## 1 Introduction  
Composite material preforms fabricated through the three-dimensional weaving technology contain fibers oriented in multiple directions and distributed in three-dimensional space. This structure has the advantage of preventing or retarding the propagation of interlayer cracks in the composite material under impact load, significantly improving the lateral performance of the composite material [1; 2; 3]. Therefore, the impact damage tolerance and fracture toughness of three-dimensional weaving composite materials are extremely higher than those of laminated plates [4; 5]. Three-dimensional woven composite materials are suitable for weaving various complex geometric shapes that can be realized by using different weaving methods and varying weaving angles, yarn density and other parameters, without extensive mechanical processing [6]. Currently, depending on the weaving technique they use, weaving machines are mainly divided into two categories: Cartesian weaving machines and three-dimensional rotary weaving machines. Cartesian weaving machines mainly perform two-step weaving, four-step weaving and multiple-step weaving. The woven yarns in the fabric under production run in the thickness direction and are interwoven between layers to form an internal lock between adjacent layers [7]. Benefiting from the braiding technology the use, rotary weaving machines can operate at a higher braiding speed. However, the cross-sectional shapes of the prefractated components that they produce are mostly circular, quadrilateral, I-shaped and branched. In addition, defects are visible in the structure of variable-cross section 3D woven fabrics and branched fabrics for medical therapy such as artificial coronary arteries and blood vessels [8; 9]. At the same time, these weaving methods required huge equipment, long production cycles, a complex forming technology, and high expenses, which are merely convenient in special situations [10; 11; 12; 13]. Traditional weaving techniques are inapplicable to weave small-sized structures. The catheter interventional technology applied in the therapy of blood vessel diseases hasthe advantages of reliability, minimal invasion and safety. It was inspired by the three-dimensional weaving method for small-sized structures. In the rope drive technology, the motor and other drive units are placed externally, which greatly reduces the mass and volume of the system terminal and provides high operation flexibility and strong load capacity. In addition, the external drives can effectively reduce the vibrations of system terminal, greatly improving its operating accuracy [14; 15; 16]. [PERSON] and [PERSON] developed an active catheter with a diameter of 1.2 mm [17]. [PERSON] prepared a titanium-nickel super-elastic alloy (SEA) catheter through laser micromachining. The catheter consisted of titanium-nickel super-elastic alloy (SEA) tubing and silicone rubber tubing, with the silicone rubber tubing covering the outside of the SEA tubing. The outer diameter of the prefabricated, curved active catheter was 0.94 mm, and the inner diameter was 0.85 mm [18]. [PERSON] et al. developed an active catheter bending guidance robot system with an outer diameter of 3.0 mm, an inner diameter of 2.0 mm, and a length of 1000 mm [19]. [PERSON], from the Department of Bioengineering at the University of Utah, developed an active catheter tip for cardiac treatment based on the advantages of rope drive and studied corresponding active control technologies. The diameter of the conduit shell was 1 mm, the rope was stainless-steel wire with a diameter of 0.1 mm, and the conduit material was polytetrafluoroethylene (PTFE) [20]. Since the traditional weaving equipment is generally huge and not suitable for weaving small-sized products, this study adopted a catheter interventional technology to innovatively design a weaving mechanism suitable for braiding in a small space.