EP1756412B1 - Detection of analogue vehicle signals synchronous with the crankshaft - Google Patents

Abstract

Synchronization of the angle position of the crankshaft of a motor vehicle with the internal clock of a engine control device is often imprecise and complicated and is often fraught with difficulties, particularly with regard to the detection and processing of external sensor signals. The invention relates to a engine control device wherein the angle position of the crankshaft is initially detected and converted into an electronic trigger signal in a trigger converter. The electronic trigger signal controls the detection and the analog-to-digital conversion of an analog signal, particularly an analog sensor signal. Control occurs in such a way that data can only be detected when a specific trigger signal is present or that data can only be continuously detected and processed when a specific trigger signal is present.

Description

The invention relates to a method and a device for receiving analog signals, in particular analog sensor signals, which are related to an angle signal, in particular the angle signal of a crankshaft in internal combustion engines. Such devices and methods are primarily used to record analogue measured values in engine control units (ECUs).

The operation of modern internal combustion engines in the automotive industry is unthinkable without the use of high-performance computer systems. In particular, the increasingly restrictive requirements for pollutant emission in the form of corresponding legal regulations make the use of sophisticated computer and control technology for the precise adjustment of the combustion mixture and the ignition timing required. In particular, numerous sensor signals, such as the signals of oxygen or temperature sensors must be processed in real time.

These tasks are essentially taken over by the engine control unit (ECU), the most powerful computer system on board a motor vehicle. In addition to one or more microprocessors (usually called "embedded systems", Engl. Embedded Systems) are a number of other electronic components, such as analog-to-digital converter (AD converter) or electronic filter modules, integrated into the corresponding housing of a motor control device , From the numerous sensor signals (for example with the aid of tables, so-called look-up tables), the engine control unit calculates the corresponding control signals and setting parameters, such as the optimum time of ignition or the optimal duration of a fuel injection.

In particular when acquiring analog measured values (for example the measured values of pressure, temperature or oxygen sensors), the time synchronization of the measurement plays a significant role. Although simple computer systems include internal clock systems (clock), which can be used in principle for the time recording and synchronization of the measured value acquisition. However, it should be noted that the measured values must typically be recorded in each case in relation to a defined operating state of the engine. As an indicator for the operating condition of an engine, in particular the angular position of the crankshaft has been established.

Depending on the type of internal combustion engine, the angular position of the crankshaft exactly defines the position of the pistons in each individual cylinder. For example, a complete cycle of a typical four-cylinder internal combustion engine includes two complete revolutions of the crankshaft, ie angles from 0 ° to 720 °. After two revolutions (720 °), each cylinder of the engine has passed through its cycle once. The cylinders work sequentially, ie each cylinder only operates within a specific section within a complete cycle. Such a period of time is also referred to as a segment. Each segment corresponds to a range of the angular position of the crankshaft, which results from the entire angular range (for example, 720 °), divided by the number of cylinders. Thus, a segment of a four-cylinder internal combustion engine comprises an angular range of 180 °. The first segment thus corresponds to angular positions from 0 ° to 180 °, the second angular positions from 180 ° to 360 °, etc.

The angular position of the crankshaft is typically detected by means of a so-called encoder disc on the crankshaft. This encoder disk is usually a metallic toothed disk whose rotation is usually detected by means of an inductive sensor. Typical encoder discs for four-cylinder engines, for example, have 60 teeth (or 58 after deduction of the two "tooth spaces"), which corresponds to a number of 120 teeth for a complete cycle of 720 °, ie one tooth per 6 ° angular position. In this case, as soon as a tooth of the encoder disc approaches an induction coil of the sensor, the magnetic field in the coil changes, whereby a current is induced in the coil. The frequency of this time-varying current is a measure of the speed of the crankshaft. Other types of sensors, such as optical or magnetic sensors, are basically usable.

In order to be able to conclude from the periodic signal of the rotational speed measurement on an absolute position of the crankshaft, gaps are usually built into the teeth of the encoder disc, the gaps typically include two teeth. In this way, the position of the crankshaft and thus an important parameter of the operating state of the internal combustion engine based on the signal can be determined exactly.

