×

Internal combustion engine controller with exhaust gas purification catalyst and its deterioration monitoring system

  • US 5,819,530 A
  • Filed: 11/18/1992
  • Issued: 10/13/1998
  • Est. Priority Date: 11/18/1991
  • Status: Expired due to Fees
First Claim
Patent Images

1. A control apparatus for an internal combustion engine having a catalyst for purifying an exhaust gas, comprising:

  • an air flow sensor for detecting a quantity of air taken into said internal combustion engine;

    an idle speed detector for detecting an idle speed of said internal combustion engine;

    first and second oxygen density sensors installed, respectively, upstream and downstream of a catalyst unit for purifying an exhaust gas connected to an exhaust pipe of said internal combustion engine;

    a circuit for normalizing output signals of said first and second oxygen density sensors;

    a memory for storing normalized output signals of said first and second oxygen density sensors, in digital form; and

    a data processor for;

    calculating a correlation coefficient of output signals of said first and second oxygen density sensors by logically combining said stored normalized signals by means of a logical AND function;

    determining a conversion efficiency of said catalyst unit based on said cross correlation coefficient; and

    calculating a fuel injection quantity and feedback controlling a quantity of fuel supplied to said internal combustion engine, based on an output signal of at least one of said two oxygen density sensors.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×