Method for the efficient protection of safety-critical functions of a controller and a controller
In a method for operating a controller, at least one input data are processed into at least one output data by using an algorithm. For checking the output data, a second determination of the output data is performed only for output data in a group that does not contain all possible output data.
1. A method for operating a controller, comprising
processing input data into output data in a first determination of the output data by using a first algorithm,
determining a first group of the output data that does not contain all possible output data,
performing a first check as to whether output data determined in the first determination is contained in the first group, and
performing a second determination of the output data to perform a second check of the output data only for those output data contained in the first group.
2. The method of claim 1 , wherein the output data contained in the first group describe an intervention by an actuator or cause an intervention by an actuator or are safety-critical output data, or a combination thereof.
3. The method of claim 2 , wherein the output data are used only when confirmed by the second check.
4. The method of claim 1 , wherein the controller is at least one of an image processing controller and a controller of a motor vehicle.
5. The method of claim 1 , wherein the second determination of the output data is performed using identical hardware, but using a second algorithm different from the first algorithm.
6. The method of claim 1 , wherein the second determination of the output data is performed using a redundant hardware component.
7. The method of claim 6 , wherein the second determination of the output data is performed using an additional processor.
8. The method of claim 7 , wherein the data integrity is checked using at least one of a check value, a cyclic redundancy check (CRC) process and an error-correcting-code (ECC) process.
9. The method of claim 1 , further comprising performing a self-test of at least one hardware component involved in at least one of the first and second determination, after determining whether output data determined in the first determination is contained in the first group and before the second determination is performed.
10. The method of claim 1 , further comprising checking integrity of the algorithm stored in a storage device, after the first check and before the second determination.
11. The method of claim 1 , further comprising checking the input data stored in a storage device after the first check and before the second determination.
12. The method of claim 1 , further comprising storing at least one input data or at least an intermediate result, or both, in a storage device for the second determination.
13. The method of claim 12 , wherein the at least one input data or the at least an intermediate result are stored until a decision is made that the second determination will not be performed.
14. The method of claim 12 , wherein the at least one input data or the at least an intermediate result are stored until the second check is concluded.
15. The method of claim 1 , wherein the second determination is limited to computing operations related to determining the output data belonging to the first group.
16. The method of claim 15 , wherein the controller is configured for image processing and operates using hypotheses, and wherein only a confirmed hypothesis resulting in the output data is checked.
17. A controller comprising control hardware and control software, said controller configured to
process input data into output data in a first determination of the output data by using a first algorithm,
determine a first group of the output data that does not contain all possible output data,
perform a first check as to whether output data determined in the first determination is contained in the first group, and
perform a second determination of the output data to perform a second check of the output data only for those output data contained in the first group.