倾转旋翼飞行器无模型自适应姿态控制

Model-free adaptive attitude controller for a tilt-rotor aircraft

采用余弦加权分配法克服了控制操纵冗余问题,采用内/外回路控制结构解决了通道间耦合问题,实现了不同飞行模式下飞行控制系统统一建模。针对无人倾转旋翼飞行器动力学模型难于准确建立问题,引入伪梯度向量和伪阶数,应用无模型自适应飞行控制策略,使飞行控制系统对存在动力学特性非线性、时变性和未建模部分的被控对象具有更强的自适应性和鲁棒性。仿真验证了无模型自适应控制器的自适应性和鲁棒性优于比例-积分-微分控制器,给出了倾转旋翼飞行器由直升机模式到过渡模式再到飞机模式的全过程仿真,验证了无模型自适应控制器能够应用于倾转旋翼飞行器飞行控制系统设计,为无人倾转旋翼飞行器飞行控制系统设计,提供了一套新的控制系统设计方法,便于工程实现。

The control redundancy is overcome with a ＂cosine＂ distribution method. The coupling between control channels is resolved with inner/outer loop control configuration. A unified model of the flight control system is realized for different flight modes. In the face of difficulty from modeling dynamics of tilt-rotor air- craft, pseudo partial derivative and pseudo order are introduced, and a model-free adaptive flight control law is designed. The adaptability and robustness of the flight control system to the nonlinearity, time-varying and un certainty of controlled plant are improved. The control performance of adaptability and robustness are verified with simulation, in which the model-free adaptive flight controller is superior to proportion integration differen- tiation （PID） controller. A simulation process is given out, in which the tilt rotor aircraft emulates a flight process from helicopter mode, conversion mode to airplane mode. It is demonstrated that the model-free adap- tive control can be applied to the design of tilt-rotor aircraft flight control systems. A new control method is pro- vided for the flight control system of the tilt-rotor aircraft, which is easy to engineering implementation.