快速模型预测控制用于微型直升机航迹跟踪

为实现微型共轴无人直升机(MCUH)的航迹跟踪,考虑系统的状态和输入约束,利用非线性模型预测控制(NMPC)技术设计一种快速在线的控制器。首先,简化MCUH的非线性模型,利用系统的微分平坦特性生成满足直升机动力学的可行航迹,沿着该航迹对系统进行线性化,得到近似直升机非线性动力学的线性时变(LTV)模型。然后,将传统输出航迹跟踪NMPC问题转化为LTV-MPC优化问题,降低问题的复杂度,为确保航迹跟踪误差系统的指数渐近稳定,分别设计终端域和终端罚值。最后,通过数值仿真,验证快速在线NMPC策略的可行性。结果表明:设计的预测控制器误差控制精度高、求解速度快,可实现对有约束的时变航迹的跟踪。

A fast Model Predictive Control Approach to Trajectory Trackingof Miniature Coaxial Helicopter

A fast online nonlinear model predictive control (NMPC) approach was applied to trajectory tracking of miniature coaxial unmanned helicopter(MCUH). The nonlinear model of MCUH was simplified. And then, utilizing the differential flatness of MCUH, a linear time varying (LTV) model was employed to approximate the nonlinear dynamic behavior of MCUH, and further on applied in the conversion from classical NMPC schemes to LTV-MPC schemes for output trajectory tracking, resulting in reduction of the complexity of the problem solving. Afterwards, the terminal region and the end penalty were designed to ensure the exponentially asymptotically stable of the trajectory tracking error system. The numerical simulation verified the proposed NMPC control scheme to the time-varying trajectory tracking of MCUH with constraints.