EP0325960A2 - Electronic control device for motor vehicles - Google Patents

Abstract

An electronic control device for motor vehicles comprises a central processing unit, a program memory, a data memory and an input/output unit with a plurality of input and output channels. The basic design which can be configured simultaneously for a plurality of different individual variant embodiments is assigned a code memory (52) for at least one code word for determining the respective individual variant embodiment. The respective program sections, data sets, input and/or output channels are driveable as a function of the respective contents of the code memory (52). <IMAGE>

Description

The invention relates to an electronic control unit for motor vehicles, the basic equipment of which in particular comprises a central unit, a program memory, a data memory and an input / output unit with a plurality of input and output channels.

Electronic control systems of motor vehicles are used in practice to perform a wide variety of different tasks, and depending on the vehicle type, drive unit and basic and additional equipment or units, only a certain combination of all possible areas of activity is required to cover the individual motor vehicle embodiment variant.

Different sensors and actuators usually require different input and output circuits in the control unit hardware.

To meet the different requirements and adaptations with the same control unit hardware, it is customary to provide specific software consisting of a specific program and / or a specific data set for each tuning and / or function variant or motor vehicle embodiment variant.

In practice, the adaptation of such an electronic control system to the individual motor vehicle design variant leads to a large number of control unit design variants.

Warehousing and handling in production and customer service are correspondingly complicated.

The invention has for its object to provide an electronic control unit of the type mentioned that Probably in production as well as in service, as many different design variants of motor vehicles as possible can be adapted quickly and reliably in a simple manner.

The object is achieved according to the invention in that a code memory for at least one code word for determining the respective individual embodiment variant is assigned to the basic equipment which can be designed simultaneously for several different individual embodiment variants, and in that the associated program sections, data records, input and / or output channels as a function of the respective contents of the code memory can be controlled. The input and / or output channels can be implemented, for example, by special circuits.

On the basis of this design, the electronic control device can have a uniform hardware, a uniform program and / or uniform data records for all different design variants that are appropriately equipped. Additional, space-consuming components are not required for an expansion of the functions or input / output circuits that may be required.

An expansion of the design variants and adaptation to the equipment level of the vehicle in question is possible at short notice, since only the relevant code word has to be changed. In this work there are no special assembly times. In particular, even the simplest programming devices that are suitable even for smaller workshops are sufficient. With the use of the code word mentioned, the possibility is also created in a particularly advantageous manner, in particular to read this code word into a diagnostic system, for example, and with one and to carry out program branches in a respective test program with the same code word.

Furthermore, since only one code word may have to be changed, the customer service generally performed in motor vehicle workshops is completely unproblematic.

Due to the fact that only very little data has to be programmed or reprogrammed in the workshop in question, the risk of transmission errors is practically excluded. It is generally sufficient to reprogram the code word, which can usually consist of a single byte.

With the code word used, for example, different logic values of the binary digits each define different function and / or coordination variants. The following possible combinations would be conceivable, for example:

The first bit 0 alternatively controls a load control via an absolute pressure sensor or a load control via a load signal from the air quantity meter of the injection system. The second bit 1 of the code word alternatively activates an idling control with a speed and load-dependent idling characteristic or an idling control with an idling contact selection. Bit 2 of the code word determines whether a fuel cut-off control should preferably be activated with an ignition angle change limitation or not. Bit 3 of the code word provides an alternative choice between an ignition control with two maps (16 x 16) with load gradient-dependent switching and an ignition control with a map (32 x 16) with an assigned idling characteristic. Bit 4 determines whether control with gearbox intervention or without gearbox intervention should take place. With a logic level 1 of bit 5 is a function variant with electronic Ab gas recirculation can be activated. The code word bit 6 determines whether or not a dynamic adaptation is carried out. Finally, the last bit 7 of the code word can indicate whether a Hall release or an inductive crankshaft release is used to determine the speed. In the example described, the remaining functions are always activated regardless of the respective code word.

In terms of hardware, the control units can be equipped for several, but only for a part of the overall possible design variants. With such an assembly, for example, the design variants are taken into account that roll off the assembly line in the relevant production line. The control units supplied to the conveyor can either be on the conveyor - i.e. near the belt, but regardless of the cycle time - can be programmed with the possible data records. However, they can also be delivered ready-programmed.

At the time of installation in the vehicle or later, the code word specific to the vehicle version is entered into the code memory in order to control or release the appropriate special control unit version.

Such hardware partial assembly allows in particular an optimal compromise between the resulting cost and a simple type of installation. This reduces the risk of confusion and enables fast programming in the cycle time.

