Modeling of a Linear Variable Structured Elastic Actuator Considering Modal Transition of Electromagnetic Clutch

Abstract

In the industrial society, high-speed motion is required for improving production efficiencies. We proposed the model of a linear variable structured elastic actuator (LVSEA) considering modal transition of the electromagnetic clutch. A load side of the LVSEA realizes high-speed linear motion compared to a conventional ball screw system driven by the geared motor. However, the load of the LVSEA may attack a lock mechanism because springs are not connected to the load and a motor housing. Therefore, the clutch should be reconnected at the desired time to prevent the load from attacking the lock mechanism. In our previous study, the dynamics of the LVSEA were separated into two parts according to the clutch state because we regard the clutch as a switching mechanism. However, in actuality, the slipping phenomenon occurs in a rotor and an armature of the electromagnetic clutch, and it causes the modeling error of the LVSEA. We proposed four dynamics of the LVSEA considering the clutch slipping. The proposed model and the experimental results were compared, and the accuracy of the model was verified. The root mean square error (RMSE) of the proposed model linear velocity was about 6.05 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−3</sup> m/s. Therefore, the accuracy of the proposed method was verified in the experiment.