From the view of production technology, divide the control system of wire calender into three parts: tension control system, thickness control system and assistant control system, describe the function and automatic control principle of each part.

• 从生产工艺的角度,将钢丝压延机的控制系统分成张力控制系统、度控制系统、助系统等三大部分,论述各部分功能及自动控制原理。