Patent ID: 8539810
Filing Date: 2013-09-24
Classification: G01L,Y10T

Abstract:
1. A method for calibrating a torque measurement for a rotatable object, the method comprising: coupling the rotatable object to a structure, the structure comprising a first member and a second member, each extending along a length of a surface of the rotatable object and disposed on opposite sides of the rotatable object; coupling the rotatable object to an adapter; applying a known torque to the rotatable object via the adapter with the rotatable object in a stationary condition; measuring a first rotational displacement of the rotatable object via a first pair of sensors coupled to the first member and the second member at a first axial location of the rotatable object and circumferentially spaced from each other at an angle of about 180 degrees; measuring a second rotational displacement of the rotatable object via a second pair of sensors coupled to the first member and the second member at a second axial location of the rotatable object, and circumferentially spaced from each other at an angle of about 180 degrees, thereby accounting for bending of the rotatable object; and determining first and second angular displacements of the rotatable object based on the first and second rotational displacements.