Multi-objective rapid optimization method for a variable-stroke valve train device

Abstract Raising the maximum valve lift in two-stroke drive mode is key to increasing power output of variable-stroke engine, so limit design train device critical. The multi-objective genetic optimization algorithm NSGA-2 was coupled with single-freedom dynamics model device. A rapid program for constructed Matlab. Two methods explored mode. first optimize rocker structure, and second cam position structure together. results show that has sufficient computational accuracy. collaborative position-rocker arm are more optimal. Under same valve, compared individual contact force reduced by up 285 N. stress 63 MPa through optimization. Compared original case, increase rate obtained optimizing 12.45%, while 12.85%.