DE3105856A1 - Method and device for adapting stored characteristic variables in electronic control devices, in particular for internal combustion engines - Google Patents

Description

9.2.1981 Ve / Hm

ROBERT BOSCH GMBH, 7OOO STUTTGART 1

Method and device for adapting stored parameters in electronic control devices, in particular for internal combustion engines

State of the art

The invention is based on a method and a device for adapting stored parameters in Electronic control devices for systems or machines, in particular internal combustion engines, according to the class of Main claim. Especially with an ignition and Injection control for internal combustion engines by one The characteristic curves and maps on a test internal combustion engine are usually theoretically used in a microprocessor and finally adapted empirically by measuring operating parameters until optimal running properties are achieved with favorable exhaust gas values and low consumption. The parameters obtained in this way are then fixed in the form of maps in read-only memories (ROM) and determine the control behavior

in the same way for all internal combustion engines this Type. Care must be taken here because of the unavoidable manufacturing tolerances of encoders and additional units ensure that a sufficient distance from critical limit values is maintained. Such critical values set e.g. the knock limit or statutory exhaust values Although a characteristic curve close to these limit values would be desirable in principle, must be due to a sufficient distance must be maintained between these manufacturing tolerances. Other reasons that none are optimal possible parameters can be used, there is the risk of aging of individual components as well as environmental influences. Since internal combustion engines and other systems are usually used in a wide variety of climatic conditions, which prevail in the various countries must work, a compromise must be made in the choice of the parameters can be found which naturally prevents an optimal choice for a certain combination of environmental conditions .

Regardless of environmental conditions or aging, control systems for ignition or injection, such as are known from DE-OS 27 39 508 and 30 09 0k6, for example . These systems have the disadvantage that complex additional systems such as superordinate control systems for starting and emergency operation as well as additional, expensive sensors are required in every vehicle.

Advantages of the invention

The inventive method with the characterizing Features of the main claim as well as the corresponding In contrast, devices have the advantage that the stored identifiers that are decisive for optimal operation

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sizes subsequently optimized with regard to manufacturing tolerances and adapted to specific environmental conditions ". This can be done, for example, by the fact that the respective system after its production and initial Basic equipment with parameters are exposed to the environmental conditions in which they will work later target. There these parameters are adapted according to the method according to the invention. E.g. in an internal combustion engine the entire vehicle can be exported to the country of destination and under the local environmental conditions (certain fuel quality, climatic conditions, Emission regulations etc.). A uniform control device can therefore be used under a wide variety of Working conditions optimally. This adaptation can also be repeated at certain time intervals (e.g. customer service) in order to compensate for age-related changes. In contrast to the known control systems no complicated and expensive additional systems are required in the vehicle itself. These are only stored centrally in Production facilities and workshops are required in which the adaptation is to be carried out.

The measures listed in the subclaims are part of the development and improvement of the The method specified in the main claim is possible. Particularly advantageous and associated with low investment is the use of a central master computer for the adaptation, which is connected to a large number of terminals at the various Adaptation sites, in particular workshops, are assigned. This master computer can e.g. via telephone connections connected to the terminals. In this way, you can also subsequently, e.g. because of changed legal regulations - the maps also older

Systems can be changed without any effort. The manufacturer only needs to change the corresponding programs on the central control computer.

Furthermore, it is particularly advantageous and time-saving in the case of parameters stored in the form of characteristic curves and maps, only a few typical operating points as support points to adapt and then, depending on this adaptation, to interpolate the entire characteristic curves and maps.

drawing

An embodiment of the invention is shown in the drawing and in more detail in the following description explained. The single figure shows the exemplary embodiment in a block diagram.

Description of the embodiment

A control computer 10 for approaching the operating points is connected with corresponding control lines 11 to an internal combustion engine 12 which is controlled by an electronic control unit 13. This control device 13 can, for example, be a microcomputer for determining the ignition and fuel injection processes. A large number of transmitters (not shown in more detail) for operating variables are connected to the internal combustion engine, the signals of which are fed to a processing and selection circuit Ik. The selection process is determined by the control computer 10. The processed, parameter-dependent signals are compared in a comparison device 15 with the output values of a nominal operating variable generator 16. This generates the setpoints depending on control commands

of the control computer 10. The target values are determined on the basis of statutory provisions (e.g. for exhaust gas values), consumption values and engine power. Such a setpoint can, for example, also be a limit value, whereby the Actual value is to change until a signal indicating the limit value occurs. This is e.g. when scanning given the knock limit. The target / actual deviation is one Characteristic correction circuit 17 supplied, in the algorithms for adjusting the parameters, characteristics and Characteristic maps are stored as a function of the currently detected operating variable. The output of this parameter correction circuit 17 with the corrected parameters is fed to the electronic control unit 13.

