The Research About The Synchronous Control For The Traction And Rolling Of The Plastic Film

The quality of the plastic film rolling determines the last value of the use. The research about the synchronous control for the traction and rolling of the plastic film aims at keeping the line speed and the tension invariable and preventing the plastic film from extension and less tension.The load of the traction motor belongs to constant torque loads. The load of the rolling motor belongs to constant power loads. The rules of the timing of the traction motor and the rolling motor during rolling and reversal are analyzed respectively. The scheme of the synchronous control of constant line speed and constant tension during the traction and rolling of the plastic film is accomplished. The variable frequency regulating speed technique on the flux vector control is chose. The electric designs of the main loop and the control loop for the concrete example are accomplished. The software of the control loop is designed.The traction motor adopts the timing with the quality of constant torque. The rolling motor adopts the timing with the quality of constantpower. The initializations of the rotate speeds of the traction motor and therolling motor are worked out by the initialization of the line speed. The pulse with high frequency from the photoelectric coders enters into the ports for high-speed counters of PLC. The SPD instruction of PLC works out the rotate speeds of the traction motor and the rolling motor. The diameter of the film coil is worked out by real-time calculation. The rotate speed of the traction motor multiplied by .the driving proportion of the two motors compares with the rotate speed of the rolling motor. The difference serves as the expiatory and feedback value of the initialization of the rotate speed of the rolling motor. The initialization and the expiatory and feedback value enter into the inverter with the function of inputting analog signals and the built-in PI adjuster. The loop control of the rotate speeds is achieved accordingly. The PI control of the tension is carried out by the PID functional instruction of FX2N-The personal computer as upper machine connects to PLC as lower machine by the SC-10 cable. The special software FX-PCS/WIN-C makes the near communication and the remote communication between the personal computer and the PLC easy.