Traditionally, counterbalance valve (CBV) is widely used to counterbalance negative load of fluid power machinery. CBV introduces extra energy consumption and oscillation to hydraulic system especially for time varying system. The essence of its shortcoming is the inflexibility of the control architecture. In this article, a proportional orifice is adopted to counterbalance negative load, which makes the control strategy flexible. A load observer is proposed to demonstrate the load dynamically. A control algorithm based on back-stepping design is proposed in this paper afterwards, aiming at keeping the inlet chamber pressure of the actuator around a fairy small value. The control error is estimated, as well. A simulation for the process of the excavator booming down is carried out to verify the observer and control algorithm, which proves the energy-saving target achieved.

This content is only available via PDF.
You do not currently have access to this content.