Laser ranging system

Abstract

The present application is about a laser ranging system, which belongs to the field of laser ranging technology. The laser ranging system includes a laser emitting unit, a laser receiving unit, a scanning mirror and an optical feedback component; the scanning mirror is located on the emitting optical path of the laser emitting unit and the receiving optical path of the laser receiving unit; when the scanning mirror rotates within a first angle range, the optical feedback component is located on the optical path of the scanning mirror, and when the scanning mirror rotates within a second angle range, the target to be measured is located on the optical path of the scanning mirror. By adopting the present application, the measurement accuracy of the laser ranging system can be improved.

Description

Technical Field

[0001] The present application relates to the field of laser ranging technology, and in particular to a laser ranging system. Background Art

[0002] The laser ranging system is a system that emits a laser beam to detect targets. Its working principle is that the transmitter emits a laser beam to the target. After the laser beam encounters the target, it is reflected to the receiving end. The processing chip in the laser ranging system can calculate the distance to the target based on the time when the transmitter emits the laser beam, the time when the receiving end receives the laser beam, and the propagation speed of the laser (i.e. the speed of light).

[0003] The time when the receiving end receives the laser beam is usually the time when the processing chip receives the signal. When the receiving end receives an optical signal, it converts the optical signal into an electrical signal, processes the electrical signal, and sends it to the processing chip. The processing chip records the time when the electrical signal is received as the time when the receiving end receives the optical signal. It can be seen that the accuracy of the distance value measured by the laser ranging system is low. Summary of the invention

[0004] The present application provides a laser distance measurement system, which can overcome the problem of low accuracy of the distance value measured by the laser distance measurement system in the related art. The technical solution is as follows:

[0005] According to the present application, a laser ranging system is provided, the laser ranging system comprising a laser emitting unit, a laser receiving unit, a scanning mirror and an optical feedback component;

[0006] The scanning mirror is located on the emitting optical path of the laser emitting unit and the receiving optical path of the laser receiving unit;

[0007] When the scanning mirror rotates within a first angle range, the optical feedback component is located on the optical path of the scanning mirror, and when the scanning mirror rotates within a second angle range, the target to be measured is located on the optical path of the scanning mirror.

[0008] In a possible implementation, the optical feedback assembly includes a first reflector and a second reflector;

[0009] The laser emitting part, the first part of the scanning mirror and the first reflector are located on the same side, and the first part is located on the emitting light path of the laser emitting part, and the first reflector is located on the reflecting light path of the first part;

[0010] The laser receiving part, the second part of the scanning mirror and the second reflector are located on the same side, and the second part is located on the incident light path of the laser receiving part, the second reflector is located on the incident light path of the second part, and the second reflector is located on the reflected light path of the first reflector.

[0011] In a possible implementation, the laser ranging system further includes a light blocking plate, the laser emitting unit, the first part of the scanning mirror, and the first reflector are located on one side of the light blocking plate, and the laser receiving unit, the second part of the scanning mirror, and the second reflector are located on the other side of the light blocking plate;

[0012] The light blocking plate has a light through hole at a position corresponding to the reflection light path of the first reflector.

[0013] In a possible implementation manner, the light blocking plate includes a rotating portion and a fixed portion, the scanning mirror passes through the rotating portion, and the rotating portion can rotate synchronously with the scanning mirror.

[0014] In a possible implementation manner, the reflective surface of the first reflective element and the reflective surface of the second reflective element are mirror-symmetrical.

[0015] In a possible implementation manner, the reflective surface of the first reflective element is made of a mirror material.

[0016] In a possible implementation manner, the reflective surface of the second reflective element is made of a diffuse reflective material.

[0017] In a possible implementation, the area of ​​the reflective surface of the first reflector satisfies that the rotation angle range of the scanning mirror is less than or equal to 5 degrees, and the first reflector can receive the laser reflected by the scanning mirror.

[0018] In a possible implementation manner, the area of ​​the reflective surface of the second reflective element is not less than the receiving aperture of the laser receiving part.

[0019] In a possible implementation manner, when the scanning mirror rotates within a first angle range, the optical feedback component is located on an optical path of a first reflective surface of the scanning mirror;

[0020] When the scanning mirror rotates within the second angle range, the target to be measured is located in the optical path of the second reflection surface of the scanning mirror, and the first reflection surface and the second reflection surface are opposite to each other.

