Cooperative Adaptive Fuzzy Control of
High-Order Nonlinear Multi-Agent
Systems with Unknown Dynamics
?
Jie Huang
∗,∗∗
Hao Fang
∗
Jie Chen
∗
Lihua Dou
∗
Fang Deng
∗
∗
School of Automation, Beijing Institute of Technology
Key Laboratory of Intelligent Control and Decision of Complex
Systems, Beijing, 100081, China
∗∗
Fujian Institute of Education, Fuzhou, 350025, China
(e-mail: autohuangjie@gmail.com).
Abstract: This paper focuses on the cooperative adaptive fuzzy control of high-order nonlinear
multi-agent systems. The communication network is a undirected graph with a fixed topology.
Each agent is modeled by a high-order integrator incorporating with unknown nonlinear
dynamics and an unknown disturbance. Under the backstepping framework, a robust adaptive
fuzzy controller is designed for each agent such that all agents ultimately achieve consensus.
Moreover, these controllers are distributed in the sense that the controller design for each
agent only requires relative state information between itself and its neighbors. A four-order
simulation example demonstrates the effectiveness of the algorithm.
Keywords: Multi-agent systems, Distributed control, Consensus, High-order, Backstepping,
Fuzzy logic systems
1. INTRODUCTION
Cooperative control of multi-agent systems has received
increasing attention by the fact that many benefits can
be obtained when a single complicated agent is equiv-
alently replaced by multiple simpler agents. Numerous
results have been obtained to solve a variety of multi-agent
cooperative control problems (Vicsek 1995, Jadbabaie et
al. 2003, Olfati-Saber and R.M. Murray 2002, 2004, W.
Ren and R.W. Beard 2005, 2008). The control theory
of multi-agent systems can be applied in many practical
engineering applications such as cooperative control of un-
manned ground/air/underwater vehicles, distributed sen-
sor networks, aggregation and rendezvous control, attitude
alignment of spacecraft and so on.
Among the existing works mentioned above, most of them
studied only the first- and second-order dynamics. Recent-
ly, some researchers turned to focus on the distributed
cooperative control problems of the networked high-order
systems. Ren et al. (2006) showed a matrix approached
based framework for high-order multi-agent systems. Con-
sensus of high-order integrators multi-agent systems with
time-delays and switching topologies were studied by Jiang
et al. (2010) and Yang et al. (2011). Coordination of high-
order linear systems with disturbances was investigated
by Mo et al.(2011). Discrete-time high-order linear multi-
?
This work was supported by Projects of Major Internation-
al (Regional) Joint Research Program (No.61120106010), Nation-
al Science Foundation for Distinguished Young Scholars of Chi-
na (No.60925011), National Natural Science Foundation of Chi-
na (No.61175112), Fujian Institute of Education Research Project
and Beijing Education Committee Cooperation Building Foundation
Project.
agent systems was considered by Lin et al. (2011), and
there also many results for the general high-order linear
time-invariant (LTI) systems. As for the consensus of
multiple high-order nonlinear systems, Dong et al. (2011)
considered the tracking control problem. In term of coop-
erative adaptive control for high-order nonlinear uncertain
multi-agent systems, the challenge is to make sure that the
control for the nonlinearities and uncertainties are also
in the distributed manner. That is, they are allowed to
depend only on locally available information about the
agent and its neighbors. Due to the challenges in designing
cooperative control laws for distributed systems, it is not
straightforward to extend the results for first- and second-
order systems to that with higher-order dynamics. In these
issues, the unknown dynamics can be considered under
the neural network(NN) control framework (Zhang et. al
2012) or adaptive fuzzy control framework. Backstepping
control approaches with adaptive fuzzy control can provide
a systematic methodology of solving control problems for
a larger class of unknown nonlinear systems (Tong et al.
2009a, 2009b, and Huo et al. 2012), where fuzzy logic
systems(FLS) are used to approximate unknown nonlinear
functions, and the backstepping design technique is ap-
plied to construct adaptive controllers and the adaptation
parameter laws.
In this paper, a distributed recursive design approach is
proposed to archive consensus of multiple high-order non-
linear systems with uncertainties. The main works of this
paper include: 1) First, the agent dynamics are extended to
general higher-order nonlinear systems in the Brunovsky
form, which include first- and second-order systems as spe-
cial cases. 2) Second, we propose a systematical distributed
fuzzy logic systems and backstepping framework for multi-