In the figure shown, denotes the with an openwork Line delimited area 18 the area of the series system in which the data in the electronic control unit can be adapted. The other assemblies designate the permanently installed system for adaptation, which as a central investment at the manufacturer or in workshops.

The mode of operation of the arrangement shown is essentially that with the help of an arbitrarily selectable Program in the control computer 10 successively different characteristic operating points of the to be adapted System can be started up. In a motor vehicle are e.g. different speed values, different acceleration and deceleration values, different temperature ranges when the engine is warming up and, if necessary - with greater effort - different outside temperatures, External pressures, fuel-air compositions and load

conditions. The latter points can be set by the outputs 19 of the control computer 10, which in the case of a load act on a roller test stand, for example, or in the case of the outside temperature on the room heating. If such an operating point set _s so 12 different operating variables or parameters P are on the machine "or system measured, and the preparation and selection circuit ~ \ k supplied. Such parameters are for example the engine power, torque, pollutant emissions, fuel consumption, Uneven running and signals from a knock sensor. Depending on the set program in the control computer 10, different operating variables are now successively or simultaneously compared with preset setpoints of the setpoint operating variable generator. The deviation is evaluated in the parameter correction circuit 17 within the framework of defined algorithms. These can be simple additions or multiplications The parameter changed in this way is used as a basis for further operation in the electronic control unit 13. Since the described arrangement represents a control loop, the parameter is changed until either the actual value ert is equal to the setpoint or - if a limit value is specified - the limit value has been reached. In the case of setting the knock limit, for example, this means that the characteristic variable responsible for the ignition point is changed in the direction of advance until a knock signal occurs or just does not occur. Correspondingly, if the CO content is too high, for example, the parameters are changed to the effect that a leaning takes place until the desired or legal limit value is reached.

The change in the parameters for the electronic control unit can then take place, for example, in buffers, until a new map or new characteristic curves are built up

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are. Of course, not all points have to be approached. It is sufficient to build up a framework from several measured variables and then to generally change the characteristic curves or maps using interpolation methods. One such Interpolation method is e.g. from DE-OS 30 06 known. Finally, the adapted parameters must again be permanently stored in the memory of the electronic Control unit 13 take place. This memory can, for example, be designed as an EPROM or a ROM with Basic data is used, but it is possible to change it using solder bridges.

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Claims (6)

R. 681 9.2.1981 Ve / Hm ROBERT BOSCH GMBH, 7OOO STUTTGART 1 Expectations / 1.) A method for adapting stored parameters in electronic control units for systems or machines, in particular internal combustion engines, characterized in that characteristic operating points are approached one after the other via a control program, that operating parameters are measured and compared with the target operating parameters assigned to the respective operating points and that depending on the deviation, the responsible parameters stored in the electronic control unit are changed. 2. The method according to claim 1, characterized in that the approach to the operating points and the assignment of Target operating parameters are carried out centrally, computer-controlled. 3. The method for internal combustion engines according to claim 2, characterized in that a central computer several Control terminals are assigned to adaptation sites. H. Method for adapting parameters stored in the form of characteristic curves or characteristic maps according to one of the preceding claims, characterized in that after measuring several operating points as support points, the characteristic curves or the characteristic field are altogether changed by interpolation methods. 5. Method according to one of the preceding claims, characterized in that falling below or exceeding a limit value of an operating variable corresponds to the achievement of a Setpoint is equated. 6. Device for carrying out the method, marked -., _ Characterized by a control computer (10) for starting the Operating points and a control circuit that consists of a processing and selection circuit (1 ^) for measured operating parameters, a target operating variable generator (16) and a characteristic variable correction circuit (17) which acts on the parameter memory of the electronic control unit (13).