Distributed composite output consensus protocols of higher-order multi-agent systems subject to mismatched disturbances

• Published in: IET control theory & applications Vol. 11; no. 8; pp. 1162 - 1172
• Main Authors: Li, Guipu, Wang, Xiangyu, Li, Shihua
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 12.05.2017
• Subjects: Algorithms; Asymptotic properties; asymptotical consensus; Control methods; control system synthesis; Control systems; Derivatives; disturbance estimation; Disturbances; Estimates; estimation theory; feedback; feedforward; feedforward‐feedback composite consensus protocol design; higher‐order derivative; leaderless case; leader‐follower case; multiagent system; Multiagent systems; multi‐agent systems; nonlinear control systems; nonlinear sliding‐mode surface; observers; output consensus protocol; PI control; proportional‐integral observer; Special Issue: Recent Developments on Sliding Mode Control and Its Applications for Complex Systems; time‐varying matched disturbance; time‐varying systems; variable structure systems; time-varying systems; multi-agent systems; PI control; estimation theory; proportional-integral observer; control system synthesis; higher-order derivative; asymptotical consensus; multiagent system; feedback; time-varying matched disturbance; disturbance estimation; output consensus protocol; leaderless case; nonlinear control systems; feedforward; leader-follower case; feedforward-feedback composite consensus protocol design; observers; variable structure systems; nonlinear sliding-mode surface
• ISSN: 1751-8644; 1751-8652
• DOI: 10.1049/iet-cta.2016.0814

In the existing literatures, most of the anti-disturbance consensus control methods focus on multi-agent systems with slow time-varying matched disturbances. In practise, the multi-agent systems are usually subject to mismatched disturbances and the disturbances are usually fast time-varying. This study investigates the output consensus problem of higher-order multi-agent systems with mismatched disturbances, which are allowed to be fast time-varying. Firstly, to estimate the matched disturbances, mismatched disturbances and their higher-order derivatives, a generalised proportional–integral observer is constructed for each agent. Secondly, by distributedly employing the estimates of the mismatched disturbances and their higher-order derivatives, for both leaderless and leader–follower cases, two kinds of non-linear sliding-mode surfaces are developed, respectively. Thirdly, with the designed surfaces and the disturbances estimation information, feedforward–feedback composite consensus protocols are designed for both cases, which guarantee asymptotical consensus of the agents' outputs. Simulation results show the effectiveness of the proposed consensus algorithms.