An apparatus for determining an item of position information relating to a position of a magnetic field transducer relative to a position sensor. The position sensor is designed to generate at least one periodic measurement signal when the magnetic field transducer moves relative to the position sensor. A processing unit of the apparatus is designed to determine the position information based on a respective measurement signal value of a respective periodic measurement signal using a calibration function assigned to the respective periodic measurement signal. The assigned calibration function represents the respective periodic measurement signal using a Fourier series having a respective plurality of Fourier coefficients which differ from zero and are of an order greater than zero. The processing unit is designed to at least approximately solve the assigned calibration function for the respective measurement signal value in order to determine the position information.

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.

In order to correct the rotation angle value without an increase in the circuit size, a rotation period measurement unit measures a rotation period of a rotary shaft in which a rotation angle is detected by using a resolver that outputs a signal corresponding to the rotation angle of the rotary shaft. A rotation speed calculation unit calculates the rotation speed of the rotary shaft based on the rotation period. An acceleration calculation unit calculates the rate of change of the rotation speed per interval when a given rotation angle of the rotary shaft is divided into 2.sup.n+1 intervals, in which n is an integer of 1 or more. An estimated angle calculation unit calculates the rotation angle estimation value, assuming that the rotary shaft performs a uniform acceleration motion, based on the rotation speed and the rate of change of the rotation speed. A correction value calculation unit calculates the correction value of the rotation angle value converted from the output signal of the resolver. A correction value application unit generates a corrected angle value by applying the correction value to the rotation angle value.

An angle sensor can have a plurality of magnetic field sensing elements configured to detect a magnetic field and generate a respective plurality of magnetic field signals. In response to these magnetic field signals, a processor generates an uncorrected angle signal that is indicative of an angle of the magnetic field. An error corrector generates an error value using one or more of the previous samples of the uncorrected angle signal, and a summation element applies the error value to a current sample of the uncorrected angle signal to generate a corrected angle signal. The error corrector can generate the error value by applying a correction factor to a previous sample of the uncorrected angle signal, or by applying a correction factor to a predicted current sample of the uncorrected angle signal.

A position-measuring device includes a graduation carrier having a measuring graduation disposed thereon. At least one position sensor is configured to generate position-dependent measurement signals by scanning the measuring graduation. A processor is configured to process the position-dependent measurement signals into position signals. An interface is configured to transmit the position signals to subsequent electronics via at least one data channel. At least one motion sensor is configured to generate time-varying measurement signals. A signal analyzer is configured to analyze the measurement signals in the frequency domain dependent on parameters that are transmittable from the subsequent electronics to the interface unit, and to produce result data that is transmittable from the interface unit to the subsequent electronics.

A multi-turn absolute encoder, an encoding method and a robot are disclosed. The multi-turn absolute encoder includes a rotary shaft, a control circuit board, a magnet, a Hall sensor, a controller, a primary controller, a single-turn absolute encoder and a non-volatile memory. One side of the control circuit board is vertically provided with the rotary shaft. The magnet is connected to the rotary shaft and configured to synchronously rotate about the rotary shaft. The Hall sensor is configured to acquire turn count information of the rotary shaft upon power interruption. The primary controller is configured to calculate an absolute position information of the rotary shaft based on the turn count information of the rotary shaft, a relative position information of the rotary shaft and the absolute position information of the rotary shaft stored in previous power interruption.

There is provided a motor driving system in which an encoder sensor is configured to move with a driven object with respect to an encoder scale and output an encoder signal. A controller is configured to control a motor based on the encoder signal, thereby controlling movement of the driven object. The controller estimates an obstructing area. In the obstructing area, the encoder sensor reads a part of the encoder scale where an obstacle is adhered. The controller calculates a control error of the motor in the obstructing area based on the encoder signal output after the encoder sensor passes through the obstructing area, and determines a compensation amount of a controlling input value input during a period while the encoder sensor passes through the obstructing area.

An encoder signal processing device, a printer, a printer-equipped imaging apparatus, and an encoder signal processing method that can remove the effect of a noise signal mixed with an encoder signal and favorably deal with a case where an original pulse signal is lost from the encoder signal are provided. An effective detection period setting unit 523 sets an effective detection period for detecting a subsequent pulse signal, each time a pulse signal detection unit 522 detects a pulse signal from an encoder signal. The pulse signal detection unit 522 detects the pulse signal only within the set effective detection period. In a case where the pulse signal detection unit 522 does not detect the pulse signal within the effective detection period, a pulse signal generation unit 524 generates the pulse signal after the effective detection period.

A rotary encoder may include a magnet, a magnetic sensor, and a control part configured to calculate a rotation position of the rotor body based on an output signal outputted from the magnetic sensor. The control part includes a temperature detecting section configured to detect temperature of the magnetic sensor, an offset voltage calculation section configured to calculate an offset voltage of the magnetic sensor based on the output signal from the magnetic sensor, and a storage section which stores a slope and an intercept of a primary approximate expression calculated by a relationship between temperatures previously detected by the temperature detecting section and the offset voltages previously calculated by the offset voltage calculation section. The control part executes offset voltage estimate processing based on the slope and the intercept stored in the storage section and correction processing which corrects the output signal from the magnetic sensor.

A method for detecting a phase on a gear includes obtaining a first determination result indicating whether the gear has been detected at a first detection position. A second determination result indicating whether the gear has been detected at a second detection position is obtained. A third angle between the first and second angles is obtained. A third determination result indicating whether the gear has been detected at a third detection position is obtained. The first angle is replaced with the third angle when the third and first determination results are same, or the second angle is replaced with the third angle when the third and first determination results are different. The phase on the gear is detected based on an angle that is between the first angle and the second angle.