An angle measuring device, a detection device and a vehicle

Abstract

The application relates to the technical field of detection, in particular to an angle measuring device, a detection device and a vehicle. The angle measuring device comprises at least two encoders and a code disc, the code disc is arranged on a rotating shaft, a rotating mirror is arranged on the rotating shaft, the code disc and the rotating mirror rotate synchronously based on the rotating shaft, and the at least two encoders are uniformly distributed based on the rotating shaft. The rotating angle of the code disc is detected by the at least two encoders, so that the measurement error of the rotating angle of the code disc is reduced, the measurement error of the rotating angle of the rotating mirror is reduced, and the accuracy of the rotating angle measurement of the rotating mirror is improved. The rotating mirror comprises at least two mirror surfaces, the number of the encoders is greater than or equal to the number of the mirror surfaces of the rotating mirror, and the accuracy of the rotating angle measurement of the rotating mirror is improved by arranging more encoders.

Description

Technical Field

[0001] This application relates to the field of detection technology, and in particular to an angle measuring device, a detection device, and a vehicle. Background Technology

[0002] LiDAR (Light Detection and Ranging) is a commonly used detection technology that is widely applied in various fields such as autonomous driving, driver assistance, and object recognition.

[0003] Currently, LiDAR scanning is generally accomplished by a rotating mirror. Specifically, the mirror is mounted on a motor shaft. As the mirror rotates, probe light is incident on the mirror surface, which reflects the light. As the mirror rotates, the angle of incidence of the probe light on the mirror changes, and consequently, the angle of the reflected light also changes, thus forming a grating and achieving laser scanning. During the scanning process, the mirror's rotation angle is used to generate a point cloud to detect the target's position. Therefore, measuring the mirror's rotation angle is particularly important.

[0004] The rotation angle of the rotating mirror is generally obtained by an encoder detecting the code disk. The code disk and the rotating mirror are coaxially set, which means that the assembly error between the code disk and the motor shaft (large concentricity, skewness, nonlinearity, etc.) directly affects the accuracy of the rotation angle measurement. Therefore, how to improve the accuracy of the rotating mirror rotation angle measurement is an urgent technical problem to be solved. Utility Model Content

[0005] This application provides an angle measuring device, a detection device, and a vehicle to reduce the measurement error of the rotation angle of a rotating mirror and improve the accuracy of the rotation angle measurement.

[0006] In a first aspect, this application provides an angle measuring device, including at least two encoders and a code disk, the code disk being disposed on a rotating shaft, a rotating mirror being disposed on the rotating shaft, and the code disk and the rotating mirror rotating synchronously based on the rotating shaft, and the at least two encoders being evenly distributed based on the rotating shaft.

[0007] In the above scheme, at least two encoders measure one code disk; in other words, each of the at least two encoders measures the same code disk. Based on this, using at least two encoders to detect the code disk rotation angle reduces the measurement error of the code disk rotation angle, thereby reducing the measurement error of the rotating mirror rotation angle and improving the accuracy of the rotating mirror rotation angle measurement. Furthermore, the at least two encoders are evenly distributed along the rotating shaft to ensure the balance of the code disk rotation angle detection by the at least two encoders, further reducing the measurement error of the rotating mirror rotation angle.

[0008] One possible design is that the rotating mirror includes at least two mirrors, the included angle between any two adjacent mirrors is the same, and the number of at least two encoders is greater than or equal to the number of mirrors of the rotating mirror.

[0009] In this design, considering that the more mirrors a rotating mirror has, the greater the impact of the assembly error between the encoder and the rotating shaft on the accuracy of the rotating mirror's rotation angle measurement, a larger number of encoders are used to improve the accuracy of the rotating mirror's rotation angle measurement.

[0010] One possible design is that the rotation angle of the rotating mirror is the average of the rotation angles of at least two code disks, or the rotation angle of the rotating mirror is the weighted average of the rotation angles of at least two code disks; wherein the weights corresponding to the at least two encoders are positively correlated with the angle detection accuracy, and the at least two code disk rotation angles are obtained based on the at least two encoders.

[0011] In this design, encoders are used to detect the code disk rotation angle. Each encoder yields a corresponding code disk rotation angle, resulting in at least two rotation angles. These two angles are used to determine the rotation angle of the rotating mirror. Generally, due to assembly errors between the code disk and the shaft, the rotation angles of any two encoders will be different. In other words, the rotation angle of each encoder has an error angle, and is not accurate (or ideal). Specifically, these error angles are either positive or negative compared to the ideal code disk rotation angle (i.e., the rotation angle measured when there are no assembly errors between the code disk and the shaft). Therefore, the measurement error of the code disk rotation angle is neutralized by averaging or weighted averaging to reduce the measurement error of the rotating mirror rotation angle, thereby improving the accuracy of the rotating mirror rotation angle measurement.

[0012] One possible design is that the eccentricity between the center of the code disk and the center of the rotating shaft is e, where e is greater than 0, and the distance between any one of the two encoders and the center of the code disk is R, where R is greater than 0.

[0013] In this design, the eccentricity e represents the degree of assembly error between the code disk and the shaft. Since the encoder is based on the code disk, the distance between any one of the two encoders and the center of the code disk is considered to be the same.

[0014] One possible design is based on the code disk rotation angle obtained from the first encoder, which includes a first error angle. The first encoder is any one of at least two encoders, and the first error angle is determined based on the following formula (1).

[0015]

[0016] Where θ is the first error angle, and α is the angle between the straight line from the axis of the rotating shaft pointing to the first encoder and the straight line from the axis of the rotating shaft pointing to the center of the code disk.

[0017] One possible design is based on the code disk rotation angle obtained from the second encoder, which includes a second error angle. The second encoder is any encoder other than the first encoder among at least two encoders. The second error angle is determined based on the following formula (2).

[0018]

[0019] Where θ(i) is the second error angle corresponding to the i-th second encoder, i represents the sequence number of the second encoder in the counterclockwise direction based on the first encoder, k represents the number of at least two encoders, and k is an integer greater than or equal to 2.

[0020] In one possible design, the angle measuring device also includes a processor connected to at least two encoders. The processor processes the signals output by the encoders to obtain the code disk rotation angle, and the signals output by the encoders are used to indicate the amount of rotation of the code disk.

[0021] In this design, at least two encoders share a single processor to process signals, thereby simplifying the device structure and reducing costs.

