Control method and system for opening degree of EGR valve of engine

Abstract

The invention discloses a control method and system for the opening degree of an EGR valve of an engine. A waste gas circulation system of the engine comprises a second pipeline and a first pipeline.The first pipeline is provided with the EGR valve. The method comprises the steps of acquiring a first pressure value of the second pipeline of the engine when a pressure sensor of the EGR valve is ina failure state; comparing the first pressure value with a first preset value; acquiring a second pressure value of the downstream portion of an air filter when the first pressure value is larger than or equal to the first preset value, and taking the second pressure value as an estimation pressure value of the downstream portion of the EGR valve; and determining a pressure value of the downstream portion of a throttle valve when the first pressure value is smaller than the first preset value, and taking the pressure value of the downstream portion of the throttle valve as an estimation pressure value of the downstream portion of the EGR valve. According to the control method and system, the pressure value of the downstream portion of the EGR valve is determined on the basis of the stateof the throttle valve and a pressure value of the upstream portion of the throttle valve, it is guaranteed that the EGR valve makes a right response on the basis of an instruction of an engine controller, and the performance of the whole car is improved.

Description

technical field [0001] The invention relates to the technical field of automobiles, in particular to a method and system for controlling the opening of an engine EGR valve. Background technique [0002] With the development of the economy, the automobile industry has also developed. The increase in the number of automobiles has also caused some problems, such as environmental pollution, energy depletion, etc., especially environmental pollution. Every year, the exhaust gas emissions of automobiles are very large, resulting in certain environmental pollution. [0003] At present, many automobile manufacturers adopt exhaust gas recirculation (Exhaust Gas Recirculation, EGR for short) technology. The exhaust gas is introduced into the intake pipe and mixed with fresh air, and enters the fuel chamber to participate in an emission control technology for combustion; the position of the EGR valve can generate different signals, and the EGR valve transmits the signal to the engine ...

AI Technical Summary

Problems solved by technology

However, the exhaust gas recirculation function of the existing engine mainly relies on the EGR valve sensor to obtain the pressure value downstream of the EGR valve. When the EGR valve pressure sensor fails or the measured value fails, the engine controller cannot monitor the position of the EGR valve. , the timing and duty cycle of opening the EGR valve cannot be controlled, which will seriously cause problems such as unstable engine operation, poor idle speed or other driving performance failures

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