MEMS micro-mirror.

5. The synchronization method as claimed in claim 2, wherein if the operation mode of the first and second MEMS micro-mirrors is quasi-static, the amplitude and scanning period of the driving signal of the first/second MEMS micro-mirror are adjusted so that the feedback signal of the second MEMS micro-mirror is the same as the feedback signal of the first MEMS micro-mirror.

6. The synchronization method according to claim 4 or 5, wherein adjusting the amplitude of the driving signal of the first/second MEMS micro-mirror comprises:

acquiring a voltage value and a resistance value of the first MEMS micro-mirror/the second MEMS micro-mirror;

obtaining the current environment temperature according to the corresponding relation between the resistance and the temperature of the first MEMS micro-mirror/the second MEMS micro-mirror;

obtaining a target voltage value of the first MEMS micro-mirror/the second MEMS micro-mirror at the current environment temperature and the preset deflection angle according to the corresponding relation of the temperature and the voltage of the first MEMS micro-mirror/the second MEMS micro-mirror at the preset deflection angle;

judging whether the voltage value of the first MEMS micro-mirror/the second MEMS micro-mirror is equal to the target voltage value of the first MEMS micro-mirror/the second MEMS micro-mirror at the current ambient temperature and the preset deflection angle;

if the voltage value of the first MEMS micro-mirror/the second MEMS micro-mirror is not equal to the target voltage value of the first MEMS micro-mirror/the second MEMS micro-mirror at the current environment temperature and the preset deflection angle, adjusting the amplitude of the driving signal of the first MEMS micro-mirror/the second MEMS micro-mirror so as to enable the voltage value of the first MEMS micro-mirror/the second MEMS micro-mirror to be equal to the target voltage value of the first MEMS micro-mirror/the second MEMS micro-mirror at the current environment temperature and the preset deflection angle.

7. The synchronization method according to claim 6, wherein the correspondence of the resistance of the first/second MEMS micro-mirrors to the temperature is obtained by:

acquiring resistance values of the first MEMS micro-mirror/the second MEMS micro-mirror at a plurality of environmental temperatures;

calibrating the multiple environmental temperatures and the resistance values of the first MEMS micro-mirror/the second MEMS micro-mirror at the multiple environmental temperatures to obtain the corresponding relation between the resistance values and the temperatures of the first MEMS micro-mirror/the second MEMS micro-mirror.

8. The synchronization method according to claim 6, wherein the correspondence of the temperature and the voltage of the first/second MEMS micro-mirror at a predetermined deflection angle is obtained by:

acquiring voltage values of a first MEMS micro-mirror/a second MEMS micro-mirror at a plurality of environmental temperatures at a preset deflection angle;

calibrating the multiple environmental temperatures and the voltage values of the first MEMS micro-mirror/the second MEMS micro-mirror under the multiple environmental temperatures to obtain the corresponding relation between the voltage and the temperature of the first MEMS micro-mirror/the second MEMS micro-mirror.

9. The laser radar system is characterized by comprising a laser source, a first MEMS micro-mirror, a second MEMS micro-mirror and detectors, wherein the number of the laser sources is one or more, the number of the first MEMS micro-mirror, the number of the second MEMS micro-mirror and the number of the detectors are equal to the number of the laser sources, or the number of the laser sources is multiple, the number of the detectors is equal to the number of the laser sources, and the number of the first MEMS micro-mirror and the number of the second MEMS micro-mirror are one.

10. A computer storage medium having a computer program stored therein, which when read and executed by one or more processors implements the synchronization method of a lidar system according to any of claims 1 to 8.

Technical Field

The invention relates to the technical field of laser radars, in particular to a computer storage medium, a laser radar system and a synchronization method thereof.

Background

Automobile intellectualization (including intelligent assistant driving and automatic driving) is a comprehensive system integrating environment perception, planning decision and multi-level assistant driving functions, is an inevitable trend of future automobile development, and has become a research hotspot in the automobile field in the world and a new power for the growth of the automobile industry. The environment perception sensors used in the automobile intellectualization mainly comprise the following sensors: the system comprises an image sensor, a laser radar, a millimeter wave radar and an ultrasonic radar, wherein the laser radar can directly acquire environment three-dimensional information, and is considered to be one of sensors necessary for realizing automobile intellectualization, but is also the sensor with the lowest maturity in the sensors at present.

At present, the laser radar adopts a mechanical turntable form, the assembly precision requirement of the laser radar is very high, highly rigorous opto-electro-mechanical system calibration is required, the price is high, the assembly process is complex, the productivity is low, large-scale mass production performance required by an automobile market is not achieved, and the service life and the stability of the mechanical turntable type laser radar system working on an automobile can be reduced due to the vibration and abrasion problems of mechanical parts such as a turntable and the like, so that the mechanical turntable type laser radar is difficult to pass through automobile specification authentication.

