Analysis And Control Simulation Of 2T2R Hybrid Parallel Robot

Through the analysis of the working requirements of spine surgery aids,a plan that positioning and orientation separately was presented.Select the mechanisms that meets the requirements according to the two-part plan and form the final design plan.Taking the two parts of the mechanism as the research object,the main work of this thesis is as follows:Firstly,analysis the number of DOF that spine surgery aids requires,reasonably configure the DOF of positioning and adjustment mechanism,select 5R parallel mechanism as positioning mechanism and RRRUS mechanism as posture adjustment mechanism.A hybrid 2T2 R robot scheme that ultimately applies to the auxiliary operation of spinal minimally invasive surgery.Calculate the overall degree of freedom by applying spin theory,mechanism order,splitting principle and modified freedom formula.Then,solving forward and inverse kinematic solution models of positioning mechanism and attitude adjusting mechanism based on geometric relations and vector equations,the mathematical model was used to solve the four inverse decomposing positions and two positive decomposing positions of the positioning mechanism and the four inverse decomposing positions and two positive decomposing positions in the position adjusting mechanism,and which position type the mechanism moves to depends on the initial position type.Based on the position relation,the closed-loop vector differential method is used to solve the error model of the pose adjustment mechanism.Orthogonal design method was used to analyze the response of attitude to each error source,and several error factors that affected the error were obtained.Then,the dynamics of the two parts of the mechanism were analyzed using the Lagrange method.The function relationship between passive joint speed and active joint is obtained by the derivative equation of positional relationship.The time-varying moment of inertia was deduced using the formula of the inertial matrix rotation,and the rotational kinetic energy of the space-moving rod was solved.Using the cycloid motion and cubic polynomial to plan the motion trajectories of the two parts respectively to verify the correctness of the mathematical kinetic modelFinally,the control method founded on the dynamic model was analyzed.The ADAMS dynamic model of the pose adjustment mechanism was imported into simulink.Using the control method of separating the servo loop and the model loop,using the ADAMS/simulink co-simulation technology.The dynamic control simulation experiment was performed on the attitude adjustment mechanism;The simulation achieves the tracking of the active joints under the planned trajectory.