EP1222378B1 - Device and method for controlling a drive unit - Google Patents

Description

State of the art

The invention relates to a device and a method for controlling a drive unit, in particular a Internal combustion engine in a vehicle.

In DE 42 31 449 A1 discloses a device for controlling the drive power of an engine with at least two Control units proposed, with a first Control unit with a first group of measuring devices and a second control unit having a second group of Measuring devices of the same measuring element is connected. there Special advantages arise in an engine of the consists of two independent cylinder banks and two of them Control units or control units is controlled. By the Coupling of several control units with only one measuring element to Capturing the farm size will be high availability and Operational safety guaranteed. The illustrated system with two control units has unbalanced Features and program code and shows originally a heavily used main and a weak one busy emergency running computer. To optimize computing time and memory are individual functions of the main computer in moved the emergency computer.

Instead of two control units is in DE 35 39 407 A1 a Computer system with two processors for controlling Characteristics of an internal combustion engine proposed. The both processors share the normal operation Computer load, in case of failure, each of the two Processors as an emergency computer an emergency operation upright can receive. Thus, only in emergency mode Required functions implemented on both processors. These functions in emergency mode, however, are opposite to the Normal operation a reduced power and Range of functions. By this increase in redundancy and a possible division of labor within the framework of the emergency function normal computer operation can be the security and the Working speed can be increased.

Due to the asymmetrical division of functions each Control unit or each processor must be the respective Functionality defined separately, realized, documented, tested and maintained. Likewise have to Both controllers or computers in development with equipped with expensive measuring means and / or emulation means become. Due to the asymmetrical definition of the Functional scope and thus the systems can, for example in the component assembly additional errors Confusion occur. At the same time one forces Further development or change of functionality in the existing system to consider both Control units or computers or their respective Functional scope, which is therefore very complex and very time and cost intensive.

US 3875390 shows a control of a drive system in Form of turbines with two connected computers with are each connected to a plurality of sensors and actuators. These computers use in their program memories identical software to set the sensor values to control values to process their controllers. This system is as built completely redundant system what the program code, So the software as well as the functionalities are concerned, so that in particular in case of error, the overall function with respect the turbine control only executed by a computer can be. That the overall functionality lies in everyone Calculator completely in front of what a highly complex system leads with increased effort.

This results in the task of realizing a optimized over the prior art Drive control with a very high level of functionality at Simultaneous reduction of complexity.

This is due to the distinguishing features of achieved independent claims.

Advantages of the invention

It is a control of a drive unit, in particular an internal combustion engine, indicated with a control unit, wherein the control unit includes at least two computers. Of the thereby for a computer too complex function of the Control unit or the control unit is on the at least split two computers in the one control unit. there contain the program memory of the two computers or Computing units the same program code which both Calculator an identical possible range of functions exhibit. Thus, the individual functionalities are advantageously less complex than the necessary one Overall range of functions selectable, which nevertheless the complex overall functionality across all computers or Processors results. When you use it is also largely go through the identical program code, but it can give individual parts, although in both memories or Computers are available but asymmetrical so only each be processed in or from a memory.

Advantageously, the function distribution can be up more than two computers take place or there can be more Computer be present in the overall system, but one execute other program code, so other features exhibit. The computers can then conveniently in be housed different control devices.

Appropriately, the two computers with identical possible functionality, for example via a serial or parallel bus system such as e.g. CAN or other serial Interfaces or a DPRAM, exchange information.

Another advantage is that by the symmetrical Functional division or the identical functional scopes the scope of functions defined only once, realized, documented, tested and maintained, but for both computers or arithmetic units can be used.

In the manufacture of the control unit e.g. in the prototype or in production, the program memory containing the Program code and thus contains the functionality advantageously just twice in the control unit equipped, which can not be confused.

In the development and application phase, one can Appropriately on one of the symmetrical sides focus. So it is enough a page with expensive To equip measuring aids or emulation devices. Due to the symmetrical division of functions or the symmetric functionality on both computers will be one Modular design of the control unit and the ECU program allows. Thereby are. Further developments by changing the existing functions and / or introducing new functions over one unbalanced structure much easier and faster possible because there are no interface and / or timing problems between the functions distributed to the computers. This results in lower development costs and shorter development times.

The key point is thus the symmetry of the functionality of the Computer system and the use of program memories with completely identical program code for the at least two Calculator or computing units in the control unit.

