Design Of Background Light Jammer For Lidar Ranging Performance Detection

The performance testing of laser radar is an important part of the laser radar production process.In order to test the outdoors ranging performance of laser radar under indoor conditions,it is urgent to develop a background light interference signal that can accurately simulate the solar radiation in different wavelengths.Therefore,this paper studies the accurate simulation of the solar background in a specific wavelength,aiming to develop a set of solar background jamming source for the indoor equivalent detection of the ranging performance of radar.On the basis of in-depth data research,the paper proposes a technical scheme for simulating solar interference in the 905 nm,1064nm,1300 nm and 1550 nm bands by using spatially dislocated NIR arrays combined with illumination optical system design,and starting from the simulation requirements of LED luminous efficiency and solar interference,the LEDs were selected by theoretical calculations to determine the number of LED arrays.Introduced an illumination optical system design consisting of a concentrator,a concentrating mirror,a reflective cavity and a collimating mirror.The component modeling was completed in TracePro software,and the LED space arrangement and illumination optical system parameters were optimized according to the collimation and uniformity requirements of the spot.The results show that the light uniformity of 40 cm from the light exit port is less than 5%,the spot diameter is larger than 100 mm,and the irradiance of the light meets the requirements of the index.On this basis,the multi-channel LED driver circuit scheme driven by constant current source is introduced,and the adjustable constant current source driver circuit based on PWM signal dimming is designed to realize the reliable driving of LED array.In addition,the paper completed the software and hardware design and system integration of each component of the background light jammer,and performed the calibration and experimental verification of the system parameters.The results show that the duty ratio of the four-way PWM signal is adjusted from 0% to 99%,and the illuminance of each band satisfies the standard range of 20,000 lux to 100,000 lux.