Method for determining maximum detection field angle and detection distance of mechanical scanning laser radar

Abstract

A method for determining the maximum detection field angle and the detection distance of a mechanical scanning laser radar belongs to the technical field of radars, and comprises the following steps: determining necessary interior orientation elements and design parameters thereof, and establishing a laser beam transmission link model of the mechanical scanning laser radar; calculating the shortest distance between the optical axis of the emitted light beam and the edge of the scanning mirror surface as well as the edge of the optical window glass, and determining a laser emission and echo boundary model constrained by the integrity of the emitted laser spot and the receiving field angle; and establishing and designing a laser radar detection view field model constrained by geometric parameters and a detection distance model constrained by the rotating speed of a scanning motor. According to the method for determining the maximum detection field angle and the detection distance of the mechanical scanning laser radar, a laser beam transmission link model and a geometric constraint relationship are established based on laser radar design model parameters, so that the maximum detection field angle and the detection distance which can be reached by the laser radar are determined; the problem that the structural design of the mechanical scanning laser radar is not matched with the detection target range is solved.

Description

Technical Field

[0001] The invention relates to a method for determining a maximum detection field angle and a detection distance of a mechanical scanning laser radar, and belongs to the technical field of radars. Background Art

[0002] LiDAR is a radar system that emits laser beams to detect the position, speed and other characteristic quantities of a target. In recent years, it has played an increasingly important role in basic surveying and mapping, unmanned driving, digital cities and other fields. LiDAR uses distance measurement methods such as TOF (time of flight) to obtain the distance and direction of the target relative to the LiDAR, and realizes the three-dimensional coordinate measurement of the target. Then, IMU (inertial measurement unit) and GNSS (global navigation satellite system) are used to obtain the geographic coordinates of the scanned target through information fusion and coordinate conversion.

[0003] Mechanical scanning LiDAR changes the scanning angle of the emitted light beam by rotating or swinging the scanning mechanism to achieve the detection field of view designed by the LiDAR. Due to the spatial constraints such as the design parameters and installation relationship of the internal components of the LiDAR system, the maximum detection field of view of the LiDAR may be smaller than the scanning angle of the LiDAR scanning motor. Therefore, when designing the LiDAR, it is necessary to consider the constraints of the design parameters and installation relationship of the internal components of the LiDAR system on the maximum detection field of view based on the integrity of the emitted laser spot.

[0004] On the other hand, the field of view of the receiving optical system also limits the maximum detection distance of the laser radar and the speed of the scanning motor. The farther the detection target is, the faster the scanning mechanism rotates, and the larger the angle (acute angle) between the laser echo direction vector and the laser emission direction vector is. If it exceeds the field of view of the receiving optical system, the received beam cannot be detected by the photosensitive surface. Therefore, the design of the laser radar also needs to consider the limitation of the field of view of the receiving optical system. Summary of the invention

[0005] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art, to provide a method for determining the maximum detection field angle and detection distance of a mechanical scanning laser radar, to solve the problem that the structural design of the mechanical scanning laser radar does not match the detection target range, and to simplify the design process of the laser radar and to improve the design reliability of the laser radar, which is of great significance.

[0006] The technical solution of the present invention is: a method for determining the maximum detection field angle and detection distance of a mechanical scanning laser radar, comprising:

[0007] Establish the laser radar body coordinate system;

[0008] Determine the internal orientation elements and design parameters of the laser radar in combination with the laser radar body coordinate system;

[0009] Establish a transmission link model from laser emission to laser reception in the laser radar system;

[0010] Traverse each scanning angle and calculate the shortest distance between the optical axis of the emission beam and the edge of the scanning mirror according to the internal orientation elements of the laser radar;

[0011] Determine the scanning angle range when the emission light beam is completely reflected by the scanning mirror according to the shortest distance between the optical axis of the emission light beam and the edge of the scanning mirror;

[0012] Within the scanning angle range, calculating the coordinates of the intersection point between the optical axis of the emitted light beam and the scanning mirror and the direction vector of the reflected light beam;

