基于小波和可编程逻辑阵列的爆震控制

为提高汽油机爆震检测和控制精度,将离散小波变换算法和基于FPGA(Field-Program-mable Gate Array)的数字信号处理技术应用于爆震控制中.利用离散小波变换从汽油机的振动信号中提取出了轻微爆震特征,提出一种根据小波子带信号相对能量大小来评价爆震强度的指标和一种基于爆震反馈的点火提前角的控制策略.建立了基于小波算法的爆震控制模型,并进行了仿真实验验证,且将该模型在FPGA硬件上实现.结果表明:基于小波和FPGA的爆震控制方法能准确诊断出爆震,且适合于实时控制,能使汽油机在轻微爆震区工作,有利于提高汽油机的性能.

Knock Control Based on Discrete Wavelet Transform and FPGA

To increase the accuracy of knock detect and control of gasoline engine, discrete wavelet transform(DWT) and Field Programmable Gate Array(FPGA) were applied to knock control. Knock edge feature was extracted from vibration signal by using DWT. A parameter of relative energy for knock intensity evaluation, and a knock feedback ignition control strategy were proposed. The knock control model was established, verified by simulink test, and actualized on FPGA. The results show that the knock control method based on DWT and FPGA can diagnose knock accurately, is suitable for realtime control, and can make gasoline engine work at slight knock area, which is useful for improving the performance of gasoline engines.