A device for detecting a failed resolver

摘要

In the field of automated guided vehicles it is particularly important that speed and steering angle feedbacks be accurate and reliable. Any deviations in these feedback signals should be promptly detected and used to alter operation of the vehicle. An apparatus (10) constantly monitors the time varying output signals of a pair of resolvers (66, 184) respectively associated with wheel rotation and steering angle. The loss of either of the resolver signals for more than a preselected duration of time related to the excitation frequency and vehicle speed results in the power delivered to an electric drive motor (220) being discontinued and the vehicle brakes being applied.