Abstract: A processor of a signal processing circuit for calibrating an electro-capacitance pressure sensor includes a coefficient arithmetic section for calculating calibration value and a calibration arithmetic section. The calibration arithmetic section calculates an electro-capacitance ratio between electro-capacitance C1 and C2 detected by an electro-capacitance pressure sensor and conducts a calibration calculation from the electro-capacitance ratio to output a converted pressure value. The processor includes a fundamental arithmetic section for conducting a calculation given by f=(Z−W)/(X−Y) for predetermined arguments X, Y, Z and W input by the coefficient arithmetic section or the calibration arithmetic section and for outputting the calculation result f to the one of the coefficient arithmetic section and the calibration arithmetic section providing the input. The fundamental arithmetic section provides shared calculating for the coefficient calculation and calibration calculation.

Abstract: A self-calibrating sensor includes a sensor element for electrically detecting change in physical amount of a workpiece. A signal output device detects changes of the sensor element to output an electric signal. A processor conducts calibration calculation for the electric signal to adjust to the physical amount of the workpiece. A memory stores calculation results of the processor. The processor includes a calibration value calculating circuit for calculating a calibration value by conducting the calibration calculation based on a predetermined transforming formula and a calibration completion determining circuit for determining whether calculation of the calibration value by the calibration value calculating circuit is completed or not. The presence of the calibration value calculating circuit and the calibration completion determining circuit eliminates the need for connecting to an outside computer through an exclusive line for calculating the calibration value.

Abstract: A tire air-pressure abnormality alarming device for informing decrease in air-pressure of tires attached to a four-wheeled vehicle, characterized in that the device prohibits start of initializing operations for updating stored values for physical amounts related to tires or wheels in the case where air-pressures of the tires are judged to be normal, if air-pressure abnormality of a tire is being alarmed. Initialization is accepted only after the internal pressure has become normal, whereby erroneous initialization with any tire being in a decompressed condition can be prevented. Thus, normal operations for detecting decompression of a tire can be maintained.

Abstract: A method of correcting drift in a sensor includes the step of identifying a calibration command. A nominal zero pressure sensor drift correction factor for the sensor is identified by relying upon a calibration voltage value and a calibration temperature value secured at a nominal zero pressure condition. Sensor output is subsequently adjusted according to the nominal zero pressure sensor drift correction factor.

Abstract: A method by which an operation characteristic of a proportional electromagnetic control valve can be automatically measured in a short period of time. For this purpose, in the operation characteristic measuring method of the present invention, when the proportional electromagnetic control valve to be measured is a proportional electromagnetic pressure control valve, at each step for measuring a pressure of a hydraulic circuit, the pressure is measured with a predetermined interval of time, the pressure is assumed to be stabilized at a point of time when a difference &Dgr;P between the measured pressure value and the previously measured pressure value becomes a predeterminied level or less, and the measured pressure value at this point of time is employed as a pressure corresponding to a load current at this step.

Abstract: A system for sensing the value of a physical property (such as force, temperature or movement) and having a plurality of sensors used in combination, for example a weighing system where a plurality of load cells are employed to sense the magnitude of a load placed on a weighing platform, has a first analogue to digital (A/D) converter and a second A/D converter, capable of faster operation than said first A/D converter; wherein said first A/D converter produces a signal representative of the average of the physical property and said second A/D converter produces a signal representative of the distribution of sensor output signal amplitudes amongst the sensors, thereby overcoming the problems associated with the prior art in producing a high resolution, high accuracy result but without requiring a high speed, high resolution A/D converter.

Abstract: An onboard system for use in measuring, computing and displaying the weight and center-of-gravity for aircraft, while keeping aircraft movement to a minimum. Pressure sensors are mounted in relation to each of the landing gear struts. An onboard pump and reservoirs are attached to each of the landing gear struts and are activated by a computer/controller, while landing gear strut pressures are monitored in the determination of strut stiction. The computer/controller calculates the stiction of each landing gear strut and compensates for the pressure distortions caused by landing gear strut stiction. Additional features include reducing strut stiction, measuring landing gear strut fluid levels, monitoring landing gear strut health, weight adjustments for external ice and de-icing fluids, weight adjustments for wind, monitoring aircraft landing gear strut movement.