The angular position of the crankshaft or the rotational speed is synchronized in conventional engine control devices at regular intervals with the internal clock of the engine control unit. The detection of sensor signals and the calculation based thereon or generation of corresponding parameters and control signals takes place as a function of the internal clock of the engine control unit.

These calculations, however, are time consuming and put a heavy burden on the processor due to computing power and memory overhead. For example, at a certain engine speed, the angular position of the crankshaft must first be detected and synchronized with the engine control unit's internal clock. Then, relative to the internal clock of the engine control unit, measurement data of the various sensors are detected.

Up to now, this measurement data acquisition usually takes place with a fixed sampling rate, wherein sampling rates between 5 and 10 microseconds are typical. For example, every 10 microseconds, a new analog value of a particular sensor signal is detected. At a speed of 1000 rpm in a four-cylinder engine, i. H. a cycle time (time for a 720 ° rotation) of 120 milliseconds and thus a segment time of 30 milliseconds, this corresponds to 3000 analogue measurements per sensor, cylinder and segment. At lower speeds, the number of readings per sensor, cylinder and segment increases accordingly. For example, 6000 analogue readings per sensor, cylinder and segment are already recorded at 500 rpm. This represents an enormous storage load for the engine control unit.

Although in principle it is possible to adjust the sampling rate of the measurement signal acquisition of the speed of the motor. However, the limited possibilities of configuring existing AD converters in embedded microcontrollers severely limit these possibilities.

From these measurement data, optimum control signals are then calculated, which, however, in turn must be output in precisely determined (for example, calculated by the engine control unit) angular positions of the crankshaft. For this purpose, therefore, the optimal time points in the time base of the engine control unit must be calculated and then in turn converted into corresponding angular positions. This complex calculation and generation of control signals loads the microprocessor of the ECU, which typically has only a clock frequency of 40 MHz and a storage capacity of 256 kilobytes, extremely.

The object of the invention is therefore to provide a method and a device by means of which the detection and processing of analog measurement data in engine control devices is improved.

This object is achieved by the invention with the features of the independent claims. Advantageous developments of the invention are characterized in the subclaims.

An engine control device is proposed which has means for detecting an angular position of a crankshaft and means for converting the angular position of the crankshaft into an electronic trigger signal. Furthermore, the engine control unit should have means for detecting at least one analog signal, in particular an analog sensor signal, including at least one signal input for analog signals, at least one analog-to-digital converter for converting the at least one analog signal into at least one digital signal and at least one control device , This control device should, depending on the electronic trigger signal, the detection of the at least one analog signal on or off and / or start or stop.

The term "capture" is to be interpreted broadly. It can, for example, to measure, caching (sampling), analog-to-digital conversion, save or a combination of these processes (possibly with further modifications of the signals) act. Alternatively, a permanent analog-to-digital conversion can take place, whereby only the storage of the converted data is understood as "detection". By "means for detecting" can accordingly be understood, for example, a corresponding sensor, an analog-to-digital converter, a corresponding signal conversion or intermediate storage or even only a part of these devices.

The control device may be, for example, a trigger input, which in particular has means for generating a trigger signal, for. B. a trigger converter, can interact.

An engine control device is to be understood as a system for controlling an internal combustion engine. This does not necessarily have to be a physical and / or electronic unit, but may in particular also be a combination of interacting but spatially separate components. In particular, the means for converting the angular position of the crankshaft into an electronic trigger signal and the means for detecting the at least one analog signal may be wholly or partly integrated in an integrated electronic circuit, in particular a so-called application-specific integrated circuit (ASIC).

The digital electronic trigger signal may in particular be a periodic, for example rectangular, signal, for example a TTL signal. Thus, in particular, a period of this signal correspond to a period on the encoder disk, ie the distance between two teeth on the encoder disk (see above) and the resulting angular rotation of the crankshaft. In the above-described example of the four-cylinder engine with a donor disk of 60 teeth thus corresponds to a period of an angular rotation of the crankshaft of 6 °.

