The Harness

The wearer of the backpack, when the backpack has its movement rail setup, would need to wear a harness that allows the backpack to latch on/off the user's back.

As there will be a lot of forces at the latching location, the harness likely needs to consist of a rigid formed plate that touches a few points on the back of the wearer. These points should be large and padded enough not to cause hard or too much uneven pressure. As well as alow thw wearer to still bend their back and move their arms.

Adjustable straps along with back plate and mounting latch/interface used by the backpack.

May contain its own electronics that connect to the can bus through the latch.

Latching system

Ideas

Uses the rotational capabilities of the mounting point for locking the latch as well as alignment.