Abstract: An example apparatus includes a controller configured to control operation of a salient-type, multiphase motor in accordance with a technique including periodic on and off-times, the motor including a stator and a rotor. The controller is configured to calculate or receive values representing changes in current to the motor during the respective on and off-times or measurements proportional thereto, and calculate an inductance of the motor as a function of the values and a supply voltage to the motor. And the controller is configured to determine a position of the rotor based on the inductance of the motor, and control operation of the motor based on the position of the rotor.

Abstract: An example method includes receiving output voltage data from an array of at least four thermopiles placed around the circumference of a projectile such that for any rotation of the projectile during flight thereof, at least a pair of the thermopile having upwardly-facing fields of view referenced to the earth-fixed coordinate system. The method includes determining the pair of upwardly-facing thermopiles based on the output voltage data from the array, with the respective pair of thermopiles including a thermopile p and next adjacent thermopile p+1. The method includes determining a ratio of the output voltage data from thermopiles p and p+1, and applying the ratio to a function associating, for any pair of thermopiles n and n+1, a ratio of output voltage data from thermopiles n and n+1, and a roll angle ?n of thermopile n referenced to the earth-fixed coordinate system.

Abstract: An example method includes receiving output voltage data from an array of at least four thermopiles placed around the circumference of a projectile such that for any rotation of the projectile during flight thereof, at least a pair of the thermopile having upwardly-facing fields of view referenced to the earth-fixed coordinate system. The method includes determining the pair of upwardly-facing thermopiles based on the output voltage data from the array, with the respective pair of thermopiles including a thermopile p and next adjacent thermopile p+1. The method includes determining a ratio of the output voltage data from thermopiles p and p+1, and applying the ratio to a function associating, for any pair of thermopiles n and n+1, a ratio of output voltage data from thermopiles n and n+1, and a roll angle ?n of thermopile n referenced to the earth-fixed coordinate system.

Abstract: An example apparatus includes a controller configured to control operation of a salient-type, multiphase motor in accordance with a technique including periodic on and off-times, the motor including a stator and a rotor. The controller is configured to calculate or receive values representing changes in current to the motor during the respective on and off-times or measurements proportional thereto, and calculate an inductance of the motor as a function of the values and a supply voltage to the motor. And the controller is configured to determine a position of the rotor based on the inductance of the motor, and control operation of the motor based on the position of the rotor.

Abstract: An aircraft ultrasonic system for fuel gauging and battle damage detection comprises: at least one ultrasonic transducer disposed at a fuel tank of the aircraft; a first circuit for exciting the at least one ultrasonic transducer to transmit an acoustic pulse toward a surface of fuel in the tank, the at least one ultrasonic transducer operative to receive acoustic echo pulses reflected from the fuel surface and convert the acoustic echo pulses to electrical echo pulses, the at least one ultrasonic transducer also operative to receive acoustic compression wavefront pulses impinging thereon and convert the acoustic compression wavefront pulses to electrical compression wavefront pulses; and a second circuit for receiving and processing the electrical echo and compression wavefront pulses from the at least one ultrasonic transducer, the second circuit operative to perform fuel quantity measurements using the electrical echo pulses and to perform battle damage detection using the electrical compression wavefront

Abstract: A liquid measurement system including interface apparatus for sharing the excitation and signal processing of an ultrasonic transonic transducer and temperature measuring device remotely located at a liquid container is disclosed. The interface apparatus includes a common conduction path coupled to both of the ultrasonic transducer and the temperature device for conducting first excitation signals to the ultrasonic transducer and the corresponding echo signals therefrom, and for conducting second excitation signals to the temperature measuring device and the response signals therefrom, and an interface circuit for governing the conduction of the first and second excitation signals over the common conduction path from their generating sources and for providing a balanced interface for receiving both of the echo signals and response signals from the common conduction path.

Abstract: A method of detecting a dry/wet state of a dual thermistor bead sensor over a wide operating temperature range comprises the steps of: conducting first and second predetermined currents through one and another of the thermistor beads of the sensor, respectively, the second predetermined current being substantially less than the first predetermined current; measuring a first voltage across the one thermistor bead in response to the first predetermined current and generating a first signal representative thereof; measuring a second voltage across the other thermistor bead in response to the second predetermined current and generating a second signal representative thereof; modifying the second signal by an offset and gain to generate a third signal; and detecting the dry/wet state of the sensor over the wide operating temperature range based on the first and third signals.

