Integrated fluid power research focuses on energy efficiency, covering a broad spectrum in the areas of control, component and systems development and energy management. Topics of interest include hybrid systems, electro-hydraulic and other autonomous actuators and energy management.  Energy management is focused on regenerative systems in general, using external and renewable energy, enhanced pressure accumulators, pumps, and compressors. Also new manufacturing technologies such as additive manufacturing are utilized. As fluid power technology is tightly integrated with other technologies, such as electronics, mechanics and thermodynamics, these aspects are also considered in most research. Therefore, multi-physics systems and entire machine systems are simulated as well as Hardware-in-the-Loop (HIL) systems consisting of real and virtual components. Electrification of mobile machinery is advancing and because of limited battery capacity, high energy efficiency is demanded of all the power consuming sub-systems including fluid power systems.

Electro-hydraulic actuators are self-contained, integrated devices typically utilizing good dynamics and high energy efficiency of electric servomotors. When connected to advanced hydraulic pumps direct control of actuators can be achieved without the need to use additional fluid flow throttling valves. The performance especially related to energy efficiency is unique compared with traditional systems controlled by using proportional valves. This is partly because potential and kinetic energy can be utilized for efficient energy recovery. 

Hybrid systems enable using different kinds of energy sources, thus improving their energy economics. The research focuses on self-contained actuators, which are expected to replace the central hydraulic systems in many industrial and mobile machines. Hybrid systems include self-sufficiency, fewer design constraints, an optimized selection of components, enhanced energy-efficiency, and better maintainability.

Vibration control of machines can effectively utilize fluid power systems to reduce oscillations and enable enhanced performance, such as higher rotational speeds. Other benefits are reduced wear, maintenance, and prolonged lifetime. In working machines, actuator seal friction control enables improved boom motion smoothness and accuracy. Actuators’ damping and stiffness can be controlled to optimize whole machine’s oscillation response. Passive, semi-active and active fluid power devices belong to the studied approaches.

Energy management and efficiency research is focused on regenerative systems in general, using external and renewable energy, novel pressure accumulator designs, multi-quadrant pumps, and exploiting new manufacturing technologies in prototype development. The need for energy-efficient systems is increasing due to the rapid increase in global energy usage and risks posed by global warming.

Aalto Fluid Power Laboratory
Sähkömiehentie 4 O
02150 Espoo