An energy-efficient high performance motion control of a hydraulic crane applying virtual decomposition control

Hydraulic actuators are well-known for their high power-to-weight ratio, rapid responses, compactness and reliable performance. However, one of the drawbacks of fluid power systems have been large energy losses. In this paper, our research objective is to develop both energy-efficient and high performance motion controller for heavy-duty hydraulic manipulators. We apply an unconventional Servo Meter-In Meter-Out (SMIMO) hydraulic valve control setup that is used to decouple hydraulic actuator load pressure level from load force to improve energy efficiency. The developed control system is based on the Virtual Decomposition Control (VDC) approach to guarantee the closed-loop system stability of the multi degree of freedom heavy-duty hydraulic crane driven by the proposed novel SMIMO VDC controller. Capability for approximately 42% lower energy consumption was achieved in the Cartesian motion trajectory experiments with the proposed novel controller compared with a conventional 4-way servo valve setup, without significant control performance deterioration.