IJER-19-0170.R1 Revised Main manuscript.pdf (1.39 MB)
A crank-kinematics based engine cylinder pressure reconstruction model
journal contribution
posted on 2023-06-09, 19:10 authored by Julian DunneJulian Dunne, Colin BennettA new inverse model is proposed for reconstructing steady-state and transient engine cylinder pressure using measured crank kinematics. An adaptive nonlinear time-dependent relationship is assumed between windowed-subsections of cylinder pressure and measured crank kinematics in a time-domain format (rather than in crank-angle-domain). This relationship comprises a linear sum of four separate nonlinear functions of crank jerk, acceleration, velocity, and crank angle. Each of these four nonlinear functions is obtained at each time instant by fitting separate m-term Chebychev polynomial expansions, where the total 4m instantaneous expansion coefficients are found using a standard (over-determined) linear least-square solution method. A convergence check on the calibration accuracy shows this initially improves as more Chebychev polynomial terms are used, but with further increase, the over-determined system becomes singular. Optimal accuracy Chebychev expansions are found to be of degree m=4, using 90 or more cycles of engine data to fit the model. To confirm the model accuracy in predictive mode, a defined measure is used, namely the ‘calibration peak pressure error’. This measure allows effective a priori exclusion of occasionally unacceptable predictions. The method is tested using varying speed data taken from a 3-cylinder DISI engine fitted with cylinder pressure sensors, and a high resolution shaft encoder. Using appropriately-filtered crank kinematics (plus the ‘calibration peak pressure error’), the model produces fast and accurate predictions for previously unseen data. Peak pressure predictions are consistently within 6.5% of target, whereas locations of peak pressure are consistently within ± 2.7° CA. The computational efficiency makes it very suitable for real-time implementation.
Funding
Adaptive cylinder pressure reconstruction for production engines.; G0297; EPSRC-ENGINEERING & PHYSICAL SCIENCES RESEARCH COUNCIL; EP/E03246X/1
History
Publication status
- Published
File Version
- Accepted version
Journal
International Journal of Engine ResearchISSN
1468-0874Publisher
SAGE PublicationsExternal DOI
Department affiliated with
- Engineering and Design Publications
Research groups affiliated with
- Dynamics, Control and Vehicle Research Group Publications
Full text available
- Yes
Peer reviewed?
- Yes
Legacy Posted Date
2019-10-01First Open Access (FOA) Date
2019-10-01First Compliant Deposit (FCD) Date
2019-09-26Usage metrics
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