Design And Simulation Of Laser Ranging System Based On Phase Method

As a measurement technology,laser ranging,compared with other measurement methods,is widely used in many fields because of its unique advantages such as non-contact,fast measuring speed,high measuring accuracy,long measuring distance and strong anti-interference ability.In the field of intelligent transportation,such as automobile collision avoidance system and driverless car,the function of road safety identification is realized by laser ranging sensor installed on the vehicle.The application of laser ranging technology plays a major role in road traffic safety..In view of the domestic laser ranging measurement accuracy is not high,complex design and other problems,this paper analyzes the factors affecting the accuracy of the laser ranging system from a variety of angles,in order to improve the system measurement accuracy,simplify the system circuit structure,reduce the system design cost as the goal,design a laser ranging system based on phase method.A laser ranging system based on phase method is built on the theory of phase ranging and phase difference frequency measurement.In the clock generation module,the LMK04000 clock generation circuit based on CPLD control is designed.The influence of clock phase noise on the measurement system error and the influence of harmonics on the system measurement in the clock signal are analyzed.A simplified clock circuit design scheme is proposed.By analyzing the noise of photodiode amplification circuit and the influence factors of the optimal detectable distance of the system,the photodiode amplification circuit is optimized and the total output noise of the circuit is reduced.Improved the laser drive circuit,improve the output power of the drive circuit.The circuit of the difference frequency output module is designed to reduce the frequency of the high frequency signal to the low frequency signal.On the basis of the completion of the system circuit design,the circuit of each module is simulated.Through the simulation results,we can know that each module circuit can achieve its corresponding function,and verify the feasibility of the system.The phase-based laser ranging system designed in this paper has basically met the design requirements.