A laser radar device with a prism reflection structure

Abstract

The present application discloses a laser radar device with a prism reflection structure, including a base, a support column, a radar assembly, a rotating mechanism, a reflector and a reflective prism; the radar assembly includes an equipment box, and the equipment box is provided with a laser coaxial transmitter and receiver and a signal processing circuit that are electrically connected to each other; the rotating mechanism is rotatably connected to the base; the rotating axis of the rotating mechanism coincides with the center of the laser coaxial transmitter and receiver; the reflector is tilted and placed on the rotating mechanism, and the angle between the reflector and the horizontal plane is 45°; the reflective prism is arranged above the mirror surface of the reflector, and an incident surface and an exit surface are respectively arranged at both ends; the incident surface is arranged directly below the laser coaxial transmitter and receiver in the horizontal direction; and the exit surface is arranged in the vertical direction. By arranging a reflective prism, the present application enables the laser emitted by the laser transmitting end to be subjected to multiple total reflections, and can scan the area closer to the bottom of the radar, thereby improving the ability of the laser radar to detect small-sized targets on the ground.

Description

Technical Field

[0001] The present invention relates to the technical field of optoelectronic instruments and equipment, and in particular to a laser radar device with a prism reflection structure. Background Art

[0002] Lidar is a radar system that emits laser beams to detect the position, speed and other characteristic quantities of the target. In terms of working principle, there is no fundamental difference from microwave radar: a detection signal (laser beam) is emitted to the target, and then the received signal reflected from the target (target echo) is compared with the emitted signal. After appropriate processing, relevant information about the target can be obtained, such as target distance, direction, height, speed, attitude, and even shape parameters, so as to detect, track and identify targets such as aircraft and missiles.

[0003] With the continuous development of unmanned driving / unmanned warehousing technology, LiDAR has received widespread attention and recognition from various industries, and its application environment has become more complex and demanding. In some application scenarios, LiDAR needs to be closer to the ground to detect small-sized targets on the ground. However, the traditional coaxial system LiDAR uses a common reflector for transmission and reception. However, due to the total aperture of the reflector and the thickness of the motor and motor bracket, the light output position is relatively high and cannot meet the use requirements of specific scenarios. Summary of the invention

[0004] The present application provides a laser radar device with a prism reflection structure to solve the problem in the prior art that the laser beam emission position is relatively high, resulting in missed detection of small-sized objects below the light emission aperture.

[0005] The present application provides a laser radar device with a prism reflection structure, comprising:

[0006] A base; one side of the base is fixedly connected with a support column perpendicular to the base;

[0007] A radar assembly is located above the base, and one side of the radar assembly is fixedly connected to the top of the support column; the radar assembly includes an equipment box, and the equipment box is provided with a laser coaxial transmitter and receiver and a signal processing circuit that are electrically connected to each other; the direction in which the laser coaxial transmitter and receiver transmits and receives the laser beam is perpendicular to the direction of the plane where the base is located;

[0008] A rotating mechanism is disposed between the base and the equipment box and is rotatably connected to the base; the rotating axis of the rotating mechanism coincides with the center of the laser coaxial transmitter and receiver;

[0009] A reflector is fixed on the rotating mechanism; the reflector is placed at an angle, and forms an angle of 45° with the horizontal plane;

[0010] A reflecting prism is arranged above the mirror surface of the reflecting mirror; an incident surface and an exit surface are respectively arranged at two ends of the reflecting prism; the incident surface is arranged directly below the laser coaxial transmitter and receiver in the horizontal direction; and the exit surface is arranged in the vertical direction.

[0011] Optionally, the cross-section of the reflecting prism is trapezoidal.

[0012] Optionally, the laser emitted by the laser coaxial transmitter-receiver is totally reflected at least three times inside the reflective prism.

[0013] Optionally, one end of the reflecting prism extends out of the reflecting mirror.

[0014] Optionally, the reflecting prism and the reflecting mirror are detachably connected.

