Abstract: The present invention concerns a process and a circuit enabling determination of the last intermediate node of a pathway comprising a minimum number of nodes from the m-th node to the n-th node in a network comprising p nodes interconnected by a number of links (p being a positive whole number). The process includes steps of iterative matrix calculation and comparison of elements of the same rank of certain matrices, and is especially suitable for communications networks constituted by a number of geographically separated nodes connected to one another by communications lines.

Abstract: Method and apparatus are described for bringing a rotating body, set in rotation by a drive, to a standstill as the conclusion of a work cycle. The rotating body may be placed in bearings in a balancing machine where it is investigated for unbalance. Characteristic values for the drive and the rotating body obtained during the acceleration phase are utilized in conjuction with one another for purposes of stopping the rotating body at an exact and specific position for machining purposes at that position on the surface of the rotating body.

Abstract: An automatic position coordinate determining device comprises a data tablet which has a single magnetostrictive element in which strain waves are induced for determining the position coordinates of a pointer relative to a pair of mutually orthogonal coordinate axes obliquely disposed with respect to the magnetostrictive element. Two mutually orthogonal pluralities of parallel equidistantly spaced electrical conductors form a grid network on the top surface of the tablet. These pluralities of conductors are wrapped around the edge of the tablet and spatially compressed to form respective X and Y conductor grids over opposing quadrants of the tablet bottom surface. A movable pointer travels along the top surface of the tablet while the magnetostrictive element is arranged along the diagonal of the tablet bottom surface. The conductors of the X and Y grids are inductively coupled to the diagonal magnetostrictive element.

Abstract: Apparatus for determining the life usage of components subject to variable operating conditions particularly helicopter gears subject to variable torque. A monitor 10 provides an analogue signal of the level of operating parameter which is passed through conditioning means 26 including pre-amplifier 29, filter stage 31, multiplexer 38 and analogue to digital converter 40. A memory 42 stores life usage data for the component and a microprocessor 43 repeatedly samples the monitored level of the parameter and determines the life usage in successive time intervals. Electromechanical counter 53 provides a cumulative output of the life usage of the components. The microprocessor 43 also analyses the parameter levels into ranges or bands and the total time each component is operating in each range is stored and printed out.

Abstract: A universal fuel quantity indicator apparatus (100,102) includes a digital fuel quantity indicator (100) having an internal microprocessor control unit (104) and a removably connectable digital calibration trim unit interface (102) which enables the fuel quantity indicator (100) to be reconfigured for different fuel tanks by varying selectable fuel tank parameters, such as constants associated with a fuel quantity determination based on calculations of capacitance of a tank capacitor array (110) and a compensator capacitor (112).

Abstract: A digital frequency locked loop is disclosed for use with programmable signal processing apparatus wherein frequency locking is desired from staggered data samples. Sampling means are provided for sampling an input signal, at instants determined by the sampling signal, to provide N data signals from M cycles of the input signal wherein each data signal represents the magnitude of the input signal at the sampling instant. Signal processing means are provided for performing a unique approximation to the optimal mean square estimation analysis to provide a frequency deviation signal which is proportional to the difference in frequency between the sampling and input signals. The frequency deviation signal is used to modulate the period of the sampling signal such that the frequency of the sampling signal is maintained in constant proportion to the frequency of the input signal.

Abstract: Apparatus and method for determining transient temperature and stress distributions in turbomachines and system components as a function of operating conditions where direct measurements on the rotating components are prevented. The apparatus includes a microprocessor which computes temperature and stress distributions in real time for components of complex shapes. The apparatus employs a memory containing a set of standard temperature distributions under particular operating conditions and the temperature stresses in the component are estimated on the basis of the closest temperature distributions in the set. The apparatus can be embodied as an on-board in-flight LCF monitor of aircraft engine rotors or as an LCF monitor of a turbomachine for power generation such as a stationary turbine generating unit.

