Process for calculating the torque of an electronic injection internal combustion engine

A process for calculation of the torque of a four-stroke internal combustion heat engine with electronically controlled injection, the engine being such that a target provided with an indexing reference is integral with a crankshaft and moves in front of a tooth-passage sensor, mounted in fixed position close to the target and delivering a signal to electronic torque-calculating means, said process comprising calculating, on the basis of numerical values representative of the instantaneous duration of passage of each tooth in front of the sensor, a numerical value representative of the projection, on the phase reference line of the teeth corresponding to the origin of the angular periods of the firings, of the amplitude of the alternating component of the instantaneous durations at the frequency of firings in the engine, characterized in that it comprises correcting the defects of the target by:

• distinguishing between the angular intervals (Ti) of the firings of the target relative to the reference;
• assignment of a term (βi) for each angular interval (Ti);
• and at each top dead point:
• recognition of torque conditions corresponding to absence of firing in the cylinders;
• acquisition of the term (βi) under the said conditions of nonfiring by measurement of the engine torque (Ci), which is proportional to the pressure (Pmanifold) in the intake manifold according to the relationship:
• Ci=Kmanifold=α(ΣN+βi)N2
• where N is the engine rpm, K is a proportionality coefficient and α is a constant term;
• calculation of the engine torque (Cgi) delivered during the phase of acceleration of the engine upon each firing, corresponding to each angular interval (Ti), from the term (βi), which is obtained from the equation:
• Cgi=α(ΣN+βi)N2.