Since, as described above, missing on the encoder disc usually one or more teeth, it can be concluded from the corresponding gaps in the trigger signal to an absolute angular position of the crankshaft.

The trigger signal can additionally be modified accordingly. An adjustment of the signal level, a frequency filtering, a frequency multiplication and / or a phase shift has proven to be particularly advantageous. For example, frequency filtering may be required to eliminate higher frequency or low frequency noise (vibrations, harmonics, etc.). Under a frequency multiplication is a modification of a periodic Signal is understood to mean that the frequency of the signal is multiplied by a multiplier (which is typically a rational, in particular a natural number between 0 and 1 or greater than 1).

Also, the conversion of the trigger signal into a new trigger signal by means of a predetermined function is conceivable. Thus, for example, from the original trigger signal by means of a counting device, a predetermined number of periods (for example, a predetermined by a computer program) can be selected during which the new trigger signal assumes the value "high". In this way, a trigger signal can be generated, which assumes the value "high" only in very specific angular positions of the crankshaft. Or it can be output from a certain angular position for a fixed predetermined period of time, the signal "high".

In particular, the modification of the trigger signal of the speed of the crankshaft can be adjusted. Thus, for example, a frequency multiplication of a frequency signal F periodic trigger signal carried out such that the frequency F of the new trigger signal less than proportional to the speed D increases. In other words, the quotient of frequency F and speed D decreases with increasing speed. This sinking does not have to be continuous, but can also be done in discrete stages, for example. If the acquisition of analog measurement data is controlled with this new trigger signal (see below), this can be used: Targeted adjustment of the frequency multiplication so that a constant load of the memory and / or computing capacity of the engine control unit per unit of time over the entire speed range. The adjustment of the trigger signal to the speed can be done during operation of the engine control unit.

The conversion of the angular position of the crankshaft into a corresponding trigger signal according to one of the described methods In particular, it can also be purely hardware-based, that is to say without the use of computational algorithms in separate electronic components. The use of a microprocessor or an additional load on the processor capacity of an existing processor (see below) by the formation of the trigger signal is thereby avoided.

The at least one analog signal can be, in particular, an analog signal of a sensor, for example an oxygen, temperature or pressure sensor, it is also possible to detect a plurality of analog signals, in particular the signals of a plurality of sensors. In this case, in particular, the use of one or more switches, which can switch the detection between the individual analog signals. In this way, successively or alternatively or in parallel, the signals of several sensors can be detected. The switching between the detection of the individual signals can be controlled in particular by a microcomputer, so that at predetermined times in each case the analog signals of predetermined sensors are detected. In particular, the switching can also be controlled by the electronic trigger signal (which, mutatis mutandis, can also consist of several correlated individual signals).

In addition to the analog-to-digital converter, the means for detecting the at least one analog signal may also include a device for data processing (in particular a microprocessor) and means for adapting or changing the analog signals, in particular means for frequency filtering. For example, the microcomputer may be the arithmetic unit (for example, a CPU including a memory) of a commercial integrated circuit for motor control.

The control device may in particular be a trigger input of the analog-to-digital converter or else to act a trigger input of the data processing device. This trigger input is connected to the means for converting the angular position of the crankshaft into an electronic trigger signal. It does not necessarily have to be a physical electronic connection, but also, for example, a wireless connection (eg infrared data transmission) is conceivable. In this way, the above-described trigger signal generated from the angular position of the crankshaft or a trigger signal derived therefrom is used to control the detection of the analog signals.

The digitized signals can then be further processed by means of the data processing device. For example, corresponding control signals for the engine control can be generated and output from a multiplicity of sensor signals with the aid of stored functions and parameters.

