Rotating mirror for laser radar and manufacturing method thereof

Abstract

The invention relates to a rotating mirror for a laser radar and a manufacturing method thereof, and the method comprises the following steps: firstly, providing a blank which is of a regular prism-shaped structure and is provided with a containing groove, and the opening of the containing groove is formed in the top surface and / or the bottom surface of the blank; then carrying out surface grinding and polishing treatment on the blank to obtain a prefabricated rotating mirror; and finally forming a plurality of reflecting surfaces on the side surface of the prefabricated rotating mirror to obtain the rotating mirror. According to the manufacturing method of the rotating mirror for the laser radar, the blank is subjected to surface grinding and polishing treatment, the multiple reflecting surfaces are formed on the side face of the prefabricated rotating mirror, the formed rotating mirror can be suitable for signal reflection operation in a large temperature difference environment, the rotation precision of the multiple reflecting surfaces can be improved, the manufacturing method of the rotating mirror is simple, and the manufacturing cost is low. The assembly process between the rotating mirror and the motor is simple and convenient.

Description

Technical Field

[0001] The present application relates to the field of sensor technology, and in particular to a rotating mirror for laser radar and a method for manufacturing the same. Background Art

[0002] With the widespread application of advanced driver assistance and autonomous driving, road condition perception sensor technologies such as LiDAR, millimeter wave radar, and vehicle-mounted cameras are developing rapidly. With the increasing demand for the degree of autonomous driving of vehicles, vehicle-mounted LiDAR, which has many advantages such as more accurate environmental perception and stronger anti-interference ability, is gaining more and more attention from various automobile OEMs.

[0003] In the related technology, "semi-solid laser radar" is often used to replace the traditional "mechanical radar" installed on the vehicle. In the "semi-solid laser radar", the transmitting device and the receiving device are fixed, and the laser scanning is realized by driving one or more reflectors to rotate by the motor. Since the "semi-solid laser radar" is formed by bonding multiple reflectors to a metal bracket, and then fixing the metal bracket to the motor rotor, it is difficult to ensure the assembly tolerance between the multiple reflectors and the metal bracket, and the relative position relationship between the multiple reflectors and the motor rotor is prone to large deviations; and the vehicle-mounted laser radar often needs to work in a large temperature difference environment. Since the linear expansion coefficients of the reflector and the metal bracket are quite different, when the temperature changes, the stress generated by the deformation of the metal bracket is easy to cause the reflector to crack, collapse and other undesirable phenomena, and the risk of cracking and debonding of the bonding point between the reflector and the metal bracket is prone to occur; in addition, the amount of bonding glue and the bonding position between the reflector and the metal bracket are difficult to control, resulting in a complex and difficult assembly process between the reflector and the metal bracket. Summary of the invention

[0004] Based on this, it is necessary to provide a rotating mirror for laser radar and a method for manufacturing it, in order to address the problems that the relative position relationship between multiple mirrors and the motor rotor in existing semi-solid laser radars is prone to large deviations, is not suitable for working in environments with large temperature differences, and the assembly process between the mirrors and the metal bracket is complex and difficult.

[0005] A method for manufacturing a rotating mirror for a laser radar comprises the following steps:

[0006] S101: providing a blank, wherein the blank is a regular prism-shaped structure, and the blank has a receiving groove for connecting an output shaft of a motor, and the receiving groove opens on a top surface and / or a bottom surface of the blank;

[0007] S102: performing surface grinding and polishing treatment on the blank to obtain a prefabricated rotating mirror, wherein the prefabricated rotating mirror has a side surface parallel to the axis direction of the motor output shaft;

[0008] S103: forming a plurality of reflective surfaces on the side surface of the prefabricated rotating mirror to obtain the rotating mirror.

[0009] In one embodiment, in step S101:

[0010] The blank is formed by sintering ceramics.

[0011] In one of the embodiments, the surface roughness of the prefabricated rotating mirror is Ra0.012, and the surface flatness of the prefabricated rotating mirror is less than or equal to 150 nm.

[0012] In one embodiment, the step S103 is specifically:

[0013] An optical reflective film is formed on the side surface of the prefabricated rotating mirror by coating, so as to form a plurality of reflective surfaces on the side surface of the prefabricated rotating mirror, thereby obtaining the rotating mirror.

[0014] In one embodiment, the optical reflective film is a gold film or a silver film.

