The solution region methodology for solving the problem of four-bar linkage synthesis with four specified positions was extended to solve the problem of eight-bar linkage synthesis. The processes to build solution regions for synthesizing different types of eight-bar linkages are described, and the methods of building solution regions are divided into five types. First, the synthesis equation is derived, and the curve expressed by the synthesis equation is called the solution curve. Second, the process to build the spatial solution regions from the solution curves is detailed, and a new defect identification method is developed for building the spatial feasible solution region, which is a set of linkage solutions meeting four positions and excluding defects. Finally, linkage solutions that do not meet practical engineering requirements are eliminated from the spatial feasible solution region to obtain the useful spatial solution region. The examples demonstrate the feasibility of the proposed method. The proposed synthesis methodology is simple and easy to program, and provides reference for four specified position synthesis of other multi-bar linkages.

中文翻译：

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4R 链四个指定位置的平面八连杆的溶液区域合成方法

将求解具有四个指定位置的四连杆合成问题的求解域方法扩展到求解八连杆合成问题。描述了用于合成不同类型八连杆机构的解域的构建过程，并将解域的构建方法分为五种类型。首先导出合成方程，用合成方程表示的曲线称为解曲线。其次，详细描述了从解曲线构建空间解域的过程，并提出了一种新的缺陷识别方法来构建空间可行解域，它是一组满足四个位置并排除缺陷的联动解集。最后，从空间可行解区域中剔除不符合实际工程要求的联动解，以获得有用的空间解区域。实例证明了所提出方法的可行性。所提出的合成方法简单且易于编程，为其他多连杆机构的四指定位置合成提供参考。