Rotational angle detection apparatus and rotational angle detection method

A rotational angle detection method for detecting a rotational angle of a magnetic field generation source based on magnetic fields detected by a magnetic field detection apparatus that detects magnetic fields in at least two directions, comprising:

• calculating correction values for correcting an angle error of the rotational angle, based on a steady-state error that does not depend on rotation of the magnetic field generation source;
• and
• calculating the rotational angle of the magnetic field generation source based on detection data of the magnetic field detection apparatus and the correction values, and outputting an angle signal indicating the rotational angle.

A rotational angle detection apparatus comprising:

• a data acquiring section that acquires detection data in a magnetic field detection apparatus, in at least two angle states between which a rotational angle of the magnetic field generation source differs;
• and
• a correction value calculating section that calculates correction values for correcting an angle error of the rotational angle corresponding to a difference between a first coordinate system in which the magnetic field generation source rotates and a second coordinate system of the magnetic field detection apparatus, based on the detection data in the at least two angle states and a steady-state error of the rotational angle corresponding to the difference between the first coordinate system and the second coordinate system.