Aiming at the problem that the magnetic levitation ball is difficult to model accurately. This article establishes a control model for the magnetic levitation system by using model free adaptive control method, which reduces the difficulty of constructing mathematical models in previous magnetic levitation systems. And using simulation software and then the experiment was carried out on the GML-2001 experimental platform, the results of the model free adaptive controller and PID controller were compared, and it was ultimately found that the model free adaptive control method has advantages such as dynamic performance, small fluctuation range, and small steady-state error.

针对磁悬浮系统的时滞问题,根据磁悬浮球系统的物理参数建立了单自由度磁悬浮系统的数学模型,分析了磁悬浮球系统的时滞特性,参考规定的相位裕度设计了一种磁悬浮球系统的相位超前校正控制器,采用Matlab/Simulink对相位超前校正控制器与Smith-PID控制器进行了仿真分析,并在磁悬浮球系统实验台上进行了悬浮实验.结果表明,与Smith-PID控制器相比,所设计的磁悬浮系统相位超前校正控制器具有较好的稳态性能与较小的波动范围,能很好地解决磁悬浮系统的时滞问题.

为了提高 Y形管无阀压电泵的流量,基于三叉树的结构特征提出了一种三叉四通管无阀压电泵.模拟分析了三叉四通管的速度流线图,对比了该流管与 Y 形管的阻力特性,制作了 2 种流管的泵样机,进行了流量和压力差试验.研究结果表明:流体在三叉四通管中正、反向流动时均没有产生明显的旋涡,三叉四通管无阀压电泵的效率比 Y形管无阀压电泵提高了 22.69%.在 220 V驱动电压下,三叉四通管无阀压电泵的最大流量为 7.41 g/min,比 Y形管无阀压电泵提升了 21.47%;三叉四通管无阀压电泵的最大压力差为 421 Pa,比Y形管无阀压电泵高出了 79.17%.

针对齿轮范成原理实验采用课堂集中讲授的传统教学模式存在课堂学时不够和教学效果不理想的问题,进行了该实验的混合教学模式设计与研究,通过线上微课视频与师生互动让学生在课前预习时建立对实验的感性认识,通过线下问题引导与知识总结使学生在课堂教学中加深对基本概念的理解.实践表明该混合教学模式不仅大大提高了课堂授课效率,使学生能按时高质量完成实验任务,而且促进了学生对目标知识点的掌握,教学效果得到明显改善.

针对全格式无模型自适应控制(FFDL-MFAC)算法参数难以整定的问题,提出了一种基于增量式PD控制算法的FFDL-MFAC算法参数整定方法.首先通过增量式PD控制算法和FFDL-MFAC算法的相似性,得到PD控制算法的参数KP,KD与FFDL-MFAC算法参数之间的关系,简化FFDL-MFAC算法参数整定的过程;然后以复杂的单自由度磁悬浮系统作为受控对象,验证通过PD算法整定的FFDL-MFAC参数的有效性.仿真结果表明通过PD算法整定的全格式无模型自适应控制器参数能够使被控对象实现稳定悬浮,且加入扰动后可以迅速恢复稳定状态;试验结果表明PD算法整定的全格式无模型自适应控制器相比PD控制器具有更快的响应速度和更强的鲁棒性.

Micro-arc oxidation is a low-cost and environmentally friendly technology for improving the corrosion resistance of magnesium alloys. However, the inherent porous structure limits the application of magnesium alloy micro-arc oxidation coatings in corrosion resistance. Herein, we investigated the corrosion resistance and friction resistance of the magnesium alloy micro-arc oxidation coating after being sealed by hydrothermal treatment and heat treatment. SEM, FTIR, XRD and XPS were performed to investigate the surface morphology and chemical composition of the prepared coating. The potentiodynamic polarization curve and electrochemical impedance spectroscopy confirmed that the prepared sample has good corrosion resistance in 3.5 wt% NaCl aqueous solution. In addition, the samples with coating also exhibit good friction resistance. After friction test, the samples still maintain good corrosion resistance. This method not only promotes the application of magnesium alloys in corrosive environments, but also has great potential for industrial production. (c) 2021 Elsevier B.V. All rights reserved.

research-article Reliability Analysis of Kinematics Accuracy for a Metamorphic Palletizing Robot Mechanism Share on Authors: Huiqing Chen Guilin University of Technology, China Guilin University of Technology, ChinaView Profile , Xianxuan Li Guilin University of Technology, China Guilin University of Technology, ChinaView Profile Authors Info & Claims ICIIP 2021: 2021 6th International Conference on Intelligent Information ProcessingJuly 2021 Pages 267–271https://doi.org/10.1145/3480571.3480619Online:29 October 2021Publication History 0citation13DownloadsMetricsTotal Citations0Total Downloads13Last 12 Months13Last 6 weeks3 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteGet Access

高校实验室安全是学校与社会安全稳定的重要内容之一,也是高校平安校园建设的重要组成部分.文章通过分析高校实验室安全管理现状及存在的问题,从加强安全教育、实行实验室准入制度、建立健全安全管理制度、建立安全责任制、做好防范措施、制订科学合理的应急预案等方面研究高校实验室的安全管理对策,以期有效提高实验室安全管理水平.

通过分析计算机辅助制造课程在传统教学模式中存在的主要问题,提出了以应用实践为导向的教学做三位一体的教学改革思路.通过理论与实验教学的整合,教材原有知识模块的重构创新以及嵌入加工实例场景的互动教学的实施,取得了良好的教学效果,达到了课程的教学目标,为工科应用型课程的教学改革提供了参考.

The valveless piezoelectric pumps with hemisphere-segment bluff-body (HSBB) of different splitting angles (180(, 210( and 240() were designed. The theoretical vibration and flow characteristics of pumps were analyzed in detail. The flow resistance simulation for different pumps were performed by a computational fluid dynamics technique, and the flow resistance performance of positive and negative directions were discussed in terms of interior pressure and velocity distribution contours. The prototype pumps were fabricated by means of 3D printing technology. The experimental results on the flow resistance of prototype pumps suggested that the valveless piezoelectric pump with HSBB of 210( splitting angle exhibited the best flow transportation performance, which is a promising candidate for various flow delivery applications.

Aiming at Magnetic levitation system, the Simulink and Magnet joint simulation method is proposed. The model of magnetic levitation system is built in Magnet. The PID controller is designed in Simulink through the Simulink-Magnet plug-in. The range of KP, KI, KD is computed. The magnetic levitation system is tested and simulated. The experimental simulation results show that the joint simulation control method can realize real-time data exchange between Simulink and Magnet, which greatly improves the efficiency of the experiment. The magnetic levitation model established in the Magnet software can replace the magnetic levitation experiment bench and the cost of purchasing the magnetic levitation test platform is saved. The establishment of the simulation model is flexible. The one or more degrees of freedom magnetic levitation model can be simulated. The test results can be easily viewed and the experimental data can be modified timely. This method can realize the stability analysis of the magnetic levitation system.

This paper selects bias slider-crank mechanism with a constant angular velocity as the research object. First the motion law of mechanism is derived by adopting complex vector method, and then the motion law curve of slider is solved and drawn with MATLAB which can accurately reflect the actual slider motion law; meanwhile output ADAMS simulation result data and compare ADAMS simulation results with the derived results with MATLAB. The results show slider motion law of ADAMS simulation coincides with the theoretical derivation result, which is simulation intuitive and easy to measure.