The main focus of this research is design and presentation of a suitable, efficient and optimal distributed control protocol to perform the cooperative task assignment of a nonlinear multi-agent system. The multi-agent system chosen for this research is a multi-quadrotor system in which quadrotors are known as nonlinear agents. In addition to the nonlinearity of the dynamics of these agents, coupled dynamics of the quadrotors as well as their underactuated dynamics are other challenges that are considered to this research. The common task that assigned to this multi-quadrutor system is load transportation from an initial point to a target point on a desired path. Formation control is another mission that are discussed in connection with this type of multi-agent systems. In this research, this mission is designed and solved for a multi-agent system with nonlinear and underactuated agents, as quadrotors. By designing a novel distributed control protocol, which is a combination of integrator backstepping controller and sliding mode controller, the formation control problem of this system is solved and by using the stability proof and also performing some simulated problem examples, the effectivness and performance of this protocol is eva‎luated. In addition, another issue, which is assigned a cooperative task to this system, will be discussed in the following. First, a suitable distributed algorithm based on integrator backstepping controller is designed and developed for this system. By using stability proof and solving a simulated numerical problem, the performance of this designed algorithm is validated. Due to the fact that the exact measurement of all the states of this system is very expensive and troublesome, it is better to design and develop another algorithm to carry out the assigned task which is the aerial suspended load transportation. The control algorithm based on the dynamic surface controller is another control algorithm that is designed and developed to solve the problem of carrying a suspended load. This algorithm, which does not suffer from the problem of "explosion of terms" that exists in the design of the control algorithm based on integrator backstepping, can solve the problem of assigning the task of carrying the suspended load by using state estimator. The verification of the good performance of the presented algorithm is done by using stability proof and also solving the simulated problem. In addition, a robust adaptive estimator is designed and presented to estimate the system parameters.

مصطفي غيور , محمد دانش

مهدي كشميري , سعيد بهبهاني , آريا الستي