Torque estimation method for lean-burn natural gas engine

Abstract

The invention belongs to the field of development of automobile electronic software, and discloses a torque estimation method for a lean-burn natural gas engine. The torque estimation method includes the following steps that 1, the ideal firing angle, the ideal gamma and the ideal engine torque under the current rotating speed and load are determined; 2, the actual firing angle efficiency under the current rotating speed and load is determined; 3, the actual gamma relative efficiency under the current rotating speed and load is determined; and 4, the actual engine torque under the current rotating speed and load is determined by integrating the ideal engine torque, the actual firing angle efficiency and the actual gamma relative efficiency under the current rotating speed and load, and the actual engine torque is equal to the product of the ideal engine torque, the actual firing angle efficiency and the actual gamma relative efficiency. The actual firing angle efficiency and the actual gamma relative efficiency are introduced, the actual engine torque can be calculated more accurately, the actual engine torque transmitted by an automatic transmission controller and a vehicle control unit is more precise, and finally the vehicle performance is greatly improved.

Description

technical field [0001] The invention relates to a method for estimating the torque of a lean-burn natural gas engine, which belongs to the field of automotive electronic software development. Background technique [0002] At present, due to the obvious price advantage of natural gas compared with diesel and gasoline, and the emission of natural gas engines is very clean, it is easy to meet the national V emission requirements under lean-burn conditions, so lean-burn natural gas engines are more and more widely used. [0003] For lean-burn natural gas engines, the current traditional engine torque estimation method is to calibrate the actual engine torque under different working conditions on the engine bench, which is used for engine control and to transmit the actual engine torque to the automatic transmission controller and the vehicle. controller etc. However, this torque estimation method has the following disadvantages: [0004] (1) When the actual ignition angle devi...

AI Technical Summary

Problems solved by technology

[0004] (1) When the actual ignition angle deviates from the basic set value, the actual torque of the engine will have a large deviation from the calibration data of the bench;

[0005] (2) When the actual λ deviates from the basic set value, the actual torque of the engine will have a large deviation from the calibration data of the bench;

[0006] (3) The actual torque deviation of the engine caused by (1) and (2) above will have a great impact on the control accuracy of the vehicle and the ride comfort of the vehicle

Especially for vehicles equipped with automatic transmission or hybrid power, the vehicle controller and engine controller use torque as the communication transmission interface, which requires high engine control accuracy. When the actual torque deviation of the engine is too large, it will cause vehicle control The deviation of the required torque sent by the engine controller to the engine controller is too large, which will seriously affect the performance of the vehicle

Images