Robert Boschgmbh

Rochus Knab

Robert H Entenmann

Siegfried Rohde

Jorg Bonitz

Herbert Schramm

Bernhard Miller

Walter Viess

Stefan Unland

Matthias Philipp

Jurgen Zimmermann

Hans-Ernst Beyer

Walter Kunzel

Wolfgang Kugler

Siegmar Forster

Herbert Winter

Alfred Mahlberg

Gunther Schmidt

Reinhard Aures

Geza Killi

Method for recognizing the power stroke of a cylinder of an internal

A first control unit of a multiple function control system for a motor vehicle engine controls a function, such as fuel injection, for which it is desirable to provide an engine load signal measured by the amount of air drawn or forced into the engine per unit of time, determined by what is generally known as an air quantity meter. A second control unit of the control system controls the timing of an electrical ignition system for which it has been conventional to supply an engine load signal derived from a pressure transducer. In order to dispense with the pressure transducer and to make both control units subject to adaptive correction of the air quantity signal, the output of the air quantity meter is furnished to the second control system for modification therein by the computation facilities normally included in modern ignition control systems so as to shift or expand the range of engine load signals obtained from the air quantity meter to provide the same degree of resolution as would be available from a pressure transducer. For adaptive correction, the engine-load-to-engine-speed characteristic at a predetermined position of the throttle valve at or near full load is stored, both to provide a plausibility check of the system when the engine is operating at or near full load, and to provide for a correction of the engine load signal of a kind which would minimize the difference between the actual and reference characteristic lines when the engine is operating at or near full load.

Control system for an extrinsic-ignition internal combustion engine

Control of a microcomputer performing a wide variety of functions in a motor vehicle in which the sequences of input and output signals intersect in time, instead of being performed by an elaborate input/output unit, is performed in the microcomputer itself with the help of a timing signal generator operating at a sub-multiple of the microcomputer clock frequency and producing a sequence of timing signals, each of which serve as an interrupt signal to the microprocessor of the microcomputer to initiate an interrupt program for scanning inputs and preparing outputs. After this short interrupt program, the main program is resumed. In the interrupt program each of a number of registers, respectively serving separate inputs or outputs, are decremented or incremented, having been set at particular values at the beginning of each interrupt program. Some registers are set at two different values in alternation in succeeding interrupt intervals. Engine speed determination is produced by counting the number of interrupt signals during the passage of a prolonged signal representing a certain angle of shaft rotation. The frequency of timing signals is varied in steps in accordance with engine speed.

Method of controlling a microprocessor to monitor input signals at

A cyclical input signal for the microcomputer of a motor vehicle is caused to reset the microcomputer for avoiding persistence of errors. Another portion of the same periodic signal can advantageously be furnished to the external interrupt input of the microcomputer.

Cyclical reset of vehicular microcomputers for economic error immunity

To recognize knocking conditions in signals derived from a knock sensor, which signals representative of knocking may be masked by background or noise signals, and to clearly distinguish the knocking signal from background or noise signals, the knocking signals are integrated with respect to measuring or strobing intervals during a predetermined angle of crankshaft rotation, digitized in an A/D converter (7) and then compared in a comparator (9) with the same signals which have been passed through a low-pass digital filter (8) to compare the integrated, digitized signal of a then occurring combustion process or event with similar signals of prior combustion processes or events to thereby recognize and distinguish knocking signal conditions from noise signal conditions; digital filtering and comparison as well as sequence timing can be carried out in a single microprocessor (FIGS. 2:14), earlier combustion events being weighted in accordance with the remoteness of their occurrence and/or engine speed and engine loading, the reference signal, for example, being generated in accordance with the formula:

