火车对接测距系统中ZOOM-FFT应用研究

将ZOOM-FFT方法应用于火车对接测距系统,该系统采用FPGA+DSP双处理器模式实现对调频连续波(FMCW)雷达传感器信号的采集和处理。其中,FPGA实现对并行A/D转换芯片的控制及与DSP进行数据传输;DSP采用ZOOM-FFT算法实现测距功能并通过485总线实时输出距离。理论分析与实验结果表明,ZOOM-FFT方法有利于提高系统的处理速度和距离分辨率,且可实现小距离测量。实验室环境下,系统在0.5~10 m内绝对误差＜0.2 m,在10~50 m内的绝对误差＜0.5 m。在长沙机务段的现场试验结果表明:SS8、HXD3C和DF5型机车测距结果基本满足系统测距要求,0.5~50 m范围内测距绝对误差约0.5 m,在＞44 m时,出现最大误差为0.64 m。

Application of ZOOM-FFT in the Distance Measurement System for Train Docking

The ZOOM-FFT frequency subdivision technology was used in the distance measurement system for train docking, which adopts dual processors of DSP and FPGA to achieve FMCW radar sensor signal acquisition and processing. FPGA controls parallel A/D and transmits data with DSP by ZOOM-FFT algorithm to achieve real-time distance and outputted distance via RS 485. Theoretical analysis and laboratory experimental results indicate that the ZOOM-FFT frequency subdivision technology can improve the processing speed and the resolution of the system effec- tively, and that the system used the ZOOM-FFT can measure small distances. Under laboratory conditions, the ab- solute deviations of the distance measurement system are less than 0. 2 m in 0. 5 ~ 10 m and less than 0. 5 m in 10 - 50 m. At the Changsha locomotive depot, the experimental results show that the measure results on SS8 model and HXD3C model and DF5 model satisfy the basic distance measure requirements, which the absolute deviations about 0. 5 m in 10 ~ - 50 m and the maximum deviation is 0. 64 m when the distance over 44 m.