Oscillation and Vibration Reduction Approaches on a HiL-Steering-Test-Bench

Within the automotive development process hardware-in-the-loop steering test benches are utilized to reduce the number of vehicle prototypes and the necessary amount of full vehicle testing. Since electromechanical power steering systems are active components, equipped with their individual control strategy, the control of the test bench in combination with the electromechanical power steering system is a demanding task in regards of control accuracy and stability. Still, it is possible, that software releases, which run stably in the vehicle, show vibrations on a test bench. This article implements two methods to reduce the occurring vibrations on a steering test bench. The first method utilizes a virtual passive absorber technique to suppress oscillations close to the natural frequency of the system. A second approach implements a damping connection joint (DCJ) in the force path between the linear actuator and the steering system. Since the damping characteristic can only be implemented in parallel with an elastic component, an elasticity compensation model is parameterized and implemented in the control scheme to account for relative displacement within the DCJ. Together with the DCJ, it is called the DCJ with compensation. Final experiments on a steering test bench demonstrate the performance of the strategies for oscillation suppression as well as the comparability of the obtained data from a rigidly connected steering system.