Solid state lidar, which has the primary purpose of abandoning machinery, is increasingly being considered as the most likely vehicle-scale lidar solution to subvert the traditional lidar technology framework. The pulse scanning scheme of the solid-state laser radar comprises the technical schemes of Optical Phased Array (OPA), MEMS scanning, area array imaging (Flash) and the like, wherein the technical scheme of the MEMS laser radar utilizes an MEMS micro-mirror to scan optical pulses, so that the design of a laser radar system is simplified, and meanwhile, the batch characteristic of a micro-processing semiconductor process is utilized, so that the requirements of low price and mass production of the laser radar are expected to be met.

The commonly used structure of the existing MEMS lidar includes: 1) at a pulse transmitting end, the MEMS micro-mirror scans laser pulses point by point to realize the transmission of the pulses, and at a pulse receiving end, return light pulses within a visual field range are received point by point through a wide-angle optical lens, so that the defect that the detector needs to adopt an area array detector, and because the wide-angle optical lens receives the return light pulses, the background light noise is large, and the signal-to-noise ratio is low; 2) the method has the advantages that the MEMS micro-mirror scans laser pulses point by point at a pulse transmitting end to realize the transmission of the pulses, and the return light pulses are reflected by the same MEMS micro-mirror at a pulse receiving end by utilizing the principle that an optical path is reversible.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a laser radar system, a synchronization method thereof and a computer storage medium, which can realize the directional reception of return light pulses, simplify the system structure, reduce the cost and simultaneously improve the signal-to-noise ratio of signals received by a detector.

The specific technical scheme provided by the invention is as follows: the laser radar system comprises a laser source, a first MEMS micro-mirror, a second MEMS micro-mirror and a detector, wherein laser emitted by the laser source sequentially passes through the first MEMS micro-mirror, a detected object and the second MEMS micro-mirror and then is received by the detector, and the synchronization method comprises the following steps:

placing the first MEMS micro-mirror and the second MEMS micro-mirror in parallel;

acquiring feedback signals of the first MEMS micro-mirror and the second MEMS micro-mirror in real time;

judging whether the feedback signal of the second MEMS micro-mirror is the same as the feedback signal of the first MEMS micro-mirror;

and if the feedback signal of the second MEMS micro-mirror is different from the feedback signal of the first MEMS micro-mirror, adjusting the driving signals of the first MEMS micro-mirror and the second MEMS micro-mirror so that the feedback signal of the second MEMS micro-mirror is the same as the feedback signal of the first MEMS micro-mirror.

Further, the adjusting the driving signals of the first MEMS micro-mirror and the second MEMS micro-mirror to make the feedback signal of the second MEMS micro-mirror the same as the feedback signal of the first MEMS micro-mirror includes:

acquiring working modes of the first MEMS micro-mirror and the second MEMS micro-mirror;

if the working modes of the first MEMS micro-mirror and the second MEMS micro-mirror are in a resonance state, judging whether the phase difference between the feedback signal of the first MEMS micro-mirror and the driving signal of the first MEMS micro-mirror is a preset value or not;

and if the phase difference between the feedback signal of the first MEMS micro-mirror and the driving signal of the first MEMS micro-mirror is a preset value, adjusting the driving signals of the first MEMS micro-mirror and the second MEMS micro-mirror so as to enable the feedback signal of the second MEMS micro-mirror to be the same as the feedback signal of the first MEMS micro-mirror.

Further, if the phase difference between the feedback signal of the first MEMS micro-mirror and the driving signal of the first MEMS micro-mirror is not a predetermined value, before adjusting the driving signals of the first MEMS micro-mirror and the second MEMS micro-mirror, the synchronization method further comprises:

adjusting a frequency of a driving signal of the first MEMS micro-mirror such that a phase difference of a feedback signal of the first MEMS micro-mirror and the driving signal of the first MEMS micro-mirror is a predetermined value.

Further, adjusting the driving signals of the first MEMS micro-mirror and the second MEMS micro-mirror specifically includes:

and adjusting the amplitude of the driving signal of the first MEMS micro-mirror and adjusting the amplitude, frequency and phase of the driving signal of the second MEMS micro-mirror.

Further, if the working modes of the first MEMS micro-mirror and the second MEMS micro-mirror are quasi-static, the amplitude and the scanning period of the driving signal of the first MEMS micro-mirror/the second MEMS micro-mirror are adjusted so that the feedback signal of the second MEMS micro-mirror is the same as the feedback signal of the first MEMS micro-mirror.

