Patent ID: 8225657

Claim:
A method for quantitatively detecting an unbalanced state of a rotating shaft, comprising the steps of: driving the rotating shaft; acquiring a position signal, a velocity signal, an acceleration signal, and a torque signal of the rotating shaft; and establishing, according to a rotational kinetic energy and a potential energy of the rotating shaft, a Lagrange kinematics equation including an unbalanced amplitude variable and an unbalanced angle variable of the rotating shaft, and acquiring, according to the position signal, the velocity signal, the acceleration signal, and the torque signal, a value of the unbalanced amplitude and a value of the unbalanced angle of the rotating shaft by solving the equation by means of a nonlinear multivariable method; wherein the unbalanced amplitude of the rotating shaft is a product of a length of a vertical line segment from a centroid of the rotating shaft to an axis of the rotating shaft and a mass of the rotating shaft, and the unbalanced angle of the rotating shaft is an included angle between the vertical line segment from the centroid of the rotating shaft to the axis of the rotating shaft and a horizontal axial plane of the rotating shaft.