The engine control unit described with the crankshaft synchronously triggered data recording has the decisive advantage over the conventional motor control devices with a constant or predetermined sampling rate as described above, that the detection of the at least one analog signal does not take place at fixed predetermined times with fixed repetition rates (sampling rates). An excessive burden on the computing and storage capacity of the engine control unit, especially at low speeds is thereby prevented. The detection of the analog signals rather takes place in dependence on the actual angular position of the crankshaft and thus the actual operating state of the internal combustion engine. For example, certain sensor signals (for example, the signal of a pressure sensor in cylinder 2 of a four-cylinder engine) can only be used at the actually interesting times (ie, only in segment 2 in which the second cylinder is operating, ie, for example, in the angular range of the crankshaft between 180.degree ° and 360 °). Uninteresting data, ie analog signals in angular positions of the crankshaft, which are uninteresting with respect to, for example, a particular sensor, so are not detected from the outset, whereby the memory and processor load is greatly reduced.

A processor capacity and memory-consuming conversion of the angular position of the crankshaft or the speed in an internal time system of the engine control unit can be omitted. For the generation of the trigger signals only hardware is required, no software effort. The processor is thus relieved. Even a constant high load at low speeds does not occur.

Also, the accuracy of the system is considerably increased by the crankshaft synchronous measurement data acquisition. The acquisition of the measured data can be done at fixed angular positions, which is much more precise than a time-controlled recording with possibly required, subsequent interpolation.

In order to avoid that the described advantages turn into the opposite (namely in an excessive load of the engine control unit at high speeds), in addition, as described above, an adaptation of the sampling rate or a reduction of the measured data with increasing speed by appropriate adjustment of the trigger signal to the speed. In this way, a uniform amount of data and processor load over the entire speed range can be achieved.

In order to further relieve the memory and the processor of the data processing device, preprocessing of the raw data can already take place in the analog-to-digital converter, which converts the analog signals of, for example, one or more sensors into digital signals. Such preprocessing can in particular be frequency filtering and / or a statistical analysis of the analog or already digitized data. For example, an averaging of the data over a certain period of time or over a certain number of measured values can already take place. By this preprocessing, the amount of data, which is transmitted for example from the analog-to-digital converter to the microprocessor, significantly reduced.

Also in the preprocessing of the acquired data, the crankshaft synchronous triggering of the acquisition of the analog data according to one of the methods described above again an essential advantage. Since the trigger signal by means of which the recording of the analog data is triggered, information about the angular position and the speed of the Crankshaft contains, for example, the analog or digital signal can be averaged directly over a certain angular range of the crankshaft. A conversion of the angular positions into time signals is no longer necessary.

Also, a speed-dependent preprocessing of the data is conceivable, for example by the time or angular position range over which an analog or digital signal is averaged, is shifted in dependence on the speed. For example, the timing of the ignition can be heavily dependent on the speed. It may be of interest, for example, to detect the pressure in a certain cylinder in each case in a certain angular range averaged relative to the ignition time. By means of the crankshaft-synchronous triggering of the signal detection this is again possible without the use of computing capacity of the microprocessor and without conversion of the trigger signal into a time signal.

During preprocessing of the detected signals, it is also possible, for example, to adapt a predetermined approximation function to the acquired data. Accordingly, then, for example, instead of the data only the approximate function or the parameter characterizing the proximity function is forwarded from the analog-to-digital converter to the device for data processing. Here, too, the information about the angular position or the speed of the crankshaft can play a role, for example as one of the parameters of the approximation function. This type of preprocessing of the signals also contributes significantly to the reduction of the required processor and storage capacity.

Another advantage of the motor control device described is the fact that the device can be implemented with existing microprocessors and electronic components. Both microprocessor with trigger input for motor control devices and analog-to-digital converters with trigger input are commercially available. An expensive and expensive new development of such components is not required.

Furthermore, a method is proposed for the crankshaft-synchronous detection of analog signals, in particular analog sensor signals, in which first the angular position of a crankshaft is detected. The detected angular position of the crankshaft is converted into at least one electronic trigger signal. Furthermore, at least one analog signal, in particular an analog sensor signal, is detected. In this case, the at least one analog signal is converted into at least one digital signal. The detection and / or the analog-to-digital conversion of the at least one analog signal is controlled by means of the trigger signal.

