Nippondenso Co., Ltd.

Koji Sakakibara

Hiroshi Haraguchi

Hirohiko Yamada

Koichi Kamabora

Naoki Kokubo

Hideki Yukumoto

Yoshihiko Hirata

Hideaki Ishihara

Toshiharu Iwata

Koichi Toyama

Hiroshi Okumura

Kenichi Nagase

Haruyasu Sakishita

Toshihito Nonaka

Kazuhiro Nakai

Seiitirou Nishikawa

A memory stores and holds both the number of crankshaft angle pulse signals occurring after detecting a reference portion when an engine stops and data relating to whether the reference portion which is supposed to be next detected upon re-start of the engine is a reference position of the camshaft. When the engine is re-started, it is determined whether a reverse rotation of the crankshaft across the reference position happened by comparing a predetermined value with the total obtained by adding the number of pulse signals stored in the memory and the number of pulse signals occurring until the reference portion is first detected again. When such reverse rotation happened, the reference position of the camshaft is shifted by 360.degree. CA. Therefore, regardless of whether such reverse rotation across the reference position happened or not, the engine timing cycle is again precisely synchronized.

Engine cycle timing and synchronization based on crankshaft angle

A knock sensing apparatus for an internal combustion engine which can detect a failure in a knock sensor signal system correctly even when a changeover operation due to hardware is performed at a place between a knock sensor and a band pass filter. In this knock sensing apparatus, the failure detection by a failure detecting circuit for detecting a failure in a signal system from knock sensors is invalidated for a predetermined period after one of the knock sensors has been changed over to the other knock sensor, or one of two kinds of pass bands of a band pass filter has been changed over to the other pass band, to prevent a decrease in failure detection accuracy due to the signal delaying action of the switched capacitor filter.

Knock sensing apparatus for internal combustion engine

An ignition timing control system for an internal combustion engine includes a basic ignition timing calculating unit for calculating a basic ignition timing of the engine and a low limit ignition timing calculating unit for calculating a low limit ignition timing of the engine, both being calculated according to an operating state of the engine. The system includes a retardation angle calculating unit for calculating a retardation angle that is retarded from the basic ignition timing. It also includes an advance angle calculating unit for calculating an advance angle that is advanced from a value corresponding to the low limit ignition timing depending on whether knocking is occurring in the engine. An operating state predicting unit is included for predicting an operating state of the engine where knocking is likely to occur. The system also includes an ignition timing control unit for controlling the ignition timing separately depending on whether a knocking is likely to occur in the engine.

Ignition timing control system for internal combustion engines

A signal rotor 6 rotates in synchronism with a crank shaft of the internal combustion engine. A pickup sensor 7 is disposed in a confronting relation to the signal rotor 6 to generate an angle signal S1 proportional to rotation of the internal combustion engine. An ignition signal producing means (31, 32) calculates an ignition timing on the basis of the angle signal S1 and generates an ignition signal (S41, S42) for igniting the internal combustion engine. A time mask means monitors a parameter representative of a battery voltage Vs, and prohibits the angle signal S1 from entering into the ignition signal producing means for a predetermined time in response to a detection of a predetermined amount fluctuation of the parameter.

Ignition timing control apparatus for an internal combustion engine

A knocking vibration detecting unit (1) and a knock deciding unit (c) are integrated, and the communications of a knock intensity between the knock deciding unit (c) and an engine controlling microcomputer (7) are carried out in combination of a change from the previous value of a signal line level. In the engine controlling microcomputer (7), the ignition timing is controlled by a predetermined retard angle in case of combination of no change of the present read signal line level from the previous signal line level. Thus, an internal combustion engine is prevented from any damage by relieving a failure without fail when a signal line (10) is troubled, while minimizing the influences of noises and reducing the space and size of an ECU.

Knock control system for internal combustion engine

A knock control system for an internal combustion engine derives a knock intensity indicative value Vpi from an output of a knock sensor and decides presence or absence of an engine knock by comparing the knock intensity indicative value Vpi and a knock decision level V.sub.KDi for controlling a knock control factor such as an ignition timing based on the decision. The system derives a value Si corresponding to a standard deviation of a distribution of a substantially logarithmic conversion value of the knock intensity indicative value Vpi, and a value V.sub.Mi corresponding to a median value of the above-noted distribution. The system derives the knock decision level V.sub.KDi based on the value Si and the value V.sub.Mi when the value Si is within a predetermined range. On the other hand, when the value Si deviates from the predetermined range, the system derives the knock decision level V.sub.KDi based on the value V.sub.Mi and a corrected value which is set smaller or larger than the value Si so as to prevent divergence of the knock decision level V.sub.KDi.

A combustion state detecting system for an internal combustion engine which is equipped with a combustion state detector for detecting a combustion state of said engine. The system also includes an amplifier having a plurality of amplification factors to amplify or attenuate a combustion signal obtained by the combustion state detector, the amplification factor of the amplifier being arranged to be switchable plural times on the basis of a detection result of the combustion state detector within a predetermined time period of a combustion cycle of the engine. The decision of the combustion state of the engine is made on the basis of an output of the amplifier generated within the predetermined time period. This arrangement allows an A/D converter to input a signal having as great as possible without overflow to improve the detection accuracy of the combustion state of the engine.

