Patent ID: 7316170

Claim:
A method for measuring backlash of an axial joint of an industrial robot having a first and a second robot knuckle being movably connected to each other in a direction of rotation of the axial joint, which comprises the steps of: providing a load-transmitting device for applying a predeterminable force or force function alternately directions along a measuring axis of the first robot knuckle, the load-transmitting device connected to a free end of a robot arm; using a deflection sensor for measuring a deflection of the first robot knuckle at a predeterminable distance from an axis of rotation of the axial joint resulting in measurement data; and using an evaluation device connected to the deflection sensor for calculating a rotational angle of the first robot knuckle as a measure of the backlash present at the axial joint, taking into account a measured deflection and a geometrical configuration of the disflection sensor and of the industrial robot.