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基于电磁作动的主动吸振器的力特性 预览
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作者 傅涛 殷智宏 +1 位作者 任艳 上官文斌 《华南理工大学学报:自然科学版》 EI CAS CSCD 北大核心 2020年第1期10-18,共9页
以电磁铁为作动器,提出了一种新型电磁式主动吸振器,并对其力特性进行了研究。首先,建立了作动器的电磁力数学模型;然后,基于作动器的电磁力数学模型,建立了主动吸振器的运动学方程,并对其电磁力和驱动力特性进行了分析;最后,考虑到主... 以电磁铁为作动器,提出了一种新型电磁式主动吸振器,并对其力特性进行了研究。首先,建立了作动器的电磁力数学模型;然后,基于作动器的电磁力数学模型,建立了主动吸振器的运动学方程,并对其电磁力和驱动力特性进行了分析;最后,考虑到主动吸振器在实际工作中产生的驱动力与理想驱动力之间存在不可避免的偏差,对实际驱动力与理想驱动力存在一定的幅值、相位和频率差时对主动吸振器减振效果的影响进行了理论分析,并搭建了简支平板试验台,对理论分析结果进行了试验验证。结果表明:实际驱动力与理想驱动力的幅值、相位差越大,减振效果越差;当实际驱动力与理想驱动力存在频率差时,主动吸振器无减振效果。 展开更多
关键词 作动器 主动吸振器 电磁铁 电磁力 驱动力 减振
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A Delay-Dependent Anti-Windup Compensator for Wide-Area Power Systems With Time-Varying Delays and Actuator Saturation 预览
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作者 Maddela Chinna Obaiah Bidyadhar Subudhi 《自动化学报:英文版》 CSCD 2020年第1期106-117,共12页
In this paper, a delay-dependent anti-windup compensator is designed for wide-area power systems to enhance the damping of inter-area low-frequency oscillations in the presence of time-varying delays and actuator satu... In this paper, a delay-dependent anti-windup compensator is designed for wide-area power systems to enhance the damping of inter-area low-frequency oscillations in the presence of time-varying delays and actuator saturation using an indirect approach. In this approach, first, a conventional wide-area damping controller is designed by using output feedback with regional pole placement approach without considering time-varying delays and actuator saturation. Then to mitigate the effect of both time-varying delays and actuator saturation, an add-on delay-dependent anti-windup compensator is designed. Based on generalized sector conditions, less conservative delay-dependent sufficient conditions are derived in the form of a linear matrix inequality(LMI) to guarantee the asymptotic stability of the closedloop system in the presence of time-varying delays and actuator saturation by using Lyapunov-Krasovskii functional and Jensen integral inequality. Based on sufficient conditions, the LMI-based optimization problem is formulated and solved to obtain the compensator gain which maximizes the estimation of the region of attraction and minimizes the upper bound of-gain. Nonlinear simulations are performed first using MATLAB/Simulink on a two-area four-machine power system to evaluate the performance of the proposed controller for two operating conditions, e.g.,3-phase to ground fault and generator 1 terminal voltage variation. Then the proposed controller is implemented in real-time on an OPAL-RT digital simulator. From the results obtained it is verified that the proposed controller provides sufficient damping to the inter-area oscillations in the presence of time-varying delays and actuator saturation and maximizes the estimation of the region of attraction. 展开更多
关键词 Index Terms—Anti-windup compensator actuator saturation FACTS devices H∞controller inter-area oscillations LMI time delay.
