Research On Trajectory Planning And Motion Control Of High-speed Drive Quick-Insertion Mechanism

In the wind tunnel heat flow measurement test,in order to improve the accuracy of the test,it is necessary to insert the test model into the center of the flow field accurately and at a high speed in a short time.For this reason,according to the design requirements of quick-insertion mechanism with fast motion process,high position accuracy and stable motion process,combined with the motion characteristics of linear motors,this paper studies the trajectory planning algorithm,trajectory parameter optimization and motion control of the high-speed drive quick-insertion mechanism.First,the common acceleration and deceleration trajectory planning algorithm and the three-stage trigonometric function acceleration and deceleration method are introduced,and a seven-stage trigonometric function acceleration and deceleration method is proposed.The results of different trigonometric function trajectory planning methods show that under the same acceleration and deceleration time,the seven-segment trigonometric function can reduce the maximum acceleration value of the acceleration and deceleration segment compared with the five-segment type,which reduces the maximum acceleration value by 7.54% and 7.07% respectively;At the same time,the seven-segment trigonometric function can shorten the total movement time compared with the three-segment,shortening by 6.06%.On this basis,with the goal of reducing the time-consuming calculation of trigonometric functions,methods such as Taylor series expansion,Chebyshev function and polynomial function are used to approximate the seven-segment trigonometric function,and the calculation time-consuming sum of the function approximation is analyzed.Error,it can be concluded that the Chebyshev function approximation can save calculation time,and the error is relatively stable,all within 4%.Secondly,using the optimal Latin hypercube experimental design method,the sensitivity of the input parameter variables to the optimization index is analyzed.According to the theory of multi-objective optimization,a high-speed drive trajectory planning optimization model is established.Through the non-dominated sorting genetic algorithm(NSGA-II),the parameters of the trajectory planning after the seven-segment trigonometric function Chebyshev function are approximated are optimized.The results show that the maximum acceleration,maximum power(acceleration section and deceleration section),and total motion time of the linear motor after optimization are reduced by 3.42%,3.21%,2.74%,11.28%,4.29%,respectively.The performance of the linear motor in the FV curve The margin is greater.Thirdly,the high-speed drive motion control method has an important influence on the stability of the motion process.The mathematical model of the linear motor is established by derivation of the linear motor d-q axis voltage equation,and the PID control method and the sliding mode variable structure control method are designed.The simulation models of two control methods are built in Simulink.The response curve and displacement error results of the simulation output show that both PID control and sliding mode control can better control the linear motor,improve the stability of motion,and the displacement of sliding mode control.The following error is small.Finally,according to the actual working conditions,a quick insertion mechanism and an electronic control system are designed and built,and a seven-segment trigonometric function trajectory planning verification experiment and a control experiment of different PID parameters are designed.Experimental results show that the seven-segment trigonometric function trajectory planning algorithm proposed in this paper can meet the requirements of fast and stable motion,and when the PID parameters are appropriate,the mechanism can be fast and stable with small errors.