Design And Control Of Multi-degree-of-freedom Composite Platform With Vibration Isolation And Leveling Ability Based On Quasi-zero Stiffness Principle

With the development of microelectronic manufacturing equipment towards precision and intelligence,the requirements for high-precision visual inspection technology are higher and higher.The vibration caused by equipment movement and environmental interference and the non-level problem of the measured workpiece will cause image blur and even lead to detection failure.Therefore,precision vision detection systems demand strict requirements for vibration isolation and leveling performance of the workpiece platform.Aiming at improving of platform performance for visual inspection system,this thesis studies the vibration isolation and leveling control technology of the workpiece platform,and proposes a new miniaturized mechanical structure of composite platform with vibration isolation and leveling ability.Based on the dynamic modeling and simulation analysis of the platform,a two-axis leveling control algorithm,an active vibration reduction control algorithm,and a multi-degree-of-freedom cooperative control method of the platform are proposed.The vibration isolation and leveling performance of the designed composite platform is verified by building the experimental system of vibration isolation and leveling composite platform.The main research contents of this thesis are summarized as follows:1.Investigate the research status of active vibration isolation technology,directional leveling technology,and vibration isolation and directional composite technology.Compare the advantages and disadvantages of the current research,and clarify the difficulties and key technologies of vibration isolation and leveling coordination.Clarify the technical route and research content of this thesis.2.The principles,characteristics and limitations of the classical isolation theory and quasi-zero stiffness isolation theory are studied and analyzed.Based on the theoretical analysis of quasi-zero stiffness isolation,the theoretical model of bi-stable buckling beam negative stiffness mechanism is deduced.The realization principle and characteristics of the negative stiffness mechanism are clarified,and the negative stiffness model required for the design of vibration isolation platform is obtained;3.A new structure of composite platform with vibration isolation and leveling ability is designed.Through the component design,calculation,modeling and simulation analysis of the composite platform,the structural parameters and selection of the composite platform and key components are determined.Through the finite element simulation analysis of the overall structure of the composite platform,the static and dynamic characteristics of the composite platform are verified.4.Aiming at the leveling control and vibration reduction of the composite platform,the double axis leveling PID control algorithm of the composite platform is proposed to realize high-precision and fast leveling;Based on the positive position feedback（PPF）control method,the active vibration reduction algorithm of the composite platform is designed to suppress the resonance peak of the platform and improve the vibration isolation performance of the platform.Through the coordinated control method of vibration isolation and leveling of the platform,the coordinated control of vibration isolation and leveling of the platform is realized;Finally,the control system of the platform is simulated and analyzed by using Adams-simulink joint simulation system to verify the feasibility of the proposed control algorithm.5.Establish the designed vibration isolation and leveling composite platform experimental system,and carry out experiments of the composite platform on vibration isolation performance and leveling performance,as well as cooperative working performance of vibration isolation and leveling.The feasibility and effectiveness of the designed vibration isolation and leveling composite platform are validated.