Abstract
KEYWORDS - ECS (Electronically Controlled Suspension), Road Roughness, Optimal Control, Kalman Filter, DWF (Dynamic Wheel Force)
ABSTRACT –
Semi-active Electronically Controlled Suspension (ECS) has been researched and developed in order to improve vehicle ride comfort and handling performance simultaneously under various road conditions. However, traditional ECS system not only has to be operated in separated modes but also has map based algorithms which requires lots of tuning efforts. Therefore, conventional ECS is not performed optimally under various driving condition or different types of road. We are designing a new control scheme based on 7DOF vehicle model. This control scheme includes Kalman filter for state estimation and LQR control logic for control force calculation. And the control gains are modulated using road roughness measure based on DWF (Dynamic wheel force) value. However this DWF concept for road roughness measure is not suitable in real vehicle. Because it doesn’t show good road-detection performance while crossing into speed bumps and some kinds of impact-like road surfaces. So in this paper, we modify the road detection module, which can skip impact-like small road surfaces and detect speed bumps. Corresponding simple gain scheduling strategy is designed to continuously switch optimal gains for each road in real vehicle environments.