Patent ID: 6845834

Claim:
A movable rack system comprising a plurality of movable racks that travel freely back and forth along a travel path while being supported by a plurality of travel support devices, wherein out of the plurality of travel support devices, two travel support devices are positioned in opposite outside portions in a traverse direction to the travel path, each of the travel support devices including a rotation drive means, each of the travel support devices being a driven travel support device; and each of the movable racks includes travel amount detection means respectively detecting travel amounts of the driven travel support devices positioned in the opposite outside portions, and a control means for controlling drive rotation amounts of the rotation drive means, based on detection results by the travel amount detection means; the control means performing a movable rack attitude correcting control by finding predicted values for the travel amounts of the driven travel support devices respectively detected by the travel amount detection means, based on a time period elapsed immediately after the movable rack started traveling until the deviation between the travel amounts of the two driven travel support devices exceeds a prescribed travel amount, and on subsequent travel amounts of the driven travel support devices, when the deviation in the travel amounts of the driven travel support devices exceeds the prescribed travel amount, so that the drive rotation amounts of the rotation drive means are correctively controlled to eliminate the deviation between the predicted values.