摘要：This paper presents a robust nonlinear controller design approach for uncertain quadrotors to implement trajectory tracking missions. The quaternion representation is applied to describe the rotational dynamics in order to avoid the singularity problem existing in the Euler angle representation. A nonlinear robust controller is proposed, which consists of an attitude controller to stabilize the rotational motions and a position controller to control translational motions. The quadrotor dynamics involves uncertainties such as parameter uncertainties, nonlinearities, and external disturbances and their effects on closed-loop control system can be guaranteed to be restrained. Simulation results on the quadrotor demonstrate the effectiveness of the designed control approach.

摘要：针对单目未标定机器人视觉伺服系统中目标位姿估算问题,设计了一个基于quaternion(四元数)的扩展卡尔曼滤波器。该算法引入四元数描述目标姿态角,以四元数、目标在相机坐标系中的位置、运动速度作为状态向量,以目标特征点在成像平面的像素坐标为观测向量。利用MATLAB分析协方差矩阵R、Q对算法的影响,并确定最优的协方差矩阵。文末通过MATLAB仿真和实验研究对该算法进行了验证,并与传统EKF进行了比较,结果表明,本文提出的算法能显著提高目标位姿估算精度,可以满足应用要求。

摘要：In simulation,sometimes we wish to stipulate a specified angular velocity applied to a given *** position,linear velocity and orientation interpolations are well studied,less attention is paid on angular velocity *** this paper,a new method to smoothly interpolate angular velocity using quaternions is *** method can be easily incorporated into a key frame animation *** angular velocity at an arbitrary time can be calculated easily by our *** method can also be generalized to smoothly interpolate orientations.