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Reliability Analysis of Satellite Turntable System under Multiple Operation Modes Based on Multi-Valued Decision Diagrams
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作者 Peng Zhang Zhijie Zhou +2 位作者 Yao Ding Dao Zhao Yijun Zhang 《Journal of Beijing Institute of Technology》 EI CAS 2023年第1期52-68,共17页
As a payload support system deployed on satellites,the turntable system is often switched among different working modes during the on-orbit operation,which can experience great state changes.In each mode,the missions ... As a payload support system deployed on satellites,the turntable system is often switched among different working modes during the on-orbit operation,which can experience great state changes.In each mode,the missions to be completed are different,consecutive and non-over-lapping,from which the turntable system can be considered to be a phased-mission system(PMS).Reliability analysis for PMS has been widely studied.However,the system mode cycle characteristic has not been taken into account before.In this paper,reliability analysis method of the satellite turntable system is proposed considering its multiple operation modes and mode cycle characteristic.Firstly,the multi-valued decision diagrams(MDD)manipulation rules between two adjacent mission cycles are proposed.On this basis,MDD models for the turntable system in different states are established and the reliability is calculated using the continuous time Markov chains(CTMC)method.Finally,the comparative study is carried out to show the effectiveness of our proposed method. 展开更多
关键词 phased-mission systems multi-valued decision diagrams continuous time Markov chains(CTMC) reliability analysis satellite turntable system
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OBSERVER/FILTER STRUCTURE BASED ADAPTIVE FRICTION COMPENSATION FOR HIGH PRECISION TURNTABLE 被引量:3
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作者 王忠山 苏宝库 王毅 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2008年第2期113-120,共8页
Two adaptive friction compensation schemes are developed for a high precision turntable system with nonlinear dynamic friction to handle two types of parametric uncertainties in the friction. Both schemes utilize a no... Two adaptive friction compensation schemes are developed for a high precision turntable system with nonlinear dynamic friction to handle two types of parametric uncertainties in the friction. Both schemes utilize a nonlinear observer/filter structure to compensate for uncertainties in corresponding friction parameters associated with the turntable system. Moreover, in the second scheme, adjustable gains are introduced into the dual nonlin- ear filters and they can be tuned to improve the position tracking performance. In both cases, a Lyapunov-like argument is provided for the global asymptotic stability of the closed-loop system. Simulation results demonstrate the effectiveness of the proposed schemes. 展开更多
关键词 FRICTION wave filters adaptive friction compensation high precision turntable observer/filter structure
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Load-induced error identification of hydrostatic turntable and its influence on machining accuracy 被引量:5
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作者 程强 任伟达 +2 位作者 刘志峰 陈东菊 顾佩华 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第10期2558-2569,共12页
In heavy duty machine tools, hydrostatic turntable is often used as a means for providing rotational motion and supporting workpiece, so the accuracy of turntable is crucial for part machining. In order to analyze the... In heavy duty machine tools, hydrostatic turntable is often used as a means for providing rotational motion and supporting workpiece, so the accuracy of turntable is crucial for part machining. In order to analyze the influence of load-indcued errors on machining accuracy, an identification model of load-induced errors based on the deformation caused by applied load of hydrostatic turntable of computerized numerical control(CNC) gantry milling heavy machine is proposed. Based on multi-body system theory and screw theory, the space machining accuracy model of heavy duty machine tool is established with consideration of identified load-induced errors. And then, the influence of load-induced errors on space machining accuracy and the roundness error of a milled hole is analyzed. The analysis results show that load-induced errors have a big influence on the roundness error of machined hole, especially when the center of the milled hole is far from that of hydrostatic turntable. 展开更多
关键词 machine tool load-induced error geometric error hydrostatic turntable screw theory
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Fault detection of switched linear systems with its application to turntable systems 被引量:1
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作者 Guanghui Sun Mao Wang Xiuming Yao Ligang Wu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2011年第1期120-126,共7页
This paper is concerned with the H∞ fault detection for continuous-time linear switched systems with its application to turntable systems.The solvability condition for a desired filter is established based on the pro... This paper is concerned with the H∞ fault detection for continuous-time linear switched systems with its application to turntable systems.The solvability condition for a desired filter is established based on the proposed sufficient condition.Based on the double channel scheme of the turntable control system,the turntable system can be modeled as a switched system.Finally,by taking the turntable system as a numerical example,the effectiveness of the proposed theory is well validated. 展开更多
关键词 fault detection H∞ performance exponential stability switched system turntable system.