Further, adjusting the amplitude of the driving signal of the first MEMS micro-mirror/the second MEMS micro-mirror specifically comprises:

acquiring a voltage value and a resistance value of the first MEMS micro-mirror/the second MEMS micro-mirror;

obtaining the current environment temperature according to the corresponding relation between the resistance and the temperature of the first MEMS micro-mirror/the second MEMS micro-mirror;

obtaining a target voltage value of the first MEMS micro-mirror/the second MEMS micro-mirror at the current environment temperature and the preset deflection angle according to the corresponding relation of the temperature and the voltage of the first MEMS micro-mirror/the second MEMS micro-mirror at the preset deflection angle;

judging whether the voltage value of the first MEMS micro-mirror/the second MEMS micro-mirror is equal to the target voltage value of the first MEMS micro-mirror/the second MEMS micro-mirror at the current ambient temperature and the preset deflection angle;

if the voltage value of the first MEMS micro-mirror/the second MEMS micro-mirror is not equal to the target voltage value of the first MEMS micro-mirror/the second MEMS micro-mirror at the current environment temperature and the preset deflection angle, adjusting the amplitude of the driving signal of the first MEMS micro-mirror/the second MEMS micro-mirror so as to enable the voltage value of the first MEMS micro-mirror/the second MEMS micro-mirror to be equal to the target voltage value of the first MEMS micro-mirror/the second MEMS micro-mirror at the current environment temperature and the preset deflection angle.

Further, the corresponding relation between the resistance and the temperature of the first MEMS micro-mirror/the second MEMS micro-mirror is obtained by the following steps:

acquiring resistance values of the first MEMS micro-mirror/the second MEMS micro-mirror at a plurality of environmental temperatures;

calibrating the multiple environmental temperatures and the resistance values of the first MEMS micro-mirror/the second MEMS micro-mirror at the multiple environmental temperatures to obtain the corresponding relation between the resistance values and the temperatures of the first MEMS micro-mirror/the second MEMS micro-mirror.

Further, the correspondence between the temperature and the voltage of the first/second MEMS micro-mirror at a predetermined deflection angle is obtained by:

acquiring voltage values of a first MEMS micro-mirror/a second MEMS micro-mirror at a plurality of environmental temperatures at a preset deflection angle;

calibrating the multiple environmental temperatures and the voltage values of the first MEMS micro-mirror/the second MEMS micro-mirror under the multiple environmental temperatures to obtain the corresponding relation between the voltage and the temperature of the first MEMS micro-mirror/the second MEMS micro-mirror.

The invention also provides a laser radar system which comprises one or more laser sources, the first MEMS micro-mirror, the second MEMS micro-mirror and the detectors, or the laser sources, the detectors and the first MEMS micro-mirror and the second MEMS micro-mirror are equal in number, or the number of the laser sources is multiple, the number of the detectors is equal to that of the laser sources, and the number of the first MEMS micro-mirror and the second MEMS micro-mirror is one.

The invention also provides a computer storage medium having stored thereon a computer program which, when read and executed by one or more processors, implements a method of synchronization of a lidar system as defined in any of the preceding claims.

The laser radar system provided by the invention comprises a first MEMS micro-mirror and a second MEMS micro-mirror, wherein the second MEMS micro-mirror is added at a receiving end and controls the first MEMS micro-mirror and the second MEMS micro-mirror to work synchronously, so that a transmitting light path and a receiving light path of the laser radar system are mutually independent, and the second MEMS micro-mirror can point to receive a laser beam transmitted by the first MEMS micro-mirror in real time.

Drawings

The technical solution and other advantages of the present invention will become apparent from the following detailed description of specific embodiments of the present invention, which is to be read in connection with the accompanying drawings.

Fig. 1 is a schematic structural diagram of a laser radar system according to a first embodiment of the present application;

fig. 2 is a schematic flowchart illustrating a synchronization method of a laser radar system according to a first embodiment of the present disclosure;

FIG. 3 is a diagram illustrating the relationship between the amplitude and the phase of the MEMS micro-mirror in the resonant state;

FIG. 4 is a scanning schematic diagram of the MEMS micro-mirror;

FIG. 5 shows the driving signals of the MEMS micromirror in quasi-static state;

fig. 6 is a schematic diagram of a synchronization control apparatus of a laser radar system according to a first embodiment of the present application;

FIG. 7 is a block diagram of a computer storage medium and a processor according to an embodiment of the present disclosure;

fig. 8 is a schematic structural diagram of a laser radar system according to a second embodiment of the present application;

fig. 9 is a schematic structural diagram of a laser radar system according to a third embodiment of the present application.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the specific embodiments set forth herein. Rather, these embodiments are provided to explain the principles of the invention and its practical application to thereby enable others skilled in the art to understand the invention for various embodiments and with various modifications as are suited to the particular use contemplated. In the drawings, like reference numerals will be used to refer to like elements throughout.

