Early success for attempt to model robot milling dynamics

Attempts to find a low cost, rapid method for optimising the operation of robots used for milling are achieving some early successes, researchers attending a technology update at the AMRC's Knowledge Transfer Centre heard.

Research into robot milling as an alternative to large scale CNC machines is becoming increasingly important as demand increases for flexible and reconfigurable manufacturing systems.

However, the static and dynamic deflections affecting robot systems can lead to form errors and poor surface finish, resulting in low productivity.

Omer Faruk Sapmaz, a student from the Mechanical Engineering Department at Gazi University, in the Turkish capital of Ankara, has been working on modelling the dynamics of a hexapod robot, retrofitted with a milling head at the Nuclear AMRC as part of the European Union's Erasmus Internship Mobility Programme.

He outlined how he had used Finite Element Modelling (FEM) to create a series of models of the structural dynamics of the hexapod robot used for mobile machining.

Comparing frequencies predicted by FEM with experimental results showed close correlation with one model scenario in particular.

Future research could include developing the model so that the data is produces could be used to avoid chatter, determine the safest machining position for the robot and predict tool tip Frequency Response Function (FRF).