α	Angle between normal vectors of Plane A and B
β	Angle between centerline and normal vector of Plane A
θ	Toe angle (deg.)
d_t	Horizontal distance between laser source and the mark from the other laser source (m)
L	Wheel track width (m)
φ	Toe angle (deg.)
d_c	Vertical distance between laser source and the mark from the other laser source (m)
γ	Angle between circle center and laser module (deg.)
r	Diameter of circle drawn by laser mark (m)
l	Distance from laser module and board (m)