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Showing papers on "Spark (mathematics) published in 1992"


Journal ArticleDOI
TL;DR: This paper presents a new approach to concurrent engineering, namely the use of artificial intelligence constraint networks to advise the designer on improvements that can be made to the design from the perspective of the product's life-cycle.
Abstract: This paper presents a new approach to concurrent engineering, namely the use of artificial intelligence constraint networks to advise the designer on improvements that can be made to the design from the perspective of the product's life-cycle. The difficulties associated with performing concurrent engineering are reviewed, and the various approaches to concurrent engineering are discussed. The requirements for a system to support concurrent engineering are indicated. An overview of constraint networks is given and this leads into a description of SPARK, an artificial intelligence constraint network systems for concurrent engineering. The operation of SPARK is illustrated by considering an example application of printed wiring board manufacture. The advantages of SPARK include being flexible enough to allow the designer to approach a problem from a variety of viewpoints, allowing the designer to design despite having incomplete information, and being able to handle the wide variety of life-cycle informatio...

80 citations


Journal ArticleDOI
TL;DR: In this article, the breakdown stage of a spark discharge in air is analyzed, and the short duration of the burst is shown to be a function of the spark's short duration.

67 citations


Patent
28 Feb 1992
TL;DR: In this paper, a closed chamber for receiving a carrier gas (12) flowing therethrough between inlets (18) and outlets (36), and the carrier gas is exposed to a pair of electrodes (31, 32) forming a spark across the chamber (21) and through the gas.
Abstract: A spark detection apparatus is set forth and incorporates a closed chamber (21) for receiving a carrier gas (12) flowing therethrough between inlets (18) and outlets (36), and the carrier gas (12) is exposed to a pair of electrodes (31, 32) forming a spark across the chamber (21) and through the carrier gas. Compounds of interest interact with the spark. The spark forms a diffusion of electrons or alternately ions during the spark distributed thereafter. The chamber (21) includes a detector electrode (26) spaced from the spark. High mobility particles (primarily electrons) are observed almost instantaneously with the spark while low mobility ionic particles diffuse more slowly after the termination of the spark. Using an inert carrier gas (12), high energy metastable molecules are dispersed and give up energy over time after the spark. The ouput is obtained from the electrode (27) during, immediately after, or after a long delay relative to the spark. Another alternate output is obtained from the observed spectra during the spark and after the spark.

48 citations


Journal ArticleDOI
TL;DR: In this article, the formation process of flame kernels produced by composite sparks in a quiescent propane-air mixture is numerically simulated by using a set of partial differential equations on two-dimensional cylindrical coordinates.

42 citations




Patent
06 Apr 1992
TL;DR: In this article, an engine performance optimizing system is described that requires only a single engine parameter (shaft revolution time) to be measured, and correction factors can be computed and used to adjust the spark setting, the air flow and/or the recirculation rate in a way that causes engine performance to be enhanced in terms of fuel economy and lowered emissions.
Abstract: An engine performance optimizing system is described that requires only a single engine parameter (shaft revolution time) to be measured. By simultaneously dithering spark timing, air/fuel ratio and/or EGR rate in accordance with a predetermined cyclic pattern, and measuring shaft speed during each discrete phase of the dither cycle, correction factors can be computed and used to adjust the spark setting, the air flow and/or the recirculation rate in a way that causes engine performance to be enhanced in terms of fuel economy and lowered emissions.

26 citations



Journal ArticleDOI
TL;DR: In this article, the hydrodynamic influence of an igniting spark upon both the initial size and the initial growth of a flame kernel can be approximately predicted from knowledge of three spark parameters: energy, duration, and physical length.

19 citations



Proceedings ArticleDOI
01 Oct 1992

Journal ArticleDOI
01 Apr 1992
TL;DR: In this article, the authors investigated the exhaust emissions from two-stroke cycle spark ignition engines and the means being investigated to reduce them, and the results showed that the simple 2-stroke engine has inherently low leve...
Abstract: This paper is concerned with the exhaust emissions from two-stroke cycle spark ignition engines and the means being investigated to reduce them. The simple two-stroke engine has inherently low leve...


