Optimization of production process parameters for polishing machine tools in crankshaft abrasive belt based on BP neural network and NSGA-II

Abstract To improve the surface roughness (Ra) of the connecting rod journals of crankshafts and reduce polishing time for abrasive belt polishing machines, a method for optimizing the polishing process parameters for connecting rod journals is proposed, combining BP neural network and NSGA-II algor...
Ausführliche Beschreibung

Abstract To improve the surface roughness (Ra) of the connecting rod journals of crankshafts and reduce polishing time for abrasive belt polishing machines, a method for optimizing the polishing process parameters for connecting rod journals is proposed, combining BP neural network and NSGA-II algorithm. Initially, factors affecting the surface roughness are screened, and in consideration of practical production requirements, a five-factor four-level orthogonal experiment is designed. A BP neural network is then used to establish a nonlinear mapping relationship between the polishing process parameters and the surface roughness of the connecting rod journals. The predicted results from the BP neural network are used as fitness values, and the NSGA-II algorithm is employed to obtain the Pareto frontier optimal solution set and the corresponding combination of polishing process parameters.According to the optimization results, the process parameters of the abrasive belt polishing machine model are modified as follows: polishing arm cylinder pressure of 0.8 MPa, rotational axis output speed of 140 rpm, abrasive belt model B with grit size 800#, Coolant type concentration of 9%, and polishing time of 20 s. In comparison to the initial scheme parameters of the abrasive belt polishing machine, this combination of parameters resulted in a 25.2% increase in surface roughness at the connecting rod journal and saved 20% of the polishing time. Through the process parameter optimization method in this paper, it will contribute to improving the production performance of the crankshaft abrasive belt polishing machine, effectively enhancing the surface roughness at the processed connecting rod journal and saving polishing time. Ausführliche Beschreibung