DE4013728C2 - Control device for technical systems and machines - Google Patents

Description

The invention relates to a control device according to the preamble of claim 1.

Such control devices are diverse in Commitment. Serve for example in motor vehicles them to technical systems, for example Protection of occupants from accidental injuries, or machines, for example the internal combustion engine ne to control. Atypical events such as wise a collision or partial failure essential operational functions of the system or Machines are recorded using the memory net.

In a control device for occupant protection systems, such as an airbag, are the when the airbag is deployed statuses saved. This includes information about the faultless condition of the control device when triggered, the state of the inputs of the tax device, e.g. B. the information about the created Seat belt, the signal course or the character the characteristics of this course of the acceleration sensor, the timing of a collision process, etc. Only in this way is it possible to retrospectively Clarify accompanying circumstances of an accident and at for example to provide evidence that z. B. none The airbag was triggered incorrectly. In the interest of Vehicle manufacturer or the manufacturer of the tax device, however, it is necessary to each Exclude manipulation of the memory content.  

There are many ways to do this. At for example, memories are used in which the relevant data only registered once can be. Such a non-erasable Storage is then not reusable.

Another option is to use memory to be arranged in a sealed housing in order to do so evidence of tampering with the memory the visible mechanical damage to the housing to be able to lead. Such an arrangement is also even if the memory itself can be erased, especially ders complex and unfavorable to use.

Another option is the Spei to enlarge the space and for example the Saving a defined, usually relative small number of such atypical events to enable. Depending on the application, however such a memory is also limited Possible application and is difficult to reuse turn over, as a partially described Opposite memory in its application possibility a new memory is limited and in doubt trap its use is waived.

The invention has for its object a Control device of the type mentioned create the highest level of tamper evident unit, but with the memory with ge is reusable with little effort.  

The invention solves this problem by the kenn characterizing features of claim 1.

An erasable memory (e.g. an EEPROM) opens basically the possibility of reusable speed, as it usually contains new data as often as required can be described and then he is in his Properties not under from a new store separates. The reason for an erasable memory additional existing possibility, the memory content for manipulation at the expense of the manufacturer or To change the operator of the system or machine, is excluded by the possibility of this The memory is only deleted automatically at intervals of several days after the event requiring proof perform. The deletion process as such eludes the direct influence of everyone Vehicle users. The time limit in the form of several days, e.g. B. 10 days after the event sufficient security, the deletion only then perform if proof of the event is not more is needed.

DE 29 06 890 A1 discloses a control device for motor vehicles knows, at which - triggered by a sensor switch - at a proof event (e.g. accident) important vehicle data from a working memory in a non-volatile memory can be transferred. This data can then read out by authorities and workshops and (e.g. by UV radiation) be deleted.

The automatic deletion of the non-volatile memory, which is used to prevent Manipulations do not take place before a predetermined time has elapsed do not derive from DE 29 06 890 A1.

The implementation of the invention is different Way possible. So the delete command can automatically triggered from outside without further influence become. For this purpose, for example, an energy store cher used by a timer after Kind of a self-timer after the expiry of the pre an electrical erase pulse to the Emits memory. In contrast, the Embodiment with the features of the claim  2 another security. Only if the Spei for the corresponding period on or an operating voltage source is connected, the memory is deleted.

In control devices for internal combustion engines from Motor vehicles this means an automatic Deletion every few days after one critical operating case. Under such operating cases are only to be understood as those that are usually with a major failure of the internal combustion engine are connected. After a few days that is also Internal combustion engine repaired and the extinction the data contained in the memory is no longer required such.

The same applies to the application case Control device for an airbag. Since with that Triggering an airbag during a workshop visit is directly connected to the one in memory contained data can be recorded, that is then also deleting this data not critical. A new use of the memory or the entire control device, even in another Motor vehicle is then easily possible. Of the Connection of the control device to the operating chip The source of voltage can also be outside the motor vehicle stuff and serve only the goal that Trigger delete command and the control device to make it reusable.  

Especially when the control device is connected with a technical system or machine where the memory for recording Events of different relevance it may be advantageous to use the delete command suppress. An example of this is the recording of critical operating cases of an internal combustion engine machine or a control device of a motor vehicle stuff that differs depending on the driving conditions systems to influence driving dynamics controls. Because critical operating states also without subsequent stay in the workshop, can be the delete command for such applications are suppressed and only then triggered if, for example, as part of a workshop keep a record of what is in memory Data is made.

The control device according to the invention thus offers the ability to reuse control devices even if an event requiring proof is recorded. Manipulations of for this Recorded storage will be provided with Security suppressed because the memory is only in one large time interval and only if necessary special preparatory measures, such as for example the application of operating voltage, such as which becomes usable. Such a control device can also be used for spare parts in various use technical systems or machines. The Applications can therefore also be sequential to change.

Claims (3)

1. Control device for technical systems and machines, in particular in motor vehicles, with a microprocessor, and with a memory for recording events requiring verification, characterized in that the memory is erasable and that the delete command is only several days after recording an event can be triggered automatically. 2. Control device according to claim 1, characterized characterized that the delete command only triggers bar if the memory is during a time interval corresponding period an operating voltage source is switched on. 3. Control device according to claim 1 or 2, characterized in that the delete command can be suppressed.