Operation processing apparatus, torque sensor and power steering apparatus

An operation processing apparatus that computes torque generated in a first rotation shaft and a second rotation shaft connected via a torsion bar and arranged coaxially by using a first output signal including a first sine wave signal and a first cosine wave signal output from a first magnetic sensor element in accordance with rotation of the first rotation shaft, and a second output signal including a second sine wave signal and a second cosine wave signal output from a second magnetic sensor element in accordance with rotation of the second rotation shaft,

• the operation processing apparatus comprising:
• a phase difference calculation part that computes the relative phase difference between the first rotation shaft and the second rotation shaft from the first output signal and the second output signal based on Equation (1) below;
• and
• a torque calculation part that computes the torque from a relative twist angle that is expressed as a difference in rotational angles between the first rotation shaft and the second rotation shaft and that is found based on a correlation between the relative phase differences computed by the phase difference calculation part.
• [Equation 1]
• CPD=√{square root over ((SS1−SS2)2+(SC1−SC2)2)} (1)
• In Equation (1), CPD indicates the relative phase difference, SS1 indicates the first sine wave signal, SC1 indicates the first cosine wave signal, SS2 indicates the second sine wave signal and SC2 indicates the second cosine wave signal.