Journal ArticleDOI
TL;DR: In this paper, a quasistationary spark carbon ion source has been fabricated and tested with two systems of electric power supply, and it was found that the ion charge state distribution is similar to the HF spark with a discharge current of 2 kA (1.5-2.0 kA).
Abstract: A spark carbon ion source (SIS) has been fabricated and tested with two systems of electric power supply. It was found that in the quasistationary spark (inductive energy storage scheme), and for a discharge current of ∼2 kA and timp∼100 μs, the ion charge state distribution is similar to the HF spark with a discharge current of 2 kA (1‐MHz LC‐circuit scheme). A total pulse carbon ion current of about 500 mA has been obtained from the quasistationary spark. The C+3 ion current was about 300 mA and the C+4 ion current ∼100 mA. The noise amplitude of the total ion current is no more than 10% in this mode of operation. The production of highly charged ions is explained by an increased potential drop in the discharge gap (60–100 V) for currents of 1.5–2.0 kA. It is shown that the quasistationary spark mode is accompanied by an occurrence of a stable anode spot while electrode evaporation increases and the vacuum spark is transformed into a high pressure spark discharge, leading to a shift of the ion spectral ...

Book
01 Jan 1992



Patent
30 Apr 1992
TL;DR: In this article, a method for controlling knock on an internal combustion engine is described, which includes the steps of determining a maximum value of knock and determining whether conditions are right for updating the maximum value.
Abstract: A method is provided for controlling knock on an internal combustion engine. The method includes the steps of determining a maximum value of knock and determining whether conditions are right for updating the maximum value of knock. The method also includes using an unmodified spark advance if conditions are not right for updating the maximum value of knock and modifying the spark advance if conditions are right for updating the maximum value of knock.

Patent
16 Oct 1992
TL;DR: In this article, an instant subsequent to the extinguishing of a spark produced in a spark plug for igniting the air/fuel mixture contained in a cylinder of an engine is determined.
Abstract: The device comprises a) means (16) for determining an instant subsequent to the extinguishing of a spark produced in a spark plug for igniting the air/fuel mixture contained in a cylinder of the engine, b) means (7, 9) for therefore powering the spark plug (11 to 14) with a predetermined electric voltage capable of giving rise to the passage of a current through this spark plug if the gas present between the electrodes of the spark plug results from an ionising combustion triggered by the spark, and c) means (10) for detecting the current which may be passing through the spark plug. The absence of current signifies nonionisation of the gases contained in the cylinder, and therefore the occurrence of a misfire. Application to the protection of a catalytic converter containing an oxidising catalyst for oxidising the exhaust gases of the engine.


Patent
07 Jan 1992
TL;DR: In this article, a de-driver circuit was proposed for noncontact spark-discharge imaging systems, which can rapidly produce short-duration, highvoltage pulses that cause the discharge of a spark to the surface of a printing plate.
Abstract: Electrode-driver circuits for use with non-contact spark-discharge imaging systems. The circuits rapidly produce short-duration, high-voltage pulses that cause the discharge of a spark to the surface of a printing plate; they feature short rise times, rapid operation and clean decays, thereby facilitating high-speed spark-discharge imaging.


Proceedings ArticleDOI
29 Jun 1992
TL;DR: In this article, a study was conducted to determine the ability of neural networks to extract high level control information from cylinder pressure data, and various experiments were performed using neural networks for pattern recognition on a series of data files consisting of cylinder pressure versus crank angle.
Abstract: A study was conducted to determine the ability of neural networks to extract high level control information from cylinder pressure data. Various experiments were performed using neural networks for pattern recognition on a series of data files consisting of cylinder pressure versus crank angle. The goal of these experiments was to estimate spark timing based on the cylinder pressure signature-all other engine parameters were held constant during the data collection process. Test results indicate that an approximate spark time value can be obtained using cylinder pressure data as the inputs to a neural network and spark timing as the output. >

