Browsing by Author "Dixon, Warren E."

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A Switched Systems Approach to Image-Based Localization of Targets That Temporarily Leave the Camera Field of View
(2018-11-01)
Parikh, Anup
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Cheng, Teng-Hu
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Licitra, Ryan
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Dixon, Warren E.
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機械工程學系
Image sensors have widespread use in many robotics applications and, in particular, in target tracking. While existing methods assume continuous image feedback, the novelty of this brief stems from the development of dwell time conditions to guarantee convergence of state estimates to an ultimate bound for a class of image-based observers in the presence of intermittent measurements. A Lyapunov analysis for the switched system is performed to develop convergence conditions based on the minimum amount of time the object must be visible and on the maximum amount of time the object may remain outside the camera view. Experimental results are included to verify the theoretical results and elucidate real-world performance.
Decentralized Synchronization of Uncertain Nonlinear Systems With a Reputation Algorithm
(2018-03-01)
Klotz, Justin R.
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Parikh, Anup
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Cheng, Teng-Hu
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Dixon, Warren E.
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機械工程學系
Decentralized synchronization approaches generally assume that communication of state information between neigh-boring agents is completely accurate. However, just one agent's communication of inaccurate information to neighbors can significantly degrade the performance of the entire network. To help abate this problem, we present a decentralized controller for a leader-follower framework which uses local information to vet neighbors and change consensus weights accordingly. Because updates of the consensus weights produce a switched system, switching control theory techniques are used to develop a dwell-time that must elapse between agents' successive weight updates. A Lyapunov-based stability analysis is presented which develops sufficient conditions for approximate convergence of follower agents' states to a leader agent's time-varying state. Simulation results are provided to demonstrate the performance of the developed techniques.
Event-Triggered Control of Multiagent Systems for Fixed and Time-Varying Network Topologies
(2017-10-01)
Cheng, Teng-Hu
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Kan, Zhen
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Klotz, Justin R.
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Shea, John M.
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Dixon, Warren E.
A decentralized controller that uses event-triggered communication scheduling is developed for the leader-follower consensus problem under fixed and switching communication topologies. To eliminate continuous interagent communication, state estimates of neighboring agents are designed for control feedback and are updated via communication to reset growing estimate errors. The communication times are based on an event-triggered approach and are adapted based on the trade-off between the control system performance and the desire to minimize the amount of communication. An important aspect of the developed event trigger strategy is that communication is not required to determine when a state update is needed. Since the control strategy produces switched dynamics, analysis is provided to show that Zeno behavior is avoided by developing a positive constant lower bound on the minimum inter-event interval. A Lyapunov-based convergence analysis is also provided to indicate bounded convergence of the developed control methodology.