Abstract: Relative compression in an asymmetric internal combustion (IC) engine is determined by measuring the change in speed of the engine crankshaft while the engine is cranked without ignition during each cylinder sub-cycle; the actual change in speed from a maximum to a minimum is measured during the compression stroke of each cylinder of the cylinder bank which is first to fire in the alternating left bank/right bank firing order of the engine, and the change in speed from a minimum to a maximum is measured during the expansion stroke of each cylinder of the second bank, such that the changes in engine speed over one engine cycle is provided as a sequence of delta speed signals associated alternately with a compression stroke and next with an expansion stroke for succeeding left bank and right bank cylinder displacements in accordance with the firing order; the delta speed signal magnitude associated with each cylinder, i.e.

Abstract: A color calibration procedure for use with a color raster scanner includes the steps of: identifying small areas on the source chart, or medium to be scanned, which contain only one color and assigning a color number to each area; positioning the scan head of the color raster scanner at two locations within the area identified and establishing the coordinate values for each of these two areas so as to bound by the coordinate definition the corners of a rectangular portion within the identified area; recording at each of a plurality of samples between the defined coordinates in each area the color samples resident therein; comparing the color samples of each color number obtained from each area with the samples obtained for each other color number of the other areas to determine the percentage of interference between colors and identifying the number of color samples which interfere with two or more colors as uncalibrated samples; and modifying the limits for a selected one of the spectral parameters associate

Abstract: A universal analog signal interface includes a pair of signal conditioning circuits, each responsive to one of a pair of analog signals presented between two inputs of each for providing corresponding pairs of output signal manifestations representative of the magnitude and the phase of the pair of signals received; the analog interface further including signal conversion circuitry responsive to each of the pairs of signal manifestations of magnitude and phase for providing a digital signal representative of the ratio of the smaller magnitude signal manifestation divided by the larger magnitude signal manifestation and for providing digital signals representative of each of the phase signal manifestations.

Abstract: An RTD probe interface having a three-wire interconnection with a source excitation line, a source return line, and a sensed signal line, includes: an excitation signal source connected between the source excitation line and the source return line for providing an excitation current signal through the RTD; an amplifier having first and second signal inputs connected respectively to the source excitation line and the sensed signal line, for providing an output voltage signal at a magnitude proportional to the difference magnitude between the voltage signals present at the first and second amplifier inputs, and a bias signal source connected between the sensed signal line and the source return line for presenting a bias current signal to the sensed line, at a magnitude and phase equal to that of the excitation current signal, for providing equal line impedance dependent values in the voltage signals appearing at the first and second inputs of the amplifier.

Abstract: A color identification circuit for use in identifying color samples received by a color raster scanner from a multicolor cartographic source chart includes a plurality of color limit comparators, one for each spectral parameter data channel of the sampled color element, each limit comparator including for each resident color on the source chart, the range of spectral values for the spectral parameter associated therewith, the range of values for each parameter representing the variations in the same color as obtained through color measurement samples taken from the source chart prior to actual data raster scanning; the output identification of a defined color spectral parameter from each limit comparator being presented to a color encoder, the color encoder identifying a unique color in dependence on the spectral parameter identification signals from each of the color limit comparators.

Abstract: An angular rate sensor includes an improved impulse pump structure for providing fluid under pressure to a nozzle disposed at one end of a jet chamber to form a constant flow fluid jet, the jet chamber including a pair of temperature sensitive elements disposed at the other end in such a manner as to be differentially cooled by the fluid jet in dependence on the angular rotation of the sensor.

Abstract: The exhaust back-pressure of an internal combustion (IC) engine is used to provide an indication of the relative combustion efficiency of the engine's cylinders. The instantaneous values of back-pressure are sensed at selected, sub-cyclic crankshaft angular intervals, within a full engine cycle, each angle interval being substantially less than that associated with a cylinder sub-cycle, each sensed value of back-pressure being identified by the sensed angle position to provide an indication of the sub-cyclic fluctuation in back-pressure as they occur at known cylinder exhaust stroke cycles within the engine cycle, thereby providing identification of each sub-cyclic back-pressure pulse as being associated with a particular engine cylinder, the relative magnitudes of the back-pressure pulses being compared with each other to provide indices of the relative combustion efficiency of each cylinder.

Abstract: Measurement of the operation of the accelerator pump of an internal combustion (IC) engine is provided while the engine is running under load by snapping the engine throttle from a steady state throttle position to a full throttle position and back within a time interval less than the response time of the engine power valve (enrichment valve), and comparing the relative magnitudes of the carbon monoxide (CO) and hydrocarbon (HC) constituents of the engine exhaust gas measured before and after the snap acceleration to provide an indication of the performance of the accelerator pump.

Abstract: The relative power contribution of each cylinder in an internal combustion (IC) engine which is connected through a common drive shaft to an engine load and which is running at a selected speed, is provided as the relative magnitudes of each cylinder's contribution to the fluctuations in a sub-cyclic net torque signal provided as the difference torque value between an instantaneous sub-cyclic engine torque signal and an instantaneous sub-cyclic load torque signal.

Abstract: A color raster scanner includes separate optical paths including a resolution aperture for resolution imaging and a separate, larger screen aperture for large area imaging; each aperture receiving the reflected source chart image through common collection optics including a combination objective lens and collimating optics which extend the optical length to provide increased gain magnification of the sensed image into the objective image plane; the image from the collection optics being presented by relay optics which divide the image into the two separate apertures, at different gain magnification values (field stop to provide the resolution aperture with the major portion of the available light flux, the larger diameter value of the screen aperture allowing it to receive the minor portion of the available flux at a relatively consistent spectral intensity.

