In this paper, a hierarchical optimization strategy for an ambulance with a supine human body model is proposed to improve suspension performance, where the ride comfort of both patients and paramedics and the road holding of the ambulance vehicle are particularly focused. An ambulance model integrating a hydraulically interconnected suspension system and a stretcher-human body model is developed first. This integrated model considers the interaction between stretcher and human body and provides a platform to directly evaluate ride comfort of patients. The sensitivity stratification concept is defined and the sensitivity levels of each design variable are determined according to sensitivity ratios. Then, design variables and optimization objectives are divided into two pairs and optimized in sequence, which not only comprehensively considers the overall performance of patients and paramedics, but also reduces the number of objectives in each optimization process. At last, the optimum solution of proposed hierarchical strategy is obtained and compared with general monolayer optimization strategy. The simulation results show that the hierarchical strategy is highly competitive and outperforms the monolayer optimization strategy, being able to provide not only a better solution and convergence but also has good computational efficiency.

在本文中，提出了一种具有仰卧人体模型的救护车的分层优化策略，以提高悬架性能，特别关注患者和护理人员的乘坐舒适性以及救护车的抓地力。率先研制出集成液压互联悬挂系统和担架-人体模型的救护车模型。该集成模型考虑了担架与人体之间的相互作用，并提供了一个直接评估患者乘坐舒适度的平台。定义敏感性分层概念，并根据敏感性比确定每个设计变量的敏感性水平。然后，将设计变量和优化目标分成两对，依次优化，不仅综合考虑了患者和护理人员的整体表现，而且减少了每个优化过程中的目标数量。最后，得到了所提分层策略的最优解，并与一般的单层优化策略进行了比较。仿真结果表明，分层策略具有很强的竞争力，优于单层优化策略，不仅能够提供更好的解决方案和收敛性，而且具有良好的计算效率。