Tez özetleri Astronomi ve Uzay Bilimleri Anabilim Dalı

Adaptive Control of Vehicle Suspension Systems
The aim of this work, firstly, is to demonstrate the applicability of a novel approach ‘Model Reaching Adaptive Control’ for active vibration isolation systems in the literature to the vehicle active suspension systems. Subsequently, in order to increase the robustness of the system by providing an additional control input to the known adaptive law, a new parameter adaptation algorithm has been developed and the stability of the system has been guaranteed by using the Lyapunov method.

The mechanical vibrations on the vehicle suspension systems which are caused by the road disturbances, discomfort people in terms of vehicle driving safety and ride comfort. Also reduce the mechanical life of the vehicle parts. For this reason, these vibrations should be minimized as much as possible.

In order to solve this engineering problem firstly, the vehicle which is modeled as a quarter car has exposed to a sinusoidal road input which is frequently encountered on the roads. In terms of the success of reaching the identified target dynamic as ideal skyhook, the detailed analysis of both known adaptive control and proposed adaptive control has been done. In the second stage, it is aimed that the vehicle which exposed to same road input, to reach another ideal skyhook dynamics with different damping and stiffness characteristics.

Afterwards, the vehicle has exposed to road disturbance consisting of two bumps with different heights. It is aimed to reach another ideal skyhook dynamics with different damping and stiffness characteristics, here as well. Interpreting the findings, the issues of vehicle driving safety and ride comfort have been emphasized.

Finally, simulations with ramp road input have been made and the effect of the adaptive controller to the consequences which occured as a result of this road disturbance has been discussed.

The success of applied controllers at different road conditions and different dynamics has been interpreted for each four systems by using computer simulations.

Time and frequency responses of the system show that the known adaptive controller is successfully applied to the quarter car active suspension system. With the development of the known adaptive controller, values ​​of the vibration and damping time have been significantly reduced, the better results has been observed on the same terms with the developed adaptive controller. While it is required the higher control parameters ​​for vibration damping with the known adaptive controller, these higher parameters have been significantly reduced with the proposed adaptive controller.