Further advantageous embodiments are in the Description and claims shown.

drawing

The invention will be explained in more detail below with reference to the embodiments shown in the drawing. 1 shows an overview block diagram of a control unit with two computing elements or computers, which control at least one operating variable in the vehicle, preferably the power of a drive unit, in particular an internal combustion engine.
FIG. 2 shows functional relationships of the two computers in the control unit and their surroundings.
FIG. 3 shows the concrete embodiment in functional relationships with reference to a lambda control for the injection calculation in the internal combustion engine.

Description of the embodiments

FIG. 1 shows an electronic control unit 100 which at least two computers 101 and 102, an input module 103, an output module 104 and a bus system 105 includes. Optionally, further components and / or Assemblies indicated by element 106 to the bus system 105th be coupled. These additional optional elements For example, additional memory elements and / or an additional bus input / output interface z. B. for diagnosis or connection of the control unit 100 with other controllers. The input module 103 can together with the output module 104 also as input / output module be summarized. The calculator 101 contains among other things a processor 109 and a the program memory 107 associated with this processor 109 program code stored in the program memory 107 corresponds to the possible scope of functions with respect to Control or regulation of the at least one operating variable how it can be processed by the processor 109. It is advantageous for the reasons mentioned above, if the first computer 101 and the second computer 102 also with a processor 110 and associated with it Program memory 108 are constructed completely identical. However, optionally different computers could be used as long as the possible range of functions both arithmetic units is identical. The input module 103 signals are supplied, which measured Operating variables of the drive unit, the drive train and / or of the vehicle or from which such farm sizes can be derived. Especially These are operating variables that are used to control a Internal combustion engine can be evaluated. The mentioned Signals are from measuring devices 111 to 113, in particular sensors, detected and via input lines 114 to 116 of the input module 103 supplied.

Via the output module 104 are further signals issued which actuators or actuators for Setting at least one operating size of Drive unit, in particular the internal combustion engine, the Press vehicle. The corresponding signals for Actuation of the actuators 117 to 119 are on the Output lines 120 to 122 delivered. In dependency of Input signals, derived operating variables and / or internal sizes form the computer 101 and 102 in the frame there implemented programs values for the output Control variables that the control elements in the sense of set the prescribed control strategy. Because it the control unit 100 is preferably a Control unit for controlling a drive unit, in particular an internal combustion engine, a vehicle is, for example, the position in a known manner detected by a driver operable control element, evaluated and a setpoint for a torque of Drive unit determined. This is then under Consideration of via the input module 103 received setpoints of other control systems, such as for example, a traction control, a Transmission control, etc. as well as internally formed setpoints (Limits, etc.) a setpoint for the torque determined. This is then in the preferred Embodiment of an internal combustion engine control in a setpoint for the position of the throttle valve, which in the The frame of a position control loop is set, converted. Furthermore, depending on the equipment of the internal combustion engine additional power-determining functions are provided, For example, controlling a turbocharger one Exhaust gas recirculation, an idle speed control u.s.w.

In addition, in internal combustion engines with Gasoline direct injection not only the air adjustment, but also the determination of the injected Fuel mass, the determination of a to be adjusted Air / fuel ratio, the specification of the Injection course (pre-injection, post-injection), the Control of a charge movement flap, etc. performance-determining, so that there beside the described a large number of other programs are to be provided Influence on the performance of the internal combustion engine and thus on the safety of the vehicle.

This variety of programs is in the form of a program code in the respective program memories 107 and 108 of the computer filed or loadable there. The just described, by the programs or the program code in the program memory represented functional ranges of a control unit are in general very complex. That's why these are supposed to be complex Functional ranges of the control unit symmetrical at least two computers in the named controller be split. The computers can e.g. about one Communication system, in particular a bus system such as CAN or another serial or parallel interface or a memory element, in particular a DPRAM information change. The program memories 107 and 108 of the two Calculators 101 and 102 contain the same program code. Furthermore, the identical program code is also largely the same go through, but there are individual justified parts can, which are processed asymmetrically. For example through hardware lines and on these transmitted signals then the required unbalanced will be processed Programs or sections in the program code activated or disabled. For the sake of simplicity of illustration these line connections through the communication system 105 represented or integrated into this.

