Design and application of air to fuel ratio controller for LPG fueled vehicles at typical down‑way

摘要

This article presents an investigation of air–fuel ratio (AFR) controllers applied to liquefied petroleum gas (LPG) fuelledvehicles with second-generation LPG kits. When a vehicle is running on a down-way, fuel consumption tends to be richbecause of the increased vacuum in the intake manifold. Therefore, an AFR controller was developed that can work basedon a vehicle’s tilt sensor combined with an oxygen sensor. AFR controllers are employed to regulate injectors to formleaner mixtures. We tested the performance of AFR controller at a typical down-way of 10°, 15°, and 20°. As a result, theAFR controller was able to increase AFR value from an average of 14.5 (without controller) to 15.5–16.2, depending onthe gear position and down-way angle. Furthermore, a greater of road slope was observed to have produced greaterAFR. This AFR controller is very promising to be applied to vehicles operating in mountainous areas.