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Research on identifying the dynamic error model of strapdown gyro on 3-axis turntable 被引量:5
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作者 王海 任顺清 王常虹 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2005年第6期630-634,共5页
The dynamic errors of gyros are the important error sources of a strapdown inertial navigation system. In order to identify the dynamic error model coefficients accurately, the static error model coefficients which la... The dynamic errors of gyros are the important error sources of a strapdown inertial navigation system. In order to identify the dynamic error model coefficients accurately, the static error model coefficients which lay a foundation for compensating while identifying the dynamic error model are identified in the gravity acceleration fields by using angular position function of the three-axis turntable. The angular acceleration and angular velocity are excited on the input, output and spin axis of the gyros when the outer axis and the middle axis of a three-axis turntable are in the uniform angular velocity state simultaneously, while the inner axis of the turntable is in different static angular positions. 8 groups of data are sampled when the inner axis is in 8 different angular positions. These data are the function of the middle axis positions and the inner axis positions. For these data, harmonic analysis method is applied two times versus the middle axis positions and inner axis positions respectively so that the dynamic error model coefficients are finally identified through the least square method. In the meantime the optimal angular velocity of the outer axis and the middle axis are selected by computing the determination value of the information matrix. 展开更多
关键词 strapdown gyro dynamic error model harmonic analysis three-axis turntable
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Effect of working parameters on performance characteristics of hydrostatic turntable by using FSI-thermal model 被引量:3
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作者 HU Jun-ping LIU Cheng-pei 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第11期2589-2600,共12页
Effects of working parameters on performance characteristics of hydrostatic turntable are researched by applying the fluid-structure-thermal coupled model.Fluid-structure interaction(FSI)technique and computational fl... Effects of working parameters on performance characteristics of hydrostatic turntable are researched by applying the fluid-structure-thermal coupled model.Fluid-structure interaction(FSI)technique and computational fluid dynamics(CFD)method are both employed by this new model,and thermal effects are also considered.Hydrostatic turntable systems with a series of oil supply pressures,various oil recess depth and several surface roughness parameters are studied.Performance parameters,such as turntable displacement,system flow rate,temperature rise of lubrication,stiffness and damping coefficients,are derived from different working parameters(rotational speed of turntable and exerted external load)of the hydrostatic turntable.Numerical results obtained from this FSI-thermal model are presented and discussed,and theoretical predictions are in good agreement with the experimental data.Therefore,this developed model is a very useful tool for studying hydrostatic turntables.The calculation results show that in order to obtain better performance,a rational selection of the design parameters is essential. 展开更多
