Research on longitudinal manipulation strategy of partial tilting aircraft

The partial tilting aircraft, a novel kind of vertical take-off and landing aircraft, lacks a suitable way to address the operational redundancy brought on by its multiple rudders. Based on the optimal control theory, the problem of longitudinal manipulation of the partial tilting aircraft is carried out, and the distribution of rudder and the dynamic tilt rotation are optimized. The longitudinal rigid body flight mechanics model was established. The first derivative of the control quantity is used as the control quantity to avoid the jumping discontinuity in the optimization process. In this research, a hybrid control equation is established and the longitudinal control surface allocation problem is investigated. The trajectory optimization problem of the transition of the aircraft is transformed into a nonlinear dynamic optimal control problem. This study selects reasonable optimization objectives and constraints to establish an optimal control model. The equation and the target function of the rudder surface are selected. The control surface allocation and optimal maneuvering strategy for transitional flight of the aircraft are determined simultaneously with the flight trajectory. Compared with the traditional approach of first determining control surface allocation based on trim calculations and then determining the flight trajectory through optimization, this method significantly improves attitude stability and reduces control load. The effectiveness of the method has been validated through simulation analysis.