有机硅/碳氢表面活性剂对水成膜灭火剂性能的影响

针对目前水成膜灭火剂中表面活性剂存在环境危害的问题,选择性能优良、环境友好型表面活性剂,制备水成膜灭火剂,并对添加表面活性剂的灭火剂性能进行测试。结果表明,有机硅表面活性剂十二烷基二甲基甜菜碱（BS-12）与双性型碳氢表面活性剂椰油酰胺丙基甜菜碱（CAB）在复配后具有较为良好的性能,起泡能力较高,泡沫稳定,铺展迅速,灭火时间短。     

建筑给排水设计与施工配合的研究

通过对建筑给水排水工程中设计与施工配合及交工后用户使用意见反馈的几个问题进行分析,提出解决方法,力求使建筑给排水工程设计更加完美.包括管道、管材、管径的选择,管件的安装与合理使用,以及在设计施工中给排水专业与其它专业相互配合时应注意的细节等.     

动カ调谐陀螺键合图建模及控制方法研究

键合图方法是一种统一处理多种能量范畴的工程系统的动态分析图形化方法。本文根据陀螺的结构原理建立了动力调谐陀螺的开环键合图模型,模型能够正确反映陀螺的特性,根据模型设计了陀螺的再平衡回路闭环解耦控制器,应用20-sim软件对结构和控制一体的陀螺闭环模型进行了仿真,仿真结果表明设计的闭环解耦控制器能够显著降低动力调谐陀螺两轴之间的固有耦合作用,结构和控制一体化的建模和仿真方法有利于实现陀螺控制系统的快速设计。     

数字伺服控制系统软件模块化设计

基于TI TMS320LF240x的DSP数字伺服控制系统软件模块化设计,通过改进控制系统信号流图,以输入输出模块组成信号流图模块.数字伺服控制软件模块与信号流图模块对应,每个模块框代表同名软件模块函数且各模块的输入输出端对应软件函数变量.模块间的连接表示数据流向,用C可调用汇编函数将其数据写入软件模块.     

数字孪生十问:分析与思考

当前数字孪生备受学术界、工业界、金融界以及政府部门关注。然而各界对数字孪生存在不同的理解和认识,对数字孪生相关新概念、新名词、新技术之间的异同存在疑惑,并且对是否适用数字孪生存在决策困惑。为理性和正确看待数字孪生,笔者团队于2019年7月27日在“第三届数字孪生与智能制造服务学术会议”上做了“数字孪生十问:分析与思考”同名题目学术交流报告,对有关问题和国内学者进行了交流讨论。为进一步了解数字孪生国内外学术研究现状,在相关报告内容及思考基础上,首先从时间分布、国家分布、来源出版物分布、研究机构和学者分布、高频关键词分布等不同维度,对2019年12月31日前发表的数字孪生学术论文进行了统计分析。在此基础上,进一步对当前各界关注的①何为数字孪生?②谁在关注数字孪生?③数字孪生:中、美、德,谁更热?④数字孪生与智能制造的关系是什么?⑤数字孪生能否与新一代信息技术(New IT)融合?⑥数字孪生是否存在科学问题?⑦数字孪生何用?⑧数字孪生适用准则是什么?⑨数字孪生是否需要标准?⑩数字孪生是否需要商业化工具/平台?十个问题进行了深入分析与思考,以期抛砖引玉,为研究者更好理解数字孪生,为决策者理性和正确对待数字孪生,为实践者更好落地应用数字孪生提供参考。     

表面活性剂复配对泡沫灭火剂灭火性能的影响

将有机硅表面活性剂十二烷基二甲基甜菜碱分别与离子、两性表面活性剂进行复配,通过实验测试分析不同的复配体系对灭火性能的影响。结果表明,十二烷基二甲基甜菜碱与十二烷基硫酸钠复配后的溶液具有较长的析液时间、良好的铺展性能及较好的灭火性能。     

导引头光电稳定系统稳定精度在线测试调整方法研究

针对弹体扰动对导引头光电稳定系统视轴稳定性的影响,对影响导引头光电稳定系统稳定精度的因素进行了分析,建立了稳定回路模型。基于在线半实物仿真思想,利用dSPACE系统,设计了光电稳定系统视轴稳定精度的测试系统。采用该系统对某光电稳定系统视轴稳定精度进行了测试,并对稳定回路控制器进行在线调整。该方法使设计的光电稳定系统满足了其稳定精度要求,获得比传统方法更高的效率。     

Prestiction friction compensation in direct-drive mechatronics systems

LuGre model has been widely used in friction modeling and compensation. However, the new friction regime, named prestiction regime, cannot be accurately characterized by LuGre model in the latest research. With the extensive experimental observations of friction behaviors in the prestiction, some variables were abstracted to depict the rules in the prestiction regime. Based upon the knowledge of friction modeling, a novel friction model including the presliding regime, the gross sliding regime and the prestiction regime was then presented to overcome the shortcomings of the LuGre model. The reason that LuGre model cannot estimate the prestiction friction was analyzed in theory. Feasibility analysis of the proposed model in modeling the prestiction friction was also addressed. A parameter identification method for the proposed model based on multilevel coordinate search algorithm was presented. The proposed friction compensation strategy was composed of a nonlinear friction observer and a feedforward mechanism. The friction observer was designed to estimate the friction force in the presliding and the gross sliding regimes. And the friction force was estimated based on the model in the prestiction regime. The comparative trajectory tracking experiments were conducted on a simulator of inertially stabilization platforms among three control schemes： the single proportional-derivative （PD） control, the PD with LuGre model-based compensation and the PD with compensator based on the presented model. The experimental results reveal that the control scheme based on the proposed model has the best tracking performance. It reduces the peak-to-peak value （PPV） of tracking error to 0.2 mrad, which is improved almost 50% compared with the PD with LuGre model-based compensation. Compared to the single PD control, it reduces the PPV of error by 66.7%.