US 7,107,488 B2Granted

Electronic control unit including monitoring control circuit

AssigneeMitsubishi Denki Kabushiki Kaisha

InventorsKohji Hashimoto, Katsuya Nakamoto

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Abstract

A microprocessor 20a controls an electrical load group 12 responsive to content of a non-volatile program memory 25a and operation state of an input sensor group 11. A monitoring control circuit section 30a sequentially transmits a large number of question items with an inquiry packet, and compares response content from the microprocessor 20a with correct answer information to carry out an error determination. The microprocessor 20a diagnoses an interval of receiving an inquiry packet to monitor in reverse the monitoring operation of the monitoring control circuit section 30a. Thus, in an electronic control unit having a microprocessor built-in, a monitoring control circuit is obtained that alternatively executes at regular intervals a part of control programs to carry out operation inspection during operation.

Claims20

Dependent claims

An electronic control unit having a monitoring control circuit comprising:

a non-volatile program memory, an operation processing RAM memory, an input interface circuit to which an input sensor group is connected, an output interface circuit to which an electrical load group is connected, and a microprocessor controlling the mentioned electrical load group responsive to a content of a control program that is stored in said non-volatile program memory, and an operation state of said input sensor group;
wherein the electronic control unit further comprises:
a monitoring control circuit section that is connected to said microprocessor via a pair of serial interface circuits, and includes inquiry packet transmission means for sequentially transmitting regularly question information to said microprocessor;
correct answer information storage means to said question information;
and error determination means for comparing answer information based on said question information with correct answer information that is stored in said correct answer information storage means to determine presence or absence of any error;
and
under-monitoring processing means that is an under-monitoring processing program stored in said non-volatile program memory in addition to the control program for input/output control, and includes:
simulation-operation-execution processing means that is executed based on the question information having been transmitted by said inquiry packet transmission means;
response packet transmission means for transmitting an execution result of said simulation-operation-execution processing means as an answer information to said monitoring control circuit section;
and receiving interval error processing means that is reverse monitoring means for restarting, or alarming and stopping said monitoring control circuit section when a receiving interval of said inquiry packet is abnormal;
and
wherein, an under-test target program that is contained in said control program and a simulation-operation-execution processing program serving as simulation-operation-execution processing means and contained in said under-monitoring processing program include at least some common programs.

9 more elements

An electronic control unit having a monitoring control circuit comprising:

a non-volatile program memory, an operation processing RAM memory, an input interface circuit to which an input sensor group is connected, an output interface circuit to which an electrical load group is connected, and a microprocessor controlling said electrical load group responsive to a content of said non-volatile program memory, and an operation state of said input sensor group;
wherein the electronic control unit further comprises:
a monitoring control circuit section that is connected to said microprocessor via a pair of serial interface circuits, and includes inquiry packet transmission means for sequentially transmitting regularly question information to said microprocessor;
correct answer information storage means to said question information;
and error determination means for comparing answer information based on said question information with correct answer information that is stored in said correct answer information storage means to determine presence or absence of any error;
and
under-monitoring processing means that is an under-monitoring processing program stored in said non-volatile program memory and includes:
simulation-operation-execution processing means that is executed based on the question information having been transmitted by said inquiry packet transmission means;
response packet transmission means for transmitting an execution result of said simulation-operation-execution processing means as an answer information to said monitoring control circuit section;
receiving interval error processing means that is reverse monitoring means for restarting, or alarming and stopping said monitoring control circuit section when a receiving interval of said inquiry packet is abnormal;
and
a watchdog timer that generates a reset pulse signal when a pulse width of a watchdog signal, being a pulse train that said microprocessor generates, exceeds a predetermined value to restart, or alarm and stop said microprocessor and said monitoring control circuit section;
and
wherein operation of said microprocessor is monitored by said watchdog timer and said monitoring control circuit section, and said microprocessor monitors in reverse monitoring control operation of said monitoring control circuit section.

11 more elements

Dependencies are inferred from the claim text.