Abstract
In mobile machinery powered by hydraulics, such as cranes and excavators there is much oscillation in the mechanical structure of the machine if the controls are not handled very gentle by the operator.
Reducing the oscillations reduces the dynamic loads on the machine, which means that a crane can be rated for higher loads. In an excavator the operator will be exposed to less vibrations and since the operator will not have to be so careful with the controls, productivity will increase.
This paper explores two different methods to introduce damping in mobile systems. First, the very simple yet very powerful method of pressure feed back with guide function is discussed. Second, the method of, identification on-line and pressure feedback from an observer is discussed.
