A motor has a rotor that rotates in response to one or more alternating current input signals. A position sensor is adapted to generate a substantially saw-tooth waveform indicative of a position of the rotor. A primary processing module or data processor is capable of providing position data and speed data for the rotor based on the substantially saw-tooth waveform. A notch filter can reject one or more selected frequency components in the substantially saw-tooth waveform to reduce distortion off the substantially saw-tooth waveform that would otherwise tend to cause inaccuracy in the provided position data and speed data.

A correction apparatus for an angle sensor includes a correction unit for performing first correction processing on a first detection signal and performing second correction processing on a second detection signal. The first correction processing is processing for combining the first detection signal and a first correction value to generate a first corrected detection signal. The second correction processing is processing for combining the second detection signal and a second correction value to generate a second corrected detection signal. The first correction value has a first amplitude and varies with a first period. The second correction value has a second amplitude and varies with a second period. The first and second amplitudes are of the same value. The first and second periods are of the same value equal to ⅓ or ⅕ of the period of an ideal component of each of the first and second detection signals.

An information processing apparatus includes an acquisition unit configured to acquire a first phase signal and a second phase signal that are acquired by measuring a rotation of a moving object, and a calculation unit configured to calculate a rotational angle by an iterative calculation so as to satisfy a relational expression bearing an arctangent. The relational expression bearing the arctangent uses a first cosine wave and a second cosine wave at a higher harmonic of the first cosine wave for the first phase signal, and a first sine wave and a second sine wave at a higher harmonic of the first sine wave for the second phase signal. The first phase signal and the second phase signal may, for example, be analog signals having a wave shape.

An angle sensor includes a plurality of magnetic sensors and a processor. The plurality of magnetic sensors generate a plurality of detection values representing directions of a composite magnetic field, which is a composite of a magnetic field to be detected and a noise magnetic field. The processor assumes a group of estimated unknowns. The group of estimated unknowns is a set of estimated values of a first, a second, and a third unknown. The first unknown corresponds to an angle detection value. The second unknown corresponds to the direction of the noise magnetic field. The third unknown corresponds to the strength of the noise magnetic field. The processor executes a process for determining the group of estimated unknowns a plurality of times, and assumes an estimated value of the first unknown in the last determined group of estimated unknowns as the angle detection value.

An absolute-type linear encoder absolute signal consistency correction method, related to the field of absolute-type linear encoder measurements, for solving the problem of narrow linear range for photoelectric responses and large signal dispersion found in an existing consistency correction method for a photoelectric conversion component and a processing circuit thereof. The correction method allows for enhanced absolute signal quality and increased system measurement precision.

Methods and apparatus disclosed herein implement or otherwise embody a technique that compensates for cyclic position errors in encoder-based position detection, wherein the cyclic position errors arise from the presence of harmonic components in the encoder signals relied upon for position determination. Using position-domain compensation for errors arising in the encoder domain offers computational simplicity and impressive compensation performance, even when compensating for a plurality of higher harmonics in the encoder signals, e.g., third harmonic, fifth harmonic, etc. Consequently, even high-precision position monitoring or control can use relatively inexpensive types of encoders known to output encoder signals having significant harmonic components.

A current source sensor delivers detection information in the form of an intermediate signal by selectively applying a low-level or high-level current to a communication bus depending on the passage of a mobile target, the sensor including a sensitive portion detecting the passage of a of the mobile target, an electronic module controlling and shape signals coming from the sensitive portion, an embedded intelligence module designed, inter alia, to receive information from another sensor through a first signal present on the communication bus, the first signal being the sum of the abovementioned intermediate signal generated by the sensor and of another intermediate signal generated by the other sensor, wherein the embedded intelligence module is adapted to modify a first low level and a first high level of the intermediate signal, respectively, into a second low level and into a second high level depending on a the first signal.

A signal processing device for processing a measurement signal in a motor vehicle, wherein the measurement signal relates to a measurement variable which can change over time with sequential measurement values, including: a first signal processing unit for calculating the measurement variable which can change over time from the measurement signal; a second signal processing unit for processing the measurement variable which can change over time in order to obtain a processed measurement variable; a third signal processing unit for calculating a change rate of the measurement variable which can change over time, the third signal processing unit being designed to output an additional measurement signal which indicates the change rate; and a communication interface which is designed to combine the processed measurement variable and the additional measurement signal into a composite transmission signal and to transmit the composite transmission signal.

To reduce the error in a rotational angle detected by a rotational angle detection apparatus, provided is a rotational angle detection apparatus that detects a rotational angle of a magnetic field generation source, including a magnetic field detection apparatus that detects magnetic field components in at least two directions, and outputs resulting detection data; a correction value calculating section that calculates correction values for correcting an angle error of the rotational angle, based on a steady-state error that does not depend on rotation of the magnetic field generation source; and an angle computing section that calculates the rotational angle of the magnetic field generation source based on the detection data and the correction values, and outputs an angle signal indicating the rotational angle.

A position sensing device for measuring a position, comprises a position sensing device for measuring a position; a plurality of sensors arranged to produce sense signals each being a function of an input phase representative of a position to be measured; a combiner circuit arranged to generate an error signal by combining the sense signals according to an array of weight factors; a processing block including a loop filter to filter the error signal and arranged to output a phase value representative of the position; and a feedback loop comprising a feedback signal unit arranged for receiving the output phase value and for adjusting based on the received output phase value of the array of weight factors.