Ride Evaluation of Vehicle Suspension Employing Non-Linear Inerter

Abstract:

Inerter is a recent element in suspension systems with the property that the generated force is proportional to the relative acceleration between its two terminals, which is similar to the way a spring reacts to relative displacement and a damper to relative velocity. This paper presents the analysis of a non-linear inerter working in parallel to passive spring and damper of a vehicle suspension to evaluate its effect on vehicles ride. The non-linear inerter was theoretically capable of switching between on and off states depending on whether or not the suspension deflection was beyond a specified free play. In the study, this behavior was represented mathematically as control law which depended on the relative displacement between the sprung and unsprung masses. A mathematical quarter vehicle model incorporating the non-linear inerter was simulated in MATLAB/Simulink to determine the vehicle responses due to road input in the form of step profile for different combinations of free play and inerters on-state proportionality constant called the inertance. Results showed improvements in vehicle ride comfort, as demonstrated by the lower root-mean-squared sprung mass accelerations compared to the ordinary passive suspension with only spring and damper. Additionally, implementation of non-linear inerter gave lower percentage overshoot to step input, indicating better transient response than ordinary passive suspension.

• Periodical: Applied Mechanics and Materials (Volume 471)
• Pages: 9-13
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.471.9
• Online since: December 2013
• Authors: M.F. Soong, Rahizar Ramli, Wan Nor Liza Wan Mahadi
• Keywords: Inerter, Nonlinear, Quarter Vehicle Model, Ride Comfort, Vehicle Suspension

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