Article transport facility

An article transport facility comprising:

• a pair of travel rails extending along a travel route;
• a transport vehicle configured to travel along the travel route and transport an article;
• a guide rail configured to guide a direction of travel of the transport vehicle in a branch-junction section in which the travel route branches and joins another route;
• and
• a control system configured to control the transport vehicle,
• wherein the transport vehicle comprises:
• travel wheels configured to roll on upper surfaces of the pair of travel rails;
• a guide wheel configured to roll on a first-side surface or a second-side surface of the guide rail, the first-side surface facing a first side Y1 and the second-side surface facing an opposite second side Y2 in a width direction Y orthogonal to a travel direction X extending along the travel route;
• and
• a guide wheel drive unit configured to move the guide wheel in the width direction Y between a first position at which the guide wheel rolls on the first-side surface and a second position at which the guide wheel rolls on the second-side surface,
• wherein the branch-junction section comprises:
• a first section;
• a second section extending side by side with the first section;
• and
• a connecting section connecting the first section and the second section,
• wherein the connecting section branches off from the first section toward the first side Y1 in the width direction Y and joins the second section from the second side Y2 in the width direction Y,
• wherein the guide rail comprises:
• a branch guide portion spanning from the first section to an intermediate position in the connecting section;
• a junction guide portion spanning from an intermediate position in the connecting section to the second section;
• and
• a switching area, located along the travel direction X, configured to allow the guide wheel to move, in the width direction Y, between the branch guide portion and the junction guide portion,
• wherein in a case where the transport vehicle travels through the branch-junction section:
• the control system is configured to execute preliminary biasing processing including controlling the guide wheel drive unit to bias the guide wheel in a direction from the first position toward the second position while the guide wheel is at the first position and is in contact with the first-side surface of the branch guide portion from the first side Y1 in the width direction Y prior to entering the switching area, and
• the control system is further configured to cause the guide wheel to move in the switching area by executing the preliminary biasing processing to keep the guide wheel in contact with the first-side surface from the branch guide portion to the switching area.