• Die Erfassung und/oder die Analog-Digital-Wandlung wird dadurch ausgelöst, dass das Triggersignal einen vorgegebenen Pegel erreicht, überschreitet oder unterschreitet.
• Die Erfassung und/oder die Analog-Digital-Wandlung wird ermöglicht, solange das Triggersignal einen vorgegebenen Signalpegel mindestens erreicht und/oder überschreitet, wobei anderenfalls die Erfassung und/oder Analog-Digital-Wandlung verhindert wird.
• Die Erfassung und/oder die Analog-Digital-Wandlung wird ermöglicht, solange das Triggersignal einen vorgegebenen Signalpegel unterschreitet und/oder nicht überschreitet, wobei anderenfalls die Erfassung und/oder Analog-Digital-Wandlung verhindert wird.
• Die Erfassung und/oder die Analog-Digital-Wandlung wird bei einem periodischen Triggersignal während einer vorgegebenen Anzahl Perioden ermöglicht und andernfalls verhindert.
• Die Erfassung und/oder die Analog-Digital-Wandlung wird ab einem vorgegebenen Triggersignal, insbesondere ab einem Zeitpunkt, in dem das Triggersignal einen vorgegebenen Pegel erreicht, überschreitet oder unterschreitet, während einer fest vorgegebenen Zeitdauer ermöglicht und andernfalls verhindert.

Advantageously, the control of the detection and / or analog-to-digital conversion of the at least one analog signal is performed using one of the following principles or a combination of these principles:

• The detection and / or the analog-to-digital conversion is triggered by the fact that the trigger signal reaches a predetermined level, exceeds or falls below.
• The detection and / or the analog-to-digital conversion is enabled as long as the trigger signal at least reaches and / or exceeds a predetermined signal level, otherwise the detection and / or analog-to-digital conversion is prevented.
• The detection and / or the analog-to-digital conversion is enabled as long as the trigger signal falls below and / or does not exceed a predetermined signal level, otherwise the detection and / or analog-to-digital conversion is prevented.
• The detection and / or the analog-to-digital conversion is possible with a periodic trigger signal during a predetermined number of periods and otherwise prevented.
• The detection and / or the analog-to-digital conversion is possible from a predetermined trigger signal, in particular from a point in time in which the trigger signal reaches a predetermined level, exceeds or falls below, allows for a fixed predetermined period of time and otherwise prevented.

Furthermore, in addition, the level of the at least one analog signal can be changed and / or a frequency filtering of the at least one analog signal can be performed. Furthermore, at least one control signal for controlling an internal combustion engine can be calculated from the at least one digital signal by means of a data processing algorithm.

Advantageously, the at least one electronic trigger signal can be frequency-multiplied by a predetermined multiplier and / or phase-shifted by a predetermined phase and / or at least one second electronic signal can be generated from the at least one electronic trigger signal Trigger signal are generated, wherein the second electronic trigger signal is a function with variable parameters of the first electronic trigger signal.

In particular, the generation of the at least one electronic trigger signal may be dependent on the rotational speed of the crankshaft. Advantageously, if the electronic trigger signal is periodic with a frequency F or approximately periodic or at least approximately periodic within a period considered, its frequency F multiplied with increasing speed such that the ratio between the frequency F and the rotational speed D itself decreases with increasing speed D.

Fig. 1

eine erste Ausführungsform eines Motorsteuerungsge- räts mit kurbelwellensynchron getriggertem Mikrocom- puter zur Messdatenerfassung;

Fig. 2

einen Verlauf eines Kurbelwellensignals;

Fig. 3

einen Verlauf eines Triggersignals;

Fig. 4

einen Ablaufplan eines ersten Ausführungsbeispiels eines Verfahrens zur kurbelwellensynchronen Messda- tenerfassung;

Fig. 5

einen Ablaufplan eines zweiten Ausführungsbeispiels eines Verfahrens zur kurbelwellensynchronen Messda- tenerfassung; und

Fig. 6

eine zweite Ausführungsform eines Motorsteuerungsge- räts mit kurbelwellensynchron getriggertem externen AD-Wandler zur Messdatenerfassung.

