Investigating the Effective Parameters on Vehicle Stability and Multi-objective Optimization of its Dynamic Indices

Rollover which causes a large number of deaths and pecuniary damages is one of the basic challenges in vehicle safety. If we can decrease the possibility of rollover in some conditions, probably other important indices are decreased like vehicle stability. It means that some indices are improved through the change of parameters but some of them are not. For this reason, to improve rollover and stability indices simultaneously, combined Topsis-Taguchi and Shannon Entropy methods were used in this paper. First, a whole vehicle as a dynamic model was chosen and to verify the most important parameters, 13 parameters in 3 levels including geometric and volumetric parameters were verified. 27 series of tests through the Taguchi method in Minitab software were prepared and evaluated in Carsim software for obtaining rolling angles and yaw rate around the Z axle. The six most important parameters in the previous level were distinguished and again 25 tests were conducted through the Taguchi method in 5 stages in Carsim Software and multi-objective optimization was conducted. Results showed the suggested method in 80km/h made rollover index, rolling angle, lateral acceleration, and yaw rate around Z axle be decreased as %28.9, %26.2, %0.3, %0.2, respectively. Again, the tests were conducted at different speeds and it was found that with increasing speed, the improvement percentage of all indicators decreases.