Patent ID: 7373721

Claim:
Method for measuring the relative rotation of a first object with respect to a second object comprising the steps of: arranging a flexible elongated element between said first and said second object and connecting ends of said flexible elongated element to said first and second objects, respectively, said element having a neutral axis, which does not change in length when bending, and defining at least one line spaced apart from said neutral axis and parallel to the neutral axis that extends from said first object to said second object, wherein said line is spaced apart from said neutral axis by a predetermined distance; rotating said first object relative to said second object; measuring a variation in length of said line during a relative rotation between said first and said second object, and calculating said relative rotation responsive to said length variation and said distance, said relative rotation being proportional to said length variation responsive to said distance independently of a shape of said line between said first and said second object.