According to a further embodiment variant, the code word used can generate the following ignition system, for example:
- Load detection via a pressure sensor
- Speed detection via a Hall sensor
- Two ignition angle maps, for example, for two fuel qualities that can be selected from the outside
- Thrust cut-out control
- No exhaust gas recirculation control
- No electrical intake manifold heating
- Record number 2 active
- Idling characteristic integrated in the map.

However, a full assembly, i.e. the control unit can be equipped for all of the design variants provided.

This variant is particularly suitable for customer service as a replacement control unit or for test purposes, since only one control unit is required or has to be kept in stock with which all possible or all vehicle design variants in the field can be serviced. This is of particular advantage in the case of exotic country variants.

The software, i.e. the program and / or the data is either provided for all design variants or, if the amount of data should become too extensive, put together in meaningful variant packages and made available as a component for subsequent installation. There is practically no restriction on the size of the data record.

In the workshop, only the special code memory has to be loaded or an additional module or variant package has to be inserted. The loading of the special code memory or the writing of the desired code word or the desired code words can be carried out with the simplest programming devices.

Since little programming is required, the sources of error are also low.

It is also advantageous that the programs and data records, which comprise a number of different design variants, can be stored in ROM memories which are less expensive than reversible EEPROM memory locations. Regardless of the scope of the program in question and the data records in question, the programming time required by customer service remains the same and extremely short, since only the code word has to be changed accordingly.

Finally, there is also better protection against transmission errors of the control programs and data sets, since only complete data sets and program combinations can be selected via the code byte (s).

The code memory which holds the code word is advantageously assigned to the data memory and preferably integrated therein. The code word is expediently part of the band-end programmable data. A division of the tape programming can also be provided. In these preferred embodiments, no additional connections in the plug are required. There are no additional cables. No additional plugs and / or jumpers are required.

The codeword recorded in the code memory preferably comprises a plurality of binary digits, different logic values of the binary digits each defining different individual design variants. Accordingly, a kind of yes-no decision can be made in each bit in order to activate one program section or the other depending on it, or to selectively control a relevant program section or not. The same applies to the data records and the Basic equipment input / output channels.

The code memory can be part of an internal memory of an intelligent component, e.g. of a microcontroller. A PROM (Programmable Read Only Memory), an E-PROM (Erasable ROM) or an EE-PROM (Electrical Erasable PROM) can be provided as the internal memory.

The code memory can also form part of an external memory. The external memory can be a memory module outside the intelligent module, e.g. Microprocessor or controller, but are still present in the control unit as PROM, E-PROM or EE-PROM. This external memory can also include the program and / or data memory.

There is also a special memory in the control unit, e.g. a code PROM or a code EE PROM possible.

The code memory can also be outside the control unit housing.

According to a further particularly advantageous embodiment variant, the basic equipment comprises a diagnosis and / or tester connection. The basic equipment can expediently also include an output of the code word to an electronic test system.

The code word can accordingly be read out by an electrical test and / or test system and in turn can then be used in this to control or to compile test programs. As a result, a uniform test program for different design variants can also be implemented in such a test and / or test system, which leads to a significant simplification of the check and a reduction in the sources of errors in service.

Further advantageous embodiments of the invention are specified in the subclaims.

• Fig. 1 eine schematische Darstellung eines elektroni­schen Steuergeräts mit zugeordneten Eingangs- und Ausgangskanälen,
• Fig. 2 ein Blockdiagramm des einen Codespeicher auf­weisenden elektronischen Steuergeräts,
• Fig. 3 ein Flußdiagramm mit Programmschritten zur vom Codewort abhängigen Leerlauf-Kennlinienan­wahl,
• Fig. 4 ein Flußdiagramm mit Programmschritten zur vom Codewort abhängigen Kennfeldanwahl, und
• Fig. 5a - 5i ein Flußdiagramm der bei einer anderen Ausfüh­rungsvariante des Steuergeräts in Abhängig­keit vom Codewort durchgeführten Programm­schritte.

The invention is explained below using exemplary embodiments with reference to the drawing; in this shows:

• 1 is a schematic representation of an electronic control unit with assigned input and output channels,
• 2 is a block diagram of the electronic control unit having a code memory,
• 3 shows a flow chart with program steps for the idle characteristic curve selection dependent on the code word,
• Fig. 4 is a flowchart with program steps for the map word dependent map selection, and
• 5a-5i show a flowchart of the program steps carried out in another embodiment variant of the control device as a function of the code word.

1 schematically shows an electronic control device 10, which is provided in particular for motor vehicles and to which input channels 12-30 and output channels 32-44 are assigned.

