Method for measuring absolute steering angle of steering shaft for vehicle
First Claim
Patent Images
1. 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:
- obtaining a measured angle Ψ
M′
by measuring a relative rotational angle Ψ
′
of the first rotatable body with a first angle sensor whose measurement range is Ω
, and obtaining a measured angle θ
M′
by measuring a relative rotational angle θ
′
of the second rotatable body with a second angle sensor whose measurement range is Ω
;
calculating a plurality of relative rotational angles θ
′
s of the second rotational body that correspond to the Ψ
M′
, by using a functional relation between the relative rotational angle Ψ
′
of the first rotatable body and the relative rotational angle θ
′
of the second rotatable body, and obtaining calculation of angles θ
c′
s, the θ
c′
s being calculated by using a functional relation defined by the relative rotational angles of the first and second rotatable bodies;
obtaining a frequency i of the first rotatably body by comparing the plurality of θ
c′
s to the θ
M′
;
obtaining an absolute rotational angle Ψ
of the first rotatable body by using the i, and obtaining an absolute rotational angle Φ
1 of a steering shaft out of a relation between the Ψ and
an absolute rotational angle θ
of the second rotatable body; and
obtaining an absolute steering angle Φ
a of a steering shaft that corresponds to the Ψ
M′ and
the θ
M′
, by using a functional relation between Ψ and
θ
, a difference between the absolute rotational angle of the first rotatable body Ψ and
the absolute rotational angle of the second rotatably body θ
, and the absolute steering angle of the steering shaft Φ
a, andif a difference between the Φ
1 and the Φ
a is greater than a predetermined value, adding/subtracting to/from the Φ
1 a value that is obtained by dividing the Ω
by a rotation ratio of the first rotatably body.
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Abstract
A method for measuring an absolute steering angle of a steering shaft for a vehicle using two rotatable bodies that rotate together with the steering shaft of the vehicle at a predetermined rotation ratio.
10 Citations
4 Claims
-
1. 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:
-
obtaining a measured angle Ψ
M′
by measuring a relative rotational angle Ψ
′
of the first rotatable body with a first angle sensor whose measurement range is Ω
, and obtaining a measured angle θ
M′
by measuring a relative rotational angle θ
′
of the second rotatable body with a second angle sensor whose measurement range is Ω
;calculating a plurality of relative rotational angles θ
′
s of the second rotational body that correspond to the Ψ
M′
, by using a functional relation between the relative rotational angle Ψ
′
of the first rotatable body and the relative rotational angle θ
′
of the second rotatable body, and obtaining calculation of angles θ
c′
s, the θ
c′
s being calculated by using a functional relation defined by the relative rotational angles of the first and second rotatable bodies;obtaining a frequency i of the first rotatably body by comparing the plurality of θ
c′
s to the θ
M′
;obtaining an absolute rotational angle Ψ
of the first rotatable body by using the i, and obtaining an absolute rotational angle Φ
1 of a steering shaft out of a relation between the Ψ and
an absolute rotational angle θ
of the second rotatable body; andobtaining an absolute steering angle Φ
a of a steering shaft that corresponds to the Ψ
M′ and
the θ
M′
, by using a functional relation between Ψ and
θ
, a difference between the absolute rotational angle of the first rotatable body Ψ and
the absolute rotational angle of the second rotatably body θ
, and the absolute steering angle of the steering shaft Φ
a, andif a difference between the Φ
1 and the Φ
a is greater than a predetermined value, adding/subtracting to/from the Φ
1 a value that is obtained by dividing the Ω
by a rotation ratio of the first rotatably body. - View Dependent Claims (2, 3, 4)
-
Specification