Silun Zhang

Intrinsic reduced attitude formation with ring inter-agent graph

This paper investigates the reduced attitude formation control problem for a group of rigid-body agents using feedback based on relative attitude information. Under both undirected and directed cyc ...

Intrinsic Tetrahedron Formation of Reduced Attitude

Abstract 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 S 2 , which is shown to be an efficient approach to reduced attitude formation problems.

Finite-time attitude synchronization with a discontinuous protocol

A finite-time attitude synchronization problem is considered in this paper where the rotation of each rigid body is expressed using the axis-angle representation. One simple discontinuous and distributed controller using the vectorized signum function is proposed. This controller only involves the sign of the state differences of adjacent neighbors. In order to avoid the singularity introduced by the axis-angular representation, an extra constraint is added to the initial condition. It is proved that for some initial conditions, the control law achieves finite-time attitude synchronization. One simulated example is provided to verify the usage of the control protocol designed in this paper.

Asynchronous cooperative guidance for multiple intercepting flight vehicles: A dynamic target coverage approach

In this paper, a problem how multiple intercepting flight vehicles intercept a high-speed maneuvering target is considered. Due to the uncertainties of the target caused by the background noises and low detection accuracy of the intercepting flight vehicles, we use a dynamic distribution to describe the location of target. Therefore, the cooperative intercepting problem is transformed into a problem to cover a known dynamic distribution. In order to deal with the dynamic target coverage problem more effective, an asynchronous cooperative way is considered in this paper. Based on dynamic target coverage theory, a finite time cooperative guidance law is developed, and with the cooperative guidance law the reachable sets of the intercepting flight vehicles can cover the target dynamic distribution as much as possible to maximize the probability of interception and guarantee collision avoidance.

Guidance Law Design for Intercepting a Target with Multiple Decoys

In this paper, we investigate the interception problem of a target with multiple decoys. These decoys appear as apparent points and only can be distinguished with the approaching of the flight vehicle and the real target. Due to the limitation of the flight vehicle maneuverability, these apparent points should be considered as the real ones otherwise a large miss distance might be caused between the flight vehicle and the real target even the interception task might be failed. We first establish the mathematical description of the one-to-many guidance engagement problem, and formulate it into a hybrid switched system by introducing a multiple-valued logic variable. The Fliess functional expansion is adopted to express the input and output relationship of the switched hybrid system. Then, the optimal switching control command is determined for a multiple-step output tracking performance index and a simple brutal method is used to calculate the optimal switching control command. The target orientation at each time interval is determined. Simulation results show the effectiveness of the proposed method.