论文标题
基于CAD的设计优化四杆机制:冠状动脉案例研究
CAD Based Design Optimization of Four-bar Mechanisms: a coronaventilator case study
论文作者
论文摘要
机制的设计优化是一个有前途的研究领域,因为它会导致更节能的机器而不会损害性能。但是,机器构建者实际上并未使用文献中描述的设计方法,因为这些算法需要过多的理论分析。此外,文献中的设计合成方法主要利用启发式优化器,导致次优的局部最小值。 这项研究引入了方便的优化工作流程,可实现广泛的工业采用,同时保证揭示了全球最佳效果。为了确保我们找到全局最佳量,描述可能设计的可行区域的约束的数学表达非常重要。因此,讨论了点对点(PTP)平面四杆机制的运动学分析以获得静态和动态约束。在可行的区域内,客观价值样本是通过CAD多体软件生成的。这些运动模拟确定了所需的扭矩,以实现设计参数一定组合的运动。稀疏的插值技术允许最大程度地减少所需的样品数量,从而最大程度地减少了CAD模拟。此外,这种仿真结果的插值可以在数学描述中表示目标的表示,而无需机器设计人员的深入分析设计分析。随后,该目标的数学表达使全局优化器可以在可行的设计空间中找到全局最佳设计。在具有三个设计参数(DP)的冠状动脉机理的案例研究中,1870 CAD运动模拟,仅使用618个构建模型,以将机制的RMS扭矩降低67%。
Design optimization of mechanisms is a promising research area as it results in more energy-efficient machines without compromising performance. However, machine builders do not actually use the design methods described in the literature as these algorithms require too much theoretical analysis. Moreover, the design synthesis approaches in the literature predominantly utilize heuristic optimizers leading to suboptimal local minima. This research introduces a convenient optimization workflow allowing wide industrial adoption, while guaranteeing to reveal the global optimum. To guarantee that we find the global optimum, a mathematical expression of the constraints describing the feasible region of possible designs is of great importance. Therefore, kinematic analysis of the point-to-point (PTP) planar four-bar mechanism is discussed to obtain the static and dynamic constraints. Within the feasible region, objective value samples are generated through CAD multi-body software. These motion simulations determine the required torque to fulfill the movement for a certain combination of design parameters. Sparse interpolation techniques allow minimizing the required amount of samples and thus CAD simulations. Moreover, this interpolation of simulation results enables the representation of the objective in a mathematical description without in-depth analytical design analysis by the machine designer. Subsequently, the mathematical expression of the objective allows global optimizers to find a global optimal design within the feasible design space. In a case study of a coronaventilator mechanism with three design parameters (DP's), 1870 CAD motion simulations from which only 618 are used to build a model allowed to reduce the RMS torque of the mechanism by 67%.