Vibration Analysis of Semi Active Suspension System for an Auto Rickshaw by Using Matlab/simulink

An auto rickshaw is a three wheeled motor vehicle with one front steering wheel. Auto rickshaws are most commonly found in developing countries as they are a very cheap form of transportation due to low price, low maintenance cost, and low operation costs. Auto rickshaws needs to be developed to take the step into the 21-century. To develop a new product in the modern world one of the most important challenges is safety of the users. As for the automotive industries this challenge has a great importance since the outcome can be devastating. One important category from the safety point of view is the vehicle suspensions, as the suspensions control the movement of the wheels and thus keeping the vehicle on the road. Suspension system design is a challenging task for the automobile designers in view of multiple control parameters, complex objectives and stochastic disturbances. The objective of this project is to develop a MATLAB/SIMULINK model of one third auto rickshaw suspension to analyze the ride comfort and vehicle handling. A theoretical model of the human seated model is developed in order to simulate the vertical motion of the Passenger in an auto rickshaw when the vehicle passing over various road disturbances. This project used a new approach in designing the suspension system which is semi-active suspension. The semi active suspension system uses a varying damping force as a control force. Ride comfort of off-road vehicles can be estimated by replacing the normal passive dampers in the vehicle suspension system with controllable, two-state, semi-active dampers. Skyhook controller is developed for controlling the damping force of the suspension system. Comprehensive analysis of passive and semi-active suspension system in terms of human body vibrational displacements and accelerations has been done. The semi-active suspension with skyhook controller reduces the sprung mass acceleration and displacement hence improving the passengers comfort. Keywords—damper, semi active, skyhook,comfort Abbreviations and Acronyms Zse Vertical displacement of the seat, Zs Vertical displacement of the sprung mass, Zu Vertical displacement of the unsprung mass Zr Road displacement M se Masse of the seat, Ms Sprung mass Mu Unsprung mass. K se Spring stiffness of seat Cpse Damping coefficient of seat Cps and Ks Suspension damping and stiffness Kt Tire stiffness.