Patent ID: 6862551

Claim:
A method for measuring an absolute steering angle of a steering shaft for a vehicle using a first rotatable body and a second rotatable body that rotate together with the steering shaft of the vehicle at a predetermined rotation ratio, respectively, the method comprising: organizing a table by matching a plurality of relative rotational angle pairs (Ψ′, θ′), wherein Ψ′ is a relative rotational angle of the first rotatable body, and θ′ is a relative rotational angle of the second rotatable body, with respective absolute steering angles, Φs, corresponding to each of the relative rotational angle pairs; obtaining a Ψ M ′ value by measuring the relative rotational angle Ψ′ of the first rotatable body and obtaining a θ M ′ value by measuring the relative rotational angle θ′ of the second rotatable body using angle sensors having measurement ranges of Ω; and obtaining an absolute steering angle Φ of the steering shaft corresponding to the measured relative rotational angle pair (Ψ M ′, θ M ′) by looking up the table.