在飞行器的控制中,角速率反馈可以提高控制系统的动态特性,但速率陀螺价格昂贵,且随运行时间的增加其性能会不断下降.对此本文提出了一种基于滤噪微分器的四旋翼飞行器滑模变结构控制律.该控制律使用的反馈信号仅由角度传感器得到,而无需角速率传感器.控制律中的角速率信息由王新华等设计的有限时间收敛的微分器得到.本文通过数学证明,给出了当测量信号中含有噪声时该微分器的理论跟踪误差上界.仿真以及对四旋翼飞行器滚转姿态的控制实验验证了微分器的抑制噪声作用和控制算法可行性.
Angular rate feedback can improve dynamic performance of flight control systems. However, rate gyros are generally expensive and are often prone to degradation. A sliding-mode control scheme based on noise-attenuation differentiator is proposed for the four-rotor aircraft. The scheme only needs signals from attitude sensors instead of rate gyros. The angular rate information used in the scheme is obtained from a noise-attenuation differentiator which is proposed by Wang et al.. Theoretical analysis of the noise-attenuation performance of the differentiator is presented and an expression of the upper bound of the tracking error is derived in this paper. Simulations and experiments on a prototype of four-rotor aircraft are given to demonstrate the effectiveness and feasibility of the proposed scheme.