Exhaust gas recirculation (EGR) control method and control system of diesel engine and based on excess air coefficient

Abstract

The invention relates to an exhaust gas recirculation (EGR) control method and a control system of a diesel engine and based on excess air coefficient. A rotating speed sensor and an accelerator pedal position sensor are utilized to collect rotating speed signals and accelerator signals of the current running engine. The rotating speed signals and the accelerator signals are transmitted to a diesel engine controller, and the optimum excess air coefficient value of the running diesel engine at the moment is obtained by inquiring an excess air coefficient map in the diesel engine controller. A wide-domain oxygen sensor is utilized to collect oxygen content signals in waste gas and input the signals into the diesel engine controller to conduct inquiry in the excess air coefficient map to obtain actual excess air coefficient value. The optimum excess air coefficient value and the actual excess air coefficient value are transmitted to the diesel engine controller to conduct proportional integral derivative (PID) control. An H-axle driver is utilized to control a direct current motor used for driving an EGR valve to act to rotate in positive and negative direction and control rotating speed of the motor to enable the actual excess air coefficient value to approach the optimum excess air coefficient value, achieve waste gas recirculation and achieve ideal running state.

Description

technical field [0001] The invention relates to an exhaust gas recirculation (EGR) system and a control method, in particular to a diesel engine EGR control method and control system based on excess air coefficient. Background technique [0002] As the main power source of internal combustion engine vehicles, diesel engine has the characteristics of high thermal efficiency, large low-speed torque, good durability and reliability, and its utilization rate is getting higher and higher. However, with the continuous improvement of people's awareness of environmental protection, the harmful emissions of diesel engines have attracted much attention to the harm to human health and the environment. With the improvement of emission regulations in various countries in the world, the limit value of diesel engine emissions is also continuously reduced. In order to achieve the emission target and reduce emission pollution, many methods have been studied. Such as pre-treatment technology...

AI Technical Summary

Problems solved by technology

However, this EGR rate-based EGR control method cannot reflect the gas components contained in the exhaust gas, and cannot truly reflect the state of the mixture gas during combustion in the cylinder; Realized, it cannot be applied to the actual driving vehicle; at the same time, the open-loop control of the EGR rate is performed, and the emission of harmful pollutants in the transient working condition deteriorates

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