Average consensus of heterogeneous nonlinear multi-agent systems over directed topologies in non-ideal, uncertain and faulty environment via distributed resilient adaptive PID control

Although the average consensus is a fundamental topic in distributed control of Multi-Agent Systems, the design of resilient control strategies over directed communication topologies in the presence of different sources of uncertainty and adversarial effects, is still lacking. The purpose of this article is to bridge this gap by proposing a novel adaptive protocol that enables a MAS to achieve and preserve the mean value of the agent initial conditions against the following factors: i) heterogeneous unknown and nonlinear agent dynamics; ii) actuator faults and external disturbances; iii) inter-agent communication networks described by directed topologies. A fully-distributed and resilient Proportional-Integral-Derivative controller, in combination with a synchronized reference generator, is proposed for the robust average consensus achievement in these non-ideal environments. This is ensured while avoiding any knowledge of global information on communication graphs and without exploiting additional state-observers, thus alleviating the computational load. Adaptive mechanisms are established via the Lyapunov theory, proving the stability of the overall networked system and the boundedness of all closed-loop signals. Moreover, the proposed approach can be tailored for different kinds of PID-like strategies and any of their combinations. Finally, extensive simulation results highlight the efficacy of the developed methodology.