Analyse and Optimise on Active Suspension System of Automobile

Siow, Kai Loon (2025) Analyse and Optimise on Active Suspension System of Automobile. Final Year Project (Bachelor), Tunku Abdul Rahman University of Management and Technology.

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Abstract

This project presents a comprehensive study on the modeling, simulation, and optimisation of an active suspension system using a half-car model to enhance vehicle ride comfort and handling performance. In modern automotive design, suspension systems play a critical role in isolating the vehicle body from road irregularities and maintaining tire contact with the road surface. To address the limitations of passive suspension systems, which lack adaptability under varying driving conditions, this research proposes the use of a Proportional-Integral-Derivative (PID) controller as a control strategy for active suspension. The half-car model is adopted in this project due to its ability to accurately represent both vertical and rotational dynamics of the vehicle, including front and rear suspension interactions and pitch motion. Half-car model provides a more realistic simulation environment compared to the quarter-car model, allowing for the evaluation of ride quality as well as pitch stability, which are essential for longitudinal dynamic control during acceleration and braking. The dynamic equations of motion are formulated and implemented in MATLAB Simulink to simulate the system response under varying road conditions. Static structural analysis using ANSYS is also conducted to verify the mechanical strength of key suspension components. Initial PID parameters are manually tuned, and subsequent optimisation is carried out by adjusting the controller gains to balance system responsiveness and stability. The simulation is performed under a controlled scenario with a road bump height of 0.2 meters and a vehicle speed of 20 kilometers per hour. Results show that the optimised PID controller significantly reduces peak body displacement, improves settling time, and minimises oscillations compared to both passive and initial PID-controlled systems. The findings confirmthe effectiveness of active suspension systems in enhancing vehicle dynamics, validating the use of a well-tuned PID controller as a practical solution for modern suspension design.