基于Morph网格变形方法的白车身模态优化

白车身模态是影响汽车振动噪声性能优劣的重要因素,在车身CAE仿真设计阶段,白车身模态频率是最为重要的优化指标.以白车身前端横摆模态性能优化为例,通过灵敏度分析确定关键结构位置,利用Morph网格变形方法将关键结构的截面参数化,采用序列二次规划算法进行数值迭代优化;经过12步迭代,白车身前端横摆模态频率提升3.06 Hz,同时1阶弯曲模态、1阶扭转模态和白车身重量3个响应得到了有效的约束控制;结果表明,该方法可以对白车身模态性能实现高效、有针对性的优化设计.     

Diverse traversability mapping using hybrid vision system for lunar rover

Autonomous functions including mapping and path planning are very important to ensure efficient exploration and safe navigation of unmanned rover. Conventional navigation schemes based on equipments such as GPS and magnetic sensors have been proven to be ineffective on lunar surface, while sophisticated dead reckoning approach lacks accuracy in loose soil due to slippage. In this paper, we propose a hybrid vision system (HVS) which consists of one stereo and one omnidirectional vision sensor, attempting to integrate the advantages of diverse vision systems. The hierarchical mapping reconstructs environment through HVS in different resolutions and structures, named qualitative, rough and detailed map. These maps are employed for path planning which navigates the rover towards specified destinations autonomously, avoiding obstacles in its way. The HVS aims at providing more efficient and safe navigation. Simulations and experiments demonstrate the functionality and advantage of our approach.