Internal combustion engine knock sensing method and system

A knocking sensor (10) which provides output signals representative of combustion condition under knocking to thereby generate knocking signals which have mixed therewith noise or stray interference signals, and which also furnishes noise or stray interference signals under other than knocking combustion conditions, has its output connected to a plurality of parallel connected selective filters (2, 3). The filters have different pass band frequencies. One of the filters (3) is tuned to sense knocking frequencies, one or more other filters (2) being tuned to preferentially select noise or interference signals. A selection and discriminating circuit (10) having comparators (11) is provided connected to the filters to eliminate noise signals by comparing the signal level of the output received from the filters with a reference, which may be a dynamic reference, the outputs from the discriminators being processed in a logic circuit (15) to provide output signals (18) if (1) the filtered signal having the frequencies expected upon knocking exceeds a threshold level and (2) the filtered signal having the frequency band of the stray, or noise signals is below a threshold level and, preferably, a knocking signal persists for a time in excess of a time interval as determined by a timing circuit (16). Preferably, non-linear circuits such as logarithmic circuits (4, 5), are connected between the outputs from the filters (2, 3) and the comparators (11, 12) of the selection or recognition or discriminating circuit (10).

Internal combustion engine knocking sensing and recognition system

To provide a signal representative of angular crankshaft position from an ignition distributor, independently of change of ignition timing, the ignition distributor includes a further or additional rotating transducer system (8, 9, 10, 11), for example a rotating disk (8) positively coupled to the shaft (3) of the distributor. The disk (8) carries markers (10) which are picked up by an optic, magnetic (Hall generator) or inductive pick-up (9). To provide a reference marker output, for example a reference, e.g. TDC position of a reference piston, the rotating disk (8) can carry an additional reference marker (10a) picked up by a reference pick-up (9a) which can be similar to the other pick-ups used in the construction. The specific crankshaft position signals are especially suitable and desirable if the engine is coupled to an engine knock sensing and knock prevention system (KS).

Ignition pulse and crankshaft angle pulse generator and distributor

A knocking sensor provides output signals which are compared in a comparator (14) with a reference (16), knocking signals (FIG. 3: U17) exceeding the reference (U16); during predetermined cyclically recurring test intervals (FIG. 2: 19), for example after each 1000 ignition events, a test signal is generated at a terminal (15) of a microprocessor (12) and applied to the comparator (14) to lower the reference level (16), so that noise signals will cause a simulated, or pseudo knocking signal to be generated. Simultaneous occurrence of the simulated, or pseudo knocking signal and test signals indicates appropriate function of the knocking system; failure of the pseudo knocking signal to occur with the lowered reference generates control output from the microprocessor, for example by retarding ignition of an ignition system (13).

Engine knock control supervisory system

An amplitude envelope signal is derived from the output of an engine-knock sensor. Either the peak value of the envelope signal or its steepest rate of rise initiates the operation of a delay circuit providing a signal after a delay that is dependent upon the magnitude of the peak value or rate of rise. The envelope signal is also compared with a reference signal responsive to or representing or simulating background noise levels, and a comparison signal is produced when the envelope signal exceeds the reference signal. Engine-knock recognition is determined by the coincidence of the comparison signal and the delayed signal, and may be subjected also to a measurement window criterion which limits the appearance of an engine-knock signal to a particular arc of crankshaft revolution.

Engine-knock detection method and apparatus

One or more temperature sensing elements, for example thermo couples (13, 14, 16, 17), NTC or PTC or resistance wires (18) or capillary fluid temperature sensor elements (20, 21) are located on or in the immediate vicinity of a portion of the inner wall of the combustion chamber, for example and preferably by being integrated within a head liner or facing (15, 15') of the cylinder head gasket or seal (10). The output signals, in electrical or hydraulic form are connected to an evaluation stage (E, E') which determines if the temperature within the cylinder, representative of knocking, has exceeded a predetermined level. Preferably, a speed signal (n) is derived from the engine so that the signals from the sensing elements can be strobed with respect to the time within the engine cycle during which ignition may or is intended to occur so that temperature variations due to normal engine operating strokes are eliminated from the systems output.

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Kornwestheim, Germany

Rochus Knab