关键词 hydrostatic turntable working parameters performance characteristics FSI-thermal coupled model
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Axis intersection measurement of three-axis turntable with two crosshair targets 被引量:3
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作者 任顺清 马广程 王常虹 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2005年第3期250-254,共5页
In order to measure three-axis intersection error, two crosshair targets were fixed in the inner axis frame of a three-axis turntable. Also a theodolite was used to point its telescope to the targets and to measure th... In order to measure three-axis intersection error, two crosshair targets were fixed in the inner axis frame of a three-axis turntable. Also a theodolite was used to point its telescope to the targets and to measure the horizontal angles when three axes were on equi-spaced angle positions. The calculation equations of the axis intersection were deduced from the mounting position of the theodolite, positions of two targets, angular positions of three axes, and the measured horizontal angles with the theodolite. Finally, a practical measurement is carried out on a horizontal three-axis turntable and error analysis is conducted. 展开更多
关键词 Axis intersection three-axis turntable THEODOLITE error separation technology homogeneous transformation
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Coupling Analysis of Moment of Inertia & Dynamic on Optoelectronic Tracking Turntable
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作者 Xu Xiaoming Liu Shuli Gu Guohua 《仪器仪表学报》 EI CAS CSCD 北大核心 2013年第S1期214-218,共5页
With photoelectric tracking system as the research object,based on the theorem of moment of momentum and Euler dynamic equation,Nonlinear biaxial coupling dynamic model of tracking turntable is established.Effects of ... With photoelectric tracking system as the research object,based on the theorem of moment of momentum and Euler dynamic equation,Nonlinear biaxial coupling dynamic model of tracking turntable is established.Effects of moment of inertia coupling,speed coupling and the dynamic coupling between tracking turntable shafts were studied,the analytical relation between them was given in theory.Verify the change trend of theoretical model.And it provides the theory reference and model base,for the future design of the high precision tracking controller And control parameter selection and optimization.In the end,specific measures are made for structure optimization. 展开更多
关键词 Opto-electronic TRACKING turntable MOMENT of INERTIA dynamics COUPLING modeling
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Dynamic error research and application of an angular measuring system belonging to a high precision excursion test turntable
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作者 邓辉宇 王欣利 马培荪 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2006年第2期156-159,共4页
