Design and dual-loop control of a wearable electric force-feedback device for virtual training

Abstract. Virtual training is increasingly used in equipment maintenance. However, conventional haptic devices often suffer from limited force accuracy and poor wearing comfort in limb-interaction scenarios. This study presents an electro-actuated wearable force-feedback device for forearm interaction based on a compact direct current (DC) servo motor and cam mechanism. A simplified mathematical model is established to relate cam rotation angle to output feedback force, enabling quantitative force control. To handle dynamic load variations, a phase-shift–torque dual closed-loop control strategy is implemented by coordinating position and current regulation. The system is validated through physical experiments and virtual maintenance training, demonstrating rapid collision response and stable performance. Experimental results show a maximum feedback force of 32.37 N and consistently low errors. Overall relative errors were maintained within approximately 4.6 % and there was minimal variance across repeated trials. These results indicate that the proposed device can reliably enhance realism and immersion in virtual training applications.