Transport system

A transport system that transports a wagon that has a plurality of convex portions that protrude downward, the transport system comprising

• a mobile robot configured to move with the wagon mounted on the mobile robot, wherein
• the mobile robot comprises
• a platform that has a mounting surface on which the wagon is placed and that is configured to enter beneath the wagon,
• a raising and lowering mechanism configured to raise and lower the platform to change the height of the mounting surface to deliver the wagon,
• a plurality of concave portions in, and recessed below, the mounting surface corresponding to the plurality of convex portions of the wagon,
• an optical sensor on a side surface of at least one of the plurality of concave portions, and
• a controller configured to detect that at least one of the plurality of convex portions is inserted into the at least one concave portion according to a detection result of the optical sensor,
• the mobile robot is configured to mount the wagon by raising the platform to lift the wagon,
• the optical sensor includes a light projector configured to emit light toward the at least one concave portion and a light receiver configured to detect light reflected from the at least one of the plurality of convex portions,
• the light projector and the light receiver face laterally,
• the convex portion includes a cylindrical shaped portion and a hemispherical shaped portion, and
• the optical sensor is at a height aligned with the hemispherical shaped portion.