[0013] Calculate the shortest distance between the optical axis of the reflected light beam and the edge of the laser radar optical window glass;

[0014] The maximum detection field angle when the laser is completely emitted from the laser radar optical window glass is determined according to the shortest distance between the optical axis of the reflected light beam and the edge of the laser radar optical window glass;

[0015] Within the maximum detection field angle, traverse each detection distance and scanning motor speed, and calculate the normal vector of the scanning mirror when the laser echo reaches the scanning mirror;

[0016] Calculate the angle between the laser echo direction vector and the laser emission direction vector according to the internal orientation elements and design parameters of the laser radar;

[0017] According to the relationship between the angle and the design parameters, a maximum detection distance model corresponding to different scanning motor rotation speeds is obtained.

[0018] Furthermore, the internal orientation elements of the laser radar also include the coordinates of the laser emission origin, the laser emission direction vector, the radius of the emitted laser beam, the coordinates of the scanning axis center point, the scanning axis direction vector, the initial normal direction vector of the scanning mirror, the initial direction vector of the scanning mirror edge, the normal vector of the inner surface of the optical window glass, the distance from the coordinate origin to the inner surface of the optical window glass, the direction vector of the edge of the inner surface of the optical window glass, the normal vector of the receiving plane, and the field of view angle of the receiving optical system; according to the relationship between the angle and the field of view angle of the receiving optical system, the maximum detection distance model corresponding to different scanning motor speeds is obtained.

[0019] Furthermore, the receiving plane is a virtual or actual plane perpendicular to the optical axis of the receiving optical system, and the normal vector of the receiving plane is consistent with the laser emission direction vector.

[0020] Furthermore, if there are multiple edges of the scanning mirror that may cut the emission light beam, the shortest distance between the optical axis of the emission light beam and all the edges of the scanning mirror is calculated as a common constraint.

[0021] Furthermore, the scanning angle range for determining when the emission light beam is completely reflected by the scanning mirror requires maintaining the integrity of the emission light beam spot, that is, requiring that all laser spots within the Gaussian radius be completely reflected by the scanning mirror; if the shortest distance between the optical axis of the emission light beam and the edge of the scanning mirror is equal to the laser beam radius and the emission light beam is within the scanning mirror, then the integrity requirement of the emission light beam spot is met.

[0022] Furthermore, if the optical window glass of the laser radar has multiple edges that may cut the reflected light beam, the shortest distance between the optical axis of the reflected light beam and all edges of the optical window glass is calculated as a common constraint.

[0023] Furthermore, the determination of the maximum detection field angle when the laser is completely emitted from the laser radar optical window glass requires maintaining the integrity of the light spot of the laser emitted from the optical window glass, that is, requiring that the laser spot will completely pass through the optical window glass within the Gaussian radius; if the shortest distance between the optical axis of the reflected light beam and the edge of the laser radar optical window glass is equal to the laser beam radius and the reflected light beam is within the scanning mirror, then the light spot integrity requirement of the laser emitted from the optical window glass is met.

[0024] Furthermore, the maximum detection field angle is the angle formed when the optical axis of the reflected light beam is tangent to the edge of the optical window glass and its direction vector is projected into a specific plane, and the plane is determined by the actual structure of the laser radar.

[0025] Furthermore, the inner and outer surfaces of the optical window glass are parallel to each other.

[0026] A computer program product includes a computer program / instruction, which, when executed by a processor, implements the steps of a method for determining the maximum detection field of view and detection distance of a mechanical scanning laser radar.

[0027] The advantages of the present invention compared with the prior art are:

[0028] (1) The present invention establishes a laser beam transmission link model and geometric constraint relationship based on the design model parameters of the mechanical scanning laser radar, and can conveniently and quickly obtain the maximum detection field of view and detection distance of the mechanical scanning laser radar;

[0029] (2) The present invention provides the relationship between the maximum detection distance of the mechanical scanning laser radar and the speed of the scanning motor, thereby simplifying the design and optimization process of the mechanical scanning laser radar;

[0030] (3) The present invention solves the problem that the structural design of the mechanical scanning laser radar does not match the detection target range, thereby improving the design efficiency and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0032] Figure 1 The figure is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0033] In order to better understand the above technical scheme, the technical scheme of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical scheme of the present invention, rather than limitations on the technical scheme of the present invention. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0034] The following is a further detailed description of a method for determining the maximum detection field angle and detection distance of a mechanical scanning laser radar provided by an embodiment of the present invention in conjunction with the accompanying drawings. Figure 1 , the specific implementation methods may include:

[0035] (1) Establish the laser radar body coordinate system; the laser radar body coordinate system needs to be determined based on the principle that the coordinate origin is fixed and the coordinate axis has a significant structural direction reference.

