Fluid and Mechanical Engineering Systems Control and Design

Fluid power has transformed from a technology of mere power transmission into an interface technology of great importance. When translating electronic information into action in mechanical systems, the only practical possibility is using electric motors or fluid power, where fluid power must be used when higher performance is required. A long lasting theme within the research group has been an effort to describe hydraulic system dynamics in a unified way.

The research efforts in hydraulic system theory has filled a need in the industry caused by the fact that the hydraulic industry stems from the tradition of mechanical engineering and that dynamic phenomena has been considered as insignificant, or too difficult to deal with, until the last decades. Now the need for more efficient high performance systems has focused the attention on dynamics, to a point where an understanding of the system dynamics has become essential for the implementation of modern systems such as load-sensing systems and hydrostatic transmissions.

As a result of the research carried out by this group, a wide range of dynamic phenomena in complex hydraulic systems have been explained analytically within a unified framework. Furthermore this understanding has been brought out to industry through the close links established between the group and the fluid power industry. The research has also resulted in new hydraulic components, such as the Valvistor, which is a flow amplifier. Further, measurement methods necessary to apply rapid prototyping methods in the design process have been developed.

Projects

In progress

• Energy efficient wheel loader hydraulics
• Energy efficient mobile hydraulics
• Selection schemes and neural networks in adaptive real-time control - predictive simulation adaptive control

Finished

Valve technology

• The Valvistor - a proportionally controlled seat valve
• Experimental methods in valve characteristics assessment
• Valve controlled fluid power systems - flow amplifier and percussive rock drilling
• Conceptual design of hydraulic systems for automotive engine applications - simulation, optimisation and testing
• Hydraulic power steering in passenger cars - analysis, modelling and new functionality

Hydrostatic transmission technology

• Secondary controlled hydraulic systems
• Performance optimization and digital control of hydrostatic drives for vehicle applications
• Hydrostatic transmission control - design methodology for vehicular drivetrain applications

Page responsible: bjorn.eriksson@liu.se
Last updated: 2009-12-14