Optimal Design And Control Strategy Of Controllable Surgical Instrument Arm

With the continuous development and progress of science and technology,people pay more and more attention to their physical health.Medical surgical instruments have also developed rapidly.In minimally invasive surgery,rigid surgical instruments have poor flexibility due to their structural characteristics.Prolonged surgical operations can cause fatigue and jitter in doctors.In this paper,in view of the shortcomings of rigid surgical instruments such as poor flexibility and limited movement space,a controllable continuous surgical instrument arm is studied.The surgical instrument arm uses the super-elastic properties of the nickel-titanium alloy material,which can make it have a larger operating space and a higher operating flexibility.First,based on the analysis of the existing continuous surgical instrument arm configuration,the structural configuration of the controllable surgical instrument selected in this paper is proposed.The thesis uses 3D modeling software and finite element analysis technology to design the geometric structure of the manipulator.Then on this basis,the geometric design of the robot arm is optimized to improve the material utilization rate of the robot arm and the ability of the end to resist external loads.Secondly,a kinematic model is established for the geometric model finally selected in the paper.Because the geometric structure selected in this paper is compliant,it does not have traditional rigid joints.The D-H parameter method cannot be used to establish the kinematic model,and the mathematical analysis method is finally used to establish the constant curvature kinematic model.The motion space of the robotic arm is obtained through simulation,and on this basis,an improvement scheme for increasing the operating space of the robotic arm is proposed.Finally,the theoretical trajectory of the kinematic model and the trajectory obtained by simulation are compared and verified.Thus,the correctness of the kinematic model of the robot arm was verified.The ability of the manipulator to resist the external load by analyzing the external load at the end of the manipulator is analyzed.Finally,based on the kinematic model established by the configuration,the control strategy of the mechanism was studied.And finally decided to use the position feedback control method to control the structure.By adopting the position feedback control method,the structure can have higher end positioning accuracy.