Assessing and removing jitter from tachometer signals enhances the performance of condition monitoring systems where accurate tachometer signals are needed. A system as disclosed herein can be designed and configured to have a low order of operations, so as to allow for implementation on low cost microcontrollers, which can be important for bused, distributed monitoring systems in which the tachometer zero crossing data is collected at a tachometer sensor and then broadcast to other remote sensors needing that information for vibration or other advanced analysis. Moreover, for monolithic architecture systems (e.g., a centralized processing and control architecture), the low order of operation and small software code base allows the system to be a simple/low cost addition to existing monitoring systems.

A sensor system and method of using the system synergistically to improve the accuracy and usefulness of measured results is described. The system is comprised of electronically linked components that act as markers to trigger events, producers that gather data from sensors and aggregators that combine the data from a plurality of producers using triggers from marker devices to select the data of interest. The system is shown to be applicable to selection of data regions of interest and to analysis of the data to improve accuracy. The analysis of the data of any particular sensor within the system makes use of extrinsic data, being data generated by other sensors and intrinsic data, that is data or data limits that are known to be true from nature, laws of physics or just the particular information the user wants to acquire. The system is demonstrated on the analysis of Doppler radar measurements of a thrown object.

A sensor system and method of using the system synergistically to improve the accuracy and usefulness of measured results is described. The system is comprised of electronically linked components that act as markers to trigger events, producers that gather data from sensors and aggregators that combine the data from a plurality of producers using triggers from marker devices to select the data of interest. The system is shown to be applicable to selection of data regions of interest and to analysis of the data to improve accuracy. The analysis of the data of any particular sensor within the system makes use of extrinsic data, being data generated by other sensors and intrinsic data, that is data or data limits that are known to be true from nature, laws of physics or just the particular information the user wants to acquire. The system is demonstrated on the analysis of Doppler radar measurements of a thrown object.

A method of determining the speed of the wind to be taken into account for determining a maximum authorized takeoff weight of an aircraft. A measured speed TAS.sub.mes of the local wind is calculated from at least one current speed TAS.sub.inst of the local wind and an observed speed TAS.sub.obs of the local wind on the basis of weather observations and on the basis of a heading value. The measured speed TAS.sub.mes is compared with the observed speed TAS.sub.obs in order to determine a calculated speed TAS.sub.perfo of the local wind while also making use of at least one instability criterion of the local wind as supplied by the weather observations and weather forecasts. The calculated speed TAS.sub.perfo is then for taking into account in order to optimize the maximize authorized takeoff weight of the aircraft.

A method and a device for measuring the torque in the drivetrain (1) of a wind power plant is described, having at least two incremental encoders (7, 8) which are positioned at two different positions on at least one shaft (3) of the drivetrain (1) and which each supply periodic rotational signals, wherein the phases of the rotational signals are evaluated in order to detect a phase shift, and a torque of the shaft (1) is determined from the phase shift. The detected phase shift is corrected as a function of a zero load phase shift (A.sub.Zero), using a rigidity factor K, wherein, in order to determine the zero load phase shift (A.sub.Zero) and the rigidity factor K, in-situ calibration is carried out before and/or between the torque-determining processes. The in-situ calibration is performed at zero load of the wind power plant, i.e. below a rated rotational speed and with a generator torque equal to zero, and at the rated load of the wind power plant, i.e. at the rated rotational speed and with a generator torque greater than zero.

While a light sheet is generated at a designated region, images of fluid flowing through the designated region are formed at different times. For an inspection region of the plurality of inspection regions defined in the images that has a degree of difference exceeding a threshold between the local flow velocity vector v(a, b, T) at a certain time T and a reference flow velocity vector v(a, b, T.sub.±) at times T.sub.± that are different from the certain time T, the flow velocity vector v(a, b, T) at the reference time T is corrected with the reference flow velocity vector v(a, b, T.sub.±).

A vehicle position detecting device according to an embodiment includes a wheel speed acquisition unit, a skid detection unit, a vehicle body speed calculation unit, and a position calculation unit. The wheel speed acquisition unit acquires a wheel speed of a wheel of a vehicle corresponding to rotation of the wheel. The skid detection unit detects a skid of the wheel. The vehicle body speed calculation unit calculates, when the skid is not detected by the skid detection unit, a vehicle body speed corresponding to the speed of a vehicle body of the vehicle based on the wheel speed acquired by the wheel speed acquisition unit, and corrects, in response to detection of the skid by the skid detection unit, the wheel speed acquired by the wheel speed acquisition unit based on correction information and calculates the vehicle body speed based on the corrected wheel speed. The position calculation unit calculates the position of the vehicle based on the vehicle body speed calculated by the vehicle body speed calculation unit depending on the presence of the skid.

A device protecting an aircraft turbomachine computer against speed measurement errors, including: on a speed regulation channel: a speed sensor of a turbomachine gearbox shaft, a speed measurement circuit, and a speed regulation circuit; on a monitoring channel: a speed sensor of a turbomachine gas generator shaft, a speed measurement circuit, and a turbomachine stop control circuit. Each channel uses dissimilar characteristics eliminating common mode errors. Each speed sensor delivers a pseudo-sine frequency signal. On each channel, speed monitoring circuits compare the frequency signal with a minimum threshold, delivering an error signal when the measured frequency is lower than the minimum threshold. A common speed cross checking circuit detects exceeding a determined deviation between both frequencies, the monitored deviation being higher or lower than a maximum deviation corresponding to loss of a frequency period on either sensor. Analyzing the error signals, exceeding the determined deviation can control stopping the turbomachine.

A device protecting an aircraft turbomachine computer against speed measurement errors, including: on a speed regulation channel: a speed sensor of a turbomachine gearbox shaft, a speed measurement circuit, and a speed regulation circuit; on a monitoring channel: a speed sensor of a turbomachine gas generator shaft, a speed measurement circuit, and a turbomachine stop control circuit. Each channel uses dissimilar characteristics eliminating common mode errors. Each speed sensor delivers a pseudo-sine frequency signal. On each channel, speed monitoring circuits compare the frequency signal with a minimum threshold, delivering an error signal when the measured frequency is lower than the minimum threshold. A common speed cross checking circuit detects exceeding a determined deviation between both frequencies, the monitored deviation being higher or lower than a maximum deviation corresponding to loss of a frequency period on either sensor. Analyzing the error signals, exceeding the determined deviation can control stopping the turbomachine.

Methods for calibrating an emission rate measurement of a gas are provided. The methods involve discharging a reference gas that is the same or a different composition than a subject gas. If the same or similar, then a combined emission rate of the reference and subject gas is measured, as well as an emission rate of the subject gas only. A deviation, or an one or more adjusted parameter, of the combined and subject gas measurement from the reference gas discharge rate is used to calibrate the subject gas measurement. If the reference gas is different, the emission rates of the subject and reference gas are measured, and a deviation, or an one or more adjusted parameter, of the measured rate from the discharge rate of the reference gas is used in calibrating the subject gas measurement. The methods may also use a modified 2-D tracer measurement as a reference.