Friction plausibility detection for a steering system

摘要

An apparatus and method for detecting and identifying friction in a vehicle having an electric power steering system comprising the steps of measuring predetermined vehicle states, estimating vehicle states using predetermined signals to define idealized vehicle states, calculating a confidence factor to be applied to the idealized vehicle states to determine valid idealized vehicle states, comparing the measured predetermined vehicle states to the valid idealized vehicle states to isolate signal data of interest and define an estimate of friction present in the steering system, applying friction boundaries to the estimate of friction present in the steering system, qualifying the estimate of friction, and acknowledging the presence of high friction in the event the estimate of friction exceeds the friction threshold boundaries for a predetermined time.