协同仿真/设计中存在的三个问题及解决的技术对策

Three radical problems and corresponding technical strategies in collaborative simulation/design

为了完成基于复杂产品虚拟样机技术的协同仿真/设计任务,提出了一种控制模型移植和瞬时工作点线性分析的无缝集成解决方案。利用显式方程建模方法添加控制模型,并与多体系统动力学模型集成,由该模型求解器统一管理并组装成整机模型联立求解。当外包输出时,这种内部集成模型可以构建开环协同仿真,避免了代数循环问题。通过极小的协同步长设置,可控制多体系统动力学模型积分步长不协调所导致的输出偏差。为获得满足控制器设计要求的线性模型,采用了瞬时工作点的线性分析方法,因为准静平衡点对初始速度不敏感。对于曼彻斯特铁路客车标准模型,设计了直线通过垂向稳定的线性二次型高斯问题控制器,并验证了其鲁棒性。

To accomplish collaborative simulation/design based on complex products' virtual prototype technology, a seamless integration solution including migration of control models and linear analysis on transient working points was proposed. Control models were added by explicit-equation modeling method, and integrated with dynamical modelof Multi-Body Systems(MBS). They were managed and assembled into the whole machine model, and were solved simultaneously by MBS's single solver. When wrapped out, these internal-integrated models could form the open-loop co-simulation so as to avoid the algebraic loop. The output errors, caused by MBS's incoherent iterative steps, could be limited due to sufficient-small synchronous step-sizes. In order to obtain the linear model satisfying the controller design requirements, the linear analysis was adopted on transient working points, instead of quasi-static equilibrium point which was not sensitive to initial velocity. For the Model of Manchester benchmark railway passenger vehicle, a robust Linear-Quadratic-Gaussian(LQG) controller was designed and validated for vertical stability on straight tracks.