Magnetic Stiffness of Soft Continuous Permanent Magnet and its Parametric Effects on a Magnetic Series Elastic Actuator Control System
Wenjing Li , Kok-Meng Lee* , Min-Geun Park, and 2 more authors
In 2024 IEEE International Conference on Advanced Intelligent Mechatronics (AIM) , Boston, MA, USA, Jul 2024
This paper presents the design concept of a soft continuous permanent magnet (C-PM) and magnetic elasticity for the design and control of a magnetic series elastic actuator (Mag-SEA). Unlike a conventional SEA typically designed by integrating an elastic element into an actuator through a mechanical leadscrew (Mech-LS), there is no physical contact between the rotor and translator of a Mag-SEA where their “gap” plays the role of a noncontact “magnetic spring” as the rotor magnetically drives the translator like a LS through helical PMs. Using a distributed current source method verified with analytical solutions and finite element analyses, the magnetic force vector of a Mag-SEA built with C-PM is derived and evaluated by comparing it with that designed with cylindrical PMs to approximate the helical PMs. With the magnetic elasticity computed using the DCS method and a control-oriented perturbation model, the parametric effects on the dynamics and stability are investigated numerically to gain insights into the plant characteristics of a Mag-SEA.