[0022] One possible design is that the processor is specifically used to: determine the code disk rotation angle based on the amount of code disk rotation for any encoder; obtain at least two corresponding code disk rotation angles based on at least two encoders; and calculate the mirror rotation angle based on a portion or all of the at least two code disk rotation angles.

[0023] In this design, considering factors such as encoder malfunction or detection failure, the processor can calculate the rotation angle of the rotating mirror based only on the encoders that are detected normally, thereby ensuring the accuracy and reliability of the measurement of the rotation angle of the rotating mirror.

[0024] One possible design is that the encoder outputs one or more of the following signals: analog signals, pulse signals, digital signals, and modulated signals.

[0025] The design incorporates more signal types, which improves the device's compatibility and allows it to be used in a wider range of scenarios.

[0026] One possible design is that the number of at least two encoders is n times the number of mirrors in the rotating mirror, where n is an integer greater than or equal to 1.

[0027] In this design, the number of encoders is determined by an integer multiple of the number of mirrors of the rotating mirror, so as to use a sufficient number of encoders to improve the measurement error of the rotating mirror rotation angle and improve the accuracy of the rotating mirror rotation angle measurement.

[0028] One possible design is an encoder of one or more of the following types: transmissive photoelectric encoder, reflective photoelectric encoder, magnetic encoder.

[0029] In this design, using different types of encoders to detect the rotation angle of the code disk can improve the compatibility of the angle measurement device, enabling it to be applied in more scenarios.

[0030] One possible design involves at least two encoders located directly below or above the code track on the code disk, with the code track located at the edge of the code disk.

[0031] In this design, the encoder position can be determined based on the structure of the angle measuring device, thereby avoiding structural complexity.

[0032] One possible design is that the code track includes one or more of the following: a grating, a reflective / absorbent area, and alternating north and south magnetic poles.

[0033] In this design, the structure of the code track corresponds to the encoder detection type, which can improve the compatibility of the angle measurement device and enable the angle measurement device to be applied in more scenarios.

[0034] One possible design involves at least two encoders located within the code disk area in the direction of rotation of the shaft.

[0035] In this design, the encoder is located within the code disk area, which avoids the light reflected by the rotating mirror from affecting the code disk, thereby preventing the encoder from being affected by the rotating mirror during operation and ensuring the reliability of the encoder.

[0036] One possible design is that at least two mirrors are tangent to the code disk in the direction of rotation of the shaft.

[0037] In this design, the code disk is tangent to the mirror surface, so that the encoder is located within the code disk area and as far away from the rotating shaft as possible, preventing the rotating shaft from affecting the operation of the encoder and ensuring the reliability of the encoder.

[0038] Secondly, this application also provides a detection device, which includes a transmitting module, a receiving module, a rotating mirror, a motor, and the angle measuring device mentioned in the first aspect above. The rotating mirror and the code disk in the angle measuring device are disposed on the rotating shaft of the motor, and the code disk and the rotating mirror rotate synchronously based on the rotating shaft.

[0039] The transmitting module is used to transmit a probe light signal to the rotating mirror, the rotating mirror is used to reflect the probe light signal, the motor is used to drive the rotating mirror to rotate, and the receiving module is used to receive the echo signal.

[0040] In one possible design, the detection device also includes a point cloud generation module; the point cloud generation module is used to generate a point cloud based on the rotation angle of the rotating mirror and the echo signal, wherein the rotation angle of the rotating mirror is obtained based on an angle measuring device.

[0041] In one possible design, the detection device also includes a lighting module; the lighting module is used to control the frequency of the detection light signal emitted by the transmitting module according to the rotation angle of the rotating mirror, the rotation angle of the rotating mirror being obtained based on an angle measuring device.

[0042] In one possible design, the detection device also includes a control module; the control module is used to control the rotation speed of the motor shaft in order to control the rotation speed of the rotating mirror.

[0043] Thirdly, this application also provides a vehicle that includes the angle measuring device described in the first aspect, or the detection device described in the second aspect.

[0044] In some embodiments, the vehicle includes a new energy vehicle, a hybrid vehicle, a range-extended electric vehicle, or a gasoline vehicle. The design of the angle measuring device in this application can be applied to vehicles with different power types, thereby reducing overall vehicle costs and ensuring the user's driving experience. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of an application scenario provided by an embodiment of this application;

[0046] Figure 2 This is a schematic diagram of a lidar provided in related technologies;

[0047] Figure 3 This is a schematic diagram of the structure of a direct-fire photoelectric encoder provided in an embodiment of this application;

[0048] Figure 4 This is a schematic diagram of the structure of a reflective photoelectric encoder provided in an embodiment of this application;

[0049] Figure 5 A schematic diagram of another reflective photoelectric encoder provided in the embodiments of this application;

[0050] Figure 6 This is a schematic diagram of the structure of a magnetic encoder provided in an embodiment of this application;

[0051] Figure 7 This is a schematic diagram illustrating the location of a point cloud generated by a detection signal based on mirror reflection under an ideal state, as provided in an embodiment of this application.

[0052] Figure 8 A schematic diagram illustrating an eccentric setting between the encoder and the rotating shaft, provided in an embodiment of this application;

[0053] Figure 9 A schematic diagram of the error angle of a single magnetic encoder provided in an embodiment of this application;

[0054] Figure 10 This is a schematic diagram illustrating the location of a point cloud generated by a detection signal based on mirror reflection in a real-world scenario, as provided in an embodiment of this application.

[0055] Figure 11 A schematic diagram of a point cloud provided for an embodiment of this application;

[0056] Figure 12 This is a schematic diagram of the structure of an angle measuring device provided in an embodiment of this application;

[0057] Figure 13 A top view of an angle measuring device provided in an embodiment of this application;

[0058] Figure 14 A top view of yet another angle measuring device provided in the embodiments of this application;

[0059] Figure 15 A schematic diagram of a code disk and five encoders based on the eccentric setting of the rotating shaft provided in an embodiment of this application;

[0060] Figure 16 A schematic diagram of the average error angle of five encoders provided in an embodiment of this application;

[0061] Figure 17 A top view of an angle measuring device based on a 3-mirror rotating mirror provided in an embodiment of this application;

[0062] Figure 18 A top view of an angle measuring device based on a 4-mirror rotating mirror provided in an embodiment of this application;

[0063] Figure 19 A top view of an angle measuring device based on a 6-mirror rotating mirror provided in an embodiment of this application;

[0064] Figure 20 This is a schematic diagram of the structure of a detection device provided in an embodiment of this application.

