发明名称 |
Precise control of the rotational velocity of brushless alternating current electric servo motors |
摘要 |
A brushless AC servo motor control and modified motor to minimize the rotational acceleration and deceleration of a semiconductor wafer during processing steps where fluid is applied in a thin coating on the wafer. The control utilizes sine and cosine encoder outputs of single cycle and multiple cycle per revolution to calculate motor shaft position by an inverse tangent calculation of sine and cosine ratios. Resolution of motor shaft position is greatly improved as is rotational velocity control. In response to a prediction of desired shaft position in comparison with actual position the three field currents are adjusted to change the torque applied to the rotor and shaft. In the semiconductor wafer manufacturing application the motor shaft is modified to permit vacuum attachment of the wafer to the disc that rotates with the shaft.
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申请公布号 |
US5932986(A) |
申请公布日期 |
1999.08.03 |
申请号 |
US19970811681 |
申请日期 |
1997.03.05 |
申请人 |
WHEDCO, INC. |
发明人 |
HENRY, WILLIAM B.;FIREHAMMER, PAUL |
分类号 |
G05B19/29;H02P1/00;(IPC1-7):G05B19/29 |
主分类号 |
G05B19/29 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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