A MEMS galvanometer synchronous signal feedback device, method and laser radar

Abstract

The present invention provides a MEMS galvanometer synchronization signal feedback device, method and laser radar. After the laser emitting unit emits laser and is beam shaped by the beam shaping unit, it is incident on the MEMS emitting unit driven by the MEMS driving unit and resonates and reflects to scan the plane of the object to be measured. The photodetector is used to feed back an electrical signal to the signal control and processing unit when it detects that the MEMS emitting unit is at the maximum deflection angle, so that the signal control and processing unit controls the laser driving unit according to the electrical signal to achieve synchronization between the MEMS emitting unit and the laser emitting unit. The MEMS galvanometer synchronization signal feedback device provided by the present invention introduces a feedback signal to control the light emission of the laser emitting unit to achieve synchronization and form a closed-loop control. The device as a whole is flexible and stable, and can achieve uniform or non-uniform multi-line scanning. Compared with the currently commonly used mechanical rotating laser radar device technology, it has the characteristics of small size, simple structure, and easy integration.

Description

Technical Field

[0001] The present invention relates to the technical field of laser radar, and in particular to a MEMS galvanometer synchronization signal feedback device, method and laser radar. Background Art

[0002] LiDAR detects target position, speed and other information by emitting laser beams. It has the advantages of high ranging accuracy, strong directionality, fast response, and no influence from ground clutter, and has been widely used in various fields of society. LiDAR can form three-dimensional environmental map data with an accuracy of up to centimeters, so it has important applications in advanced driver assistance systems (ADAS) and unmanned driving systems.

[0003] At present, the technical solutions applied to scanning laser radar systems are mainly based on mechanical rotating parts. The motor structure is complex, the size is large, and it is not easy to integrate. In addition, there is a technical solution that uses the resonance of the MEMS galvanometer to change the optical path to complete multi-beam scanning. This solution improves the stability of the overall system and has the characteristics of small size, simple structure, and low cost. However, since it is difficult to synchronize the real-time position information of the MEMS galvanometer during the vibration process and the control signal of the laser emission unit, it brings great difficulties to the system design and debugging. Summary of the invention

[0004] In view of the defects in the prior art, the present invention provides a MEMS galvanometer synchronization signal feedback device, method and laser radar. The present invention can achieve synchronous control of laser emission and MEMS galvanometer oscillation, and has a simple structure, is easy to implement, has low cost and good stability.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] In a first aspect, the present invention provides a MEMS galvanometer synchronous signal feedback device, comprising: a laser driving unit, a laser emitting unit, a beam shaping unit, a MEMS driving unit, a MEMS emitting unit, a photodetector, and a signal control and processing unit, wherein the signal control and processing unit is connected to the laser driving unit and the photodetector respectively;

[0007] The laser emitting unit emits laser light under the drive of the laser driving unit, and after the laser light is shaped by the beam shaping unit, the laser light is incident on the MEMS emitting unit driven by the MEMS driving unit, and the MEMS emitting unit performs a field of view scan on the plane of the object to be measured after resonant reflection; wherein the MEMS driving unit drives the MEMS emitting unit to oscillate at a preset resonant frequency to ensure that the actual scanning field of view range w1 of the laser light after the resonant reflection by the MEMS emitting unit is greater than the field of view range w2 of the plane of the object to be measured;

[0008] The photoelectric detector is located within the actual scanning field of view and outside the field of view of the plane of the object to be measured, and the photoelectric detector is used to detect whether the MEMS transmitting unit is at a maximum deflection angle, and send an electrical signal to the signal control and processing unit when detecting that the MEMS transmitting unit is at a maximum deflection angle;

[0009] The signal control and processing unit controls the laser driving unit upon receiving the electrical signal, thereby achieving synchronization between the MEMS emitting unit and the laser emitting unit.

[0010] Furthermore, there is one photodetector, which is used to detect the positive maximum deflection angle or the negative maximum deflection angle of the MEMS transmitting unit, wherein the photodetector is placed at a position where it can only receive the light beam reflected by the positive maximum deflection angle or the negative maximum deflection angle but not the light beam reflected by other deflection angles.

