Vehicle steering angle position determination method

A method of estimating the true steering angle value of a vehicle, said method comprising:

• obtaining a relative position steering angle value;
• obtaining at least one vehicle operating parameter value;
• calculating at least one estimated value, said estimated value being a function of a vehicle model including at least one variable corresponding to said at least one vehicle operating parameter value;
• estimating a steering angle offset value as a function of said estimated value;
• estimating the true steering angle value of the vehicle as a function of said relative position steering angle value and said steering angle offset value;
• and wherein prior to estimating the actual steering angle value said method includes:
• selecting data acceptable for use in estimating said steering angle offset value, wherein data acceptable for use includes data obtained when the sign of a sensor-measured yaw rate of the vehicle (vGimeas) is the same as a model-based yaw rate (vGiVr) calculated using front and rear axle operating parameters;
• and data obtained when the sign of vGimeas is opposite the sign of vGiVr when relatively straight rearward driving is detected.

A method of estimating the true steering angle value of a vehicle, said method comprising:

• (a) obtaining a relative position steering angle value;
• (b) obtaining at least one vehicle operating parameter value;
• (c) calculating at least one estimated value, said estimated value being a function of a vehicle model including at least one variable corresponding to said at least one vehicle operating parameter value;
• (d) estimating a steering angle offset value as a function of said estimated value;
• (e) estimating the true steering angle value of the vehicle as a function of said relative position steering angle value and said steering angle offset value;
• (f) repeating steps (a) through (e) and assigning a Percent Certainty value to each estimated true steering angle value, said Percent Certainty value being a function of the number of repetitions of steps (a) through (e);
• and
• (g) communicating said estimated true steering angle value and said Percent Certainty value to a controller.