EP0170920A2
Expired / Lapsed
EP
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Engine control apparatus
Assignee: Hitachi Ltd
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Filing: 1985-07-10
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Granted: —
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Expires: 2005-07-10
Abstract
Abstract A main computer (2) which furnishes main engine control signals to initiate a predetermined operation of an internal combustion engine, outputs a monitoring signal whose state changes between a high and a low levels at predetermined intervals. The monitoring signal is watched by a main computer monitor (26), which maintains its output at a high level during repetition of the change of state in the monitoring signal and, in absence of the change of state in the monitoring signal, changes the state of its output between the high and a low levels at intervals longer than that of the monitoring signal. A backup computer (28) which furnishes auxiliary engine control signals to initiate the minimum operational condition of the engine, monitors the output of the main computer monitor (26) to detect a malfunction or abnormal operation of the main computer. When the number of the changes of state in the output of the main computer monitor (26) exceeds a predetermined value, the malfunction of the main computer (2) is judged to be serious so that the backup computer (28) provides a switching request signal. Under the condition of existence of the switching request signal and that the backup computer (28) is properly operating, switching from the main computer (2) to the backup computer (28) takes place.
Inventors
- 👤 Shoji Sasaki
- 👤 Kenji Tabuchi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 18:32
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/22; F02D41/24; F02D41/26; F02D41/266; G; G05; G05B; G05B9/00; G05B9/02; G05B9/03
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
242 words
A control apparatus for internal combustion engines having sensing means (6, 8, 32) for providing signals of engine operating parameters representative of operational condition of an internal combustion engine; a first computer (2) which furnishes main engine control signals in dependence on the engine operating parameter signals and produces a monitoring signal indicating the operational condition of the first computer (2); a second computer (28) for outputting auxiliary engine control signals by which the engine is to be controlled during malfunction of the first computer; actuating means (18, 20, 22) receiving either the main or the auxiliary engine control signals to initiate a predetermined operating of the engine; a first computer monitor (26) receiving the monitoring signal to produce a malfunction detecting signal when the malfunction of the first computer (2) is detected from the monitoring signal; and a switching circuit (24) for switching signals to the actuating means from the main to the auxiliary engine control signals when the malfunction detecting signal is produced, chacracterized in that the second computer (28) receives the malfunction detecting signal to furnish a switching request signal and produces a second monitoring signal representing the operational condition of said second computer (28), and that there is provided a switching signal generator (30) which outputs a switching signal to said switching circuit (24) under existence of the switching request signal and the second monitoring signal representative of being under the normal operation of the second computer (28).
Claim 2
Dependent Claim
242 words
A control apparatus for internal combustion engines having sensing means (6, 8, 32) for providing signals of engine operating parameters representative of operational condition of an internal combustion engine; a first computer (2) which furnishes main engine control signals in dependence on the engine operating parameter signals and produces a monitoring signal indicating the operational condition of the first computer (2); a second computer (28) for outputting auxiliary engine control signals by which the engine is to be controlled during malfunction of the first computer; actuating means (18, 20, 22) receiving either the main or the auxiliary engine control signals to initiate a predetermined operating of the engine; a first computer monitor (26) receiving the monitoring signal to produce a malfunction detecting signal when the malfunction of the first computer (2) is detected from the monitoring signal; and a switching circuit (24) for switching signals to the actuating means from the main to the auxiliary engine control signals when the malfunction detecting signal is produced, chacracterized in that the second computer (28) receives the malfunction detecting signal to furnish a switching request signal and produces a second monitoring signal representing the operational condition of said second computer (28), and that there is provided a switching signal generator (30) which outputs a switching signal to said switching circuit (24) under existence of the switching request signal and the second monitoring signal representative of being under the normal operation of the second computer (28).
Claim 3
Dependent Claim
27 words
An engine contro apparatus as defined in claim 1, wherein the first computer (2) is tried to initiate the restart of operation by the malfunction detecting signal.
Claim 4
Dependent Claim
77 words
An engine control apparatus as defined in claim 2, wherein an input/output circuit (4) is further provided through which the transmission of the engine operating parameter signals between said first computer (2) and the sensing means and of the computed data to the switching circuit (24) is conducted, and wherein the input/output circuit (4) is reset by the malfunction detecting signal to produce such a signal as to bring the operation of the engine to a stop.
Claim 5
Dependent Claim
102 words
An engine control apparatus as defined in claim 2 or 3, wherein the monitoring signal of the first computer (2) is a signal which repeats its change of state periodically at predetermined intervals, and the malfunction detecting signal is a signal capable of taking states of two values, which is maintained at one of the states during repetition of the change of rate in the monitoring signal of the first computer (2) and, in the absence of repetition, repeats the change of state between the two states periodically at intervals longer than those of the monitoring signal of the first computer (2).
Claim 6
Dependent Claim
40 words
An engine control apparatus as defined in claim 4, wherein the second computer (28) furnishes the switching request signal when a predetermined number of repetitions of the change of state in the malfunction detecting signal occurs within a certain time.
Claim 7
Dependent Claim
27 words
An engine control apparatus as defined in claim 4, wherein the change of state in the malfunction detecting signal is stopped when the switching signal is generated.
Claim 8
Dependent Claim
48 words
An engine control apparatus as defined in claim 1, wherein there is further provided a second computer monitor (36) which monitors the second monitoring signal and, when the malfunction of the second computer (28) is detected, tries to initiate the restart of operation of the second computer (28).
References Cited (Backward Citations)
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