[0036] (2) Determine the necessary LiDAR internal orientation elements and their design parameters;

[0037] (3) Establish a transmission link model from laser emission to reception in the lidar system;

[0038] (4) Change the scanning angle and calculate the shortest distance between the optical axis of the emission beam and the edge of the scanning mirror;

[0039] (5) according to the result of step (4), determining the scanning angle range when the emitted light beam is completely reflected by the scanning mirror;

[0040] (6) within the scanning angle range of step (5), calculating the coordinates of the intersection point between the optical axis of the emitted light beam and the scanning mirror and the direction vector of the reflected light beam;

[0041] (7) Calculate the shortest distance between the optical axis of the reflected light beam obtained in step (6) and the edge of the laser radar optical window glass;

[0042] (8) According to the result of step (7), determine the maximum detection field angle when the laser is completely emitted from the laser radar optical window glass;

[0043] (9) within the detection field of view obtained in step (8), changing the detection distance and the scanning motor speed, and calculating the normal vector of the scanning mirror when the laser echo reaches the scanning mirror;

[0044] (10) According to the design of the laser emission and echo receiving optical system, calculate the angle between the laser echo direction vector and the laser emission direction vector (take the acute angle);

[0045] (11) According to the relationship between the angle obtained in step (10) and the field of view angle of the receiving optical system, a maximum detection distance model corresponding to different scanning motor speeds is obtained.

[0046] In the step (1), the laser radar body coordinate system needs to be determined based on the principle that the coordinate origin is fixed and the coordinate axis has a significant structural direction reference.

[0047] The internal orientation elements in step (2) mainly include the coordinates of the laser emission origin, the laser emission direction vector, the radius of the emitted laser beam, the coordinates of the center point of the scanning axis, the direction vector of the scanning axis, the initial normal direction vector of the scanning mirror, the initial direction vector of the edge of the scanning mirror, the normal vector of the inner surface of the optical window glass, the distance from the coordinate origin to the inner surface of the optical window glass, the direction vector of the edge of the inner surface of the optical window glass, the normal vector of the receiving plane, and the field of view of the receiving optical system. In addition, the receiving plane is a virtual or actual plane perpendicular to the optical axis of the receiving optical system, and the normal vector of the receiving plane is consistent with the laser emission direction vector.

[0048] The laser transmission link model in step (3) mainly includes: a rotation model of the normal vector of the mechanical scanning mirror with the mechanical scanning axis, and the initial normal vector of the scanning mirror is The scanning axis direction vector is The scanning axis rotation angle is θ, and the normal vector of the scanning mirror after rotation for:

[0049]

[0050] Laser emission direction vector The direction vector after being reflected by the scanning mirror for:

[0051]

[0052] The laser echo direction vector after being reflected by the scanning mirror and emitted from the optical window glass and reflected by the target for:

[0053]

[0054] The laser echo enters the laser radar and reaches the mechanical scanning mirror. At this time, the scanning axis rotates at an angle of θ′ and the normal vector of the scanning mirror is for:

[0055]

[0056] The direction vector of the laser echo reflected by the scanning mirror and finally entering the receiving optical system for:

[0057]

[0058] In the above steps (4) and (5), if there are multiple scanning mirrors on the scanning motor, it is necessary to consider whether the emitted light beam is

[0059] Each scanning mirror reflects the critical situation. In addition, if there are multiple edges of the scanning mirror that may cut the emission beam, it is necessary to calculate the shortest distance between the optical axis of the emission beam and all the edges of the scanning mirror to consider their common constraints.

