Patent Document ID: 7818104
Application ID: 12034885
Patent Flag: 1

Claim One:
1. A monitoring apparatus for monitoring an operation state of an internal combustion engine, comprising: an atmospheric pressure obtaining portion that obtains an atmospheric pressure; a learning value calculating portion that calculates an atmospheric pressure learning value based on a record of the atmospheric pressure obtained by the atmospheric pressure obtaining portion; an air amount accumulating portion that accumulates the amount of air drawn into the internal combustion engine for a predetermined period of time from a start of the internal combustion engine; an abnormality determination portion that determines the operation state of the internal combustion engine as being abnormal when the accumulated air amount is smaller than a predetermined reference value corresponding to the atmospheric pressure learning value; wherein the reference value is set in accordance with the atmospheric pressure learning value a comparing portion that compares the number of times the atmospheric pressure learning value has been updated, which corresponds to the degree of learning that the learning value calculating portion has performed for the atmospheric pressure learning value, by the learning value calculating portion with a predetermined threshold, and a reference value setting portion that sets the reference value to a value corresponding to the atmospheric pressure learning value, which is calculated by the learning value calculating portion, when the number of times the atmospheric pressure learning value has been updated by the learning value calculating portion is equal to or larger than the predetermined threshold, and the degree of learning that the learning value calculating portion has performed for the atmospheric pressure learning value.