Overhead transport vehicle and method for calculating rotation amount of winding drum in overhead transport vehicle

An overhead transport vehicle comprising:

• a lift stage to transfer an article;
• a winding drum to overlap and wind a suspension attached to the lift stage;
• and
• a controller to control a rotation amount of the winding drum to control a lifting/lowering amount of the lift stage;
• wherein
• the controller is configured or programmed to execute:
• a first processing including calculating, as individual values of the overhead transport vehicle, an individual value of an entire length of the suspension, an individual value of a diameter of the winding drum, and an individual value of a thickness of the suspension;
• and
• a second processing including calculating a rotation amount of the winding drum with respect to a lifting/lowering amount of the lift stage based on the individual value of the entire length of the suspension, the individual value of the diameter of the winding drum, and the individual value of the thickness of the suspension calculated in the first processing.