[0011] Furthermore, there are two photodetectors, wherein the first photodetector is used to detect the positive maximum deflection angle of the MEMS emitting unit, and the second photodetector is used to detect the negative maximum deflection angle of the MEMS emitting unit; wherein the first photodetector is placed at a position where it can only receive the light beam reflected by the positive maximum deflection angle but not the light beam reflected by other deflection angles; and the second photodetector is placed at a position where it can only receive the light beam reflected by the reverse maximum deflection angle but not the light beam reflected by other deflection angles.

[0012] Furthermore, the device further comprises: a light beam receiving unit, which is used to converge the laser echo signal reflected from the plane of the object to be measured onto the photodetector.

[0013] Furthermore, the light beam receiving unit is composed of more than two lenses or field lenses.

[0014] Furthermore, the lens or field lens is made of a material with high transmittance to near-infrared.

[0015] Furthermore, the driving mode of the MEMS driving unit includes one or more of piezoelectric driving, electrothermal driving, electrostatic driving and electromagnetic driving.

[0016] Furthermore, the beam shaping unit is composed of more than two aspherical or free-form lenses or more than two ordinary lenses, and is used to shape the laser beam emitted by the laser emitting unit.

[0017] In a second aspect, the present invention further provides a MEMS galvanometer synchronization signal feedback method based on the above-mentioned MEMS galvanometer synchronization signal feedback device, comprising:

[0018] S1, the MEMS transmitting unit oscillates according to a preset resonant frequency under the drive of the MEMS driving unit, wherein the actual scanning field of view of the laser after the resonant reflection of the MEMS transmitting unit is larger than the field of view of the plane of the object to be measured;

[0019] S2, the laser emitting unit emits a laser beam under the drive of the laser driving unit;

[0020] S3, the photoelectric detector is used to detect whether the MEMS transmitting unit is at the maximum deflection angle, and when it is detected that the MEMS transmitting unit is at the maximum deflection angle, feed back an electrical signal to the signal control and processing unit;

[0021] S4, the signal control and processing unit controls the laser driving unit according to the electrical signal to achieve synchronization between the MEMS emitting unit and the laser emitting unit;

[0022] S5, looping through steps S2 to S4 to achieve real-time field of view line beam angle uniformity or sparse and dense multi-line scanning.

[0023] In a third aspect, the present invention further provides a laser radar, comprising the MEMS galvanometer synchronization signal feedback device as described above.

[0024] It can be seen from the above technical solution that the MEMS galvanometer synchronous signal feedback device provided by the present invention uses a photoelectric detector to obtain the real-time position information (maximum deflection angle) of the MEMS emitting unit during the vibration process, and feeds back the position information of the MEMS emitting unit to the laser driving unit, so that the laser driving unit drives the laser emitting unit according to the position information of the MEMS emitting unit, thereby realizing the synchronous control of the light emission of the laser emitting unit and the oscillation of the MEMS emitting unit. Furthermore, the MEMS galvanometer synchronous signal feedback device provided by the present invention has the advantages of small size, simple structure, easy implementation, low cost, good stability, and easy integration compared to the currently commonly used mechanical rotating laser radar device. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 It is a structural schematic diagram of a MEMS galvanometer synchronization signal feedback device provided by an embodiment of the present invention;

[0027] Figure 2 It is a schematic diagram of the working principle of a MEMS galvanometer synchronization signal feedback device provided by an embodiment of the present invention;

[0028] Figure 3 It is a schematic diagram of the relationship between the laser driving signal, the MEMS galvanometer driving signal and the MEMS oscillation signal provided by an embodiment of the present invention;

[0029] Figure 4 is a flow chart of a MEMS galvanometer synchronization signal feedback method provided by another embodiment of the present invention;

[0030] The meanings of the numbers in the above figures are as follows:

