Research On The Micro-Positioning Platform Based On Distribution Flexible Type Planar Compliant Mechanism

Precision positioning technology is the strategic choice to enhance the national core competitiveness and comprehensive national strength,and the control system design of micro-positioning platform is the key part of the precision positioning technology.The distribution flexible type planar compliant mechanism is a new micro-positioning mechanism,which not only has the compliant mechanism’s advantages of free assembly lubrication,no friction and wear,no movement gap,but also has the parallel mechanism’s characteristics of strong bearing capacity,multi dimension movement and good stability.The micro-positioning platform based on distribution flexible type planar compliant mechanism has high movement precision,large stroke,fast dynamic response and small size,and it can achieve submicron-positioning accuracy and nanometer resolution.Therefore,the distribution flexible type planar compliant mechanism can widely use in micro/nano manufacturing,micro-electronic technology,precision engineering and other frontier fields,its motion characteristics analysis and control system design have become the focus of domestic and foreign scholars.In this paper,the research object of distribution flexible type planar compliant mechanism is studied.The kinematics and dynamics characteristics of mechanism were mainly discussed,the mechanism controller is designed and control system is established.Finally,the correctness of theoretical analysis and the mechanism’s model were verified through the experiment.The specific research contents are as follows:(1)The micro-kinematics of distribution flexible type planar compliant mechanism was analyzed by the micro-displacement method based on the vector isomorphism model of mechanism,so the Jacobian matrix of mechanism is obtained.The displacement/rotation and stress cloud contour of mechanism are obtained by means of simulation,and the motion characteristics of mechanism and the effectiveness of Jacobian matrix are verified.(2)The rigid body dynamics model of mechanism is established by using Lagrange equation.Based on the beam element model and the principle of dynamic elastic dynamics(KED method),the elastic dynamic model of mechanism is established.On this basis,the modal dynamics characteristic of mechanism is analyzed,and the three order natural frequencies and mode shapes of mechanism are obtained.Therefore,the effectiveness of mechanism’s dynamics model is verified.(3)The sliding mode controller(SMC)is designed based on the elastic dynamics model of mechanism and the filter,and the stability of controller was proved by Lyapunov function.Based on the S-Function function and Simulink diagram,the control system of mechanism is established.The displacement trajectory tracking curve and error curve are obtained by means of simulation.(4)The experimental test of distribution flexible type planar compliant mechanism is carried out,the experimental data of mechanism output coupling,positioning accuracy and trajectory are obtained,and we compare it with the theoretical calculation value,at the same time,the causes of data error were analyzed.Therefore,the correctness of theoretical analysis was verified.