Showing papers on "Spark (mathematics) published in 1998"

An ion-sense engine fine-tuner

Abstract: The paper presents a real-time closed loop demonstration of spark advance control by interpretation of ionization current signals. Such control is shown to be able to handle variations in air humidity, which is a major factor influencing burn rates, and consequently pressure buildup and useful work transferred via piston to drive shaft. This leads to a clear improvement in engine efficiency compared to traditional systems using only engine speed and load. Inspired by the type of challenges and potential usefulness in interpretation of ionization current signals, the paper focuses on closed loop ignition control by ionization current interpretation. The topics discussed include: the basics of ionization currents; spark advance control, especially principles relating pressure information to efficiency; and the structure of the ion-sense spark advance controller. The experimental demonstrations and some conclusions are presented.

Engine management system

Abstract: An engine management system for 4-cycle engines includes a processing means and utilizes various inputs from sensors operatively connected to the engine for the purpose of providing the correct fuel/air ratio or spark ignition angle for the engine in a manner whereby the transient response is fast. The engine management system utilizes the rotational speed information that is obtained from a magneto or speed sensor to determine the speed of each engine revolution. The system effectively solves many of the fuel/air ratio problems that are caused by load transients occurring on the engine. By comparing such high pass filtered speeds of selected revolutions, the system is able to determine the inferred engine intake air flow. By using measured system rotational inertia compensation factors for the engine together with the inferred intake air flow, the system can accurately determine the amount of fuel to be fed to the engine for proper operation.

Individual cylinder idle spark control

Abstract: A method is provided for applying spark corrections calculated on an individual cylinder basis to the total spark advance for the motor vehicle engine to counter torque imbalances and stabilize crankshaft or engine accelerations. According to the invention, crankshaft feedback is used to measure an average acceleration of the crankshaft attributable to each cylinder. Thereafter, individual cylinder spark corrections designed to equalize the accelerations of each of the cylinders are calculated based on the individual cylinder average accelerations. The calculated individual cylinder spark corrections are then applied to the total spark advance. Preferably, an event delay is employed to correct for the phase lag caused by filtering the crankshaft accelerations which aligns the spark corrections with the proper cylinder.

Automated psychoacoustic based method for detecting borderline spark knock

Abstract: An automated method for detecting borderline spark knock in a spark ignition engine imitates borderline knock procedures in which human operators listen to engine sounds as a function of spark timing. The automated method employs a psychoacoustic model and a psychophysical process to estimate borderline spark knock. The psychoacoustic model represents the acoustic activity in the human auditory system in response to engine sounds. The psychoacoustic model is monitored as a function of spark timing to detect audible spark knocks. The psychophysical process alters the spark timing for detecting spark knocks until the spark timing converges to a value corresponding to borderline knock. The automated method eliminates human operator subjectivity in estimating borderline knock.

Method of manufacturing plastic film with pore-opening discharge spark control

Abstract: A method of producing plastics film ( 8 ) wherein high-voltage pulses are impressed between a pair of electrodes ( 4,6 ), thereby creating pores in a plastics film which is fed into the spark gap ( 5 ) between electrodes, characterised in that the number of discharge sparks which are generated subsequent to the pore-opening discharge spark is controlled by monitoring the pore-opening discharge spark and subsequent discharge sparks within one of the high-voltage pulses. The method produces fine pores having a uniform pore diameter under controlled circumstances.

Power measurements of spark discharge experiments.

Abstract: An accurate and precise knowledge of the amount of energy introduced into prebiotic discharge experiments is important to understand the relative roles of different energy sources in the synthesis of organic compounds in the primitive Earth's atmosphere and other planetary atmospheres. Two methods widely used to determine the power of spark discharges were evaluated, namely calorimetric and oscilloscopic, using a chemically inert gas. The power dissipated by the spark in argon at 500 Torr was determined to be 2.4 (+12%/_17%) J s_1 by calorimetry and 5.3 (± 15%) J s_1 by the oscilloscope. The difference between the two methods was attributed to (1) an incomplete conversion of the electric energy into heat, and (2) heat loss from the spark channel to the connecting cables through the electrodes. The latter contribution leads to an unwanted effect in the spark channel by lowering the spark product yields as the spark channel cools by mixing with surrounding air and by losing heat to the electrodes. Once the concentrations of the spark products have frozen at the freeze-out temperature, any additional loss of heat from the spark channel to the electrodes has no consequence in product yields. Therefore, neither methods accurately determines the net energy transferred to the system. With a lack of a quantitative knowledge of the amount of heat loss from the spark channel during the interval from ignition of the spark to when the freeze-out temperature is reached, it is recommended to derive the energy yields of the spark products from the mean value of the two methods with the uncertainty being their standard deviation. For the case of argon at 500 Torr, this would be 3.8 (±50%) J s_1.

Active adaptive EGR and spark advance control system

Abstract: The present invention provides a control system for the active adaptive control of exhaust gas recirculation and spark advance for an internal combustion engine automobile. While the automobile is operating, a control algorithm continuously receives data input from various sources such as the driving mode monitor, fuel consumption monitor, engine roughness monitor, and the engine knock monitor. Based on the data, the control algorithm then causes either an EGR command, a spark advance command, both an EGR and spark advance command, or no command at all to be generated so as to optimize the fuel economy of the automobile. This process is repeated until there is no further beneficial effect on fuel economy or engine roughness and/or engine knock is detected.

Sparks in MSGCs

Abstract: We have measured the spark rate as a function of voltages and geometric parameters and investigated the damage to Au, Al, Cr, W and Rh electrodes. Measurements of the spark signals compare well with simulations. We propose a new device, the Macro Gap Chamber.