[0031] 101 represents a laser driving unit; 102 represents a laser emitting unit; 103 represents a beam shaping unit; 104 represents a MEMS driving unit; 105 represents a MEMS emitting unit; 106 represents a scanning area object plane; 107 represents a first photodetector; 108 represents a second photodetector; 109 represents a signal control and processing unit; 201 represents a main optical axis light position; 1061 represents a plane of an object to be measured; 1062 represents a first reference object plane; 1063 represents a second reference object plane. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The technical difficulty in existing laser radars that use MEMS galvanometers to achieve multi-beam scanning is that it is difficult to synchronize laser emission with MEMS galvanometer vibration. To solve this problem, an embodiment of the present invention provides a MEMS galvanometer synchronization signal feedback device, see Figure 1 and Figure 2The feedback device includes: a laser driving unit 101, a laser emitting unit 102, a beam shaping unit 103, a MEMS driving unit 104, a MEMS emitting unit 105, photodetectors 107 and 108, and a signal control and processing unit 109, wherein the signal control and processing unit 109 is connected to the laser driving unit 101 and the photodetectors 107 and 108 respectively; it can be understood that the MEMS emitting unit 105 is implemented by a MEMS galvanometer; the beam shaping unit 103 is composed of more than two aspherical or free-form lenses or more than two ordinary lenses, and is used to shape the laser beam emitted by the laser emitting unit 102; the main optical axes of the laser emitting unit 102 and the mirror groups of the MEMS emitting unit 105 and the beam shaping unit 103 are kept coincident;

[0034] The laser emitting unit 102 emits laser under the drive of the laser driving unit 101, and after the laser is shaped by the beam shaping unit 103, it is incident on the MEMS emitting unit 105 driven by the MEMS driving unit 104, and the MEMS emitting unit 105 performs resonant reflection and then scans the field of view of the plane of the object to be measured; wherein, the MEMS driving unit 104 drives the MEMS emitting unit 105 to oscillate according to a preset resonant frequency to ensure that the actual scanning field of view range w1 of the laser after resonant reflection by the MEMS emitting unit 105 is greater than the field of view range w2 of the plane of the object to be measured; it can be understood that the MEMS driving unit 104 can change the resonant frequency of the MEMS emitting unit 105 by adjusting the frequency of the driving circuit, thereby changing the actual scanning field of view range of the MEMS emitting unit 105; it can be understood that the driving mode of the MEMS driving unit 104 can include one or more of piezoelectric driving, electrothermal driving, electrostatic driving and electromagnetic driving.

[0035] The photodetector is located within the actual scanning field of view and outside the field of view of the plane of the object to be measured. For example, the photodetector is located at a position where the laser beam reflected by the MEMS emitting unit 105 at the maximum deflection angle can pass through the photodetector and the laser beam reflected at other deflection angles cannot pass through the photodetector, so that the photodetector can detect whether the MEMS emitting unit 105 is at the maximum deflection angle according to whether the optical signal is received, and send an electrical signal to the signal control and processing unit 109 when detecting that the MEMS emitting unit 105 is at the maximum deflection angle;

[0036] The signal control and processing unit 109 controls the laser driving unit 101 upon receiving the electrical signal, thereby achieving synchronization between the MEMS emitting unit 105 and the laser emitting unit 102 .

[0037] It can be seen that the MEMS galvanometer synchronization signal feedback device provided by the embodiment of the present invention realizes closed-loop synchronization control.

[0038] It can be understood that since the laser emitted by the laser emitting unit 102 is a periodic pulse signal, and when the MEMS emitting unit 105 is in a resonant state, its deflection angle is in a sinusoidal function relationship with time. In one resonant cycle, the MEMS emitting unit has a positive maximum deflection angle and a negative maximum deflection angle. Therefore, the laser emitting unit can be controlled to emit light synchronously according to the detected positive maximum deflection angle or negative maximum deflection angle of the MEMS emitting unit, thereby achieving synchronization between the laser emitting unit and the MEMS emitting unit. Figure 3 Schematic diagram of the relationship between the laser drive signal, the MEMS galvanometer drive signal and the MEMS oscillation signal provided by the embodiment of the present invention. Figure 3 It can be seen that when the MEMS galvanometer is in a resonant state, its deflection angle is in a sinusoidal function relationship with time. During a periodic change, the MEMS drive voltage signal is triggered by a square wave signal, and its rising edge corresponds to the maximum deflection angle of the MEMS galvanometer, and the laser drive signal is a periodic pulse signal.