[0060] The requirement in step (5) to maintain the integrity of the emission beam spot is that all laser spots within the Gaussian radius are completely reflected by the scanning mirror. If the shortest distance between the emission beam optical axis and the edge of the scanning mirror in step (4) is equal to the laser beam radius and the emission beam is within the scanning mirror, the integrity requirement of the emission beam spot is met. In addition, the beam divergence angle of the emission beam is usually less than milliradians, so when the laser propagates in a small laser radar, the change in its beam radius is generally negligible.

[0061] In the steps (7) and (8), if there are multiple edges of the optical window glass that may cut the reflected light beam, it is necessary to calculate the shortest distance between the optical axis of the reflected light beam and all the edges of the optical window glass to consider their common constraints.

[0062] In the step (8), it is required to maintain the integrity of the laser spot emitted from the optical window glass, that is, it is required that the laser spot will completely pass through the optical window glass within the Gaussian radius. If the shortest distance between the optical axis of the reflected light beam and the edge of the laser radar optical window glass in step (7) is equal to the laser beam radius and the reflected light beam is within the scanning mirror, then the integrity requirement of the laser spot emitted from the optical window glass is met. In addition, the maximum detection field of view is the angle formed by the projection of the direction vector of the reflected light beam in a certain plane when the optical axis of the reflected light beam is just tangent to the edge of the optical window glass. The plane is determined by the actual structure of the laser radar. The thickness of the optical window glass is generally much smaller than the optical path of the laser inside the laser radar, and also much smaller than the distance of the detection target relative to the laser radar. Therefore, its influence on the detection field of view of the laser radar can be ignored.

[0063] In step (9), it is necessary to calculate the time it takes for the laser to travel back and forth between the detection target and the laser radar. At this time, the transmission distance of the laser inside the scanner can be ignored because it is much smaller than the distance from the laser radar to the detection target.

[0064] In step (10), the inner and outer surfaces of the optical window glass are parallel to each other, so the propagation direction of the laser remains unchanged before and after passing through the optical glass. Since the detection distance of the laser radar is usually much smaller than the distance that light travels in one second, the position and posture of the laser radar relative to the target can be considered unchanged during the extremely short laser round trip time, so the laser echo direction vector is parallel to the reflected laser direction vector but in the opposite direction. In addition, the effect of the thickness of the optical window glass on the laser round trip flight time is also negligible.

[0065] In step (11), the laser echo can be received by the receiving optical system only if the angle obtained in step (10) is smaller than the field of view angle of the receiving optical system.

[0066] In the solution provided in the embodiment of the present invention, a method for determining the maximum detection field angle and detection distance of a mechanical scanning laser radar is as follows: Figure 1 As shown, the method of the present invention is specifically implemented as follows:

[0067] (1) Establish the laser radar body coordinate system, including:

[0068] The laser radar body coordinate system is determined based on the principle that the coordinate origin is fixed and the coordinate axis has a significant structural direction reference.

[0069] (2) Determine the necessary laser radar internal orientation elements and their design parameters, including:

[0070] Determine the internal orientation elements and their parameters, including the laser emission origin coordinates, the laser emission direction vector, the emitted laser beam radius, the scanning axis center coordinates, the scanning axis direction vector, the scanning mirror initial normal direction vector, the scanning mirror edge initial direction vector, the optical window glass inner surface normal vector, the distance from the coordinate origin to the optical window glass inner surface, the direction vector of the optical window glass inner surface edge, the receiving plane normal vector, and the receiving optical system field of view angle. In addition, the receiving plane is a virtual or actual plane perpendicular to the optical axis of the receiving optical system, and the receiving plane normal vector is consistent with the laser emission direction vector.

