Microprocessor based dual converter control of on line tube cutting machine

The present work is concerned with the position control of the cutting mechanism carriage on a precision tube mill with the help of a DC shunt motor, fed by a dual hi-point power converter and controlled by microprocessor. The microprocessor is the heart of the control circuitry. This involves two feedback loops: one for checking speed and length travelled by cutting mechanism carriage and other for the measurement and setting of the required length. The latter loop counts the length being passed and at the near set length fires the converter appropriately to accelerate the cutting mechanism carriage. The motion of the cutting mechanism carriage is controlled by the former feedback loop, which also gives the cut signal, as soon as the speed of pipe and cutting mechanism carriage matches, and keeps this speed matched for the whole cutting period. After cutting, the carriage mechanism is brought back to the home position and waits for the next set length.