Multi-motor synchronization variable speed drive of dyeing and printing machines without dancers and tension sensor;

The paper studied the principle of the all-angle MUM(Mass-Unbalanced Modulation) reading realized through synchronous demodulation,discussed the factors that influenced the reading precision,and analyzed the reading errors resulted from the non-orthogonality of the electrodes-fixed frame and the inconsistent between the scale factors of different measuring channels.

MFSK signal can be demodulated by synchronous demodulation and envelope demodulation.

In synchronous demodulation, frequency and phase of a local carrier must be synchronous with sending station, distortion will be caused in output signals of demodulation as frequency error and phase error occur in the local carrier.

The design scheme is tested and debugged on a three-phase asynchronous motor in the end,and the results show that the method of mixed modulation has lower current harmonic,more efficient use of supply voltage,lower noise than the synchronized modulation and asynchronized modulation.

This paper briefly analyzes some kinds of general synchronous adjustment methods, and puts forward a kind of synchronous adjustment method based on sampling sequence number, and carries out the precision analysis for the method.

The development of new rolling mill usesthe advantages of early non-synchronous adjustment multi-head spiral rolling mill and overcomes its shortcomings.