On characteristic modeling of a class of flight vehicles’ attitude dynamics

The characteristic modeling problem of flight vehicles’ attitude dynamics is considered in this paper. In terms of the affine nonlinear system with triangle form of flight vehicles’ attitude dynamics, a general method is presented to compress the dynamics into the characteristic model parameters, by introducing the time scale of nonlinear systems and a class of system states related compress functions. The parameter region and limit of the characteristic model are also given. From the given parameter region it is seen that the bound of the characteristic model parameters is dependent on the sampling period, the modeling error, the system order and the system change rate. The modeling error of the established characteristic model can be arbitrarily small according to the control precision, showing the difference between the characteristic model and other model reduction methods, that is, no system information is lost using this approach. On the basis of this modeling approach, the characteristic model of the flexible satellite attitude is established, as well as the bound and limit of the parameters, which sets a theoretical foundation for characteristic model based control design of flight vehicles.