[0065] Figure label:

[0066] 101-Encoder; 102-Code disk; 103-Rotating shaft; 104-Rotating mirror. Detailed Implementation

[0067] The following describes the possible application scenarios of this application.

[0068] In one possible implementation, the angle measuring device provided in this application can be integrated into a detection device, which can be installed on a vehicle, including but not limited to: vehicles, ships, airplanes, drones, trains, subways, automated guided vehicles (AGVs), or unmanned vehicles. For an example, please refer to [link to example]. Figure 1 This diagram illustrates one possible application scenario of this application. Taking the detection device installed on the front bumper of a vehicle as an example, this device can serve as an information source for path planning, assisting the driver in achieving or automatically achieving safe driving. It is understood that the detection device can also be installed in other locations on the vehicle, such as around the headlights, rearview mirrors, near the doors, the rear bumper, behind the windshield, or on the roof, to capture information about the vehicle's surrounding environment. When the detection device is installed behind the windshield, the requirement for no stone collision is lower, it does not affect the vehicle's appearance, and the windshield itself has built-in window heating and defogging functions as well as wiper cleaning functions.

[0069] It should be understood that the above application scenarios are merely examples, and the detection device provided in this application can also be applied to other possible scenarios, and is not limited to those exemplified above. For example, the detection device can also be installed in a roadside unit (RSU) as a roadside traffic detection device to realize intelligent vehicle-road cooperative communication. For example, the detection device can also be installed in the cabin of a vehicle as a liveness detection device to detect and alert the user to children or pets left behind in the cabin. Furthermore, the detection device can also be applied to terminal devices or components of terminal devices, such as smartphones, smart home devices, smart manufacturing equipment, medical devices, industrial equipment, and robots. These will not be listed exhaustively here.

[0070] It should be noted that the application scenarios described in this application are for the purpose of more clearly illustrating the technical solutions of this application, and do not constitute a limitation on the technical solutions provided in this application.

[0071] In addition, the above-mentioned application scenarios can be applied to fields such as autonomous driving, assisted driving, intelligent driving, autonomous driving, connected vehicles, optical communication, security monitoring, biomedicine, surveying and mapping (such as 3D mapping and remote sensing mapping), meteorological research, biomass and vegetation research, air quality monitoring, and aviation and aerospace applications.

[0072] The aforementioned detection devices may include, but are not limited to, LiDAR (light detection and ranging). LiDAR, as a commonly used detection technology, is widely applied in various fields such as autonomous driving, driver assistance, and object recognition. Before introducing the specific solutions provided in this application, the relevant content of LiDAR will be introduced below. It should be noted that this content is for the convenience of those skilled in the art and does not constitute a limitation on the scope of protection claimed in this application.

[0073] A lidar (Light Detection and Ranging) system is a radar system that uses laser beams to detect the position, velocity, and other characteristics of a target. Its working principle involves emitting a detection signal (laser beam, or detection light) towards the target, and then comparing the received signal reflected back from the target (echo signal) with the detection signal to obtain relevant target information (such as target range, azimuth, altitude, velocity, attitude, and shape). It typically consists of a laser transmitter, an optical receiver, a turntable, and an information processing system. The turntable includes a rotating mirror and a motor, with the motor driving the mirror to rotate.

[0074] For further details, please refer to Figure 2 , Figure 2 This is a schematic diagram of a lidar system provided in related technologies. The lidar includes a laser transmitter, a rotating mirror, a reflector, and an optical receiver. The laser transmitter emits a detection signal, which is incident on the surface of the rotating mirror via the reflector, and then reflected back off the mirror. The reflector and laser transmitter are fixed, while the rotating mirror rotates on a motor. As the rotating mirror rotates, the angle of incidence of the detection signal on the mirror changes, and the angle of the detection signal reflected from the mirror also changes accordingly. Over time, this forms a grating, thus achieving laser scanning. After the detection signal illuminates the target, it is reflected back from the target as an echo signal. The optical receiver receives the echo signal and generates a point cloud (or laser point cloud) based on the echo signal, the detection signal, and the rotation angle of the rotating mirror, thereby locating the target in three-dimensional space. It should be noted that the method for generating the point cloud is well-known to those skilled in the art, and this application does not limit its scope.

[0075] Currently, the rotation angle of a rotating mirror is generally obtained by an encoder detecting the code disk. These encoders include, but are not limited to, photoelectric encoders, magnetic encoders, inductive encoders, and capacitive encoders. For ease of description, this application uses photoelectric encoders and magnetic encoders as examples, but is not limiting in this regard.

[0076] Please see Figure 3 , Figure 3This is a schematic diagram of a direct-fire photoelectric encoder provided in an embodiment of this application. The direct-fire photoelectric encoder includes a transmitter and a receiver. The code disk detected by the direct-fire photoelectric encoder is mounted on the motor shaft, and the code disk rotates synchronously with the shaft; the code disk is also called the rotor. The code track of the code disk includes a uniformly distributed grating (or light-transmitting area / light-transmitting aperture). The transmitter is used to send a light beam (as shown by the dotted line in the figure), and the receiver is used to receive the light beam passing through the code track grating and locate the position of the code disk based on the received light beam, thereby detecting the amount of rotation of the code disk. The transmitter and receiver are fixedly mounted; the transmitter and receiver are also called the stator.

[0077] Please see Figure 4 , Figure 4 This is a schematic diagram of a reflective photoelectric encoder provided in an embodiment of this application. The reflective photoelectric encoder includes a transmitter and a receiver. The code disk detected by the reflective photoelectric encoder is mounted on the motor shaft, and the code disk rotates synchronously with the shaft; the code disk is also called the rotor. The code track of the code disk includes uniformly distributed light-absorbing areas and reflective areas. The transmitter is used to send a light beam (as shown by the dotted line in the figure), and the receiver is used to receive the light beam reflected from the reflective areas of the code track (the light-absorbing areas absorb the light beam sent by the transmitter, so the receiver cannot receive the light beam in the light-absorbing areas). The receiver locates the position of the code disk based on the received light beam, thereby detecting the amount of rotation of the code disk. The transmitter and receiver are fixedly mounted; the transmitter and receiver are also called the stator.