[0015] In one embodiment, the receiving groove is a cylindrical groove, and the step S102: performing surface grinding and polishing on the blank to obtain a prefabricated rotating mirror, the prefabricated rotating mirror having a side parallel to the axial direction of the motor output shaft also includes: grinding the receiving groove so that the cylindricity of the receiving groove is less than or equal to 5μm, and the surface roughness of the inner wall of the receiving groove is Ra0.6.

[0016] In one of the embodiments, in the step S101, a process groove is formed on the side of the blank formed by sintering away from the receiving groove, and one of the process groove and the receiving groove opens at the top surface, and the other opens at the bottom surface.

[0017] In one of the embodiments, in the step S101, a spacer is formed on the blank after sintering, the spacer is located between the receiving groove and the process groove, and a screw hole is formed on the spacer that penetrates the thickness of the spacer.

[0018] A rotating mirror for laser radar, the rotating mirror comprising a rotating mirror body, a receiving groove formed on the rotating mirror body and a plurality of reflecting surfaces, the rotating mirror body being in the shape of a regular prism, the rotating mirror body comprising an opposite top surface, a bottom surface and a side surface connecting the top surface and the bottom surface, a plurality of reflecting surfaces being formed on the side surface, the receiving groove opening at the top surface and / or the bottom surface of the rotating mirror, the receiving groove being an axisymmetric structure, the symmetry axis of the receiving groove overlapping with the central axis of the rotating mirror body and being parallel to the side surface.

[0019] In one embodiment, the rotating mirror body is made of ceramic material, and the rotating mirror body is an integral sintered structure.

[0020] In one embodiment, the accommodating groove is a cylindrical groove and is located on the bottom surface of the rotating mirror body. The cylindrical groove does not penetrate the bottom surface and the top surface of the rotating mirror body. A screw hole is provided on the top surface opposite to the cylindrical groove. The aperture of the screw hole is smaller than that of the cylindrical groove and is connected to the cylindrical groove.

[0021] The above-mentioned rotating mirror for laser radar and its manufacturing method, by performing surface grinding and polishing treatment on the blank, a prefabricated rotating mirror is obtained, and multiple reflecting surfaces are formed on the side of the prefabricated rotating mirror. Since the linear expansion coefficients between the reflecting surface and the blank are consistent, the formed rotating mirror can be suitable for signal reflection operations in an environment with a large temperature difference. When the output shaft of the motor is inserted into the accommodating groove, the coaxiality between the rotation axes of the multiple reflecting surfaces and the rotation axis of the motor can be guaranteed to improve the rotation accuracy of the multiple reflecting surfaces. The manufacturing method of the rotating mirror is simple, and the assembly process between the rotating mirror and the motor is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a flowchart of a method for manufacturing a rotating mirror used in a laser radar in some embodiments.

[0023] Figure 2 Schematic diagram of the structure of the rotating mirror and motor component module in some embodiments.

[0024] Figure 3 It is a schematic diagram of the structure of another viewing angle of the rotating mirror in some embodiments.

[0025] Figure 4 It is a schematic diagram of the exploded structure of the rotating mirror and motor component module in some embodiments.

[0026] Reference numerals:

[0027] 100. Rotate the mirror;

[0028] 110, blank; 111, receiving groove; 112, top surface; 113, bottom surface; 114, side surface; 115, reflecting surface; 116, process groove; 117, spacer; 118, screw hole; 120, screw connection;

[0029] 200. Motor. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0031] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0032] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0033] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0034] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0035] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0036] The technical solution provided by the embodiments of the present application is described below in conjunction with the accompanying drawings.

[0037] like Figure 1-Figure 3 As shown, the present application provides a method for manufacturing a rotating mirror 100 for a laser radar, and the method for manufacturing a rotating mirror 100 for a laser radar comprises the following steps:

