Implementations of a resolver sensor system may include a signal amplifier portion configured to be coupled to a magnetoresistive sensor coupled with a movable element where the signal amplifier portion configured to receive a sine signal and a cosine signal from the magnetoresistive sensor; and a sensor offset canceling portion coupled with a signal amplifier portion. The sensor offset canceling portion may be configured to generate a direct current offset correction signal to the signal amplifier portion which uses two or more amplifiers included in the signal amplifier portion to receive the sine signal and the cosine signal and to generate corresponding adjusted digital sine and cosine signals. The signal amplifier portion may be configured to provide the adjusted digital sine signal and the adjusted digital cosine signal to one of the servo signal processor or the system controller for use in determining a position of the movable element.

A magnetic sensor system includes a magnetic device and a signal processing circuit. The device generates first to third detection signals corresponding to components in three directions of a magnetic field generated by a magnetic field generator that is able to change its relative position with respect to the device. The circuit includes a longest segment extraction section and a midpoint coordinate computing section. With coordinates that represent a set of values of the first to third detection signals at a certain timing in an orthogonal coordinate system being taken as a measurement point, the longest segment extraction section extracts a first point and a second point that define a line segment having the greatest length among a plurality of measurement points at a plurality of timings. The midpoint coordinate computing section determines coordinates of a midpoint of the line segment defined by the first and second points.

In one aspect, an angle sensor includes analog circuitry configured to generate an analog value having a tangent value, an analog-to-digital converter configured to convert the analog value to a digital value and digital circuitry configured to receive the digital value. The analog circuitry includes a plurality of magnetoresistance elements that include a first magnetoresistance element configured to provide a cosine value indicative of a magnetic field along a first axis and a second magnetoresistance element configured to provide a sine value indicative of the magnetic field along a second axis orthogonal to the first axis. The tangent value is determined by the cosine and sine values. The digital circuitry includes an angle processor configured to use the digital value and a fixed value in an arctangent algorithm to generate an angle of a direction of the magnetic field.

The present invention provides a rotation angle detection method and device thereof. The method includes calculating an estimated value of a rotation angle of a motor shaft during rotation according to a second rotation angle; determining an actual range of the rotation angle according to the estimated value of the rotation angle and a detection error of the second angle sensor; determining optional values of the rotation angle based on a relative relationship between a first rotation angle and the estimated value; determining an actual rotation angle of the motor shaft, based on a value falling within the actual range of the rotation angle among the optional values, and determining an actual rotation angle of the output shaft according to the actual rotation angle of the motor shaft. The present invention can improve the measurement accuracy of the rotation angles of the output shaft of the rotating mechanism.

An exemplary encoder assembly includes a substrate, a first encoder, and a second encoder. The substrate has two or more position sensors, each position sensor being configured for detecting a rotary position of a shaft or other rotating element of a machine. The first encoder includes at least one first position sensor of the two or more position sensors. The at least one first position sensor is disposed on the substrate for off-axis alignment with the shaft or other rotating element of the machine. The second encoder includes a second position sensor of the two or more position sensors, the second position sensor being disposed on the substrate for on-axis or off-axis alignment with the shaft or other rotating element of the machine. Each position sensor is configured to detect different or common signal types, and a signal type of the second position sensor excludes optical signals.

A rotation detection device includes a plurality of detectors each including a plurality of calculators respectively calculating a detection value. A control unit of the rotation detection device monitors abnormality of detection values respectively detected by the plurality of detectors, and, when determining abnormality, identifies a calculator calculating an abnormal detection value based on a result of comparison between the detection values of the plurality of calculators. Then, the control unit continues calculation of an absolute angle by using the detection values from the calculators other than the identified calculator.

In one aspect, an angle sensor includes analog circuitry configured to generate an analog value having a tangent value, an analog-to-digital converter configured to convert the analog value to a digital value and digital circuitry configured to receive the digital value. The analog circuitry includes a plurality of magnetoresistance elements that include a first magnetoresistance element configured to provide a cosine value indicative of a magnetic field along a first axis and a second magnetoresistance element configured to provide a sine value indicative of the magnetic field along a second axis orthogonal to the first axis. The tangent value is determined by the cosine and sine values. The digital circuitry includes an angle processor configured to use the digital value and a fixed value in an arctangent algorithm to generate an angle of a direction of the magnetic field.

In a quick measurement module provided by the present invention, a first distance sensing unit and a second distance sensing unit are provided individually on a movable seat, so that when the movable seat is displaced along a linear shifting axis, the first distance sensing unit senses the distance from the first reference plane, and meanwhile, the second distance sensing unit senses the distance from the second reference plane, so as to sense the linearity accuracy in movement of the movable seat with respect to the first reference plane and the second reference plane. The first reference plane and the second reference plane are spaced apart by an angle other than a right angle, so that the linearity accuracy in movement in the two different planes, such as the horizontal linearity accuracy and vertical linearity accuracy, of the movable seat can be obtained through sensing.

Provided is an encoder, which is provided in a driving apparatus comprising a motor section configured to drive a first displacement section, which is connected to a fixed section via an elastic body, and a transmission section configured to convert a displacement of the first displacement section and transmit the displacement to the second displacement section, comprising: a first detector configured to detect first displacement information of the first displacement section; a second detector configured to detect second displacement information of the second displacement section; a third detector configured to detect third displacement information of the motor section relative to the fixed section; and a computing section configured to obtain information related to a driving amount of the motor section using the first displacement information and the second displacement information, and obtain information of a load on the motor section using the third displacement information.

The rotation sensor includes a plurality of magnetic sensors for outputting a sine wave signal and a cosine wave signal corresponding to an electrical angle of rotation of the rotating body, and the magnetic sensors are arranged at equal intervals and in a circumferential direction of the rotating body apart from the outer periphery of the rotating body, and are fixed in position so as to detect a change in magnetic field caused by the change in the rotational position of the rotating body due to the rotation of the rotating body. The rotation sensor includes an arithmetic unit, which receives sine wave signals and cosine wave signals from a plurality of magnetic sensors, and adds and subtracts sine wave signals and cosine wave signals according to a predetermined rule, thereby cancels out the high-order components contained in sine wave signals and cosine wave signals.