摘要：Increasing the robustness to the unknown uncertainty and simultaneously enhancing the sensibility to the faults is one of the important issues considered in the fault detection development. Considering the L2-gain of residual system, this paper deals the observer-based fault detection problem. By using of H∞ control theory,an LMI approach to design fault detection observer is given. A numerical example is used to illustrate the effectiveness of the proposed approach.

摘要：This paper presents a detection method for hourglass worm based on follow-up pre-positioning technolo-gy, by establishing theoretical model of the corresponding relation between the movements of the worm and theprobe. The probe coordinate of next sample point is mapped through the actual motion coordinate measured ateach sample point. And then the probe is located to the next sample point in advance by using the precision mo-tion control based on time subdivision. This detection method can realize online servo measurement for machiningerror of hourglass worm and actual space spiral measurement under specific throat radius. The actual surface con-tour of hourglass worm is constructed by helixes in different throat radiuses, then the machining error can be ob-tained by comparing the contour with theoretical model. The detection system, which includes host and slave sub-systems, is designed according to this method.