Example one

The first MEMS micro-mirror 2 and the second MEMS micro-mirror 3 in this embodiment are both two-dimensional scanning micro-mirrors, the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3 both comprise a fast axis and a slow axis, wherein the working frequency of the fast axis is higher and usually works in a resonance state, the working frequency of the slow axis is lower and usually works in a quasi-static state or a resonance state, in this embodiment, the method for synchronizing the fast axis of the first MEMS micromirror 2/the second MEMS micromirror 3 in the resonant state is the same as the method for synchronizing the slow axis of the first MEMS micromirror 2/the second MEMS micromirror 3 in the resonant state, and the method for synchronizing the fast axis of the first MEMS micromirror 2/the second MEMS micromirror 3 in the resonant state is defined as the first MEMS micromirror 2/the second MEMS micromirror 3 working in the resonant state, and the slow axis of the first MEMS micromirror 2/the second MEMS micromirror 3 in the quasi-static state is defined as the first MEMS micromirror 2/the second MEMS micromirror 3 working in the quasi-static state.

Referring to fig. 1-2, the lidar system of the present embodiment includes a laser source 1, a first MEMS micro-mirror 2, a second MEMS micro-mirror 3, and a detector 4. The laser source 1 is a light source of a laser radar system, a laser beam emitted by the laser source passes through the first MEMS micro-mirror 2 and then is incident on the detected object 5 and is reflected by the detected object 5 to the second MEMS micro-mirror 3, and the laser beam passing through the second MEMS micro-mirror 3 is received by the detector 4. The first MEMS micro-mirror 2 and the second MEMS micro-mirror 3 can scan in two directions to form an area array detection area.

Referring to fig. 3, the synchronization method of the laser radar system in the present embodiment includes the steps of:

s1, placing the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3 in parallel;

s2, acquiring feedback signals of the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3 in real time;

s3, judging whether the feedback signal of the second MEMS micro-mirror 3 is different from the feedback signal of the first MEMS micro-mirror 2; if the feedback signal of the second MEMS micro-mirror 3 is different from the feedback signal of the first MEMS micro-mirror 2, go to step S4;

s4, adjusting the driving signals of the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3 such that the feedback signal of the second MEMS micro-mirror 3 is the same as the feedback signal of the first MEMS micro-mirror 2.

In step S2, sensors are integrated on the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3, and feedback signals of the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3 can be obtained in real time through the sensors on the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3, specifically, piezoresistive sensors are integrated on the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3, and the feedback signals of the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3 can be obtained through the piezoresistive sensors. Here, the feedback signals of the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3 specifically refer to actual deflection angles of the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3.

Preferably, the performance parameters of the first MEMS micro-mirror 2 and the performance of the second MEMS micro-mirror 3 in this embodiment are consistent, wherein the performance parameters of the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3 include an operating frequency, a deflection angle, and the like, and the consistency between the performance parameters of the first MEMS micro-mirror 2 and the performance of the second MEMS micro-mirror 3 means that the operating frequency of the first MEMS micro-mirror 2 is the same as the operating frequency of the second MEMS micro-mirror 3, and the deflection angle of the first MEMS micro-mirror 2 is the same as the deflection angle of the second MEMS micro-mirror 3.

In step S3, the difference between the feedback signal of the second MEMS micro-mirror 3 and the feedback signal of the first MEMS micro-mirror 2 indicates that the second MEMS micro-mirror 3 and the first MEMS micro-mirror 2 do not work synchronously and the driving signals of the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3 need to be adjusted; the feedback signal of the second MEMS micro-mirror 3 is the same as the feedback signal of the first MEMS micro-mirror 2, that is, the actual deflection angles of the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3 are the same, which means that the second MEMS micro-mirror 3 and the first MEMS micro-mirror 2 work synchronously without adjusting the driving signals of the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3.

In step S4, adjusting the driving signals of the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3 to make the feedback signal of the second MEMS micro-mirror 3 the same as the feedback signal of the first MEMS micro-mirror 2 includes:

s41, acquiring the working modes of the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3, and if the working modes of the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3 are in a resonance state, entering the step S42; if the operation mode of the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3 is quasi-static, go to step S45;

s42, determining whether the phase difference between the feedback signal of the first MEMS micro-mirror 2 and the driving signal of the first MEMS micro-mirror 2 is a predetermined value, if the phase difference between the feedback signal of the first MEMS micro-mirror 2 and the driving signal of the first MEMS micro-mirror 2 is not the predetermined value, proceeding to S43, and if the phase difference between the feedback signal of the first MEMS micro-mirror 2 and the driving signal of the first MEMS micro-mirror 2 is the predetermined value, proceeding to S44;

s43, adjusting the frequency of the driving signal of the first MEMS micro-mirror 2 so that the phase difference between the feedback signal of the first MEMS micro-mirror 2 and the driving signal of the first MEMS micro-mirror 2 is a predetermined value, and proceeding to step S44;

s44, adjusting the driving signals of the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3 such that the feedback signal of the second MEMS micro-mirror 3 is the same as the feedback signal of the first MEMS micro-mirror 2.

