Ritelli, G. and Vacca, A., "Energy Saving Potentials of a Novel Electro-Hydraulic Method to Reduce Oscillations in Fluid Power Machines: The Case of a Hydraulic Crane," SAE Int. J. Commer. Veh. 6(2):269-280, 2013, doi:10.4271/2013-01-2345.
A common issue of many hydraulic machines is given by oscillatory behavior. This is a stringent problem of several load holding machines, such as the case of the hydraulic crane taken as reference in this study. Several methods are traditionally used to dampen these oscillations to reduce hazards and improve productivity. However, these methods are often highly energy dissipative. As pertain to the case of hydraulic cranes, a good dynamic behavior is usually obtained through high energy losses introduced by the counterbalance valves. These valves, which use is often mandatory for load handling applications, are known to introduce oscillatory behavior in the machine actuators. However, these valves can also mitigate the machine dynamics when proper but energy dissipative settings are utilized. This study experimentally evaluates the energy amount saved when more energy efficient valve settings are used. The dynamic response is shown to be greatly affected by these changes.The authors' research team has recently developed an innovative electro-hydraulic method that offers an alternative and model-free way for reducing actuator oscillations. This study experimentally verifies the advantages, in terms of potential energy saving, related to the application of such technique to the case taken as reference.The experiments presented show how for a realistic operation of the crane with a more energy convenient settings of the counterbalance valve it is possible to drastically reduce the overall energy consumption up to 34%, without compromising the dynamic behavior of the machine, if the novel control technique is utilized.