Control unit for a restraint system in a vehicle

Patent metadata

Field	Value
Publication number	US-10336274-B2
Application number	US-201515311731-A
Country	US
Kind code	B2
Filing date	Jun 1, 2015
Priority date	Jun 5, 2014
Publication date	Jul 2, 2019
Grant date	Jul 2, 2019

Abstract

A control unit for a restraint system in a vehicle, including an evaluation and control unit and at least one external ignition circuit interface to which a squib for activating the restraint system is connected via a go-line and a return line, the evaluation and control unit cyclically ascertaining, by measuring, an instantaneous ohmic loop resistance of the corresponding ignition circuit and comparing this with at least one stored threshold value. The evaluation and control unit determines an instantaneous temperature in the vehicle interior, close to the time for the measured value detection for ascertaining the ignition circuit loop resistance, the evaluation and control unit carrying out a temperature compensation of the ascertained ignition circuit loop resistance for the go-line and return line of the connected ignition circuit based on the instantaneous temperature in the vehicle interior, the go-line and return line being situated outside the control unit.

First claim

What is claimed is:

1. A device comprising:
a control unit; and
an interface connectable, via a go-line and a return line that are external to the device, to a squib of an external ignition circuit for activating a restraint system of a vehicle;
wherein the control unit is configured to:
cyclically perform the following:
perform a measurement to ascertain an instantaneous ohmic loop resistance of the ignition circuit;
determine an instantaneous temperature in an interior of the vehicle close to the time of the measurement;
based on the determined instantaneous temperature of the interior of the vehicle, carry out a temperature compensation of the ascertained instantaneous ohmic loop resistance for the go-line and the return line of the ignition circuit based on which a modified value of the instantaneous ohmic loop resistance is obtained; and
compare the modified value of the instantaneous ohmic loop resistance to at least one stored threshold value; and

control the squib based on a result of the comparisons.

2. The device as recited in claim 1 , wherein the control unit is configured to perform the determination of the instantaneous temperature in the interior of the vehicle is by reading in the instantaneous temperature in the interior of the vehicle from a temperature sensor via a communication interface.

3. The device as recited in claim 1 , further comprising:
a first conductor connecting the control unit to the interface and via which the control unit is connectable to the go-line; and
a second conductor connecting the control unit to the interface and via which the control unit is connectable to the return line, wherein:
the control unit is configured to:
determine an instantaneous internal temperature in the device; and
based on the determined instantaneous internal temperature in the device, carry out a temperature compensation of the ascertained instantaneous ohmic loop resistance for the first and second conductors;

the modified value is further based on the temperature compensation carried out for the first and second conductors.

4. The device as recited in claim 1 , wherein the control unit is configured to detect an instantaneous supply voltage via an analog-digital converter.

5. The device as recited in claim 4 , wherein, on the basis of the instantaneous supply voltage, the control unit is configured to determine power losses of components situated within a housing of the device.

6. The device as recited in claim 3 , wherein the control unit is configured to:
detect an instantaneous supply voltage via an analog-digital converter;
based on the detected instantaneous supply voltage, ascertain power losses of components situated within a housing of the device; and
calculate the instantaneous internal temperature in the device on the basis of the instantaneous temperature in the vehicle interior, the ascertained power losses, and a thermal resistance of the housing of the device.

7. The device as recited in claim 6 , further comprising a temperature sensor that is situated within the control unit and is configured to detect a temperature of an internal contact within the control unit, wherein the control unit is configured to calculate the instantaneous internal temperature in the device based on the detected temperature of the internal contact.

8. The device as recited in claim 7 , wherein the control unit is configured to calculate the instantaneous internal temperature in the device based additionally on power loss of the control unit and a thermal resistance between the internal contact within the control unit and an interior of the device.

9. The device as recited in claim 8 , wherein the determination of the instantaneous temperature in the interior of the vehicle is by a calculation by the control unit that is based on the instantaneous internal temperature in the device, and the ascertained power losses of components situated within the housing of the device, and a thermal resistance of the housing of the device.

10. The device as recited in claim 1 , further comprising a read-only memory storing at least one of parameters, parameter curves, and parameter tables on the basis of which the control unit is configured to carry out the temperature compensation.

Assignees

• Bosch Gmbh Robert

Inventors

• Schumacher Hartmut
• Kovacic Leonardo
• Gschwind-Schilling Rainer
• Karner Ruediger

Classifications

• B60R2021/01184

  Fault detection or diagnostic circuits · CPC title

• B60R2021/01129

  Problems or faults · CPC title

• B60R2021/01136

  Cut lines · CPC title

• B60R21/0173 Primary

  Diagnostic or recording means therefor · CPC title