Control system of HCCI/SI double-mode harmonization press-combustion engine and method therefor

Abstract

The invention relates to an HCCI / SI dual-mode homogeneous compression ignition engine control system and a control method. The HCCI / SI dual-mode homogeneous compression ignition engine distributed control system based on single-chip microcomputer and CAN bus includes engine management unit, fuel injection ignition control unit, valve train control unit and combustion information collection and analysis unit. The HCCI / SI dual-mode homogeneous compression ignition engine control method adopts the strategy of hierarchical closed-loop management, and divides the entire engine control into three levels: load control, combustion phase control and mechanism control, and the three levels adopt corresponding closed-loop control . The invention takes the load control of the engine as the main line, ensures the stability of HCCI combustion by controlling the combustion phase, and controls each circuit separately to simplify the coupling relationship. This idea of ​​hierarchical closed-loop control is not only clear in structure and easy to implement, but also especially beneficial to improve the robustness of the control system.

Description

technical field [0001] The invention belongs to the technical field of electrical control for the supply of combustible gas mixture or its components in a combustion engine, and in particular relates to a control system and a control method for a HCCI / SI dual-mode homogeneous compression ignition engine. Background technique [0002] Homogeneous charge compression ignition (HCCI) combustion is an increasingly mature combustion method, which combines the advantages of gasoline engines and diesel engines. At present, at home and abroad, direct intake heating, high compression ratio, fuels that are easier to spontaneously ignite, EGR or internal residual exhaust gas are mainly used to achieve HCCI combustion, and the internal exhaust gas recirculation strategy is considered to be the best way to achieve HCCI combustion on four-stroke gasoline engines. most feasible method. The basic idea of ​​internal exhaust gas recirculation to control the HCCI combustion process of gasoline...

AI Technical Summary

Problems solved by technology

In 2001, the U.S. Department of Energy pointed out that there are still 9 major difficulties in the HCCI combustion mode, among which it is clearly pointed out that: problems such as control systems and control methods have yet to be resolved

[0004] At present, the centralized control method is mainly used at home and abroad, and the PC is used as the control unit. The control algorithm used is too complicated, and there is a certain distance from the practicality in terms of real-time and effectiveness.

The control of the dual-mode homogeneous compression ignition engine is more complicated. It is a multi-input and multi-output system, and it has process coupling characteristics, that is, each control variable will affect all controlled variables.

In this case, multivariable control strategies such as decoupling control and model predictive control are generally used, but these control strategies must first figure out the relationship between the control loops and the complex calculation amount

The dual-mode homogeneous compression ignition engine and its combustion process are a very complex system and its process, it is difficult to establish the transfer function between the input and its output, even if the working process of the engine can be used to establish a model, using model predictive control and other controls unit, will inevitably lead to too complicated control calculations. Since the dual-mode homogeneous compression ignition engine is applied in an actual vehicle, the real-time control must be guaranteed. Therefore, at present, the computer is used as the control unit machine control method at home and abroad. It is practical to solve the current HCCI There are still problems such as ignition timing control, variable working condition operation control, and control systems. There is still a certain distance, and it is still in the laboratory research stage.

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