Abstract: Using vector algebra and rotational transformation matrices, a mathematical model of arbitrary link trajectory curves for RRSS spatial mechanisms was established. A solution program was developed using MATLAB, a language suitable for solving this model, and the solution results were supplemented with 3D graphical simulation, realizing the automatic generation of link curve atlases for this spatial mechanism. Two examples are given at the end. This research is of great significance for promoting the application of this spatial mechanism in mechanism selection and mechanical motion scheme design. Keywords: RRSS mechanism, spatial link curve, mathematical model, MATLAB language Introduction When realizing point trajectories using planar linkage mechanisms, the link curve atlas-aided design method is well-known to many engineering designers [sup][1-3][/sup]. In contrast, although spatial closed-loop mechanisms have a compact structure and can achieve more complex and diverse trajectories with a small number of links [sup][4-6][/sup], the design model inevitably contains a large number of matrix operations, making the solution difficult, and the solution results lack geometric intuition, which even professional mechanical designers find challenging. With the popularization of computers, the computational difficulties have been resolved, but imagining 3D spatial trajectories solely from the calculation results remains challenging. Therefore, choosing the MATLAB software platform, which is matrix-oriented and has powerful graphics processing capabilities, to develop a trajectory simulation program for spatial closed-loop mechanisms will undoubtedly be more effective in promoting the widespread application of spatial closed-loop mechanisms. This paper establishes a general mathematical model of the link curves of a spatial RRSS mechanism and develops a program using MATLAB to solve this mathematical model, realizing the automatic generation of link curve diagrams for the RRSS spatial mechanism. This is of great significance for promoting the application of this spatial mechanism in mechanism selection and mechanical motion scheme design. To view the original text, please click to download: Automatic Generation of Link Curve Diagrams for RRSS Mechanisms.pdf