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US 6,334,084 B1Granted
Fail-safe apparatus and fail-safe method for electronic control system
AssigneeUnisia Jecs Corporation
InventorsNorio Moteki, Kenichi Machida
Life of this patent
Estimating the term…
Abstract
Duplex fail-safe systems are equipped for outputting fail-safe control signals when a failure is determined by a read/write diagnosis of a RAM, and the logic for the logic operation performed by one of said systems is set to be reverse to the logic for the logic operation performed by the other system.
Claims15
A fail-safe apparatus of an electronic control system comprising:
- a fault diagnosis device for performing a fault diagnosis of a diagnosis object and setting a fault diagnosis flag denoting whether a fault exists or not;
- a first request flag operation device for operating a first fail-safe request flag denoting whether to request execution of fail-safe process or not, according to a logic operation based on said fault diagnosis flag;
- a second request flag operation device for operating a second fail-safe request flag according to the logic operation based on said fault diagnosis flag, which performs an operation of a fail-safe request flag according to the logic reverse to the logic for the logic operation performed by said first request flag operation device;
- and
- a fail-safe control device for outputting a fail-safe control signal to a control object when at least one of said first and second fail-safe request flags denotes a request for executing fail-safe process.
2 more elements
A fail-safe apparatus of an electronic control system comprising:
- a fault diagnosis means for performing a fault diagnosis of a diagnosis object and setting a fault diagnosis flag denoting whether a fault exists or not;
- a first request flag operation means for operating a first fail-safe request flag denoting whether to request execution of a fail-safe process or not, according to a logic operation based on said fault diagnosis flag;
- a second request flag operation means for operating a second fail-safe request flag according to a logic operation based on said fault diagnosis flag, which performs an operation of a fail-safe request flag according to the logic reverse to the logic for the logic operation performed by said first request flag operation device;
- and
- a fail-safe control means for outputting a fail-safe control signal to a control object when at least one of said first and second fail-safe request flags denotes a request for executing said fail-safe process.
2 more elements
A fail-safe method of an electronic control system comprising the steps of:
- performing a fault diagnosis of a diagnosis object;
- operating a first fail-safe request flag that denotes a request for executing fail-safe process when the flag is set to 1, based on the result of said fault diagnosis;
- operating a second fail-safe request flag that denotes a request for executing fail-safe process when the flag is set to 0, based on the result of said fault diagnosis;
- and
- executing said fail-safe process when at least one of said first and second fail-safe request flags denotes a request for executing the fail-safe process.
2 more elements
A fail-safe method of an electronic control system comprising the steps of:
- operating a fault diagnosis flag denoting whether a fault exists in a diagnosis object;
- operating a first fail-safe request flag denoting whether to request execution of fail-safe process or not, according to a logic operation based on said fault diagnosis flag;
- operating a second fail-safe request flag based on said fault diagnosis flag, according to the logic reverse to the logic for the operation of said first fail-safe request flag;
- and
- outputting a fail-safe control signal to a control object when at least one of the first and second fail-safe request flags denotes a request for executing fail-safe process.
2 more elements
A fail-safe apparatus of an electronic control system comprising:
- a diagnosis circuit for performing a fault diagnosis of a diagnosis object and operating diagnosis flags #FLGRTM and #FLGRTS, which denote that a fault has occurred when set to 1;
- a first OR circuit for outputting a fail-safe request flag #ETCOFF according to an OR operation based on said diagnosis flags #FLGRTM and #FLGRTS;
- a first NOR circuit for outputting a fail-safe request flag #ETCOFF_S according to a NOT-OR operation based on said diagnosis flags #FLGRTM and #FLGRTS;
- a second NOR circuit for outputting a fail-safe request flag #RLYON according to a NOT-OR operation of said fail-safe request flag #ETCOFF and a fail-safe request flag #RLYOFFRQ, which is operated based on a fault diagnosis of a control object and which denotes a fail-safe request when set to 1;
- a first NAND circuit for outputting a fail-safe request flag #RLYON_S according to a NOT-AND operation of said fail-safe request flag #ETCOFF_S and a fail-safe request flag #RLYON_SQ, which is operated based on said fault-diagnosis of the control object and which denotes a fail-safe request when set to 0;
- and
- a first AND circuit for outputting a fail-safe control signal to said control object according to an AND operation of said fail-safe request flag #RLYON and an inverted value of said fail-safe request flag #RLYON_S.
4 more elements
Dependencies are inferred from the claim text.