These input or input and output or output channels are implemented by at least one input / output unit 58 of the electronic motor vehicle control unit 10 can be enabled or activated depending on a code word recorded in a code memory 52 (FIG. 2).

The input channels 12-30 realized by the input / output unit 58 are assigned, inter alia, a plurality of detectors or sensors 60 which access the input / output unit 58 of the electronic control unit 10 either directly or via corresponding converters 62.

On the other hand, the output channels 32-44 can in particular be assigned actuators 66 which are connected either via output stages 64 or directly to the input / output unit 58.

Input signals supplied to the input / output unit 58 can originate, for example, from a crank angle sensor, air mass sensor, engine temperature sensor, an ignition switch, gear selector switch and also an input unit. On the output side, for example, a throttle valve actuator, idle air mass actuator, an injection valve, a distributor, an exhaust gas recirculation actuator, transmission actuators, voltage source relays, an output data display unit, an output and / or input unit and also communication channels from and / or be provided to other control units.

The input signals supplied to the electronic control unit 10 are used to control various functional sequences in the internal combustion engine, such as, for example, the metering of fuel, the idle air quantity, the ignition timing and the like.

As can be seen in FIG. 2, the input / output unit 58 is connected via a system bus 56 to a central unit 46 of the electronic control unit 10 connected.

The system bus 56 is also assigned a program memory 48, a data memory 50 and the code memory 52 which is used to hold at least one code word. A clock 54 supplies the central unit 46 with the required clock pulses.

The basic configuration of the electronic motor vehicle control unit, which includes the central unit 46, the system bus 56, the input / output unit 58, the clock generator 54, the program memory 48 and the data memory 50, is simultaneously designed for several different individual design variants.

In the present example, a code word consisting of a code byte is stored in the code memory 52 and determines the respective individual embodiment variant. The program sections, data sets, input and / or output channels 12 - 30; 32-44 can be activated or controlled depending on the code word contained in the code memory 52.

In this basic configuration of the electronic control unit 10, different hardware versions such as, for example, different assembly variants can also be taken into account. The required coordination of the embodiment variant with an implemented hardware configuration also takes place via the code word contained in the code memory 52.

The program memory 48 contains a standard program with a number of subroutines which, or their combination, are activated by an appropriate code word.

The electronic control device 10 can be designed as a tape end-programmable device, the code memory 52 preferably representing part of the tape end-programmable storage units.

The code memory 52 can in particular be assigned to the data memory 50 and can be integrated therein.

In the exemplary embodiment described, the design or tuning variants which can be determined by the code word include in particular the ignition control, a fuel cut-off, self-diagnosis, a PTC (positive temperature coefficient) control and an electronic exhaust gas recirculation.

For this purpose, a Hall speed sensor is assigned to the input channel 12 of the electronic control device 10 and an inductive speed sensor is assigned to the input channel 14. In the case of the function variant implemented in each case, only one of the two sensors is generally provided, the corresponding coordination being carried out via the assigned code word.

The Hall speed sensor is, for example, a speed sensor provided in the ignition distributor. In contrast, the inductive speed sensor will be provided in the area of the crankshaft.

Furthermore, an oil temperature sensor is assigned to the input channel 16 of the control device 10, and an octane number plug is assigned to the input channel 18. Such an octane number connector makes it possible, for example, to adjust the octane number via external resistors or two resistors and a second code byte for such an octane number adjustment in at least eight stages using at least eight characteristic curves.

The input channel 20 is provided for a pressure sensor, which in particular can be an absolute pressure sensor for load detection.

A channel for an air mass flow meter can also be provided. Input channel 28 is a digital load input for load detection in an injection variant. Instead, a communication channel can also be provided in order to receive load information from an injection system.

The input channel 22 is intended for a digital coding plug.

The input channel 24 is assigned two switches that can be connected to ground for idling / full-load signaling.

The input channel 26 is a transmission input for receiving signals from the transmission (here from the electronic control unit)

Finally, the input channel 30 is assigned to a diagnostic line or diagnostic stimulus line.

The output channels 32-44 of the electronic control unit 10 deliver a speed signal, ignition signal, fuel cut-off signal, exhaust gas recirculation signal and a PTC (positive temperature coefficient) signal in the exemplary embodiment described, while the output channel 44 is assigned to a bidirectional diagnostic line (input / output) is.
These output signals can at least partially act on actuators 66.

The code word that can be written into the code memory 52 is shown as a code byte with 8 bits, with different logic values of the binary digits define different function and / or coordination variants. Depending on the logic values of these bits, the corresponding input channels 12-30 and / or output channels 32-44, program parts and / or data records are activated.

