Signal crosstalk measurement system and method for multi-line lidar

Abstract

The application provides a signal crosstalk measurement system and method of a multi-line laser radar, wherein the system comprises: the signal crosstalk measurement system comprises a target mounting seat, a laser emitter, a signal output device and a controller; the multi-channel receiving unit of the multi-line laser radar to be measured is placed opposite the target mounting seat, wherein the first target is an object with a diffuse reflection characteristic of low reflectivity, so that the output signal of any receiving unit in the multi-channel receiving unit is below the background noise; and the second target is an object with a specular reflection characteristic; the power-adjustable light beam output by the laser emitter covers the multi-channel receiving unit after being reflected by the second target; the controller is electrically connected with the laser emitter and the signal output device, respectively, and is used for generating the signal crosstalk parameters corresponding to the multi-channel receiving unit according to the output signal of the multi-channel receiving unit. The application can accurately measure the signal crosstalk of the multi-line laser radar.

Claims

1. A method for measuring signal crosstalk in a multi-line lidar system, characterized in that, The signal crosstalk measurement method is applied to a signal crosstalk measurement system, which includes a target mounting base, a laser emitter, a signal output device, and a controller. The target mounting base is equipped with a first target and a second target. Opposite the target mounting base is a multi-channel receiving unit of the multi-line lidar to be measured. The first target is an object with low reflectivity and diffuse reflection characteristics, which makes the output signal of any receiving unit in the multi-channel receiving unit below the noise floor. The second target is an object with specular reflection characteristics. The laser emitter is used to output a beam with adjustable power, and the beam covers the multi-channel receiving unit after being reflected by the second target; The signal output device is electrically connected to the multi-channel receiving unit and is used to receive the output signal of the multi-channel receiving unit. The controller is electrically connected to the laser transmitter and the signal output device respectively, and is used to control the output power of the laser transmitter and receive the output signal of the multi-channel receiving unit forwarded by the signal output device; The controller is also configured to generate signal crosstalk parameters corresponding to the multi-channel receiving unit based on the output signal of the multi-channel receiving unit; The signal crosstalk measurement method includes: The field of view of the first receiving unit in the multi-channel receiving unit is determined according to the standard diffuse reflector and the first preset method, and the field of view angle of the laser emitter is adjusted so that the emitted beam covers the field of view of the first receiving unit; wherein, the first receiving unit is any one of the receiving units in the multi-channel receiving unit; The first target is placed at a preset position opposite the first receiving unit; wherein, at the preset position, the output signal of the first receiving unit corresponding to the power adjustment range of the laser emitter is below the noise floor. The second target is placed at a first position in the field of view of the first receiving unit, and the output signal of the first receiving unit and the first output signal of the second receiving unit are measured; wherein, the second receiving unit is any one of the multi-channel receiving units other than the first receiving unit; The second target is placed at a second position in the field of view of the first receiving unit according to a second preset method, and the second target is placed at the second position. The second output signal of the second receiving unit is measured. The output signal of the first receiving unit measured at the second position is the same as the output signal of the first receiving unit measured at the first position. Based on the first output signal and the second output signal, the signal crosstalk parameters corresponding to the first receiving unit are generated.

2. The signal crosstalk measurement method for multi-line lidar according to claim 1, characterized in that, The first target is a black diffuse reflective panel with a reflectivity of 0.3% to 2%; The second target is a reflective material with a smooth surface; The signal output device is an oscilloscope.

3. The signal crosstalk measurement method for multi-line lidar according to claim 2, characterized in that, The step of determining the field of view of the first receiving unit in the multi-channel receiving unit according to the standard diffuse reflector and the first preset method includes: A light beam is shone onto the standard diffuse reflector and moved horizontally along the Y direction. The horizontal position Ym corresponding to the maximum output signal amplitude of the first receiving unit is recorded during the movement. The distance between the standard diffuse reflector and the first receiving unit is L. The beam is moved vertically along the Z direction, and the maximum output signal amplitude Vm of the first receiving unit and the vertical position Zm corresponding to Vm are recorded during the movement. A coordinate system is established with the intersection of the line where the horizontal position Ym is located and the line where the vertical position Zm is located as the origin, the X-axis horizontally to the right as the positive direction, the Y-axis horizontally forward as the positive direction, and the Z-axis vertically downward as the positive direction. Move the beam along the negative Z-axis from Zm and record the output signal amplitude as it decreases. Distance traveled by the time beam Move the beam along the positive Z-axis from Zm, and record the output signal amplitude as it decreases. Distance traveled by the time beam Move the beam along the positive Y-axis from point Ym and record the output signal amplitude as it decreases. Distance traveled by the time beam Move the beam along the negative Y-axis from point Ym and record the output signal amplitude as it decreases. Distance traveled by the time beam ; Will The vertical field of view of the first receiving unit is determined, and The horizontal field of view of the first receiving unit is determined.

4. The signal crosstalk measurement method for multi-line lidar according to claim 3, characterized in that, Determining the second position of placing the second target in the field of view of the first receiving unit according to the second preset method includes: Move the second target up and down to determine the second position.

5. The signal crosstalk measurement method for multi-line lidar according to claim 2, characterized in that, Determining the second position of placing the second target in the field of view of the first receiving unit according to the second preset method includes: Increase the power output of the laser emitter, reduce the size of the second target, and then move the reduced second target up and down to determine the second position.

6. The signal crosstalk measurement method for multi-line lidar according to claim 2, characterized in that, The step of generating signal crosstalk parameters corresponding to the first receiving unit based on the first output signal and the second output signal includes: The change in the first output signal and the second output signal is determined as the optical signal crosstalk parameter for the field of view corresponding to the first position to the second position.

7. The signal crosstalk measurement method for multi-line lidar according to claim 2, characterized in that, The step of generating signal crosstalk parameters corresponding to the first receiving unit based on the first output signal and the second output signal includes: The second output signal is determined as the electrical signal crosstalk parameter of the first receiving unit to the second receiving unit in the case of the output signal of the first receiving unit.

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