Patent ID: 7264078
Filing Date: 2007-09-04
Classification: B60K,B60W

Abstract:
1. In a vehicle having steerable front wheels, an interaxle differential for transmitting torque from an engine to the front wheels and to rear wheels, the differential having a controllable device operable to control a ratio of front wheel speed to rear wheel speed, a front wheel speed sensor, a rear wheel speed sensor, a steering angle sensor, and a control unit for controlling the controllable device as a function of sensed steering angles and stored information including steering angles and corresponding front to rear wheel speed ratio values, a method of automatically calibrating the control unit comprising: determining if the vehicle has been in a straight ahead steering mode for at least a certain time period; determining if a speed of the vehicle is greater than a threshold speed; replacing at least a portion of the stored information if the vehicle has been in said steering mode for at least said certain time period and if the speed of the vehicle is greater than said threshold speed; generating an average steering angle value derived by averaging an old steering angle value with a current steering angle value, if the vehicle has been in a straight ahead travel mode for at least a certain time period; and preventing replacement of the stored information if a magnitude of the average steering angle value is greater than a certain value.