提出了系统存在未知输入时实现鲁棒故障检测的一种新方法。该方法以系统发生故障之前总有一段正常运行阶段的假设为前提,其基本思想是,在正常运行阶段用一般的观测器估计未知输入,估计稳定后把估计所得到的未知输入当作已知输入修正检测滤波器,这样可以避免以往的未知输入观测器方法丢失故障信息的缺点。 A new method to realize robust fault detection in the presence of unknown input is proposed. This method takes the assumption that there is always a normal operation phase before the system failure. The basic idea is to use an ordinary observer to estimate the unknown input during normal operation. After the estimation is stable, the unknown input from the estimation is regarded as known Enter the modified detection filter so that you can avoid the drawbacks of past unknown input observer methods losing fault information.