Author :
Samani, Mohammad ; Tafreshi, Mona ; Shafieenejad, Iman ; Nikkhah, Amir Ali
Abstract :
In this research, time-optimal open-loop and closed-loop guidance laws for MAVs, such as Samarai, were investigated. Open-loop optimal solutions were achieved with a new technique,based on using mathematical methods, such as calculus of variation and the GA-PSO optimization algorithm. This novel method could overcome difficulties of the usual optimal control methods. The TS approach developed closed-loop guidance that dealt with the novel neural-fuzzy training algorithm based on open-loop optimal trajectories to achieve closed-loop guidance. By feed forwarding the optimal control as a nominal optimum trajectory plus deviation, closed-loop optimal control can be generated. On the other hand, (TS) fuzzy logic needs storing nominal optimal trajectories to train the system. As discussed, the responses of the optimal closed-loop guidance were achieved, and the robustness of closed-loop policies against noises and/or disturbances was studied. However, it was difficult to obtain closed-loop solutions when the other methods, such as dynamic programming or analytical methods, were considered. The case mentioned is an important innovative idea for autonomous MAVs, whose results are important for further developments of Samarai monocopter. The results of this work demonstrated that the closed-loop optimal responses based on TS fuzzy logic methods can damp disturbances for minimum time criterion. However, the result of fuzzy logic is perfectly suitable, where higher noises were applied. Therefore, it can be concluded that fuzzy logic was robust and efficient in eliminating perturbations. It is proposed that aerospace engineers, such as primary trajectory designers, use TS fuzzy training guidance because its robustness was guaranteed by this work, especially for MAVs, such as Samarai.
Keywords :
autonomous aerial vehicles; closed loop systems; fuzzy control; fuzzy neural nets; genetic algorithms; neurocontrollers; open loop systems; optimal control; particle swarm optimisation; GA-PSO optimization algorithm; Samarai MAV flight; Samarai monocopter; TS approach; TS fuzzy logic methods; TS fuzzy training guidance; analytical methods; autonomous MAVs; closed-loop optimal control method; closed-loop optimal guidance laws; dynamic programming; mathematical methods; minimum time criterion; minimum-time open-loop optimal guidance laws; neural-fuzzy training algorithm; nominal optimum trajectory plus deviation; open-loop optimal trajectory; Fuzzy logic; Optimal control; Optimization; Remotely operated vehicles; Robustness; Unmanned aerial vehicles; Vehicle dynamics;