Real-Time LQG Control Strategies for Electrohydraulic Steering of Mobile Machines

The main aim of the article is to compare two real-time control strategies for electrohydraulic power steering system of modern mobile machines with Linear-quadratic Gaussian (LQG) controllers. The both modification of LQG controller are designed on the basis of two multivariable uncertain plant models. The plant models are obtained by identification procedure via "black box" approach and takes into account the deviations of the parameters that characterize the way that the control signal acts on the state of the models. The difference between the two modifications of the embedded controllers lies in the different types of output signals, which are used as feedback in control system. The comparative analysis of time and frequency domain properties of controllers are performed. The results obtained show the better performance of one system. The control algorithms are implemented in 32-bit microcontroller. A number of experiments have been executed, which confirm the quality of the electrohydraulic power steering control system.