SEDGHI Babak, LONGCHAMP Roland
Stick-slip actuators, also referred to as inertial drives, represent a new technology used for positioning in micro-manipulators. The inertial drive under study is a prototype that is constructed in order to study the stick-slip phenomena in a friction driven system. The advantage of such a system is that the movement range needed by the piezo actuator is much smaller than the movement range of the inertial mass (M). The friction between the small mass (m) and the inertial mass (M) is used to transfer the force generated by piezo actuator to the inertial mass. Using the two structure friction model (e.g. Karnopp model) the system can be considered as a hybrid system. Depending on the external force and relative velocity of two masses distinct operational modes can be distinguished: If the force acting at their interface due to an external input, does not exceed the Coulomb friction level the two masses move together (mode stick). As soon as the Coulomb friction level is exceeded, one mass slips over the other (mode slip). Analysis and control of the inertial drive in the context of hybrid systems are the main goals of this project.
Sedghi B., B. Srinivasan and R. Longchamp. Control of Hybrid Systems via Dehybridization. IEEE ACC, Anchorage, Alaska, USA (May 2002), 692-697
Srinivasan B., B. Sedghi and D. Bonvin. Characterization of the Optimal Solution for a Class of Hybrid Systems. European Control Conference, Porto, Portugal (September 4-7, 2001), 1455-1460