Patent ID: 8001848
Filing Date: 2011-08-23
Classification: F16H,G01L

Abstract:
1. A method for measuring torque using a torque measurement apparatus, wherein the method comprises the steps of: providing a rotatable shaft having a longitudinal axis, a first end and a second end, said first end connected to said power supply, said second end connected to said load; providing a first detectable feature associated with a first longitudinal position of said shaft; providing a second detectable feature associated with a second longitudinal position of said shaft; providing a plurality of sensors including a first sensor and a second sensor, said first sensor proximate to said first detectable feature, said second sensor proximate to said second detectable feature; producing a first signal, via said first sensor, as said rotatable shaft rotates about said longitudinal axis; producing a second signal, via said second sensor, as said rotatable shaft rotates about said longitudinal axis; sampling said first and second signals, via said controller, such that said first and second signals are aliased; utilizing said controller to calculate a first Fourier coefficient for said first signal and a second Fourier coefficient for said second signal using one of an inner product method and a discrete Fourier transform method; calculating a relative phase, via said controller, between said first and second signals using said first and second Fourier coefficients; and utilizing said controller for calculating said shaft torque using said relative phase.