Method for modifying data in the parameter memory of a motor vehicle computer.

The invention relates to a method for changing the data in the parameter memory of a controller for motor vehicles in on-line operation, the controller except the parameter memory contains at least one microcomputer and for controlling and regulating the fuel injection and / or other functions depending on operating variables such as engine speed, boost pressure, accelerator position etc., which are determined by means of measuring sensors, is adapted as well as to an apparatus for performing this method.

The properties and behavior of a motor vehicle engine are determined by a number of parameters and characteristic curves, hereinafter referred to as data in a semiconductor memory of the controller, called the parameter memory is housed. For optimum tuning of the engine behavior, these data must be available and can be changed throughout the engine and vehicle development phase. The change in these data must even "on-line", ie be possible with the engine running.

It has become known to use for the data change during development special rig controller, whose parameter memory is in a separate device, often referred to as a programming device, housed. The parameter memory is available in two identical versions in the programmer. While the controls are the data a copy of the parameter memory for controlling the motor available, data changes can be carried out in the second copy. After completion of the change of a data byte, the two copies of the parameter memory are swapped and therefore the change to take effect. but addition to the data of the parameter memory contains the control program of the controller.

The controller is connected to the programming device via a ribbon cable. Top of this cable are applied by the microprocessor, the desired address to the parameter memory and then read out at these addresses from stored data as well as program instructions from the parameter memory. Use the alphanumeric keyboard of the programmer can by entering the corresponding addresses, the data of the parameter memory on the screen and changed if necessary. Both the data and the addresses of the parameter memory are displayed as hexadecimal numbers, just the changed data must be entered in hexadecimal form.

The disadvantages of this known solution are obvious:

Incorrect data or address inputs can cause a non-predictable behavior of the engine, on the one hand because the controller control program and the engine and vehicle-specific data are stored in the same memory, on the other hand because the input data are hardly tested.

By using only a memory for program and data on the above-mentioned ribbon cable and program instructions are transmitted, which can in electrical interference can cause crashes.

The swapping of the two parameter memory copies after changing only one byte of data can lead to inconsistent data, which in turn can cause an unforeseeable motor behavior.

The data change in hexadecimal form, stating physical memory addresses can be practically hardly done by programmers and by the test rig personnel.

The special rig controller is not the same as the later series regulator, since the rig controller includes a multi-chip microcomputer, while the series regulator for reasons of cost typically includes a single-chip microcomputer.

It is an object of the invention to provide a method and a suitable apparatus for carrying it out, with which the disadvantages of the known solutions can be eliminated.

This goal can be achieved, in which according to the invention designed as a read-write memory parameter memory in an address area in at least one, is generally divided several, data areas, and in a staging area by a method of the aforementioned type, said at the start address the address area memory lying contains the addresses of all data areas and the buffer zone and the capacity of the temporary storage area at least equal to the capacity of the largest data area is selected and that the amount provided for one data area, determinable in a communication with the controller dialog computer changed data is written to the staging area, then the address of the data area is replaced by the address of the temporary storage area in the address, then the changed data are transferred from the temporary storage area in the data area and finally in the address, the address of the data area is changed back to the original address.

The invention allows the byte writing new data into the buffer area or the copying of this area in the correct address range during the times in which no memory access is performed by the control program. The switching from the old data of a data area to the new data can be done very quickly. Since this address change is done by the communication program, without temporarily release the parameter memory, there may be no inconsistent addresses.

It is expedient if the changed data before writing are initially stored in the temporary storage area to a Nachbil tion of the parameter memory dialog computer since by this means the security and flexibility of the process is to be increased.

An apparatus for carrying out the method according to the invention with a controller for motor vehicles, having at least a microcomputer and a parameter memory for engine and vehicle specific data, eg for characteristics and for controlling and regulating fuel injection and / or other functions in response to operating variables, such as eg speed, boost pressure, throttle position, etc., which are determined by means of transducers, is furnished with a dialog calculator for determining and temporary storage is inventively awarded characterized in the data to be changed in the parameter memory that the controller with the dialogue computer via a preferably serial interface is connected, the parameter memory is constructed as a read-write memory and the dialogue computer contains a replica of the parameter memory for storing the data of the parameter memory and the data to be changed.

It should be noted that a controller for motor vehicles of the type mentioned for example in EP-A2-207 described 051st

The invention together with further advantages and features is explained in more detail below with reference to an exemplary embodiment which is illustrated in the drawing. In the drawings Fig. 1 is a schematic overview of a controller for motor vehicles, which is connected to a dialogue computer, Fig. 2 schematically shows the organization of the parameter memory, Fig. 3a to 3e schematically the individual sections of the data modification, and Fig. 4a-4b is a schematic flowchart of a data change, without considering the error handling.