[0039] It can be understood that the number of the photodetector can be one. When the number of the photodetector can be one, the photodetector is used to detect the positive maximum deflection angle or the negative maximum deflection angle of the MEMS transmitting unit; wherein the photodetector is placed at a position where it can only receive the light beam reflected by the positive maximum deflection angle or the negative maximum deflection angle but not receive the light beam reflected by other deflection angles.

[0040] It can be understood that the number of the photodetectors can also be two. When the number of the photodetectors can be two, the first photodetector is used to detect the positive maximum deflection angle of the MEMS emitting unit, and the second photodetector is used to detect the negative maximum deflection angle of the MEMS emitting unit; wherein the first photodetector is placed at a position where it can only receive the light beam reflected by the positive maximum deflection angle but not the light beam reflected by other deflection angles; and the second photodetector is placed at a position where it can only receive the light beam reflected by the reverse maximum deflection angle but not the light beam reflected by other deflection angles.

[0041] See also Figure 1 and Figure 2 In this embodiment, the object plane located within the actual scanning field of view and outside the field of view of the object plane to be measured is defined as the reference object plane (1062 and 1063). The object plane to be measured (1061) and the reference object plane (1062 and 1063) together constitute Figure 1 The reference object plane includes Figure 2 The first reference object plane 1062 and the second reference object plane 1063 are shown in the figure. This embodiment also defines that the light signal scanned onto the reference object plane is called the reference light signal, and the reference light signal includes the first reference light signal scanned onto the first reference object plane 1062 and the second reference light signal scanned onto the second reference object plane 1063. Figure 2 The first photodetector 107 and the second photodetector 108 shown in the figure are used to detect edge light signals within the field of view of the first reference light signal and edge light signals within the field of view of the second reference light signal, respectively. When the first photodetector 107 detects edge light signals within the field of view of the first reference light signal, it indicates that the MEMS emitting unit 105 is at the maximum positive deflection angle at this time, and when the second photodetector 108 detects edge light signals within the field of view of the second reference light signal, it indicates that the MEMS emitting unit 105 is at the maximum negative deflection angle at this time. It can be seen that the embodiment of the present invention utilizes the photoelectric effect of the photodetector to convert the optical signal into an electrical signal, and transmits the electrical signal to the signal control and processing unit 109, and then the signal control and processing unit 109 controls the laser driving unit 101 to achieve synchronization between the MEMS emitting unit 105 and the laser emitting unit 102.

[0042] It can be understood that if the actual scanning field of view of the MEMS transmitting unit 105 at the maximum deflection angle corresponds to w1 = 35°, and the field of view of the plane of the object to be measured corresponds to w2 = 30°, then the first photodetector is placed at a position where it can only receive θ = +17.5 ° The second photodetector is placed at a position that can only receive θ = -17.5 ° the actual location.

[0043] It is understandable that when adopting Figure 2 When the two photodetectors shown perform signal feedback, it means that the MEMS galvanometer synchronization signal feedback device performs two synchronization calibrations within one resonance period, thereby being able to more accurately achieve synchronization between the MEMS emitting unit and the laser emitting unit.

[0044] In addition, in order to reduce equipment cost and complexity, the number of the photodetector can also be one. One photodetector can be used to detect the positive maximum deflection angle or the negative maximum deflection angle of the MEMS transmitting unit. When the number of the photodetector is one, it is equivalent to performing a synchronous calibration once in one resonance cycle.

[0045] In addition, it should be noted that the number and specific location of the photodetectors are not limited in this embodiment, as long as the photodetectors can detect whether the MEMS transmitting unit is at the maximum deflection angle and cannot detect other deflection angles of the MEMS transmitting unit.

