Patent ID: 6417643
Filing Date: 2002-07-09
Classification: B41F,B41P,H02P

Abstract:
A synchronous control device including a master section and a slave section for controlling a rotational frequency and the rotational phase between a master electric motor and a slave electric motor, or between a shaft of a master machine and a shaft of a slave machine driven by the respective electric motors, comprising:a deceleration device with a deceleration rate of 1/N (N is a positive integer) for connecting said master electric motor and said shaft of the master machine; a deceleration device with a deceleration rate of 1/N (N is a positive integer) for connecting said slave electric motor and said shaft of the slave machine; a master rotary encoder for outputting pulses in response to said master electric motor; an origin detector of the shaft of the master machine for detecting one rotation of said shaft of the master machine; a slave rotary encoder for outputting pulses in response to said slave electric motor; an origin detector of the shaft of the slave machine for detecting one rotation of said shaft of the slave machine; in the slave section, further comprising: a rotational frequency detector for constantly detecting a rotational frequency of said master electric motor by a signal outputted from said master rotary encoder; a rotational frequency feedback detector for constantly detecting a feed back rotational frequency of said slave electric motor according to the signal outputted from said slave rotary encoder; a phase detector of the master electric motor for constantly detecting rotational phase of said master electric motor according to the output of said master rotary encoder and being cleared every one rotation of said master rotary encoder; a phase detector of the slave electric motor for constantly detecting rotational phase of said slave electric motor according to the output of said slave rotary encoder and being cleared every one rotation of said slave rotary encoder; a phase detector of the shaft of the master machine for constantly detecting a rotational phase of said shaft of the master machine according to the output of said master rotary encoder and being cleared by the output of said origin detector of the shaft of the master machine; a phase detector of the shaft of the slave machine for constantly detecting a rotational phase of said shaft of the slave machine according to the output of said slave rotary encoder and being cleared by the output of said origin detector of the shaft of the slave machine; a first phase deviation detector for calculating the output of said phase detector of the shaft of the master machine and the output of said phase detector of the shaft of the slave machine so as to output a phase deviation between said shaft of the master machine and said shaft of the slave machine; and a second phase deviation detector for calculating the output of said phase detector of the master electric motor and the output of said phase detector of the slave electric motor so as to output a phase deviation between the said master electric motor and said slave electric motor; wherein a first origin matching between said shaft of the master machine and said shaft of the slave machine based on the output of said first phase deviation detector, said rotational frequency detector and said rotational frequency feedback detector is completed, then, when a phase deviation between said shaft of the master machine and said shaft of the slave machine is within the predetermined phase deviation, a second origin matching between said master electric motor and said slave electric motor based on the output of said second phase deviation detector, said rotational frequency detector and said rotational frequency feedback detector continuously is completed so as to perform a synchronous control between said master section and said slave section.