Engine Torque Estimation Method Based on Ion Current

Abstract

The invention discloses an engine torque estimation method based on ion currents. The method mainly includes the steps of 1, acquiring cylinder pressure through engine rack experiments, and calculating engine indicated torque; 2, analyzing the relationship of ion current signals and the indicated torque; 3, calibrating a loss torque factor; 4, acquiring effective torque of the engine, namely calculating the indicated torque of the engine according to acquired ion current signals and a fitting function of the ion current signals and the indicated torque at first, then calculating loss torque of the engine according parameters of the engine, and acquiring an effective torque estimated value, namely the difference between the indicated torque and the loss torque of the engine, of the engine. According to the method, the torque of the engine is calculated through the ion currents, torque sensors and cylinder pressure sensors are omitted, cost is lowered, and the problem that sensors are difficult to mount is solved.

Description

technical field [0001] The invention belongs to automobile control technology, in particular to an ion current-based engine torque estimation method. Background technique [0002] The hybrid electric vehicle energy management strategy coordinates the work of the engine and the electric motor, and controls the power output, which is the focus of research in the field of hybrid electric vehicle control. At present, the energy management of parallel hybrid electric vehicles is mainly based on torque or power control. Power-based control will be affected by changes in the engine and motor speed during power distribution, while torque control only needs to consider the engine and motor. The torque demand during state switching is relatively simple. In the energy management strategy of HEV based on torque control, the torque of the engine needs to be estimated first during the coordinated control. [0003] At present, the main methods to obtain the engine output torque are: (1) ...

AI Technical Summary

Problems solved by technology

The installation of the torque sensor requires major changes to the vehicle, and the torque sensor is expensive; the torque reconstruction algorithm based on the instantaneous speed of the engine crankshaft is complex, and the requirements for the measurement results of the instantaneous speed of the crankshaft are high, and the requirements for the system software and hardware are high. ; The use of cylinder pressure sensors is expensive, poor in durability, and limited by the installation space of the engine, it is difficult to directly install the sensor on the engine to perform control tasks

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