Control of HCCI During Engine Transients by aid of Variable Valve Timings Through the use of Model Based Non-Linear Compensation
2005 (English)In: SAE transactions, ISSN 0096-736X, Vol. 114, no 3, 296-310 p.Article in journal (Refereed) Published
One of the main challenges with the Homogeneous Charge Compression Ignition, HCCI, combustion system is to control the Start Of Combustion, SOC, for varying load and external conditions. A method to achieve this on a cycle-by-cycle basis is to vary the valve timing based on a feedback signal from the SOC of previous cycles. The control can be achieved with two basic valve-timing strategies named the Overlap- and the IVC-method. The Overlap-method works by trapping of residuals while the IVC-method affects the effective compression ratio. In an earlier paper it has been shown that if the two methods are incorporated into one controller, SOC can be controlled in a relatively large operating window although the transient performance was not sufficient. The reason is that the simple PI-controller cannot be made fast enough to cope with the transients without magnifying the cycle-to-cycle variations of the combustion into instability. In this work a model based control system that features a non-linear compensation, based on the inverse of the non-linear function from valve timings to ignition delay, is suggested and evaluated. The results show good transient performance. Control performance from engine tests is reported. A combined engine and control simulation system is used for the development of the control strategies. The simulations are accomplished with a commercial cycle simulation code linked with a commercial control simulation code. The simulations are iteratively verified against engine test data. Engine tests are conducted on a single cylinder engine equipped with a hydraulic valve system.
Place, publisher, year, edition, pages
2005. Vol. 114, no 3, 296-310 p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:kth:diva-6042DOI: 10.4271/2005-01-0131ScopusID: 2-s2.0-84877490120OAI: oai:DiVA.org:kth-6042DiVA: diva2:10626
QC 201006292006-08-092006-08-092014-08-08Bibliographically approved