The 3D Point Positon Measurement System Development And Precision Control Method Research

Non-contact measuring device has important engineering application value in coal mine underground detection,indoor fire alarm rescue and indoor anti-terrorism.At present,the application of domestic automatic and semi-automatic laser range finder is not very ideal,and the accuracy is the key factor restricting its practical application and development to high-end.In this paper,a non-contact measuring device based on manual operation and laser ranging is developed,which is funded by Shenyang Fire Research Institute of the Ministry of Public Security,the error model is established and the precision analysis is carried out.Finally,the method of precision synthesis of the device is proposed by using genetic algorithm and cost tolerance model.The research work in this paper has important reference significance for the development,accuracy analysis and synthesis of other measuring devices.The main contents of the paper include:(1)A passive laser measuring system is designed to meet the requirements of view angle,obstacle avoidance and fast playback for the large-scale non-contact measuring case task of indoor fire fighting and rescue.the configuration and structure design of the main arm of the device are completed,and the first prototype is manufactured.On this basis,the kinematics model of the measuring device is established by using D-H method,and the kinematics simulation and workspace simulation are carried out by using MATLAB,which proves the rationality and correctness of the design.(2)Depending on industrial sensors,the acquisition and communication of mechanicaloptical-electrical signals in the measuring device system are conquered,and the real-time measurement of the distance and angle data of the device is realized.Visual Basic software is used to realize the communication transmission between the above data and the host computer.Based on the homogeneous coordinate transformation,the theoretical algorithm of spatial point position and attitude is deduced.Finally,the real-time online display of measurement results of spatial point position and attitude is realized.(3)The more accurate MDH method is used to re-model the measuring device,and then the geometric error model of the measuring device is established based on the differential method to provide the basis for accuracy analysis.The static error of the device is analyzed,the random error of the device is analyzed by Monte Carlo method in MATLAB,and the sensitivity information of each joint size is analyzed,which provides reference information for precision synthesis.(4)The application method and steps of genetic algorithm are defined,and a cost tolerance model based on processing characteristics is established according to the actual processing situation of the measuring device.The genetic algorithm is used to optimize the detection device with tolerance cost as the optimization objective and detection accuracy as the constraint condition.The optimal tolerance allocation scheme satisfying the constraint is obtained,and the accuracy synthesis of the measurement device is completed.