[0021] In the embodiment of the present application, the laser ranging system includes not only a laser emitting unit, a laser receiving unit and a scanning mirror, but also an optical feedback component. When the scanning mirror rotates within a first angle range, the laser emitted by the laser emitting unit enters the laser receiving unit via the optical feedback component. When the scanning mirror rotates within a second angle range, the laser emitted by the laser emitting unit enters the laser receiving unit via the target to be measured. Whether the laser enters the laser receiving unit via the optical feedback component or via the target, the process from the processing chip to the laser emitting unit is exactly the same, and the processing process after entering the laser receiving unit is also exactly the same. Therefore, the error generated from the processing chip to the laser emitting unit and the error generated after the laser enters the laser receiving unit can be eliminated by subtracting the data within the first angle range and the data within the second angle range, thereby improving the measurement accuracy of the laser ranging system.

[0022] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings herein are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application. In the drawings:

[0024] Figure 1 is a schematic structural diagram of a laser ranging system according to an embodiment;

[0025] Figure 2 is a schematic diagram of the distance measurement principle of a laser distance measurement system according to an embodiment;

[0026] Figure 3 is a schematic diagram of a time axis of a laser ranging system at various time points in ranging according to an embodiment;

[0027] Figure 4 is a schematic top view of a laser ranging system according to an embodiment.

[0028] Legend

[0029] 1. Laser emitting unit;

[0030] 2. Laser receiving unit;

[0031] 3. Scanning mirror; 31. First part; 32. Second part;

[0032] 4. Optical feedback component; 41. First reflective member; 42. Second reflective member;

[0033] 5. Light blocking plate; 51. Light through hole; 52. Rotating part; 53. Fixed part.

[0034] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0035] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0036] The terms used in the embodiments of the present disclosure are only used to explain the embodiments of the present disclosure, and are not intended to limit the present disclosure. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second", "third" and similar words used in the patent application specification and claims of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. "Including" or "including" and similar words mean that the elements or objects appearing in front of "including" or "including" include the elements or objects listed after "including" or "including" and their equivalents, and do not exclude other elements or objects. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0037] The present application embodiment provides a laser ranging system, which can be applied to laser radar. Figure 1 As shown, the laser ranging system includes a laser emitting unit 1 and a laser receiving unit 2. The laser emitting unit 1 may include, for example, a laser for emitting laser light to a target to be measured. The laser receiving unit 2 may include, for example, a detector array for receiving laser light reflected from a target to be measured, wherein each detector in the detector array included in the laser receiving unit 2 corresponds to a light channel, and the laser light enters the detector from the light channel and is received by the detector.

[0038] In order to calculate the distance between the laser ranging system and the target to be measured according to the time of emitting the laser and the time of receiving the laser, the laser ranging system also includes a processing chip ( Figure 1 The processing chip is electrically connected to the laser emitting unit 1 and the laser receiving unit 2, respectively, so as to control the laser emitting unit 1 to emit laser light and receive laser light from the laser receiving unit 2, record the emission time and the receiving time, and calculate the distance between the laser ranging system and the target to be measured according to the emission time, the receiving time and the speed of light.

[0039] In one example, in order to measure the distance between the laser ranging system and the target at multiple positions, accordingly, Figure 1 As shown, the laser ranging system further includes a scanning mirror 3. The scanning mirror 3 is a rotatable reflector, and its rotation can be driven by a driving member. Figure 1 The drive member is not shown.

[0040] It should be pointed out that the laser ranging system also includes a housing, in which the laser emitting unit 1, the laser receiving unit 2, the processing chip and the scanning mirror 3, as well as the optical feedback component 4 and the light baffle 5 to be introduced below are all fixed.

[0041] like Figure 1 As shown, the scanning mirror 3 is located on the emission light path of the laser emitting unit 1, so that the laser emitted by the laser emitting unit 1 can be incident on the scanning mirror 3 and can be reflected to the target through the scanning mirror 3. Since the scanning mirror 3 can rotate, the incident angle incident on the scanning mirror 3 changes with the rotation of the scanning mirror 3, so the position where the laser reflected to the target through the scanning mirror 3 hits the target also changes, so that the distance between the laser ranging system and multiple positions of the target can be measured.

