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Gas Flow Controller of LPG-Powered Vehicles

01/03/2012 Category: Automotive, Control, Microcontroller, Project, Renesas, Sensor

The Issac LPG Computer II (ILC-II) is a self-adjusting electronic system, designed around the Renesas M16C microcontroller, to control the gas supply (LPG) of vehicles equipped with a Lambda (EGO) sensor and catalytic converter. It can be configured to require no manual adjustments and can automatically adapt to different environmental conditions and use of the vehicle so as to ensure optimum carburation in terms of driving, consumption and emissions.

ILC-II electronically controls the regulation of gas flow enabling the lambda factor to reach the values required at all speeds thanks to 2 electro-mechanical actuators. Both actuators can be uniquely assigned to either control the gas flow at low speeds and/or medium to high speeds.

LPG Controller


The ILC-II main system components are the analogue circuitry, control section and output stage (for switching relays and actuators). A block diagram of the system is shown below. The ILC-II computer processes the signals from the HEGO sensor, ignition or tacho, throttle position sensor (TPS) and holds in memory a lambda sensor tension value corresponding to the stoichiometric mixture that needs to be maintained for every operating condition of the vehicle’s engine

Gas Flow Controller Block Diagram

This all-in-one digital control unit provides an efficient LPG conversion, economical running cost for the motorist, and overall best vehicle engine performance. Feature settings are kept in memory and are configured via a Graphical User Interface (GUI).