仅有角测量的被动式机动目标跟踪

以往的被动式跟踪研究往往假定目标作匀速直线运动, 采用目标与跟踪站的相对距离和速度为状态变量, 因而相应的跟踪滤波器不能跟踪机动目标. 研究了仅有角测量的机动目标跟踪问题, 采用目标的位置、速度及加速度作为状态变量, 并对测量方程进行适当变换, 推导出一种伪线性机动目标自适应跟踪算法, 可用于单站或多站被动式机动目标跟踪. 大量的仿真研究表明了本算法的有效性, 其中多站跟踪比单站跟踪具有更高的精度、算法稳定性和快速收敛性.  

Formations on directed cycles with bearing‐only measurements

This paper studies a bearing‐only–based formation control problem for a group of single‐integrator agents with directed cycle sensing topology. In a 2‐dimensional space, a necessary and sufficient condition for the set of desired bearing vectors to be feasible is derived. Then, we propose a bearing‐only control law for every agent and prove that the formation asymptotically converges to a formation specified by a set of feasible desired bearing vectors. Analysis of the equilibrium formations in the plane for a 3‐agent system and subsequent extension to an n‐agent system is provided. We further extend the analysis on directed triangular formation into a 3‐dimensional space. Finally, simulations validate the theoretical results.  

Bearing‐only control of directed cycle formations: Almost global convergence and hardware implementation

In this article, we study bearing‐only control of directed cyclic formations. First, we provide a necessary and sufficient condition on the bearing constraints so that the directed cycle formation of n‐agents in (n−1)‐dimensional space is infinitesimally bearing rigid. Second, a bearing‐only control law which only allows motions perpendicular to the desired bearing vector is proposed. Under this control law, the agents globally asymptotically converge to a desired formation which is fully determined from their initial positions and desired bearing vectors. Finally, the proposed formation control law is implemented on mobile robots to support the analysis.  

Graph-theoretic characterization of fixed modes in centralized and decentralized control

A closed-loop system is represented by a weighted directed graph which exhibits all couplings of the system in a very clear and simple manner. The coefficients of the characteristic polynomial of the closed-loop system may be obtained with the aid of cycle families in this graph. Based on this result, a criterion for the existence of fixed modes is derived. The multiplicities of fixed modes may also be determined graph-theoretically. The consequences of structural constraints on the output feedback pattern become evident. Decentralized feedback is discussed as a special case.