System for detecting combustion state in internal combustion engine

An engine control apparatus for discriminating each cylinder of an engine comprises a crank angle rotor (M1) having a configuration representing a crank angle of an engine; a crank angle sensor (M2) operatively associated with the crank angle rotor (M1) to generate a crank angle signal in accordance with the configuration of the crank angle rotor (M1). The configuration of the crank angle rotor (M1) includes first and second silent sections. The first silent section is cooperative with the crank angle sensor (M1) to constitute a part (M3) for generating a first level non-pulsation component of the crank angle signal. The second silent section being cooperative with said crank angle sensor to constitute a part (M4) for generating a second level non-pulsation component of the crank angle signal. There is further provided a cam angle rotor (M5) having a configuration representing a cam angle, which is operatively associated with a cam angle sensor (M6) for generating a cam angle signal to provide a plurality of different kinds of signal level sequences with respect to the first and second silent sections of the crank angle rotor. A cylinder discriminating device (M7) discriminates each cylinder of the engine on the basis of the level of the non-pulsation component of the crank angle signal and the signal level sequences of the cam angle signal.

Engine control apparatus for discriminating cylinders

The knock control apparatus for an internal combustion engine comprises a knock detecting unit, a knock intensity value detecting unit for detecting a knock intensity value from a knock detecting output signal of the knock detecting unit within a predetermined crank angle range, a unit for calculating a mean value of the knock intensity value, a unit for calculating a mean deviation between the knock intensity value and the mean value, a cumulative percentage point updating unit for updating a cumulative percentage point of the distribution of the knock intensity value, a first updated quantity calculating unit for calculating a first updated quantity based on the knock intensity value and the cumulative percentage point, a second updated quantity setting unit for setting a second updated quantity for updating the cumulative percentage point updating unit based on the magnitude relationship between the first updated quantity and the mean deviation, a knock decision level calculating unit for calculating a knock decision level based on an updation result of the cumulative percentage point updating unit, and a knock decision and control unit for deciding presence or absence of knocking based on a comparison between the knock intensity value and the knock decision level and controlling knock control factors based on a result of the decision, whereby both conditions of the response at the time of a transient operation and the stability during a normal operation, respectively, of the engine are satisfied so that an optimum knock decision level may always be obtained.

Knock control apparatus for internal combustion engines

A knocking control system for an internal combustion engine which is capable of surely detecting and reducing the knock of the engine. The knocking control system is equipped with a logarithmic conversion section for performing the logarithmic conversion of the effective knock intensity of the output signals of a knock sensor and a central value detecting section for detecting a central value in the logarithmic conversion value distribution. The deviation between the central value and the logarithmic conversion value is averaged to obtain an average value corresponding to the standard deviation of the logarithmic conversion value, thereby producing a knock decision level on the basis of the average value. The knock decision level is compared with the logarithmic conversion value so that the occurence of the knock is determined in accordance with the comparison result and the ignition timing of the engine is controlled in accordance with the determination result so as to reduce the knocking state.

Knocking control system for internal combustion engine

A control apparatus for an internal combustion engine having: a sensor for detecting a running condition of the internal combustion engine; a detector for detecting information indicative of the running condition in accordance with an output signal of the sensor; and a controller for controlling the internal combustion engine in accordance with a detection result of the detector, the controller communicating with the detector through a signal line is characterized in that: the detector includes sending circuit for sending the information by change in level of the signal lines from the last outputted information and the controller comprises: a reading circuit for reading level of the signal line; a memory for storing the read level of the signal line; a restoring circuit for restoring the information in accordance with the change of level read at this time from the level stored at the last time; a setting circuit for setting an amount of controlling of the internal combustion engine in accordance with restored result; and sub-controller for effecting a safety control when the level of the signal line read at this time does not change from that read out at the last time.

Knocking control apparatus for internal combustion engine

Knock generation control system for engines

A knock control system for the internal combustion engine is disclosed in which a knock intensity value V is detected from a signal produced by a knock sensor, a cumulative percentage point V.sub.P of distribution of a substantially logarithmic conversion value of the knock intensity value V is detected, a value S corresponding to the standard deviation of the substantially logarithmic conversion value is detected, and a knock decision level V.sub.KD is prepared on the basis of V.sub.P and S, thereby controlling knock control factors such as ignition timing and air-fuel ratio. The control system further comprises a device for deciding whether a predetermined period has passed after the engine enters specified operating conditions, a device for averaging knock intensity values, and an update quantity setting device for increasing the unit quantity of updating the averaging device and/or the cumulative percentage point detection device only while the predetermined period has not passed.

A knock control apparatus for an internal combustion engine which prevents variation of a control knock sound even if an output of a knock sensor is varied due to the variations in performance among different engines or knock sensors, aging of the engine or knock sensor or the like. A given correction quantity is added to an average value of an output signal of the knock sensor, and the sum is increased K times by a K-value varying with the operating conditions of the engine, thereby generating a knock discrimination level. In accordance with the presence or absence of knocking determined by comparing the knock discrimination level and an output signal of the knock sensor, a knock control factor, e.g., ignition timing, supercharge pressure or the like of the engine is controlled.

Knock control apparatus and method for internal combustion engines

In a system for controlling knocking in an internal combustion engine, a reference value to be compared with a knock sensor signal for determining the presence or absence of the knocking is corrected in accordance with the pattern of a distribution obtained by collecting the logarithmic transformation value of the maximum value of signal generated from the knock sensor signal within a predetermined engine rotational angle at an interval. This is based on the fact that the pattern of distribution represents the characteristic of knocking of the engine.

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Hekinan, Japan

Koji Sakakibara