Application or a hydropneumaiic boom support system with controlled stiffness and dissipation parameters in a crane in its ready-for-transport position allows for modification of dynamic properties or the crane and for vibration mode control during the ride. Adjusting the support system llexibility to disturbances being the result of uneven terrain may heir to reduce the loading of the bearing structure and to increase speed still maintaining the required safety and comfort standards. That improves the functional quality of mobile machines. The results of this study may be used as the basis for evaluation 01· vibration control methods in mobile cranes in which the boom acts as a dynamic absorber.

Vibration intensity in mobile machines depends on the road roughness profile, ride velocity and dissipative properties of machine components. To reduce vibrations of a mobile machine with a boom equipment one of the available passive methods, utilizing a hydropnematic system for boom support to improve flexibility, the system incorporating throttling valves. Energy dissipation in a hydropneumatic system controls the decay of vibrations of the machine body and equipment. In the range of large velocities, passive methods prove inadequate. When ride velocity is to be increased, at the same time the required safety features and stabilization of the position of machine equipment are to be provided, further dynamic analyses are fully merited to identify processes taking place in the driving system. The final result should be the synthesis of the LQR control system to modulate the loading characteristics of the motor and to control the flow in a hydraulic boom-support system.