Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits
In this master thesis, a mathematical model of a hydraulic servo system for a manipulator robot
is completed by using several different methodologies. The models proposed are particularly
tuned for the DeLaval VMS robotic arm. The parameter identification of the robotic arm is
accomplished by dividing the model into several subsystems and investigating each system
separately by using catalogue data, experimental data and construction drawings. Furthermore,
the assumptions are proposed based on the literature review and the expertise of in-house
After completion of parameter identification several different mathematical models including
linear and nonlinear methodologies are introduced. It is demonstrated that the improvednonlinear
model can successfully mimic the movement of the robotic arm with relatively small
errors and it is found to be fairly reliable. Moreover, the errors incurred when chamber pressures
are compared with experimental data are found to be relatively small. Furthermore, the improved
linear model have successfully delivered an accurate position estimation especially for the
medium valve opening, while the chamber pressures are relatively less accurately predicted.
The study further carries out sensitivity (uncertainty) analyses to investigate the crucial
parameters of the model since it is sometimes very problematic to precisely estimate these
parameters. It is found out that the flow coefficient and supply pressures have remarkable impact
on the results of the simulations. Therefore, it is strongly advised that these parameters should be
very carefully evaluated during the modeling process.
Finally the bulk modulus models are compared and the influence of the bulk modulus is
2014. , 81 p.