The active damping of vibration of a system can be accomplished by a force sensor and a controlled linear actuator. Linear electromechanical actuators based on recirculating ballscrew system and actuated by brushless servomotor are promising candidates in the range 10-100 KN and 20-50Hz, with respect to hydraulic or piezoelectric systems. Ballscrew actuators show smaller envelope and weigh less, with fewer environmental issues with respect to hydraulic systems, and less critical thermal and electric current concern with respect to piezoelectric systems. The demanding requirements of weight, power and envelope can be accomplished by a patented design invented by Umbra Cuscinetti, with a small equivalent thread pitch, but ball diameter not limited by pitch. In order to fully exploit this configuration, a multi-objective optimization tool, that can examine several thousands of different designs, with an optimization strategy based on a genetic algorithm, has been used. Starting from few feasible designs, the optimization software modeFRONTIER can handle both proprietary codes and commercial software, in order to exploit all the needed disciplines (structures, dynamics, electromagnetic, etc.) and run the optimization strategy. From the initial design, that does not fit the envelope, after optimization the overall size goal is reached, with a mass reduction of 16% and a power consumption of 5% less than the design initially found. The best optimization strategy is a genetic adaptive algorithm. |
22-23 October 2012 Pacengo del Garda 
