An Automated Storage and Retrieval System

An automated storage and retrieval system comprising:

• a) a plurality of vertically stacked storage levels, the plurality of vertically stacked storage levels including a storage area distributed over the plurality of vertically stacked storage levels, the plurality of vertically stacked storage levels including at least one in-bound area for entering the storage area and at least one out-bound area for exiting the storage area;
• b) a plurality of carriages on which one or more items are placed and which dare configured to be removable and parked in the storage area;
• c) a plurality of autonomous transport vehicles, each autonomous transport vehicle of the plurality of autonomous transport vehicles being configured to move any one of the plurality of carriages in the storage area;
• d) a multi-level vertical loop conveyor, the multi-level vertical loop conveyor including:
• i) a drive member;
• ii) a plurality of platforms coupled to the drive member, the plurality of platforms being spaced apart corresponding to a spacing between the plurality of vertically stacked storage levels, each of the plurality of platforms having a support surface being configured to support at least one of the plurality of carriages;
• iii) a guide member for guiding movement of the plurality of platforms around a continuous vertical loop;
• and
• iv) a drive mechanism coupled to said drive member and being configured to move the plurality of platforms vertically one behind another around the continuous vertical loop;
• e) a navigation system for guiding the plurality of autonomous transport vehicles in the storage area;
• and
• f) a control system operatively coupled to the drive mechanism and communicatively coupled to the navigation system, the control system being configured to control movement of the drive member so that at least one of the plurality of platforms will be at a level corresponding to at least one of the plurality of vertically stacked storage levels in response to one or more signals from the navigation system indicating that at least one of the plurality of autonomous transport vehicles is positioned in the at least one in-bound or the at least one out-bound area.