Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : H-infinity control


Optimal H-infinity PID Model Reference Controller Design for Roll Control of a Tail-Sitter VTOL UAV

Ali H. Mhmood; Hazem I. Ali

Engineering and Technology Journal, 2021, Volume 39, Issue 4A, Pages 552-564
DOI: 10.30684/etj.v39i4A.1861

In this work, an optimal and robust controller based on consolidating the PID controller and H-infinity approach with the model reference control is proposed. The proposed controller is intended to accomplish a satisfactory transient response by including the reference model. A Tail-Sitter VTOL UAV system is used to show the effectiveness of the proposed controller. A dynamic model of the system is formulated using Euler method. To optimize the design procedure, the Black Hole Optimization (BHO) method is used as a new Calibration method. The deviation between the reference model output and system output will be minimized to obtain the required specifications. The results indicate that the proposed controller is very powerful in compensating the system parameters variations and in forcing the system output to asymptotically track the output of the reference model.

H-infinity Based Full State Feedback Controller Design for Human Swing Leg

Hazem I. Ali; Azhar J. Abdulridha

Engineering and Technology Journal, 2018, Volume 36, Issue 3A, Pages 350-357
DOI: 10.30684/etj.36.3A.15

In this paper, the robustness properties of H-infinity control to produce a dynamic output feedback controller is applied to a human swing leg system. The double pendulum structure is usually used to model this system. The pendulum links will represent the thigh and shank of a human leg. The upper body will be connected to the thigh and then the shank via hip and knee joints. The muscles of thigh and shank are moved by applied two external (servomotor) torques at the hip and knee joints. The mathematical model of the system is developed. The results show that the proposed controller can robustly stabilize the system and achieve a desirable time response specification. The results are obtained by using Matlab program and the achieved time response specifications are rise time tr=0.18 seconds, settling time ts=0.25 seconds and maximum over shoot Mp=0.03 for hip joint and tr=0.13 seconds, ts=0.21 seconds andMp=0.01 for knee joint.