Non-linear multi-objective design optimization of a sewing mechanism with joint clearances

Purpose The purpose of this study was to develop a multiobjective design optimization (MDO) of the nonlinear sewing mechanism (SM) behavior responsible for the stitch formation process in a typical sewing machine while considering joint clearances. Design/methodology/approach The nonlinear model of the SM considering clearances in multiple revolute joints was developed. The multiobjective modified imperialist competitive algorithm (MOMICA) was used to investigate the effect of joint clearances on the SM performances. Findings The outcomes showed that SM performance was highly sensitive to the presence of clearances in the joints, which can alter the quality of the stitching process in industrial sewing machines. As an alternative, the MOMICA approach was used to develop a MDO of SM to achieve a proper stitching process and to ensure the most efficient force transmission to the SM needle. The obtained results were discussed, analyzed and compared with those given by the commercialized sewing machine (Juki 8700) with and without joint clearances. Originality/value Although the importance of clearance joint analysis in multibody system behavior has been studied in the past, to date, there has been no study involving the clearing joint during the synthesis and optimization of the sewing machine. The main factor that hinders this analysis is that a system with clearance is nonlinear and time-varying, which is difficult to analyze. The MDO described in this study ensures the trustworthiness and reliability of the SM design, despite the existence of multiple revolute joint clearances.