ACCELERATION SENSOR ARRANGEMENT, SAFING ARRANGEMENT FOR AN ACTIVATION SYSTEM, ACTIVATION SYSTEM

• US 20090024284A1
• Filed: 02/07/2006
• Published: 01/22/2009
• Est. Priority Date: 02/07/2006
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Inventors: Bourbiel, Felix, Klink, Brian, Piroth, Juergen
• Granted Patent: US 8,121,761 B2
• Time in Patent Office: Days
• US Class Current: 701/45
• CPC Class Codes: B60R 2021/01322 comprising variable thresholds, e.g. depending from other collision parameters
• CPC Class Codes: B60R 21/0132 responsive to vehicle motion parameters , e.g. to vehicle longitudinal or transversal deceleration or speed value
• 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

An acceleration sensor arrangement comprises, in one package, an acceleration threshold detector for detecting acceleration and for providing an output signal and a processor circuit for receiving the output signal. The acceleration threshold detector provides an output signal having a first value when the acceleration is less than a predetermined threshold and is arranged to switch the output signal from the first value to a second value when the acceleration reaches the predetermined threshold. The processor circuit generates an event signal to trigger an event, such as the closing of a safing transistor switch in an airbag system, in response to the output signal from the acceleration threshold detector switching to the second value.

Claims

1. An acceleration sensor arrangement comprising in one package:

an acceleration threshold detector for detecting acceleration and for providing an output signal having one of a first value and a second value, the output signal having the first value when the acceleration is less than a predetermined threshold, the acceleration threshold detector being arranged to switch the output signal from the first value to the second value when the acceleration reaches the predetermined threshold; and

a processor circuit for receiving the output signal from the acceleration threshold detector and for generating an event signal to trigger an event in response to the output signal switching to the second value.

2. The acceleration sensor arrangement according to claim 1, wherein the acceleration threshold detector comprises at least one of a piezo element and a micromachined element.

3. The acceleration sensor arrangement according to claim 1, further comprising means for programming the value of the predetermined threshold.

4. The acceleration sensor arrangement according to claim 1, wherein the event includes at least one of the following:

opening a transistor switch;

closing a transistor switch;

activating an activation element; and

initiating a software interrupt.

5. The acceleration sensor arrangement according to claim 1, wherein the processor circuit is adapted to provide an event signal such that the event is maintained for a programmable predetermined duration.

6. The acceleration sensor arrangement according to claim 1, wherein the processor circuit is adapted to provide a programmable delay between when the output signal from the acceleration threshold detector switches from the first value to the second value and the generation of the event signal.

7. The acceleration sensor arrangement according to claim 1, wherein the acceleration threshold detector and the processor circuit are integrated on the same integrated circuit.

8. A safing arrangement for an activation system comprising a safing transistor switch and an acceleration sensor arrangement as claimed in claim 1, the acceleration sensor arrangement being arranged to provide the event signal to the safing transistor switch to control the opening and closing of the safing transistor switch.

9. The safing arrangement according to claim 8, wherein the safing transistor switch is integrated on the integrated circuit comprising the acceleration threshold detector and the processor circuit.

10. An activation system comprising:

activation element for activating the activation system;

main processor circuit for providing an activation control signal to the activation element;

an acceleration sensor arrangement according to claim 1 for providing the event signal to the main processor circuit, the main processing means for providing the activation control signal to activate the activation element in dependence on the event signal.

11. The acceleration sensor arrangement according to claim 2, further comprising means for programming the value of the predetermined threshold.

12. The acceleration sensor arrangement according to claim 2, wherein the processor circuit is adapted to provide an event signal such that the event is maintained for a programmable predetermined duration.

13. The acceleration sensor arrangement according to claim 3, wherein the processor circuit is adapted to provide an event signal such that the event is maintained for a programmable predetermined duration.

14. The acceleration sensor arrangement according to claim 4, wherein the processor circuit is adapted to provide an event signal such that the event is maintained for a programmable predetermined duration.

15. The acceleration sensor arrangement according to claim 2, wherein the processor circuit is adapted to provide a programmable delay between when the output signal from the acceleration threshold detector switches from the first value to the second value and the generation of the event signal.

16. The acceleration sensor arrangement according to claim 3, wherein the processor circuit is adapted to provide a programmable delay between when the output signal from the acceleration threshold detector switches from the first value to the second value and the generation of the event signal.

17. The acceleration sensor arrangement according to claim 4, wherein the processor circuit is adapted to provide a programmable delay between when the output signal from the acceleration threshold detector switches from the first value to the second value and the generation of the event signal.

18. A safing arrangement for an activation system comprising a safing transistor switch and an acceleration sensor arrangement as claimed in claim 2, the acceleration sensor arrangement being arranged to provide the event signal to the safing transistor switch to control the opening and closing of the safing transistor switch.

19. A safing arrangement for an activation system comprising a safing transistor switch and an acceleration sensor arrangement as claimed in claim 6, the acceleration sensor arrangement being arranged to provide the event signal to the safing transistor switch to control the opening and closing of the safing transistor switch.

20. A safing arrangement for an activation system comprising a safing transistor switch and an acceleration sensor arrangement as claimed in claim 7, the acceleration sensor arrangement being arranged to provide the event signal to the safing transistor switch to control the opening and closing of the safing transistor switch.