In the following, the invention will be explained in more detail with reference to exemplary embodiments, which are shown schematically in the figures. However, the invention is not limited to the examples. The same reference numerals in the individual figures designate the same or functionally identical or with respect to their functions corresponding elements. In detail shows:

Fig. 1

a first embodiment of a motor control device with crankshaft synchronously triggered microcomputer for measuring data acquisition;

Fig. 2

a course of a crankshaft signal;

Fig. 3

a course of a trigger signal;

Fig. 4

a flowchart of a first embodiment of a method for crankshaft synchronous measured data acquisition;

Fig. 5

a flowchart of a second embodiment of a method for crankshaft synchronous Messdaten ten detection; and

Fig. 6

a second embodiment of a Motorsteuerungsge- device with crankshaft synchronously triggered external AD converter for measuring data acquisition.

Core element of the engine control unit 110 in Fig. 1 is an integrated circuit (ASIC) 112 that includes a trigger converter 114 and a fast AD converter (FADC) 116. In the example shown, the ASIC 112 is a controller of the TC17xx family of the manufacturer Infineon. A signal output 118 of the trigger converter 114 is connected to a trigger input 120 of the FADC 116.

A crankshaft sensor 122 is connected via a crankshaft AD converter 124 to a signal input 126 of the trigger converter 114. A temperature sensor 128 is connected via a filter-amplifier unit 130 to a signal input 132 of the FADC 116.

To explain the interaction of the individual components of the engine control unit 110 in Fig. 1 is the crankshaft signal 134 in between the crankshaft A / D converter 124 and the trigger converter 112 Fig. 2 shown. Accordingly, the trigger signal 136 interchanged between the trigger converter 112 and the FADC 116 is in Fig. 3 shown.

First, as described above, the crankshaft sensor 122 detects a signal of the crankshaft, which in this example is an analog sine signal (not shown) of a magnetic sensor that detects the position of the teeth of the above-described toothed disk. This analog sine signal is in the crankshaft AD converter 124 in the in Fig. 2 converted crankshaft signal 134 converted. This is a square wave signal which is at "Low" level (here the zero line) for a period t1 to t2, and then at a TTL level "High" (5 Volt) for a period from t2 to t3. , The signal thus has a period t3-t1 and a frequency of 1 / (t3-t1).

The crankshaft signal 134 is frequency multiplied by a factor of nine in the trigger converter 114 in this simple example. Accordingly, the trigger converter 114 generates from the crankshaft signal 134 as a trigger signal 136 a square wave signal having the frequency 9x1 / (t3-t1). The signal levels are left unchanged in this example. The trigger converter 114 starts the conversion at the time t1, that is, with the falling edge of the crankshaft signal 134 and generates a rising edge of the trigger signal 136. Accordingly, the trigger signal 136 is 180 ° out of phase with the crankshaft signal 134.

This trigger signal 136 is forwarded via the signal input 120 to the FADC 116. The trigger input 120 is configured such that the FADC 116 accepts only signals at its signal input 132 when the trigger signal 136 exceeds a predetermined level. In the remaining time, the FADC 116 "ignores" signals at its signal input 132.

By means of in Fig. 1 described structure can be, for example, in Fig. 4 perform the procedure shown. First, in step 410, as described above, the signal of the crankshaft is detected, digitized in the crankshaft AD converter 124 and then converted into the trigger signal 136 in the trigger converter 112 in step 412. This is then forwarded in step 414 to an analog-to-digital converter, here specifically the FADC 116. The FADC 116 queries in step 416 if the trigger signal exceeds a predetermined value. This query can be done in a permanent loop. Only if this is the case, in step 418, an analog signal, which in the in Fig. 1 is passed from the filter-amplifier unit 130 to the FADC 116, and converted to a digital signal in step 420. Complete or partial preprocessing of the signal (see above) can also be carried out in this step. This digital signal again, then in step 422, for further processing, to a (in Fig. 1 not shown) microprocessor forwarded, which can generate control signals for motor control from this signal according to its programmed algorithms, for example.

