Accuracy Analysis Of The Selective Compliance Assembly Robot ARM

Accuracy is one of the significant indexes to evaluate the performance of industrial robots,which is key to their execution work.China's research about industrial robots started late,there is a big gap comparing with foreign countries in the accuracy design aspect.Therefore,it has an important significance to study the factors affecting motion accuracy of robots and analyze the influence mode of different error sources.This paper takes a type of SCARA industrial robot as the research object,analyzes the relationship between the end of the robot's motion accuracy and the error sources.The main contents are as follows:In order to describe relationship between joint's output position and pose and the input position and pose,a homogeneous transform equation was built based on D-H coordinate system.Then compared with the simulation results,the correctness of the kinematic equation was verified.An error model was built on the basis of the joints displacements considering all kinds of errors.It laid a foundation for further accuracy analysis.In order to find out the relationship between structural parameters and the motion accuracy,in a fixed position,conducted the separate analysis of each structure parameters,found that the structure parameters only affected position accuracy,and no effect on the pose accuracy.In order to find the relationship between position parameters and accuracy,conducted a conjoint analysis for the main parameters,found that only the position parameters of the target joint had influence on the end accuracy.In order to analyze the influence of structural deformation on the end accuracy caused by,used virtual prototype to simulate.Through analyzing the deviation of the theoretical position and the actual position of the motion end,I found that the structure deformation's influences on the accuracy when it was in no-loaded state was obviously different from loaded state.In order to solve the accuracy decline problem due to the structural deformation,I carried out the real-time error compensation based on the trajectory planning.The simulation results shows that the error compensation method of trajectory planning is an effective method for improving the operation accuracy of robot.