Winding and unwinding system, control method, and preparation device for battery electrode sheet

A winding and unwinding system, comprising:

• at least two winding rollers;
• a roll-changing device, configured to drive the at least two winding rollers to sequentially move to a set position, wherein a winding roller located at the set position is able to wind a strip material;
• a sensing device, configured to emit an in-place signal when the winding roller located at the set position rotates one circle;
• a measuring device, configured to measure a traveling length of the strip material;
• and
• a controller, connected to the sensing device, the measuring device, and the roll-changing device, wherein the controller is configured to:
• in response to receiving the in-place signal, determine a winding radius of the winding roller located at the set position based on the traveling length measured by the measuring device;
• and
• send a roll-changing signal to the roll-changing device when the winding radius reaches a preset threshold;
• wherein the roll-changing device is further configured to, upon receiving the roll-changing signal, drive another winding roller to move to the set position and get in contact with the strip material, so that the strip material winds onto the another winding roller.