Abstract: A run-length encoder circuit for use in compacting data samples from a multicolor cartographic source chart includes hardware filtering which counts the number of incoming identical color samples and rejects them as noise unless they exceed a programmable count; the actual count value being dependent simultaneously on the number of incoming color samples and also the particular type of color, either a line color or an area color which was recognized as valid.

Abstract: A DITS receiver provides direct memory access (DMA) for a central processing unit (CPU) to the latest update value of a plurality of pre-identified signal data words stored in a DITS data RAM. The DITS stores the data received asynchronously on a plurality of input channels directly in RAM as it is received, by stripping the first byte of the data word information field which identifies the data source and using this first byte ID as an address pointer to define the location in RAM for each remaining signal bit of the data word. The DITS slices the data received on each input channel into samples of less than one bit cell duration through a common sampling network which under sequence control provides commutation of the input channel samples to ensure that dual speed input channel are each sampled at least one time within the signal speed time period. The sampled data is multiplexed into a serial data stream and steered either to a first byte address register or directly to the data RAM.

Abstract: An angular rate sensor includes a unitary structure impulse pump for providing fluid under pressure, at a constant rate of flow, to a nozzle disposed at one end of a jet chamber to form a constant flow fluid jet, the jet chamber including a pair of temperature sensitive elements disposed at the other end in such a manner as to be differentially cooled by the fluid jet in dependence on the angular rotation of the sensor.

Abstract: The instantaneous values of intake manifold vacuum in an internal combustion (IC) engine running under load are measured to provide an indication of the relative performance and relative suction ability of each cylinder in the engine. The instantaneous values of manifold vacuum are sensed at selected, sub-cyclic crankshaft angle intervals within a full engine cycle, each angle interval being substantial less than that associated with a cylinder sub-cycle, each sensed value of manifold vacuum being identified by the sensed angle position to provide an indication of the sub-cyclic fluctuations in manifold vacuum as they occur at known cylinder intake strokes within the engine cycle, thereby providing identification of each sub-cyclic fluctuation in manifold vacuum as being associated with a particular cylinder, the relative magnitudes of the manifold vacuum fluctuations providing a relative indication of each cylinder's performance and suction ability within a common engine cycle.

Abstract: The spark voltage waveform at the secondary of the ignition coil of an internal combustion (IC) engine is sensed over a plurality of successive engine cycles. The instantaneous sub-cyclic position of the engine crankshaft is measured at successive crankshaft angle increments within each engine cycle and each sensed spark voltage signal is identified by the instantaneous value of crankshaft position at which it appears, thereby providing identification of each spark voltage signal with an associated cylinder of the engine. The number of samples for each cylinder together with the peak KV voltage magnitude and time duration of each are measured and the maximum, minimum and mean values of peak KV and spark duration for the spark signals associated with each cylinder together with the number of samples obtained are compared with the values obtained for each other cylinder to provide an indication of the relative sub-cyclic ignition efficiency of the ignition secondary circuit and the individual cylinders.

Abstract: A life tracking system (LTS) provides a life history recording for each module of a gas turbine engine, including module type and serial number together with total use, or operating time for each module. The total use may include total actual operating hours, total operating time under known high stress conditions, a weighted total time reflecting operational parameters, or any combination of these use indicators. The module information is stored as a permanent record with the module identification (ID) in a read/write non-volatile memory which may be read by a ground based data system. As such, each engine module may be tracked, automatically, from manufacture through its total life cycle in each engine configuration and/or aircraft in which it is used, without the necessity of human recording.

Abstract: A high resolution optical position sensor for measuring the linear displacement of a reciprocating device with a long stroke, includes a code plate having a substrate comprised of a fiber optic faceplate having a plurality of parallel optical waveguides which are fused together and aligned perpendicular to each of two major surfaces of the faceplate, and an optical mask with serial transparent and opaque regions encoded in each of a plurality of bit channels disposed on one of the two major surfaces of the faceplate, a portion of the plurality of optical waveguides being in registration with the transparent regions of each bit channel.

Abstract: A terminal reheat HVAC system which regulates the temperature in a plurality of temperature controlled spaces by modulating the temperature of cool discharge air presented to each of the spaces from an air handler source, each space receiving the cool discharge air through an associated space distribution unit which includes heating apparatus supplied from a common heat source for reheating the cool air to provide temperature regulation within the space in response to a space temperature error signal from an associated space temperature control, is controlled by electronic processing means in combination with dedicated sensing and control apparatus which provide actuation of the air handler and common heat source only in response to actual sensed space temperatures outside of a temperature band established by heat and cool temperature reference signals stored in the electronic processing means, the electronic processing means further providing modulation of the cool discharge air temperature from the air hand

Abstract: The RMS voltage of the output sine wave of a power inverter is regulated by pulse width modulation (PWM) of the rectangular waveform fundamental signal of the inverter bridge with a single sliding notch in each half cycle of the rectangular wave, each notch having a pulse width and position in the wave which is dependent on the required attenuation of the RMS value, and which may be varied, in a continuous manner, between a variable pulse width edge notch, a fixed pulse width notch which slides from an edge notch to a center notch position, and a variable pulse width center notch.

Abstract: A line protocol format with a low bit overhead provides for the high accuracy, asynchronous exchange of digital signal information between processing units in a supervisory control system having a central processing unit (CPU) and at least one remote processing unit (RPU).