In recent years the fuel injection technology has taken a great
leap in two-wheeler industries both in terms of having lean
emissions and in terms of improving efficiency. Especially in a
market like India where fuel efficiency is given, as prime
importance and fuel contamination duly exists, it becomes all the
more a bigger challenge to address to these kinds of problems by
some means.
The main function of the fuel system is to make sure right
amount of fuel is injected into the intake manifold at right time
with the help of Electronic Control Unit. Variation from the right
quantity and quality of fuel leads to partial burning and finally
to more emissions and poor performance. So monitoring fuel
pressure, there by the quantity and fuel quality is very much
important to reduce emissions and to achieve desired
performance.
The entire fuel delivery system is split into several sub
systems viz: fuel pump - a PMDC (permanent magnet DC motor) motor
to pressurize the fuel coming out of the fuel tank, fuel regulator
- spring type mechanical regulator to maintain the pressure near to
2.5 bar (2.5*10⁵ Pascal) constant, fuel rail - to hold the
pressurized and regulated fuel for the system and injector - opens
up for the desired quantity of the fuel into intake manifold with
help of engine control unit acting as trigger to it.
In the first phase of this paper, a 1st principles-based
mathematical model of the fuel system is proposed.
This model helps to understand the dynamic behavior of the
system. The work is further extended by developing another dynamic
model using system identification tools. Both the models are
validated with experimental results.
The main aim of this paper is to develop a control-oriented
model, which replicates the behavior of the actual plant. The above
models are compared for the computational efficiency, as one of the
above models will be used for designing different control
strategies in future.