S45, adjusting the amplitude and the scanning period of the driving signal of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3, so that the feedback signal of the second MEMS micro-mirror 3 is the same as the feedback signal of the first MEMS micro-mirror 2.

In step S41, the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3 have different operation modes and different adjustment modes of the corresponding driving signals.

In step S42, during the actual operation, the resonant frequency of the first MEMS micro-mirror 2 changes due to the influence of the operating environment, and the frequency of the driving signal of the first MEMS micro-mirror 2 needs to be changed continuously to maintain the operating mode at the resonant state. When the frequency of the driving signal of the first MEMS micro-mirror 2 is near its resonant frequency, the frequency of the feedback signal of the first MEMS micro-mirror 2 is the same as the frequency of the driving signal of the first MEMS micro-mirror 2, and there is a phase difference between the feedback signal of the first MEMS micro-mirror 2 and the driving signal of the first MEMS micro-mirror 2, wherein the phase difference is between 0 ° and 180 °, as shown in fig. 4.

When the phase difference between the feedback signal of the first MEMS micro-mirror 2 and the driving signal of the first MEMS micro-mirror 2 is a predetermined value, the frequency of the driving signal of the first MEMS micro-mirror 2 is equal to the resonant frequency of the first MEMS micro-mirror 2, that is, whether the first MEMS micro-mirror 2 is in a resonant state can be determined by whether the phase difference between the feedback signal of the first MEMS micro-mirror 2 and the driving signal of the first MEMS micro-mirror 2 is a predetermined value, and preferably, the predetermined value in this embodiment is 90 °.

In step S43, when the phase difference between the feedback signal of the first MEMS micro-mirror 2 and the driving signal of the first MEMS micro-mirror 2 is not a predetermined value, the frequency of the driving signal of the first MEMS micro-mirror 2 needs to be adjusted until the phase difference between the feedback signal of the first MEMS micro-mirror 2 and the driving signal of the first MEMS micro-mirror 2 is a predetermined value to ensure that the first MEMS micro-mirror 2 operates in the resonant state.

The phase information in this embodiment is obtained by sensors integrated on the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3, in particular, by piezoresistive sensors integrated on the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3.

In step S44, after the first MEMS micro-mirror 2 is maintained in the resonant state, in order to achieve synchronization between the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3, it is necessary to adjust the driving signals of the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3, so that the feedback signal of the second MEMS micro-mirror 3 is the same as the feedback signal of the first MEMS micro-mirror 2, that is, the deflection angles of the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3 are the same, thereby ensuring that the second MEMS micro-mirror 3 and the first MEMS micro-mirror 2 work synchronously.

Preferably, since the fast axis of the first MEMS micro-mirror is already operated in the resonant state by adjusting the frequency of the driving signal of the first MEMS micro-mirror 2, in step S44, it is only necessary to adjust the amplitude of the driving signal of the first MEMS micro-mirror and to adjust the amplitude, frequency and phase of the driving signal of the second MEMS micro-mirror 3, so that the feedback signal of the second MEMS micro-mirror 3 is the same as the feedback signal of the first MEMS micro-mirror 2, i.e. the deflection angles of the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3 are the same.

The following describes how to adjust the driving signals of the first and second MEMS micro-mirrors 2 and 3 when the operating modes of the first and second MEMS micro-mirrors 2 and 3 are resonant states in detail by taking the driving signal of the fast axis of the first MEMS micro-mirror 2 as a sinusoidal signal as an example.

The driving signals of the fast axis of the first MEMS micro-mirror 2 are:

the feedback signals of the fast axis of the first MEMS micro-mirror 2 are:

the driving signals of the fast axis of the second MEMS micro-mirror 3 are:

the feedback signals of the fast axis of the second MEMS micro-mirror 3 are:

wherein, ω 1, ω₂Respectively representing the frequencies of the driving signals of the fast axes of the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3,initial phases of driving signals of fast axes of the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3, respectively, where ω 1 is ω 2 at the initial time;respectively, the phase difference between the feedback signal and the driving signal of the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3.

First, it is judgedWhether or not it is 90 deg., ifNot equal to 90 deg., the driving signal omega 1 of the first MEMS micro-mirror 2 is adjusted untilEqual to 90 °; then, the amplitude A of the driving signal of the first MEMS micro-mirror 2 is adjusted₁' amplitude A of the driving signal to the second MEMS micro-mirror 3₂', such that A₁’＝A₂', and adjusting the frequency ω of the driving signal of the second MEMS micro-mirror 3₂So that ω is₂＝ω₁And adjusting the phase of the driving signal of the second MEMS micro-mirror 3So thatSo that the feedback signal of the second MEMS micro-mirror 3 is the same as the feedback signal of the first MEMS micro-mirror 2, i.e. the deflection angle of the second MEMS micro-mirror 3 is the same as the deflection angle of the first MEMS micro-mirror 2.