[0042] In one example, the size of the scanning mirror 3 is relatively large, a part of which is located on the emission light path of the laser emitting unit 1, and the other part is located on the incident light path of the laser receiving unit 2. Figure 1 As shown, the first part 31 of the scanning mirror 3 is located on the emission light path of the laser emitting unit 1, and the second part 32 of the scanning mirror 3 is located on the incident light path of the laser receiving unit 2. In this way, after the laser emitted by the laser emitting unit 1 falls on the first part 31 of the scanning mirror 3, the laser reflected by the first part 31 of the scanning mirror 3 can fall on the target, and the laser diffusely reflected by the target falls on the second part 32 of the scanning mirror 3, and enters the laser receiving unit 2 after being reflected by the second part 32 of the scanning mirror 3.

[0043] In one example, the principle of a laser ranging system for measuring the distance to a target can be seen in Figure 2 As shown, the processing chip sends a driving electrical signal to the laser emitting unit 1 and starts timing at the same time. The current time can be recorded as t1. After receiving the driving electrical signal, the laser emitting unit 1 emits the laser. After the laser encounters the target to be measured, it is reflected. The laser reflected back by the target enters the laser receiving unit 2. After receiving the laser, the laser receiving unit 2 converts the optical signal into an electrical signal and performs some processing, such as noise reduction, amplification and shaping. The processed electrical signal is sent to the processing chip. When the processing chip receives the processed electrical signal, it stops timing and records the current time as t2. In this way, the processing chip can calculate the current time according to the formula Where Δt is t2-t1, c is the speed of light, and d is the distance between the laser ranging system and the target.

[0044] According to the above, if Figure 3 In the time axis shown, t1 is the moment when the processing chip sends the driving electrical signal to the laser emitting unit 1, not t3, the moment when the laser emitting unit 1 emits the laser. It can be seen that the start time is earlier than the actual time. Similarly, t2 is the moment when the processing chip receives the processed electrical signal, not t4, the moment when the laser receiving unit 2 receives the optical signal. In addition, after the laser receiving unit 2 receives the optical signal, it needs to undergo photoelectric conversion, as well as noise reduction, amplification, and shaping of the electrical signal. The processing process is relatively complicated and takes a long time, resulting in a large time difference between t4 and t2. It can be seen that through Figure 2 The distance values ​​calculated based on t2 and t1 shown will result in a lower accuracy of the calculated distance values.

[0045] Moreover, components such as the laser receiving unit 2 and the processing chip may also experience temperature drift due to temperature changes, resulting in random errors.

[0046] It can be seen that whether it is time delay or random errors generated by the device during operation, it will cause the accuracy of the distance measured by the laser ranging system to be low.

[0047] In order to improve the accuracy of the laser ranging system, the corresponding Figure 1 As shown, the laser ranging system also includes an optical feedback component 4. The optical feedback component 4 is used to eliminate the time error, which includes the difference between the time when the laser emitting unit 1 emits the laser and the time when the processing chip sends the driving electrical signal (i.e. Δt1, i.e. t3-t1), and the difference between the time when the processing chip receives the processed electrical signal and the time when the laser receiving unit 2 receives the laser (i.e. Δt2, i.e. t2-t4). Once the time error is eliminated, the ranging accuracy of the laser ranging system can be improved.

[0048] Since the scanning mirror 3 can rotate, when the scanning mirror 3 rotates within the first angle range α, the optical feedback component 4 is located on the optical path of the scanning mirror 3 ; when the scanning mirror 3 rotates within the second angle range β, the target to be measured is located on the optical path of the scanning mirror 3 .

[0049] The sum of the first angle range and the second angle range is less than 360 degrees.

