A calibrator includes: a position calculator which calculates a relative position between a first detector and a second detector on the basis of detection signals acquired respectively from the first detector, the second detector, and a third detector positioned with respect to a scale attached to a rotating body; and an error calculator which calculates error information on rotational position information of the rotating body on the basis of the relative position calculated by the position calculator as well as the detection signals.

A magnetic field sensor comprises at least one magnetic field sensing element configured to generate a measured magnetic field signal responsive to an external magnetic field; a diagnostic circuit configured to generate a diagnostic signal, wherein the diagnostic signal is not dependent on a measured magnetic field; a signal path comprising an amplifier and an analog-to-digital converter for processing the measured magnetic field signal to generate a sensor output signal indicative of the external magnetic field during a measured time period and for processing the diagnostic signal during a diagnostic time period; and a switch coupled to receive the measured magnetic field signal and the diagnostic signal and direct the measured magnetic field signal to the signal path during the measured time period and direct the diagnostic signal to the signal path during the diagnostic time period.

Disclosed is a method for estimating angular errors of coders for a looped system including a rotating actuator and an angle coder producing a position measurement signal, and including a calculation device controlling the actuator, the calculation device receiving a setpoint signal, as well as the measurement signal, for looping, the calculation device calculating in a corrector a control signal. In a test phase, a specific corrector C.sub.ω.sub.rj(q) is synthesised for constant rotation speed ω.sub.rj, the corrector having substantially zero gain at the frequency and harmonics, resulting in opening the loop at the frequencies, a matrix relation is established between position measurements and a function of parameters characterizing the coder errors and the torque ripples, the test phase repeats with different speeds, the matrix relations are concatenated producing an identifiable global matrix relation, the encoder error and torque ripple parameters are estimated by resolution of the global matrix relation.

Provided is a calibration apparatus including: an acquisition unit for acquiring a detection position of a mobile body for each actual position of the mobile body; a calculation unit for calculating, for a detection position of each actual position of the mobile body, an error between a slit position signal for detecting a slit position and an ideal slit number corresponding to the actual position; a determination unit for determining whether two or more actual positions having at least partially different slit numbers in units of first slits of a predefined number correspond to a same detection position; and a generation unit for generating, in response to the two or more actual positions corresponding to a same detection position, a correction value for correcting an error by a magnitude between errors at the two or more actual positions with respect to the slit position signal at the detection position.

For determination of the position of a movable component with a plurality of position magnets relative to a stationary component with a plurality of position sensors, it is provided that the sensor responses are detected for a group of position sensors in the region of the movable component, sensor model responses of the group of position sensors are determined from a sensor model for a plurality of assumed different relative positions of the movable component relative to the stationary component, the sensor model responses are compared with the sensor responses and the assumed relative position with the smallest deviation between the sensor model responses and the sensor responses is used as the relative position of the movable component.

A method of correcting a position reading from a position sensing arrangement. The position sensing arrangement is suitable for sensing the position of a revolute joint of an articulated structure, and comprises a disc having a magnetic ring with magnetic pole pairs and a magnetic sensor assembly comprising a magnetic sensor array for detecting the magnetic pole pairs of the magnetic ring. The method comprises: for each pole pair of the magnetic ring, taking a calibration pole pair position reading with the magnetic sensor array, and generating a pole pair correcting function by comparing the calibration pole pair position reading with a model pole pair position reading; averaging the pole pair correcting functions of the pole pairs of the magnetic ring to generate an average pole pair correcting function for the magnetic ring; taking a position reading with the magnetic sensor array, the position reading comprising a plurality of pole pair position readings; and generating a corrected position reading by deducting the average pole pair correcting function from each pole pair position reading.

A sensor for an encoder. The sensor includes a sensing circuit, an active setting module, an inactive setting module, and a sensor interface. The sensing circuit module is configured to generate an output signal related to a sensed characteristic. The active setting module includes a first pole width setting. The first pole width setting is associated with a first pole width for the encoder. The first pole width setting is accessible by the sensing circuit module. The inactive setting module includes second pole width setting. The second pole width setting is associated with a second pole width for the encoder. The second pole width setting is not accessible by the sensing circuit module. The sensor interface is configured for retrieving the second pole width setting from the inactive setting module and writing the second pole width setting to the active setting module.

A linear encoder can have a mass embodiment having a position code marking, a read head having a calibration means, and a control and analysis unit, and calibration method for calibrating a position code made of code elements using the read head. The read head has a sensor unit having at least two detection reference points, the detection distance of which establishes at least one standard with high precision. In the scope of the calibration method, calibrated position values are prepared for code elements with the aid of the standard, which is determined with high precision, and are stored in the control and analysis unit.

An actuator position sensing system for sensing a position of an actuator. The actuator position sensing system includes a first sensor for detecting a position of a first moveable portion of the actuator; a plurality of second sensors each being configured for detecting a position of a second moveable portion of the actuator; and a controller connected to the first sensor and the plurality of second sensors. The controller is configured to calculate a difference between (i) a position of the second movable portion as calculated based upon the data transmitted from the first sensor, and (ii) a position of the second movable portion as calculated based upon the data transmitted from one or more of the plurality of second sensors. A motor is connected to the first movable portion and the controller, and the motor is configured to move the first moveable portion based upon the calculated difference.

In a position detector for converting, into position information, two signals shifted in phase by 90 degrees from each other, a phase correction value calculator for calculating a phase correction value for correcting a phase difference between the two signals calculates a phase change value representing a change in the phase correction value, to find a next phase correction value based on the phase change value and a present phase correction value. A virtual change value calculator calculates, based on second-order components obtained by Fourier analysis of a radius value, a virtual phase change value representing another change in the phase correction value obtained when changes in offset and amplitude ratio are ignored, and a virtual amplitude change value representing a change rate in an amplitude ratio correction value obtained when a change in the phase difference is ignored.