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燃气作动筒驱动弹翼展开实验与仿真 预览
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作者 吴俊全 王蓉晖 孙海文 《兵工自动化》 2020年第1期60-62,73,共4页
针对目前关于燃气作动筒式折叠翼技术大多数采用的是动力学性能仿真、机构的原理分析等现象,通过地面试验与ADAMS动力学仿真计算分别对某燃气作动筒驱动折叠翼的展开过程进行分析,并将地面试验数据与仿真计算结果进行比较和分析。结果表... 针对目前关于燃气作动筒式折叠翼技术大多数采用的是动力学性能仿真、机构的原理分析等现象,通过地面试验与ADAMS动力学仿真计算分别对某燃气作动筒驱动折叠翼的展开过程进行分析,并将地面试验数据与仿真计算结果进行比较和分析。结果表明:燃气作动筒装药结构形式、燃速控制合理,折叠翼机构满足使用要求。 展开更多
关键词 折叠翼 作动筒 仿真 试验
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某300 MW机组水轮机调节系统参数实测及建模分析 预览
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作者 冯雁敏 张雪源 +1 位作者 李明 黄琢 《长江科学院院报》 CSCD 北大核心 2020年第1期172-178,共7页
为提高电力系统稳定分析计算的准确性和电网调度对试验机组生产调度的科学性,对某300 MW混流式水电机组进行水轮机调节系统控制参数测试和建模分析。以试验机组水力机械特性和调速系统实际控制逻辑为依据,兼顾调节控制的死区、限幅、延... 为提高电力系统稳定分析计算的准确性和电网调度对试验机组生产调度的科学性,对某300 MW混流式水电机组进行水轮机调节系统控制参数测试和建模分析。以试验机组水力机械特性和调速系统实际控制逻辑为依据,兼顾调节控制的死区、限幅、延时、非线性函数等因素导致的非线性特性和仿真计算的方便简约性,在MatLab/Simulink中对水轮机调节系统的电气控制、液压系统和原动机3个环节进行建模;针对原动机环节分别建立了电力系统分析综合程序通用模型和自定义模型;对模型参数进行了现场实测和仿真辨识,并对电力系统分析综合程序通用模型和自定义模型进行比较分析。结果表明自定义模型参数能更好地反映机组设备本身的动态响应特性。该模型的建立为水电机组电力稳定计算分析领域的完善和发展提供了参考。 展开更多
关键词 水轮机调节系统 执行机构 参数实测 建模 非线性 电力系统稳定计算
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基于机器视觉的草莓自动采摘机的设计 预览 被引量:1
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作者 陈军 张继耀 张欣 《农机化研究》 北大核心 2020年第2期141-145,共5页
针对我国大面积高垄种植草莓存在的采摘效率低、损伤率高等问题,设计开发了一种基于机器视觉的草莓自动采摘机。该机基于机器视觉识别成熟草莓位置和精准定位,采用步进电机带动同步带运动,让末端执行器执行采摘动作的机构,可一次完成采... 针对我国大面积高垄种植草莓存在的采摘效率低、损伤率高等问题,设计开发了一种基于机器视觉的草莓自动采摘机。该机基于机器视觉识别成熟草莓位置和精准定位,采用步进电机带动同步带运动,让末端执行器执行采摘动作的机构,可一次完成采摘、传送及收集等作业。该采摘机主要由采摘系统、传输系统和收集系统组成。试验结果表明:该机在试验环境下对草莓的采摘速度为403.4颗/h,无损伤采摘成功率可达90%。 展开更多
关键词 草莓自动采摘机 机器视觉 末端执行器 无损伤采摘
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A Localized Inter-Actuator Network Topology Repair Scheme for Wireless Sensor and Actuator Networks 预览
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作者 Yong Feng Hai Liu +1 位作者 Jie Yang Xiaodong Fu 《中国通信:英文版》 SCIE CSCD 2019年第2期215-232,共18页
Node failure is one of the most severe problems that wireless sensor and actuator networks(WSANs)have to deal with.The failure of actuator nodes,in particular,may result in substantial consequences such as network par... Node failure is one of the most severe problems that wireless sensor and actuator networks(WSANs)have to deal with.The failure of actuator nodes,in particular,may result in substantial consequences such as network partitioning,incorrect and incomplete decision execution for WSANs.This paper proposes an efficient localized scheme,called LANTR,to repair the damaged topology of inter-actuator network while single actuator node paralyzes.For the failure of an ordinary actuator node,LANTR can rapidly repair the topology through relocating only one-hop neighbors of the failure node,meanwhile,keep the original topology structure as much as possible.Given the magnitude of cut vertex actuators playing on the connectivity,LANTR designs a novel method for each cut vertex to select out a specific guardian node with the minimum degree or minimum cumulative degree from its neighbors,which can reduce the repair influence on the original topology and effectively reduce the coverage loss rate.The performance of the proposed scheme is evaluated and compared with several existing representative topology repair schemes,and the results indicate that LANTR can more effectively and efficiently repair the topology of inter-actuator networks. 展开更多