Abstract: An ultrasonic transducer is disclosed comprising a layer of piezoresonator material capable of transmitting from a top surface thereof an ultrasonic pulse into a tank of liquid and receiving at the top surface reflections of the transmitted pulse from the liquid; and a matching layer of pure crystalline Boron Nitride disposed on the top surface. The pure crystalline Boron Nitride layer is operative to match the acoustic impedances of the piezoresonator material and the tank liquid about the operational frequency passband of the ultrasonic pulse. The ultrasonic transducer may be disposed in an assembly for measuring a quantity of liquid in the tank.

Abstract: A method of and apparatus for discriminating among ultrasonic echoes reflected from various objects in a tank containing liquid is disclosed. Ultrasonic signals are generated from an ultrasonic transducer into liquid contained in a tank. Ultrasonic echoes are received by the transducer from various objects in the tank including a surface of the liquid in response to the generated ultrasonic signal and are converted into electrical echo signals representative thereof. Data samples of the electrical echo signals are generated and processed by a signal processor using wavelet function processing to generate wavelet coefficients thereof in a wavelet domain. The wavelet coefficients of the echo data samples are used to discriminate the ultrasonic echoes reflected from the various objects in or part of the tank. In one embodiment, echoes reflected from the liquid surface are discriminated from echoes reflected from other objects based on the wavelet coefficients of the echo data samples of each.

Abstract: The present invention is directed to an improved method and apparatus for determining ultrasonically the quantity of liquid in a tank having multiple inventive aspects. One aspect includes an ultrasonic transducer having three layers, the top two each having a thickness of approximately one-quarter wavelength and having materials with corresponding acoustic impedances which together are chosen to match the acoustic impedance of the bottom layer to the acoustic impedance of the tank liquid about the operational frequency passband of the ultrasonic pulse transmitted from the transducer. Another aspect involves a system and method for discriminating between echo sources of an ultrasonic burst echo signal resulting from an incipient ultrasonic burst signal transmitted from the ultrasonic transducer.

Abstract: The present invention is directed to an improved method and apparatus for determining ultrasonically the quantity of liquid in a tank having multiple inventive aspects. One aspect includes an ultrasonic transducer having three layers, the top two each having a thickness of approximately one-quarter wavelength and having materials with corresponding acoustic impedances which together are chosen to match the acoustic impedance of the bottom layer to the acoustic impedance of the tank liquid about the operational frequency passband of the ultrasonic pulse transmitted from the transducer. Another aspect involves a system and method for discriminating between echo sources of an ultrasonic burst echo signal resulting from an incipient ultrasonic burst signal transmitted from the ultrasonic transducer.

Abstract: Liquid gauging system for liquid in a container includes a plurality of sensors; each of the sensors measuring a respective parameter of the liquid in the container and producing a sensor output related to its measured parameter; there being at least two sensors that measure different parameters of the liquid; and a processor that receives the sensor outputs and determines, based on the sensor outputs, a quantity of the liquid in the container; the processor determining the quantity by executing at least one sensor fusion algorithm that is based on a set of relationships between the measured parameters and the quantity. The gauging system can also include a data fusion process for determining quantity based on a plurality of quantity measurements.

Abstract: A universal sensor interface system that utilizes a common hardware and software interface to drive many types of sensors. A variety of stimulation signals are generated that are transmitted to a plurality of sensors. The stimulation signals cause the sensors to generate response signals in the form of parametric measurements, which are then converted into a common format. The sensor response signals are processed and output as usable inputs to a data consuming apparatus. A method of automatically determining the sensor configuration in an aircraft sensor system is also provided. During operation the host computer system or digital signal processor is programmed to analyze sensor response signals to detect sensor faults, help predict sensor failures, and determine if there has been a sensor error. The universal sensor interface system is also capable of notifying a system operator of wiring problems with a particular sensor or if a particular sensor is malfunctioning.