Closed Loop Control for Adaptive Lean Limit Operation 780039

Although an engine's lean limit fuel-air ratio may be easily found experimentally, it is difficult to predict accurately due to the influence of speed, load, ambient conditions, ignition characteristics, fuel chemistry, engine wear, etc.
This paper will describe a new closed loop feedback control which adaptively tracks the engine's instantaneous lean limit using only one engine sensor. Test data is presented which indicates the control system response to changes in ignition timing, fuel chemistry, speed, and load. Results from laboratory and field tests indicate a significant improvement over programmed fuel-air scheduling systems, both in fuel economy and exhaust emissions.


Subscribers can view annotate, and download all of SAE's content. Learn More »


Members save up to 40% off list price.
Login to see discount.
Special Offer: With TechSelect, you decide what SAE Technical Papers you need, when you need them, and how much you want to pay.