Comparison of heuristic controllers for an automotive semi-active suspension

A comparative analysis between two different heuristic suspension control strategies is presented, the approaches have been designed to control the vertical dynamics of a full size pick-up truck model equipped with Magneto-Rheological (MR) dampers. The control schemes to compare are: (1) a global suspension controller and, (2) four independent controllers, one for each Quarter of Vehicle (QoV) model; both control schemes depend only on measurements. The main idea is to compare the control performances and the implications that these heuristic controllers have. Experimental data are used to model an MR damper in each corner. Two tests have been used to compare the control performances when the vehicle is driven in straight trajectories: (1) a running test on a road based on the standard ISO 8606 and, (2) a road that excites the vertical dynamics at different frequencies (Bounce Sine Sweep test). Results obtained using CarSim™ show that the comfort performance is better when the controller is well coordinated among the wheel-stations (global suspension controller); the improvement is 33% in the heave motion and 35% in the pitch angle. The QoV-based controller presents uncoordination that complicates the attenuation of the vehicle body movement; however, the road holding is improved.