A wheel speed sensor for a utility vehicle, including: an active pulse sensor, a housing to at least partially enclose the active pulse sensor, and a protective cap to at least partially cover the housing; in which the wheel speed sensor has at least one component to adapt a temperature resistance capability of the wheel speed sensors so that the wheel speed sensor is usable in a high temperature environment.

A method for controlling closed loop operation of a capacitive accelerometer comprises applying first in-phase and anti-phase PWM drive signals, respectively, to a first pair of fixed capacitive electrodes and applying second in-phase and anti-phase PWM drive signals, respectively, to a second pair of fixed capacitive electrodes. A displacement of a proof mass relative to fixed capacitive electrodes is sensed by measuring a pickoff signal from the proof mass and adjusting the mark-space ratio of the first and/or second PWM drive signals to provide a restoring force on the proof mass that balances an applied acceleration and maintains the proof mass at a null position. The first and second PWM drive signals applied to the first and second pairs of fixed capacitive electrodes are offset in time from one another by an offset period.

A single sensing unit having two electrodes with a common thermal reference is positioned near the centroid of the inertial mass of a differential inductive accelerometer. As the mass is displaced a first sensor detects an increase in inductance while a second sensor detects a decrease in inductance. Significantly, the first and second sensors share a common thermal reference eliminating any thermal differential. As the sensor system is closely aligned with the centroid of the inertial mass the sensor system of the present invention reduces or eliminates any systemic error.

An electronic measuring device for measuring a physical parameter includes a differential analogue sensor formed from two capacitancesan excitation circuit of the differential analogue sensor providing to the sensor two electrical excitation signals which are inverteda measuring circuit which generates an analogue electrical voltage which is a function determined from the value of the sensor, and a circuit for compensating for a possible offset of the sensor, which is formed from a compensation capacitance, which is excited by its own electrical excitation signal. The excitation circuit is arranged in order to be able to provide to an additional capacitance of the compensation circuit its own electrical excitation signal having a linear dependence on the absolute temperature with a determined proportionality factor in order to compensate for a drift in temperature of an electrical assembly of the measuring device comprising at least the compensation capacitance.

A positioning apparatus includes: a reference device configured to provide a measured current motion angle of a vehicle; an inertial sensor configured to provide a current input angular rate of the vehicle and associated with at least one inertial sensor behavior parameter dependent on inertial sensor temperature; a temperature sensor configured to provide an input temperature variation of the inertial sensor on a time interval; and a digital estimator configured to recursively computing an estimated current motion angle of the vehicle and at least one previously estimated inertial sensor behavior parameter as function of: the measured current motion angle, a previously estimated motion angle, the current input angular rate, and the input temperature variation.

A failure determination circuit includes a switching circuit that receives a signal including an output voltage from a temperature sensor and a first reference voltage and outputs the signal in a time division manner, an A/D conversion circuit that A/D converts an output of the switching circuit, and a first determination circuit, and the first determination circuit determines a failure of the temperature sensor based on a signal based on a first digital signal obtained by A/D converting an output voltage from the temperature sensor by the A/D conversion circuit, a signal based on a second digital signal obtained by A/D converting the first reference voltage by the A/D conversion circuit, and temperature characteristics data based on a change in characteristics of the temperature sensor due to temperature and a change in characteristics of the first reference voltage due to temperature.

A sensor is compensated by selectively activating a temperature element to drive temperature within the thermal envelope encompassing the sensor towards an operating temperature and applying a compensation to output of the sensor based at least in part on the operating temperature. The initial ambient temperature is estimated and the operating temperature is selected from a set of predetermined temperatures based on the estimate. The current ambient temperature is estimated and a new operating temperature selected when the current ambient temperature is within a threshold of the operating temperature. Correspondingly, the temperature element is selectively activated to drive temperature within the thermal envelope towards the new operating temperature and an appropriate compensation is applied to the sensor output.

A method for compensating for gyroscope drift on an electronic device includes receiving by a data processing unit, measurement data from a gyroscope. The method includes computing, by the data processing unit, a compensation parameter by analyzing the measurement data received from the gyroscope with respect to variations in temperature of the gyroscope. The method includes compensating, by the data processing unit, the measurement data by correcting the measurement data with the computed compensation parameter. The compensation parameter is continuously validated to correct the measurement data with the compensation parameter. Further, the received measurement data is updated continuously based on the computed compensation parameter, independent of the gyroscope on the electronic device, thereby facilitating adaptive drift compensation.

A sensing system and method are provided. The sensing system includes a sensor unit that is configured to output a voltage having a magnitude that corresponds to a detected physical quantity and an amplification unit that is configured to amplify a magnitude in the output of the sensor unit to a constant gain. An offset removal unit is configured to remove a direct current (DC) offset from an output amplified by the amplification unit to generate a first detection signal. An inversion circuit unit is configured to invert the first detection signal to generate a second detection signal. A microcomputer is configured to then calculate the physical quantity detected by the sensor unit based on the first detection signal and the second detection signal.

An apparatus for measuring acceleration includes: a reference cavity having a first fixed reflecting surface and a second fixed reflecting surface; a sense cavity having a fixed reflecting surface and a non-fixed reflecting surface, the non-fixed reflecting surface being configured to be displaced when subject to an acceleration force; a light source to illuminate the reference and sense cavities; a controller to vary a wavelength of light emitted by the light source and/or an index of refraction of an optical medium of the cavities; a photodetector to detect light emitted by the reference and sense cavities; an interferometer sensor to measure using the detected light, for each variation of the wavelength of light and/or the index of refraction a reference displacement of the reference cavity and a sense displacement of the sense cavity; and a processor to calculate the acceleration using each of the reference displacements and the sense displacements.