[0015] It can be seen from the above technical solutions that the laser radar device with a prism reflection structure provided by the present application has the following beneficial effects:

[0016] 1. The reflective prism used in this application can achieve total reflection of the laser, with no loss of reflected energy and no weakening of the scanning effect;

[0017] Second, this application can reduce the height value D of the emitted light beam, thereby improving the ability of the laser radar to detect small-sized targets on the ground, and has wider applicability;

[0018] 3. This application can change the device configuration structure at any time according to different on-site needs to achieve the best emission height, which is more flexible. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the embodiments are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0020] Figure 1 This is a schematic structural diagram of a laser radar device with a prism reflection structure according to the present application;

[0021] Figure 2 for Figure 1 a right side view of the device shown;

[0022] Figure 3 A working principle diagram of a laser radar device with a prism reflection structure for this application;

[0023] Figure 4 The figure is a position relationship diagram of a reflecting prism and a reflecting mirror in a feasible embodiment.

[0024] In the figure, 1-base, 2-support column, 3-equipment box, 31-laser coaxial transmitter and receiver, 32-signal processing circuit, 4-rotation mechanism, 5-reflection prism, 51-incident surface, 52-exit surface, 6-reflector. DETAILED DESCRIPTION

[0025] Embodiment 1

[0026] See also Figure 1 , is a schematic structural diagram of a laser radar device with a prism reflection structure in the present application;

[0027] Depend on Figure 1 It can be seen that a laser radar device with a prism reflection structure provided in an embodiment of the present application includes:

[0028] Base 1; Base 1 is used to support other components of the device. Since the laser radar needs to perform a scanning operation on a certain horizontal plane, the device must have high stability during operation to ensure that the scanning surface is in the same plane. Therefore, in some embodiments, the base 1 can be fixed on a horizontal plane (such as a laboratory workbench, a flat ground, etc.) in various forms. The fixing form adopted is not limited to bolt fixing, welding fixing or other forms. One side of the base 1 is fixedly connected with a support column 2 perpendicular to the base 1. Various forms of detachable connection can be used between the support column 2 and the base 1 to facilitate the movement of the device, or it can be formed in an integrated manner to increase the stability of the device.

[0029] A radar assembly is located above the base 1, and one side is fixedly connected to the top of the support column 2; in this embodiment, the radar assembly is used to perform operations such as laser emission, echo reception, waveform processing and analysis and calculation, and finally generate a detection result. Therefore, a variety of existing technologies can be used to carry a laser coaxial transmitting and receiving system to achieve the above purpose. Specifically, the radar assembly includes an equipment box 3, which is used to support and fix internal devices and provide protection for the internal devices. The equipment box 3 is provided with a laser coaxial transmitting and receiving receiver 31 and a signal processing circuit 32 that are electrically connected to each other; wherein the laser coaxial transmitting and receiving receiver 31 generally includes a transmitting system composed of a laser and a collimating mirror at the center, and an external nested receiving lens is used for echo energy reception; the signal processing circuit 32 is used to control laser emission, receiving signal processing and calculation, and the main processing principle can adopt the TOF (time of flight) ranging method, calculate the time difference between the receiving echo time and the transmitting time through the flight time, and calculate the distance of the target object according to the fixed speed of light multiplied by the time. The laser coaxial transmitter-receiver 31 transmits and receives the laser beam in a direction perpendicular to the plane where the base 1 is located, so that the emitted laser can be changed from a vertical direction to a horizontal direction under the action of a reflector.

[0030] The rotating mechanism 4 is arranged between the base 1 and the equipment box 3, and is rotatably connected to the base 1; the rotation axis of the rotating mechanism 4 coincides with the center of the laser coaxial transmitter and receiver 31; in the present embodiment, the rotating mechanism 4 is used to hold the reflector, and the placement position of the reflector and the angle between the reflector and the outgoing laser can be changed by rotating the rotating mechanism 4 itself, so that the laser is emitted at different angles along the same horizontal plane after reflection, thereby monitoring all possible objects within a preset angle range. Normally, the rotation angle of the rotating mechanism 4 can be arbitrarily rotated within the range of 0° to 360°. Considering the influence of the support column 2, it should be understood that the reflector can adjust the outgoing laser within a fan-shaped range close to 360°.

[0031] A rotating motor is usually arranged in the rotating mechanism to control the rotating mechanism 4 to rotate along the rotating axis; in this embodiment, the rotating motor is a component for providing the rotating mechanism 4 with rotation, and its specific selection is not limited, and the output of the rotating motor can have a variety of transmission modes, such as gear transmission, gear rack structure, etc. In addition, the rotation control of the rotating motor should be completed by the signal processing circuit, and specifically, the system can generate control instructions to complete the opening and closing control of the rotating motor according to the preset scanning range.

