A Distributed Observer for a Class of Nonlinear Systems and Its Application to a Leader-Following Consensus Problem

Adaptive Consensus and Parameter Estimation of Multi-Agent Systems with An Uncertain Leader

“…Remark 1. Problem 1 was studied in [5,8,25] using a distributed observer approach under the assumption that the parameters of the leader are known exactly. However, this assumption is restricted in practical applications.…”

“…We consider the case when the output signal y 0 of the leader in (2) is a sum of l sinusoids with unknown amplitudes, frequencies and phases, and it is available only to some followers. Distributed adaptive observers proposed in references [5,8,[25][26][27]29] require that some followers know the full state of the leader. Therefore, they cannot be applied in this case The result in this paper will allow us to deal with multi-tone sinusoidal signals with arbitrary unknown amplitudes, initial phases and frequencies based on only the output of the leader.…”

“…M ULTI-AGENT coordination attracts gradually increasing research interests and many problems of it have been extensively studied, such as leaderless consensus problem [1][2][3][4], leader-following consensus problem [5][6][7][8][9][10], formation control problem [11,12] and distributed optimization problem [13][14][15]. The parameters of the leader play a key role in the design of distributed control laws for solving the cooperative control problem of a multi-agent system.…”

“…Reference [25] firstly proposed a distributed observer to solve the leader-following problem under the assumption that each agent knows the system matrix of the leader. The distributed observer for a nonlinear leader with known parameters was investigated in [8]. Then, the assumption that the parameters of the leader are known by each follower is relaxed in [5] and it is assumed that only the followers who are the children of the leader know the parameters of the leader.…”

Experimental output regulation of permanent magnet synchronous motor position servo system: An internal model-based two-step control approach

“…By incorporating a suitable internal model in the controller, precise trajectory tracking, disturbance rejection and robustness can be achieved. Recently, NOR theory has been used to solve various control problems of nonlinear multi-agent systems (Guo et al, 2018; Huang and Lan, 2017; Liu and Huang, 2019; Wang et al, 2018) and MIMO nonlinear systems (Bin and Marconi, 2020; Ping et al, 2016; Wang et al, 2017b; Zhong et al, 2017). Apart from theoretical development, NOR theory has also been applied to solve trajectory tracking and disturbance rejection problem of various practical systems in industrial applications such as optical disk drive (Kim et al, 2011), gantry systems (Zhang et al, 2013), lock-up clutch system (Umemura and Sakamoto, 2015), piezoelectric actuators with hysteresis (Chen et al, 2017), PMSM speed servo system (Ping et al, 2018), and PMSM position servo system (Ping et al, 2020).…”