Gaining control of damping

Strong nonlinearities of hydraulic systems and the unpredictable operating conditions of the specific application (e.g., uneven ground, varying loads) are the main challenges to the development of satisfactory general vibration damping methods and controls.

Mobile hydraulic machines are typically affected by vibrations of the machine structure that have to be controlled to improve operator's comfort, machine life, and controllability. Moreover, international standards regulate the permissible vibration level for the operator's health protection.

Vibrations arise from several features of the system dynamics, such as: oil compressibility, hose compliance, and discontinuous functioning of some components (hydraulic domain); mechanical structure elasticity, end-stops, and static friction (mechanical domain); and particular boundary conditions dependent on specific applications (e.g., handling of hanging load, drive on uneven ground). Those systems' features highlight the main challenges of their vibration damping, namely the nonlinear nature of hydraulic and mechanical systems as well as the unpredictable features of boundary conditions.