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| dc.contributor.author | Melkam, Mengistu | |
| dc.date.accessioned | 2023-12-28T07:05:06Z | |
| dc.date.available | 2023-12-28T07:05:06Z | |
| dc.date.issued | 2023-03 | |
| dc.identifier.uri | http://ir.bdu.edu.et/handle/123456789/15559 | |
| dc.description.abstract | Aircraft technology has transformed human life by enabling regional and international transportation of people and goods. Pitch, Roll, and Yaw are the three basic control motions of an aircraft. In this thesis, we compared the performance of a linear quadratic regulator, a sliding mode, and a super-twisting sliding mode controller for an aircraft pitch control system. The dynamic modeling of a pitch control system is taken into account in the design of an autopilot that controls an aircraft’s pitch angle. It begins with the development of an appropriate mathematical model to depict the longitudinal motion of an aircraft. The nonlinear model of the longitudinal dynamics was linearized based on small disturbance theory by considering cruise phase of flight. The pitch angle is considered as an output and the elevator deflection angle as a control input of the system. Evaluating the model with specified system parameters, the controllers are designed based on the developed dynamic model. In the case of a linear quadratic regulator, which is an optimal controller, a MATLAB function is used to get the gains by selecting state and control matrices. For sliding mode and super-twisting sliding mode controllers, genetic algorithm optimization is used to tune the control parameters. The designed controllers were simulated with MATLAB/Simulink. The simulation result shows that the super-twisting sliding mode controller produces a response time of 0.3426 sec to rise and 0.5605 sec to settle with no overshoot and steady-state error. The sliding mode controller results in a response time of 0.3666 sec to rise and 0.7315 sec to settle with no overshoot and steady-state error. And a linear quadratic regulator with a response time of 0.5758 sec to rise and 1.6045 sec to settle, an overshoot of 2.8672% and steady state error of 0.0034%. The super-twisting sliding mode and the sliding mode controllers show robustness to the change in parameters based on simulation results on robustness analysis. Our result indicates that the proposed controllers in this thesis perform within the design requirements. However, the super-twisting sliding mode controller performs better for aircraft pitch control by avoiding the chattering effect, being robust, and giving a fast response. Key words: Aircraft pitch control, Genetic algorithm, Linear Quadratic Regulator, Longitudinal dynamics, Sliding mode controller, Super-Twisting sliding mode controller | en_US |
| dc.language.iso | en_US | en_US |
| dc.subject | Electrical and Computer Engineering | en_US |
| dc.title | Comparative Analysis of LQR, SMC and ST-SMC for Aircraft Pitch Control System | en_US |
| dc.type | Thesis | en_US |
