H^∞ Control of Milling AMB Spindle

This study is concerned with the DSP-based H^∞ control of actual milling AMB spindle rotor systems. The H^∞ control systems are designed for five-axis control of one axial direction and four radial directions. We tried some simulations for comparison with conventional PID control. Next, we conducted the experiments using DSPs of TMS320C30 and TMS320C40 in cases of levitation and rotation. In experiments involving parameter variations of the rotor mass, which is called robust performance, it has been clarified that the H^∞ control system is superior to conventional PID control system. Safe, high-speed rotation was achieved up to 45000 rpm with little vibration. The control performance in high-speed rotations, in particular, the envelop of amplitudes at sensor locations depending on rotational speed is almost the same as that in PID control.