Digital hydraulics is one of promising technologies having a huge potential to significantly improve energy efficiency in the fluid power industry. In this paper, we present a digital hydraulics solution for mobile market with a large ammount of energy usage by hydraulic components and systems. Specifically, a novel hydraulic architecture, Multiplex Digital Valve (MDV) system that employs digital valves to meet multiple service pressure/flow requirement in off highway vehicles, is introduced. With MDV being integrated in an execavator, signficant hydraulic power saving have been validated compared to the baseline machine with the negative flow control (NFC) architecture. In addition, considering noise is still a critical hurdle for digital hydraulics to be adoped, we develop several noise reduction methods that have been evaluated in simulation environment and implemented in the above MDV. The sound pressure measured from the retrofitted MDV solution with the NVH treatment in the excavator has been improved signficantly over the untreated system such that it is nearly comparable to the baseline machine. The paper also briefly presents the sound quality study for better understanding of human perception and acceptance to nonconventional sound.

Digital hydraulics is one of promising technologies having a huge potential to significantly improve energy efficiency in the fluid power industry. In this paper, we present a digital hydraulics solution for mobile market with a large ammount of energy usage by hydraulic components and systems. Specifically, a novel hydraulic architecture, Multiplex Digital Valve (MDV) system that employs digital valves to meet multiple service pressure/flow requirement in off highway vehicles, is introduced. With MDV being integrated in an execavator, signficant hydraulic power saving have been validated compared to the baseline machine with the negative flow control (NFC) architecture. In addition, considering noise is still a critical hurdle for digital hydraulics to be adoped, we develop several noise reduction methods that have been evaluated in simulation environment and implemented in the above MDV. The sound pressure measured from the retrofitted MDV solution with the NVH treatment in the excavator has been improved signficantly over the untreated system such that it is nearly comparable to the baseline machine. The paper also briefly presents the sound quality study for better understanding of human perception and acceptance to nonconventional sound.