Track arrangement, an automated storage and retrieval system and an automated storage and retrieval method

A track arrangement for self-driven carriages in a storage rack arrangement for automatically storing and accessing objects, the storage rack arrangement comprises a plurality of storage sites arranged in at least one rack extending over k storage levels, wherein the track arrangement connects each storage level with at least one interaction site for automatically processing stored objects and/or automatically issuing objects to be stored, the track arrangement comprising:

• a plurality of interaction sites;
• at least Z track levels, wherein Z≥k,
• an entry point on the mth track level for one of the interaction sites, wherein m∈{1, . . . , Z}, and
• an exit point on the nth track level for one of the one of the interaction sites, wherein n∈{1, . . . , Z}, wherein the track arrangement further comprises for each interaction site:
• Z−m first one-way ramps directed downward towards the entry point,
• m−1 second one-way ramps directed upward towards the entry point,
• Z−n third one-way ramps directed upward away from the exit point, and
• n−1 fourth one-way ramps directed downward away from the exit point, wherein one first sequence of first ramps, one second sequence of second ramps, one third sequence of third ramps and one fourth sequence of fourth ramps is unambiguously associated with exactly one interaction site.