  This paper investigates a robust positive consensus problem for a class of
heterogeneous high-order multi-agent systems subject to external inputs.
Compared with existing multi-agent consensus results, the most distinct feature
of the formulated problem is that the state variables of all heterogeneous
agents are confined in the positive orthant. To solve this problem, we present
a two-step design procedure. By constructing an auxiliary multi-agent system as
positive local reference generators, we incorporate the reference generator
into some applicable decentralized robust tracking controller for each agent.
The proposed distributed algorithm is proven to ensure a robust consensus
fulfilling certain prescribed pattern for the multi-agent system under
switching topology in the sense of finite-gain stability with respect to the
external inputs. A simulation example is finally given to illustrate the
effectiveness of our design.