Abstract: In an electron beam system in which the beam is exposed in selected prescribed patterns on a target surface, stored pattern data specifies the location of the pattern as coordinates on the target plane of a reference point in the pattern, specifies the shape of the pattern as a code identifying one of several permissible shapes, and specifies the size of the pattern as dimensions of first and second pattern dimensions in the target plane. In exposing each pattern, the data is: modified to provide the selected pattern in the desired size; modified to determine the maximum beam size for the selected pattern; dynamically fragmented into individual beam flashes; and examined to determine the beam spot size, shape and position for each flash. All patterns are generally designated as trapezoids, with a triangle considered as a trapezoid having one side of zero length, a rectangle considered as a trapezoid having four right angles, etc.

Abstract: Method and apparatus are disclosed for providing a sampling signal having a frequency which is maintained in constant proportion to the frequency of an input signal. The input signal is sampled at instants determined by the sampling signal to provide a plurality of data signals associated with one cycle of the input signal. A signal processor is adapted to receive first and second pluralities of data signals associated with first and second cycles of the input signal and to perform two discrete Fourier analyses to provide two phasor signals representing two voltage phasors of respective fundamental frequencies of the discrete Fourier transforms. The phasor signals are used to generate a difference signal indicative of the angle between the two voltage phasors and, therefore, proportional to the difference between the sampling frequency and the input frequency.

Abstract: In a system for generating a vector representation of a waveform on a cathode ray tube screen, the minimum and maximum magnitudes of an analog waveform acquired during each of successive measurement periods are stored in a random access memory, with the minimum and maximum signal values for each measurement period being stored in arbitrary order. The minimum and maximum signal values within each measurement period are then time sequenced by selectively comparing the minimum and maximum values obtained during each such measurement period with the values obtained during preceding and/or succeeding periods. Also according to these selected maximum and minimum comparisons, the maximums obtained during selected measurement periods are decremented by a selected amount while minimums obtained during selected periods are incremented by a selected amount.

Abstract: An aerosol generating system for maintaining a constant concentration of aerosol in a chamber is disclosed. The system includes an aerosol generator in a closed chamber. A small fan in the chamber distributes the aerosol within the chamber. A particle analyzer connected to the chamber draws aerosol samples and analyses samples to monitor at least one characteristic property of the aerosol. Typically, these are particulate concentration and particulate size. The system includes a control responsive to signals from the analyzer representing changes in the monitored characteristic property to control operation of the aerosol generator. The control is such as to maintain the characteristic property substantially constant. The system may also be equipped with humidity and temperature control elements for maintaining these factors constant within the chamber.

Abstract: A filter test device comprises an inlet which communicates with a gas source, an outlet which communicates with the inlet of a filter vessel, a pneumatic valve apparatus disposed between the inlet and the outlet of the filter test device for regulating the flow of gas from the source to the filter vessel, an electronic controller for controlling the pneumatic valve apparatus in accordance with one of a plurality of sets of parameters and including a memory circuit for storing all of the sets of parameters, and a mechanism for selecting one set of parameters from all the sets of parameters stored in the memory circuit.

Abstract: Fractals are generated based on their self-similarity properties. This is done by convolving a basic shape, or "generator pattern", with a "seed pattern" of dots, in each of different spatial scalings. The convolution results are then combined to define a multi-dimensional object, identifiable as a fractal. Two-dimensional sections of this object are used in generating graphic images for video display.

Abstract: A device for indicating a physical quantity such as depth in water by means of a pointer moving around a numbered face, using a C-MOS type computer for sampling the physical quantity at regular intervals and calculating the increment between the preceding value and the last value of the physical quantity. A pulse motor drives the pointer as many steps as are required for reaching the position at which the pointer indicates the last value of the physical quantity. The use of a sampling system and a pulse motor renders the device small enough so that it can be incorporated in a wrist watch.

Abstract: An adaptive control system regulates operation of a mechanical seal assembly by reacting dynamically to changes in seal operating conditions to provide minimal wear with minimal fluid leakage. The disclosed "self-learning" method adapts automatically to arbitrary changes in fluid medium temperature and pressure, as well as shaft rotation speed, by detecting a limit cycle type oscillation of a seal-related variable, such as temperature of a seal face and/or fluid temperature. This variable is monitored via a microcomputer-based system which identifies these abrupt oscillations or spikes. The control algorithm selects a particular displacement of an actuator to modify the seal face deflection to the optimal value, and in this way attains maximum seal life while minimizing leakage.