Control method and storage medium of diesel engine starting fuel quantity ramp based on instantaneous speed

Abstract

The present invention aims to provide a diesel engine starting oil quantity ramp control method and storage medium based on instantaneous rotational speed, and the method is realized by a ramp state machine in an ECU. When the real-time speed of the diesel engine is greater than the ramp start speed threshold, the state is switched to the start state; the starting fuel quantity is ramped up from the initial fuel quantity to the target fuel quantity according to the ramp algorithm of Q1; when the instantaneous engine speed is greater than the transition speed, the current injection The oil quantity is assigned to the transition oil quantity and frozen, as the initial oil quantity of the slope in the transition stage; after the state is switched to the transition state, the starting oil quantity is based on the slope algorithm of Q2, from the transition oil quantity when the state is switched to the idle speed stable oil quantity slope decrease. Beneficial effects: 1. In the initial stage of starting, the misfire caused by the over-concentration of the mixture can be avoided, and the smooth starting of the diesel engine can be ensured. 2. In the transition stage, realize the smooth transition from start to idle speed, prevent the mixture from being too lean and misfire in the transition stage, thereby reducing the HC emission in the transition stage of starting.

Description

technical field [0001] The invention relates to a method for controlling the fuel injection quantity during the starting process of a diesel engine, in particular to a method and a storage medium for ramping control of the starting fuel quantity of a diesel engine based on an instantaneous rotational speed. Background technique [0002] Diesel engines are widely used in all walks of life because of their high thermal efficiency, durability and reliability, and their operating environments are different. The starting strategy of diesel engine should meet the starting performance of diesel engine in different environments, such as cold start, high altitude start and so on. Therefore, environmental conditions such as coolant temperature, intake air temperature and atmospheric pressure are taken into account in the calculation of diesel engine starting oil, so that the diesel engine can start smoothly under different environmental conditions. [0003] The starting process is an...

AI Technical Summary

Problems solved by technology

However, the intake air volume is small during the starting process of the diesel engine, and too rich mixture will greatly increase the HC emission during the starting process of the diesel engine.

In addition, if the amount of starting oil is too large, the speed of the diesel engine will rise sharply at the end of starting, which will affect the adjustment process of idle speed PID

The speed upshoot causes the idle PID to calculate too small fuel volume, which makes the mixer too lean in the transition stage, misfire occurs, and the HC emission performance of the diesel engine deteriorates

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