[0071] (3) Establish a transmission link model from laser emission to laser reception in the lidar system, including:

[0072] The normal vector of the mechanical scanning mirror rotates with the mechanical scanning axis. Assume that the initial normal vector of the scanning mirror is The scanning axis direction vector is The scanning axis rotation angle is θ, then the normal vector of the scanning mirror after rotation is for:

[0073]

[0074] Laser emission direction vector The direction vector after being reflected by the scanning mirror for:

[0075]

[0076] The laser echo direction vector after being reflected by the scanning mirror and emitted from the optical window glass and reflected by the target for:

[0077]

[0078] The laser echo enters the laser radar and reaches the mechanical scanning mirror. At this time, the scanning axis rotates at an angle of θ′ and the normal vector of the scanning mirror is for:

[0079]

[0080] The direction vector of the laser echo reflected by the scanning mirror and finally entering the receiving optical system for:

[0081]

[0082] (4) Change the scanning angle and calculate the shortest distance between the optical axis of the emission beam and the edge of the scanning mirror, including:

[0083] Since each scanning surface of the scanning mirror has a boundary, the emitted light beam may be cut by the edge of the scanning mirror during the rotation of the scanning mirror, resulting in that it cannot be completely reflected. Therefore, it is necessary to first calculate the critical situation when the emitted light beam is reflected by the scanning mirror.

[0084] Assume that the origin of the coordinate system is O, the center of the scanning axis is P, the starting point of the emitted light beam is Q, a point on the edge of the scanning mirror is A, and the vector connecting point O and point P is The vector connecting point O and point Q is The vector connecting point O and point A is The vector connecting point P and point A is Calculated using the Rodriguez formula The rotated vector is:

[0085]

[0086] Then we can get The vector after rotation around the scanning axis is:

[0087]

[0088] Assume the initial direction vector of the scanning mirror edge is Then the direction vector after rotation is:

[0089]

[0090] The vector connecting point A' and point Q is:

[0091]

[0092] Laser emission vector and The normal vectors that together make up the plane are:

[0093]

[0094] So the shortest distance between the laser beam and the edge of the rotating scanning mirror is:

[0095]

[0096] (5) Determine the scanning angle range when the emitted light beam is completely reflected by the scanning mirror, specifically including:

[0097] Assume that the radius of the laser is r. Since the beam divergence angle of the emitted light beam is usually less than milliradian, the change in the beam radius is generally negligible when the laser propagates in a small laser radar. If |d1|=r, the laser beam is tangent to the edge of the scanning mirror. It is also possible to determine whether the laser has completely entered the scanning mirror based on the positive or negative sign of d1 based on the specific definition.

[0098] After obtaining the shortest distance d1 (chord-center distance) between the laser emission beam and the edge of the rotating scanning mirror, the effective scanning area of ​​the laser when it is cut by the edge of the scanning mirror can be calculated:

[0099]

[0100] In order to make the results more intuitive, the effective scanning area ratio can be calculated:

[0101] S r =S eff / (π·r 2 ) (13)

[0102] In order to maintain the integrity of the emitted beam spot, it is required that all laser spots within the Gaussian radius will be completely reflected by the scanning mirror, that is, S r =1, then the scanning angle range of the scanning mirror can be obtained.

[0103] (6) Within the above scanning angle range, the coordinates of the intersection of the optical axis of the emitted light beam and the scanning mirror and the direction vector of the reflected light beam are calculated, specifically including:

[0104] From formula (1) and formula (9), the vertical distance from the starting point Q of the emission beam to the scanning mirror can be obtained as:

[0105]

[0106] Therefore, the propagation distance from point Q to the intersection point K1 of the laser and the scanning mirror is:

[0107]

[0108] In this way, the coordinates of point K1 can be obtained:

[0109]

[0110] The direction vector of the reflected beam It has been obtained by formula (2).

[0111] (7) Calculate the shortest distance between the optical axis of the reflected light beam and the edge of the laser radar optical window glass, including:

[0112] Since the optical window glass also has boundaries, the laser light completely reflected by the scanning mirror may be cut by the edge of the optical window glass and cannot pass through the optical window glass to the distance. Therefore, it is necessary to calculate the critical situation when the reflected light beam passes through the optical window glass.