The above-mentioned procedure is in Figure 2 in terms to an exemplary function distribution F1 to F4 shown. It is with 100 again the controller and with 101 and 102 the two computers. there 200 is an internal combustion engine with associated sensors and actuators shown. In this particular example is an internal combustion engine with 12 cylinders, divided into two cylinder banks of 6 cylinders each. There are The 12 cylinders are just examples, as well each of them different number of cylinders in the Cylinder banks 200a and 200b each with associated Sensor and other actuators be provided. So be For example, with a 12-cylinder engine from any computer 6 cylinders with respect to ignition and injection at one Ottomotor operated. The functional scope is symmetrical distributed to both computers. The functional scope F1 controls in each case a cylinder bank with associated sensors and Actuatorics of the internal combustion engine. At the same time sensor sizes become such as an air / fuel ratio, cam or crankshaft position, knock information, air mass, etc. from the engine 200 to the computers 101 or 102, in particular their functional scope F1 delivered (205, 206). Control signals (204, 207) from the Functional ranges F1 in turn reach the Internal combustion engine or its actuator. The oriented ones Connections 204 to 207 provide the functionality the transmission itself.

In this case, the possibility exists circuit parts or To use sensors by both processors. So can the Sensor, e.g. a hot film air mass meter, and a Input circuit, e.g. a low pass, especially from Cost reasons only once be present, the sensor signal, e.g. However, A / D-converted air mass stands the Functional scopes available in both computers.

Similarly, an adjuster, e.g. a secondary air pump, with the corresponding output stage in the control unit only from one Computer, the associated engine function, e.g. Secondary air control including diagnostics, but runs symmetric in both computers and also provides sizes for further engine functions.

In addition, actuators, e.g. Secondary air valve, for a first cylinder bank, through the calculator for the other, second cylinder bank are operated, although the associated Engine function in the computer for the first cylinder bank is running.

Another possibility is that the program code for Operator operation, e.g. for the position control of Throttle valve, symmetrically running in both computers, where but on a cylinder bank actually amp and Steller, so the actuator is operated on the other Cylinder bank, the signal from the computer not to control is used.

By the above statements as the following Illustration of the tank system will be clear that despite the Identity of the functionalities and the program code certain Unbalances are possible.

Other peripherals such as a tank system 201 is controlled by another feature F2 and supervised. This feature F2 is alike symmetrically contained in both computers 101 and 102. He However, for example, only by computer 101, ie processed asymmetrically. To do this, this function becomes F2 for example, by signals of separate hardware lines or by clear signals or data about the Communication system activated or deactivated. Consequently the diagnosis of the tank occurs when there is only one tank in the tank Vehicle exists only in a calculator. The corresponding Function F2 is on both computers in the program memory available, but it will only be activated on one page. The Communication relation between function F2 in computer 101 and the tank system 201 is through the connections 202 and 203 shown.

In addition, for more peripheral elements Functional ranges F3 or F4 be provided, which on the one hand sensor elements 209 and 210 by means Communication connection 213 or 214 read in and be processed (F3). On the other hand, as well Actuators, actuators 208 and 211 on the Communication links 212 and 215 through the Functional ranges F4 are operated. Likewise, sizes too or other control systems, such as a Traction control, a transmission control, etc. transmitted via the oriented connections 212 to 215 become. When it comes to the sensor element 209 and the Control element 208 by elements of the same control loop act, the functions F3 and F4 for example, also summarized as a function F34 to be viewed as.

In Figure 3 is a very specific embodiment of a 12-cylinder engine with concrete functionality shown. For example, said 12-cylinder engine has 4 parallel exhaust lines with 4 control probes 310 to 313, combined as lambda probes 300. In the engine control would therefore have provided a so-called Quadrolambdargelung which are due to their high complexity in addition to the increased effort and risks related to malfunction, especially security risks. By the Symmetric division of functions on two computers is obtained in each computer 101 or 102 in the control unit 100 only a stereo lambda control so much less complex functionality. From the probes 310 to 313 supplied signals arrive via the interfaces 314 to 317 for hardware preparation. This signal conditioning is done for computer 101 by elements 308 and 309 for Calculator 102 through the elements 306 and 307. Thus, the Calculator 102, the probe signals US1 and US2 and the computer 101, the probe signals US3 and US4 are supplied.

In each computer thus only two probe signals evaluated and the lambda control factors act as later executed on the injection calculation only on 6 Injectors. In blocks 304a and 304b, now becomes like already said the same stereo lambda control carried out. These are the prepared probe signals US1 and US2 as probe signals USX and USY in the scheme added. Likewise, the prepared probe signals US3 and US4 in block 304b also as USX and USY in the same stereo lambda control recorded. The from the Stereo lambda control resulting control factors FRX and FRY are respectively sent to subsequent blocks 305a and 305b for computer 102 or computer 101.