[0032] The reflector 6 is fixed on the rotating mechanism 4. In this embodiment, the reflector 6 is a plane reflector, and its shape can be Figure 2 The circular shape shown in the figure may also be an ellipse or other shapes, depending on actual needs; the reflector 6 is placed at an angle, and an angle of 45° is formed between it and the horizontal plane to ensure that the laser reflected by the reflector 6 is emitted in the horizontal direction;

[0033] The reflecting prism 5 is arranged above the mirror surface of the reflecting mirror 6. In the present embodiment, the reflecting prism 5 can not only change the emission direction of the laser reflected by the reflecting mirror 6, so that the laser is emitted at a lower emission height after several reflections; at the same time, due to the unique structure of the reflecting prism 5, during the reflection process of the laser, all the incident angles on the reflection path are within the range of the total reflection angle, that is, the reflection efficiency is 100%, and there is no energy loss during the reflection process, thereby ensuring the original laser effect; the two ends of the reflecting prism 5 are respectively provided with an incident surface 51 and an exit surface 52; the incident surface 51 is arranged in the horizontal direction directly below the laser coaxial transmitter and receiver 31, corresponding to receiving the laser emitted from the laser coaxial transmitter and receiver; the exit surface 52 is arranged in the vertical direction, corresponding to sending the reflected laser to the pre-scanning area.

[0034] Furthermore, in a feasible embodiment, the reflecting prism 5 can be set as a trapezoidal structure with a trapezoidal cross-section. This shape is not only easy to process, but also has a tight connection structure with the reflector 6, which is conducive to effectively controlling the reflection angle.

[0035] See also Figure 3 , a working principle diagram of a laser radar device with a prism reflection structure in the present application;

[0036] Depend on Figure 3 It can be seen that when the reflecting prism 5 is not set, the laser emitted by the laser coaxial transmitter and receiver 31 is reflected by the reflecting mirror 6 and emitted as the first light beam A; when the reflecting prism 5 is set, the emitted laser will be reflected more than once in the reflecting prism 5, and will eventually be emitted as the second light beam B lower than the plane where the first light beam A is located, and the height difference between the second light beam B and the first light beam A is D; at this time, the emission height is lower and closer to the surface where the base is located (the ground), making it easier to scan objects close to the bottom surface.

[0037] Furthermore, according to the different specific shapes of the reflective prism 5, the laser can be reflected for different times in the reflective prism 5. Correspondingly, with each additional two reflections, the height of the laser emission will be further reduced. Therefore, in a feasible embodiment, in order to ensure that the laser emission height is low, the spacing between the two trapezoidal sides in the reflective prism 5 can be set so that the laser emitted by the laser coaxial transmitter-receiver 31 is totally reflected at least three times inside the reflective prism 5, that is, Figure 3 The situation shown.

[0038] In this embodiment, under the premise that the value of the height difference D is fixed, if the spacing between the two trapezoidal sides in the reflecting prism 5 is changed, the number of total reflections will change (increase or decrease). At this time, it is necessary to consider that increasing the number of total reflections may cause the laser angle to change multiple times, which is not conducive to achieving precise control of the emission angle. Therefore, in some embodiments, a wider trapezoidal side spacing should be selected as much as possible to make the number of reflections as small as possible, so as to achieve the maximum height difference D with the least number of reflections.

[0039] Furthermore, in a feasible embodiment, one end of the reflecting prism 5 may be arranged to extend out of the reflecting mirror 6, such as Figure 4 As shown, at this time, the upper half of the reflecting prism 5 is connected to the reflecting mirror 6, and the emitting surface 52 of the lower half can be close to the surface where the base 1 is located, so that the scanning area can be closer to the ground, and because the lower half of the reflecting prism 5 protrudes out of the base 1, it will not be blocked by the base 1 when it rotates with the rotating mechanism 4.

[0040] Furthermore, since the reflecting prism 5 has various structural forms, different laser emission heights can be obtained by using reflecting prisms of different forms and specifications. Therefore, in multiple different embodiments, the connection between the reflecting prism 5 and the reflecting mirror 6 can be set to be a detachable connection. In this way, reflecting prisms 5 of different specifications can be selected and installed on the reflecting mirror 6 according to actual needs on site to achieve different effects; the connection form between the two is not limited to one, for example, a suction cup connection, a screw connection, and a snap connection are all possible.

