Missile LFT model and its application in H_∞ gain-scheduled autopilot design

The missile linear fractional transformation (LFT) model was established by the graph approach, and the missile's dynamics was separated into certainty part and uncertainty part. Based on the LFT model, the linear parameter varying (LPV)/μ control structure was established, and the H_∞ gain-scheduled autopilot was designed by use of D-K-D iteration. The designed controller with the LPV/μ technique, which takes account of the time-varying nature of missile explicitly, can automatically gain-schedule the parameters in the course of missile flight, adapt to the variation of the missile dynamics characteristics, and stabilize autopilot dynamics characteristics over its entire operation range. Simulation results show that the LFT model can describe the missile's dynamics exactly, and the dynamics of H_∞ gain-scheduled autopilot are independent of the flight conditions.