Because the micro-mirror is in the quasi-static mode, the operating frequency of the micro-mirror is a fixed value and does not change with the change of the operating environment, time and other factors, if the operating mode of the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3 is quasi-static, in step S45, the amplitude and the scanning period of the driving signal of the first MEMS micro-mirror 2 or the second MEMS micro-mirror 3 are adjusted, so that the amplitude and the scanning period of the driving signal of the second MEMS micro-mirror 3 are the same as the amplitude and the scanning period of the driving signal of the first MEMS micro-mirror 2, and the feedback signal of the second MEMS micro-mirror 3 is the same as the feedback signal of the first MEMS micro-mirror 2, that is, the deflection angle of the second MEMS micro-mirror 3 is the same as the deflection angle of the.

The scanning tracks of the first MEMS micromirror 2 and the second MEMS micromirror 3 in this embodiment are in a raster scanning manner, as shown in fig. 4, each circle represents an image pixel, the laser beam emitted from the laser source 1 scans according to a preset scanning line and scanning sequence, fig. 4 shows that the scanning line in this embodiment is a horizontal line from left to right, i.e. the laser beam first scans from the first image pixel at the upper left corner of the first horizontal line, scans along a straight line to the right until the last image pixel at the upper right corner of the first horizontal line, then retraces to the second horizontal line below the first horizontal line to repeat the above process, and scans line by line continuously according to the preset scanning line and scanning sequence, wherein the scanning period of the driving signal of the first MEMS micromirror 2/the second MEMS micromirror 3 includes that the laser beam retraces from the last image pixel at the upper right corner of the upper left horizontal line to the upper left corner of the next horizontal line, and the scanning sequence is repeated, wherein the scanning The time interval of the first image pixel and the time interval from the first image pixel at the upper left corner of the last horizontal line to the last image pixel at the upper right corner of the last horizontal line, wherein the scanning period of the feedback signal of the second MEMS micro-mirror 3 is the same as the feedback signal of the first MEMS micro-mirror 2, that is, the time interval from the retrace of the feedback signal of the second MEMS micro-mirror 3 from the last image pixel at the upper right corner of the last horizontal line to the first image pixel at the upper left corner of the next horizontal line is equal to the time interval from the retrace of the feedback signal of the first MEMS micro-mirror 2 from the last image pixel at the upper right corner of the last horizontal line to the first image pixel at the upper left corner of the next horizontal line, and the time interval from the scanning of the feedback signal of the second MEMS micro-mirror 3 from the first image pixel at the upper left corner of the last horizontal line to the last image pixel at the upper right corner of the last horizontal line is equal to the feedback signal The time interval for the signal to scan from the first image pixel in the upper left corner of the last horizontal line to the last image pixel in the upper right corner of the last horizontal line is also equal.

Referring to fig. 5, fig. 5 shows a case where the driving signal of the first MEMS micromirror 2/the second MEMS micromirror 3 in the quasi-static mode in the present embodiment is a triangular waveform, where a represents the amplitude of the driving signal of the first MEMS micromirror 2/the second MEMS micromirror 3, and the 0-T1 period represents the time interval from the last image pixel in the upper right corner of the last horizontal line retracing to the first image pixel in the upper left corner of the first horizontal line, during which the laser is turned off, not as an effective scanning pattern. The time period T1-T2 represents the active scanning period of the driving signal of the slow axis of the first MEMS micro-mirror 2/second MEMS micro-mirror 3 during which the slow axis of the first MEMS micro-mirror 2/second MEMS micro-mirror 3 causes the light beam to scan along the horizontal line from top to bottom under the control of the driving signal. By adjusting the amplitude a and the scanning period T2 of the driving signal of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3, the feedback signal and the scanning period of the second MEMS micro-mirror 3 are the same as those of the first MEMS micro-mirror 2, i.e. the deflection angle and the scanning period of the second MEMS micro-mirror 3 are the same as those of the first MEMS micro-mirror 2.

In this embodiment, feedback signals of the first MEMS micromirror 2 and the second MEMS micromirror 3, that is, deflection angles of the first MEMS micromirror 2 and the second MEMS micromirror 3, obtained by sensors integrated on the first MEMS micromirror 2 and the second MEMS micromirror 3, are obtained by sensors, because the sensors mostly use semiconductor materials, and changes in ambient temperature will affect characteristics of the semiconductor materials, thereby causing changes in output signals of the sensors, wherein changes in temperature mainly affect the deflection angles of the first MEMS micromirror 2 and the second MEMS micromirror 3, and therefore, the influences of the ambient temperature on the deflection angles of the first MEMS micromirror 2 and the second MEMS micromirror 3 need to be considered in real time, so as to ensure that the deflection angles of the first MEMS micromirror 2 and the second MEMS micromirror 3 are maintained unchanged.