According to FIG. 1, an electronic controller 1 is connected via a generally only 3-core cable 2 with a dialogue computer 3. Over a number of lines 4 of the controller 1 is in unspecified interest here way with donors of an engine or of the motor vehicle, for example for speed, temperature, etc., and with one or more actuators, for example for the control rod of the injection pump of a diesel engine in conjunction ,

The controller 1 includes in this case three microcomputer 5, 6 and 7, which are connected via a parallel bus 8 with a parameter memory. 9 The parameter memory 9 contains the engine or vehicle-specific data which are required for the control of the motor or operation of the vehicle. Via the bus 8 may each microcomputer 5, 6, 7 with each other microcomputer exchange data, and read data from the parameter storage 9, simultaneously with only two of the microcomputer or the microcomputer can communicate with the parameter memory. The parameter memory 9 is formed in series device as a read only memory, during the development phase is a read / write memory. The microcomputer 5 has a special position in this multi-computer system, it contains the communication program through the serial port (cable 2) communicates with the Dialog computer 3 and he is the only write access to the parameter memory 9 via a line 10th

The dialogue computer 3 is designed as a portable microcomputer and essentially consists of a central processing unit 11 (CPU), a memory 12 and a serial input / output unit 13 for communication with the operator standing a color graphic screen 12 and an alphanumeric keyboard 15 to available. The memory 12 of the dialog computer 3 is composed of a read only memory that contains the dialog computer program and a read / write memory containing both the program data and a copy of the parameter memory of the electronic controller 9 first

The 3-wire cable 7 is used for serial transmission of data between the dialogue computer 3 and the electronic controller 1. This serial interface operates half duplex and corresponds to the standard RS-485. The data exchange is carried out by so-called news; the importance of data within a message and the allowable sequence of the messages are defined (protocol) through a data exchange specification.

According to FIG. 2, the parameter memory 9 from a memory located at the beginning of the address area A, one or more data fields Di, 1 ≦ i ≦ n, and an intermediate storage area Z at the end of the parameter memory. The address area A contains the addresses of all the data areas Di, and the address of the buffer area Z; the data areas Di contain the individual motor and vehicle-specific data and the intermediate storage area Z is used for temporarily storing changed data of a particular data area Di. The size of the memory area Z must be greater or equal to the maximum of the sizes of all data areas Tue, 1 ≦ i ≦ n chosen will.

In FIG. 3a to 3e is a data change in a specific data area Dj, 1 ≦ j ≦ n explained in the individual steps. For simplicity, are shown in Fig. 3a to 3e, only the parameter memory 9, the communication program of the microcomputer 5 and the read from the parameter memory 9 control programs that may be distributed to the microcomputer 5, 6, 7.

The data of the data area DJ are displayed by entering an appropriate command from the keyboard 15 of the computer 3 dialog on the screen 14th Part of the dialogue computer program, namely the so-called text editor now allows you to change individual data values. The completion of the data change and therefore the adoption of the revised data is communicated to the dialogue computer program again by means of a com mand. Now the data of the data area will be examined by Dj dialogue computer program for correctness and compatibility with the other data. Incorrect or implausible data are rejected with an error message on the screen 14 of the computer 3 dialogue and offered to correct.

If the changed data of the data area Dj recognized as correct and compatible with the rest of the data, they are for the time being in the program data memory of the dialogue computer 3 (and not in the copy of the parameter memory) buffered. Fig. 3a shows the state before the data change from the perspective of the electronic governor 1.

Next, as shown in Fig. 3b, the dialogue computer 3 instructed by a message to the electronic controller 1 to write the following data sent to the buffer memory area Z. The communication program of the microcomputer 5 writes the data received from Dialog computer 3 data of the data area Dj via the bus 8 using the write line 10 in the staging area Z. The data is only ever written one byte in the parameter memory 9 when no control program it accesses. The control programs themselves are still working even with the old data of the data area Dj. When all the data of the data area Dj been successfully written to the temporary memory area Z, this is the dialogue computer communicated 3 per message (response); as well as when, for some reason could not be executed. In the latter case decides the dialogue computer 3, either to repeat or reject what is communicated to the operator by means of an error message on the screen to order.

In the section according to Fig. 3c of the dialogue computer 3 Instructs the electronic controller 1, in the address A, the address of the data area Dj by the address of Zwischenspei to replace cherbereiches Z. Now only the data change for the control programs takes effect; they work from the next access with the new data of the data region Dj, which are stored in the buffer memory area Z being.

To be able to carry more data changes, the new data of the data area Dj from the temporary storage area Z be copied back to their original place by order of the Dialog computer. 3 This step is shown in Fig. 3d; the control programs are still working with the new data of the data area in Dj staging area Z.

As a final step of the process will be as shown in Fig. 3e, again replaced in the address A the address of the data area by Dj the original address of the data area. The control programs are now working with the new data of the data area Dj their original place, the staging area Z is free for other data modifications. Thus, the data change for the electronic governor 1 is finished. Finally, the dialogue computer takes 3 the changed data of the data area Dj in his copy of the parameter memory. The dialogue computer 3 can receive further orders for changing data.

A possible flow chart that can be used in connection with the invention is shown in FIGS. 4a to 4c. The acronym DB stands for "data area". A more detailed explanation of the diagram is omitted.

The main advantages of the invention are summarized again below:

The first and the third step of the data change, namely the writing in the staging area and copying this to the original course can be performed byte whenever the control programs the parameter memory not using straight, without affecting the consistency of the data (the addressing of data is always made through the address range).

The switching from the old data of a data area to the new data in the second step is effected by variation of only one address (generally 2 bytes), that is very fast. Since the communication program performs this address change, without releasing the parameter storage in the meantime, there may be no inconsistent addresses.

Plausibility and consistency of all data of the parameter memory are carried out by the Dialog computer. 3

In the embodiment shown, the controller 1 includes a multicomputer system with three microcomputers. For this purpose it should be noted that the controller 1 can also be constructed with more than three microcomputers with only a single microcomputer, or two microcomputers and when required.