Abstract: A sensor system includes a first sensor for sensing a parameter in a first sensing range and providing a first sensor signal indicative of the parameter. A second sensor senses the parameter in a second sensing range and provides a second sensor signal indicative of the parameter. The second sensing range is larger than the first sensing range and the first and second sensing ranges overlap in a transition overlap region. A sensor output device provides a sensor output signal based on the first and second sensor signals by blending components of the first and second sensor signals according to a blending function such that the sensor output signal is single valued, has no induced hysteresis and is continuously differentiable.

Abstract: The static pressure within an air-supported structure is monitored and controlled in accordance with monitored environmental conditions. The static pressure is kept at the minimum value required to maintain the structures's integrity, thereby using a minimum amount of energy. As outside wind velocity incrementally increases, the static pressure is increased incrementally. Under certain weather conditions such as high winds and frozen precipitation, the static pressure is increased to a maximum limit. As a safety feature, a secondary inflation device is activated to assist a primary inflation device to quickly increase pressure in the structure in response to a sudden loss in pressure.

Abstract: Data processing system for calculating the flowrate of air from a pressurized reservoir to an air pressure communication line. A pressure sensor is connected to the reservoir to provide an analog signal indicating pressure, which is converted into a digital pressure signal. The system also has a sensor connected to pressure ports upstream and downstream of an orifice, located between the reservoir and the air pressure communication line. This provides an analog differential pressure signal which is converted into a digital differential pressure signal, which is processed to obtain a first digital flowrate signal. This is combined with the digital pressure signal to obtain a flowrate correction value, from which a revised flowrate value is obtained. This revised flowrate value may be sent to an operator of the system, to a control system, or to an alarm system.

Abstract: An air data measurement system includes a device for sensing air pressure outside an aircraft, a pressure transducer in fluid communication with the air pressure sensing device and having a piezoresistive bridge attached on a flexible diaphragm. The piezoresistive bridge has an electrical resistance which varies in response to the sensed air pressure applied to the diaphragm and whose sensitivity varies with the magnitude of the excitation current passing therethrough. The system also includes a current supply operatively connected to the pressure transducer for supplying and varying the magnitude of the excitation current to the piezoresistive bridge. Further included is an output device connected to the pressure transducer for sensing a change in the electrical resistance of the piezoresistive bridge and outputting a signal from the piezoresistive bridge corresponding to the sensed air pressure.

Abstract: An apparatus for detecting the drop in air pressure of any of tires mounted on a vehicle. The device finds, in finding an initial correction factor for eliminating the effect of a difference in effective rolling radius depending on an initial difference among the tires on the rotational angular velocities of the tires, the ratio of the rotational angular velocities of a predetermined pair of the tires as an initial correction factor, averaging and updating the initial correction factor for each sampling period, and taking the initial correction factor found when the number of times of the updation reaches a predetermined number of times as the final initial correction factor. When it is judged that the air pressure of any of the tires drops before the final initial correction factor is found, the calculation of the initial correction factor is stopped.

Abstract: A modified air activated pressure valve is described, together with a method for its manufacture, that has a pressure sensitive switch located in the inlet chamber and in the outlet chamber. These pressure sensitive switches are preset by the user to output a finite voltage (typically about 5 volts) only when they are exposed to a pressure that exceeeds some value. The outputs of both switches may then be displayed, as needed. Additionally, a display circuit is provided that gives an output signal only when both the inlet and the outlet chambers are at or above their intended pressures.

Abstract: A controller comprised of a high speed central processing unit, at least about 32 analog input channels operatively connected to the central processing unit, at least about 48 digital input channels operatively connected to the central processing unit, at least about 32 digital output channels operatively connected to the central processing unit, at least 20 control input channels connected to the central processing unit, and electroluminescent display means for displaying graphical information connected to the central processing unit.