Method for operating a restraint system connected to a bus line during faulty power supply

• US 6,566,765 B1
• Filed: 12/19/2000
• Issued: 05/20/2003
• Est. Priority Date: 03/28/1998
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Mueller, Norbert, Nitschke, Werner, Bauer, Joachim, Bischoff, Michael, Fendt, Günter, Karl, Otto, Schäffer, Stefan, Rinkens, Johannes
• Primary Examiner(s): Sircus, Brian
• Assistant Examiner(s): RIOS CUEVAS, ROBERTO JOSE
• Application Number:
  US09/647,291
• Time in Patent Office: 882 Days
• Field of Search: 307/9.1, 307/10.1, 307/64, 180/268, 180/270, 180/271, 280/728.1, 280/734, 280/735
• US Class Current: 307/10.1
• CPC Class Codes: B60R 2021/01075 between the airbag control unit and pyrotechnic fuses or equivalent actuators
• CPC Class Codes: B60R 2021/01122 Prevention of malfunction
• 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: G06F 1/24 Resetting means
• CPC Class Codes: G06F 1/30 Means for acting in the event of power-supply failure or interruption, e.g. power-supply fluctuations for resetting only G06F1/24
• CPC Class Codes: G06F 11/1441 Resetting or repowering
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06

Abstract

The restraint system is composed of a central control unit, which is connected via a bus line to a plurality of data processing units each of which is intended to drive one or more restraint devices. To keep the restraint system operational if the power supply in the central control unit becomes defective, a changeover to the vehicle battery voltage as the new supply voltage is effected in the central control unit. The central control unit then signals the changeover to the new supply voltage to all the data processing units. All the data processing units thereupon adjust their circuits to the new supply-voltage level.

Claims

1. A method for operating a restraint system networked via a bus line in conjunction with a defective power supply, a central control unit and a plurality of data processing units being connected to the bus line, each of the data processing units driving at least one restraint device, the central control unit supplying power for the data processing units, the method comprising the steps of:

if a defect occurs in a power supply present in the central control unit itself, effecting a changeover to a vehicle battery voltage as a new supply voltage;

signaling the changeover by the central control unit to all of the data processing units on the bus line; and

thereupon adjusting, by the data processing units, circuits associated with the data processing units to a level of the new supply voltage.

2. The method according to claim 1, further comprising the step of switching over a comparator, present in each of the data processing units and designed to detect a short circuit on the bus line, to a reference voltage that corresponds to the new supply voltage.

3. The method according to claim 1, further comprising the step of, once the data processing units have adjusted to the new supply voltage, sending the data processing units no further information signals or control signals from the central control unit other than trigger commands for the restraint devices.