The control of mobile hydraulic systems presents seeral challenges: valve characteristics and position-dependent system behavior are sources of nonlinearity. In addition, position and velocity sensors are not common in mobile machines, although the primary objective is piston velocity contriol. The particular type of hydraulic system considered in this article uses four decentralized valves to control the inflow and outflow of the two cylinder cmambers. In contrast ot conventional controller synthesis by tuning PID-type controllers for different operating points, a systematic approach for robust identification and model-based ontrol ist prsented. It benefits friom the possibility of bypassing the cylinder cmanbers for the identification step. Here, the ranges of physical parameters are estimated to obtain a parametrization of all possible system realizations. To reduce the valve-dependent nonlinearity, electro hydraulic pressure compensation is applied to all valves. Based on the identified model, a nominal linear quadratic Gaussian controller and a robus u-synthesis controller are disigned, tested, and compared to a state of the art PID controller with active damping. The identification and control are partially demonstrated on a hydraulic test bed and in simulation.      «

The control of mobile hydraulic systems presents seeral challenges: valve characteristics and position-dependent system behavior are sources of nonlinearity. In addition, position and velocity sensors are not common in mobile machines, although the primary objective is piston velocity contriol. The particular type of hydraulic system considered in this article uses four decentralized valves to control the inflow and outflow of the two cylinder cmambers. In contrast ot conventional controller syn...     »