Angle sensor and angle sensor system

An angle sensor for generating a detected angle value having a correspondence with an angle to be detected, comprising:

• a plurality of composite magnetic field information generation units for detecting, at a plurality of detection positions different from each other, a composite magnetic field which is a combination of a magnetic field to be detected and a noise magnetic field other than the magnetic field to be detected, the magnetic field to be detected being generated by a magnetic field generation unit located away from the plurality of detection positions, and thereby generating a plurality of pieces of composite magnetic field information including information on at least a direction, out of the direction and a strength, of the composite magnetic field, at each of the plurality of detection positions, the magnetic field to be detected varying in direction according to the angle to be detected, each of the plurality of pieces of composite magnetic field information including information on the direction of the composite magnetic field;
• and
• an angle computing unit configured to:
• define a function that minimizes a sum of squares of differences between respective corresponding ones of the plurality of pieces of composite magnetic field information and a plurality of pieces of assumed magnetic field information, and that calculates a first unknown and a second unknown, the first unknown being a value corresponding to the detected angle value, the second unknown being a value corresponding to the strength of the noise magnetic field, the plurality of pieces of assumed magnetic field information being information corresponding to the plurality of pieces of composite magnetic field information and assumed based on the first and second unknowns;
• estimate the first and second unknowns based on the plurality of pieces of composite magnetic field information and the function;
• determine the detected angle value based on the estimated first unknown;
• and
• generate the detected angle value.