[0046] Depend on Figure 1 and Figure 2 It can be seen from the content shown that the MEMS galvanometer synchronous signal feedback device provided by the embodiment of the present invention uses the resonant vibration of the MEMS micro-galvanometer to reflect the light beam emitted to the mirror surface of the MEMS micro-galvanometer to the target object within a certain field of view and distance range, and at the same time introduces a reference light signal into the edge field of view outside the plane of the object to be measured to form signal feedback control. Compared with the device that realizes laser scanning by mechanical scanning or motor drive, the MEMS galvanometer improves the stability, angular resolution and scanning frequency of the scanning laser radar, and is easy to integrate, which is conducive to promoting the development of laser radar technology towards miniaturization, lightweight and integration.

[0047] In an optional embodiment, the MEMS galvanometer synchronization signal feedback device further includes: a beam receiving unit, the beam receiving unit is used to converge the laser echo signal reflected from the plane of the object to be measured onto the photodetector. Preferably, the beam receiving unit is composed of more than two lenses or field mirrors, and the lenses or field mirrors are made of materials with high transmittance to near-infrared.

[0048] Furthermore, since the laser emitting unit can emit a laser beam of any frequency, if the frequency and delay of the laser beam are controlled according to the electrical signal fed back by the photodetector, uniform angle scanning or sparse and uneven density scanning can be achieved under multiple beams. For example, the light emission frequency can be increased at important parts of the detection, the amount of data can be increased, and the true state of the object being measured can be more accurately identified; the overall scanning of the system can be more reasonable, and the application prospects can be broader.

[0049] As can be seen from the above description, the MEMS galvanometer synchronous signal feedback device provided in the embodiment of the present invention uses a photoelectric detector to obtain the real-time position information (maximum deflection angle) of the MEMS emitting unit during the vibration process, and feeds back the position information of the MEMS emitting unit to the laser driving unit, so that the laser driving unit drives the laser emitting unit according to the position information of the MEMS emitting unit, thereby realizing the synchronous control of the light emission of the laser emitting unit and the oscillation of the MEMS emitting unit. Furthermore, the MEMS galvanometer synchronous signal feedback device provided in the embodiment of the present invention has the advantages of small size, simple structure, easy implementation, low cost, good stability, and easy integration compared to the currently commonly used mechanical rotating laser radar device.

[0050] Based on the same inventive concept, another embodiment of the present invention provides a MEMS galvanometer synchronization signal feedback method based on the MEMS galvanometer synchronization signal feedback device described in the above embodiment, see Figure 4 , the method comprises the following steps:

[0051] S1: The MEMS transmitting unit oscillates at a preset resonant frequency under the drive of the MEMS driving unit, wherein an actual scanning field of view of the laser after resonant reflection by the MEMS transmitting unit is larger than a field of view of a plane of the object to be measured.

[0052] S2: The laser emitting unit emits a laser beam under the drive of the laser driving unit.

[0053] S3: The photodetector is used to detect whether the MEMS transmitting unit is at a maximum deflection angle, and when it is detected that the MEMS transmitting unit is at a maximum deflection angle, feed back an electrical signal to the signal control and processing unit.

[0054] S4: The signal control and processing unit controls the laser driving unit according to the electrical signal to achieve synchronization between the MEMS emitting unit and the laser emitting unit.

[0055] S5: looping through steps S2 to S4 to achieve real-time field of view line beam angle uniformity or sparse and dense multi-line scanning.

[0056] The MEMS galvanometer synchronization signal feedback method provided in this embodiment is implemented by using the MEMS galvanometer synchronization signal feedback device described in the above embodiments, so its principle and technical effect are similar and will not be described in detail here.

[0057] Based on the same inventive concept, another embodiment of the present invention provides a laser radar, which includes the MEMS galvanometer synchronization signal feedback device described in the above embodiment.

[0058] The laser radar provided in this embodiment includes the MEMS galvanometer synchronization signal feedback device described in the above embodiments, so its principles and technical effects are similar and will not be repeated here.

