Robert Boschgmbh

Siegfried Rohde

Robert H Entenmann

Jorg Bonitz

Rochus Knab

Bernhard Miller

Walter Viess

Stefan Unland

Herbert Schramm

Matthias Philipp

Walter Kunzel

Oskar Torno

Ulrich Rothhaar

Jurgen Zimmermann

Hans-Ernst Beyer

Bernhard Stengel

Alfred Mahlberg

Wolfgang Kugler

Siegmar Forster

Herbert Winter

Hans Rauch

Gunther Schmidt

Reinhard Aures

Geza Killi

Robert Entemann

A method for recognizing a power stroke of each cylinder in a four-stroke engine calls for sensing a parameter of a cylinder in the engine for producing a signal of the parameter, the parameter being selected from the group consisting of pressure and knocking, and comparing the signal with a threshold value for determining whether the signal exceeds the threshold value and thereby is indicative of the cylinder being in a corresponding combustion stroke. In addition to sensing the pressure and knocking of the cylinder, sensing of sound signals from the cylinder is also employed in order to determine power and intake strokes of the cylinders.

Method for recognizing the power stroke of a four-stroke engine

Adaptive closed-loop knock control for a turbocharged engine

Process and device for boost control

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

To provide for adaptive change of the operating characteristics of an engine, so that it will operate at its optimum effectiveness, just below the knocking limit, while reliably preventing knocking thereof, a computer receives engine data from respective sensors and a knock sensor (5), from which the computer calculates, based on data stored in a memory (3), operating parameters for the engine (1). The engine is, for example, an Otto-type internal combustion engine (ICE) or a Diesel engine. The operating characteristics, as computer-modified based on sensed knocking, and the modification data, are then placed into the memory to modify the basic memory content. Preferably, the memory has a basic memory content section and a programmable differential or modification section, in which algebraic constants or modifying factors are stored, based on actual experience of operation of the engine, just under the knocking limit. Thus, the stored data on which the engine operation is controlled is continuously up-dated based on actual engine operating conditions, and thereby compensating for ageing, wear and tear of parts, different fuels, or environmental conditions or the like. The computer can likewise recognize substantial deviation of the modified characteristics from the basic characteristics and, if the modifications exceed a certain limit, provide an error or malfunction output signal to an error or malfunction output indicator (9, 4) and go into a fail-safe mode.

Engine knock control method and system with fail-safe mode

To prevent slow reestablishment of operating conditions which might lead to knocking of an internal combustion engine if the internal combustion engine operates under transient conditions, for example under conditions of rapid acceleration, the reestablishment rate of an operating control signal, for example ignition timing which, after retardation, is again advanced, transient speed changes are sensed in a differentiator (17) and, if so sensed, cause reestablishment of prior operating condition at a faster rate (f3) than otherwise, normally set into the system (see f2, FIG. 2). Additionally, the reference level of a comparator which compares sensed engine vibration signals with a reference can be increased so that, due to increased engine noise, erroneous knocking signals will not be generated by the comparator. Function generators (18, 19) which provide changed reference levels or signal weighting levels as a function of the degree or characteristics of transience, are preferably provided so that the system will respond dynamically.

Method and system to prevent knocking operation of an internal

A demodulated audio signal for detection of engine-knock is digitalized to produce a sequence of digital signals corresponding to the various cylinders of the engine in turn. These digital signals are recursively filtered by applying a factor k to a newer value and its complement (1-k) to an older value from the same cylinder or a value obtained therefrom by partial filtering and the sum of the two factor-modified terms is formed to provide a reference value with which the most recent digital signal is compared, to produce an indication of engine-knock when the latter exceeds a reference value by a predetermined amount. The factor k is varied in accordance with acceleration of engine speed or with the level of signals from the vibration sensor that exists before the application of automatic gain control prior to integration. The system, which can be implemented mostly in the software of a microcomputer, also includes provisions for adjusting from time to time minimum reference signal values for each of the cylinders, which are to be substituted for the reference signal values contemporaneously produced by recursive filtering if the latter fail to exceed the former in magnitude, and also for determining, at appropriate times, failures of the knock detection system from the absence of normal variations between the integrated signals from the respective cylinders, and providing corrective action in response thereto.

Method for detecting engine knock in internal combustion engines

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.

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Schwieberdingen, Germany

Siegfried Rohde