Efficiency of On-Off Semiactive Suspensions in a Pick-up Truck

A comparative analysis between three different semi-active suspension control techniques in a full vehicle model of a pick-up truck is presented. Each independent corner of the vehicle uses a Magneto-Rheological (MR) damper model. The MR damper model includes nonlinearities, hysteresis, and transient response between the manipulation and actuation. The damper model parameters have been obtained from experimental data provided from a BWI™ MR damper. Different tests were used to evaluate the semi-active control strategies by using the CarSim® software. The evaluated controllers, which are based on switching manipulation between the low and high damping force, are: 1) the hybrid controller, 2) Mix 1-sensor (Mix-1) and 3) Frequency Estimation-Based (FEB) controller. These selected controllers share the next features: the use of few sensors, free of models, and they do not require anti-saturation mechanisms. Simulation results showed that the FEB controller had the best performance for passengers comfort in the bounce sine sweep test (9% less of movement in the vehicle body respect to the passive suspension system), and better performance, in conjunction with the Mix-1 controller, for road holding and roll control in the double lane change test. Finally, the FEB and Mix-1 control strategies reduce up to 2 degrees the vehicle slipping in the fishhook test, in comparison to the commercial suspension system of the pick-up truck.