[0078] Please see Figure 5 , Figure 5 This is a schematic diagram of another reflective photoelectric encoder provided in an embodiment of this application. The reflective photoelectric encoder is a transceiver used to implement the above-described... Figure 4 Functions of the transmitter and receiver. Figure 5 The function of the reflective photoelectric encoder shown is the same as Figure 4 The reflective photoelectric encoder shown has the same function, and will not be described in detail here.

[0079] Please see Figure 6 , Figure 6 This is a schematic diagram of a magnetic encoder provided in an embodiment of this application. The magnetic encoder is a chip (or magnetic induction chip). The code disk detected by the magnetic encoder is mounted on the motor shaft, and the code disk rotates synchronously with the shaft; the code disk is also called the rotor. The code track of the code disk includes alternating north (S) and south (N) magnetic poles (as shown in the diagram, the shaded area represents the N pole, and the unshaded area represents the S pole); this code disk can also be called a magnetic pole code disk. The magnetic induction chip is used to locate the position of the code disk based on the direction and strength of the magnetic field, thereby detecting the amount of rotation of the code disk. The magnetic induction chip is fixedly mounted; the magnetic induction chip is also called the stator.

[0080] It should be noted that the above Figure-3 Figure 6 The working principle of the encoder is a well-known technology to those skilled in the art, and this application will not make any special explanation here.

[0081] In an ideal state, for any two mirrors of a rotating mirror, from the start of reflecting the detection signal to the end of reflecting the detection signal... Figure 2 The point cloud locations generated by the optical receivers shown are the same. Please refer to [link / reference]. Figure 7 , Figure 7 This diagram illustrates the position of a point cloud generated by a detection signal based on a rotating mirror reflection under ideal conditions, as provided in an embodiment of this application. The horizontal axis represents the position of the point cloud, and the vertical axis represents the point cloud generated by each mirror surface from the start to the end of the detection signal reflection. The diagram uses four mirror surfaces, with each surface generating m points, where m is a positive integer greater than or equal to 1. It can be seen that the point cloud positions generated by any two mirror surfaces are identical.

[0082] However, in reality, assembly errors exist between the encoder and the motor shaft. For example, the encoder may be misaligned, eccentric (or have poor concentricity between the encoder and the shaft), or exhibit non-linearity. Please refer to [link / reference]. Figure 8 , Figure 8 This is a schematic diagram illustrating an eccentric arrangement of the code disk and the rotating shaft, provided in an embodiment of this application. The dashed circular lines represent the ideal position of the code disk, i.e., the code disk and the rotating shaft are concentric; the solid circular lines represent the actual position of the code disk, i.e., there is concentricity between the code disk and the rotating shaft; and the solid rectangular lines represent the encoder position. It should be noted that... Figure 8 Taking a code disk as a magnetic pole code disk and an encoder as a magnetic induction chip as an example, this application does not impose any restrictions.

[0083] Furthermore, o represents the center of the ideal position of the code disk (i.e., the axis of the rotating shaft), e represents the center of the actual position of the code disk (based on the straight line from the axis of the rotating shaft o to the center of the actual position of the code disk e, which corresponds to the x-axis in the diagram, and e also represents the eccentricity between the center of the actual position of the code disk and the axis of the rotating shaft), R represents the distance between the encoder and the center of the actual position of the code disk, α represents the angle between the straight line from the axis of the rotating shaft o to the encoder and the x-axis (for ease of description, it is simply referred to as the ideal angle below), β represents the angle between the straight line from the center of the actual position of the code disk e to the encoder and the x-axis (for ease of description, it is simply referred to as the actual angle below). According to the exterior angle theorem of a triangle (i.e., an exterior angle of a triangle is equal to the sum of its two non-adjacent interior angles), in the triangle formed by the encoder position, the axis of the rotating shaft o, and the center of the code disk e, the exterior angle β is the sum of the interior angles θ and α, that is, the relationship between α and β is: α = β - θ, so θ represents the error angle (theta) included in β. Based on the Law of Sines (that is, in a triangle, the ratio of the sine of each side to the sine of its opposite angle is equal), we know that in the above triangle, Based on this, the above relationship is shifted, and the error angle can be obtained by the inverse trigonometric formula, i.e., the following formula (1).

[0084]

[0085] Furthermore, taking R = 5cm, eccentricity e = 0.5cm, and the motor rotating one revolution (from -π to +π) as an example, substituting into the above formula (1), we can obtain the following: Figure 9 The error distribution is shown. Figure 9 This diagram illustrates the error angle of a single magnetic encoder as provided in an embodiment of this application. The horizontal axis represents the motor rotation period (-π to +π), and the vertical axis represents the error angle within that period, with the unit of error angle being radians (rad). It can be seen that the error angle range based on a single magnetic encoder is ±0.1 rad.

[0086] Since the aforementioned encoder rotation angle is used as the mirror rotation angle, the error angle of the encoder rotation angle is equivalent to the mirror rotation error angle. Therefore, because the mirror rotation angle includes the error angle, the point cloud positions generated based on any two mirror surfaces will be different. Please refer to [link / reference]. Figure 10 , Figure 10 This diagram illustrates the position of a point cloud generated by a detection signal based on mirror reflection in a practical state, as provided in an embodiment of this application. The horizontal axis represents the position of the point cloud, and the vertical axis represents the point cloud generated by each mirror from the start to the end of the detection signal reflection. The diagram uses four mirrors, with each mirror generating m points, where m is a positive integer greater than or equal to 1. It can be seen that the positions of the point clouds generated by any two mirrors are different.

[0087] based on Figure 10 , Figure 11 This is a schematic diagram of a point cloud provided as an embodiment of this application. For example... Figure 11 As shown, the horizontal axis represents the mirror rotation angle (i.e., the angle of the detection signal on the mirror rotation plane, referred to here as the horizontal angle for ease of distinction), and the vertical axis represents the vertical angle of the detection signal (i.e., the angle between the detection signal and the perpendicular line of the rotating mirror). In the diagram, shaded points represent the point cloud generated by one mirror, and unshaded points represent the point cloud generated by the other mirror. It can be seen that because the point clouds generated by the two mirrors are at different positions, the generated point clouds differ significantly (or exhibit considerable jitter), leading to a large error and low accuracy in the final generated point cloud.

