Thanapat WanichanonChayada ThidrasameeThana PornrattanaprasertPalita MahachotikulMahidol University2020-12-282020-12-282020-01-01International Journal of GEOMATE. Vol.19, No.76 (2020), 110-117218629822-s2.0-85097397394https://repository.li.mahidol.ac.th/handle/123456789/60362© Int. J. of GEOMATE. All rights reserved, including the making of copies unless permission is obtained from the copyright proprietors. A car suspension system is widely applied as it provides a smooth ride and steering stability. With its usefulness, developments and creations of new suspensions are being continuously conducted. This results in drivers and passengers having a better experience when driving on rough roads. In this study, an active suspension is developed by analyzing a working process of a car suspension using the fundamental equations of constrained motion and Lyapunov Theory. MATLAB software is used to analyze the data and to examine the accuracy of the results. The results obtained from the analyzing process were found to be satisfactory. The research is conducted according to the objectives and limitations of the study which are successful in finding a mathematical model for the controller design of an active suspension system. Analyzing the functions of the controller, it was found that spring constant of choke, spring constant of tire, and damping constant affect the smoothness of a car suspension system.Mahidol UniversityAgricultural and Biological SciencesEarth and Planetary SciencesEngineeringEnvironmental ScienceArticleSCOPUS10.21660/2020.76.9339