Thus, the first bit 0 of the code byte or code word contained in the code memory 52 alternatively controls a load control via an absolute pressure sensor or a load control via a load signal from the air quantity meter of the injection system.

The second bit 1 of the code word alternatively activates an idling control with a speed-dependent and load-dependent idling characteristic or an idling control with an idling characteristic contact selection.

Bit 2 of the code word determines whether or not a fuel cut-off control should preferably be activated with an ignition angle change limitation.

Bit 3 of the code word provides an alternative choice between an ignition control with two maps (16 x 16) with load gradient-dependent switching and an ignition control with a map (32 x 16) with an assigned idling characteristic.

Bit 4 of the code word contained in the code memory 52 determines whether control with transmission intervention (logic level 1) or without transmission intervention should take place.

A function variant with electronic exhaust gas recirculation can be activated with a logic level 1 of bit 5 of the code word.

The code word bit 6 determines whether or not a dynamic adaptation is carried out.

The last bit 7 of the code word finally indicates whether a Hall release or an inductive crankshaft release is used to determine the speed.

In the present exemplary embodiment, the remaining functions are always activated regardless of the respective code word.

3 shows individual program steps carried out by the electronic control unit 10 for the selection of the idle characteristic curve.

After starting the motor vehicle in question, code word bit 1 is first queried. If this bit has a logic level 0, a check is first carried out to determine whether the required idling condition is fulfilled. If this is the case, a speed and load-dependent idling characteristic is selected. Otherwise there is a transition to another part of the program.

If it turns out that code word bit 1 has logic level 1, code word bit 3 is checked. In any case, the idle condition is first checked in order to switch to another part of the program if necessary. Otherwise, if there is a logic level 1 for the code word bit 3, a contact-controlled idling characteristic is driven without switching. If this logic level is 0, a temperature changeover takes place between two contact-controlled idling characteristics 1 and 2. The selection of one or the other idling characteristic is made depending on the oil temperature.

The program loop finally leads back to the start in order to query code word bit 1 again.

4 shows individual program steps of the electronic control device 10 for the map selection.

After the start, a check is first carried out to determine whether the map condition is met. If this is not the case, another part of the program is accessed.

Otherwise, code word bit 3 is checked. If this code word bit 3 has logic level 1, a map (32 x 16) is activated without switching.

If, on the other hand, the logic level of this code word bit 3 is 0, a load gradient-dependent switchover between two characteristic maps 1 and 2 takes place. The relevant characteristic map is selected as a function of the pressure difference or load signal difference.

Finally, the program loop leads back to the start in order to check the presence of the map condition again.

5a to 5i show a flowchart of the program steps carried out in a further embodiment variant of the control unit as a function of a code word in question.

According to this embodiment variant, an ignition system should be given the following functional scope and be usable for the following embodiment variants.

Features:

- Map ignition angle control (depending on engine speed, load and temperature), where the engine speed and load detection can be carried out using two different principles, e.g. Hall-inductive engine speed detection or vacuum / digital load detection.
- The ignition angle should be controlled either via a map or two externally selectable maps, for example for two alternative fuels.
- The following functions should also be controllable:
- fuel cut-off
- exhaust gas recirculation
- electrical intake pipe preheating.

In addition, for example, several, in the present exemplary embodiment two, voting variants (data records) can be optionally selected.

The control unit is equipped with self-diagnosis.

The binary positions of the control byte have the following meaning:

Bit 0

State 0: load detection via pressure sensor
State 1: Load detection digital signal

Bit 1

State 0: Hall sensor speed detection
State 1: Speed detection of inductive sensor

Bit 2

State 0: an ignition angle map
State 1: two ignition angle maps, selectable externally

Bit 3

State 0: Thrust cutout active
State 1: no fuel cut-off

Bit 4

State 0: exhaust gas recirculation active
State 1: no exhaust gas recirculation

Bit 5

State 0: electrical intake manifold preheating active
Condition 1: no electrical intake pipe preheating

Bit 6:

State 0: LL characteristic curve integrated in the map
State 1: LL characteristics contact selection

Bit 7:

State 0: Data record 1 active
State 1: Data record 2 active.

The second variant of the control unit is designed for all possible software and hardware versions. The data record and the functions for the desired design variant are in turn activated via the control byte (s).

In the specific case, the control byte used has the following structure: Bit: 7 6 5 4th 3rd 2nd 1 0 Status: 1 0 1 1 0 1 0 0

The flowchart shown in FIGS. 5a to 5i shows the individual program steps which are characteristic of the present exemplary embodiment, the paths marked with a double arrow corresponding to the program sequence the specified control byte. Up to interface 5, the query is made once when the engine is started.