[0050] In one example, if Figure 4As shown, the first angle range α may correspond to the first reflection surface of the scanning mirror 3, such as the back side of the scanning mirror 3, and the second angle range β may correspond to the second reflection surface of the scanning mirror 3, and the second reflection surface and the first reflection surface are located opposite to each other, such as the front side of the scanning mirror 3. In this way, when the scanning mirror 3 rotates within the first angle range α, the optical feedback component 4 is located on the optical path of the first reflection surface of the scanning mirror 3. When the scanning mirror 3 rotates within the second angle range β, the target to be measured is located on the optical path of the second reflection surface of the scanning mirror. Among them, Figure 4 It is a schematic diagram of the laser ranging system in a bird's-eye view.

[0051] In another example, the first angle range and the second angle range may both correspond to the same reflective surface of the scanning mirror 3 , but the positions of the scanning mirror 3 are different.

[0052] It can be seen that Figure 4 As shown, the scanning mirror 3 includes two scanning fields of view, namely, the scanning field of view corresponding to the first angle range α and the scanning field of view corresponding to the second angle range β. In the scanning field of view corresponding to the first angle range α, the laser will pass through the optical feedback component 4 and enter the laser receiving part 2, which can be recorded as the back field of view. In the scanning field of view corresponding to the second angle range β, the laser will pass through the target to be measured and enter the laser receiving part 2, which can be recorded as the front field of view.

[0053] In the back field of view, the optical feedback component 4 is located on the optical path of the scanning mirror 3 , for example, the optical feedback component 4 is located on the reflection optical path of the first part 31 of the scanning mirror 3 , and the optical feedback component 4 is also located on the incident optical path of the second part 32 of the scanning mirror 3 .

[0054] In this way, when the scanning mirror 3 rotates within the first angle range, the processing chip drives the laser emitted by the laser emitting unit 1 to be incident on the scanning mirror 3. Since the optical feedback component 4 is located on the optical path of the scanning mirror 3, the laser reflected by the first part 31 of the scanning mirror 3 will be incident on the optical feedback component 4. The laser reflected by the optical feedback component 4 will fall on the second part 32 of the scanning mirror 3 and then be incident on the laser receiving unit 2. This process is the optical transmission process, referred to as the optical process. The process from the processing chip to the laser emitting unit 1 can be called the transmitting electrical process, and the process from the laser receiving unit 2 to the processing chip, including the photoelectric signal conversion process, electrical signal transmission and electrical signal processing, can be called the receiving electrical process.

[0055] When the scanning mirror 3 rotates within the second angle range, the processing chip drives the laser emitted by the laser emitting unit 1 to be incident on the scanning mirror 3. Since the target is located on the optical path of the scanning mirror 3, the laser reflected by the first part 31 of the scanning mirror 3 will be incident on the target, and the laser reflected by the target will fall on the second part of the scanning mirror 3, and then be incident on the laser receiving unit 2. This process is the light transmission process, referred to as the light process. The process from the processing chip to the laser emitting unit 1 can be called the transmitting electrical process, and the process from the laser receiving unit 2 to the processing chip, including the photoelectric signal conversion process, electrical signal transmission and electrical signal processing, can be called the receiving electrical process.

[0056] As can be seen from the above, the optical process of the scanning mirror 3 rotating within the first angle range and the second angle range is different, but the transmitting electrical process is the same and the receiving electrical process is also the same. That is, in the two angle ranges, although the actual optical path of the laser is different, the process of the processing chip driving the laser emitting unit to emit the laser and the processing process of the laser after entering the laser receiving unit 2 are exactly the same. Moreover, the rotation of the scanning mirror 3 within these two angle ranges belongs to the same frame. For example, within the same scanning cycle of the scanning mirror 3, taking 20Hz as an example, the time interval of the data within the two angle ranges does not exceed 50ms, and the time interval is very small. Then, the errors of the data within the two angle ranges in the electrical process from the processing chip to the laser emitting unit 1 and the electrical process from the laser receiving unit 2 to the processing chip are the same, and this part of the time error can be completely eliminated by subtracting each other. After eliminating the time error, it is only necessary to make up for the optical path of the laser within the first angle range to obtain the distance between the laser ranging system and the target, thereby improving the ranging accuracy and precision of the laser ranging system.

