Co-simulation Study On Continuous Variable Cam Phasing System

Energy and environmental issues are the major factor which influence our automobile industry, especially the increasingly stringent emission regulations which made the world each big carmakers raised a new technology revolution and competition. Internal combustion engine, as the core component of automobile engine power sources, are heading for electric and variable parameter direction. Continuous variable cam phaser(CVCP) can satisfy the different phase demand at different engine conditions, which can improve engine power, economy and emission performance.After referring to the related literature at home and abroad, this paper takes the phaser performance as the core and study the CVCP structure parameters and operation parameters on the influence of CVCP performance and the CVCP performance on the influence of engine performance with the method of structure and principle analysis, model equivalent built co-simulation and so on.The main research contents of this paper are as follows:(1) Through the analysis of phaser working principle and mathematical model, reveal the similarity of the phaser and the hydraulic cylinder. Based on it, this paper used AMESIM build the phaser model and the body model of oil control valve. Comparatively detailed analysis of the mathematical of magnetic circuit and armature motion, and which are realized in Simulink. This paper used the Stateflow block to model the driver circuit of oil control valve according to the principle of voltage modulation and logical relation. Based on the technology of co-simulation, this paper complete the whole model of CVCP.(2) Through the study of controller parameters influence on the performance of CVCP, it introduced two of the performance evaluation target, and also finish the design of variable P controller and compare with the PID controller with dead zone. On this basis, through the theoretical analysis and the simulation results verified each other prove this model can qualitatively analysis the influence of the related parameters. And then analyzed respectively the pulse frequency and return spring of the oil control valve, the displacement and internal leak of the phaser , the oil temperature and pressure and the engine speed and such like those parameters influence on the phaser performance. It could provide a certain basis for the design and manufacture and practical development of the phaser.(3) This paper used GT-power to build the engine model based on the test data of a certain engine, and combined the CVCP model built before on the Simulink platform to realize co-simulation of the whole engine with phaser. Considering the certain difference of engine model and the practical engine, this paper design the objective function to calibrate the phase desired in engine model, and then pointed out response speed of the phaser influence on the engine performance. At last, this paper study the stability of the phaser influence on the engine with the engine cyclical fluctuations as the index, and then found out the mathematical laws between the two evaluation indexes.