The invention relates to a vehicle chassis (6) for checking and/or counting stock (4) in a warehouse (3) and configured for attaching to an autonomous indoor vehicle (9), with an extendable mast (11) comprising a first end (12) mounted onto the chassis (6) and an opposite second end (13) arrangeable at different distances above the chassis (6), and at least one scanner (2) arranged at the second end (13) and configured for checking and/or counting stock (4) in a shelve (5) of the warehouse (3) lateral to the vehicle (1). The invention further relates to an autonomous robot vehicle (1) comprising the vehicle chassis (6) and the autonomous indoor vehicle (9), whereby the chassis (6) is mounted onto the autonomous indoor vehicle (9) such that the autonomous indoor vehicle (9) and the chassis (6) are configured for autonomously moving the vehicle (1) in the warehouse (3).