[0057] For example, when the laser emitted by the laser emitting unit 1 passes through the optical feedback component 4 and enters the laser receiving unit 2, the path S1 taken by the laser is S1 = (Δt3-Δt1-Δt2) × c, where Δt3 is the difference between the time when the processing chip stops timing and the time when the processing chip starts timing, that is, t2-t1. Δt1 is the difference between the time when the laser emitting unit 1 emits the laser and the time when the processing chip sends the driving electrical signal, that is, t3-t1. Δt2 is the difference between the time when the processing chip stops timing and the time when the laser receiving unit 2 receives the laser, that is, t2-t4. c is the speed of light.

[0058] The laser emitted by the laser emitting unit 1 passes through the target and enters the laser receiving unit 2. The path S2 taken by the laser is S2 = (Δt4-Δt1-Δt2) × c. Δt4 is the difference between the time when the processing chip stops timing and the time when the processing chip starts timing. Figure 3 The difference between Δt3, Δt4 and Δt3 lies in the different optical processes of the laser.

[0059] according to d is the distance between the laser ranging system and the target, L is the theoretical value of S1, which can be determined in advance, so that

[0060] Among them, Δt3 and Δt4 can be read from the laser ranging system, or the laser ranging system can obtain them in calculation, while Δt1 and Δt2 cannot be obtained by the laser ranging system.

[0061] It can be seen that the distance value measured by the laser ranging system can eliminate the time error generated in the process from the processing chip to the laser receiving part 1, and the time error generated in the process from the laser receiving part 2 to the processing chip, thereby improving the ranging accuracy.

[0062] Since the laser ranging system used in the above two processes is the same, the random errors generated by components such as the processing chip, the laser emitting unit 1 and the laser receiving unit 2 are also basically equal. Therefore, through the above-mentioned difference, the random errors generated by the components can be weakened or even eliminated, further improving the ranging accuracy.

[0063] In one example, the optical feedback component 4 may include a first reflector 41 and a second reflector 42. The laser emitting part 1, the first part 31 of the scanning mirror 3, and the first reflector 41 are located on the same side, and the first part 31 is located on the emission light path of the laser emitting part 1, and the first reflector 41 is located on the reflection light path of the first part 31. The laser receiving part 2, the second part 32 of the scanning mirror 3, and the second reflector 42 are located on the same side, and the second part 32 is located on the incident light path of the laser receiving part 2, the second reflector 42 is located on the incident light path of the second part 32, and the second reflector 42 is located on the reflection light path of the first reflector 41.

[0064] In this way, the laser emitted by the laser emitting unit 1 is incident on the reflecting surface of the first reflector 41 via the first part 31 of the scanning mirror 3. After being reflected by the reflecting surface of the first reflector 41, the laser is incident on the reflecting surface of the second reflector 42. After being reflected by the reflecting surface of the second reflector 42, the laser is incident on the second part 32 of the scanning mirror 3. The laser is then reflected by the second part 32 of the scanning mirror 3 to the laser receiving unit 2.

[0065] In one example, in order to prevent the laser emitted by the laser emitting unit 1 from entering the laser receiving unit 2 without passing through the optical feedback component 4 and the target, accordingly, Figure 1 As shown, the laser ranging system further includes a light blocking plate 5, wherein the light blocking plate 5 can also be called a light shielding plate, and is made of an opaque material. Figure 1As shown, the light baffle 5 divides the laser ranging system into an upper and lower side. For example, the laser emitting part 1, the first part 31 of the scanning mirror 3 and the first reflector 41 are located on one side of the light baffle 5, while the laser receiving part 2, the second part 32 of the scanning mirror 3 and the second reflector 42 are located on the other side of the light baffle 5.

[0066] Since the laser reflected by the reflective surface of the first reflector 41 can be incident on the second reflector 42, Figure 1 As shown, the light blocking plate 5 has a light hole 51 at a position corresponding to the reflection light path of the first reflector 41. In this way, the laser reflected by the reflection surface of the first reflector 41 can pass through the light hole 51 and be incident on the reflection surface of the second reflector 42.

