| A kind of large-stroke,high-precision positioning platform is needed in some high-tech fields,such as integrated circuit manufacturing,precision mechanical assembly,fine cell operations,and ultra-precision measurement.To some extent,there exists some related problems in the traditional positioning platforms.For example,mechanical friction,poor positioning accuracy,and limited positioning range.The maglev positioning platform supported by maglev force is proposed and considered as an effective device for high-precision positioning.Therefore,carrying out detailed research on the maglev positioning platform has a great application value.The thesis projects the overall structure of the maglev positioning platform adopting "linear motor + maglev technology".The vertical levitation force and the horizontal driving force that drived by the movement of the levitation positioning platform are generated by the interaction between the permanent magnets and the stator windings of the HALBACH permanent magnet synchronous linear motor,which realizes levitation and positioning movement of the positioning platform.Theoretical analysis method and finite element simulation method are used to simulate and analyze the electromagnetic force of HALBACH permanent magnet array and permanent magnet synchronous linear motor.The well unilateral characteristics of HALBACH permanent magnet array are verified and the relevant electromagnetic force parameters are obtained.In addition,the dynamics model of the positioning platform is established.The decoupling control in the vertical and horizontal directions of the positioning platform is realized by using DQ decoupling and the Taylor series expansion approximate linearization for the strong coupling and nonlinear characteristics of the positioning platform.Then the overall structure of the hardware and program design of the maglev positioning platform control system is determined.Among them,FPGA is taken as the core of the external drive program design.Regarding to the control algorithm is complex,a controller based on MicroBlaze soft core is constructed to achieve the decoupling of the positioning platform and the position loop and current loop dual loop PID control.Because of the low power of the maglev positioning platform and the high requirement for accuracy,a linear amplifier circuit is used to design the positioning platform driving system.At the same time,the relevant sensors are selected and the signal acquisition circuit are designed.The parameters of the relevant devices are determined and the performance of the sensors are verified.Finally,the Simulink simulation model of the maglev positioning platform control system and the experimental system of the maglev positioning platform are built.The relevant simulation and positioning experiments are carried out to verify the excellent control effect of the control system and the fantastic performance of the hardware and software of the designed maglev positioning platform. |
