Efficient Computer Simulation Program for a General Class of Mechanical Systems

现有的多体机械系统运动仿真计算机程序对实际系统的执行时间普遍较长，不适合或不方便在设计阶段使用。此外，这些程序没有很好地规定通常涉及平面连杆机构或齿轮机构的公共驱动子系统。一种基于以下认识的动态描述方法：大量机械系统可以被建模为由作为系统的主要环节的机构的开环链或树，以及它们的驱动子系统，它们与主要环节一起总是形成局部的闭合运动学回路。这项研究旨在发展这样一种方法，即通过图形表示概念和运动学分析来识别局部闭合环的独立广义坐标，对主链或树使用高效的递归形式，并从局部闭合环中推导出附加贡献。预计一个用户友好和计算效率高的程序可以从这项研究中演变出来，并可以向公众提供商业用途。该程序可以使机械系统设计人员在设计的各个阶段进行有效的仿真，缩短设计周期，降低设计成本，提高设计质量。

The existing computer programs for simulation of the motion of multi-body mechanical systems generally require excessive execution time for realistic systems and this renders them not suitable or inconvenient for use in design phase. Additionally, these programs do not have good provisions for common drive subsystems which often involve planar linkages or geared mechanisms. A dynamic formulation methodology based on the recognition that a large number of mechanical system can be modeled as consisting of an open loop chain or tree of bodies, which are the primary links of the system, and their drive subsystems, which together with the primary links always form local closed kinematic loops. The proposed research is to develop such a methodology that calls for the identification of independent generalized coordinates for the local closed loop through graph representation concept and kinematic analysis, the use of efficient recursive formalism for the primary chain or tree and the derivation of additional contributions from the local closed loops. It is anticipated that a user-friendly and computationally efficient program can evolve from this research and can be made commercially available to the public. The resulted program can enable mechanical system designers to perform effective simulation in the various design phases to reduce the design turn-around time and the design costs, and to improve the quality of design.