As can be seen from the flow chart according to FIGS. 5a to 5i, the code byte or code word used generates the following ignition system:
- Load detection via a pressure sensor
- Speed detection via a Hall sensor
- Two ignition angle maps, for example, for two fuel qualities that can be selected from the outside
- Thrust cut-out control
- No exhaust gas recirculation control
- No electrical intake manifold heating
- Record number 2 active
- Idling characteristic integrated in the map.

Claims (22)

1. Electronic control unit for motor vehicles, the basic equipment of which in particular comprises a central unit, a program memory, a data memory and an input / output unit with a plurality of input and output channels,
characterized by
that a code memory (52) for at least one code word for determining the respective individual embodiment variant is assigned to the basic equipment which can be designed simultaneously for several different individual embodiment variants and that the associated program sections, data records, input and / or output channels (12-30; 32-44) can be controlled as a function of the respective content of the code memory (52). 2. Electronic control device according to claim 1,
characterized in that the basic equipment comprising the central unit, the program memory (48), the data memory (50) and the input / output unit (58) are coordinated with different hardware versions and can be controlled by the code word of the code memory (52). Voting variants included. 3 electronic control device according to claim 1 or 2,
characterized in that the program memory (48) is designed to hold a standard program with a plurality of program branches and / or subroutines and the program branches and / or the respective subroutine or the respective subroutine combination can be controlled or activated by the code word of the code memory (52). 4. Electronic control device according to one of the preceding claims,
characterized in that the code memory (52) receiving the code word is assigned to the data memory (50) and is preferably integrated therein. 5. Electronic control device according to one of the preceding claims,
characterized in that the code memory (52) is an internal memory. 6. Electronic control device according to one of the preceding claims,
characterized in that the code memory (52) is an external memory. 7. Electronic control device according to one of the preceding claims,
characterized in that the code memory (52) is arranged outside the control unit housing. 8. Electronic control device according to one of the preceding claims,
characterized in that the code memory (52) is an irreversible memory such as, in particular, a PROM memory. 9. Electronic control device according to one of the preceding claims,
characterized in that the code memory (52) is a reversible memory such as, in particular, an E-PROM memory (Erasable Prom) or an EE-PROM memory (Electrical Erasable Prom). 10. Electronic control device according to one of the preceding claims,
characterized in that the code word recorded in the code memory (52) comprises a plurality of binary positions and different logic values of the binary positions each define different individual design variants. 11. Electronic control device according to one of the preceding claims,
characterized in that the code memory (52) is designed as a code plug or code switch. 12. Electronic control device according to one of the preceding claims,
characterized in that an external code plug or code switch is provided. 13. Electronic control device according to one of the preceding claims,
characterized in that the basic equipment comprises, as an alternative to the embodiment of the code word of the code memory (52), a load control via an absolute pressure sensor (20) and a load control via part load / full load characteristics. 14. Electronic control device according to one of the preceding claims,
characterized in that the basic equipment, as an alternative embodiment variant which can be controlled by the code word of the code memory (52), comprises a speed-dependent and load-dependent idling control and a contact selection of the idling characteristic. 15. Electronic control device according to one of the preceding claims,
characterized in that the basic configuration, as an individual embodiment variant which can be optionally controlled by the code word of the code memory (52), comprises a fuel cut-off control, preferably with a limitation of the ignition angle. 16. Electronic control device according to one of the preceding claims,
characterized in that the basic equipment as an alternative design variant which can be controlled alternatively by the code word of the code memory (52) ten comprises an ignition control with two maps with switching and an ignition control with a map with an associated idling characteristic. 17. Electronic control device according to one of the preceding claims,
characterized in that the basic equipment, as an individual embodiment variant which can optionally be controlled by the code word, comprises a control with gear intervention. 18. Electronic control device according to one of the preceding claims,
characterized in that the basic equipment comprises an individual exhaust gas recirculation as an individual embodiment variant which can be optionally controlled by the code word of the code memory (52). 19. Electronic control device according to one of the preceding claims,
characterized in that the basic configuration, as an individual embodiment variant which can be optionally controlled by the code word of the code memory (52), comprises a controller with a dynamic adaptation. 20. Electronic control device according to one of the preceding claims,
characterized in that the basic equipment comprises a Hall speed sensor (l2) and / or an inductive speed sensor (l4) and that these sensors (12, 14) can alternatively be controlled by the code word of the code memory (52). 21. Electronic control device according to one of the preceding claims,
characterized in that the basic equipment includes a diagnostic and / or tester connection. 22. Electronic control device according to one of the preceding claims,
characterized in that the basic equipment comprises an output of the code word to an electronic test system.

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