In this paper, the consensus problem of heterogeneous multi-agent systems under directed topology is investigated. Specifically, this system is composed of three classes of agents respectively described by first-order, second-order and third-order integrator dynamics. By the aid of linear filter, graph theory and matrix theory, the consensus problem is realized based on the two proposed consensus protocols. Moreover, group consensus can also be solved by adjusting parameters. Finally, some examples were presented to illustrate the theoretical results. Our study is expected to establish a more realistic model and provide a method to solve the consensus problem of heterogeneous multi-agent systems in more complex situations.

In order to reduce the offshore wind power operation and maintenance vessel motion induced by severe sea states, a suitable stabilizer with the ship based on linear quadratic regulator strategy is proposed in this paper. First of all, the dynamics of the ship motion model are established to study the longitudinal control system. The six degrees of freedom nonlinear motion model and nonlinear coupled longitudinal motion (heave and pitch) model are described in detail in this paper. Secondly, this work presents matching suitability between the T-foil and the operation and maintenance vessel. Therefore, the most suitable installation position and the optimum strut’s height of T-foil are determined by meshing the ship hull model, setting the water channel, and a series of corresponding computer fluid dynamic simulation. Following that, the linear quadratic regulator controller is studied with active longitudinal control system based on the suitable T-foil. Furthermore, a longitudinal control system is built, including free vessel module and the suitable T-foil stabilizer-based proposed controller module. Finally, the simulation results indicate that the designed T-foil and the longitudinal control system are feasible and effective to ensure the heave and pitch motion reduction based on the proposed controller.

This paper presents a finite-time fault-tolerant control strategy based on a novel reaching law, which is proposed as a solution to the trajectory tracking problem of a quadrotor unmanned aerial vehicle (UAV) in the presence of external disturbances, system uncertainties, and actuator faults. First, a novel adaptive reaching law is proposed, which enables the sliding mode surface to approach the origin with minimal rate, thus effectively reducing the chattering. Then, a high-order sliding mode observer (HOSMO) is designed to estimate the unmeasured linear velocity and the lumped uncertainties. Furthermore, the controller is designed by combining a non-singular fast terminal sliding mode (NFTSM) and the novel reaching law. It is demonstrated that the controller is capable of achieving convergence of the tracking error to zero within a finite time frame. The simulation outcomes substantiate the efficacy of the proposed control methodology, particularly in mitigating chattering.

Consensus problems of mixed-order multi-agent systems composed of first-order agents and second-order agents with directed network topologies are considered in this paper. Firstly, a linear filter is applied to the second-order agents in the systems. Secondly, two consensus protocols are designed by using graph theory, matrix theory, and control theory. Finally, numerical simulation is brought to verify.

Consensus problems of heterogeneous multi-agent systems (MASs) composed of second-order agents and third- order agents with directed network topologies are considered in this paper. Firstly, linear filters are applied to the second-order agents and the third-order agents respectively in the systems. Secondly, two consensus protocols are designed by means of graph theory, matrix theory and control theory. Finally, numerical simulation is brought to verify.