[0038] Step S101: Provide a blank 110, the blank 110 is a regular prism-shaped structure, the blank 110 has a receiving groove 111 for connecting the output shaft of the motor 200, and the receiving groove 111 opens on the top surface 112 and / or the bottom surface 113 of the blank 110. Specifically, in the present embodiment, the blank 110 can be a regular triangular prism, a regular quadrangular prism, a regular pentagonal prism or other regular prism structures. It should be noted that the regular prism structure in the present embodiment is to achieve a geometrically regular prism structure as much as possible, and is an industrial regular prism, rather than a geometrically perfect regular prism. The blank 110 is surrounded by a top surface 112, a bottom surface 113, and a side surface 114 connecting the top surface 112 and the bottom surface 113, and the top surface 112 and the bottom surface 113 are respectively located on opposite sides of the blank 110. Furthermore, chamfering, hollowing, and other designs can be made on the blank 110 to make the blank 110 lightweight, and when the rotating mirror 100 is connected to other structures, the blank 110 can play a role in structural avoidance. In addition, the structure of the receiving groove 111 is integrally formed with the blank 110 by sintering, injection molding, etc., to simplify the forming process of the blank 110 and the receiving groove 111, saving the manufacturing cost of the blank 110 and the receiving groove 111, and the output shaft of the motor 200 can be arranged in the receiving groove 111 by inserting, embedding, etc., to achieve the connection between the blank 110 and the motor 200.

[0039] Step S102: Grind and polish the surface of the blank 110 to obtain a prefabricated rotating mirror. Specifically, a polishing cloth, fine sandpaper, etc. can be used to grind and polish the surface of the blank 110 so that the surface roughness, flatness, and other process requirements of the blank 110 surface meet the established requirements. The prefabricated rotating mirror has a side 114 parallel to the axis direction of the output shaft of the motor 200. It should be noted that if the prefabricated rotating mirror after grinding and polishing is a regular triangular prism, the side 114 is at an acute angle or an obtuse angle to the axis direction of the output shaft of the motor 200.

[0040] Step S103: forming a plurality of reflective surfaces 115 on the side surface 114 of the prefabricated rotating mirror to obtain the rotating mirror 100. As in the present embodiment, an optical reflective film may be formed on the side surface 114 of the prefabricated rotating mirror by coating, so as to form a plurality of reflective surfaces 115 on the side surface 114 of the prefabricated rotating mirror to obtain the rotating mirror 100. For example, a liquid gold layer or a liquid silver layer may be coated on the side surface 114 of the prefabricated rotating mirror, and an optical reflective film may be formed on the side surface 114 of the prefabricated rotating mirror after the liquid gold layer or the liquid silver layer is solidified, or gold particles or silver particles may be deposited on the side surface 114 of the prefabricated rotating mirror to form an optical reflective film on the side surface 114 of the prefabricated rotating mirror, that is, the optical reflective film is a gold film or a silver film. Since both the gold film and the silver film have high reflectivity, for example, within the working laser band and under the condition that the incident angle is within the range of 15°-75°, the average reflectivity of the gold film and the silver film can reach more than 99.5%. After the gold film or the silver film is coated / deposited on the side surface 114 of the prefabricated rotating mirror, multiple reflective surfaces 115 can be formed on the side surface 114 of the prefabricated rotating mirror. Of course, in other feasible embodiments, the optical reflective film can also be an aluminum film, which can reduce the manufacturing cost of the rotating mirror 100 while ensuring that the reflective surface 115 has a high reflectivity. In addition, if the blank 110 is a regular triangular prism, three reflective surfaces 115 can be formed on the side surface 114 of the prefabricated rotating mirror; if the blank 110 is a regular quadrangular prism, four reflective surfaces 115 can be formed on the side surface 114 of the prefabricated rotating mirror; if the blank 110 is a regular pentagonal prism, five reflective surfaces 115 can be formed on the side surface 114 of the prefabricated rotating mirror. Of course, in other feasible embodiments, the blank 110 can also be other regular prism structures, and after the blank 110 is subjected to surface grinding and polishing, other number of reflecting surfaces 115 are formed on the side surface 114 of the prefabricated rotating mirror. When the light signal acts on the reflecting surface 115, the reflecting surface 115 can perform a signal reflection operation.

[0041] The manufacturing method of the rotating mirror 100 is to obtain a prefabricated rotating mirror by grinding and polishing the surface of the blank 110, and to form an optical reflective film on the side 114 of the prefabricated rotating mirror, so that a plurality of reflective surfaces 115 can be formed on the side 114 of the prefabricated rotating mirror. Since the plurality of reflective surfaces 115 are integrally formed on the surface of the blank 110, the linear expansion coefficients of the reflective surfaces 115 and the blank 110 are consistent, and the formed rotating mirror 100 can be applied to signal reflection operations in a large temperature difference environment. When the output shaft of the motor 200 is inserted into the accommodating groove 111, the motor 200 drives the synchronous rotation of the plurality of reflective surfaces 115, which can ensure the coaxiality between the rotation axes of the plurality of reflective surfaces 115 and the rotation axis of the motor 200, so as to improve the rotation accuracy of the plurality of reflective surfaces 115, and change the direction of the detection signal and the echo signal during the rotation of the plurality of reflective surfaces 115. The angle range between two adjacent reflective surfaces 115 is the detection viewing angle of the laser radar. Furthermore, the manufacturing method of the rotating mirror 100 is simple, and the assembly process between the rotating mirror 100 and the motor 200 is simple.

