Optimal servo system and modulation method of mechanical antenna array

As a new communication pattern, the Rotating Magnet-Based Mechanical Antenna (RMBMA) can significantly reduce both the size and the power consumption of the super-low frequency electromagnetic transmitter. However, it has the problems of weak radiated magnetic field intensity and low communication baud, limiting its practical applications. To solve these problems, this paper proposes a RMBMA array system based on the direct drive of permanent magnet synchronous motor. For the working conditions of high transient current and frequent speed switching of mechanical antenna signal modulation, a position difference coordinated-control strategy based on the deadbeat current prediction model is proposed, which improves the servo performance of the system and meets the application requirements. The proposed position difference coordinated-control parameters are designed, and the servo performance, stability and robustness of the system are theoretically verified. The high transmission rate and low bit error rate of the modulation signal of the mechanical antenna are realized. Finally, an experimental test platform for the mechanical antenna array system is built, and the distribution of the magnetic field strength in the near area and the servo performance of the drive system are tested experimentally. Compared with the single magnetic source, the magnetic field intensity in the near area of the system is doubled, showing that the problem of weak radiated magnetic field intensity can be effectively solved. The speed of the motor servo system has no overshoot and the adjustment time is ≤0.25 s, reaching the servo control index.