Abstract: A phase difference film composed of a resin containing a copolymer including polymerization units A and B, the phase difference film including a cylindrical phase separation structure that generates a structural birefringence, the phase separation structure including a phase (A) having the polymerization unit A as a main component and a phase (B) having the polymerization unit B as a main component, and the phase difference film satisfying the following condition (1) or (2). Condition (1): D(A)>D(B) and f(B)>0.5, and a direction giving a maximum refractive index among in-plane directions and an orientation direction of a cylinder in the phase separation structure are parallel to each other. Condition (2): D(A)>D(B) and f(A)>0.5, and a direction giving a maximum refractive index among in-plane directions and an orientation direction of a cylinder in the phase separation structure are orthogonal to each other.

Abstract: A calibration method in which, a rotation angle calculation device (20, 30) calculates (S2) a rotation angle ?c based on a detection signal of a sensor, transmits (S3) rotation angle data Dc indicating the rotation angle ?c to a calibration device (40), and transmits (S3) time difference data Dt relating to a time difference after having captured the detection signal until transmitting the rotation angle data to the calibration device, and in which the calibration device measures (S1) a rotation angle ?r, clocks (S1, S4) a measurement time tm at which the rotation angle ?r is measured and a transmission time tt of transmitting or receiving the rotation angle data, and acquires (S5, S6) calibration data Dc of the rotation angle data by comparing the rotation angle ?r measured at a time tc2 obtained by going back in time from the transmission time tt by the time difference after having captured the detection signal until transmitting the rotation angle data and the rotation angle data Da with each other.

Abstract: A calibration method in which, a rotation angle calculation device (20, 30) calculates (S2) a rotation angle ?c based on a detection signal of a sensor, transmits (S3) rotation angle data Dc indicating the rotation angle ?c to a calibration device (40), and transmits (S3) time difference data Dt relating to a time difference after having captured the detection signal until transmitting the rotation angle data to the calibration device, and in which the calibration device measures (S1) a rotation angle ?r, clocks (S1, S4) a measurement time tm at which the rotation angle ?r is measured and a transmission time tt of transmitting or receiving the rotation angle data, and acquires (S5, S6) calibration data Dc of the rotation angle data by comparing the rotation angle ?r measured at a time tc2 obtained by going back in time from the transmission time tt by the time difference after having captured the detection signal until transmitting the rotation angle data and the rotation angle data Da with each other.

Abstract: A detection signal correction method includes: calculating a rotation angle of a rotation shaft of a motor, based on a detection signal of a sensor; calculating a steering velocity of a steering shaft based on the rotation angle; calculating an error of the detection signal; and correcting the error of the detection signals when the steering velocity is equal to or greater than a steering velocity threshold value and the error of the detection signal is equal to or greater than an error threshold value.

Abstract: A phase adjustment method for a rotation angle sensor configured to detect a rotation angle of a rotor of a brushless motor, the phase adjustment method including: measuring a first rotation speed and a second rotation speed when the brushless motor is driven with a same torque command current to rotate clockwise and counterclockwise, respectively, on a basis of the rotation angle of the rotor detected by the rotation angle sensor; and calculating a correction value to correct a phase of the rotation angle sensor so that a rotation speed difference between the first rotation speed and the second rotation speed decreases.

Abstract: A calibration method in which, a rotation angle calculation device calculates a rotation angle based on a detection signal of a sensor, transmits rotation angle data indicating the rotation angle to a calibration device, and transmits time difference data relating to a time difference after having captured the detection signal until transmitting the rotation angle data to the calibration device, and in which the calibration device measures a rotation angle, clocks a measurement time at which the rotation angle is measured and a transmission time of transmitting or receiving the rotation angle data, and acquires calibration data of the rotation angle data by comparing the rotation angle measured at a time obtained by going back in time from the transmission time by the time difference after having captured the detection signal until transmitting the rotation angle data and the rotation angle data with each other.

Abstract: A detection signal correction method includes: calculating a rotation angle of a rotation shaft of a motor, based on a detection signal of a sensor; calculating a steering velocity of a steering shaft based on the rotation angle; calculating an error of the detection signal; and correcting the error of the detection signals when the steering velocity is equal to or greater than a steering velocity threshold value and the error of the detection signal is equal to or greater than an error threshold value.

Abstract: A calibration method in which, a rotation angle calculation device calculates a rotation angle based on a detection signal of a sensor, transmits rotation angle data indicating the rotation angle to a calibration device, and transmits time difference data relating to a time difference after having captured the detection signal until transmitting the rotation angle data to the calibration device, and in which the calibration device measures a rotation angle, clocks a measurement time at which the rotation angle is measured and a transmission time of transmitting or receiving the rotation angle data, and acquires calibration data of the rotation angle data by comparing the rotation angle measured at a time obtained by going back in time from the transmission time by the time difference after having captured the detection signal until transmitting the rotation angle data and the rotation angle data with each other.