[0113] Suppose a point on the edge of the optical window glass is B, and the direction vector of the edge is The vector connecting point K1 and point B is The laser reflection direction vector and The normal vectors of the plane are:

[0114]

[0115] So the shortest distance between the optical axis of the laser reflected beam and the edge of the optical window glass can be obtained as:

[0116]

[0117] (8) Determine the maximum detection field of view when the laser is completely emitted from the laser radar optical window glass, including:

[0118] If |d2|=r, the reflected laser beam is tangent to the edge of the optical window glass. Based on the specific definition, the positive and negative signs of d2 can be used to determine whether the laser completely passes through the optical window glass. In order to maintain the integrity of the reflected beam spot, it is required that all laser spots within the Gaussian radius pass through the optical window glass completely, so the corresponding scanning angle range of the scanning mirror can be obtained. The maximum detection field angle is the angle formed by the projection of the direction vector of the reflected beam in a specific plane when the optical axis of the reflected beam is just tangent to the edge of the optical window glass. The plane is determined by the actual structure of the laser radar.

[0119] (9) Within the above detection field of view, the detection distance and the scanning motor speed are changed to calculate the normal vector of the scanning mirror when the laser echo reaches the scanning mirror, specifically including:

[0120] When calculating the time it takes for the laser to travel back and forth between the target and the LiDAR, the transmission distance of the laser inside the LiDAR can be ignored, because it is much smaller than the distance from the LiDAR to the target. In addition, the effect of the thickness of the optical window glass on the round-trip flight time of the laser can also be ignored.

[0121] Assuming the distance between the target object and the origin of the laser radar coordinate system is R, the round-trip flight time of the laser is: t = 2·R / c, where c is the speed of light. After time t, the new rotation angle of the scanning motor is:

[0122] θ′=θ+ω·t (19)

[0123] Where ω is the angular velocity of the scanning motor. So the normal vector of the scanning mirror can be obtained As shown in formula (4).

[0124] (10) Calculate the angle between the laser echo direction vector and the laser emission direction vector (acute angle), specifically including:

[0125] Let the normal vector of the inner surface of the window be Then the distance from point K1 to the inner surface of the optical window glass is:

[0126]

[0127] The propagation distance of the reflected light beam from point K1 to its intersection with the inner surface of the window K2 is:

[0128]

[0129] Then we can get the coordinates of point K2:

[0130]

[0131] Considering that the inner and outer surfaces of the optical window glass are parallel to each other, the propagation direction of the laser remains unchanged before and after passing through the optical glass. And because the detection distance of the laser radar is usually much smaller than the distance that light travels in one second, the position and posture of the laser radar relative to the target can be considered unchanged during the extremely short laser round trip time. Therefore, the laser echo passes through point K2 and its direction vector is parallel to the direction vector of the reflected laser but in the opposite direction.

[0132] The laser echo direction vector given by formula (5) is and the normal vector of the receiving plane The angle between the receiving beam direction vector and the receiving plane normal vector can be calculated (acute angle):

[0133]

[0134] (11) According to the relationship between the angle obtained in step (10) and the field of view angle of the receiving optical system, a maximum detection distance model corresponding to different scanning motor speeds is obtained, which specifically includes:

[0135] Assuming the field of view of the receiving optical system is β, then α<β must be satisfied so that the receiving light beam can smoothly enter the receiving optical system and be detected by the photosensitive surface. Based on this constraint, the maximum detection distance model corresponding to different scanning motor speeds can be finally obtained.

[0136] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

[0137] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A method for determining the maximum detection field angle and detection range of a mechanical scanning laser radar, characterized in that: include: Establish the laser radar body coordinate system; Determine the internal orientation elements and design parameters of the laser radar based on the laser radar body coordinate system; Establish a transmission link model from laser emission to reception in the lidar system; Traverse each scanning angle and calculate the shortest distance between the optical axis of the emission beam and the edge of the scanning mirror based on the orientation elements in the laser radar; Determine the scanning angle range when the emission light beam is completely reflected by the scanning mirror according to the shortest distance between the optical axis of the emission light beam and the edge of the scanning mirror; Within the scanning angle range, calculating the coordinates of the intersection point between the optical axis of the emitted light beam and the scanning mirror and the direction vector of the reflected light beam; Calculating the shortest distance between the optical axis of the reflected light beam and the edge of the laser radar optical window glass; The maximum detection field angle when the laser is completely emitted from the laser radar optical window glass is determined according to the shortest distance between the optical axis of the reflected light beam and the edge of the laser radar optical window glass; Within the maximum detection field angle, traverse each detection distance and scanning motor speed, and calculate the normal vector of the scanning mirror when the laser echo reaches the scanning mirror; Calculate the angle between the laser echo direction vector and the laser emission direction vector based on the internal orientation elements and design parameters of the laser radar; According to the relationship between the angle and the design parameters, a maximum detection distance model corresponding to different scanning motor speeds is obtained.

