To realize stable forming of the one-sided stitching (OSS) of the composite preform and avoid missing loop

wrong hooking and unstable stitch forming during the process of stitching the preform

the original OSS process is improved

and a wire-pulling mechanism which can realize the stable forming of the trajectory is added. The  mathematical model of the wire-pulling mechanism is established

and the trajectory of the end actuator of the wire-pulling mechanism is simulated and analyzed

which proves the rationality of its design. The working principle of each mechanism of the OSS device is analyzed. By determining the phase differences among the crank angles of the yarn-lifting

yarn-leading

yarn-hooking and wire-pulling mechanisms

the coordination relationship of the four mechanisms of the OSS device is analyzed and planned

and the motion cycle diagram of each mechanism is established

which lays a theoretical foundation for debugging of the OSS device. Finally

multiple controlled OSS experiments were conducted at varying parameters

including preform thickness

stitch pitch

and stitching speed. The result of loop formation rate of 100% proves the rationality and effectiveness of the motion planning

enhances the stability of the OSS trajectory

and thereby ensuring consistent stitching quality of the composite preforms.