Method for limiting the risk of errors in a redundant, safety-related control system for a motor vehicle
The invention relates to a method and a device for limiting the risk of faults in a control system, in particular a safety-relevant control system, wherein a preferably intelligent actuator controller (AST), by means of the application of a weighted mean value algorithm, calculates a new control value from the two control values determined by means of diverse redundancy by two independent fault-containment units (FCUs), which new control value, in spite of the occurrence of a fault in one of the two FCUs, causes an object to be controlled by the control system to be guided into a safe state, preferably quickly.
1. A method for limiting the risk of faults in an autonomic emergency braking (AEB) system of a vehicle, wherein the AEB system comprises two diversely redundant and independent fault-containment units (FCUs) ( 110 , 120 ) and an actuator controller (AST) ( 100 ), the method comprising:
determining by each of the FCUs ( 110 , 120 ) a control value for a braking force;
calculating by the AST ( 100 ), a new control value for the braking force from the control values for the braking force determined by the FCUs ( 110 , 120 ), in such a way that, if determined control values of the FCUs ( 110 , 120 ) deviate, the vehicle is guided into a safe state;
calculating by the AST ( 100 ), by means of the application of a weighted mean value algorithm which weights the control values of the FCUs ( 110 , 120 ) stipulating a higher braking force more heavily by a predefined weight (g) than the control values of the FCUs ( 110 , 120 ) stipulating a lower braking force, a new control value for the braking force from the two control values for the braking force determined by means of diverse redundancy by the FCUs ( 110 , 120 ); and
using the new control value for the braking force in the vehicle.
2. The method of claim 1 , wherein the control value determined in a current cycle, by means of a formation of a further weighted mean value from the control value of a past cycle and the determined control value in the current cycle, is corrected in such a way that the weighting of the control value in the past cycle increases when a difference between the two control values calculated in the current cycle increases.
3. The method of claim 1 , wherein the AST ( 100 ) is formed on a self-checking hardware.
4. The method of claim 1 , wherein the AST ( 100 ) files a fault message in a diagnosis store in the event of an occurrence of unequal control values.
5. An autonomic emergency braking (AEB) system of a vehicle, the system comprising:
two diversely redundant and independent fault-containment units (FCUs) ( 110 , 120 ), wherein each FCU ( 110 , 120 ) determines a control value for the braking force; and
an actuator controller (AST) ( 100 ), which calculates a new control value for the braking force from the control values for the braking force determined by the FCUs ( 110 , 120 ), in such a way that, if determined control values of the FCUs ( 110 , 120 ) deviate, the vehicle is guided into a safe state,
wherein the AST ( 100 ), by means of the application of a weighted mean value algorithm which weights the control values of the FCUs ( 110 , 120 ) stipulating a higher braking force more heavily by a predefined weight (g) than the control values of the FCUs ( 110 , 120 ) stipulating a lower braking force, calculates a new control value for the braking force from the two control values for the braking force determined by means of diverse redundancy by the FCUs ( 110 , 120 ), and uses this new control value for the braking force in the vehicle.
6. The system of claim 5 , wherein the control value determined in a current cycle, by means of a formation of a further weighted mean value from the control value of a past cycle and the determined control value in the current cycle, is corrected in such a way that the weighting of the control value in the past cycle increases when a difference between the two control values calculated in the current cycle increases.
7. The system of claim 5 , wherein the AST ( 100 ) is formed on a self-checking hardware.
8. The system of claim 5 , wherein the AST ( 100 ) files a fault message in a diagnosis store in the event of an occurrence of unequal control values.
9. A motor vehicle, comprising:
an autonomic emergency braking (AEB) system, comprising:
two diversely redundant and independent fault-containment units (FCUs) ( 110 , 120 ), wherein each FCU ( 110 , 120 ) determines a control value for the braking force; and
an actuator controller (AST) ( 100 ), which calculates a new control value for the braking force from the control values for the braking force determined by the FCUs ( 110 , 120 ), in such a way that, if determined control values of the FCUs ( 110 , 120 ) deviate, the motor vehicle is guided into a safe state,
wherein the AST ( 100 ), by means of the application of a weighted mean value algorithm which weights the control values of the FCUs ( 110 , 120 ) stipulating a higher braking force more heavily by a predefined weight (g) than the control values of the FCUs ( 110 , 120 ) stipulating a lower braking force, calculates a new control value for the braking force from the two control values for the braking force determined by means of diverse redundancy by the FCUs ( 110 , 120 ), and uses this new control value for the braking force in the motor vehicle.