In Fig. 5 an analog method is shown in which the trigger signal 136 is not used to trigger an AD converter, but to trigger the data acquisition by a microprocessor. This microprocessor, which is part of virtually every engine control device, is in Fig. 1 not shown. It can be another component of the ASICS 112.

Analogous to Fig. 4 the angular position of the crankshaft is first detected in step 510 and converted into a trigger signal in step 512.

This trigger signal is then forwarded in step 514 not directly to an A / D converter, but to a microprocessor. This queries in step 516, the trigger signal and does not accept data from the AD converter, as long as it does not exceed a predetermined level (step 518). Regardless, an AD converter continuously acquires analog measurement data from one or more sensors in step 520, possibly pre-processing, converts the analog signals into digital signals, and provides the converted signals to the microprocessor. However, only if the query determines a sufficient trigger level in step 516 does the microprocessor accept this data in step 522 and further process it in step 524.

In Fig. 6 is one too Fig. 1 shown in an alternative structure of a motor control device 110, in which the crankshaft synchronous trigger signal 136 is not used to trigger an internal FADC 116, but to trigger an external AD converter 610. The main difference of the Building in Fig. 6 is that the signal output 118 of the trigger converter 114 is connected to a trigger input 612 of the external AD converter 610. This in turn is connected via an interface 614 to a microprocessor 616 integrated in the ASIC 112.

The functioning of the in Fig. 6 shown construction corresponds to the structure in Fig. 1 , However, the AD conversion of the analog signal generated by the sensor 128 does not take place in the ASIC 112 but by the external electronic component 610. A preprocessing of the analog or already digitized data can also take place in the external AD converter 610 so that the signals transmitted via the Interface 614 to the microprocessor 616 transmitted data can already be reduced to an absolute minimum. This further relieves the microprocessor 610. Since the external AD converter 610 is easily accessible, this can also be easily replaced and replaced, for example, with the availability of more modern components.

This in Fig. 4 The method described and described above can be applied to the in Fig. 6 shown arrangement to be transmitted. The forwarding of the trigger signal 136 to an AD converter in step 414 takes place in this case via an external line connection.

Claims (13)

1. Engine control unit (110) having

   - a microprocessor (616) for the program-controlled calculation of engine control signals based on at least one analogue signal, in particular an analogue sensor signal,

   - means (128, 130, 116; 610) to detect the analogue signal, having a signal input (132) for the analogue signal and an analogue/digital converter (116;610) for converting the analogue signal into at least one digital signal, which is fed to the microprocessor (616) for its calculation of the engine control signals,

   - means (122, 124) to detect an angle position of a crankshaft, and

   - means (114) to convert the angle position of the crankshaft into an electronic trigger signal (136); characterised in that

   - the means (114) to convert the angle position of the crankshaft into an electronic trigger signal (136) operate independently of the program flow in the microprocessor (616), and

   - that the means (128, 130, 116; 610) to detect the analogue signal also have a control facility (120; 612) which operates independently of the program flow in the microprocessor (616), said control facility starting and/or terminating the detection of the analogue signal and/or the analogue/digital conversion of the analogue signal as a function of the electronic trigger signal (126), in order to temporarily relieve the microprocessor (616) within each engine operating cycle.
2. Engine control unit (110) according to claim 1, characterised in that
   the means (128, 130, 116; 610) to detect the analogue signal also have at least one of the following components:

   - means (130;610) to adapt or modify the signal level of the analogue signal,

   - means (130;610) for frequency filtering of the analogue signal.
3. Engine control unit (110) according to one of the preceding claims,
   characterised in that
   the control facility has a trigger input connected to the data processing device (616).
4. Engine control unit (110) according to one of the preceding claims,
   characterised in that
   the analogue/digital converter (116; 610) comprises at least one of the following means to pre-process the digital signals:

   - means for statistical analysis of the digital signals,

   - means to form a temporal mean value,

   - means to adapt and supply an analytical approximation function to the digital signals.
5. Engine control unit (110) according to one of the preceding claims,
   characterised in that
   the means (114) to convert the angle position of the crankshaft into an electronic trigger signal (136) comprise one or more of the following components:

