Control unit and method for activating passenger protection means and sensor for outputting a crash-relevant signal

• US 8,818,639 B2
• Filed: 11/19/2008
• Issued: 08/26/2014
• Est. Priority Date: 01/03/2008
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Schumacher, Hartmut
• Primary Examiner(s): EL CHANTI, HUSSEIN A
• Application Number:
  US12/735,111
• Publication Number:
  US 20110035115A1
• Time in Patent Office: 2,106 Days
• Field of Search: 701/45
• US Class Current: 701/45
• CPC Class Codes: B60R 2021/01047 Architecture
• CPC Class Codes: B60R 21/01 Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents electrical circuits for transmission of signals between steering wheel and the vehicle itself B60R16/027; for electrically actuating belt retractor locking means B60R22/343
• CPC Class Codes: B60R 21/017 including arrangements for providing electric power to safety arrangements or their actuating means, e.g. to pyrotechnic fuses or electro-mechanic valves

Abstract

A control unit and a method for activating passenger protection arrangement, as well as a sensor for outputting a crash-relevant signal, are proposed. A digital signal, which is relevant for activating the passenger protection arrangement, is output with the aid of an interface. The interface has a plurality of power sources for influencing the signal edges of the digital signal.

Claims

1. A control unit for activating a passenger protection arrangement, comprising:

at least one interface configured to output a digital data signal, wherein the at least one interface has a plurality of power sources for influencing signal edges of the digital data signal; and

a microcontroller configured to control the activation of the passenger protection arrangement based on the digital data signal;

wherein the control unit configures the signal edges by switching the power sources to shape slopes of the signal edges, so as to provide an optimum electromagnetic compatibility (EMC).

2. The control unit as recited in claim 1, wherein the power sources are digitally switched at a predefined point in time to influence the signal edges, a first clock rate for the switching of the power sources being greater than data clock rate.

3. The control unit as recited in claim 2, wherein the interface includes:

a recognition circuit configured to recognize edges of the digital data signal;

a counter configured to start counting as a function of a recognition signal generated by the recognition circuit, the recognition signal being generated in response to recognition of a signal edge; and

a decoder configured to control the switching of the power sources as a function of the counter content.

4. The control unit as recited in claim 2, wherein the interface has four power sources.

5. The control unit as recited in claim 2, wherein the first clock rate is at least 100 times greater than the data clock rate.

6. The control unit as recited in claim 2, wherein the interface further includes an influencing circuit configured to influence current values of selected power sources.

7. The control unit as recited in claim 6, wherein the interface is situated on an integrated circuit having additional control unit functions.

12. The control unit as recited in claim 2, wherein the interface has four power sources, and wherein the first clock rate is at least 100 times greater than the data clock rate.

13. The control unit as recited in claim 12, wherein the interface is situated on an integrated circuit having additional control unit functions.

15. The control unit as recited in claim 2, wherein the control unit shapes the slopes of the signal edges so as to improve symmetry between rising and falling edges.

16. The control unit as recited in claim 2, wherein the power sources contribute to a total current that is superimposed on the digital data signal.

17. The control unit as recited in claim 2, wherein the control unit shapes the slopes of the signal edges so as to improve symmetry between rising and falling edges, and wherein the power sources contribute to a total current that is superimposed on the digital data signal.

18. The control unit as recited in claim 3, wherein the counter stops counting after reaching a value associated with a stop decoder word, at which point the decoder controls the power sources to maintain a currently existing switched state of the power sources until a next edge transition.

8. A vehicle sensor system, comprising:

a sensor for outputting a crash-relevant signal;

an interface connected to the sensor for outputting a digital data signal based on the crash-relevant signal, wherein the interface has a plurality of power sources for influencing signal edges of the digital data signal; and

a control unit that configures the signal edges by switching the power sources to shape slopes of the signal edges, so as to provide an optimum electromagnetic compatibility (EMC).

9. A method for activating a passenger protection arrangement of a vehicle, the method comprising:

receiving from a vehicle sensor at least one crash-relevant signal;

generating, from an interface, a digital data signal based on the crash-relevant signal, wherein signal edges of the digital data signal are influenced with the aid of a plurality of power sources in the interface;

switching the power sources to shape slopes of the signal edges, so as to provide an optimum electromagnetic compatibility (EMC); and

controlling, using a microcontroller, the activation of the passenger protection arrangement based on the digital data signal.

10. The method as recited in claim 9, wherein the power sources are digitally switched to influence the signal edges at predefined points in time, a first clock rate for the switching of the power sources being greater than data clock rate.

11. A control unit for activating a passenger protection arrangement, comprising:

at least one interface configured to output a digital data signal, wherein the at least one interface has a plurality of power sources for influencing signal edges of the digital data signal; and

a microcontroller configured to control the activation of the passenger protection arrangement based on the digital data signal;

wherein the signal edges are configured so as to provide an optimum electromagnetic compatibility (EMC), and

wherein the power sources are digitally switched at a predefined point in time to influence the signal edges, a first clock rate for the switching of the power sources being greater than data clock rate, wherein the interface includes a recognition circuit configured to recognize the output of the digital data signal, a counter configured to start counting as a function of a recognition signal generated by the recognition circuit, and a decoder configured to control the switching of the power sources as a function of the counter content, and wherein the interface includes an influencing circuit configured to influence current values of selected power sources.

14. The control unit as recited in claim 11, wherein the interface is situated on an integrated circuit having additional control unit functions.