Torque ratio concept for combustion phasing detection of a spark ignited engine
This paper presents a method for estimating combustion phasing of a five cylinder, four stroke, spark ignited engine, equipped with a crankshaft based torque sensor. A new measure for combustion phasing based on the torque signal is derived for a single cylinder engine. The measure is called 50% torque ratio. A validation of the measure is done by comparing to the related cylinder pressure based 50% pressure ratio measure. A method is also presented to apply the torque ratio measure to a multi-cylinder engine. A physical model for the instantaneous torque measurement is described handling the torque contributions from all individual cylinders in all combustion phases. The torque contribution from the combusting cylinder is isolated and analyzed by the torque ratio method to find the combustion phasing. The multi-cylinder algorithm is validated on torque and cylinder pressure data from a five cylinder Volvo V70 engine.
Estimation of Combustion Information by Crankshaft Torque Sensing in an Internal Combustion Engine
Future emission regulations for internal combustion engines as well as a strive to reduce CO2 emissions has lead to an increasing interest in control of the combustion process in order to maximize efficiency while keeping the emission levels at a minimum. One possibility to indirectly measure the combustion process quality is by using a crankshaft mounted torque sensor. A signal processing technique is outlined which provides estimates of the gas torque from individual cylinders based on data from a crankshaft mounted torque sensor. The estimates are used for closed loop ignition timing control for the purpose of maximizing engine efficiency. Results from three tests are reported and the presented technique results in a reduced fuel consumption.
Reciprocating Machinery Dynamics: Design and Analysis
Vibration theory fundamentals classification and construction of reciprocating machines the crankshaft and associated components crank mechanism devices balancing of periodic inertia and gas pressure loads torsional vibrations flexural vibrations advanced analytical methods vibration measurement and balancing applications from computational field dynamics pressure pulsations in compressors and pumps reciprocating machinery dynamics and noise design optimization computer programs illustrating case histories.