Three-dimensional assembly process planning is a precondition for achieving full product lifecycle management based on three-dimensional modelling. Information expression and management operations of fixture models are key to three-dimensional assembly process planning systems. To reasonably and efficiently achieve the goal of planning assembly processes with a fixture model, the application of a fixture information model to a three-dimensional assembly process planning system is investigated. First, to manage tooling information, a fixture information model is defined that consists of management information, display information, geometric information, assembly constraints and degrees of freedom. Then, based on the analysis of the degrees of freedom of components and the assembly constraint relationship, a method of solving assembly constraints based on degrees of freedom reasoning is proposed. Finally, by using the method of solving assembly positioning based on geometric constraints, the pose transformation and assembly positioning of parts are achieved. Through the development of a tooling function module, the three-dimensional assembly process planning system is improved. The feasibility of the above method is verified using part of a spacecraft as an example.

中文翻译：

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装配工艺规划系统中夹具的装配算法

三维装配工艺规划是实现基于三维建模的产品全生命周期管理的前提。夹具模型的信息表达和管理操作是三维装配工艺规划系统的关键。为了合理有效地实现用夹具模型规划装配工艺的目标，研究夹具信息模型在三维装配工艺规划系统中的应用。首先，为了管理工装信息，定义了夹具信息模型，该模型由管理信息、显示信息、几何信息、装配约束和自由度组成。然后，基于对零部件自由度和装配约束关系的分析，提出了一种基于自由度推理的装配约束求解方法。最后，采用基于几何约束求解装配定位的方法，实现零件的位姿变换和装配定位。通过开发工装功能模块，完善了三维装配工艺规划系统。以航天器的一部分为例，验证了上述方法的可行性。