Study On Subdividing Drive And Measure-Amend Of Microstep For Step Motor

Step motor can be controlled to realize accurate positioning and rotation synchronization without feedback from displacement transducer or velocity transducer, which is in favor of miniaturization and lower cost of equipments. So step motor is widely used in many fields. With the progress of electronic and control technology, the application of new magnetism material, and the development of the theory and manufacture process of step motor, the application of step motor is promoted.The subdividing drive is a kind of driving technology that can effectively improve the step precision and characteristic of low frequency. It is mostly used when the equipments require high precision, low noise and low oscillation . Taking the VR step motor as example in the paper, systemic research is conducted about the principle of the subdividing drive ,the non-linearity relationship between microstep and phase current ,the method of velocity adjusting and the interrelated factors .The system is designed to realize the subdividing drive , velocity adjusting and position.Especially,there are two innovations in this paper.One is the first introduction of PLD device and ISP technology to the design of phase sequencer,the other is the new measure and amend method of microstep.With PLD device and ISP technology, the design and modify of the phase sequencer can easily be made by ABEL-HDL language.The capability of in-system-programable avoids the iterative pulling and plugging of EPROM.The new measure and amend method of micro step is specially used to measure and amend the microstep.In the base of the characteristic of the discrete current in phase , low resolution is used to substitute high resolution in the measure and amend process for reducing the cost of the process.Several mode of the subdividing drive are integrated in one system .So thecontrol become multiplex.The displacement can be divided to whole step part and microstep part. Microstep part is used to satisfy the precision of position, while whole step part is used to satisfy the speed of position.The pulse frequency and the ladder wave frequency are two factors that affect the range of velocity adjusting. The range of velocity adjusting is finally decided by the lesser.