US Patent 8959681 Ground sensor control of foot section retraction

A method and apparatus for controlling movement of members of a patient support apparatus by detecting obstructions to movement of members of the frame of the patient support apparatus and controlling the drives that move the members to prevent contact with the obstruction while achieving a desired position as quickly as possible. Proximity sensors positioned on member of the patient support apparatus at potential contact points prevents members of the patient support apparatus from contacting other members or obstructions such a floor, for example.