Temperature compensated air/fuel ratio controller and method therefor

摘要

The temperature compensated air/fuel ratio controller is used in conjunction with an internal combustion engine. The method includes electronically sensing the oxygen content and the temperature of the exhaust gas generated by the engine. It was discovered that the oxygen content signal varies in a curvilinear manner with respect to the temperature. The oxygen content signal is therefore compensated in both the linear and non-linear signal regions. The compensated oxygen content signal is then used to control the air/fuel ratio of the engine. In a working embodiment, the temperature compensated air/fuel ratio controller utilizes a zirconium oxide oxygen sensor. One type of circuitry designed to compensate the oxygen content signal in both the linear and non-linear signal regions includes, in one embodiment, electronic circuitry that segments the curvilinear function into linear segments and generates a plurality of linear compensatory signals which are added to the oxygen content signal. The compensated oxygen signal is then applied to a PID controller in the control loop of the engine.