Meichen Guo

Cooperative Output Regulation of Heterogeneous Nonlinear Multi-Agent Systems With Unknown Control Directions

This technical note considers global cooperative output regulation for a class of heterogeneous nonlinear multi-agent systems. By using the internal model principle and the adaptive control technique, a novel distributed adaptive control scheme is developed. Contrary to most existing results, the proposed controller is applicable to multi-agent systems with agents of non-identical relative degrees and non-identical unknown control directions under a general digraph. Moreover, any existing Nussbaum-type functions can be adopted in the proposed control scheme, and the adopted Nussbaum-type functions can be non-identical for each agent. It is shown that global cooperative output regulation of the controlled multi-agent system can be achieved under some mild assumptions. A numerical example is finally presented to illustrate the effectiveness of the proposed controller.

Global cooperative output regulation for nonlinear multi-agent systems with unknown control directions

This paper proposes a novel two-layer distributed control scheme for global cooperative output regulation for a class of nonlinear multi-agent systems. The concerned systems are (i) heterogeneous and uncertain, (ii) with unknown local control directions, and (iii) under a directed communication graph. To cope with the problem, a two-layer control structure is first configured and distributed and decentralized laws are developed for the layers respectively. Then we demonstrate that combination of the control laws may lead to an effective solution to the cooperative output regulation problem. Finally, an illustrative example is given to show the effectiveness of the proposed control algorithm.

Global robust output regulation for a class of nonlinear output feedback systems

This paper considers the global robust output regulation problem of nonlinear output feedback systems in the case that both exosystem and high-frequency gain sign are unknown. The unavailability of these information poses challenges in the control law design. To solve the output regulation problem, a feedback controller is proposed by integrating the internal model principle, certainty equivalence adaptive control scheme and the Nussbaum gain technique.

Output regulation of output feedback systems with unknown exosystem and unknown high-frequency gain sign

This paper discusses the global robust output regulation problem for a class of nonlinear output feedback systems. It is assumed that the exosystem and the high-frequency gain sign are unknown and that the unknown parameters can be arbitrarily large. To solve this problem, two major challenges are to be overcome. First, the concurrence of the unknown exosystem and the unknown high-frequency gain sign cannot be handled merely by designing estimators for the two unknown parameters respectively. Second, the conventional extended matching design approach cannot be directly implemented, owing to the arbitrarily large unknown parameters. To cope with these difficulties, a new estimator is developed, and the extended matching design approach is modified to obtain a suitable update law for the estimator. The effectiveness of the proposed adaptive controller is illustrated by an example.

Adaptive cooperative output regulation of multi-agent systems in nonlinear lower triangular form

This paper considers a global cooperative output regulation problem for a class of multi-agent systems in nonlinear lower triangular form. Specifically, we focus on the problem under three relaxed conditions: (i) the agents have non-identical arbitrary relative degrees, (ii) the control directions are unknown and non-identical, and (iii) the communication graph is directed. To overcome these challenges, we develop a novel dynamic compensator based distributed controller. Moreover, the proposed controller is applied to cooperative control of a group of Lorenz systems to show the effectiveness of the proposed control scheme.