Apparatus for diagnosing and controlling an ignition system of an internal combustion engine

Abstract: of EP0922856An apparatus for diagnosing and controlling an ignition system of an internal combustion engine includes an ignition coil controllable by an ignition control circuit, a spark voltage sensor electrically connected to the high tension side of the ignition coil secondary and an ion voltage sensor electrically connected to the low tension side of the ignition coil secondary. A computer processes the spark voltage signal by comparing the signal to a number of predefined spark voltage waveforms in memory. If the spark voltage signal matches any of the spark voltage waveforms in memory that correspond to a predefined ignition system failure mode, a corresponding error code is stored in memory. The computer is further operable to process a voltage peak of the spark voltage, wherein the voltage peak corresponds to the breakdown voltage in the spark gap of a spark plug connected to the secondary coil. If the voltage peak exceeds a peak threshold, or if a slope of the spark voltage waveform about the voltage peak is less than a slope threshold, the computer is operable to store a corresponding error code in memory. The computer is also operable to process the ion voltage signal to determine a combustion quality value and a roughness value therefrom. If the combustion quality factor is outside a predefined range or if the roughness value exceeds a roughness threshold, the computer is operable to adjust engine fueling, spark timing and/or spark energy.

An evaluation of spark mobility in electrical discharge machining

Abstract: Process instability and arcing failure in electrical discharge machining (EDM) are still serious problems in practice especially when high erosion rates are attempted. Most known solutions exhibit significant limit on material removal rate and do not always effectively eliminate the causes. This analysis addresses some basic mechanisms of instability and arcing which have been constantly overlooked. Spark mobility, an essential feature of any normal spark process, is proposed to characterize the inherent process resistance against spark concentration. The physical meaning of spark mobility is defined as the driving force that moves spark around in the electrode gap. It has been known, but taken for granted that the pulse sparks will keep moving in the electrode gap. The present investigation will that manifest spark mobility is highly process dependent, and not always available. From this point of view, the spark mobility is evaluated with the help of two proposed physical quantities: electrical field stress and dielectric breakdown strength. In this analysis, the difference in field stress is assessed by the stress factor, while the difference in breakdown strength is assessed by strength factor. The distributions of field stresses in a surface crater and around a surface hill are given by the solutions of a Laplace's equation in cylindrical coordinates. Both stress factor and strength factor are useful technical indexes with certain physical meaning. The differences in electrical field stress and dielectric breakdown strength are correlated with the tendency of spark movement, that is the spark mobility from a discharged spot to a new spot. Accordingly, the spark mobility is equal to the product of the stress factor and the strength factor. This systematic mechanism analysis will give exact answers to many "fuzzy" phenomena in EDM practice and resolve the complex contributions to process stability of some important parameters such as gap size and debris concentration.

Knock-sensing and spark-retarding circuit

Abstract: The vehicle (3) has an internal combustion engine (2) connected to a sensor (1), especially a knock sensor The knock sensor is connected to an electronic control circuit (4) This circuit is in turn connected to a spark advance and retard circuit (7) which retards the spark when knocking is detected The electronic control circuit consists of a measuring circuit (5) followed by a regulator circuit (6) which produces the signal that controls the spark advance and retard system The measuring circuit produces a reference signal which may be used to help diagnose a fault in the sensor circuit

Injector characteristics estimation for spark ignition engines

Abstract: Injector characteristics estimation is an essential ingredient for an effective automotive engine control system. An accurate estimation algorithm is presented in the paper. Simulation and experimental results are provided to demonstrate the quality of the algorithm.

Performance spark plug

Abstract: A spark plug includes a ground electrode and a center electrode. The ground electrode comprises a ring shaped member which is centered on the center electrode. A beveled ring shaped surface of the ring shaped member generally faces the center electrode. This increases the spark area of the ground electrode, providing for more consistent and stronger sparks, and even multiple sparks. A cross shaped channel is disposed centrally on a distal face of the center electrode. Because of the increased spark area which the channel provides, the spark is more likely to travel along the channel, rather than jump from point to point along the distal face of the center electrode, as can happen with conventional spark plugs; thus, the channel provides a stronger and more consistent spark.

Spark preventive device for refuse incineration furnace

Abstract: PROBLEM TO BE SOLVED: To collect sparks in an exhaust gas, which generate by a refuse incineration, as soot or dust without discharging them as they are from a flue. SOLUTION: In the spark preventive device, to a flue 7 of a trash incineration furnace 1, a smoke buffer cylinder 16 with a larger diameter than that of the flue 7, is connected, and at the center in the smoke buffer cylinder 16, a filter cylinder 20 made of a metal net, and a cover plate 22 which closes the upper surface of the filter cylinder 20, are provided under a hanging state, and the exhaust gas which is discharged from the flue 7, is passed in the filter cylinder 20 from the lower end of the filter cylinder 20, and is stopped by hitting the cover plate 22, and the exhaust gas is made to by-pass through the metal net of the filter cylinder 20 for the constitution. By this method, soot and sparks in the exhaust gas are removed by making them adhere to the cover plate 22 and the metal net of the filter cylinder 20, and the exhaust gas which is discharged from an exhaust gas outlet 18, is purified.

Method and apparatus for fire prevention

Abstract: of EP0885633The spark detector (10), fixed in or on the pipeline (1,1-1), emits an identification signal if an area of excessive temperature is identified, particularly a spark or a source of fire. A shut-off device (15) or cellular wheel sluice with a braking driving device (14,16), fixed in the pipeline downline from the spark detector, is designed to interrupt movement flow at the appropriate identification signal. During pneumatic movement of goods a gas shut-off device such as Zyklon is introduced into the sluice. A water spraying device (17-19), fitted between the spark detector and the shut-off device, douses any spark or source of fire.