Method and device for controlling firing circuits for restraining devices

• US 6,587,769 B2
• Filed: 11/20/2001
• Issued: 07/01/2003
• Est. Priority Date: 12/22/2000
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Schumacher, Hartmut, Rupp, Andreas, Tschentscher, Harald, Ulmer, Michael, Taufer, Peter, Henne, Achim, Otterbach, Jens
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): Hernandez, Olga
• Application Number:
  US09/990,530
• Publication Number:
  US 20020177933A1
• Time in Patent Office: 588 Days
• Field of Search: 701/45, 701/34, 701/36, 280/734, 280/735, 307/9.1, 307/10.1, 102/293, 102/218, 102/206
• US Class Current: 701/45
• CPC Class Codes: F02D 13/0207 changing valve lift or valve lift and timing
• CPC Class Codes: F02D 13/0253 Fully variable control of valve lift and timing using camless actuation systems such as hydraulic, pneumatic or electromagnetic actuators, e.g. solenoid valves
• CPC Class Codes: F02D 2041/001 for engines with variable valve actuation
• CPC Class Codes: F02D 2200/0402 the parameter being determined by using a model of the engine intake or its components
• CPC Class Codes: F02D 2200/0406 Intake manifold pressure
• CPC Class Codes: F02D 41/0002 Controlling intake air
• CPC Class Codes: F02D 41/008 Controlling each cylinder individually
• CPC Class Codes: F02D 41/18 by measuring intake air flow
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A device and a method are proposed for controlling firing circuits for an element of restraint, individual transistors of the output stages being controlled by bit combinations, and impermissible bit combinations lead to an error message to a processor. In addition, a firing current is measured, in order to estimate a firing energy from it, so that efficient energy management can be carried out. Furthermore, determination of the firing current makes it possible to update a crash protocol as to whether the firing circuit was activated or not. When a voltage of the energy reserve is exceeded, it is further proposed to switch over to pulse operation for operating the output stages. Thereby a greater resistance to short-circuits and a higher efficiency are achieved.

Claims

1. A device for controlling firing circuits for elements of restraint in a motor vehicle, comprising:

a processor;

a firing circuit control;

a plurality of firing elements;

a plurality of output stages for each of the plurality of firing elements, each output stage being in communication with a respective inhibiting input for releasing an associated one of the plurality of output stages;

an energy reserve for an operation of the firing circuits, the firing circuits including the plurality of output stages and the plurality of firing elements, wherein;

the processor releases the plurality of output stages for triggering the elements of restraint when a crash of the motor vehicle occurs; and

a safety IC for releasing the plurality of output stages during the crash and including an arrangement for performing a crash recognition, wherein the firing circuit control includes;

an arrangement for evaluating an activating command,

an arrangement for operating the plurality of output stages,

an arrangement for measuring a firing current,

an arrangement for handling an error in the activating command, and

an arrangement for measuring an energy reserve voltage and for switching between a pulse operation and a continuous operation for the plurality of output stages, the safety IC setting each inhibiting input after a start-up of the device.

2. The device according to claim 1, further comprising:

a crash recorder; and

a firing current register, wherein;

the arrangement for measuring the firing current registers a current of a current source, in each case, in one of the plurality of output stages and stores a measuring result in the firing current register, the measuring result then being transmittable to the crash recorder.

3. The device according to claim 2, wherein:

the arrangement for measuring the firing current logically links a reference current of a regulated current source of the one of the plurality of output stages and an adjustment information, so as to determine whether the firing current is present.

4. The device according to claim 1, wherein:

the arrangement for handling the error in the activating command transmits an error message to the processor when the arrangement for handling the error in the activating command recognizes the activating command as being faulty.

5. The device according to claim 3, wherein:

for a registration of a firing energy, the processor uses the measuring result from the firing current register for ascertaining the firing energy, and

the processor switches off the plurality of output stages by using the firing circuit control when the firing energy reaches a predefined value.

6. The device according to claim 1, wherein:

the arrangement for measuring the energy reserve voltage and for switching between the pulse operation and the continuous operation registers the energy reserve voltage and compares the energy reserve voltage to a threshold value, and

the arrangement for measuring the energy reserve voltage and for switching between the pulse operation and the continuous operation switches to the pulse operation when the threshold value is exceeded, and otherwise to the continuous operation.

7. The device according to claim 1, wherein:

the safety IC disables the plurality of output stages by setting each respective inhibiting input.

8. A method for controlling firing circuits for elements of restraint, in which output stages include transistors, the method comprising the steps of:

causing a processor to activate the firing circuits via a firing circuit control;

in order to achieve a control of the processor, providing at least two bits as a bit combination for controlling one of the transistors; and

signaling an error message to the processor by the firing circuit control when an impermissible bit combination occurs.

9. The method according to claim 8, further comprising the step of:

activating one of the output stages by performing a sequence that includes;

placing inhibiting inputs of the firing circuit control for the output stages at a predefined voltage level by the safety IC,

causing the processor to send a release command for each one of a plurality of function blocks, and

causing the firing circuit control to receive a bit combination for activating the one of the output stages from the processor.

10. The method according to claim 9, wherein:

when the sequence is not maintained, an automatic breaking off of the activating of the one of the output stages occurs.