Patent ID: 8198851
Filing Date: 2012-06-12
Classification: B41J,G05B,H02P

Abstract:
1. A motor controller for driving an electric motor comprising: a control unit configured to receive a detection signal from an operation-amount detector and configured to generate a driving force for driving the electric motor in response to a command signal, the operation-amount detector being configured to detect an amount of operation of the electric motor or a machine, the control unit being configured to provide a feedback loop for controlling the electric motor such that the amount of operation matches the command signal; a disturbance signal generator configured to add a disturbance signal to the driving force generated by the control unit; a compensation-driving-force detector configured to detect the driving force generated by the control unit; a vibration calculator configured to calculate a magnitude of vibration and a vibration frequency, the magnitude of vibration being calculated on the basis of an absolute value or a square value of a signal detected by the compensation-driving-force detector or the operation-amount detector; and an oscillation detector configured to detect an oscillation of the feedback loop by evaluating the signal detected by the compensation-driving-force detector or the operation-amount detector on the basis of at least one first predetermined threshold based on a magnitude of the signal detected by the compensation-driving-force detector or the operation-amount detector and at least one second predetermined threshold based on the vibration frequency.