[0059] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A MEMS galvanometer synchronous signal feedback device, characterized in that: include: A laser driving unit, a laser emitting unit, a beam shaping unit, a MEMS driving unit, a MEMS emitting unit, a photodetector, and a signal control and processing unit, wherein the signal control and processing unit is connected to the laser driving unit and the photodetector respectively; The laser emitting unit emits laser light under the drive of the laser driving unit, and after the laser light is shaped by the beam shaping unit, the laser light is incident on the MEMS emitting unit driven by the MEMS driving unit, and the MEMS emitting unit performs a resonant reflection to scan the field of view of the plane of the object to be measured; wherein the MEMS driving unit drives the MEMS emitting unit to oscillate according to a preset resonant frequency to ensure that the actual scanning field of view range w1 of the laser light after the resonant reflection of the MEMS emitting unit is greater than the field of view range w2 of the plane of the object to be measured; when the MEMS emitting unit is in a resonant state, its deflection angle is in a sinusoidal function relationship with time; The photoelectric detector is located within the actual scanning field of view and outside the field of view of the plane of the object to be measured, and the photoelectric detector is used to detect whether the MEMS transmitting unit is at a maximum deflection angle, and send an electrical signal to the signal control and processing unit when detecting that the MEMS transmitting unit is at a maximum deflection angle; When receiving the electrical signal, the signal control and processing unit controls the laser driving unit to drive the laser emitting unit to emit light synchronously, thereby achieving synchronization between the MEMS emitting unit and the laser emitting unit.

2. The device according to claim 1, characterized in that The number of the photodetector is one, and the photodetector is used to detect the positive maximum deflection angle or the negative maximum deflection angle of the MEMS transmitting unit; wherein the photodetector is placed at a position where it can only receive the light beam reflected by the positive maximum deflection angle or the negative maximum deflection angle but not receive the light beam reflected by other deflection angles.

3. The device according to claim 1, characterized in that There are two photodetectors, the first photodetector is used to detect the positive maximum deflection angle of the MEMS emitting unit, and the second photodetector is used to detect the negative maximum deflection angle of the MEMS emitting unit; wherein the first photodetector is placed at a position where it can only receive the light beam reflected by the positive maximum deflection angle but not the light beam reflected by other deflection angles; and the second photodetector is placed at a position where it can only receive the light beam reflected by the reverse maximum deflection angle but not the light beam reflected by other deflection angles.

4. The device according to claim 1, characterized in that Also includes: A light beam receiving unit is used to converge the laser echo signal reflected from the plane of the object to be measured onto the photodetector.

5. The device according to claim 4, characterized in that The light beam receiving unit is composed of more than two lenses or field lenses.

6. The device according to claim 5, characterized in that The lens or field mirror is made of a material with high transmittance to near infrared.

7. The device according to claim 1, characterized in that The driving mode of the MEMS driving unit includes one or more of piezoelectric driving, electrothermal driving, electrostatic driving and electromagnetic driving.

8. The device according to claim 1, characterized in that The beam shaping unit is composed of more than two aspherical or free-form lenses or more than two ordinary lenses, and is used to shape the laser beam emitted by the laser emitting unit.

9. A method for feedback of a MEMS galvanometer synchronization signal based on the MEMS galvanometer synchronization signal feedback device according to any one of claims 1 to 8, characterized in that: include: S1, the MEMS transmitting unit oscillates at a preset resonant frequency under the drive of the MEMS driving unit, wherein the actual scanning field of view of the laser after the resonant reflection of the MEMS transmitting unit is larger than the field of view of the plane of the object to be measured; when the MEMS transmitting unit is in a resonant state, its deflection angle is in a sinusoidal function relationship with time; S2, the laser emitting unit emits a laser beam under the drive of the laser driving unit; S3, the photoelectric detector is used to detect whether the MEMS transmitting unit is at the maximum deflection angle, and when it is detected that the MEMS transmitting unit is at the maximum deflection angle, feed back an electrical signal to the signal control and processing unit; S4, the signal control and processing unit controls the laser driving unit according to the electrical signal to drive the laser emitting unit to emit light synchronously, thereby achieving synchronization between the MEMS emitting unit and the laser emitting unit; S5, looping through steps S2 to S4 to achieve real-time field of view line beam angle uniformity or sparse and dense multi-line scanning.

10. A laser radar, characterized in that: It comprises the MEMS galvanometer synchronization signal feedback device as described in any one of claims 1 to 8.

Images