Storage and retrieval system transport vehicle

An autonomously guided autonomous transport vehicle comprising:

• a frame forming a payload section configured to hold one or more pickfaces;
• a mast mounted to the frame to move relative to the frame along a traverse axis;
• a transfer arm dependent from the mast and configured to support thereon the one or more pickfaces;
• a drive section connected to the frame having at least one drive axis operably coupled to the transfer arm, so as to actuate the transfer arm on the fly along a lift axis lifting the one or more pickfaces on the transfer arm along the mast on the fly with transport by the autonomous transport vehicle;
• and
• a controller connected to the drive section, the controller being configured to effect on the fly positioning relative to the frame of the transfer arm along the lift axis so as to effect on the fly position relative to the frame of the one or more pickfaces carried by the autonomous transport vehicle.

A method of transporting pickfaces with an autonomously guided autonomous transport vehicle, the method comprising:

• providing a frame of the autonomously guided autonomous transport vehicle, the frame forming a payload section configured to hold one or more pickfaces;
• providing a mast mounted to the frame to move relative to the frame along a traverse axis;
• providing a transfer arm dependent from the mast and configured to support thereon the one or more pickfaces;
• providing a drive section connected to the frame having at least one drive axis operably coupled to the transfer arm, so as to actuate the transfer arm on the fly along a lift axis lifting the one or more pickfaces on the transfer arm along the mast on the fly with transport by the autonomous transport vehicle;
• and
• effecting, with a controller connected to the drive section, on the fly positioning relative to the frame of the transfer arm along the lift axis so as to effect on the fly position relative to the frame of the one or more pickfaces carried by the autonomous transport vehicle.