A Moving Frame Trajectory Tracking Method of a Flying-Wing UAV Using the Differential Geometry

Abstract

The problem of UAV trajectory tracking is a difficult issue for scholars and engineers, especially when the target curve is a complex curve in the three-dimensional space. In this paper, the coordinate frames during the tracking process are transformed to improve the tracking result. Firstly, the basic concepts of the moving frame are given. Secondly the transfer principles of various moving frames are formulated and the Bishop frame is selected as a final choice for its flexibility. Thirdly, the detailed dynamic equations of the moving frame tracking method are formulated. In simulation, a moving frame of an elliptic cylinder helix is formulated precisely. Then, the devised tracking method on the basis of the dynamic equations is tested in a complete flight control system with 6 DOF nonlinear equations of the UAV. The simulation result shows a satisfactory trajectory tracking performance so that the effectiveness and efficiency of the devised tracking method is proved.

Antidisturbance Vibration Suppression of the Aerial Refueling Hose during the Coupling Process

“…Moreover, the demanding work environment will generally make the measurement noise of the sensors inevitable. According to (2), the total disturbances F 1 will directly affect the dynamics of the speed subsystem S 1 , and the measurement noise n i will definitely affect the closed-loop performance via the feedback channel. Ultimately, the total disturbances and the measurement noise will definitely impair the closed-loop performance.…”

“…Indeed, as concluded above, the system state's movement speed is not zero when it crosses the axis e 1 (namely, the system state is in D 2 ). Therefore, although the state trajectory may cross the axis e 1 (such as e init i , i = 1, 3, 4, 6), the state e will not stay in D 2 In these cases, the states e init i , i = 1, 3, 4, 6 will cross the axis e 1 Then, they will asymptotically converge to the sliding mode s = 0 like the initial states which do not cross axis e 1 (such as, e init i , i = 2, 5). …”

“…Unmanned aerial vehicles (UAVs) [1,2] have been widely used in civilian or military fields in recent years, which include but are not limited to target tracking, combat radius increasing, flight range extending, and battle operational efficiency improving. As an effective method for increasing the endurance and range of aircraft by refueling them in flight [3], UAV autonomous aerial refueling (AAR) has attracted an increasing interest over the last decades from both theoretical and practical aspects covering aircraft control, sensor systems, and their integration [4][5][6][7][8].…”