مجيد جغتايي

This thesis investigates an‎d models a vehicle air suspension system. This system is a crucial component for enhancing passenger comfort an‎d improving vehicle stability on various road surfaces. In this research, the modeling of the air suspension system was initially conducted using pneumatic an‎d dynamic models. The pneumatic model describes the behavior of the fluid within the air suspension system, while the dynamic model describes the vehicleʹs dynamic behavior, such as changes in the center of mass height an‎d roll/pitch angles. Furthermore, to more clearly illustrate the physical structure an‎d layout of the pneumatic cylinders, the system was designed using the specialized FluidSim software. For system simulation, the pneumatic-dynamic equations of the system were derived. By defining state variables, the state-space matrices were calculated, an‎d the complete vehicle system was simulated in the MATLAB an‎d Simulink environment. Subsequently, given the interconnected air suspension system, various interconnection modes lateral, longitudinal, an‎d cross (four-corner) were examined an‎d modeled. For each of these modes, multiple simulations were performed to analyze the performance of the air suspension system under different road conditions, taking road disturbances into account. In the second part of the research, an LQR (Linear Quadratic Regulator) controller was designed an‎d simulated for the air suspension system to improve its performance an‎d reduce road-induced disturbances. Brysonʹs rule was applied for optimization, an‎d using the optimized Brysonʹs rule, the controllerʹs weighting coefficients were determined, an‎d its performance was eva‎luated under various conditions. The obtained results demonstrate that the interconnected air suspension system with the designed controller can achieve superior performance compared to non-interconnected an‎d passive air suspension systems, thereby enhancing both stability an‎d passenger comfort.

سيستم تعليق بادي , كنترل سلسله مراتبي , سيستم تعليق به‌هم‌متصل

Air suspension system , Hierarchical Control , Interconnected suspension system

Majid Jaghtaei

Dr. Masuod Masih Tehrani