Angular measuring system is the most important component of a servo turntable in inertial test apparatus. Its function and precision determine the turntable' s function and precision. It attaches importance to resear... Angular measuring system is the most important component of a servo turntable in inertial test apparatus. Its function and precision determine the turntable' s function and precision. It attaches importance to research on inertial test equipment. This paper introduces the principle of the angular measuring system using amplitude discrimination mode. The dynamic errors axe analyzed from the aspects of inductosyn, amplitude and function error of double-phase voltage and wavefonn distortion. Through detailed calculation, theory is provided for practical application; system errors are allocated and the angular measuring system meets the accuracy requirement. As a result, the schedule of the angular measuring system can be used in practice. 展开更多
关键词 test turntable angular measuring system dynamic error error model
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An Investigation into the Influence of the Airflow Path on the Convective Heat Transfer for an Eddy Current Retarder Turntable
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作者 Yunfei Liao Jin Liu 《Fluid Dynamics & Materials Processing》 EI 2020年第5期961-977,共17页
In order to improve the convective heat transfer relating to an eddy current retarder,the finite element model has been used to assess the performances of different possible designs.In particular,assuming the steady r... In order to improve the convective heat transfer relating to an eddy current retarder,the finite element model has been used to assess the performances of different possible designs.In particular,assuming the steady running state of retarder as the working condition,flow and temperature fields have been obtained for the rotor.The influence of airflow path on heat dissipation has been analysed,and the influence of the temperature field distribution on the performance of retarder has been discussed accordingly.The results show that when the steady running state of the turntable is considered,the maximum temperature is lower,the level of turbulence flow is mitigated,and the temperature distribution becomes more regular.These factors contribute to improve the heat dissipation ability of the retarder. 展开更多
关键词 Eddy current retarder turntable flow field convection heat transfer
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USB Turntable
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《微型计算机》 北大核心 2007年第09Z期18-18,共1页
USB周边设备可谓无其不有,这部USB-Turntable除了具有USB即插即用的特性.还可以让我们通过电脑来播放33/45转的黑胶唱片.同时如果你喜欢.可以将唱片音乐通过附带的软件轻松地保存到你的电脑上。如果你还保存着心爱的黑胶唱片.真... USB周边设备可谓无其不有,这部USB-Turntable除了具有USB即插即用的特性.还可以让我们通过电脑来播放33/45转的黑胶唱片.同时如果你喜欢.可以将唱片音乐通过附带的软件轻松地保存到你的电脑上。如果你还保存着心爱的黑胶唱片.真的可以买来试试。 展开更多
关键词 USB turntable 即插即用特性 电脑 黑胶唱片
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Light pen whole space coordinate measuring system based on a tracking turntable
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作者 WANG Sen LIU Shugui MAO Qing 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2021年第4期379-389,共11页
Light pen coordinate measuring system(LPCMS)is a kind of portable coordinate measuring technique based on vision metrology.In classical LPCMS,the measuring range is limited to the camera’s field of view.To overcome t... Light pen coordinate measuring system(LPCMS)is a kind of portable coordinate measuring technique based on vision metrology.In classical LPCMS,the measuring range is limited to the camera’s field of view.To overcome this defect,a new LPCMS is designed in this paper to fulfil whole space coordinate