Supervisory control of complex propulsion subsystems
Doktorsavhandling, 2022
In the first part of the thesis, the focus is on diesel engine application control for emissions and fuel consumption reduction. Model of exhaust emissions in a diesel engine obtained from a combination of nominal engine operation and deviations are evaluated for transient drive cycles. The look ahead information as a trajectory of vehicle speed and load over time is considered. The supervisory controller considers a discrete control action set over the first segment of the trip ahead. The cost to optimise is defined and pre-computed off-line for a discrete set of operating conditions. A full factorial optimisation carried out off-line is stored on board the vehicle and applied in real-time. In a first proposal, the subsystem control of the after-treatment system comprising the lean NOx trap and the selective reduction catalyst is considered. As a next iteration, the combustion engine is added to the control problem. Simulation comparison of the controllers with the baseline controller offers a 1 % total fuel equivalent cost improvement while offering the flexibility to tailor the controller for different cost objective.
In the second part of the thesis, the focus is on cold-start emissions control for modern gasoline engines. Emissions occurring when the engine is started until the catalyst is sufficiently warm, contribute to a significant proportion of tailpipe pollutant emissions. Electrically heated catalyst (EHC) in the three way catalyst (TWC) is a promising technology to reduce cold-start emissions where the catalyst can be warmed up prior to engine start and continued after start. A simulation framework for the engine, TWC with EHC with focus on modeling the thermal and chemical interactions during cold-start was developed. An evaluation framework with a proposed equivalent emissions approach was developed considering the challenges associated with cold-start emission control. An equivalent emission optimal post-heating time for the EHC is proposed that adapts to information which is available in a real-time on-line implementation. The proposed controller falls short of just 1 % equivalent emissions compared to the optimal case.
Look-ahead control
engine control
exhaust after-treatment
supervisory control
Författare
Dhinesh Vilwanathan Velmurugan
Chalmers, Elektroteknik, Signalbehandling och medicinsk teknik
Supervisory Controller for a Light Duty Diesel Engine with an LNT-SCR After-Treatment System
SAE Technical Papers,;Vol. 2018-September(2018)
Artikel i vetenskaplig tidskrift
A simulation framework for cold-start evaluation of a gasoline engine equipped with an electrically heated three-way catalyst
IFAC-PapersOnLine,;Vol. 54(2021)p. 526-533
Paper i proceeding
Evaluation of electrically heated catalyst control strategies against a variation of cold engine start driver behaviour
SAE Technical Papers,;(2022)
Paper i proceeding
Dhinesh Velmurugan, Tomas McKelvey, Jan-Ola Olsson, "Data-driven near-optimal on-line control for an electrically heated catalyst equipped gasoline engine"
This thesis focuses on modeling the exhaust emissions from a combustion engine, formulating a combined equivalent metric and developing a supervisory control approach for simultaneous reduction of energy consumed and exhaust emissions. Modeling exhaust emissions in a diesel engine obtained from a combination of nominal engine operation and deviations are modelled and verified. An equivalent fuel cost for the diesel engine and the after-treatment system, including the lean NOx trap (LNT) and the selective reduction catalyst (SCR), is formulated. A supervisory control approach is proposed for the control of the diesel engine, LNT and SCR when look-ahead predictive information is available.
Cold-start emissions in modern gasoline engines, occurring until the three-way catalyst (TWC) is sufficiently warm, contribute to a significant proportion of tailpipe pollutant emissions. Electrically heated catalyst (EHC) in the TWC is a promising technology to reduce cold-start emissions where the catalyst can be warmed up prior to engine start and continued after start. A simulation framework for the combustion engine, TWC with EHC is developed and an evaluation framework with equivalent emissions is proposed. An equivalent emission optimal post-heating time for the EHC is proposed that adapts to information that is available in a real-time on-line implementation.
MultiMEC - Multivariabla metoder för energieffektiv motorstyrning
VINNOVA (2014-06249), 2015-03-01 -- 2018-12-31.
Styrkeområden
Transport
Ämneskategorier
Energiteknik
Farkostteknik
Reglerteknik
ISBN
978-91-7905-627-8
Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 5093
Utgivare
Chalmers