With follow-up control, the sensor and tool are mounted jointly on a linear guide. Here, the sensor detects the position of the web and thus determines the actual position value of the tool. This is compared with the target value and is output to the actuator as a correction signal. Through position control or follow-up control, the tool is always followed up with a constant distance to the guide reference.
Area of use
Follow-up controllers are used when processes such as coating or cutting must be executed with a constant distance to the web edge or a guide reference on the web.
The highest accuracy in position control is reached when the sensor and tool (doctor blade limitation) can be assembled in compact form on a linear unit. Edge detection takes place always in front of the tool, in the direction of web travel.