A bayesian based process monitoring and fixture fault diagnosis approach in the auto body assembly process

The auto body process monitoring and the root cause diagnosis based on data-driven approaches are vital ways to improve the dimension quality of sheet metal assemblies. However, during the launch time of the process mass production with an off-line measurement strategy, the traditional statistical methods are difficult to perform process control effectively. Based on the powerful abilities in information fusion, a systematic Bayesian based quality control approach is presented to solve the quality problems in condition of incomplete dataset. For the process monitoring, a Bayesian estimation method is used to give out-of-control signals in the process. With the abnormal evidence, the Bayesian network (BN) approach is employed to identify the fixture root causes. A novel BN structure and the conditional probability training methods based on process knowledge representation are proposed to obtain the diagnostic model. Furthermore, based on the diagnostic performance analysis, a case study is used to evaluate the effectiveness of the proposed approach. Results show that the Bayesian based method has a better diagnostic performance for multi-fault cases.     

基于SMPA的半挂车自动泊车运动规划方法研究

半挂车辆的非稳定运动学特性为其泊车过程中自主运动规划带来严峻挑战。针对半挂车在多障碍物的静态场景中泊车运动规划算法效率低、结果平滑性差等问题,本文提出了序列式运动规划方法（sequential motion planning algorithm, SMPA）。首先,提出了基于二次规划策略和改进双向快速扩展随机树（bidirectional rapidly-exploring random tree algorithm,Bi-RRT）的初始路径生成方法。然后,结合车辆非完整微分约束下的路径节点可行性判别方法研究,提出基于概率的目标偏向采样策略,提高了采样效率。最后,构建了面向车辆系统控制变量连续性的非线性最优化控制模型,解决泊车换向点的对接问题,提高了泊车轨迹平滑性。仿真结果表明,该方法在多障碍物场景中,规划时间相比Hybrid A~*和Bi-RRT分别降低了86.71%和21.44%,轨迹质量也更具优越性。     

东风变速箱:研发有新品销售有亮点

东风汽车变速箱有限公司今年前三季度，新品销售成为销售的主要增长点，新品贡献度从去年底的0．56％提升到现在的14．6％。整体销售收入也一举扭转连续四年下滑的颓势，前三季度比去年同期增长6．44％。这正如日前东风变速箱公司副总工程师黄建红所言：“供不应求的景象在变速箱公司重现了，最近M系列变速箱等几个新品都卖断货了。”     

东风变速箱打造核心竞争力

自2007年6月以来，东风变速箱公司的新品商品化战役捷报频传，重型系列变速箱已分别在东风内部市场和大型整车厂家批量装配。企业产品的优势从哪里来？具体又表现在哪几个方面？日前，变速箱公司总经理郝义国、研发中心副主任曾少军为记者道出了其中真谛。[编者按]     

面向车身数字化工艺开发的机器人动态碰撞检测算法研究

在汽车行业制造流程快速向"数字化"与"智能化"转型的背景下,制造工艺自动开发技术获得学术与产业界的广泛重视.文章针对车身制造过程多机器人工位中自动化工艺路径的规划问题,提出基于智能化算法的多机器人系统动态碰撞检测与协调路径规划算法.尤其针对动态碰撞检测算法中存在的"隧道效应"导致的计算效率低和准确性不足问题,提出基于分...