[0042] In order to simplify the molding process of the rotating mirror 100, in one embodiment, Figure 1 and Figure 2 As shown, in step S101: the blank 110 is formed by sintering ceramics. Specifically, in this embodiment, the ceramic powder material can be filled into a special mold, and the ceramic powder material is placed under a set temperature condition for sintering to integrally form the blank 110. The above-mentioned blank 110 is formed in a simple manner, so as to simplify the forming process of the rotating mirror 100, save the manufacturing cost of the rotating mirror 100, and ensure the integrity of the rotating mirror 100 after forming.

[0043] Of course, in other feasible embodiments, the blank 110 may also be made of iron-based powder metallurgy or glass sintering, or the blank 110 may be injection molded of engineering plastics, and the blank 110 may also be integrally molded.

[0044] In order to complete the molding process of the prefabricated rotating mirror, in one embodiment, as Figure 1 and Figure 2 As shown, the blank 110 is subjected to surface grinding and polishing to obtain a prefabricated rotating mirror, and the surface roughness of the prefabricated rotating mirror is Ra0.012, and the surface flatness of the prefabricated rotating mirror is less than or equal to 150nm, so as to ensure the surface finish and flatness of the prefabricated rotating mirror after molding. In the manufacturing method of the rotating mirror 100, the surface roughness and surface flatness of the prefabricated rotating mirror are set to be relatively small, so that in the subsequent process of forming the optical reflective film on the side surface 114 of the prefabricated rotating mirror, the coating or deposition flatness of the optical reflective film is better, so as to improve the coating or deposition effect of the optical reflective film, thereby ensuring the molding quality of the multiple reflective surfaces 115, so as to improve the signal reflection accuracy of the multiple reflective surfaces 115.

[0045] In order to further improve the signal reflection accuracy of the multiple reflection surfaces 115, in one embodiment, Figure 2 and Figure 3 As shown, when the output shaft of the motor 200 is inserted into the receiving groove 111, the motor 200 is connected to the blank 110, and the motor 200 can drive the rotation of the multiple reflective surfaces 115, so that the multiple reflective surfaces 115 can perform laser scanning operations, and the angle between the rotation axis of the multiple reflective surfaces 115 and the rotation axis of the motor 200 is less than or equal to 0.025°. Since the angle between the rotation axis of the multiple reflective surfaces 115 and the rotation axis of the motor 200 directly affects the directivity of the reflected signal light, when the output shaft of the motor 200 is inserted into the receiving groove 111, the angle between the rotation axis of the multiple reflective surfaces 115 and the rotation axis of the motor 200 is maintained at a smaller value as much as possible, which can further improve the signal reflection accuracy of the multiple reflective surfaces 115.

[0046] It should be noted that, conventionally, when the output shaft of the motor is connected to a bracket on which a plurality of reflectors are installed by screwing, clamping, etc., due to a series of uncertain factors in the process of processing errors or manual installation, it is impossible to ensure that the rotation axis of the plurality of reflectors is completely coaxial with the rotation axis of the motor. In order to improve the signal reflection accuracy of the plurality of reflective surfaces 115, in this embodiment, the blank 110 is integrally formed with a receiving groove 111, and when the output shaft of the motor 200 is inserted into the receiving groove 111, it can be ensured that the angle between the rotation axis of the plurality of reflective surfaces 115 and the rotation axis of the output shaft of the motor 200 is less than or equal to 0.025°, so that the angle between the rotation axis of the plurality of reflective surfaces 115 and the rotation axis of the motor 200 is kept within a relatively small difference range as much as possible. In the above connection method, the receiving groove 111 can guide and locate the installation position of the motor 200, significantly reducing the undesirable phenomenon that the rotation axis of the plurality of reflective surfaces 115 and the rotation axis of the motor 200 deviate too much due to the existence of manual installation errors.

