Design And Actuation Of A Long Stroke Air-levitated And Magnet-driven Nanopositioning Stage

Nano-machining,laser direct-writing technology,processing and measurement of aspheric optical instrument and lithography used for chip manufacturing put forward higher and higher requirements for performance of the positioning platform: nano-scale positioning accuracy in the large travel range.The traditional precision positioning platform using flexible hinge combined with piezoelectric actuator gets the nanopositioning accuracy,but its travel range is only tens of microns to hundreds of microns.For the macro-micro combined platform,the macro motion is driven by the traditional servo motor,the micro motion is still acutated by the piezoelectric actuator,thus ensuring the large travel range and precision positioning,but the structure of platform is very complex and the controller involving macro-micro motion control switching is sophisticated.In order to solve the above problems,this paper proposes an air-levitated magnet-driven nanopositioning stage,designs and manufactures the mechanical body of the positioning stage,builds a three degree-of-freedom drive system of positioning stage,establishes the dynamics model of positioning stage,designs the positioning stage controller and carries on the experimental verification.Firstly,the three degree-of-freedom nanopositioning stage is designed with three magnet-driven units as the driving element and the air-levitated guiding mechanism to realize three degree-of-freedom motion in the X direction,the Y direction and the Z rotation.The finite element model of the moving parts of the positioning stage is established,and the structure of the moving stage is optimized considering the modal frequency and weight.Secondly,build a three degree-of-freedom nanopositioning stage drive system.The design of multi-channel data acquisition card based on PCI9054 bridge chip and FPAG chip is adopted.The xPC-Target real-time system in Matlab / Simulink is used as the core to build the hardware in loop simulation of nanopositioning stage.Verify the feasibility of the nanopositioning drive system.Finally,the dynamic modeling and control of the nanopositioning stage are carried out.Complete the three degree-of-freedom nanopositioning stage force distribution.On this basis,an experiment apparatus is set up.A PID controller and a PID controller based on the disturbance observer are designed.To complete the point-to-point motion of the nanopositioning stage,the feasibility of the nano-scale positioning resolution of the stage in large travel is verified.