Adaptive notch filter design for bending vibration of a sounding rocket

An adaptive notch filter design considering the body bending vibration for the attitude control of a two-stage sounding rocket is discussed in this pa per. The algorithm adapts the parameter while keeping the poles of the notc h filter inside the unit circle on the z plane, and thus satisfies the cond itions concerning stability of the filter all the time. Only a single param eter of the filter is adapted to simplify the algorithm and thus to speed u p the convergence rate. Applying this adaptive notch filter to the two-stag e sounding rocket results in stable response characteristics of the attitud e control system which has been unstable without adaptation. This newly des igned method is simple and less CPU intensive, and is easier to implement i n real-time application.