This article presents a novel design algorithm for the cooperative source-seeking problem using a group of quadrotors equipped with sensors for source scalar field measurement with limited communications. The main objective is to drive the average position state of quadrotors to the optimal point of a given scalar field function while maintaining the desired formation, based on the field value measured by each quadrotor. To achieve this objective, the formation-based source-seeking algorithm is proposed with a cascade structure and the consensus filter, which is composed of a formation controller and a gradient-free optimization algorithm: the formation controller implements the desired formation and provides optimization direction information for the optimization algorithm, while the optimization algorithm generates a movement direction to guide the average position state of quadrotors collectively moving toward the source without estimating gradient, and the consensus filters estimate the centralized quantities. The Lyapunov stability analysis and invariancelike theorem are applied to establish the convergence and robustness of quadrotors’ positions and velocities to the formation and the average position to the optimal point. Finally, the effectiveness of the proposed method is illustrated by a physical experiment and a numerical simulation.

This article presents a novel design algorithm for the cooperative formation control of multirotors with directed and switching topology. A key strategy is to transform the formation control problem into an output agreement problem for which a class of cooperative controllers with successive loops is developed to achieve output agreement. For practical implementation, velocities and accelerations of the controlled multirotors are restricted to within desired ranges by introducing appropriate saturations to the loops. It is proved that each controlled multirotor admits an invariant set property, and the formation control objective can be achieved if a mild joint connectivity condition is satisfied by the switching topology. Along the way, this article also proves a result of independent interest in the output agreement problem subject to both velocity and control input constraints with switching topology. Numerical simulations and physical experiments are employed to verify the effectiveness of the proposed design.

This article presents the input-to-state stability (ISS) and decentralized sliding-mode control of polynomial fuzzy interconnected systems by using the small-gain theorem. The contribution of this article is threefold. First, based on the boundedness of the solution of fuzzy interconnected subsystems, the sufficient conditions for the boundedness fuzzy interconnected system are provided. Second, the ISS small-gain theorem is extended to the polynomial fuzzy interconnected system for the number of membership functions being the same and different, and the trajectory-based ISS small-gain theorem is proposed. Third, the sliding surface based on state feedback is designed, and the stability of sliding-mode motion is analyzed for the fuzzy interconnected system. Finally, the effectiveness and superiority of the proposed method are illustrated by using a numerical example, a spring-connected double inverted pendulum system, and comparison with the existing results.

The coordinated formation control of wheeled mobile robots (WMRs) with directed and switching communication topologies is studied. In particular, together with the non‐holonomic constraint, physical constraints on the velocity, acceleration and angular velocity are taken into account. Through dynamic feedback linearisation, the kinematic model of each robot is transformed into a double‐integrator subject to the physical constraints. Then, coordinated controllers with successive loops are developed for the formation control. The problem caused by the physical constraints is solved by introducing saturations to the control loops. It is proved that each controlled WMR admits an invariant set property, and the formation control objective is achievable as long as a mild joint connectivity condition is satisfied by the communication topology.

This paper investigates the robust formation problem of a class of nonholonomic mobile robots that are controlled by pulse-width-modulation (PWM) signals and subject to switching topologies and measurement disturbances. However, the existing literature does not fully account for the impact of hybrid PWM control inputs and second-order dynamics. As a result, traditional continuous linear control schemes require significant modification before application. To address this problem, a new class of distributed robust PWM controllers is proposed, ensuring that each PWM-controlled agent asymptotically converges to the desired position and velocity. Additionally, an invariant set-like method is presented that restricts the states of each subsystem to a chosen closed set by analyzing the dynamic relationship between the interactions, as long as the information exchange topology satisfies a mild restriction. Finally, it is demonstrated that by analyzing the dynamic relationship between the interactions of different agents, the closed-loop system converges in the sense of input-to-state stability (ISS). A numerical example is provided to validate the theoretical results.