Patent
24 Sep 1992
TL;DR: In this article, the authors propose an automatic adaptation of spark timing in dynamic processes for a spark-ignition internal combution engine whereby, in a dynamic process, dynamic spark timing retardation values DELTA alpha Z1 are stored in an engine speed characteristic curve and added to a predetermined spark timing value alpha V in order to retard the spark timing.
Abstract: The invention discloses automatic adaptation of spark timing in dynamic processes for a spark-ignition internal combution engine whereby, in a dynamic process, dynamic spark timing retardation values DELTA alpha Z1 are stored in an engine speed characteristic curve and added to a predetermined spark timing value alpha V in order to retard the spark timing. After a waiting time tW, the spark timing is advanced again to the predetermined value alpha V. The stored dynamic spark retardation values DELTA alpha Z1 can be varied in a kind of learning process. If a combustion with pinking occurs during an observation time tB, a dynamic spark retardation value DELTA alpha Z1 is increased to a certain retardation correction value or, in the absence of pinking during the observation time, it is reduced to a given advance correction value. The spark timing can thus be adapted rapidly in dynamic processes to achieve optimal operation and a low tendency to pinking.

Patent
04 Nov 1992
TL;DR: In this paper, a distributorless ignition system is described for a spark ignited internal combustion engine which reduces the risk of spark plug fouling, and includes circuitry for exciting the coil to generate sparks before or after an engine run, for preventing the formation of a deposit on the spark plug or burning off any existing deposit.
Abstract: A distributorless ignition system is described for a spark ignited internal combustion engine which reduces the risk of spark plug fouling. In addition to the usual ignition circuit (10, 12, 14, 16) which generates sparks in synchronisation with the position of the crankshaft while the engine is running for initiating charge combustion, the system of the invention includes circuitry (18 to 26) for exciting the coil (16) to generate sparks before or after an engine run, for preventing the formation of a deposit on the spark plug or burning off any existing deposit.


Patent
08 May 1992
TL;DR: In this paper, the authors proposed to improve self-cleaning work of a spark plug and prevent smoking and wetting damage of the spark plug, and ignite the dense air-fuel mixture securely for combustion by providing a current break type ignition and a capacity discharge type ignition.
Abstract: PURPOSE:To improve self-cleaning work of spark plug, and prevent smoking and wetting damage of the spark plug, and ignite the dense air-fuel mixture securely for combustion by providing a current break type ignition means and a capacity discharge type ignition means CONSTITUTION:A spark plug 50 is connected to an ignition device 52 electrically This ignition device 52 consists of a current break type ignition means 53 and a capacity discharge type ignition means 54 At this stage, electric spark is thrown from the ignition means 53 to the spark plug 50 at a point near a compression top dead center to ignite the air-fuel mixture for combustion When a piton is pushed down by the combustion explosion of the air-fuel mixture and an exhaust port starts to be opened, the electric spark is thrown from the ignition means 54 to the spark plug 50 Consequently, carbon adhered to an electrode of the spark plug 50 can be burned off for elimination Besides, since the spark connection time of the ignition means 53 is long, chance of igniting the air-fuel mixture is increased

Patent
31 Jul 1992
TL;DR: In this paper, a secondary voltage control circuit is proposed to reduce quenching action of a flame nucleus so as to improve ignitability by providing an ignition coil, switchboard, switching circuit, and switching circuit.
Abstract: PURPOSE:To reduce quenching action of a flame nucleus so as to improve ignitability by providing a secondary voltage control circuit, which places duration time of an induction component of a spark discharge and spark energy in a specific condition, while specifying a diameter in a point end part of a center electrode of a spark plug. CONSTITUTION:In this spark plug 1, a firing part, which is a point end of a center electrode 11, is made of platinum alloy or iridium to provide 0.3 to 0.6mm diameter. An ignition circuit 2 is constituted of an ignition coil 3, distributor 4, switching circuit 5 and a secondary voltage circuit 6. Here, the secondary voltage control circuit 6 is constituted such that duration time of an induction component of a spark discharge is 1.0msec or less and 0.2msec or more with spark energy 20millijoule or less and 5.0millijoule or more, when an engine speed is 1000rpm or less, to reduce the spark energy while shortening the duration time according to increasing the engine speed further with generated voltage by the ignition coil maintainable.