A method of biasing and reading-out a passive resistive sensor structure having two excitation nodes and two readout nodes, comprises the steps of: a) determining a first state of a first capacitor corresponding to a first amount of charge biasing the sensor structure such that a biasing current flows through said first capacitor during a first time interval determining a second state of the first capacitor corresponding to a second amount of charge integrating or averaging the readout signal during a second time interval related to the first time interval, thereby obtaining an integrated or averaged readout signal determining the sensor readout signal based on the integrated or averaged readout signal and a change in state of the first capacitor.

A position measuring device includes: a graduation carrier on which a measuring graduation is provided; a scanning unit for generating position-dependent scanning signals by scanning the measuring graduation; and a signal processing unit for processing the scanning signals into position signals. A monitoring unit is provided, to which at least one signal to be monitored is supplied, and by which a modification signal is able to be output to a modification unit based on the monitoring of the signal to be monitored. At least one position signal is supplied to the modification unit, and the position signal is able to be modified by the modification unit for the transmission of at least one status report and able to be output as output signal to subsequent electronics. The modification is implemented based on the modification signal by adding a disturbance variable to the at least one position signal.

A correction apparatus for an angle sensor includes a correction processing unit, an indicator value generation unit, and a correction information determination unit. The correction processing unit performs correction processing on a plurality of detection signals to reduce an error of a detected angle value. The details of the correction processing are determined according to correction information. The indicator value generation unit generates, on the basis of the plurality of detection signals, an indicator value having a correspondence with the error of the detected angle value. The correction information determination unit generates an estimated indicator value using a function that takes one or more values each having a correspondence with the correction information as one or more variables, and determines the correction information by adaptive signal processing so as to reduce the difference between the indicator value and the estimated indicator value.

A position-encoding device includes a sensing device, a filtering device, a calibrating device and a compensating device. The sensing device senses the motion of a moving device to generate first and second signals. The filtering device filters the first and second signals to generate first and second filtering signal. The calibrating device captures the first and second filtering signals to obtain time and phase information of the first and second filtering signals, performs gain and offset calibration on the first and second filtering signals, and performs a phase calibration on the first and second filtering signals through first, second feedback signals and the time and phase information of the first and second filtering signals to generate first and second calibrating signals. The compensating device compensates for the first and second calibrating signals according to a lookup table, so as to generate first and second position encoding signals.

An encoder comprises first and second sensors which reads first and second tracks, the first and second sensors being arranged in a radial direction to face each other, and a processor which generates a first position signal based on first and second periodic signals based on a signal obtained by reading the first and second tracks by the first sensor, and generates a second position signal based on third and fourth periodic signals based on a signal obtained by reading the first and second tracks by the second sensor, wherein the processor generates an absolute position signal indicating an absolute position of at least one of the scale, the first sensor, or the second sensor based on the first and second position signals and the first and third periodic signals.

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.

A rotation sensing apparatus includes a detected part including a first pattern portion with a plurality of first patterns and a second pattern portion with a plurality of second patterns; a first sensor disposed opposite to the first pattern portion; a second sensor disposed opposite to the second pattern portion; a third sensor disposed at an angle from the first sensor and disposed opposite to the first pattern portion; a fourth sensor disposed at an angle from the second sensor and disposed opposite to the second pattern portion; and a rotation information calculation circuit to calculate rotation information regarding rotation of a rotating body based on first, second, third, and fourth oscillation signals associated with outputs of the first, second, third, and fourth sensors and to compensate for nonlinearity of a differential signal generated based on the first, second, third, and fourth oscillation signals.

There is provided an interpolation circuit of an optical encoder including a phase shifter circuit, two multiplexers. two digital circuits and four comparators. The phase shifter circuit receives signals sequentially have a 90 degrees phase shift and outputs multiple phase shifted signals. Each of the two multiplexers receives a half of the multiple phase shifted signals and outputs two pairs of phase shifted signals, each pair having 180 degrees phase difference, respectively to two comparators connected thereto. Each of the two digital circuits controls the corresponding multiplexer to select the two pairs of phase shifted signals from the half of the multiple phase shifted signals.

A sensor device for determining a position .sub.1 of a rotor of an electrical machine, for example an electric motor or electric generator. The sensor device comprises a number r of sensors, which detect the magnetic field generated by the rotor and/or a permanent magnet rotating with the rotor, and an electronic circuit which is configured to detect and digitalize the sensor signals a.sub.1 to a.sub.r and to form a signal vector {right arrow over (a)}=(a.sub.1, . . . , a.sub.r), to form a measurement vector {right arrow over (q)} according to a predetermined linear function g to {right arrow over (q)}=g({right arrow over (a)}), to calculate a vector {right arrow over (p)}=M.sub.rot1.Math.{right arrow over (q)}, wherein {right arrow over (p)} is a 2-component vector with the components p.sub.1 and p.sub.2 and M.sub.rot1 is a 2n matrix, and to determine the position .sub.1 of the rotor to .sub.1=a tan 2(p.sub.2, p.sub.1). The invention further concerns a control device for an electric motor with such a sensor device.

An encoder signal processing device includes a position data acquisition unit, an error data calculation unit that calculates error data in a predetermined number of position data in one cycle, and a compensation unit that compensates the position data based on the calculated error data, in which the error data calculation unit calculates first error data in the predetermined number of position data sampled at first predetermined time intervals Tn in one cycle, defines the first error data as the error data, calculates second error data in position data sampled at second predetermined time intervals Tk in each of the first predetermined time intervals Tn, and changes a time interval of the error data without increasing or decreasing the predetermined number of error data by replacing second error data closest to a local extremum or inflexion point in error characteristics of the first and second error data with the first error data.