Patent ID: 9440632
Filing Date: 2016-09-13
CPC Classification: B60T

Claim Text:
1. A method of monitoring brake operation on a vehicle comprising: receiving a brake demand signal indicative of a brake demand; receiving at least one stability signal of the vehicle; receiving a plurality of wheel speed signals from individual wheel speed sensors associated with individual wheel ends of the vehicle; determining a master value based on the plurality of wheel speed signals over an initiation time period for comparison with the plurality of wheel speed signals; determining the velocity of the vehicle is equal to or greater than a predetermined minimum velocity; determining the vehicle is not being controlled by an active safety system; determining the brake demand signal is greater than a predetermined minimum braking threshold and less than a predetermined maximum braking threshold; selecting a wheel speed signal having the lowest velocity of the plurality of wheel speed signals when the brake demand is no longer present; calculating the difference in the selected wheel speed signal from the master value, wherein a predetermined short-term time period has not elapsed; calculating an integrated difference; incrementing an error counter by one increment when the integrated difference is greater than a short-term threshold to arrive at an accumulated brake drag count; determining a brake drag fault exists at the wheel end associated with the selected wheel speed signal when the accumulated brake drag count is greater than an error count threshold and the predetermined short-term time period has not elapsed; and transmitting a brake control signal at the output to the at least one brake control device to reduce the pressure at the wheel end associated with the brake drag fault.