面向电缆虚拟装配仿真的多分支弹簧质点模型

A Multi-branch Mass-spring Model for Virtual Assembly of Cable Harness

针对多分支电缆的柔性特征以及复杂拓扑结构导致的装配仿真困难的问题,提出一种面向电缆虚拟装配仿真的多分支弹簧质点模型,该模型在弹簧质点模型的基础上,通过增加分支点连接多个电缆分支,从而表达具有拓扑结构的电缆,同时考虑电缆的抗弯曲、拉伸以及重力等物理属性;提出经典控制理论与运动学相结合的模型求解方法,使用控制变量法拟合出经验公式来实现电缆装配仿真中的'定长约束',采用定点约束算法实现对电缆的固定与捆扎操作仿真;提出球体层次包围盒构造柔性电缆的碰撞模型,通过细分碰撞模型、剔除冗余碰撞等方法实现了柔性电缆的干涉检测,满足了柔性电缆碰撞检测的效率和精度要求。设计并开发了基于多分支弹簧质点模型的电缆虚拟装配仿真原型系统,并通过实例验证了相关算法的可行性。

The real-time assembly simulation of cables is challenging due to the complex topology and flexibility of cables. A multi-branch mass-spring model is proposed to deal with the difficulties. In which the tense and bending characteristic of cable could be dealt with and the point connecting cable branches are added to help express cable harness with complex topology. A solution combining control theory and kinematics is presented. In the solution an experiential formula is fitted with the help of control variable method to ensure the cable＇s length is same and an arithmetic fixing the position of particular mass points is presented to simulate the deformation when cables are bundled up. In collision detection for cable, spherical bounding box is used to build up the collision model of cable, and the more accurate collision point could be got in real time by dividing the collision model into more accurate expression and eliminating redundant collision. A prototype system based on the multi-branch mass-spring model is develoned, in which assembly simulation of cable is carried out and the key techniques and presented solution are validated.