Control device and method for triggering passenger protection means for a vehicle

Patent metadata

Field	Value
Publication number	US-9975509-B2
Application number	US-67389408-A
Country	US
Kind code	B2
Filing date	Jul 7, 2008
Priority date	Aug 23, 2007
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

A control device and a method for triggering a passenger protection arrangement for a vehicle are provided, an interface being provided that is used to receive at least one signal whose amplitude is a function of the vehicle battery voltage or a substitute voltage that takes its place. Furthermore, a trigger circuit is provided that triggers the passenger protection arrangement as a function of at least one signal. The interface has a circuit that derives at least one switching threshold from a supply voltage produced in the control device (substitute voltage that is retained for a certain amount of time in the autarchy case/under-supply case/contact problems) to detect the at least one signal, and one switching threshold that is directly derived from the battery voltage (standard), or from the amplitude of the bus voltage.

First claim

What is claimed is:

1. A control device for triggering a passenger protection arrangement in a vehicle, the control device comprising:
an interface receiving at least one signal derived from both a transmitted signal and a vehicle battery voltage of a vehicle battery that powers the vehicle;
a trigger circuit that includes a switching threshold input and that is configured to trigger the passenger protection arrangement as a function of a result of a comparison between the at least one signal and a switching threshold provided to the switching threshold input; and
a threshold deriving circuit that is structured to form the switching threshold;
wherein:
the threshold deriving circuit includes (a) a main line that is electrically connected to the switching threshold input of the trigger circuit, (b) a first branching line, and (c) a second branching line;
the first branching line and the second branching line simultaneously branch from the main line;
simultaneously, a supply voltage is provided onto an input side of the first branching line and the vehicle battery voltage is provided onto an input side of the second branching line;
the supply voltage is sourced by an energy reserve that is able to provide the supply voltage for a limited time after a fault occurs in the vehicle battery or a connection of the control device to the vehicle battery; and
the simultaneous branching of the first branching line and the second branching line from the main line:
causes a value of a voltage on the main line, which is provided as the switching threshold to the switching threshold input of the trigger circuit, to be set based on whichever of the voltages of the respective input sides of the first and second branching lines is greater and not based on the other of the voltages, even during the simultaneous provision of the supply voltage and the vehicle battery voltage onto, respectively, the input side of the first branching line and the input side of the second branching line;
causes that, whenever in a non-autarchy mode in which the vehicle battery is faultless and the connection between the control device and the vehicle battery is faultless, the vehicle battery effects the switching threshold without impact on the switching threshold by the supply voltage of the energy reserve; and
causes that, in response to transition from the non-autarchy mode to an autarchy mode in which the fault occurs in the vehicle battery or in the connection between the control device and the vehicle battery, for the limited time after the occurrence of the fault, the energy reserve effects the switching threshold without impact on the switching threshold by the vehicle battery voltage of the vehicle battery.

2. The control device of claim 1 , wherein a supply module produces the supply voltage as a digital level.

3. The control device of claim 2 , wherein an integrated circuit includes the interface, the threshold deriving circuit, and the supply module.

4. The control device of claim 1 , wherein the switching threshold is produced by a hysteresis circuit.

5. The control device of claim 1 , wherein the interface has a pull-up circuit for transmitting data.

6. The control device of claim 5 , wherein the pull-up circuit conducts the supply voltage to a transmission line via at least one second resistor and at least one second diode.

7. The control device of claim 1 , wherein the supply voltage is formed from the vehicle battery voltage when the vehicle battery voltage is available, and formed from an energy reserve when the vehicle battery voltage is not available.

8. The control device of claim 1 , wherein the threshold deriving circuit is structured such that whichever of the voltages present on the first and second branching lines is greater blocks the other of the voltages present on the first and second branching lines from being used for setting the switching threshold.

9. The control device of claim 1 , wherein:
the supply voltage is input to a first diode located in the first branching line;
the vehicle battery voltage is input to a second diode located in the second branching line;
the first diode and the second diode are each forward-biased in a direction of a comparator of the trigger circuit that includes the switching threshold input and that includes another input at which the at least one signal is applied for comparison to the value of the voltage at the switching threshold input; and
the first branching line is connected to the second branching line at a location of the switching threshold input of the comparator.

10. The control device of claim 9 , further comprising:
a voltage divider connecting the location of the switching threshold input of the comparator to ground.

11. The control device of claim 9 , wherein:
the switching threshold input to the comparator is a negative input of the comparator; and
the other input of the comparator is a positive input of the comparator.

12. The control device of claim 1 , further comprising:
an energy reserve;
a supply module that is configured to (a) produce the supply voltage from the vehicle battery voltage whenever the vehicle battery voltage is available and (b) produce the supply voltage from the energy reserve conditional upon the vehicle battery voltage being unavailable;
wherein the threshold deriving circuit is structured such that, when the vehicle battery voltage is unavailable, the switching threshold is formed exclusively by the supply voltage.

13. The control device of claim 1 , wherein, due to the structure of the first and second branching lines, whenever one of the voltages on the first and second branching lines is greater than the other of the voltages on the first and second branching lines, the presence of the greater of the voltages blocks the voltage at the switching threshold input from being set based on the lesser of the voltages.

14. The control device of claim 1 , wherein the energy reserve is a part of the control device.

15. The control device of claim 1 , wherein the energy reserve is one or more capacitors.

16. A control device for triggering a passenger protection arrangement in a vehicle, the control device comprising:
an interface receiving at least one signal derived from both a transmitted signal and a vehicle battery voltage of a vehicle battery that powers the vehicle;
a trigger circuit;
a first comparator; and
a second comparator;
wherein:
the at least one signal is applied to a respective first input terminal of each of the first and second comparators;
the vehicle battery voltage is applied to a second input terminal of the first comparator;
the supply voltage is applied to a second input terminal of the second comparator and is sourced by an energy reserve that is able to provide the supply voltage for a limited time after a fault occurs in the vehicle battery or a connection of the control device to the vehicle battery;
each of the first and second comparators is configured to compare voltage levels applied to its respective first and second input terminals and output (a) a first output signal whenever the voltage level at one of its respective first and second input terminals is greater than the voltage level at the other of its respective first and second input terminals and (b) otherwise a second output signal;
the control device is structured so that:
(i) whenever the vehicle battery voltage is greater than the supply voltage, which is always the case in a non-autarchy mode in which the vehicle battery is faultless and the connection between the control device and the vehicle battery is f

Assignees

• Schumacher Hartmut
• Bosch Gmbh Robert

Inventors

• Schumacher Hartmut

Classifications

• B60R2021/0104

  Communication circuits for data transmission · CPC title

• B60R21/01 Primary

  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 title

• Y10T307/766

  Cross-Sectional Technologies · mapped topic

• B60L2260/40

  Control modes · CPC title