A Wireless Servo Motor Drive with Bidirectional Motion Capability

In this paper, a novel wireless servo motor drive is proposed and implemented, which artfully integrates wireless power transfer into the dc servo motor drive to achieve wireless bidirectional servo motion. Prominently, there is no power converter or controller at the servo motor side to realize the bidirectional rotation, while the motor control is fully conducted at the transmitter side. The key is to adopt only one transmitter with LCL network to achieve power equalization of two receiver coils, hence realizing bidirectional motion. Meanwhile, the phase-shift control method is newly developed to perform the desired speed control at the transmitter side, without requiring any switched capacitor arrays. As a result, the proposed wireless bidirectional servo motor drive takes the definite advantages of electrocution free and totally sealable. Both calculation and experimental results are presented to validate the feasibility and controllability. For the prototype, the transmission distance can reach up to 130 mm and the transmission efficiency can be up to 85%.