Method and apparatus for computing an angle of rotation

1. A method for computing the angle of rotation of a rotational-angle sensor apparatus with a first Hall measuring plate and a second Hall measuring plate, comprising the steps of:

measuring first Hall voltage values (V HX (t=0), V HX (t=1)) at the first Hall measuring plate at a first time and a second time;

measuring second Hall voltage values (V HZ (t=0), V HZ (t=1)) at the second Hall measuring plate at the first time (t=0) and the second time (t=1);

computing the first nominal average value (V HX (t=0.5)) of the first voltage value and of the second nominal average value (V HY (t=0.5)) of the second Hall voltage value;

computing the first nominal angular value α(t=0) from the arctangent function of the first Hall voltage value V HX (t=0) and the second Hall voltage value V HZ (t=0) at a time t=0;

computing the second nominal angular value α(t=1) from the arctangent function of the first Hall voltage value V HX (t=1) and the second Hall voltage value V HZ (t=1) at a time t=1;

computing the nominal angle difference (Δα) from the difference between the second nominal angular value (α(t=1)) and the first nominal angular value (α(t=0));

computing the derivative of the first Hall voltage value by the difference Δ HX between the measured first Hall voltage value (V HX (t=0), V HX (t=1)) at a first time (t=0) and the second time (t=1) and the nominal angle difference;

computing the derivative of the second Hall voltage value by the difference Δ HZ between the measured second Hall voltage value (V HZ (t=0), V HZ (t=1)) at a first time (t=0) and the second time (t=1) and the nominal angle difference (Δα);

computing the angular value α by the following equation:

α

=

tan

-

1

⁡

(

V

HZ

⁡

(

t

=

0.5

)

-

Δ

⁢

⁢

V

HX

Δα

V

HX

⁡

(

t

=

0.5

)

+

Δ

⁢

⁢

V

HZ

Δα

)

.

2. A rotational-angle sensor arrangement, including:

a first Hall measuring plate for measuring a first Hall voltage;

a second Hall measuring plate for measuring a second Hall voltage arranged substantially orthogonally to the first Hall measuring plate; and

an evaluation unit for carrying out the method according to claim 1 .

3. The method according to claim 1 , wherein the angle of rotation is measured to enable at least one of an electronic commutation of synchronous motors, an automatic transmission, measurement of a position of a steering wheel, a position of a gearshift lever, a pedal position for an accelerator or a clutch or for ascertaining the height of the chassis.