Torque estimation method for vehicle engine

Abstract

The invention discloses a torque estimation method for a vehicle engine, which comprises the following steps: first calibrating a parameter in the rate of heat release and a coefficient in torque loss in an off-line mode; and then estimating torque on line, first determining indication torque Ti of the engine, then determining loss torque T of the engine, and obtaining the difference between the indication torque and the loss torque of the engine, namely an effective torque estimation value of the engine. The torque estimation method for the vehicle engine can calculate pressure in a cylinder according to the rate of heat release without a pressure sensor and a torque sensor in the cylinder, reduces cost, and overcomes the shortcomings of installation difficulties of sensors and short effective service life. The torque estimation method for the vehicle engine not only can estimate the torque value of the engine under a stable state according to the rate of heat release, but also can estimate the torque value of the engine under a transient state, and simultaneously can meet higher requirement accuracy under the condition of satisfying real time performance.

Description

technical field [0001] The invention relates to vehicle control technology, in particular to a vehicle engine torque estimation method. Background technique [0002] With the global energy crisis and the continuous deterioration of the environment, energy conservation and environmental protection have become important issues that people need to solve urgently. Due to its good fuel economy and low emissions, hybrid vehicles have become one of the most practical ways to solve energy and emission problems. The control strategy is the key to determine the fuel economy, emission, power and ride comfort of HEVs. Estimating the output torque of the engine in real time is a key problem that must be solved in the development of hybrid electric vehicle control strategies. The method of using torque sensor to directly measure the torque is very expensive, difficult to install on the real vehicle and has a short effective service life; the commonly used method of establishing a graph ...

AI Technical Summary

Problems solved by technology

The method of using torque sensor to directly measure the torque is very expensive, difficult to install on the real vehicle and has a short effective service life; the commonly used method of establishing a graph model relies on the table lookup of test data and can only satisfy the simulation of steady-state conditions ; The method of estimating the engine torque completely according to the physical model of the engine has a complicated model structure and requires a lot of calculations, which cannot meet the real-time requirements in the control application

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