[0047] Furthermore, if Figure 2 and Figure 3 As shown, the receiving groove 111 is a cylindrical groove, and step S102 also includes: grinding the receiving groove 111 so that the cylindricality of the receiving groove 111 is less than or equal to 5μm, and the inner wall surface roughness of the receiving groove 111 is Ra0.6. When the output shaft of the motor 200 is inserted into the receiving groove 111, the processing accuracy of the receiving groove 111 will directly affect the relative position accuracy between the motor 200 and the multiple reflective surfaces 115. The cylindricality and the inner wall surface roughness of the receiving groove 111 are set to be smaller, so that the motor 200 can be installed behind the rotating mirror 100 to prevent the motor 200 from tilting, so that the angle between the rotation axis of the multiple reflective surfaces 115 and the rotation axis of the motor 200 is less than or equal to 0.025°, thereby improving the signal reflection accuracy of the multiple reflective surfaces 115.

[0048] In order to simplify the assembly process between the rotating mirror 100 and the motor 200, in one embodiment, Figure 2 and Figure 3As shown, in step S101, the blank 110 after sintering is formed with a process groove 116 on the side away from the receiving groove 111, that is, the process groove 116 is integrally formed inside the blank 110 by sintering, and one of the process groove 116 and the receiving groove 111 is opened at the top surface 112, and the other of the process groove 116 and the receiving groove 111 is opened at the bottom surface 113. In other words, the process groove 116 and the receiving groove 111 are respectively opened at two opposite sides of the blank 110, such as when the process groove 116 is opened at the top surface 112, the receiving groove 111 is opened at the bottom surface 113; and when the process groove 116 is opened at the bottom surface 113, the receiving groove 111 is opened at the top surface 112. The process groove 116 can be used as an operating space for connecting the motor 200 to the rotating mirror 100, which is convenient for the operator to connect the motor 200 to the rotating mirror 100, so as to simplify the assembly process between the rotating mirror 100 and the motor 200.

[0049] Furthermore, if Figure 3 and Figure 4 As shown, in step S101, the blank 110 formed by sintering is also formed with a spacer 117, that is, the spacer 117 is integrally formed inside the blank 110 by sintering. The spacer 117 is located between the receiving groove 111 and the process groove 116, that is, the receiving groove 111 and the process groove 116 are respectively arranged on two opposite sides of the spacer 117. The spacer 117 is formed with a screw hole 118, and the screw hole 118 passes through the thickness direction of the spacer 117 to connect the receiving groove 111 and the process groove 116. In this embodiment, when the motor 200 needs to be connected to the rotating mirror 100, the operator positions the output shaft of the motor 200 and inserts it into the receiving groove 111, and extends it into the process groove 116 with the help of an auxiliary tool. The auxiliary tool locks the motor 200 on the spacer 117 through the screw connector 120, and the motor 200 can be locked on the rotating mirror 100, completing the assembly connection between the motor 200 and the rotating mirror 100. In addition, the process groove 116 can prevent the screw connector 120 from protruding outside the rotating mirror 100 to ensure the structural integrity of the rotating mirror 100 and the motor 200 after assembly. It should be noted that in this embodiment, the receiving groove 111, the screw hole 118 and the blank 110 are formed by sintering ceramics to simplify the molding process of the rotating mirror 100.

[0050] Of course, in other feasible embodiments, the output shaft of the motor 200 can also be directly inserted into the receiving groove 111 by gluing, tight fitting, etc., and the assembly connection between the motor 200 and the rotating mirror 100 can also be completed. As for which method is used to achieve the assembly connection between the motor 200 and the rotating mirror 100, it can be specifically set according to process requirements, etc., and this application does not limit it.

[0051] In order to ensure that the rotation axis of the motor 200 and the rotation axis of the plurality of reflection surfaces 115 have a high degree of coaxiality after assembly, specifically, as Figure 2As shown, after the blank 110 is subjected to surface grinding and polishing, the surface roughness of the spacer 117 is Ra0.6, and the surface flatness of the spacer 117 is less than or equal to 5μm. The surface roughness and flatness of the spacer 117 are set to be relatively small, so as to prevent the motor 200 from tilting due to the influence of the spacer 117 during the assembly process, so as to ensure the relative position accuracy between the motor 200 and the multiple reflection surfaces 115, that is, to ensure that the rotation axis of the motor 200 and the rotation axis of the multiple reflection surfaces 115 have a high coaxiality after assembly, thereby improving the signal reflection accuracy of the multiple reflection surfaces 115.

