Research On Lorentz Motor And Drive For Ultra-Precision Vibration Isolation System

Lorentz force motor is a kind of permanent magnet DC actuator. It has the features ofsimple structure, fast dynamic response, linearity and has been widely used as a precisionlinear motion drive devices such as light micro-motion machine carved table drive motor,precision active damper actuators and so on. Lorentz motor drive directly affects theLorentz motor dynamic and static performance by controlling the motor current whichdecides the magnitude and direction of the Lorentz force. This paper designed a Lorentzmotor and driver used for active vibration control in ultra-precision active absorbers whichare always applied in the IC manufacturing equipments.Firstly, this paper illustrated the operating principle and characteristics of Lorentz motorand demonstrated some parameters such as motor thrust constant, inductance and resistance.On the basis of the parameters calculated, a set of Lorentz motor with a thrust constant of68N/A has been designed.Secondly, the details of the Lorentz motor drive hardware design, including the currentregulator circuit, bridge power conversion circuit, current feedback circuit, protectioncircuit and compensation circuit, have been demonstrated. Also, the drawing of the printedcircuit board and the mathematical model of the driver have been introduced. In the realresearch, the high-performance Lorentz motor driver has a bandwidth for at least3kHz.The current control precision can reach0.1mA and the current ripple is less than0.1mA.At last, a Lorentz motor test platform has been designed to test both the dynamicalperformance and the static performance of the motor. The test results show that the vibrationtransmissibility at the resonance point attenuated from15dB to-7dB when applied theLorentz motor active control.The Lorentz motor and drive has been successfully applied to ultra-precision activedamping absorbers, and has achieved good effect.