[0088] Based on the above description, assembly errors (eccentricity, skewness, nonlinearity, etc.) between the encoder and the motor shaft directly affect the accuracy of the rotating mirror's rotation angle measurement. As application scenarios become increasingly complex, the requirements for the angle accuracy of LiDAR are becoming increasingly stringent. If the measured rotating mirror rotation angle accuracy is insufficient, it will cause jitter in the point cloud image, leading to misidentification of targets and impacting the user experience of the LiDAR. Therefore, improving the accuracy of rotating mirror rotation angle measurement is a pressing technical problem that needs to be solved.

[0089] In view of this, this application provides an angle measuring device, which aims to reduce the measurement error of the rotating mirror rotation angle and improve the accuracy of the rotating mirror rotation angle measurement by setting at least two encoders to detect the rotation angle of the code disk and determining the rotation angle of the rotating mirror based on the rotation angle of the code disk corresponding to at least two encoders.

[0090] To make the objectives, technical solutions, and advantages of this application clearer, the application will now be described in further detail with reference to the accompanying drawings.

[0091] In the following embodiments, the terminology used is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” and “this” are intended to also include expressions such as “one or more,” unless the context clearly indicates otherwise. It should also be understood that in the embodiments of this application, “one or more” means one, two, or more; “and / or” describes the relationship between related objects, indicating that three relationships may exist; for example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character “ / ” generally indicates that the preceding and following related objects are in an “or” relationship.

[0092] In the description of this specification, references to "one embodiment" or "some embodiments," etc., mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification, do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0093] The "multiple" mentioned in the embodiments of this application refers to two or more. It should be noted that in the description of the embodiments of this application, terms such as "first" and "second" are used only for the purpose of distinguishing descriptions and should not be construed as indicating or implying relative importance, nor should they be construed as indicating or implying order.

[0094] Please see Figure 12 , Figure 12 This is a schematic diagram of an angle measuring device provided in an embodiment of this application. The angle measuring device includes at least two encoders 101 and a code disk 102. The code disk 102 is mounted on a rotating shaft 103, and a rotating mirror 104 is mounted on the rotating shaft 103. The code disk 102 and the rotating mirror 104 rotate synchronously based on the rotating shaft 103. It should be noted that... Figure 12 Using encoder 101 as an example Figure 5 The reflective photoelectric encoder shown takes the code track of code disk 102 as an example, which includes uniformly distributed light-absorbing areas and reflective areas. This application does not limit this. Figure 12 The example uses five encoders 101, but this application does not limit the number of encoders 101.

[0095] Optionally, the encoder 101 may be of one or more of the following types: transmissive photoelectric encoder (e.g., ... Figure 3 As shown), reflective photoelectric encoders (such as...) Figure 4 or Figure 5 As shown), magnetic encoder (such as Figure 6 As shown), this application does not limit it. Based on this, the code track of code disk 102 (as shown) Figure 13 or Figure 14 The shaded area shown includes one or more of the following: a grating, a reflective / absorbing area, and alternating north and south magnetic poles, which are not limited herein. It is understood that the code track of the code disk 102 corresponds to the type of the encoder 101. For example, a transmissive photoelectric encoder corresponds to a code track including a grating, a reflective photoelectric encoder corresponds to a code track including a reflective / absorbing area, and a magnetic encoder corresponds to a code track including alternating north and south magnetic poles. Optionally, the encoder type can also be an inductive encoder, a capacitive encoder, etc., which are not limited herein. Therefore, this application can be applied to different types of encoders, thereby improving the compatibility of the angle measuring device and enabling it to be used in more scenarios.

[0096] refer to Figure 12 The rotating mirror 104 can be understood as a polygonal prism (shown as a pentagonal prism in the figure), with a reflective layer (i.e., a mirror surface) coated on its sides. In this embodiment, the rotating mirror 104 includes at least two mirror surfaces (e.g., Figure 12 Each side of the pentagon corresponds to a mirror.

[0097] Optionally, at least two mirrors of the rotating mirror 104 may have the same included angle between any two adjacent mirrors, in order to facilitate the detection of the angle of the probe light reflected from any two mirrors.

[0098] Optionally, at least two of the mirror surfaces of the rotating mirror 104 are identical; in other words, the rotating mirror 104 is a regular polygonal prism, meaning its top view is a regular polygon. Based on Figure 12 , Figure 13 This is a top view of an angle measuring device provided in an embodiment of this application. Figure 13 As shown, the top view of the rotating mirror 104 is a regular pentagon.

[0099] Considering that the more mirrors the rotating mirror 104 has, the greater the impact of the assembly error between the code disk 102 and the rotating shaft 103 on the accuracy of the rotating mirror rotation angle measurement, this application limits the number of encoders 101 to be greater than or equal to the number of mirrors of the rotating mirror 104, so as to improve the accuracy of the rotating mirror rotation angle measurement by setting a larger number of encoders 101. Figure 12 or Figure 13 As shown, the number of encoders 101 is equal to the number of mirrors of rotating mirror 104.

[0100] Optionally, the number of encoders 101 is n times the number of mirrors in the rotating mirror 104, where n is an integer greater than or equal to 1. For example... Figure 12 or Figure 13 The number of encoders 101 shown is twice the number of mirrors in the rotating mirror 104. See also... Figure 14 , Figure 14 This is a top view of yet another angle measuring device provided in an embodiment of this application. Figure 14 The number of encoders 101 shown is twice the number of mirrors in the rotating mirror 104. That is, the number of encoders 101 is determined to be an integer multiple of the number of mirrors in the 104 rotating mirrors, so as to use a sufficient number of encoders 101 to improve the effect of reducing the measurement error of the rotating mirror rotation angle and improve the accuracy of the rotating mirror rotation angle measurement.

[0101] Optionally, the number of encoders 101 may not be a multiple of the number of mirrors in the rotating mirror 104, and this application does not impose any restrictions on this.

[0102] Optionally, at least two encoders 101 are evenly distributed based on the rotating shaft 103. For example... Figure 13 or Figure 14 As shown, at least two encoders 101 are evenly distributed along the rotation direction of the rotating shaft 103. Alternatively, with the axis of the rotating shaft 103 as a circle, any two adjacent encoders 101 have the same included angle. This ensures the balance of the rotation angle detected by the at least two encoders 101, thereby better reducing the measurement error of the rotating mirror's rotation angle.