   - means to adapt or modify a signal level,

   - means for frequency multiplication and/or phase displacement of a periodic signal,

   - means for frequency filtering of a periodic signal,

   - a counting device to count periods or sub-periods of a periodic signal,

   - means to select predetermined periods of a periodic signal.
6. Engine control unit (110) according to one of the preceding claims,
   characterised in that
   the control facility (114, 120; 612) comprises a trigger input (120; 612) connected to the analogue/digital converter (116; 610).
7. Engine control unit (110) according to one of the preceding claims,
   characterised in that
   the following components are integrated wholly or partially into an integrated electronic circuit (ASIC) (112):

   - the means (114) to convert the angle position of the crankshaft into an electronic trigger signal, and

   - the means (116) to detect the analogue signal (116).
8. Method to control the engine, having the following steps:

   - program-controlled calculation of engine control signals based on at least one analogue signal, in particular an analogue sensor signal, by means of a microprocessor (616),

   - detection and analogue/digital conversion of the analogue signal to convert the analogue signal into at least one digital signal, which is fed to the microprocessor (616) for its calculation of the engine control signals,

   - detection of an angle position of a crankshaft, and

   - conversion of the angle position of the crankshaft into an electronic trigger signal (136),
   characterised in that
   the conversion of the angle position of the crank shaft into the electronic trigger signal (136) takes place independently of the program flow in the microprocessor (616), and
   the detection of the analogue signal also includes a control which takes place independently of the program flow in the microprocessor (616), said control starting and/or terminating the detection of the analogue signal and/or the analogue/digital conversion of the analogue signal as a function of the electronic trigger signal, in order to temporarily relieve the microprocessor (616) within each engine operating cycle.
9. Method according to claim 8, characterised in that the detection and analogue/digital conversion of the analogue signal comprises one or more of the following sub-steps:

   - the detection and/or analogue/digital conversion is initiated when the trigger signal (136) reaches, exceeds or drops below a predetermined level,

   - the detection and/or analogue/digital conversion is/are allowed, as long as the trigger signal (136) at least reaches and/or exceeds a predetermined signal level, with the detection and/or analogue/digital conversion otherwise being prevented,

   - the detection and/or analogue/digital conversion is/are allowed, as long as the trigger signal (136) is below and/or does not exceed a predetermined signal level, with the detection and/or analogue/digital conversion otherwise being prevented,

   - the detection and/or analogue/digital conversion is/are allowed in the case of a periodic trigger signal (136) during a predetermined number of periods and otherwise prevented,

   - the detection and/or analogue/digital conversion is/are allowed from a predetermined trigger signal (136), in particular from a time when the trigger signal (136) reaches, exceeds or drops below a predetermined level, during a permanently predetermined time period, and otherwise prevented.
10. Method according to one of the preceding method claims, characterised in that
    the detection of the analogue signal also comprises one or more of the following sub steps:

    - the level of the analogue signal is modified,

    - a frequency filtering of the analogue signal is carried out,

    - at least one control signal is calculated from the at least one digital signal by means of a data processing algorithm, to regulate an internal combustion engine.
11. Method according to one of the preceding method claims, characterised in that
    the conversion of the angle position of the crankshaft into the electronic trigger signal (136) also comprises one or more of the following sub-steps:

    - the at least one electronic trigger signal (136) is frequency-multiplied by a predetermined multiplier,

    - the at least one electronic trigger signal (136) is phase-displaced by a predetermined phase,

    - at least one second electronic trigger signal (136) is generated from the at least one electronic trigger signal (134),

    with the second electronic trigger signal (136) being a function with changeable parameters of the first electronic trigger signal (134).
12. Method according to one of the preceding method claims, characterised in that
    the generation of the at least one electronic trigger signal (136) in step b) is a function of the rotation speed of the crankshaft.
13. Method according to the preceding claim,
    characterised in that
    the electronic trigger signal (136) is periodic with a frequency F,
    with the relationship between the frequency F and the rotation speed D decreasing as the rotation speed D increases.

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