The subject of the present invention is a method for communicating a malfunction of a system for measuring speed and direction of rotation of a rotary shaft, said system comprising: a toothed wheel associated with said rotary shaft, called target (14), a magnetic field sensor (10′), measuring values (K, A) of the magnetic field (B, B′, B″) generated by the passage of the teeth (T1, T2 . . . Ti) in front of said sensor (10′) and delivering a signal (S, S′, S″) to processing means 13). According to the invention, the method comprises the following steps: step 1: comparison by the sensor between the measured values and predetermined threshold values of the magnetic field, step 2: if the measured values are below the predetermined threshold values, step 3: generation by the sensor of a coding on the signal, representative of the measured values, to communicate a malfunction of the system to the processing means.

A system and method for monitoring analog front-end (AFE) circuitry of an inductive position sensor. A redundant AFE channel is provided and alternatively utilized with a sine AFE channel or a cosine AFE channel of the AFE circuitry to obtain a voltage difference that may result in a detection angle error at the electronic control unit (ECU) of the inductive position sensor.

There is provided an absolute encoder advantageous in accuracy of an output thereof against a defect in a scale thereof. In the absolute encoder, a detector detects a part of an array of marks of the scale, and outputs a data sequence corresponding to the part. A processor stores information indicating a correspondence between each of a plurality of code sequences and an absolute coordinate of motion of the scale, and outputs information of the absolute coordinate based on the data sequence and the information. The processor detects an error of the data sequence, and performs rewriting of the information based on the detected error.

A Hall sensor has a Hall sensor element, which has multiple connection points spaced apart from one another. A supply source serves for feeding an exciter current into the Hall sensor element and is connected to a first and a second connection point of the Hall sensor element. The Hall sensor has a first and a second comparison device. The first comparison device has a first input connected to a third connection point of the Hall sensor element, a second input connected to a reference signal generator for an upper reference value signal, and an output for a first comparison signal. The second comparison device has a third input connected to the third connection point, a fourth input connected to a reference signal generator for a lower reference value signal, and an output for a second comparison signal. The outputs are connected to an evaluation device for generating an error signal as a function of the first and second comparison signal.

A testing apparatus and method for detecting faults in encoders are disclosed. The testing apparatus includes a signal conditioning circuit board that receives an encoder signal and a central processing unit in communication with the circuit board and configured to: check for faulty amplitude, check for signal symmetry, check for signal offset, and/or check for signal transmission rate. The testing apparatus includes a real-time controller for real-time signal processing and fault detection.

There is provided a light control circuit including a light detector, a frequency detector, an error amplifier, an NMOS driver and a light source. The frequency detector identifies a signal frequency according to detected voltage signals outputted by the light detector and generates a control signal accordingly. The NMOS driver changes a drive current of the light source according to an output of the error amplifier. The error amplifier changes a bandwidth thereof according to the control signal from the frequency detector to regulate a response time of the drive current of the light source.

A capacitive sensor includes a first conductive structure; a second conductive structure movable relative to the first conductive structure in response to an external force acting thereon, wherein the first and the second conductive structures form a first capacitor having a first capacitance that changes with a change in a distance between the first conductive structure and second conductive structure, wherein the first capacitance is representative of the external force; and a diagnostic circuit configured to detect a first leakage current in the capacitive sensor by measuring an first electrical parameter that is affected by the first leakage current and comparing the measured first electrical parameter to a first predetermined error threshold, wherein the diagnostic circuit is further configured to generate a first error signal in response to the measured first electrical parameter being greater than the first predetermined error threshold.

A method for sensor diagnostics in a seat suspension system includes: generating, by a rotational position sensor, based on a rotational position of an output shaft coupled to a suspension mechanism to move a vehicle seat relative to a vehicle body, an output signal including a sine output and a cosine output; determining, based on the sine output and the cosine output, a diagnostic indicator value; and determining, based on the diagnostic indicator value, an accuracy of the output signal to represent the rotational position of the output shaft. A second method determines accuracy of an output signal to represent a rotational position of the output shaft in a seat suspension system using the output signal and a motor position signal representing a rotational position of a motor shaft coupled to the output shaft such that rotation of the motor shaft causes rotation of the output shaft.

A system and method for monitoring analog front-end (AFE) circuitry of an inductive position sensor. A redundant AFE channel is provided and alternatively utilized with a sine AFE channel or a cosine AFE channel of the AFE circuitry to obtain a voltage difference that may result in a detection angle error at the electronic control unit (ECU) of the inductive position sensor.

An encoder abnormality diagnosis device configured to diagnose an abnormality in an encoder that outputs a cosine waveform and a sine waveform according to a rotation angle of an object includes a stop determination processing unit configured to determine whether the object is rotating or stopping, based on a change in a count value of a pulse signal obtained by pulsing of each of the cosine waveform and the sine waveform, a frequency measurement unit configured to measure a frequency of the pulse signal, and a frequency diagnosis unit configured to compare the frequency measured by the frequency measurement unit with a preset upper limit frequency when the stop determination processing unit determines that the object is stopping, and to determine that an abnormality has occurred in the encoder when the measured frequency exceeds the upper limit frequency.