A variable lidar scanning angle device

Abstract

The present invention discloses a variable lidar scanning angle device. For a single-light-source airborne LiDAR, a scanning device is essential. There are problems with low scanning accuracy in galvanometer scanning, while it is difficult to change the scanning angle of a rotating refractive prism scanner. The device designed in the present invention has optical wedges of 2°, 4°, and 6° inside. The micro servo motor inside the hollow motor is controlled to rotate through the CC2530 radio transceiver circuit. The micro servo motor then drives the dragging mechanism to make the optical wedge enter or leave the field of view, thereby changing the scanning angle of the lidar. The airborne lidar with multiple scanning angles can freely select the flight altitude and can undertake more detection tasks.

Description

Technical Field

[0001] The present invention relates to the field of lidar, and particularly to a novel mechanical structure design, which is mainly applied to the occasion of ground object scanning by an airborne single-point lidar. Technical Background

[0002] At present, the scanning methods of airborne lidar include linear array scanning, area array scanning, rotating refraction prism scanning, galvanometer scanning, etc. Linear array scanning and area array scanning belong to the scanning methods of multiple laser light sources, while rotating refraction prism and galvanometer scanning belong to the scanning methods of single laser light source. Linear array scanning and area array scanning still require imported laser arrays, and the corresponding APD arrays are embargoed internationally. The scanning method of a single laser light source is still the main scanning method. There are some existing lidar scanning devices with variable scanning angles, but they all belong to the galvanometer scanning method. At present, compared with the galvanometer scanning method, the scanning method of the rotating refraction prism has the advantages of high precision and large scanning density, but it is difficult to change its own scanning angle. Aiming at the disadvantages of the rotating refraction prism scanning method, the present invention designs a novel scanning device, which can select the scanning angle of the lidar, thereby increasing or decreasing the scanning range of the radar or freely selecting the flight altitude. Make the radar suitable for more usage occasions. Summary of the Invention

[0003] The present invention improves the disadvantage that the traditional rotating refraction prism scanning method cannot change the scanning angle, and designs a novel device, which enables the radar to select the scanning angle and increase or decrease the scanning range. Adapt to more usage occasions.

[0004] The present invention can be realized by the following technical solutions: A hollow rotating platform with a diameter of 340 (mm) is used to load the device to achieve the purpose of rapid rotation. One optical wedge each of 2°, 4°, and 6° has different refractive powers for light, which causes the light to have different deflection angles when passing through them, thereby generating different scanning angles. Two circuit boards carrying CC2530 chips, one for transmitting radio signals and one for receiving radio signals. Three 3.3V micro DC servo motors. Three roller guides. In this patent, the CC2350 transmitting circuit is controlled by an external button. After the receiving end receives the signal, the DC servo motor is started to drive the guide rail to operate, and the optical wedge lens is pulled into the center of the field of view. When the scanning angle needs to be changed, the external reset button is pressed, the servo motor rotates in the reverse direction to pull the optical wedge lens out of the field of view, and then the start button corresponding to the required scanning angle is pressed to realize the function of scanning angle switching.

[0005] The application number CN201910115132.1 designs a pendulum lidar scanner, but there are two disadvantages. One is that its scanning accuracy using the galvanometer scanning structure is lower than that of the rotating refraction prism scanning method. The other is that it cannot perform scanning angle transformation.

[0006] An effective improvement of the present invention is that: optical wedges with different wedge angles are added to the scanning device, enabling the radar to have multiple scanning ranges and better adapting to different flight altitudes and terrains of the aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The following further describes the embodiments and various possible modifications of the present invention in conjunction with the accompanying drawings.

[0008] Figure 1 are views of the present invention in various directions

[0009] wherein a is the front view, b is the left view, c is the right view, d is the top view, e is the bottom view, and f is the regular isometric view

[0010] Figure 2 is the overall exploded view of the present invention

[0011] Figure 3 is the working principle of the present invention

[0012] Figure 4 is the guide rail designed in the present invention

[0013] Figure 5 is the optical wedge lens holder designed in the present invention SPECIFIC EMBODIMENTS

[0014] The following further describes the specific implementation of the present invention in conjunction with the accompanying drawings.

[0015] Example:

[0016] Combined with Figure 1 are the views of the present invention in various directions, where a is the front view, b is the left view, c is the right view, d is the top view, e is the bottom view, and f is the regular isometric view.

