Research On Key Technologies Of Multi-line Scanning LiDAR

The high-speed,high-precision perception of 3D depth information is a key and difficult point in the fields of navigation,obstacle avoidance and driverless driving.Multi-line scanning laser radar has the advantages of fast measuring speed,large measuring range and high measuring precision.It is important equipment for 3D depth information sensing and is the best solution for unmanned obstacle detection.This thesis analyzes the key technologies of multi-line laser radar,and conducts in-depth research on multi-line laser radar crosstalk suppression technology,pulse laser ranging technology and wireless power supply technology.The construction of the multi-line scanning laser radar prototype and the experimental verification is completed.This thesis mainly completed the following work:1.The mathematical model of optical crosstalk of multi-line laser radar was constructed.The distribution law of receiving spot was established,and the constraint of avoiding crosstalk was established.Based on this condition,a multi-line self-collimating optical structure was designed,effectively avoided optical crosstalk between different channels and achieved simultaneous multi-path measurement of distance.2.A high-power pulsed laser driving method with narrow pulse drive discharge and LC resonance pulse width control was proposed,and the mathematical model of this current was constructed.The characteristics of current pulse and ringing were analyzed,and the influence of circuit parameter variation on the peak value of driving current,pulse width and peak value of ringing was determined.According to the conditions of increasing peak value,reducing pulse width and suppressing ringing,the optimal design of the driving circuit parameters was realized and the experimental verification was completed.The driving current with pulse width less than 10 ns,peak value of about 35 A and maximum repetition frequency of 100 k Hz is obtained.In addition,the ringing was effectively suppressed.3.A current feeding and parallel resonant wireless feeding method with automatic frequency tracking function was proposed.The mathematical model of the circuit was constructed.The compact feeding circuit was designed by using the resonant lamp ballast controller integrated chip.In the case of fluctuation of the power supply distance,the tracking of the resonant frequency was completed,the soft switching state of the circuit was ensured,and the electromagnetic compatibility of the feeding circuit was effectively improved.4.A three-line scanning laser radar system was built,then,the error analysis and experimental verification were completed.The experimental results shown that the laser radar system designed in this thesis had a range of 1?50m and accuracy better than 5cm.It could realize 3D depth information perception and obtain the 3D contour map of the measured target.