基于FPGA的双轴倾角计信号提取方法研究

RESEARCH ON DUAL-AXIS INCLINOMETER SIGNAL EXTRACTION METHOD BASED ON FPGA

为从车辆复杂噪声背景下实时提取双轴倾角计的有效信号,在分析弱信号特征提取方法的基础上,针对LMS算法在处理相关信号时收敛速度降低的缺点,提出一种对噪声敏感度较低的变步长LMS算法,基于FPGA平台设计实现一种采用一阶滤波单元重用方式实现多阶LMS滤波器的可扩展滤波器结构。试验首先通过收敛速度评价指标验证算法的优越性;其次利用滤波后的双轴倾角计信号的频谱分析证明算法对其自身噪声与车载环境噪声有较好抑制;最后对比5种不同硬件平台实现结果的差异,试验表明FPGA实现方案在执行时间、功耗和硬件占用率方面具有明显的优势。

In order to obtain the effective signal of dual-axis inclinometer from complex automotive noisy environment timely and to solve the problem of convergence speed drop the least mean square（LMS） algorithm has while processing the relative signals,we present a variable step LMS algorithm with lower sensitivity to the noise based on analysing the weak signal extraction methods.A scalable filter structure is designed and implemented on FPGA platform,it can achieve multi-order LMS filter with single-order filter unit in the way of reusing.In the experiment,firstly,we use the index of convergence speed to attest the superiority of the algorithm.Secondly,we use spectrum analysis of the signal of dual-axis inclinometer after filtration to demonstrate the algorithm possessing quite good restraint on the noises of its own and the vehicle environment.Finally,we compare the differences of results implemented on 5 various hardware platforms.Experiment proves that the FPGA implementation scheme has obvious advantages in execution speed,power consumption and hardware utilisation rate.