| 摘要 |
Apparatus for controlling an elongate web 100, comprises first and second anchor means for retaining the first and second ends of the web respectively, and an actuator 109 adapted to displace the web transversely at a position intermediate the first and second ends. A controller for the actuator, includes a mathematical model of the strip, together with sensors to detect transverse position and/or velocity of the strip, the output thereof being provided as input to the mathematical model, and the controller being arranged to activate the actuator dependent on predictions made by the model. Ideally, proposed actuator inputs will be provided to the model as inputs and the actuation pattern selected which leads to damping of strip oscillations. In a hot dip galvanising line, the first and second anchor means are the tower and sink rolls respectively. It is preferred if the actuator is non-contact as this will cause the least damage to the zinc surface. Magnetic actuators are suitable. In a similar manner, non-contact position sensors are preferred, such as inductive sensors, laser range finders, and ultrasound. |
