Multi-channel signal transmission method of non-contact slip ring based on capacitive coupling and quasi-time division multiplexing

The single-axis rotary inertial navigation system can use the rotary joint to compensate the drift error of the inertial components. Therefore, whether the signal can be transmitted in the rotary joint freely, accurately, for a long time, and without maintenance determines the accuracy of inertial navigation. A noncontact slip ring based on capacitive coupling and quasitime division multiplexing is proposed in this paper. First, the theoretical calculation is carried out on the method of signal transmission using two pairs of capacitors, and the factors affecting signal quality are analyzed. Second, the principle of quasitime division multiplexing and Manchester encoding is used to solve the problems such as converting multiple signals into a single signal, capacitor cannot transmit DC signal, and signal synchronization. Finally, an improved differential transmission method is designed to enhance the anti-interference of the system and to solve the level mismatch of the primary and secondary circuits. In this paper, a prototype is designed to verify the method. When the transmission rate of the three navigation signals is 1 Mbps, the navigation signals can be transmitted without distortion. And the maximum transmission frequency is 17 MHz, which can be further improved. The experimental results show that the proposed method provides a new design for the signal transmission of noncontact power slip ring. It has the advantages of high reliability, fast transmission rate, and good versatility. It can be applied to aviation, aerospace, navigation, wind power generation, and other fields where the power and signal need to be transmitted simultaneously.