Development of electro-hydraulic actuators using linked simulation and hardware-in-the-loop technology

Even today the development and optimisation of active control using fluid-power transmission and motion control technology is a comparatively complex problem that requires a relatively large amount of experimental testing and optimisation. Some reasons are: complex interactions between actuator and active controlled structure, the vital influence on system behaviour by the electro-hydraulic actuator itself and last but not least a relatively low natural damping of the actuator. The design of electro- hydraulic active vibration control is to a large extent still based on the experience of the involved staff of the design and test departments as well as on a time- and cost-intensive development work that often produces a good solution only if iterations are performed, Growing demands for shortened development and start-up times and for a reduced development risk as well as the desire for secure predictions of static and dynamic properties require that this situation should be improved. An important means is numerical simulation. In a research project performed by Institute of Fluid Power and motion control in close cooperation with the Institute of Theoretical Fundamentials of Vehicle Engineering, a linked mechanic and hydraulic simulation was developed in combination of hardware-in-the-loop test facility. Nonlinearity's of the components are considered, reproducible test runs in the test laboratory offer profitable optimisation possibilities in an early stage of development. The expenditure involved in the preparation of prototypes is minimised because of the reduced number of prototype test cycles needed which also results in shorter system development times.