[0067] As described above, the scanning mirror 3 includes a first part 31 and a second part 32, wherein the first part 31 and the second part 32 can be integrally formed, and the scanning mirror 3 passes through the light blocking plate 5, and is divided into the first part 31 and the second part 32 by the light blocking plate 5. Since the scanning mirror 3 can rotate, in order to prevent the light blocking plate 5 from interfering with the rotation of the scanning mirror 3, the light blocking plate 5 includes a rotating part 52 and a fixed part 53. For example, the fixed part 53 has a stepped through hole, and the rotating part 52 is located in the stepped through hole. In this way, the rotating part 52 can rotate relative to the fixed part 53, and the scanning mirror 3 passes through the rotating part 52. When the scanning mirror 3 rotates, it can drive the rotating part 52 to rotate synchronously, and then the light blocking plate 5 will not interfere with the rotation of the scanning mirror 3.

[0068] Of course, the first part 31 and the second part 32 of the scanning mirror 3 may also be independent of each other instead of being integrally formed. In this embodiment, the relationship between the first part 31 and the second part 32 of the scanning mirror 3 is not specifically limited, as long as they can achieve synchronous rotation.

[0069] In one example, if Figure 1 As shown, since the laser emitted by the laser emitting part 1 and the laser received by the laser receiving part 2 are coaxial in the vertical direction, the reflecting surface of the first reflector 41 and the reflecting surface of the second reflector 42 can also be mirror-symmetrical to ensure that the light passing through the upper and lower sides of the light blocking plate 5 is coaxial to avoid light spot distortion caused by different axes.

[0070] In an example, in order to make the light passing through the reflective surface of the first reflector 41 pass through the light hole 51 as much as possible and enter the second reflector 42, the reflective surface of the first reflector 41 is made of mirror material.

[0071] In one example, in order to allow the light passing through the reflective surface of the second reflector 42 to be incident on the laser receiving unit 2 via the second portion 32 of the scanning mirror 3, the reflective surface of the second reflector 42 is made of a diffuse reflective material. In this way, the light incident on the second reflector 42 is reflected in more directions, which expands the diameter of the light spot. Then, light at more angles can be incident on the laser receiving unit 2 via the scanning mirror 3, thereby increasing the probability that the laser receiving unit 2 receives the light, and thus making the signal received by the processing chip saturated, stable, and with small fluctuations.

[0072] In one example, in order for the laser receiving part 2 to receive the light reflected by the second reflector 42, the area of ​​the reflective surface of the second reflector 42 is not less than the interface diameter of the laser receiving part 2. This ensures that the light reflected by the second reflector 42 can enter the laser receiving part 2, so that all optical channels of the laser receiving part 2 can receive the light, and the stability of the received light is better.

[0073] In one example, in order to ensure that the first reflector 41 can receive the light reflected by the first part 31 of the scanning mirror 3 when the scanning mirror 3 rotates within the first angle range, accordingly, the area of ​​the reflective surface of the first reflector 41 needs to satisfy the requirement that the rotation angle range of the scanning mirror 3 is less than or equal to 5 degrees, and the first reflector 41 can receive the laser reflected by the scanning mirror 3. In this way, when the scanning mirror 3 rotates within the first angle range, there is always light passing through the second part 32 of the scanning mirror 3 and incident on the first reflector 41 for every 5 degrees of rotation.

[0074] Based on the above, when the laser ranging system measures the distance to the target, it calculates according to the time difference (i.e., Δt3, which can be recorded as the feedback time difference) between the laser emitted by the laser emitting part 1 and the laser receiving part 2 via the optical feedback component 4 when the scanning mirror 3 rotates within the first angle range, and the time difference (i.e., Δt4, which can be recorded as the ranging time difference) between the laser emitted by the laser emitting part 1 and the laser receiving part 2 via the target when the scanning mirror 3 rotates within the second angle range.

[0075] In one example, since the laser receiving part 2 is a detector array, the error generated by each detector may be different. Therefore, when measuring distance, the two time differences corresponding to the same detector can be used to calculate the distance value, which can eliminate the error generated by the current light channel and further improve the calculation accuracy.

[0076] In one example, in each frame measurement of the laser ranging system, the scanning mirror 3 can rotate both within the first angle range and within the second angle range, so that the feedback time difference Δt3 used in the measurement of each frame is an updated value.

