Matlabr and Simulink Use in Response Analysis of Automobile Suspension System in Design

Abtract In designing automobile suspension, response analysis is an important tool. In this paper, the response analysis of the auto suspension to various road conditions is studied using MATLABR tools and SIMULINK. The suspension system was modeled as a combination of dashpot and spring system in parallel attached to the auto body. Laplace transforms were used in obtaining transfer functions from the ordinary differential equations which described the system. The system, a second order open loop with a unity feed back ‘type 1’system was subjected to different inputs and the response was studied using Matlab inbuilt commands and SIMULINK. The system was observed to be stable to frequency input using the Nyquist diagram. Very fast settling time was observed for the responses. It was observed that it was much easier to design compensators for the system using the Matlab commands. Using MATLAB root locus plot, the system could be re-designed by choosing new locus points and the new gains and damping ratios could be obtained. With the rlocfind command, the gains in the graphics window and the damping ratio could be found as well. With this a better design of the system could be obtained by compensating the system. This brings a dynamism into the design system.