Research On A Three Dimensional Position Detecting Device And Its Application To Serial Robot Calibration

With the rapid development of industry,manufacturing and other fields,the research and production of all kinds of equipment are in urgent need of advanced detection technology.In the field of detection technology,three dimensional position detection technology plays an important role.It's based on the mechanical structure and integrates many technologies.Three dimensional position coordinates of the objects are obtained by the detection equipment,and then a variety of measurement functions are realized.In this paper,a new type of three dimensional position detection device is developed,and use it to measure the end position of the laboratory's laparoscopic minimally invasive surgical series robot.On this basis,the robot kinematics model parameter calibration and measurement of movement characteristics are studied.In order to meet the requirement of high precision and low cost at the same time,the overall design scheme of three dimensional position detection device based on a draw-wire sensors is proposed.By considering minimizing the influence of complex machining and assembly errors,a simplified mechanism consisting mainly of over-wire block and back-up block is designed.Two kinds of position coordinate mathematical models are established by the method of Spatial Analytic Geometry and Helen Theorem,and the solving method of the nonlinear equations is determined.Then the measuring space of the detection device is analyzed.The device components are selected,and the hardware platform is built.On this basis,the LabVIEW software is used to write a variety of measuring functional programs and provide a good human-computer interface for the users.Taking the measure real-time as a starting point,the mathematical model of the detection device is determined.Through the experiment,the error analysis of the detection device is carried out,and the mechanism and precision test method are improved to improve its measurement accuracy.Based on the mathematical model of position coordinate,the error model of device structure parameters is established.The self calibration experiment is designed,and the parameter error identification and mathematical model correction work are completed.The measurement accuracy of the device before and after calibration is compared,and the relative error of the device is reduced to 0.5307% by self calibration.Finally,the comparison experiment of measuring precision of different layout detection devices is carried out to verify the superiority of the four way draw-wire sensors layout.The feasibility and key problems of the three dimensional position detection device for the kinematic calibration of a laparoscopic minimally invasive surgical series robot are analyzed.Based on the forward robot kinematics model,the absolute error model and the distance error model are established,and the correctness of the models is verified by MATLAB.The method of motion compensation after robot calibration is studied to provide a compensation strategy for accurate motion.The incidental force of the detection device is studied,and the experimental method is designed to identify the relationship between the force and the elongation of the draw-wire sensors.In order to display the force of the measured object in real time,the model of the incidental force is established,and the possible influence of the force is analyzed.The experimental platform of robotic kinematics calibration is built,and the kinematic model was corrected by the experimental results,and the motion accuracy of the robot is obviously improved.The dynamic measurement function of the device is designed,and the experiment of measuring the distance,speed and acceleration of the robot is carried out to test the feasibility of the function.