Abstract: A method and apparatus for measuring circumferential characteristics of train wheels for potential indication of train wheel wear that includes at least one microwave transceiver disposed adjacent to a section of train track and oriented to transmit microwave energy toward and receive microwave energy reflected from a radially oriented surface of a train wheel that traverses the track section. Wheels are rolled along the track section in sequence while the transceiver is energized so as to transmit energy toward the wheel and develop a varying interference pattern of peaks (alternating minima and maxima) caused by reflection from the radially oriented surface of the wheel. The transceiver provides an electrical signal that varies as a function of such interference pattern, and one or more desired radial characteristics of the wheel are determined as a function of such signal.

Abstract: A system and method for monitoring position of a piston within a fluid-actuated cylinder by radiating microwave energy into the actuator cylinder and measuring axial position of the piston as a function of microwave resonances and the frequencies at which such resonances occur. Separate microwave transmitting and receiving antenna probes are mounted on one end cap of the actuator cylinder, which has a fixed diameter and an axial dimension which varies as a function of piston position. The transmitting probe is coupled to an oscillator which is controlled to sweep a predetermined frequency range for generating one or more TM.sub.01q resonant modes within the cylinder cavity. A threshold detector and a peak detector are coupled to the receiving probe for detecting occurrence of cavity resonances. Latches store oscillator control signals associated with occurrence of up to eight such resonance events, with the stored control signals thus being an indication of resonant frequencies.

Abstract: A method and apparatus for measuring compression ratio and/or clearance volume in an internal combustion engine cylinder wherein the crankshaft angle associated with piston top dead center position is obtained and cylinder pressure is measured at a number of incrementally spaced piston positions. Changes in cylinder volume between the incrementally spaced piston positions are determined from nominal engine design parameters. These multiple pressure and volume figures are then employed in a programmed microprocessor to determine the constants .gamma. and k in the polytropic equation for relating cylinder pressure to volume PV.sup..gamma. =k. Clearance volume V.sub.TDC is determined using the constants .gamma. and k, and measured pressure at TDC or incremental volume figures. Compression ratio is determined by the fraction (V.sub.DP +V.sub.TDC)/V.sub.TDC, where V.sub.DP is total piston displacement volume obtained from nominal engine design parameters.

Abstract: A method and apparatus for measuring compression ratio and/or clearance volume in an internal combustion engine cylinder wherein the crankshaft angle associated with piston top dead center position is obtained and cylinder pressure is measured at a number of incrementally spaced piston positions, including the TDC position. Changes in cylinder volume between the incrementally spaced piston positions are determined from nominal engine design parameters. These multiple pressure and volume figures are then employed in a programmed microprocessor to determine the constants .gamma. and k in the polytropic equation for relating cylinder pressure to volume PV.sup..gamma. =k. Clearance volume V.sub.TDC is then determined using the constants .gamma. and k and the measured pressure at TDC. Compression ratio is then determined by the fraction (V.sub.DP +V.sub.TDC)/V.sub.TDC, where V.sub.DP is total piston displacement volume obtained from nominal engine design parameters.

Abstract: An engine ignition timing control system and method wherein a timing module associated with a given engine includes a read only memory and circuitry for generating information related to engine crankshaft rotation. The module memory is programmed with information relating piston position to crankshaft rotation. The crankshaft rotation and piston position information is made available to an on-board ignition computer for precise control of ignition angle. Also disclosed are a system and method for separately programming the module memory associated with each engine as a function of the piston mechanics of that engine.