In view of a series of problems in the development process of the traditional EMU bogie instability detection system,such as poor design data traceability,low model reusability,difficulty in ensuring the consistency of design information,and lack of overall system design concept,the model-based system engineering(MBSE)is applied to the design of the bogie instability detection system of the EMU in this paper.Based on Arcadia's modeling method,combined with the function definition analysis method,the architecture design of the bogie instability detection system of the EMU is carried out.The architecture model from"black box"to"white box"of its instability detection system is established through four levels of operation analysis,system analysis,logical architecture analysis and physical architecture analysis,and the function is defined and analyzed by identifying the function,expressing the function and evaluating the function.And the logic correctness of the final architecture is verified by means of state machine simulation.The research shows that in the process of designing the structure of the EMU bogie instability detection system,the model established by the MBSE method has good traceability and reusability,and the overall design of the system can be carried out in the early design stage to reduce decision-making risks,has a positive role in promoting the research and development of EMU bogies.
Composite damage failure form is various,the damage failure forms including laminated plate damage,colloid crack extension and interface debonding.To investigate damage of laminates,colloid crack propagation,interface delamination inherent relations among the three kinds of damage failure,the hybrid bending(MMB)fracture finite element model is firstly established by using ABAQUS/Explicit software,by comparing the simulation and experimental results,which proves the accuracy of MMB model.Then,the internal relationship among the three failure modes was studied by combining the Hashin failure criterion,extended finite Element method(XFEM)and cohesive force model(CZM).The results show that the damage of laminates can not only affect the time of interface viscous separation failure,but also affect the crack propagation path in colloid,which provides a certain reference for numerical analysis of the damage problem of composites.
本刊由西北工业大学主办,1981 年创刊,月刊,向国内外公开发行. 本刊是中文核心期刊、中国科学引文数据库(CSCD)核心期刊、中国科技信息研究所选定的科技论文统计源期刊. 1) 本刊刊登的学术论文主要包括:机械科学与技术的理论研究,设计计算,机构分析,实验研究,涉及机械工程的新方法、新工艺、新材料、新设备,CAD/CAM及机电一体化、学科发展前沿的领先成果.
According to the process and characteristics of the gangue sorting,a grasping trajectory planning scheme for the cable-driven gangue sorting robot was proposed.The kinematic model of the cable-driven gangue sorting robot was firstly expounded,and the accuracy of the model was verified by simulation,which provided a basis forjudging whether the trajectory of the end grab conforms to the change rule of the cable length.According to the characteristics of synchronous movement of the gangues and belt conveyor,the position of the gangue bin and the workspace geometric center,the grasping trajectory of the end grab was then planned four sections,namely as start,preparation,gangue grab,and gangue disposal sections.According to the different motion characteristics of the above sections,the S-type velocity curve,quintic polynomial and the combination of both were used to plan the motion of the end grab.The planned trajectory scheme was finally simulated and analyzed.The results showed that the trajectory,velocity and acceleration of the end grab were continuous,the change of cable length was smooth and continuous,and the trajectory parameters determined by the above method could adapt to the different distribution of gangue on the belt conveyor.
针对当前连续型机器人的运动学逆解求解复杂、低效这一问题,提出了一种基于平面圆弧法的运动学建模方法,其具有运动学逆解求解简单、高效的特点.利用该方法在平面内拟合连续型机器人的弯曲运动形状,建立其运动学模型,分析其驱动空间、关节空间和操作空间的映射关系,并描述其工作空间.分析连续型机器人在平面内弯曲形状的几何约束,建立关节空间变量之间的数学关系,降低求解复杂逆运动学问题的难度.对机器人末端执行器的位置和驱动线长度变化曲线进行仿真分析,求解逆运动学的有效解,并研制原理样机进行样机实验,实验表明该运动学模型的正确性以及逆运动学求解方法的有效性.
