Based on vehicle kingpin Angle measuring theory, the paper analyzes the measuring errors of kingpin inclination Angle and kingpin caster Angle from wheel steering Angle measuring errors.
The model showed that the factors affecting the caster measuring precision are the kingpin inclination, the camber, and the turntable Angle.
On the base of balance equations of tire aligning torque and aligning resisting torque, the formula for calculating kingpin inclination of front wheel is derived and verified by calculation and testing on a production light vehicle.
