Research On The Combined Receiver Technology Of Laser Scanning Laser Scanning Large Space Positonging System

Laser scanning positioning is a new measurement technology combined with optical,mechanical and electrical disciplines,has the advantages of flexible base station arrangement,extensible measurement range and multi-position parallel measurement in space,can be applied to aircraft fuselage docking,shipbuilding,Bridges and other large parts in the assembly process,has wide application prospect.However,the existing laser scanning positioning system has realized the positioning of the center of the sensor of the front-end planar type receiver,which has high requirements for the laser signal,and cannot be used for the location of contact points such as grooves and internal cavities.On the basis of scanning measurement,this paper proposes a multi-feature point constrained combined measurement method,and designs a prototype of the front-end combined receiver to achieve the measurement of the touch point position of the probe.The paper establish a multi-feature point combined measurement model,use SolidWorks 3D modeling and MATLAB simulation to analyze the influence of the number of sensor nodes on the measurement accuracy,and complete the design of the combined receiver mechanical structure.Designed a high-speed photoelectric signal acquisition and data processing hardware system based on Zynq-7020,completed the multi-channel signal acquisition and transmission logic modeling in Zynq-7020 PL(Program Logic),realized the multiple sensors synchronous acquisition of the combined receiver.The speed reached 100Mhz.Then built a embedded system on Zynq-7020 chip,and completed the design of the control,calculation and communication system of the combined receiver in Zynq-7020 PS(Processing System).The paper proposes an algorithm based on the single-cycle signal to calculate the characteristic angle,which reduces the need for system calculation Characteristic signals improve the speed of system measurement,to sol ve the problems of poor measurement system dynamic characteristics caused by the long acquisition time and slow calculation speed.In order to improve the measurement accuracy of the system,the paper uses a combined receiver structural parameter calibration method,rotates the receiver with the cone calibration table vertex as the spherical center,builds a multi-position vector cone calibration model,and establishes a parameter nonlinear optimization solution based on the Levenberg-Marquardt algorithm Model to ensure the accuracy of system structure parametersThrough the laser scanning measurement system experimental platform,the paper carried out the verification of the measurement accuracy of the combined receiver.The verification results show that within 20m,the combined receiver hardware system can reliably complete the collection,communication and display of photoelectric signals.The algorithm based on the single-cycle signal to solve the characteristic angle can accurately solve the system characteristic angle.With this algorithm,the measurement speed of the combined receiver can reach 13Hz.The combined receiver can realize the measurement of the contact point of the probe.The measurement results of the distance accuracy at each location point prove that the accuracy of the combined receiver can reach±0.3mm.