| At present,autonomous driving technology has been widely used in mobile devices such as cars,robots,and drones,which has promoted the rapid development of my country’s rail transit,logistics,and manufacturing industries.Lidar is the core sensor of autonomous driving technology.The laser ranging system is used to realize obstacle distance detection and navigation and obstacle avoidance.higher requirements.At present,lidar still has problems such as high research and development cost,difficult system design,and poor laser ranging accuracy.Therefore,the research and design of low-cost,miniaturized and high-precision pulsed laser ranging system are carried out.The main design work completed in this project is as follows:(1)Research the principle and characteristics of the mainstream laser ranging technology scheme,and propose an improved design scheme.Combined with the practical application requirements,the pulsed laser ranging is chosen as the distance detection method of the system,which cancels the design of the beam splitter in the traditional pulsed laser ranging system,simplifies the system circuit structure,and reduces the system hardware cost.(2)Design the laser transmitting circuit and receiving circuit.The SPLPL90＿3 laser diode is selected as the laser source of the system,and the narrow-band pulse laser driving circuit is designed;the AD500-8 avalanche photodiode is selected as the photodetector of the system,and the laser echo receiving circuit is designed.Complete the system power circuit design,and adapt the optical lens for the system according to the optical principle.(3)Design the software and hardware of the time interval measurement module.Select STM32F103ZET6 as the system controller,select the high-precision time-to-digital conversion chip TDC-GP22 as the timer,complete the hardware circuit design and system PCB design of the time interval measurement system;design the system software to realize the measurement of the laser flight time interval,and in the The Visual Studio 2015 platform development system host computer interface is used to display and save experimental data.(4)Build a laser ranging system platform for experimental verification.Perform hardware testing and functional verification on each module of the system prototype,carry out multiple sets of calibration experiments to complete the system distance calibration,verify the system measurement stability,use the Kalman filter algorithm to reduce the system measurement error,and study and analyze the experimental results.The experimental verification shows that the maximum range of the pulsed laser ranging system designed in this subject is 25 m,and the measurement error does not exceed 30 mm. |
