| As one of the most promising brain science technologies in the 21St century,TMS technology is a multidisciplinary cross-product.How to find stimulation targets in physiological research and how to design magnetic stimulation coils in physics have achieved many results,but its clinical application process the initial coil positioning,target offset tracking,repeat positioning accuracy,and human interference have restricted the improvement and popularization of this technology.One can summarize it as an engineering application problem.In order to solve the above problems,this thesis proposes a transcranial magnetic therapy system solution based on a parallel robot.Combined with parallel robot technology,image processing technology,and medical imaging technology,a magnetic stimulation coil positioning strategy is given,and the key technology of the parallel robot is to design the mechanism and structure.Moreover,the posture error,structural parameter optimization and trajectory planning of the TMS parallel robot are studied.The detailed work is as follows:1.Atranscranial magnetic therapy system based on a parallel robot is proposed.The combination of a 6-UPS parallel mechanism and a two-degree-of-freedom head is used to resolve the contradiction between the small working space of the parallel mechanism and the large attitude space required for TMS treatment on the premise of taking full advantage of the parallel mechanism.Further,the position analysis of the two-degree-of-freedom head is carried out,and the kinematics model of the 6-UPS parallel mechanism is established,and the important kinematic performance parameters such as the forward position solution,the inverse solution,the working space,and the Jacobian matrix are analyzed.2.The pose error model of TMS parallel robot was established.The single-chain error model method was used to derive the mapping relationship between the structural parameters of the 6-UPS parallel mechanism and the posture error of the moving platform.The structural parameter error and pose accuracy were further analyzed.At the same time,the correctness of the pose error model was verified by numerical simulation software,and the influence of structural parameter changes and pose parameter changes on the pose error of the moving platform was simulated.Provide guidance for later manufacturing,structural parameter selection,and traj ectory planning which lays the theoretical foundation.3.The multi-objective optimization design of the structural parameters of the TMS parallel robot was carried out.A multi-objective function was established using the weighted factor method with the average Jacobian matrix condition number and the electric cylinder leg length limit.An improved differential evolution algorithm based on adaptive mutation was proposed and compared with the standard differential evolution algorithm to verify the adaptive the validity of mutation operators.For the optimized mechanism,the polar coordinate search method is used to solve its working space,and the accuracy of the posture of the moving platform after optimization is compared with that before optimization.The results show that the accuracy of the optimized mechanism is improved and the kinematics performance is better.4.The trajectory planning and dynamics simulation of TMS parallel robots were conducted.Firstly,Fifth-order polynomial is used for trajectory planning,and the coil positioning time is optimally solved,and the kinematic parameters of the mechanism during the typical movement of the coil are analyzed.Secondly,based on Lagrange’s equation,its dynamic model is established,and the relationship between generalized pose and generalized force is derived.Finally,the kinematic parameters of the mechanism during the movement of the coil are analyzed,the formula for calculating the driving force of the mechanism is derived,and the dynamics of the mechanism during the movement are simulated and analyzed,which clears the technical obstacles for practical applications. |
PDF Full Text Request