动力学参数未知的四旋翼无人机预定性能控制

Prescribed performance control for quadrotor UAV with unknown kinetic parameters

针对具有外部气流干扰、空气阻力和时变负载的不确定四旋翼无人机,考虑动力学参数未知的情况,基于自适应动态表面控制框架,提出了一种新的双闭环预定性能控制方法。将四旋翼无人机系统解耦为双环,即外环位置子系统和内环姿态子系统,内外环通过姿态提取算法连接。分别针对位置和姿态子系统,利用自适应方法对系统的未知动力学参数、空气阻力和外界干扰进行估计,同时引入新的坐标变换作用于跟踪误差,基于Lyapunov稳定理论,提出预定性能控制器设计方法,使闭环系统跟踪误差一致最终有界稳定,且整个动态过程中满足暂稳态性能要求。所提方法克服了系统动力学参数和负载精确已知的局限性,避免了预定性能控制设计中复杂的求逆过程。通过仿真实例验证了所提方法的有效性和优越性。

A new double closed loop and prescribed performance control method based on adaptive dynamic-surface frames is proposed for the uncertain quadrotor UAV with unknown external airflow disturbance,air resistance and time-varying load.During the design process,the four-rotor UAV system is decoupled into two loops:the outer loop position subsystem and the inner loop attitude subsystem,connected by attitude extraction algorithm.For the position and attitude subsystems,the unknown dynamic parameters,air resistance and external interference of the system are estimated by using the adaptive method.A new coordinate transformation is then introduced to act on the tracking errors.Based on the Lyapunov stability theory,a new method is proposed for the design of a prescribed performance controller to make the tracking error of the closed-loop system uniform,achieving ultimate bounded stability.The transient and steady-state performance requirements are met in the whole dynamic process.Compared with the existing results,our results overcome the limitations of accurately known system kinetic parameters and loads,and avoid the complicated inverse process in the design of the prescribed performance control.Finally,the simulation examples are provided to verify the effectiveness and superiority of the proposed method.