A novel robust control system to reduce the exhaust emission and enhance the fuel economy for spark ignition engines Academic Article uri icon


  • It's been many years since the invention of the internal combustion engine. These engines are getting more challenging due to the concerns of ever increasingly harmful pollutions and limited energy sources. Environmental regulations have been more restrictive, and car manufacturers have invested more into reducing emitted pollutions and fuel consumption. It is well recognized that for spark ignition (SI) engines, the air-fuel ratio (AFR) is by far the most dominant factor in determining the engine exhaust gas mixture and the amount of lit/km characteristics. For many years this has been partially addressed due to the restrictions on the control approaches because of existence of a time delay in the control input. The control approach presented in this research provides a novel strategy based on the internal dynamics of SI engines. It compensates for the delay at each instant and follows the desired trajectory of AFR. This leads to a reduction of fuel consumption and keeps the actual AFR close to the stoichiometric AFR, which indeed minimizes the harmful pollutants. The research proposes a thorough design methodology that circumvents the previous limitations for industrial PID controllers in terms of noise attenuation. It is robust against canister purge disturbances, modeling uncertainties, parameter variations and time-varying engine operating conditions. The proposed controller has been implemented on experimental data collected at University of Houston on a FORD F-150 truck. The results have shown considerable improvements over the baseline controller and exhibited excellent performance for the noisy outputs of the sensor due to the aging factors.

author list (cited authors)

  • Tafreshi, R., Ebrahimi, B., Mohammadpour, J., Franchek, m., Grigoriadis, K., & Masudi, H.

publication date

  • January 1, 2012 11:11 AM