Method and device for maintaining an actuator for an airbag control device

Patent metadata

Field	Value
Publication number	US-10173627-B2
Application number	US-201615557377-A
Country	US
Kind code	B2
Filing date	Jan 25, 2016
Priority date	Mar 13, 2015
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

Abstract

A method for maintaining an actuator for an airbag control device. The method has a step of impressing an electric current flow through the actuator using an electric voltage having a voltage value. In addition, the method has a step of ascertaining an electric measuring current through the actuator. Here, the electric measuring current through the actuator occurs on account of the impressed electric current flow through the actuator. In addition, the method has a step of executing a comparison of the electric measuring current through the actuator to a threshold value. Moreover, the method has a step of adjusting the voltage value of the electric voltage for impressing the electric current flow through the actuator as a function of the comparison.

First claim

What is claimed is:

1. A method for maintaining an actuator for an airbag control device, the method comprising:
impressing an electric current flow through the actuator using an electric voltage having a voltage value;
ascertaining an electric measuring current through the actuator, the electric measuring current through the actuator occurring on account of the impressed electric current flow through the actuator;
executing a comparison of the electric measuring current through the actuator to a threshold value; and
adjusting the voltage value of the electric voltage for impressing the electric current flow through the actuator as a function of the comparison;
wherein at least one of:
(a) the impressing is performed using a current source and the ascertaining is performed by measuring the electric measuring current at a location between the current source and the actuator; and
(b) (1) the impressing, executing, and adjusting are performed iteratively in a plurality of iterations, (2) in an initial one of the iterations, the adjusting includes raising the voltage value to a high voltage value in response to a result of the comparison of the respective iteration being that the electric measuring current does not satisfy the threshold value, and (3) the high voltage value is maintained in each subsequent one of the iterations until a first of the subsequent ones of the iterations in which the result of the comparison is that the electric measuring current satisfies the threshold value, in response to which the adjusting of the respective iteration includes lowering the voltage value to a low voltage value.

2. The method as recited in claim 1 , wherein the voltage value in the steps of impressing and adjusting is selected from a group of predefined voltage values consisting of the high voltage value and the low voltage value.

3. The method as recited in claim 1 , wherein in the step of adjusting, the voltage value of the electric voltage is increased from the low voltage value to the high voltage value if the comparison in step of executing shows that the electric measuring current through the actuator, which occurs on account of an electric current flow through the actuator impressed using an electric voltage having the first voltage value, is smaller than the threshold value.

4. The method as recited in claim 1 , wherein in the step of adjusting, the voltage value of the electric voltage is lowered from the high voltage value to the low voltage value if the comparison in step of executing shows that the electric measuring current through the actuator, which occurs on account of an electric current flow through the actuator impressed using an electric voltage having the second voltage value, is greater than the threshold value.

5. The method as recited in claim 1 , wherein in the step of adjusting, the voltage value of the electric voltage is kept at a minimum voltage value if the comparison in step of executing shows that the electric measuring current through the actuator, which occurs on account of an electric current flow through the actuator impressed using an electric voltage having the minimum voltage value, is greater than the threshold value.

6. The method as recited in claim 1 , wherein in the step of impressing, the electric current flow is impressed using a current value that is lower than a current value of an activation current for activating the actuator.

7. The method as recited in claim 1 , further comprising:
determining a voltage drop across the actuator in order to calculate an electrical resistance of the actuator using the electric measuring current and the voltage drop, and in the step of executing, the electrical resistance of the actuator is compared to a further threshold value for the comparison.

8. The method as recited in claim 1 , wherein the impressing is performed using the current source and the ascertaining is performed by measuring the electric measuring current at the location between the current source and the actuator.

9. The method as recited in claim 8 , wherein the ascertaining is performed using a measuring resistance located between the current source and the actuator.

10. The method as recited in claim 9 , wherein the ascertaining is performed using a control device, and the measuring resistance is located between two taps to which the control device is electrically connected.

11. The method as recited in claim 1 , wherein (1) the impressing, executing, and adjusting are performed iteratively in a plurality of iterations, (2) in an initial one of the iterations, the adjusting includes raising the voltage value to a high voltage value in response to a result of the comparison of the respective iteration being that the electric measuring current does not satisfy the threshold value, and (3) the high voltage value is maintained in each subsequent one of the iterations until a first of the subsequent ones of the iterations in which the result of the comparison is that the electric measuring current satisfies the threshold value, in response to which the adjusting of the respective iteration includes lowering the voltage value to a low voltage value.

12. The method as recited in claim 11 , wherein the low voltage value is 6.7 V.

13. The method as recited in claim 11 , wherein the high voltage value is at least 10 V.

14. The method as recited in claim 11 , wherein the high voltage value is 33 V.

15. The method as recited in claim 11 , wherein the low voltage value is less than 10 V and the high voltage value is at least 10 V.

16. The method as recited in claim 15 , wherein the low voltage value is 6.7 V.

17. The method as recited in claim 15 , wherein the high voltage value is 33 V.

18. The method as recited in claim 15 , wherein the low voltage value is 6.7 V and the high voltage value is 33 V.

19. The method as recited in claim 1 , wherein the threshold current is 50 milliampere.

20. A device for maintaining an actuator for an airbag control device, the device comprising:
a current source;
a current sensor; and
a current selector, wherein the current selector is configured to:
impress an electric current flow from the current source and through the actuator using an electric voltage having a voltage value;
ascertain an electric measuring current through the actuator using the current sensor, the electric measuring current through the actuator occurring on account of the impressed electric current flow through the actuator;
execute a comparison of the electric measuring current through the actuator to a threshold value; and
adjust the voltage value of the electric voltage for impressing the electric current flow through the actuator as a function of the comparison;

wherein at least one of:
(a) the ascertaining is performed by measuring the electric measuring current at a location between the current source and the actuator; and
(b) (1) the impressing, executing, and adjusting are performed iteratively in a plurality of iterations, (2) in an initial one of the iterations, the adjusting includes raising the voltage value to a high voltage value in response to a result of the comparison of the respective iteration being that the electric measuring current does not satisfy the threshold value, and (3) the high voltage value is maintained in each subsequent one of the iterations until a first of the subsequent ones of the iterations in which the result of the comparison is that the electric measuring current satisfies the threshold value, in response to which the adjusting of

Assignees

• Bosch Gmbh Robert

Inventors

• Schumacher Hartmut
• Karner Ruediger

Classifications

• G01R31/72

  Testing of electric windings (testing of transformers G01R31/62) · CPC title

• G01R31/2879

  related to electrical aspects, e.g. to voltage or current supply or stimuli or to electrical loads · CPC title

• B60R21/0173 Primary

  Diagnostic or recording means therefor · CPC title

• G01R31/005

  Testing of electric installations on transport means · CPC title

• B60R16/02 Primary

  electric {constitutive elements} · CPC title