Design and verification of engine power calculation model using the data of a digital bus built into an agricultural tractor

Abstract

Engine power is a fundamental parameter for determining the utilization of an agricultural tractor. A wrong combination of a tractor and agricultural machinery leads to non-efficient loading of the engine, which causes not only a waste of energy stored in the fuel but also increased financial cost of production. The presented paper focuses on the possibility to calculate engine power from the data, which are available on the digital bus – CAN-BUS. Choosing the appropriate parameters together with the proposed model can help represent the instantaneous power needs. The messages, which provide the basic information about the load, are as follows: engine load, instantaneous torque, instantaneous fuel consumption, engine speed and a set of correction channels. These channels bring the cluster of temperatures and pressures of engine fluids, mainly of the fuel and engine lubricating oil. Without prior determination of the regression function, the data, especially in low load, are very different from the actual torque generated by the engine and measured by a dynamometer. The model represents a function of surface features with a very high index of determination. The model was verified by measuring the power of the engine on a dynamometer. Validation of the model in practice was carried out in the field. The tractor was connected with combined cultivator. The experiment results show a very high statistical match of the results obtained in the laboratory and in field measurements.