Specifically, in step S44, the adjusting the amplitude of the driving signal of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 specifically comprises the following steps:

s441, acquiring a voltage value and a resistance value of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3;

s442, obtaining the current environment temperature according to the corresponding relation between the resistance and the temperature of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3;

s443, obtaining a target voltage value of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 at a current environment temperature and a preset deflection angle according to a corresponding relation between the temperature and the voltage of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 at the preset deflection angle;

s444, judging whether the voltage value of the first MEMS micro mirror 2/the second MEMS micro mirror 3 is equal to the target voltage value of the first MEMS micro mirror 2/the second MEMS micro mirror 3 at the current environmental temperature and the preset deflection angle, and if the voltage value of the first MEMS micro mirror/the second MEMS micro mirror is not equal to the target voltage value of the first MEMS micro mirror/the second MEMS micro mirror at the current environmental temperature and the preset deflection angle, entering the step S445;

s445, adjusting the amplitude of the driving signal of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3, so that the voltage value of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 is equal to the target voltage value of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 at the current ambient temperature and the predetermined deflection angle.

In step S441, a voltage value of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 is obtained by measuring a standard output voltage value of the piezoresistive sensor integrated on the first MEMS micro-mirror 2/the second MEMS micro-mirror 3, and a resistance value of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 is obtained by measuring a resistance value of the temperature sensor integrated on the first MEMS micro-mirror 2/the second MEMS micro-mirror 3.

In step S442, the corresponding relationship between the resistance and the temperature of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 is generated in advance, and after the resistance value of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 is obtained, the current ambient temperature of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 can be obtained according to the corresponding relationship between the resistance and the temperature of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3.

Specifically, the correspondence between the resistance and the temperature of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 is obtained by the following steps:

s4421, acquiring resistance values of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 at a plurality of ambient temperatures;

s4422, calibrating the plurality of ambient temperatures and the resistance values of the first MEMS micromirror 2/the second MEMS micromirror 3 at the plurality of ambient temperatures to obtain the corresponding relationship between the resistance and the temperature of the first MEMS micromirror 2/the second MEMS micromirror 3.

In step S4421, the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 which are not in static operation are placed at a plurality of different ambient temperatures, and resistance values of the temperature sensor on the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 at the plurality of different ambient temperatures are obtained.

In step S4422, the corresponding relationship between the resistance and the temperature of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 is obtained by linear or non-linear calibration. Of course, the above two calibration methods are only shown as examples and are not intended to limit the present application, and other calibration methods may be used to obtain the corresponding relationship between the resistance and the temperature of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3.

In step S443, the corresponding relationship between the temperature and the voltage of the first MEMS micromirror 2/the second MEMS micromirror 3 under the predetermined deflection angle is also generated in advance, and after the current ambient temperature of the first MEMS micromirror 2/the second MEMS micromirror 3 is obtained, the target voltage value of the first MEMS micromirror 2/the second MEMS micromirror 3 can be obtained according to the corresponding relationship between the temperature and the voltage of the first MEMS micromirror 2/the second MEMS micromirror 3 under the predetermined deflection angle.

Specifically, the correspondence between the temperature and the voltage of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 at a predetermined deflection angle is obtained by:

s4431, acquiring voltage values of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 at a plurality of ambient temperatures under a preset deflection angle;

s4432, calibrating the plurality of ambient temperatures and the voltage values of the first MEMS micromirror 2/the second MEMS micromirror 3 at the plurality of ambient temperatures to obtain the corresponding relationship between the voltage and the temperature of the first MEMS micromirror 2/the second MEMS micromirror 3.

In step S4431, the deflection angle of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 is maintained at a predetermined deflection angle, the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 is placed at a plurality of different ambient temperatures, and standard output voltage values of the piezoresistive sensors on the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 at the plurality of different ambient temperatures are obtained.

In step S4432, the corresponding relationship between the voltage and the temperature of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 is obtained by linear or non-linear calibration. Of course, the above two calibration methods are only shown as examples and are not intended to limit the present application, and other calibration methods may be used to obtain the voltage-temperature correspondence relationship between the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3.

In step S445, since the voltage value of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 is equal to the target voltage value of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 at the current ambient temperature and the predetermined deflection angle, it can be ensured that the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 is maintained at the predetermined deflection angle.

Referring to fig. 6, this embodiment further provides a synchronization control device of the laser radar system, where the synchronization control device includes a feedback signal obtaining module 1, a determining module 2, a working mode obtaining module 3, and an adjusting module 4.

