Gas flow regulation system is crucial to the performance of the ducted rocket. However, in previous studies, only the gas pressure is taken as the input of the controller, thereby ignoring the characteristic that this system is a non-minimum phase system. To overcome this limitation, a gas flow regulation method based on universal tracking controller was designed. The simulation results show that for the square wave command where the gas generator pressure command is adjusted between 5 and 9 MPa, compared with the TD-PID controller, since in addition to gas pressure, the internal state (i.e., the angle of the slide valve) is also taken as the input of the controller, this method not only transforms the gas flow regulation system into an approximately linear time-invariant system, but also significantly enhances the control performance, verifying its effectiveness. Furthermore, comparison of different time lag constants and step disturbance amplitudes on the response curves reveals that although there are situations where the response of slide valve under high pressure is slow or the particle deposition causes a sudden change of the throat area, the controller can still maintain good control performance.
Wang et al. (Thu,) studied this question.