A novel method for in-cylinder pressure prediction using the engine instantaneous crankshaft torque

Current practices of condition assessment in large marine engines are largely based on the measurement cylinder pressure using external kits, which poses challenges due to sensors synchronisation and durability issues, as well inability perform continuous monitoring. For addressing these challenges, this study aims at developing a novel method solve inverse problem predicting variations all engine cylinders, by Instantaneous Crankshaft Torque (ICT) for internal combustion engines. This is developed considering Initial Value Problem (IVP) technique along with integration direct crankshaft dynamics model incorporating sensitivity parameters stability criteria calculation Lyapunov Exponent (LE) state-of-the-art Nonmonotone Self-Adaptive Levenberg-Marquardt (NSALMN) optimisation algorithm. The tested number case studies different models Weibe sigmoid functions, healthy, degraded faulty conditions. derived results demonstrate adequate accuracy exhibiting maximum error 0.3% prediction mean peak in-cylinder pressure. analysis calculated resulted identification that significantly impact solution, thus providing improved insights selecting settings. renders non-intrusive pressures monitoring feasible, permanently installed shaft power metre sensor higher sample rates.