Design And Implement Of Digital FIR Filter For Gap Signal Of High Speed Maglev Vehicle

As a novel transportation vehicle,high-speed maglev train is gradually applied in Urban Rail Transit System because of its speediness,safety,comfort and low noise.Suspend control system is the core of high-speed maglev vehicle while gap sensor is a critical part of the system.The gap sigal measured by gap sensors is pivotal to the control system.Correct control depends on accurat,stable and reliable gap signal.However,the gap sensor works in a complex electromagnetism site in which the signal is disturbed by undesired yawp.So the signal must be processed in order to be suit for the system.At present,the normal process uses the IIR filter integrited in the DSP controller which has some deficiencies.Thus,a digital filter is proposed based on FPGA in view of the features of the sensor signal,and is tested on the platform of gan sensor.Firstly,considering the advantages of FIR fitlter,a linear phase struture is choosen to implement the filter.Parameters and frequency characteristic are designed by Matlab,and the result is simulated using Simulink.A new predictive algorithm is adored against the strong impulsive noise.This methods are validated by simulation and expetiment respectively.Secondly,an approach of hardware realization is worked out using distributed arithmetic(DA)based on FPGA.As LUT scale of the DA is too large, the design reduces it with multiple look-up tables.A sixteen-tapped lowpass FIR filter soft module is described by verilog-HDL,and is synthetized by ISE9.1 and Midelsim.The synthesis and simuliation demonstrate that the filter has high response speed and low hardware consumption.Meanwhile,the frame indicates flexibility at realizing the low-pass,high-pass and band-pass filter easily just with the modifications on FIR filter LUT respectively.Finally,the hardware testing plateau is founded.The niose from the gap sensor is dealed with via the plateau.And the result is well meet the system requirements.