Multivariable control for reference tracking on half car test rig

The multivariable tracking accuracy on an automotive vibration test rig can be improved by extending the current industrial off-line iterative feedforward procedure with a real time feedback controller. This paper compares two MIMO feedback controller design procedures in practice. First DK-iteration is used. This is the most common μ-synthesis method to design robust MIMO-controllers. Secondly a controller based on decoupling design is tested. This is a two step procedure. Step one is the calculation of a transformation of the inputs and the outputs to decouple the system as accurately as possible. Step two is the design of a decentralized controller (combination of independent SISO-controllers) for the transformed system. While the control design based on decoupling, using standard SISO H∞techniques is much simpler and more straightforward, the performance is comparable to that of the controller based on μ-synthesis.