2. The method for determining the maximum detection field angle and detection range of a mechanical scanning laser radar according to claim 1, characterized in that: The internal orientation elements of the laser radar also include the coordinates of the laser emission origin, the laser emission direction vector, the radius of the emitted laser beam, the coordinates of the scanning axis center point, the scanning axis direction vector, the initial normal direction vector of the scanning mirror, the initial direction vector of the scanning mirror edge, the normal vector of the inner surface of the optical window glass, the distance from the coordinate origin to the inner surface of the optical window glass, the direction vector of the edge of the inner surface of the optical window glass, the normal vector of the receiving plane, and the field of view angle of the receiving optical system; according to the relationship between the angle and the field of view angle of the receiving optical system, the maximum detection distance model corresponding to different scanning motor speeds is obtained.

3. The method for determining the maximum detection field angle and detection range of a mechanical scanning laser radar according to claim 2, characterized in that: The receiving plane is a virtual or actual plane perpendicular to the optical axis of the receiving optical system, and the normal vector of the receiving plane is consistent with the laser emission direction vector.

4. The method for determining the maximum detection field angle and detection range of a mechanical scanning laser radar according to claim 1, wherein: If there are multiple edges on the scanning mirror that may cut the emission beam, the shortest distance between the optical axis of the emission beam and all edges of the scanning mirror is calculated as a common constraint.

5. The method for determining the maximum detection field angle and detection range of a mechanical scanning laser radar according to claim 1, characterized in that: The scanning angle range for determining when the emitted light beam is completely reflected by the scanning mirror requires maintaining the integrity of the emitted light beam spot, that is, all laser spots within the Gaussian radius are required to be completely reflected by the scanning mirror; if the shortest distance between the optical axis of the emitted light beam and the edge of the scanning mirror is equal to the laser beam radius and the emitted light beam is within the scanning mirror, then the integrity requirement of the emitted light beam spot is met.

6. The method for determining the maximum detection field angle and detection range of a mechanical scanning laser radar according to claim 1, characterized in that: If the laser radar's optical window glass has multiple edges that may cut the reflected beam, the shortest distance between the optical axis of the reflected beam and all edges of the optical window glass is calculated as a common constraint.

7. The method for determining the maximum detection field angle and detection range of a mechanical scanning laser radar according to claim 1, characterized in that: The determination of the maximum detection field of view angle when the laser is completely emitted from the laser radar optical window glass requires maintaining the integrity of the light spot of the laser emitted from the optical window glass, that is, the laser spot is required to completely pass through the optical window glass within the Gaussian radius; if the shortest distance between the optical axis of the reflected light beam and the edge of the laser radar optical window glass is equal to the laser beam radius and the reflected light beam is within the scanning mirror, then the light spot integrity requirement of the laser emitted from the optical window glass is met.

8. The method for determining the maximum detection field angle and detection range of a mechanical scanning laser radar according to claim 1, characterized in that: The maximum detection field of view angle is the angle formed by the projection of the direction vector of the reflected light beam into a specific plane when the optical axis of the reflected light beam is tangent to the edge of the optical window glass. The plane is determined by the actual structure of the laser radar.

9. The method for determining the maximum detection field angle and detection range of a mechanical scanning laser radar according to claim 1, characterized in that: The inner and outer surfaces of the optical window glass are parallel to each other.

10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instruction is executed by a processor, the steps of the method according to any one of claims 1 to 9 are implemented.

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