• identification
• inverse dynamics
• nonlinear control
• optimization
• robot flexibility
• zero dynamics

The requirement of keeping robot structure light while at the same time ensuring high performance is a challenging task in industry. Most of the times, flexibility arises as limiting feature, and control schemes must someway include it to obtain satisfactory results. Usually, flexibility can be due to two different sources: i) joint elasticity, originating from the use of harmonic drives, belts or long shafts as reduction or transmission elements or ii) link flexibility, due to the robot structure itself.
The objective of this thesis is the design of a control law to improve the positioning performance of a SCARA manipulator, subject to end-motion vibrations. Joint elasticity, as well as structural flexibility, have been taken into account to generate a feedforward action based on the inverse dynamics resolution. The control law has been implemented and experimentally tested after modeling the SCARA and identifying its flexible parameters.