On the basis of the control factors FRX and FRY then takes place in the blocks 305a and 305b the same injection calculation for in this embodiment each 6th Injectors. The resulting Output size groups 318 and 319 are then the Amplifier blocks 320 and 321 transmitted.

Due to the same program code or identical Functional scopes are the function blocks as well identical. Likewise have input, output and Intermediate sizes of computers 101 and 102 identical Designations. So the outputs are 318 and 319, respectively alike labeled til to ti6, though these have physically different meaning. So will til once to control injector 1, EV1 and once used to control injector 7, EV7. However, this has no relevance to function or Range of functions or program code. From the power amplifier blocks 320 and 321 are then the injection valves 301 via Interface 302 or 303 driven.

In the figures 1, 2 and 3 thus already shows the addressed symmetric function distribution though parts possibly unbalanced be processed. Yet are functionality and functionality or program code identical for both computers and are in both computers go through independently. There is no redundancy and also no emergency running properties with encoders, power amplifiers or functionality. Such redundancy would be independent in addition to produce the concept of the invention.

Claims (8)

1. Device for controlling a drive unit, in particular an internal combustion engine in a vehicle, having at least one sensor and at least one actuator and controller, the device containing at least two processors, at least one operating variable of the drive unit being determined, and controlled variables being used to drive at least one actuator of the drive unit, in a manner dependent on the operating variable, in accordance with prescribable ranges of functions which yield an overall range of functions, the device being configured in such a manner that, in the at least one controller, the at least two processors process the possible overall range of functions in such a manner that each processor processes some of the ranges of functions, with the result that the overall range of functions is always shared between the at least two processors, and each of the at least two processors is assigned at least one program memory that contains program code, and the program code and the respective ranges of functions in the at least two program memories are identical, and the device is thus configured in such a manner that the overall range of functions results as the sum of the ranges of functions of the two processors.
2. Device according to Claim 1, characterized in that the at least one sensor is connected to a first processor, and the at least one actuator is connected to the first or to at least one second processor, the processors likewise being connected.
3. Device according to Claim 1, characterized in that at least two sensors and at least two actuators are provided, and each sensor and each actuator is respectively assigned to a processor and to the program memory assigned to the latter.
4. Control unit for controlling a drive unit, in particular an internal combustion engine of a vehicle, which contains two processors, at least one operating variable of the drive unit being determined, and controlled variables being used to drive at least one actuator of the drive unit, in a manner dependent on the operating variable, in accordance with prescribable ranges of functions which yield an overall range of functions, the control unit being configured in such a manner that the at least two processors process the possible overall range of functions in such a manner that each processor processes some of the ranges of functions, with the result that the overall range of functions is always shared between the at least two processors, and each of the at least two processors is assigned at least one program memory that contains program code, and the program code and the respective ranges of functions in the at least two program memories are identical, and the control unit is thus configured in such a manner that the overall range of functions results as the sum of the ranges of functions of the two processors.
5. Method for controlling a drive unit, in particular an internal combustion engine of a vehicle, at least one operating variable of the drive unit being determined, and controlled variables being used to drive at least one actuator of the drive unit, in a manner dependent on the operating variable, in accordance with prescribable ranges of functions which yield an overall range of functions, at least two processors processing the possible overall range of functions in at least one controller in such a manner that each processor processes some of the ranges of functions, with the result that the overall range of functions is always shared between the at least two processors, and the ranges of functions are prescribed by means of program code in at least one respective assigned program memory per processor, the possible ranges of functions for each processor and the program codes in the program memories which are assigned to the processors being identical, and the overall range of functions thus resulting as the sum of the ranges of functions of the two processors.
6. Method according to Claim 5, characterized in that the at least one operating variable is processed in a first processor, and at least one controlled variable from the first or from at least one second processor is used to drive the at least one actuator, the processors exchanging information.
7. Method according to Claim 5, characterized in that a distinction is made between operating variables of a first type and operating variables of a second type, the operating variables of a first type being processed in the ranges of functions of the two processors, and the operating variables of a second type respectively being processed only in the ranges of functions of one respective processor.
8. Method according to Claim 5 or 7, characterized in that a distinction is made between controlled variables of a first type and controlled variables of a second type, the controlled variables of a first type being formed, by the ranges of functions of a first processor, from the operating variables which are processed in the ranges of functions of a first processor, and the controlled variables of a second type being formed, by the ranges of functions of the first processor, from the operating variables which are processed in the ranges of functions of a second processor, the ranges of functions of the at least two processors exchanging information.

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