[0103] Optionally, encoder 101 is located on the code track of code disk 102 (e.g., Figure 13 or Figure 14 The encoder track is located directly below or above the shaded area shown, at the edge of the code disk 102. This allows the position of the encoder 101 to be determined based on the structure of the angle measuring device, thereby reducing the structural complexity of the angle measuring device.

[0104] Optionally, in the rotational direction (i.e., horizontal direction) of the shaft 103, the encoder 101 is located within the area of ​​the code disk 102. For example... Figure 13 As shown, the edge of each encoder 101 does not exceed the outer edge of the code disk 102, thereby preventing the encoder 101 from receiving light reflected by the rotating mirror 104, thus preventing the encoder 101 from being affected by the rotating mirror 104 during operation and ensuring the reliability of the encoder 101.

[0105] Optionally, in the rotation direction (i.e., horizontal direction) of the rotating shaft 103, at least two mirror surfaces of the rotating mirror 104 are tangent to the code disk 102. For example, in the horizontal direction, the code disk 102 is internally tangent to at least two mirror surfaces of the rotating mirror 104 (e.g., ...). Figure 13 or Figure 14 The code disk 102 shown may be tangent to five mirror surfaces of the rotating mirror 104, or tangent to at least two mirror surfaces of the rotating mirror 104; this application does not limit this. By limiting the tangency of the code disk 102 to the mirror surfaces, the encoder 101 can be located within the area of ​​the code disk 102 while being as far away as possible from the rotating shaft 103, preventing the rotating shaft from affecting the operation of the encoder. For example, if the encoder 101 is a magnetic encoder, the rotation of the rotating shaft 103 may generate a magnetic field. By keeping the encoder 101 as far away from the rotating shaft 103 as possible, the reliability of the encoder 101 is ensured.

[0106] In the above structure, encoder 101 is used to detect the rotation angle of the code disk. Specifically, encoder 101 detects the rotation amount of code disk 102 and outputs a signal. It should be noted that this signal is used to indicate the rotation amount of code disk 102. Figure 3 Taking the transmissive photoelectric encoder shown as an example, encoder 101 can detect light signals based on the light-transmitting area of ​​code disk 102, and therefore outputs a high level. Encoder 101 cannot detect light signals based on the opaque area of ​​code disk 102, and therefore outputs a low level. Therefore, the signal output by encoder 101 can be a square waveform pulse signal.

[0107] Optionally, based on the encoder type described above, the encoder output signal includes one or more of the following: analog signal, pulse signal, digital signal, and modulated signal. It should be noted that the signal type output by the encoder in this application corresponds to the encoder type, but this application does not impose any limitations on this.

[0108] In this embodiment, the angle measuring device further includes a processor (not shown in the figure). Optionally, the processor is connected to at least two encoders 101 and is used to process the signals output by the encoders 101. This means that at least two encoders 101 share a single processor to process the signals, thereby simplifying the device structure and reducing costs.

[0109] Furthermore, the processor is specifically used to: process the signal output by any encoder 101 to obtain the rotation amount of the code disk, and then determine the corresponding code disk rotation angle based on the rotation amount of the code disk. For example, if the signal output by the encoder 101 is an ABZ pulse signal, the processor calculates the number of pulses based on the ABZ pulse signal to obtain the rotation amount of the code disk, and then obtains the corresponding code disk rotation angle based on the radian corresponding to each pulse. It should be noted that determining the code disk rotation angle based on the signal output by the encoder 101 is common knowledge to those skilled in the art, and this application does not limit or elaborate on it here. Based on this, for at least two encoders, at least two corresponding code disk rotation angles can be obtained (i.e., at least two code disk rotation angles are obtained based on at least two encoders 101), and then the rotation angle of the rotating mirror is calculated based on the at least two code disk rotation angles (i.e., at least two code disk rotation angles are used to determine the rotation angle of the rotating mirror).

[0110] Optionally, considering that at least two encoders may be malfunctioning or have failed detection, the processor can calculate the mirror rotation angle based only on the code disk rotation angles of the successfully detected encoders. That is, the processor calculates the mirror rotation angle based on a portion of the at least two code disk rotation angles. If at least two encoders are detected normally, the processor can calculate the mirror rotation angle based on all of the at least two code disk rotation angles.

[0111] In this embodiment of the application, the rotation angle of the rotating mirror is calculated using all the rotation angles of the code disks out of at least two code disk rotation angles as an example. Specifically, it may include the following methods.

[0112] Method 1: The rotation angle of the rotating mirror is the average of the rotation angles of at least two code disks.

[0113] In this first method, the processor calculates the average of at least two code disk rotation angles to obtain the mirror rotation angle. For example, Figure 12 The five encoders 101 shown all output ABZ pulse signals. The processor counts the ABZ pulse signals output by each encoder and, based on the radian corresponding to each pulse, obtains the code disk rotation angles corresponding to the five encoders 101, namely A1, A2, A3, A4, and A5. Then, the average value is calculated based on these five code disk rotation angles. The average value As the rotation angle of the rotating mirror, this rotation angle is used as a parameter for subsequent calculation of the point cloud position.

[0114] Method 2: The rotation angle of the rotating mirror is the weighted average of the rotation angles of at least two encoders; wherein, the weights of at least two encoders are positively correlated with the angle detection accuracy.

[0115] In Method 2, the angle detection accuracy of each encoder 101 can be obtained through pre-testing, and this application does not impose any restrictions on this. Referring to Method 1 above, the processor calculates a weighted average value A` = μ1*A1 + μ2*A2 + μ3*A3 + μ4*A4 + μ5*A5 based on the rotation angles of the five code disks (A1, A2, A3, A4, A5), where μ1 + μ2 + μ3 + μ4 + μ5 = 1. This weighted average value A` is used as the rotation angle of the rotating mirror, which is a parameter for subsequently calculating the point cloud position.

[0116] In summary, at least two encoders 101 measure the code disk 102. In other words, each of the at least two encoders 101 measures the same code disk 102, thus obtaining a corresponding code disk rotation angle for each encoder 101, resulting in at least two code disk rotation angles (referred to as actual code disk rotation angles for clarity). It is understandable that, generally, due to assembly errors between the code disk 102 and the rotating shaft 103, the actual code disk rotation angles corresponding to any two encoders 101 are different. In other words, the actual code disk rotation angle corresponding to each encoder 101 has errors and is not accurate (or ideal). Compared to the ideal code disk rotation angle (referred to as the ideal code disk rotation angle), these actual code disk rotation angles are greater than or less than the ideal code disk rotation angle. In other words, the error angles included in these actual code disk rotation angles are either positive or negative compared to the ideal code disk rotation angle. Therefore, the measurement error of the actual code disk rotation angle is neutralized by averaging or weighted averaging, thereby reducing the measurement error of the rotating mirror rotation angle and improving the accuracy of the rotating mirror rotation angle measurement.

