Abstract:
A method (100) for detecting a loss of motor control in an electric power steering system is disclosed. In an exemplary embodiment, the method (100) includes determining a duty cycle of a steering command signal (104) generated by a controller. The steering command signal (104) commands a steering mechanism to be turned in either a first or a second direction, the second direction being opposite to the first direction. A steering velocity (106) of the steering mechanism is determined, the steering velocity (106) being characterized by a steering velocity magnitude and a steering velocity direction whenever the steering velocity is greater than zero. The steering velocity direction corresponds to either the first or the second direction. The duty cycle is then compared to a first selected value (108), and the steering velocity magnitude is compared to a second selected value (112). If the duty cycle exceeds the first selected value (108), the steering velocity magnitude exceeds the second selected value (112), and the steering velocity direction is opposite to the direction commanded by the steering command signal (114), then a fault signal is generated (116).