Error Research And Mechanical Property Analysis Of Parallel Mechanism For Cervical Traction Rehabilitation Based On 2-UPR+RPS

This paper is based on the cervical vertebra traction rehabilitation mechanism of 2-UPR+RPS parallel mechanism to carry out error research and mechanical property analysis.Reduce the posture error of the moving platform of the rehabilitation mechanism through error modeling,error analysis and error compensation;through static analysis to ensure that the elastic deformation of the parallel mechanism under the condition of external force does not affect the motion accuracy of the rehabilitation mechanism;through dynamic analysis to ensure the human body The cervical spine can withstand the driving force of the rehabilitation mechanism.This article mainly discusses the following aspects:1.Classify the error of the 2-UPR+RPS cervical traction rehabilitation mechanism,the closed vector method is used to model the error,and obtain the error Jacobian matrix of the parallel mechanism,which can map the position and attitude error of the moving platform and the error source relationship.According to the established error mathematical model,the global error sensitivity of the parallel mechanism is analyzed,and important errors and unimportant errors are found.In the case of ignoring unimportant errors,Matlab is used to analyze the global pose error and local pose error of the parallel mechanism,and the correctness is verified by the Adams parameterized virtual prototype experiment,and the local pose error that needs to be compensated is obtained.By controlling the dimensional error and assembly error of the parts of the parallel mechanism,the particle swarm algorithm is used to compensate the error of the rehabilitation mechanism.A set of optimal solutions is selected for the analysis of the calculation examples,and the results show that the global pose error and local pose of the moving platform of the mechanism are significantly reduced,which can meet the requirements of cervical traction rehabilitation.2.Perform statics and static stiffness analysis of 2-UPR+RPS cervical vertebra traction rehabilitation mechanism.The static analysis of the parallel mechanism is carried out by using the method of dismantling the rod,and the static stiffness analysis is carried out according to the results of the static analysis,and the static stiffness matrix of the mechanism is established.Matlab is used to analyze the static stiffness distribution of the parallel mechanism,and Ansys is used to conduct virtual prototype experiments on various working conditions of the parallel mechanism to verify the static stiffness distribution of the parallel mechanism.The results show that the deformation of the parallel mechanism under the condition of external force is negligible,and the static stiffness meets the requirements of use and does not affect the accuracy of use.3.According to the maximum external force that the human cervical spine can withstand,a dynamic analysis of the 2-UPR+RPS cervical traction rehabilitation mechanism is carried out.The virtual work principle method is used to model the dynamics of the parallel mechanism,and Adams is used to analyze the dynamics of the virtual prototype of the parallel mechanism.According to the analysis results of the Adams virtual prototype,the value range of the driving force of each branch chain driver under different working conditions is determined.This is of great value to the application of cervical traction rehabilitation mechanism.