[0117] Taking method one above as an example, refer to the above... Figure 8 content, Figure 15 This is a schematic diagram illustrating a code disk and five encoders arranged based on the eccentricity of the rotating shaft, as provided in an embodiment of this application. Figure 15As shown, the dashed circular line represents the ideal position of the code disk, i.e., the code disk and the shaft are concentric; the solid circular line represents the actual position of the code disk, i.e., there is concentricity between the code disk and the shaft; the solid rectangular line represents the encoder position. o represents the center of the ideal position of the code disk (i.e., the axis of the shaft), e represents the center of the actual position of the code disk (based on the straight line from the axis of the shaft o to the center of the actual position e of the code disk, this line corresponds to the x-axis in the diagram, e is the eccentricity between the center of the actual position of the code disk and the axis of the shaft, e is greater than 0), and R represents the distance between the encoder and the center of the actual position of the code disk. Since the encoder is based on the code disk, the distance between any one of the two encoders and the center of the code disk is considered to be the same, which is R.

[0118] by Figure 8 Taking the first encoder as an example, the first encoder can be any one of at least two encoders. The first error angle included in the code disk rotation angle corresponding to the first encoder is determined based on the following formula (1).

[0119]

[0120] Where θ is the first error angle, α is the angle between the straight line from the axis o of the rotating shaft pointing to the first encoder and the straight line from the axis o of the rotating shaft pointing to the center of the actual position of the code disk (i.e., the x-axis) (corresponding to the ideal angle mentioned above), and β represents the angle between the straight line from the center e of the actual position of the code disk pointing to the first encoder and the x-axis (corresponding to the actual angle mentioned above). For a detailed description, please refer to the above. Figure 8 The contents of this application will not be elaborated here.

[0121] Since the five encoders 101 are evenly distributed, the second error angle included in the code disk rotation angle corresponding to the second encoder can be determined based on the following formula (2). The second encoder is any encoder other than the first encoder among at least two encoders.

[0122]

[0123] Where θ(i) is the second error angle corresponding to the i-th second encoder, i represents the sequence number of the second encoder in the counterclockwise direction based on the first encoder, and k represents the number of at least two encoders, where k is an integer greater than or equal to 2. For example, k is 5, and the angular interval between any two adjacent encoders 101 is 2π / 5. Therefore, the error angles corresponding to the 1st, 2nd, 3rd, and 4th second encoders are respectively:

[0124] Based on the error angles corresponding to the above 5 encoders, the average error angle can be calculated as follows:

[0125] Furthermore, taking R = 5cm, eccentricity e = 0.5cm, and the motor rotation time from -π to +π per revolution as an example, substituting the above information, we can obtain the following: Figure 16 The error distribution is shown. Figure 16 This is a schematic diagram illustrating the average error angle of five encoders provided in an embodiment of this application. The horizontal axis represents the motor rotation period (-π to +π). Figure 16 The diagram shows five cycles, with the vertical axis representing the error angle within each cycle, in radians (rad). It can be seen that the average error angle range of the five encoders is ±5*1e-8 rad (i.e., 5×10⁻⁸ rad). -8 (rad). Compared to Figure 9 The error angle range of a single encoder (±0.1 rad) and the average error angle range of the five encoders (±5 × 10⁻⁶) are shown. -8 The error angle (rad) is much smaller than the range of the error angle of a single encoder (±0.1rad).

[0126] Based on the above Figure 10 and Figure 11 The relevant content, by reducing the measurement error of the rotating mirror's rotation angle and improving the accuracy of the rotating mirror's rotation angle measurement, can reduce the jitter problem of the subsequently generated point cloud and improve the motor control accuracy. For a detailed description, please refer to the above content, which will not be repeated here.

[0127] Based on the above description Figure 17 This is a top view of an angle measuring device based on a three-mirror rotating mirror, provided as an embodiment of this application. Figure 17 As shown, the top view of the rotating mirror 104 is a regular triangle. Figure 17 In Figure a, the number of encoders 101 is twice the number of mirrors in rotating mirror 104. Figure 17 In Figure b, the number of encoders 101 is twice the number of mirrors of rotating mirror 104.

[0128] Figure 18 This is a top view of an angle measuring device based on a four-mirror rotating mirror, provided as an embodiment of this application. Figure 18 As shown, the top view of the rotating mirror 104 is a regular quadrilateral. Figure 18 In Figure a, the number of encoders 101 is twice the number of mirrors in rotating mirror 104. Figure 18 In Figure b, the number of encoders 101 is twice the number of mirrors of rotating mirror 104.

[0129] Figure 19 This is a top view of an angle measuring device based on a 6-mirror rotating mirror, provided as an embodiment of this application. Figure 19 As shown, the top view of the rotating mirror 104 is a regular hexagon. Figure 19 In Figure a, the number of encoders 101 is twice the number of mirrors in rotating mirror 104. Figure 19 In Figure b, the number of encoders 101 is twice the number of mirrors of rotating mirror 104.

[0130] It should be noted that, Figures 17-19 The solution is the same as the above. Figure 12 The scheme shown is similar, the difference being the number of mirrors in the rotating mirror 104 and the number of encoders 101. For details, please refer to the above content, and this application will not repeat them here.

[0131] Based on the above description, embodiments of this application also provide a detection device. Please refer to... Figure 20 , Figure 20 This is a schematic diagram of a detection device provided in an embodiment of this application. The device includes a transmitting module, a receiving module, a rotating mirror, a motor, and an angle measuring device as described in the above embodiment. The rotating shaft of the angle measuring device is the rotating shaft of the motor, and the rotating mirror and the code disk in the angle measuring device are mounted on the rotating shaft of the motor, with the code disk and the rotating mirror rotating synchronously based on the rotating shaft.

[0132] The transmitting module is used to transmit a probe light signal to the rotating mirror, the rotating mirror is used to reflect the probe light signal, the motor is used to drive the rotating mirror to rotate, and the receiving module is used to receive the echo signal.