[0077] In another example, when the external environment is stable and basically unchanged, the feedback time difference Δt3 may not be updated in real time. For example, the laser ranging system can update the feedback time difference Δt3 every few frames. For example, when the laser ranging system measures the distance in the first frame, the scanning mirror 3 rotates within the first angle range and the second angle range to determine the feedback time difference Δt3. When measuring the distance in the second frame, the scanning mirror 3 can only rotate within the second angle range, and the feedback time difference Δt3 determined in the previous frame is used when calculating the distance. This can improve the calculation efficiency.

[0078] In the embodiment of the present application, the laser ranging system includes not only a laser emitting unit, a laser receiving unit and a scanning mirror, but also an optical feedback component. When the scanning mirror rotates within a first angle range, the laser emitted by the laser emitting unit enters the laser receiving unit via the optical feedback component. When the scanning mirror rotates within a second angle range, the laser emitted by the laser emitting unit enters the laser receiving unit via the target to be measured. Whether the laser enters the laser receiving unit via the optical feedback component or via the target, the process from the processing chip to the laser emitting unit is exactly the same, and the processing process after entering the laser receiving unit is also exactly the same. Therefore, the error generated from the processing chip to the laser emitting unit and the error generated after the laser enters the laser receiving unit can be eliminated by subtracting the data within the first angle range and the data within the second angle range, thereby improving the measurement accuracy of the laser ranging system.

[0079] The above description is only an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present application shall be included in the protection scope of the present application.

Claims

1. A laser ranging system, characterized in that: The laser distance measurement system comprises a laser emitting unit (1), a laser receiving unit (2), a scanning mirror (3), an optical feedback component (4) and a light blocking plate (5); The laser emitting portion (1) is located on a first side in the thickness direction of the light blocking plate (5), and the laser receiving portion (2) is located on a second side in the thickness direction of the light blocking plate (5); The scanning mirror (3) passes through the light blocking plate (5) along the thickness direction of the light blocking plate (5); the first part (31) of the scanning mirror (3) is located on the first side of the light blocking plate (5); the second part (32) of the scanning mirror (3) is located on the second side of the light blocking plate (5); and the rotation axis of the scanning mirror (3) is perpendicular to the light blocking plate (5); The optical feedback assembly (4) comprises a first reflector (41) and a second reflector (42), wherein the first reflector (41) is located on a first side of the light blocking plate (5), the second reflector (42) is located on a second side of the light blocking plate (5), and the second reflector (42) is located on a reflected light path of the first reflector (41), and the light blocking plate (5) has a light through hole (51) on the light path corresponding to the first reflector (41) and the second reflector (42); When the scanning mirror (3) rotates within a first angle range, the first reflection surface of the first part (31) is located on the outgoing light path of the laser emitting part (1) and on the incident light path of the first reflector (41), and the first reflection surface of the second part (32) is located on the receiving light path of the laser receiving part (2) and on the reflecting light path of the second reflector (42); When the scanning mirror (3) rotates within a second angle range, the second reflection surface of the first part (31) is located on the outgoing light path of the laser emitting part (1), and the reflection light path of the second reflection surface of the first part (31) and the incident light path of the second reflection surface of the second part (32) are both oriented toward a target to be measured, wherein the first reflection surface and the second reflection surface are positioned relative to each other along the thickness direction of the scanning mirror (3).

2. The laser ranging system according to claim 1, characterized in that: The light blocking plate (5) comprises a rotating part (52) and a fixed part (53); the scanning mirror (3) passes through the rotating part (52), and the rotating part (52) can rotate synchronously with the scanning mirror (3).

3. The laser ranging system according to claim 1, characterized in that: The reflecting surface of the first reflecting member (41) and the reflecting surface of the second reflecting member (42) are mirror-symmetrical.

4. The laser ranging system according to claim 1, characterized in that: The reflective surface of the first reflective element (41) is made of a mirror material.

5. The laser ranging system according to claim 1, characterized in that: The reflective surface of the second reflective element (42) is made of a diffuse reflective material.

6. The laser ranging system according to claim 1, characterized in that: The area of ​​the reflection surface of the first reflector (41) satisfies that the rotation angle range of the scanning mirror (3) is less than or equal to 5 degrees, and the first reflector (41) can receive the laser reflected by the scanning mirror (3).

7. The laser ranging system according to claim 1, characterized in that: The area of ​​the reflection surface of the second reflector (42) is not less than the receiving aperture of the laser receiving part (2).

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