Hierarchical control for autonomous teams

Chandler, Phillip; Afb, Wright-Patterson; Pachter, Meir

doi:10.2514/6.2001-4149

Cited by 61 publications

(31 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In particular, here Uz' is dominated by u2 with respect to chasing both evader el and e2. Thus, ul is strictly better than Uz in the optimization problem (11). Since u' ( 12, the statement is proven for…”

Section: Structured Approach and Iterative Improvementmentioning

confidence: 60%

“…E Theorem IV.8 specifies the structure of the improving control. It has a potential of reducing computation of optimization (11) in the following aspects: 1) the search space for possible cooperative controls is restricted to a small region, as 12 in Fig.3; 2 The following numerical example verifies Theorem IV.8.…”

Section: Structured Approach and Iterative Improvementmentioning

confidence: 78%

“…At =a a =argmin{JV(x;a)},forxcXt}; that in the optimization of pursuers in (11), all possible controls over the entire space A are considered instead ofthe restricted control set As in (8). This relaxation on the xo control structure enables a better coordination ofpursuers and this is argued as follows.…”

Section: Structured Approach and Iterative Improvementmentioning

confidence: 99%

See 2 more Smart Citations

Improvement with Look-ahead on Cooperative Pursuit Games

Cruz

2006

Proceedings of the 45th IEEE Conference on Decision and Control

View full text Add to dashboard Cite

Abstract-The multi-player Pursuit-Evasion (PE) game problem has recently received a lot of attention. Hierarchical decomposition is previously proposed for multi-player differential game for a suboptimal solution [5]. Furthermore, optimization based on limited look-ahead is used to improve such a suboptimal solution [4]. However, it requires intensive computation. In this paper, through the further study on the properties of the suboptimal value function of a cooperative pursuit game, it becomes evident that the performance improvement by limited look-ahead results from the structure relaxation on pursuers' strategies when optimization is conducted. Based on a problem with certain objective and dynamics, we prove a linear structure of the improving strategies in terms of the structured controls associated with the suboptimal solution, and then optimization is parameterized by the linear weights. The problem is further transformed into a nonlinear programming problem. It is shown that computation can be reduced the decentralized implementation is possible.

show abstract

Section: Structured Approach and Iterative Improvementmentioning

confidence: 60%

Section: Structured Approach and Iterative Improvementmentioning

confidence: 78%

See 1 more Smart Citation

Improvement with Look-ahead on Cooperative Pursuit Games

Cruz

2006

Proceedings of the 45th IEEE Conference on Decision and Control

View full text Add to dashboard Cite

show abstract

“…Finally, one needs to search the cost table for the directed graph to find a state transition sequence of minimum cost that starts with the initial state and covers all the targets. Several publications 1,2,9 in the literature have addressed the search problem and that is not the topic under investigation in this paper. As our interest is in demonstrating the effect of wind on the task assignment problem, we consider two examples with 3 targets each and the direct graph search was done manually with some effort.…”

Section: Optimal Tour Planningmentioning

confidence: 99%

“…[1][2][3] This new paradigm for control has been implemented in the MultiUAV simulation platform by the Air Force Research Laboratory.…”

Section: Introductionmentioning

confidence: 99%

Tour Planning for an Unmanned Air Vehicle Under Wind Conditions

McNeely

Iyer

Chandler

2007

Journal of Guidance, Control, and Dynamics

View full text Add to dashboard Cite

A very important sub-problem in the task assignment problem for unmanned air vehicles (UAVs) is the evaluation of costs for the state transitions of a directed graph. Usually a Dubins vehicle flying in the absence of wind is considered in the computation of costs. However, when a prevailing wind vector field is considered, the costs taken on very different values and the task assignment problem can have very different solutions. In this paper, we consider the problem of constructing minimum time trajectories for a Dubins vehicle in the presence of a time varying wind vector field. We present results on the existence and uniqueness of minimum-time solutions for a Dubins vehicle flying in a general time-varying wind vector field under some technical conditions. These results extend the conclusions of the well-known Dubins theorem. We also propose an algorithm for obtaining the minimumtime solution for an UAV and prove its convergence. We also present the results of numerical experiments that show that the importance of considering wind vector fields while planning the tour for an UAV.

show abstract