measurement.The camera is installed on a turntable instead of a tripod,so that the camera can rotate to track the movement of the light pen.The new system can be applied to large scale onsite measurement,and therefore it notably extends the application of LPCMS.To guarantee the accuracy of the new system,a method to calibrate the parameters of the tracking turntable is also proposed.Fixing the light pen at a stationary position,and changing the azimuth angles of the turntable’s two shafts,so that the camera can capture the images of the light pen from different view angles.According to the invariant spatial relationship between the camera and the pedestal of the tracking turntable,a system of nonlinear equations can be established to solve the parameters of the turntable.Experimental results show that the whole space coordinate measuring accuracy of the new system can reach 0.25 mm within 10 m.It can be concluded that the newly designed system can significantly expand the measuring range of LPCMS without losing too much accuracy. 展开更多
关键词 light pen whole space coordinate measuring system tracking turntable vision metrology parameter calibration homogeneous coordinate transformation matrix
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Analysis and Research on the Load of the Box Girder Locomotive Turntable
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作者 NI Shi-hao 《International Journal of Plant Engineering and Management》 2009年第3期158-163,共6页
The locomotive turntable is an essential device for the steering operation of the railway locomotive. This paper has introduced the structural composition and characteristics of the box girder locomotive turntable, ha... The locomotive turntable is an essential device for the steering operation of the railway locomotive. This paper has introduced the structural composition and characteristics of the box girder locomotive turntable, has ana- lyzed its vertical load, horizontal load and torsional load, and has established a mechanical model for the symmet- rical structure of the box girder locomotive turntable under the action of positive and negative symmetric vertical loads. Furthermore, it has also demonstrated the safe and reliable structural performance of this type of locomotive turntable on the basis of the practical example of a 35 m box girder locomotive turntable. 展开更多
关键词 Box girder locomotive turntable load analysis structural performance
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雷达转台液压系统可靠性影响评价预测研究
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作者 彭国朋 刘圣兰 《自动化仪表》 CAS 2024年第5期107-111,共5页
针对当前雷达液压系统可靠性合理建模及影响评价体系难以构建及评估的现状,以某典型机载雷达转台液压系统为研究对象,提出一种基于危害性分析的可靠性影响评价预测方法。利用模糊判断矩阵以获得指标的权重系数,对可靠性进行建模仿真分析... 针对当前雷达液压系统可靠性合理建模及影响评价体系难以构建及评估的现状,以某典型机载雷达转台液压系统为研究对象,提出一种基于危害性分析的可靠性影响评价预测方法。利用模糊判断矩阵以获得指标的权重系数,对可靠性进行建模仿真分析,从而为准确预测系统的可靠性提供理论支撑。在此基础上,通过对转台液压系统故障原因进行全面梳理,构建了液压系统可靠性影响评价体系。运用Elman网络,结合实证分析对可靠性影响评价模型进行预测,为雷达转台液压系统故障的综合分析提供了整体解决方案。这也为进一步提高雷达液压系统的可靠性提供了合理思路。该研究可为雷达其他分系统可靠性分析提供参考。 展开更多
关键词 可靠性 雷达转台 液压系统 评价预测 ELMAN网络 可靠性建模 影响指标
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考虑多工况的甘蔗收割机回转台轻量化研究
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作者 靳龙 陈波铭 《机械设计与制造》 北大核心 2024年第4期51-55,59,共6页
