- Title
- Synchronization of nonlinear heterogeneous multi-agent systems with complex networks
- Creator
- Khan, Gulam Dastagir
- Relation
- University of Newcastle Research Higher Degree Thesis
- Resource Type
- thesis
- Date
- 2019
- Description
- Research Doctorate - Doctor of Philosophy (PhD)
- Description
- Multi-agent systems (MASs) have attracted the attention of researchers in various fields in recent years. The research of MASs is motivated by observations of interesting phenomena in nature and is deepened by its applications in engineering. In the past, several approaches have been employed to achieve consensus or synchronization of linear and homogeneous MASs. Many interesting and good results have been obtained for the synchronization of nonlinear heterogeneous MASs with comparatively simple dynamics under some network constraints. However, many problems and challenges in nonlinear heterogeneous multi-agent system are still unanswered. In this thesis, we mainly consider the synchronization of nonlinear heterogeneous multi-agent systems with complex networks, especially under network switching and event-triggered based network communication. These two network anomalies threaten the stability of the over all system and eventually prevent the MASs from reaching the final objective of consensus/synchronization. In the case of network switching constraint, we study the output synchronization problem for nonlinear heterogeneous multi-agent systems in a switching network of time-varying directed graphs. The scenario under consideration is complicated in the sense that none of the graphs is assumed to be connected (containing a spanning tree). Within a two-step framework for output synchronization of nonlinear heterogeneous multi-agent systems, the main technical challenge lies in the existence of switching strategies under which a class of switched unstable subsystems subject to external perturbation can be input-to-state stabilized. Specifically, the problem lies in finding a switching signal for a family of unstable linear subsystems such that the overall system is input-to-state stable (ISS) with respect to external input. To deal with the event-triggered based network communication restriction, a certain input-to-state stability (ISS) property from the measurement (sensor) disturbance to state is employed for stability analysis and controller synthesis of nonlinear event-triggered systems. Specifically, a new event-triggered stabilization technique is proposed that requires a milder condition that the controlled system has a certain ISS property from the input (actuator) disturbance to state. The technique is further applied to explicitly construct an event triggered controller for the output regulation problem of a class of nonlinear systems. It is assured that the Zeno behaviour is avoided at all time. The above sketched event-triggering technique is then applied to addresses the output synchronization problem of heterogeneous nonlinear multi-agent systems with distributed event-based controllers. Employing the two-step synchronization process, we first outline the distributed event-triggered consensus controllers for linear reference models under directed communication topology. Secondly, by using certain input-to-state stability (ISS) property, we design an event-triggered perturbed output regulation controllers for each nonlinear multi-agent. It is further shown that the subsequent triggering instants are based on the intermittent communication. The objective of output synchronization is successfully achieved with Zeno behavior avoided. The two-fold result given in this work has contribution to development of networked event-triggering mechanisms for both linear systems and nonlinear systems. Some typical examples have been provided to verify the effectiveness of developed methodologies.
- Subject
- synchronization; nonlinear systems; event-triggered control; switching topology; multi-agent systems; networks
- Identifier
- http://hdl.handle.net/1959.13/1406557
- Identifier
- uon:35645
- Rights
- Copyright 2019 Gulam Dastagir Khan
- Language
- eng
- Full Text
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| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | ATTACHMENT01 | Thesis | 43 MB | Adobe Acrobat PDF | View Details Download | ||
| View Details Download | ATTACHMENT02 | Abstract | 275 KB | Adobe Acrobat PDF | View Details Download |