Method and system for diagnostic measurement of fault condition for common connected squib loops in restraint control module
AssigneeAutoliv ASP, Inc.
InventorsVincent Colarossi, Stuart Koch
Life of this patent
Estimating the term…
Abstract
A method and system for diagnosing a fault condition in common connected squib loops is disclosed. A current source supplies current to the feed terminal for the first squib loop and current is returned through the feed terminal for the second squib loop. The voltage is measured between the feed terminal for the first squib loop and the feed terminal for the second squib loop.
Claims20
A system for diagnosing leakage in a dual squib loop with a common return line, the system comprising;
- a first high side driver connected to a firing voltage source and a first feed terminal for the first squib loop;
- a first low side driver connected to a first return terminal for the first squib loop and a ground;
- a second high side driver connected to the firing voltage source and a second feed terminal for second first squib loop;
- a second low side driver connected to a second return terminal for the second squib loop and the ground;
- a testing current source being connected to source current to the first feed terminal for the first squib loop and return current through the second feed terminal for the second squib loop;
- a voltage measurement circuit configured to measure a voltage between the first feed terminal and the second feed terminal.
A method for diagnosing leakage in a dual squib loop configuration having a first squib loop and a second squib loop with a common feed line, the method comprising the steps of:
- providing current to the first high side feed terminal of the first squib loop and returned from the second high side feed terminal of the second squib loop;
- measuring a voltage between the first high side feed terminal first squib loop and the second high side feed terminal of the second squib loop;
- determining a resistance between the first high side feed terminal first squib loop and the second high side feed terminal of the second squib loop.
A system for diagnosing leakage in a dual squib loop with a common feed line, the system comprising;
- a first high side driver connected to a firing voltage source and a first feed terminal for the first squib loop;
- a first low side driver connected to a first return terminal for the first squib loop and a ground;
- a second high side driver connected to the firing voltage source and a second feed terminal for second squib loop;
- a second low side driver connected to a second return terminal for the second squib loop and the ground;
- a testing current source being connected to source current to the first return terminal for the first squib loop and return current through the second return terminal for the second squib loop;
- a voltage measurement unit configured to measure a voltage between the first return terminal and the second return terminal.
Dependencies are inferred from the claim text.