[0017] Combined with Figure 2 is the exploded view of the present invention. 1 is the protective end cover lens, 2 is the protective end cover for preventing dust from falling. 3 is the keyboard with 6 buttons that can trigger the internal circuit key positions and emit relevant signal instructions while preventing dust from falling into the circuit. 4 is the transmitting end cc2530 chip, 5 is the power supply of the transmitting end circuit board, 6 is the transmitting end circuit board. 4, 5, and 6 together constitute the transmitting end circuit. 7 is the hollow motor rotating head for high-speed rotation of the carrier, 8 is the hollow motor, and the motor rotor provides torque for the 7 hollow motor rotating head in this area. 9 is the load housing for carrying optical equipment and electronic devices, 10 is the power supply of the receiving end circuit board, 11 is the receiving end circuit board, 12 is the receiving end cc2530 chip for receiving instructions. 10, 11, and 12 together constitute the receiving end circuit. 13 is the guide rail for sliding the optical wedge, 14 is the 2° optical wedge and its lens holder, 15 is the 4° optical wedge and its lens holder, 16 is the 6° optical wedge and its lens holder. According to the optical theorem, the wedge angle of the optical wedge is equal to the scanning angle, so the present invention has three scanning angles.

[0018] Figure 1 and Figure 2 Generally indicate the installation method of the present invention. It should still be noted that the three guide rails are respectively installed at 1 / 4, 1 / 2, and 3 / 4 of the height of the 9 load-carrying housings.

[0019] Combined with Figure 3 , Figure 3 a is the initial state of the overall device. When the leftmost button in the first row of the 3-keyboard is pressed, the transmitting circuit of cc2530 will transmit a radio signal to the receiving circuit. When the receiving circuit receives the signal, it will start the DC servo motor built in the 13 guide rail to work. The rotation of the DC servo motor causes the guide rail to drive the 2° optical wedge towards the axis of the hollow motor. According to the program written into cc2530, the motor is controlled to rotate for a certain time so that the 2° optical wedge is exactly at the center of the circle of the 9 load-carrying housing. At this time, the scanning angle of the scanning device is 2°, which is Figure 3 state b. When the scanning angle needs to be changed, press the leftmost button in the second row of the 3-keyboard. The transmitting circuit of cc2530 sends a signal to the receiving circuit, and the receiving circuit rotates the motor in the reverse direction to pull the 2° optical wedge out of the field of view area. At this time, it is Figure 3 state c. Press the second button in the first row of the 3-keyboard, the transmitting circuit of cc2530 sends a signal to the receiving circuit, and the receiving circuit controls the rotation of the DC servo motor. The 13 guide rail pulls the 4° optical wedge into the field of view. At this time, it is Figure 3 state d. The function of changing the scanning angle is realized. The working principle of the 6° scanning angle designed in the present invention is the same as above.

[0020] Combined with Figure 4 is the design drawing of the guide rail of the present invention. 1 is the guide rail frame. 2 is the slider. The arc-shaped inner wall of 2 is used for welding the optical wedge mirror base. The two sides of 2 are used for fixing with the guide rail. 3 is the protective ring, which is used for welding with the 9 load-carrying housing in Figure 2 . 4 is the rotating shaft, 5 is the micro DC servo motor, 6 is the slider chute, and 7 is the belt. 4, 5, 6, and 7 jointly drive 2 to slide. The whole guide rail can be made of a metal material with a certain strength, such as Q235-A.

[0021] Such as Figure 5 is the design drawing of the optical wedge mirror base of the present invention. 1 is the area for placing the optical wedge, 2 is the light incident area, and 3 is the light exit area. A 53° chamfer is left in the light incident area.

Claims

1. A variable lidar scanning angle device, comprising: a guide rail, a CC2530 transmitter keyboard, and a protective end cover; characterized in that: the guide rail has an annular guard ring welded to the hollow motor rotating head and can rotate at high speed together with the hollow motor; the CC2530 transmitter keyboard is placed on the flank of the hollow motor rotating head and welded; if the device is applied to the overall radar, it is placed in a directly accessible position; the protective end cover is placed above the hollow motor rotating head; There is an annular guard ring welded to the outside of the guide rail frame; the transmission mechanism is driven by a micro servo motor, and the two guide rail frames are connected by a semi-circular slider; The semi-circular slider is used for welding the optical wedge mirror base and is the carrier of the optical wedge; The guide rail is used for sliding the optical wedge, and the optical wedge includes a 2° optical wedge, a 4° optical wedge, and a 6° optical wedge; The guide rails are respectively installed at 1 / 4, 1 / 2, and 3 / 4 of the height of the load-carrying housing, and the load-carrying housing is used for carrying optical equipment and electronic devices; The center of the protective end cover has a circular hole for placing a glass sheet; there are six cylindrical pins at the bottom for fixing with the hollow motor.

2. A variable lidar scanning angle device according to claim 1, characterized in that: There are six mechanical buttons outside the CC2530 keyboard for triggering six internal circuit contacts.

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