Patent ID: 8027771

Claim:
Method to monitor a sensing system configured to monitor rotational speed of an output shaft of an electro-mechanical transmission, comprising: monitoring rotational speed of a wheel operatively connected to a driveline operatively connected to the output shaft of the electro-mechanical transmission; determining a first expected rotational speed of the output shaft of the transmission based upon the rotational speed of the wheel; determining rotational speeds of first and second electric machines operatively connected to the transmission; calculating a second expected rotational speed of the output shaft of the transmission based upon the rotational speeds of first and second electric machines when the electro-mechanical transmission is operating in a continuously variable operating mode; comparing the first and second expected rotational speeds of the output shaft and a signal output from the sensing system configured to monitor rotational speed of the output shaft of the electro-mechanical transmission; and wherein comparing the first and second expected rotational speeds of the output shaft and the signal output from the sensing system configured to monitor the rotational speed of the output shaft of the electro-mechanical transmission further comprises: averaging the first and second expected rotational speeds of the output shaft of the transmission; and comparing the signal output from the sensing system to the average of the first and second expected rotational speeds of the output shaft of the transmission.