[0052] In addition, if Figure 2 and Figure 3 As shown, the present application also provides a rotating mirror 100 for laser radar. The rotating mirror 100 is obtained by the manufacturing method of the rotating mirror 100 for laser radar of any one of the above technical solutions. The rotating mirror 100 includes a rotating mirror body, a receiving groove 111 formed on the rotating mirror body, and a plurality of reflecting surfaces 115. Among them, the rotating mirror body is in the shape of a regular prism, and the rotating mirror body includes a relative top surface 112, a bottom surface 113 and a side surface 114, and the side surface 114 connects the top surface 112 and the bottom surface 113, that is, the rotating mirror body is surrounded by the top surface 112, the bottom surface 113 and the side surface 114. The output shaft of the motor 200 can be inserted into the receiving groove 111 to connect the motor 200 to the rotating mirror 100. The motor 200 is used to drive the rotation of the rotating mirror 100, and realize the laser scanning operation through the rotation of the rotating mirror 100. Multiple reflective surfaces 115 are formed on the side surface 114, and the receiving groove 111 opens on the top surface 112 and / or the bottom surface 113 of the rotating mirror 100. The receiving groove 111 is an axisymmetric structure. The symmetry axis of the receiving groove 111 overlaps with the central axis of the rotating mirror body, and the symmetry axis of the receiving groove 111 is parallel to the side surface 114. When the output shaft of the motor 200 is inserted into the receiving groove 111, the angle between the rotation axis of the multiple reflective surfaces 115 and the rotation axis of the motor 200 is maintained at a smaller value as much as possible to improve the signal reflection accuracy of the multiple reflective surfaces 115.

[0053] Among them, in this embodiment, if Figure 2 As shown, the rotating mirror body is made of ceramic material and is an integral sintered structure. The molding method of the rotating mirror body is simple, which simplifies the molding process of the rotating mirror 100, saves the manufacturing cost of the rotating mirror 100, and can ensure the integrity of the rotating mirror 100 after molding.

[0054] And, if Figure 2-Figure 4As shown, the receiving groove 111 is a cylindrical groove, and the receiving groove 111 is located on the bottom surface 113 of the rotating mirror body, and the cylindrical groove does not penetrate the bottom surface 113 and the top surface 112 of the rotating mirror body at the same time. The rotating mirror 100 is provided with a screw hole 118 on the top surface 112 opposite to the cylindrical groove, and the hole diameter of the screw hole 118 is smaller than the inner diameter of the cylindrical groove, and the screw hole 118 is connected to the cylindrical groove, and the motor 200 can be locked on the rotating mirror 100 through the screw hole 118, completing the assembly connection between the motor 200 and the rotating mirror 100.

[0055] The rotating mirror 100 for laser radar can be applied to signal reflection operations in environments with large temperature differences, and can ensure the coaxiality between the rotation axes of the multiple reflecting surfaces 115 and the rotation axes of the motor 200, so as to improve the rotation accuracy of the multiple reflecting surfaces 115. The manufacturing method of the rotating mirror 100 is simple, and the assembly process between the rotating mirror 100 and the motor 200 is simple.

[0056] Furthermore, if Figure 2 and Figure 4 As shown, the present application also provides a laser radar (not shown in the figure), which includes a laser transmitting module (not shown in the figure), a laser receiving module (not shown in the figure) and at least one rotating mirror 100. The output shaft of the motor 200 is connected to the rotating mirror 100, and the motor 200 is used to drive the rotation of the rotating mirror 100. The laser transmitting module is used to send out a detection signal, and the laser receiving module is used to receive an echo signal formed after the detection signal is reflected by the rotating mirror 100, that is, the laser transmitting signal can send out a detection signal, and after being reflected by the rotating mirror 100, it forms an echo signal for the laser receiving module to receive.