The feedback signal acquiring module 1 is used for acquiring feedback signals of the first MEMS micromirror 2 and the second MEMS micromirror 3 in real time, the judging module 2 is used for judging whether the feedback signal of the second MEMS micromirror 3 is different from the feedback signal of the first MEMS micromirror 2, the working mode acquiring module 3 is used for acquiring working modes of the first MEMS micromirror 2 and the second MEMS micromirror 3, and the adjusting module 4 is used for adjusting driving signals of the first MEMS micromirror 2 and the second MEMS micromirror 3 according to the working modes of the first MEMS micromirror 2 and the second MEMS micromirror 3, so that the feedback signal of the second MEMS micromirror 3 is the same as the feedback signal of the first MEMS micromirror 2.

The feedback signal acquiring module 1 is specifically a sensor integrated on the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3, the sensor in this embodiment includes a piezoresistive sensor and a temperature sensor, and the feedback signal and the phase information of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 are acquired by the piezoresistive sensor integrated on the first MEMS micro-mirror 2/the second MEMS micro-mirror 3, wherein the feedback signal of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3 refers to the deflection angle of the first MEMS micro-mirror 2/the second MEMS micro-mirror 3, and the resistance value of the first MEMS micro-mirror 2/the second micro-mirror 3 is acquired by the temperature sensor integrated on the first MEMS micro-mirror 2/the second MEMS micro-mirror 3.

The laser radar system in the embodiment comprises a first MEMS micro-mirror 2, a second MEMS micro-mirror 3 and a synchronous control device, wherein the synchronous control device controls the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3 to work synchronously, so that a transmitting light path and a receiving light path of the laser radar system are mutually independent, the second MEMS micro-mirror 3 can point to receive a laser beam transmitted by the first MEMS micro-mirror 2 in real time, the distance between the first MEMS micro-mirror 2 and the second MEMS micro-mirror 3 is far less than a detection distance, the system can be equivalent to a coaxial laser radar system, compared with the existing laser radar system, a wide-angle lens and a planar array type detection device are not required to be arranged, the directive receiving of a return light pulse can be realized only by arranging one detector 4, the system structure is simplified, the light efficiency is improved, the cost is reduced, meanwhile, the influence of stray light and light leakage in the transmitting light path on the receiving light, the signal-to-noise ratio of the signal received by the detector 4 is improved.

Referring to fig. 7, the present embodiment further provides a computer storage medium 201, where the computer storage medium 201 is connected to the processor 200, a computer program is stored in the computer storage medium 201, and the processor 200 is configured to read and execute the computer program stored in the computer storage medium 201 to implement the synchronization method of the laser radar system as described above.

Example two

Referring to fig. 8, the difference between the laser radar system in the present embodiment and the first embodiment is that the laser radar system in the present embodiment includes a plurality of laser sources 1 and a plurality of detectors 4, where the number of detectors 4 is equal to the number of laser sources 1 and the plurality of detectors 4 correspond to the plurality of laser sources 1 one to one. Laser beams emitted by the laser sources 1 are incident on the first MEMS micro-mirror 2 at different incident angles, and laser beams emitted by two adjacent laser sources 1 are overlapped with each other, so that the laser beams passing through the second MEMS micro-mirror 3 are overlapped with each other and are finally received by the detectors 4 correspondingly, and the large-field-angle splicing effect is realized.

In the laser radar system in the present embodiment, the plurality of laser sources 1 and the plurality of detectors 4 are provided, and laser beams emitted from the plurality of laser sources 1 are incident at different incident angles, so that large-field-angle detection can be realized.

Implementation III

Referring to fig. 9, the difference between the laser radar system of the present embodiment and the first embodiment is that the laser radar system of the present embodiment includes a plurality of laser sources 1, a plurality of first MEMS micromirrors 2, a plurality of second MEMS micromirrors 3, and a plurality of detectors 4, wherein the laser sources 1, the first MEMS micromirrors 2, the second MEMS micromirrors 3, and the detectors 4 are equal in number and correspond to one another. Laser beams emitted by the laser sources 1 are respectively incident on the first MEMS micromirrors 2 at different incident angles, the laser beams emitted by the two adjacent laser sources 1 are overlapped with each other, and the edge junctions of the two adjacent laser beams are parallel to each other, so that the laser beams passing through the second MEMS micromirrors 3 are overlapped with each other and are finally received by the detectors 4 correspondingly, and the large-field-angle splicing effect is realized.

The laser radar system in the present embodiment can also realize large-field-angle detection by providing a plurality of laser sources 1, a plurality of first MEMS micromirrors 2, a plurality of second MEMS micromirrors 3, and a plurality of detectors 4.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the invention to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored on a computer storage medium or transmitted from one computer storage medium to another, for example, from one website, computer, server, or data center to another website, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer storage media may be any available media that can be accessed by a computer or a data storage device, such as a server, data center, etc., that incorporates one or more available media. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

Embodiments of the present invention are described with reference to flowchart illustrations and/or block diagrams of methods, apparatus, and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

The foregoing is directed to embodiments of the present application and it is noted that numerous modifications and adaptations may be made by those skilled in the art without departing from the principles of the present application and are intended to be within the scope of the present application.