Automatic cruise control of a platoon of multiple connected vehicles in an automated highway system has drawn significant attention of the control practitioners over the past two decades due to its ability to reduce traffic congestion problems, improve traffic throughput and enhance safety of highway traffic. This paper proposes a two-layer distributed control scheme to maintain the string stability of a heterogeneous and connected vehicle platoon moving in one dimension with constant spacing policy assuming constant velocity of the lead vehicle. A feedback linearization tool is applied first to transform the nonlinear vehicle dynamics into a linear heterogeneous state-space model and then a distributed adaptive control protocol has been designed to keep equal inter-vehicular spacing between any consecutive vehicles while maintaining a desired longitudinal velocity of the entire platoon. The proposed scheme utilizes only the neighbouring state information (i.e. relative distance, velocity and acceleration) and the leader is not required to communicate with each and every one of the following vehicles directly since the interaction topology of the vehicle platoon is designed to have a spanning tree rooted at the leader. Simulation results demonstrated the effectiveness of the proposed platoon control scheme. Moreover, the practical feasibility of the scheme was validated by hardware experiments with real robots.

This paper proposes a fully distributed control protocol that achieves time-varying group formation tracking for linear multiagent systems connected via a directed graph. The group formation tracking often leads to sub-formations especially when the leaders are placed far apart or they have separate control inputs. In the proposed approach, the followers are distributed into several subgroups and each subgroup attains the predefined subformation along with encompassing the leaders. Each subgroup can be assigned multiple leaders, contrary to the single-leader case considered in most existing literature, which makes the current problem nontrivial. When multiple leaders exist in a subgroup, the subformation attained by that subgroup keeps tracking a convex combination of the states of the leaders. A distributed adaptive control protocol has been introduced in this paper which uses only relative state information and, thus, avoids direct computation of the graph Laplacian matrix. Due to the virtue of this, the proposed scheme remains effective even when some of the agents get disconnected from the network due to sudden communication failure. An algorithm is provided to outline the steps to design the control law to attain time-varying group formation tracking with multiple leaders. Toward the end, a case study on multitarget surveillance operation is taken up to show an important application of the proposed adaptive control technique.

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This article addresses the problem of designing a two-layer distributed formation-containment control scheme for linear time-invariant swarm systems with directed communication topology, where the states of the leaders attain a prespecified time-varying/stationary formation and the states of the followers converge into the convex hull spanned by the states of the leaders. To achieve formation-containment, a set of distributed control protocols is developed utilizing the neighboring state information, which enables the proposed scheme operate without using global information about the entire interaction topology. The conditions to achieve formation-containment are suggested and a theoretical proof of the proposed scheme is also derived exploiting the Lyapunov stability approach. An algorithm is written to provide systematic guidelines on how to implement the control protocols in practice. It is argued that the consensus problem, formation tracking problem, and containment control problem can all be viewed as special cases of formation-containment. A simulation case study has been presented to demonstrate the usefulness and effectiveness of the proposed scheme and moreover, lab-based hardware experiments involving networked mobile robots were performed to test the feasibility of the scheme in real-time implementation.

This paper deals with the problem of designing a fully-distributed and robust secondary control scheme for voltage and frequency restoration of islanded microgrids along with real power sharing. Compared to the existing developments in this topic, the proposed multi-agent consensus-based secondary control scheme takes into account the effects of model uncertainty, parameter variation and unmodelled dynamics and thereby, offers a certain degree of robustness against all these factors. Due to virtue of the fully-distributed control configuration, each distributed generating (DG) unit in a microgrid requires only the information of its own and some of its neighbours but not of all other DG units attached to that microgrid. This helps in reducing the bandwidth requirement and cost of the underlying communication network and also causes enhanced flexibility and reliability of the overall microgrid operation. The proposed scheme counteracts any fluctuation in the terminal voltage and frequency of the DG units and also facilitates real power sharing among them at a pre-specified ratio despite the time-varying load disturbances, various power line faults, communication delays, etc. Finally, an exhaustive case study on a prototype IEEE 14-bus microgrid system containing five DG units has been accomplished to demonstrate the usefulness of the developed scheme.