[0057] In the above-mentioned laser radar, the detection signal emitted by the laser emission module reaches the detection object after being reflected by one or more rotating mirrors 100, and forms an echo signal after being reflected by the detection object. The echo signal reaches the laser receiving module after being reflected by the rotating mirror 100 to scan the position information of the detection object. The laser radar provided by the present application has a plurality of reflection surfaces 115 integrally formed on the surface of the blank 110, and the linear expansion coefficients between the reflection surface 115 and the blank 110 are consistent. The formed rotating mirror 100 can be applied to signal reflection operations in an environment with a large temperature difference. When the output shaft of the motor 200 is inserted into the accommodating groove 111, the coaxiality between the rotation axes of the plurality of reflection surfaces 115 and the rotation axes of the motor 200 can be ensured to improve the rotation accuracy of the plurality of reflection surfaces 115. In addition, the manufacturing method of the rotating mirror 100 is simple, and the assembly process of the laser radar is simple.

[0058] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0059] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A method for manufacturing a rotating mirror for a laser radar, characterized in that: The following steps are involved: S101: providing a blank, wherein the blank is a regular prism-shaped structure, and the blank has a receiving groove for connecting an output shaft of a motor, and the receiving groove opens on a top surface and / or a bottom surface of the blank; S102: performing surface grinding and polishing treatment on the blank and grinding the containing groove to obtain a prefabricated rotating mirror, wherein the prefabricated rotating mirror has a side surface parallel to the axis direction of the motor output shaft; S103: forming a plurality of reflective surfaces on the side surface of the prefabricated rotating mirror to obtain the rotating mirror.

2. The method for manufacturing a rotating mirror for a laser radar according to claim 1, characterized in that: In step S101: The blank is formed by sintering ceramics.

3. The method for manufacturing a rotating mirror for a laser radar according to claim 1, characterized in that: The surface roughness of the prefabricated rotating mirror is Ra0.012, and the surface flatness of the prefabricated rotating mirror is less than or equal to 150nm.

4. The method for manufacturing a rotating mirror for a laser radar according to claim 1, characterized in that: The step S103 is specifically as follows: An optical reflective film is formed on the side surface of the prefabricated rotating mirror by coating, so as to form a plurality of reflective surfaces on the side surface of the prefabricated rotating mirror, thereby obtaining the rotating mirror.

5. The method for manufacturing a rotating mirror for a laser radar according to claim 4, characterized in that: The optical reflective film is a gold film or a silver film.

6. The method for manufacturing a rotating mirror for a laser radar according to claim 1, characterized in that: The receiving groove is a cylindrical groove, and the step S102: performing surface grinding and polishing on the blank to obtain a prefabricated rotating mirror, the prefabricated rotating mirror having a side parallel to the axial direction of the motor output shaft also includes: grinding the receiving groove so that the cylindricity of the receiving groove is less than or equal to 5μm, and the surface roughness of the inner wall of the receiving groove is Ra0.

6.

7. The method for manufacturing a rotating mirror for laser radar according to claim 1, characterized in that: In the step S101 , a process groove is formed on the side of the sintered blank away from the receiving groove, and one of the process groove and the receiving groove is opened at the top surface, and the other of the two is opened at the bottom surface.

8. The method for manufacturing a rotating mirror for a laser radar according to claim 7, characterized in that: In the step S101 , a spacer is formed on the blank after sintering. The spacer is located between the receiving groove and the process groove, and a screw hole penetrating through the thickness of the spacer is formed on the spacer.

9. A rotating mirror for laser radar, characterized in that: The rotating mirror includes a rotating mirror body, a receiving groove formed on the rotating mirror body and a plurality of reflecting surfaces. The rotating mirror body is in the shape of a regular prism. The rotating mirror body includes a relative top surface, a bottom surface and a side surface connecting the top surface and the bottom surface. A plurality of reflecting surfaces are formed on the side surface. The receiving groove opens to the top surface and / or the bottom surface of the rotating mirror. The receiving groove after grinding is an axisymmetric structure. The symmetry axis of the receiving groove overlaps with the central axis of the rotating mirror body and is parallel to the side surface.

10. The rotating mirror for laser radar according to claim 9, characterized in that: The rotating mirror body is made of ceramic material and is an integral sintered structure.

11. The rotating mirror for laser radar according to claim 10, characterized in that: The accommodating groove is a cylindrical groove and is located on the bottom surface of the rotating mirror body. The cylindrical groove does not penetrate the bottom surface and the top surface of the rotating mirror body. A screw hole is provided on the top surface opposite to the cylindrical groove. The aperture of the screw hole is smaller than that of the cylindrical groove and is connected to the cylindrical groove.

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