Method and system for recognizing the readiness for operation of an oxygen measurement sensor
AssigneeVDO Adolf Schindling AG
InventorsThomas Blumel, Harald Collonia
Life of this patent
Estimating the term…
Abstract
A method for detecting the readiness for operation of an oxygen measurement sensor which is located in the exhaust pipe of an internal combustion engine and serves, together with a regulating device, to regulate the preparation of the mixture for the internal combustion engine. The voltage present at the oxygen measurement sensor is measured in succession for two different conditions of load and the internal resistance is calculated from the results of the measurement and compared with a predetermined value.
Claims14
A method for recognizing the readiness for operation of an oxygen measurement sensor which is located in an exhaust pipe of an internal combustion engine and, together with a regulating device, serves to regulate the preparation of a fuel-air mixture for the internal combustion engine, comprising the steps of
- measuring the voltage present in the oxygen measurement sensor in succession for two different conditions of load,
- calculating the internal resistance from the measurement results;
- and
- comparing the calculated internal resistance with a predetermined value.
A system connectable to a fixed source of voltage having a first terminal and a second terminal for determining a state of readiness for operation of an oxygen measurement sensor, comprising
- an oxygen measurement sensor having a first terminal and a second terminal;
- a resistor;
- a switchable voltage source energizable by the fixed voltage source, said first sensor terminal being connectable to the first terminal of said fixed source of voltage, said second sensor terminal being connected via said resistor to said switchable voltage source;
- a microcomputer for operating said switchable voltage source to switch between levels of voltage;
- and
- an analog/digital converter connected between said second sensor terminal and said computer for inputting a voltage thereto.
A circuit for obtaining a state of readiness of an oxygen measurement sensor, comprising
- a microcomputer and a switch controllable by the microcomputer;
- a first resistor, said oxygen measurement sensor, and a series circuit of a second resistor and said switch being connected in parallel;
- and
- an analog-to-digital converter associated with the microcomputer, an input terminal of the converter being connected to the oxygen measurement sensor.
Dependencies are inferred from the claim text.