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This paper addresses formation control of reduced attitudes in which a continuous control protocol is proposed for achieving and stabilizing all regular polyhedra (also known as Platonic solids) under a unified framework. The protocol contains only relative reduced attitude measurements and does not depend on any particular parametrization as is usually used in the literature. A key feature of the control proposed is that it is intrinsic in the sense that it does not need to incorporate any information of the desired formation. Instead, the achieved formation pattern is totally attributed to the geometric properties of the space and the designed inter-agent connection topology. Using a novel coordinates transformation, asymptotic stability of the desired formations is proven by studying stability of a constrained nonlinear system. In addition, a methodology to investigate stability of such constrained systems is also presented., QC 20200205

In this work, a methodology based on differential geometry techniques is proposed to investigate exponential stability of a formation for reduced attitudes. By the proposed method, there is no need in finding any relative coordinates, which is typically needed but shown to be difficult when the formation problem is evolving in a non-Euclidean space. In this paper, the desired formation is treated as an embedding submanifold in (S-2)(N) and by using the rotation symmetries owned by the attitude dynamics its stability is directly examined. Moreover, such a method turns out to be coordinates free, namely, exponential stability of a formation can be completely determined by just investigating any one equilibrium which can result in the formation under any local chart of (S-2)(N). This greatly simplifies the stability analysis for the formation problems., QC 20190117

In this paper, formation control for reduced attitude is studied, in which a regular tetrahedron formation can be achieved and shown to be asymptotically stable under a large family of gain functions in the control. Moreover, by further restriction on the control gain, almost global stability of the desired formation is obtained. In addition, the control proposed is an intrinsic protocol that only uses relative information and does not need to contain any information of the desired formation beforehand. The constructed formation pattern is totally attributed to the geometric properties of the space and the designed inter-agent connection topology. Besides, a novel coordinates transformation is proposed to represent the relative reduced attitudes in S2, which is shown to be an efficient approach to reduced attitude formation problems., QC 20171211

This paper addresses formation control of reduced attitudes in which a continuous protocol is proposed for achieving and stabilizing all regular polyhedra (also known as Platonic solids) under a unified framework. The protocol contains only relative reduced attitude measurements and does not depend on any particular parametrization as is usually used in the literature. A key feature of the control proposed is that it is intrinsic in the sense that it does not need to incorporate any information of the desired formation. Instead, the achieved formation pattern is totally attributed to the geometric properties of the space and the designed inter-agent connection topology. Using a novel coordinates transformation, asymptotic stability of the desired formations is proven by studying stability of a constrained nonlinear system. In addition, a methodology to investigate stability of such constrained systems is also presented., QC 20180305

In this paper, we study the problem of tracking and encircling a moving target by agents in 3D. Specifically, a group of agents are driven to some desired formation on a spherical surface and simultaneously keep the center of this spherical formation coinciding with the target to be tracked. In our control design, the desired formation is not used as a reference signal for tracking. Rather by designing communication topology for the agents we can achieve the desired formation using relative positions only. We can also place the desired cyclic formation on the equator if the north pole is specified., QC 20161129

This paper considers the guidance and control problem of a flight vehicle with a seeker installed on the side of its head for avoiding the aerodynamic heating. In order to guarantee the target remaining in the seeker's sight of view, the line of sight and the attitude of the flight vehicle should be under some constraints which cause coupling between the guidance and the attitude control. Therefore, the integrated guidance and control (IGC) is necessary. We first formulate the guidance and control problem of the interceptor into an IGC problem with constraints. Then, a singular perturbation-based design approach is proposed to decompose the IGC problem into the control design of the quasi-steady-state subsystem and the boundary-layer subsystem individually. The receding horizon control is applied in the control design for the two subsystems. Simulation results show the effectiveness of the proposed approach., QC 20170327

QC 20170303