fuzzy control allocation

In many modern vehicles of the new generation, the utilization of control allocation is an effective method for performing coordinated maneuvers, reducing the energy required for aerial operations, compensating for actuator faults, increasing reliability, and preventing saturation of actuators. This paper focuses on the coordinated control of multiple agents for automatic landing and execution of formation flight using a fuzzy control allocation approach. For executing coordinated flight, the leadership role is assumed by one of the vehicles, known as the leader agent, while the other two vehicles act as follower agents. By using a fuzzy controller and optimizing its parameters with the NSGA-II genetic algorithm and allocating control signals between the lift actuators and the thrust vector control (TVC) system, the agents can be guided to a specified altitude with desirable stability, sufficient accuracy, and minimal control effort, and then perform coordinated and orderly maneuvers. The results show that the fuzzy control allocation method provides high accuracy in controlling the landing of the vehicle to a specified altitude, and ultimately, the vehicle execute the coordinated automatic landing maneuver with suitable conditions, sufficient stability, high accuracy, relatively short time, and minimal control effort.

In modern aircrafts, control allocation is one of the effective methods for executing specific maneuvers, time or energy reduction for determined operation, and compensating of actuators faults. For this purpose, the aircraft should be over-actuated in various channels. In this situation, control allocation means the distribution or division of the required control signals between aerodynamic surfaces (aerodynamic actuators) and the thrust vector control (TVC) system. Among the different approaches for control allocation, the use of methods based on soft computing is of interest. Therefore, the main goal of this article is utilization of fuzzy logic and multi-objective optimization to allocate control signals for the landing phase of the F/A-18 aircraft in the presence of elevator and TVC actuators. Therefore, flight modeling and simulation of aircraft has been done and by defining suitable fuzzy rules and specific objective functions, the ability of the developed allocation approach to converge the output variables to the expected values is demonstrated and finally, the aircraft completes the landing phase with desired accuracy and optimal control effort.