%A YAN Xufei, CHEN Renliang %T Control strategy optimization of dynamic conversion procedure of tilt-rotor aircraft %0 Journal Article %D 2017 %J Acta Aeronautica et Astronautica Sinica %R 10.7527/S1000-6893.2017.520865 %P 520865-520865 %V 38 %N 7 %U {https://hkxb.buaa.edu.cn/CN/abstract/article_16771.shtml} %8 2017-07-15 %X

The optimal control theory is applied to investigate the optimal dynamic conversion procedure of tilt-rotor aircraft to minimize the performance index described as the weighted sum of time consumed, variation of flight attitude and pilot workload. A flight dynamic model is built to extend the basic longitudinal rigid-body flight dynamic model with mixed control equations. The rates of pilot control sticks are set as the control variables to avoid jump discontinuities of controls in control strategy optimization. The dynamic conversion procedure is transformed into a dynamic optimal control problem with an appropriate performance index. The optimal control problem is formulated into a nonlinear programming problem and solved by a sparse sequential quadratic programming. XV-15 tilt-rotor aircraft is taken as the sample for the demonstration of conversion and reconversion. The results indicate that the variations of state variables are in good agreement with the data from flight simulation, and the variations of pitch attitude and pilot controls are relatively more gentle. The optimal control theory can be applied to investigate the optimal dynamic conversion procedure.