A servo motor controller capable of eliminating inconvenience that the position of a shaft or the like of a servo motor is detected or set erroneously due to influence of noise or the like is provided. A servo motor controller that detects Z-phase signals of an incremental-type encoder that detects rotation of a servo motor to perform driving control of the servo motor includes: a position detection unit that detects a reference position of a rotating shaft of the servo motor on the basis of the Z-phase signal of the encoder; a signal interval detection unit that measures intervals of a plurality of detected Z-phase signals; and an abnormality determination unit that determines that the Z-phase signal is abnormal when the interval measured by the signal interval detection unit is equal to or larger than a prescribed threshold.

A resolver disposed to monitor a rotatable member is described, along with an associated method for evaluating an output signal therefrom. The method for monitoring the resolver includes supplying an excitation signal to the resolver, and monitoring, at an oversampling rate, first and second output signals from the resolver. An oversampling routine is executed to determine averages of the first and second output signals from the resolver. A demodulation angle error is determined based upon the first and second output signals from the resolver, and provided as feedback. A position of the resolver is also determined based upon the first and second output signals from the resolver.

An encoder for detecting a rotation angle of an object of detection includes: a main circuit including a rotational speed obtaining portion configured to obtain a rotational speed of the object of detection; a backup battery for supplying power to the main circuit while the main circuit is disconnected from a main power-supply circuit; a current obtaining portion configured to obtain a consumption current of the backup battery as a backup current while the electric power is being supplied from the backup battery to the main circuit; and a current abnormality determining portion configured to determine that the backup current is abnormal if the backup current is larger than a given current value when the rotational speed of the object of detection obtained by the rotational speed obtaining portion is a given rotational speed.

The present invention relates to a sensor device comprising four or more sensor elements. A controller comprising a control circuit controls the sensor elements to measure an environment attribute, produces more than two values corresponding to the measurement and compares the values to determine a fault. The more than two values are obtained by different combinations of sensor elements that have at least one sensor element in common and one sensor element that is not in common. The values can be measured in different coordinate systems and the control circuit can convert the field vectors into a common coordinate system.

A linear position detecting device applied to a linear motion system for motion measurement is provided. The linear position detecting device comprises a coding element and a detecting element corresponding to the coding element for retrieving the signal of the coding element to provide the position information. The coding element comprises a base, a first coding unit and a second coding unit wherein the base comprises an axial direction parallel to a length of the base, and a radial direction perpendicular to the axial direction. The first coding unit is configured on the base and comprises a plurality of first tracks extended along the axial direction and alternately arranged along the radial direction. The second coding unit is configured on the base and adjacent to the first coding unit, and comprises a plurality of second tracks wherein the second tracks are extended along the radial direction and alternately arranged along the axial direction.

Provided are a failure determination device and method for a rotating machine control device, which are capable of detecting failure of a sensor configured to detect a rotational position of a rotating machine while the rotating machine is in operation. A rotation angle estimator calculates a rotation angle estimation value. A relationship between the rotation angle estimation value (est), and a first angle detection value (1) and a second angle detection value (2), which are obtained from output signals of angle sensors configured to detect a rotational position of a rotating machine, is monitored while the rotating machine is in operation. In this manner, failure of the angle sensors, which are configured to detect the rotational position of the rotating machine, can be always detected even while the rotating machine is in operation.

The invention relates to a crankshaft, transmission or camshaft sensor (10) for a motor vehicle, intended for being connected to an engine control unit (30) by a cable (20). The sensor comprises a processing module (17) and a voltage-modifying circuit (18) configured to generate an output signal via an output port (12) of the sensor (10) allowing a diagnosis module (36) of the engine control unit (30) to detect and identify faults of the sensor (10) or the cable (20). In particular, the processing module (17) is configured to provide on its output port (172), when the toothed target (14) is immobile, a predetermined pattern representing the fact that the toothed target (14) is immobile, this predetermined pattern corresponding to a status change of the output port (172) of the processing module (17) with a predetermined time and repeated periodically. The invention likewise relates to a diagnosis system (1) comprising such a sensor (10), a cable (20) and an engine control unit (30). The invention also relates to a diagnosis method (50) implemented by said diagnosis system (1).

A position detection method includes obtaining a first phase value of a first signal that repetitively changes by a first cycle number, a second phase value of a second signal that repetitively changes by a second cycle number larger than the first cycle number, and a third phase value of a third signal that repetitively changes by a third cycle number larger than the second cycle number, selecting one cycle corresponding to the first phase value from cycles of the second cycle number, selecting one cycle corresponding to the second phase value and the cycle selected from the cycles of the second cycle number, obtaining a fourth phase value of the third signal corresponding to the second phase value of the cycle selected from the cycles of the second cycle number, and obtaining a position of the scale by using the third phase value and the fourth phase value.

A monitoring system is provided for monitoring the axial position of a rotating shaft. The system includes first and second, axially adjacent, phonic wheels which are formed from respective axially adjacent portions of a unitary annular body and mounted coaxially to the shaft for rotation therewith. The first and second phonic wheels have respective first and second circumferential rows of teeth. The system further includes a sensor configured to detect the passage of the first row of teeth by generating a first alternating measurement signal component, and to detect the passage of the second row of teeth by generating a second alternating measurement signal component. The sensor generates a signal having both the first and the second alternating measurement signal components when axially positioned midway between the first and second phonic wheels. The teeth of the first and second rows are configured such that the first alternating measurement signal component generated by the sensor has an identical frequency to the second alternating measurement signal component generated by the sensor. The first and second rows of teeth are angularly misaligned such that the first and second alternating measurement signal components are phase shifted relative to each other. Axial displacement of the shaft causes the signal generated by the sensor to vary the amplitude of the first component relative to the amplitude of the second component whereby the axial position of the shaft can be monitored.

Provided is a sensor control apparatus including a main board, a first sensor, a second sensor, and a third sensor, which are connected in series to the main board. The first sensor includes a diagnosis unit configured to perform a failure diagnosis of each of an LED, a phototransistor, and an LED controller. In a case where a failure is detected, the diagnosis unit electrically isolates the first sensor from the series connection, and supplies a power supply voltage to the second sensor.