[0041] It can be seen from the above technical solution that the working process of the laser radar device provided by the present application is: the laser coaxial transmitter and receiver 31 emits a laser beam vertically downward, the laser enters the reflective prism 5 from the incident surface 51, and after multiple total reflections, it is finally emitted horizontally from the exit surface 52; the echo energy in the scanning area is obtained to the laser coaxial transmitter and receiver 31, and fed back to the signal processing circuit for analysis and processing, and finally the distance of the target object is obtained. In this embodiment, the working process of the laser coaxial transmitter and receiver and the signal processing circuit can adopt known technologies, which will not be repeated here.

[0042] It can be seen from the above technical scheme that the embodiment of the present application provides a laser radar device with a prism reflection structure, including a base; one side of the base is fixedly connected to a support column perpendicular to the base; a radar assembly is located above the base, and one side is fixedly connected to the top of the support column; the radar assembly includes an equipment box, and the equipment box is provided with a laser coaxial transmitter and receiver and a signal processing circuit that are electrically connected to each other; the direction in which the laser coaxial transmitter and receiver transmits and receives the laser beam is perpendicular to the direction of the plane where the base is located; a rotating mechanism is provided between the base and the equipment box, and is rotatably connected to the base; the rotation axis of the rotating mechanism coincides with the center of the laser coaxial transmitter and receiver; a reflector is fixed on the rotating mechanism; the reflector is tilted and has an angle of 45° with the horizontal plane; a reflecting prism is provided above the mirror surface of the reflecting prism; an incident surface and an exit surface are provided at both ends of the reflecting prism respectively; the incident surface is provided directly below the laser coaxial transmitter and receiver in the horizontal direction; and the exit surface is provided in the vertical direction. The present application sets a reflecting prism so that the laser emitted by the laser transmitting end undergoes multiple total reflections, and can scan the area closer to the bottom of the radar, thereby improving the ability of the laser radar to detect small-sized targets on the ground.

[0043] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The specification and examples are to be considered exemplary only, and the true scope and spirit of the present invention are indicated by the following claims.

Claims

1. A laser radar device with a prism reflection structure, characterized in that: include: A base (1); a support column (2) perpendicular to the base (1) is fixedly connected to one side of the base (1); A radar assembly is located above the base (1), and one side of the radar assembly is fixedly connected to the top of the support column (2); the radar assembly comprises an equipment box (3), and a laser coaxial transmitter-receiver (31) and a signal processing circuit (32) are provided inside the equipment box (3), and the direction in which the laser coaxial transmitter-receiver (31) transmits and receives the laser beam is perpendicular to the direction of the plane where the base (1) is located; A rotating mechanism (4) is disposed between the base (1) and the equipment box (3) and is rotatably connected to the base (1); the rotating axis of the rotating mechanism (4) coincides with the center of the coaxial laser transmitter and receiver (31); A reflector (6) is fixed on the rotating mechanism (4); the reflector (6) is placed at an angle, and forms an angle of 45° with the horizontal plane; A reflecting prism (5) is arranged above the mirror surface of the reflecting mirror (6); an incident surface (51) and an exit surface (52) are respectively arranged at two ends of the reflecting prism (5); the incident surface (51) is arranged in the horizontal direction directly below the laser coaxial transmitter and receiver (31); and the exit surface (52) is arranged in the vertical direction; One end of the reflecting prism (5) extends out of the reflecting mirror (6) and the lower half protrudes out of the base (1), and the bottom end of the emitting surface (52) is close to the ground, so that the laser emitted by the laser coaxial transmitting and receiving device (31) is emitted in the horizontal direction of the surface where the base (1) is located after multiple total reflections.

2. The laser radar device according to claim 1, characterized in that: The cross section of the reflecting prism (5) is trapezoidal.

3. The laser radar device according to claim 2, characterized in that: The laser light emitted by the laser coaxial transmitter-receiver (31) is totally reflected at least three times inside the reflecting prism (5).

4. The laser radar device according to claim 1, characterized in that: The reflecting prism (5) and the reflecting mirror (6) are detachably connected.

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