Torque estimation for combustion engine using nonlinear model

This paper is concerned with combustion engine torque estimation. The information on combustion engine torque can be utilized for improving engine performance, and fuel efficiency. However, commercial cars have no sensor to measure the torque directly, and therefore several types of torque estimation methods based on the crank-shaft angle are studied. Our previous studies are related to an engine torque estimation based on a piston-crank model as an engine structure. However, our previous studies have a problem in that no load torque is considered. In this paper, to develop a more realistic estimation method, an experimental system based on a buggy car is developed, and a more precise engine model including transmission gears is considered. An experimental system for system identification of the physical parameters is also developed. The torque can be estimated based on the derived engine model, and is compared with the measured indicated torque for evaluation of the estimation accuracy.