甘蔗收割机回转台在工作过程中承受过双侧凹坑、转向过坑等工况载荷及扭矩的作用,受力复杂,优化时需要多工况综合考虑。ESO多工况优化方法由于未考虑不同工况间的重要程度,不易获得全局最优解。因此提出一种多目标拓扑优化函数,采用带... 甘蔗收割机回转台在工作过程中承受过双侧凹坑、转向过坑等工况载荷及扭矩的作用,受力复杂,优化时需要多工况综合考虑。ESO多工况优化方法由于未考虑不同工况间的重要程度,不易获得全局最优解。因此提出一种多目标拓扑优化函数,采用带权重的线性加权法协调多个目标函数,构建多工况拓扑优化数学模型,运用层次分析法确定各工况的权重系数,基于inspire软件对回转台进行多目标拓扑优化,从而获得材料的最优分布。优化结果表明:优化后回转台结构最大应力与最大位移均有所下降且满足强度与刚度要求,实现了多目标同时优化。 展开更多
关键词 回转台 多工况 拓扑优化 轻量化设计
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动态病例情景结合快速评估转盘在出血评估技术工作坊中的应用
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作者 陈云 罗太珍 +1 位作者 陈嘉欣 杨淳 《卫生职业教育》 2024年第1期157-160,共4页
目的评价快速评估转盘应用于工作坊的培训模式对提高专科护士出血评估技术的效果。方法选取2022年1—12月在广州某三甲医院妇产科培训基地参加脱产专科培训的65名护士为研究对象,采用随机数字表法分为对照组(n=32)和研究组(n=33)。对照... 目的评价快速评估转盘应用于工作坊的培训模式对提高专科护士出血评估技术的效果。方法选取2022年1—12月在广州某三甲医院妇产科培训基地参加脱产专科培训的65名护士为研究对象,采用随机数字表法分为对照组(n=32)和研究组(n=33)。对照组在基于临床真实改编案例的工作坊进行实践练习,研究组在此基础上应用快速评估转盘练习评估技术,应用柯氏4级评估模式(反应、学习、行为和结果)对两组培训效果进行评价。结果研究组对培训形式、效果及总体满意度均高于对照组,出血量的评估效率及液体复苏的掌握率均明显高于对照组,且评估时间缩短至(8.82±2.13)min,两组间差异有统计学意义(t=8.38,P<0.05)。结论研究组学员对于快速评估转盘在出血评估技术工作坊的应用满意度较高,认为能显著提高对出血量的评估效率及液体复苏的掌握率,有一定的临床推广价值。 展开更多
关键词 动态病例情景 快速评估转盘 工作坊 出血评估技术
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基于多软件平台的二维重载精密转台的控制特性仿真分析及优化 被引量:2
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作者 杨东明 胡晓兵 +1 位作者 郭亮 官涛 《四川大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第1期214-222,共9页
为提高二维重载精密转台动态特性,基于AMEsim、ADAMS以及Simulink多软件机电一体化联合仿真对系统控制特性进行仿真分析.本文使用AMESim建立电机模型,Adams建立二维重载系统的动力学模型,使用Simulink工具箱建立PID控制模型,最终建立三... 为提高二维重载精密转台动态特性,基于AMEsim、ADAMS以及Simulink多软件机电一体化联合仿真对系统控制特性进行仿真分析.本文使用AMESim建立电机模型,Adams建立二维重载系统的动力学模型,使用Simulink工具箱建立PID控制模型,最终建立三软件联合仿真模型对系统阶跃响应进行仿真分析;针对系统存在时变性、非线性和负载干扰等因素的问题,采用自适应模糊PID控制算法对系统进行控制优化.仿真结果表明,模糊PID控制算法有着响应快、无超调,稳定误差较普通PID控制减小37%左右等优点. 展开更多
关键词 二维重载精密转台 平台联合仿真 控制优化 模糊PID控制
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并联结构轴系回转误差建模及装配优化
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作者 董一鸣 江波 +3 位作者 李翔宇 谢友金 吕涛 阮萍 《中国光学(中英文)》 EI CAS CSCD 北大核心 2024年第3期586-594,共9页
为提高光电经纬仪等二维转台的轴系运动精度,本文基于雅可比旋量理论建立了一种可考虑零件结构误差及其耦合放大效应的数学模型。针对“一端固定、一端游动”的轴系结构,提出了局部并联结构的分析方法。通过数值仿真分析,获得了各零件... 为提高光电经纬仪等二维转台的轴系运动精度,本文基于雅可比旋量理论建立了一种可考虑零件结构误差及其耦合放大效应的数学模型。针对“一端固定、一端游动”的轴系结构,提出了局部并联结构的分析方法。通过数值仿真分析,获得了各零件结构误差对轴系运动精度的影响以及最优的轴系装配方案。光学口径为650 mm的光电经纬仪的装调结果表明:装配优化后的轴系运动精度较优化前提高了32.1%。所构造的轴系运动精度模型及优化方法为指导光电经纬仪等二维转台的轴系装调以及公差设计提供了一定的理论根据。 展开更多
关键词 光学测量 二维转台 轴系运动模型 光电经纬仪 装配优化
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自动化专业实验创新平台设计与教学研究
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作者 霍鑫 岳明潭 +3 位作者 弭宝涵 张华 鲁佳 马杰 《实验室研究与探索》 CAS 北大核心 2024年第6期42-46,共5页
面向新工科背景下培养创新人才的需求,结合目前自动化专业学生培养的现状,参照飞行器地面半实物仿真测试装备,开发并搭建了模拟飞行转台实验创新平台。该实验创新平台由机械结构、驱动系统、控制系统、人机交互界面和通信接口共同组成,... 面向新工科背景下培养创新人才的需求,结合目前自动化专业学生培养的现状,参照飞行器地面半实物仿真测试装备,开发并搭建了模拟飞行转台实验创新平台。该实验创新平台由机械结构、驱动系统、控制系统、人机交互界面和通信接口共同组成,可以实现俯仰、偏航和滚转的三自由度姿态模拟。教学实践结果表明,该平台不仅为学生提供被控对象拟合、PID控制器设计等基础实验,还可根据学生创新需求,使用预留接口自主设计创新实验;同时,具有形象生动、轻便易携带、人机交互简便、接口丰富、功能拓展性强等优势。 展开更多
关键词 实验教学 创新人才培养 模拟飞行转台 实验平台
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卧式加工中心转台回转夹具定位销连线的数学建模及实例应用研究分析 被引量:1
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作者 李生斌 陈帅 +3 位作者 宋伟 王鹏 刘润杰 许小明 《制造技术与机床》 北大核心 2024年第3期120-125,共6页
卧式加工中心转台回转夹具的典型结构是通过在卧式加工中心工作台上配置转台、尾座和夹具体,进而构成摇篮式转台,该种方式可以使加工工序集中化,进一步提高零件的加工质量和加工效率。在基于摇篮式转台回转夹具构成型式分析的基础上,以... 卧式加工中心转台回转夹具的典型结构是通过在卧式加工中心工作台上配置转台、尾座和夹具体,进而构成摇篮式转台,该种方式可以使加工工序集中化,进一步提高零件的加工质量和加工效率。在基于摇篮式转台回转夹具构成型式分析的基础上,以定位销连线为研究对象,通过讨论定位销连线与转台回转轴线及机床坐标系三者之间平行关系的几种情况,进而建立数学模型,并通过实例的方式解决生产过程中遇到的实际问题。 展开更多
关键词 卧式加工中心 转台回转夹具 定位销连线 转台回转轴线 机床坐标系
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