基于物理属性的虚拟装配过程

针对虚拟装配系统中存在仿真程度不够高的缺点，提出基于物理属性的虚拟装配过程研究。通过分析虚拟装配过程对零部件物理属性的需求，建立零部件物理属性模型，给出确定零部件各物理属性以及自由运动状态的方法，分析碰撞响应对运动状态的影响。研究虚拟装配系统中装配对象间的交互过程，使用多刚体系统动力学分析方法对零部件装配过程中的动力学以及运动学进行分析，给出装配对象的运动学与动力学方程。通过把抽象的约束关系转换为基本约束方程表达运动副约束，并把运动副约束用于装配对象的运动分析。提出基于碰撞与静力学的稳态分析方法研究零部件达到稳定状态的条件。应用实例表明上述方法有效可行。

Physically-based Virtual Assembly Process

In order to improve fidelity for virtual assembly system, research on physically-based virtual assembly process is proposed. Physically-based model for parts and components is created by analyzing the requirement of virtual assembly process on physical property of parts and components. The calculating method of basic physical property is given. Physically-based free motion navigating and collision response is discussed and the method to establish free motion state is given. Interaction process among assembly objects in virtual assembly system and the approach to analyzing local steady status for assembly objects are researched based on analyzing physically-based virtual assembly process. Analysis for dynamics and kinematics in virtual assembly process is committed using multi-body system dynamics and the equations for dynamics and kinematics are presented. Kinematical pair constraint is expressed by using basic constraint equation which is converted from abstract constraint relations. Kinematical pair constraint is used in further kinematics analysis for assembly objects. The steady state analysis approach based on collision and static is given and used to research the conditions for steady state of assembly objects. Application instance manifests that the method mentioned above is feasible and effective.