[0133] Optionally, the detection device also includes a point cloud generation module; the point cloud generation module is used to generate a point cloud based on the rotation angle of the rotating mirror and the echo signal, wherein the rotation angle of the rotating mirror is obtained based on the angle measuring device.

[0134] Optionally, the detection device also includes a lighting module; the lighting module is used to control the frequency of the detection light signal emitted by the transmitting module according to the rotation angle of the rotating mirror, the rotation angle of the rotating mirror being obtained based on the angle measuring device.

[0135] Optionally, the detection device may also include a control module; the control module is used to control the rotation speed of the motor shaft in order to control the rotation speed of the rotating mirror.

[0136] Figure 20 The function of the angle measuring device shown is the same as described above, and will not be repeated here.

[0137] Based on the above, this application may also provide a terminal device. This terminal device includes the angle measuring device described above, or includes the detection device described above. Related technical solutions are described above and will not be repeated here.

[0138] For example, the terminal device can be a vehicle, such as a car, truck, motorcycle, bus, recreational vehicle, amusement park vehicle, construction equipment, tram, toy car, golf cart, train, etc., and this application does not impose any particular limitation. Furthermore, the vehicle can be a new energy vehicle, including electric vehicles, such as two-wheel drive electric vehicles or four-wheel drive electric vehicles, or a gasoline-powered vehicle, and this application does not impose any limitation in either case. In other words, the design of the angle measuring device in this application can be applied to vehicles with different power types to reduce overall vehicle costs and ensure a better user experience.

[0139] Alternatively, the terminal equipment can also be other means of transportation, such as airplanes, ships, trains, high-speed trains, etc.

[0140] Alternatively, the terminal device can also be a non-transportation vehicle, such as a smart home robot, an industrial robot, or an autonomous following wheelchair.

[0141] Alternatively, the terminal device can also be an electronic device connected to the vehicle or non-vehicle to be controlled. Examples of such electronic devices include user equipment, roadside units, etc.

[0142] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An angle measuring device, characterized in that, It includes at least two encoders and a code disk, the code disk is disposed on a rotating shaft, a rotating mirror is disposed on the rotating shaft, and the code disk and the rotating mirror rotate synchronously based on the rotating shaft, and the at least two encoders are evenly distributed based on the rotating shaft; The rotating mirror includes at least two mirror surfaces, wherein any adjacent mirror surfaces have the same included angle, and the number of the at least two encoders is greater than or equal to the number of mirror surfaces of the rotating mirror.

2. The angle measuring device as described in claim 1, characterized in that, The rotation angle of the rotating mirror is the average of the rotation angles of at least two code disks, or the rotation angle of the rotating mirror is the weighted average of the rotation angles of the at least two code disks; wherein the weights corresponding to the at least two encoders are positively correlated with the angle detection accuracy, and the rotation angles of the at least two code disks are obtained based on the at least two encoders.

3. The angle measuring device as described in claim 1 or 2, characterized in that, The eccentricity between the center of the code disk and the axis of the rotating shaft is e, where e is greater than 0, and the distance between any one of the at least two encoders and the center of the code disk is R, where R is greater than 0.

4. The angle measuring device as described in claim 3, characterized in that, The code disk rotation angle obtained based on the first encoder includes a first error angle, wherein the first encoder is any one of the at least two encoders, and the first error angle is determined based on the following formula (1); Wherein, θ is the first error angle, and α is the angle between the straight line from the axis of the rotating shaft pointing to the first encoder and the straight line from the axis of the rotating shaft pointing to the center of the code disk.

5. The angle measuring device as described in claim 4, characterized in that, The code disk rotation angle obtained based on the second encoder includes a second error angle, wherein the second encoder is any encoder other than the first encoder among the at least two encoders, and the second error angle is determined based on the following formula (2); Where θ(i) is the second error angle corresponding to the i-th second encoder, i represents the sequence number of the second encoder in the counterclockwise direction based on the first encoder, k represents the number of the at least two encoders, and k is an integer greater than or equal to 2.

6. The angle measuring device as described in claim 2, characterized in that, The angle measuring device further includes a processor connected to the at least two encoders. The processor processes the signals output by the encoders to obtain the rotation angle of the code disk. The signals output by the encoders are used to indicate the amount of rotation of the code disk.

7. The angle measuring device as described in claim 6, characterized in that, The processor is specifically used for: For any encoder, the rotation angle of the code disk is determined based on the amount of rotation of the code disk; Based on the at least two encoders, at least two corresponding code disk rotation angles are obtained; The rotation angle of the rotating mirror is calculated based on a portion or all of the rotation angles of the at least two code disks.

8. The angle measuring device as described in claim 6, characterized in that, The encoder output signal includes one or more of the following: analog signal, pulse signal, digital signal, and modulated signal.

9. The angle measuring device according to any one of claims 1-8, characterized in that, The number of the at least two encoders is n times the number of mirrors of the rotating mirror, where n is an integer greater than or equal to 1.

10. The angle measuring device according to any one of claims 1-9, characterized in that, The encoder type is one or more of the following: transmissive photoelectric encoder, reflective photoelectric encoder, magnetic encoder.

11. The angle measuring device according to any one of claims 1-10, characterized in that, The at least two encoders are located directly below or above the code track of the code disk, and the code track is located at the edge of the code disk.

12. The angle measuring device as described in claim 11, characterized in that, The code track includes one or more of the following: a grating, a reflective / absorbent region, and alternating north and south magnetic poles.

13. The angle measuring device according to any one of claims 1-12, characterized in that, In the direction of rotation of the shaft, the at least two encoders are located within the code disk area.

14. The angle measuring device according to any one of claims 1-13, characterized in that, In the direction of rotation of the shaft, the at least two mirror surfaces are tangent to the code disk.

15. A detection device, characterized in that, The device includes a transmitting module, a receiving module, a rotating mirror, a motor, and an angle measuring device as described in any one of claims 1 to 11, wherein the rotating mirror and the code disk in the angle measuring device are disposed on the rotating shaft of the motor, and the code disk and the rotating mirror rotate synchronously based on the rotating shaft; The transmitting module is used to transmit a detection light signal to the rotating mirror, the rotating mirror is used to reflect the detection light signal, the motor is used to drive the rotating mirror to rotate, and the receiving module is used to receive the echo signal.

16. A vehicle, characterized in that, It includes the angle measuring device as described in any one of claims 1 to 14, or the detection device as described in claim 15.

Images