Stiffness Optimization by Extremum Seeking Control to Realize Energy Saving

In recent years, many types of variable stiffness devices are developed. These devices have an ability to change the stiffness of a mechanical system. They can also store energy thanks to elastic elements, and convert it to kinetic energy. By installing these devices in the mechanical system, it is expected that an actuator’s energy which is required to achieve a periodic motion will be reduced. In this research, we realize on-line stiffness optimization and on-line energy saving by using variable stiffness device and adopting extremum seeking control. Therefore, even if the target motion and parameters of the plant are subject to change, the system can continue to work with a little energy. It was shown by numerical simulation.