Volvo Construction Equipment is working with Norrhydro on the development of a digital hydraulic actuator technology for use in excavators to help improve fuel efficiency. Kim Heybroek, Research Engineer at Volvo Construction Equipment, says that at a high level, the new actuator technology works like other linear actuators in the market in that it controls force and the speed of individual drives such as boom and arm functions of an excavator. However, compared to a normal double-acting cylinder drive, this actuator is comprised of a mechanical cylinder and several electronically controlled valves as well as an ECU with a software control interface which controls the valves with feedback from sensors found within the actuator. Based on this feedback, the actuator force and velocity are controlled in a closed loop fashion. Once integrated into a machine like an excavator, a new type of hydraulics system can be developed which overcomes many of the shortcomings of traditional systems to help improve machine performance and efficiency.