关键词 wireless sensor and ACTUATOR NETWORKS inter-actuator NETWORKS topology REPAIR COVERAGE loss rate
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Enhanced Ferroelectric and Converse Piezoelectric Properties of Dense Lead-Free Na<sub>0.4</sub>K<sub>0.1</sub>Bi<sub>0.5</sub>TiO<sub>3</sub>Ceramics for Actuator Applications 预览
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作者 N. Shara Sowmya Pravin Varade +1 位作者 Narayanan Venkataramani Ajit R. Kulkarni 《材料物理与化学进展(英文)》 2019年第1期1-10,共10页
In this work, lead-free Na0.4Bi0.5 TiO3-K0.1Bi0.5TiO3 (NKBT) piezoelectric ceramics were prepared by the solid-state reaction method and their structural, ferroelectric and dielectric properties were systematically st... In this work, lead-free Na0.4Bi0.5 TiO3-K0.1Bi0.5TiO3 (NKBT) piezoelectric ceramics were prepared by the solid-state reaction method and their structural, ferroelectric and dielectric properties were systematically studied. NKBT sintered at 1150℃ for 4 h exhibited highly dense (96% - 98% of the theoretical density) and uniform grains of size 1.1 μm. The coexistence of tetragonal (P4bm) and rhombohedral (R3c) phases due to the presence of morphotrophic phase boundary for the chosen composition has been confirmed by the Rietveld refinement studies. Enhanced ferroelectric properties such as remnant polarization (Pr) and coercive field (EC) are found to be 37 μC/cm2 and 30 kV/cm, respectively. The optimized synthesis procedure for NKBT ceramics resulted in enhanced strain (%) and converse piezoelectric coefficient (d33*) of 0.3 % and 554 pm/V which is attributed to smaller grain size and switching of non 180o domains. NKBT ceramics with such excellent piezoelectric properties can be considered as a promising candidate for actuator applications. 展开更多
关键词 LEAD-FREE PIEZOELECTRIC Morphotropic Phase Boundary CONVERSE PIEZOELECTRIC Coefficient ACTUATOR
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机载红外搜索跟踪系统仿真测试平台设计 预览
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作者 李洁 孙科峰 《电光与控制》 CSCD 北大核心 2019年第8期101-105,110共6页
针对机载IRST系统具有大视场、高空间分辨率、高扫描速度的3项技术指标特点,设计了一种单元化结构的新型IRST仿真测试平台,解决了传统仿真系统无法同时满足该3项技术指标要求的难题。仿真测试平台由仿真中心、激励器、仿真器和显控终端... 针对机载IRST系统具有大视场、高空间分辨率、高扫描速度的3项技术指标特点,设计了一种单元化结构的新型IRST仿真测试平台,解决了传统仿真系统无法同时满足该3项技术指标要求的难题。仿真测试平台由仿真中心、激励器、仿真器和显控终端共4个单元构成,具有5种工作方式。激励器采用基于时间序列的面阵场景发生方法,将大视场、高分辨率的仿真场景分割成序列化小视场、标准分辨率的面阵场景;采用光纤网络将面阵场景的视频信号和时序信息同时发送到仿真器,仿真器根据工作方式采用不同的处理方法对视频信号进行处理。测试结果表明,仿真测试平台能够仿真真实机载IRST系统的综合性能、工作方式和接口方式,现已经应用于航电任务软件的联试和航电系统的性能测试。 展开更多
关键词 红外搜索跟踪 仿真测试平台 激励器 仿真器 信息交联 测试验证
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SVD Approach for Actuator and Sensor Placement in Active Vibration Control of Large Cable Net Structures 预览
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作者 Yang Liu Weizhong Zhang Xiuyun Meng 《北京理工大学学报:英文版》 EI CAS 2019年第4期675-686,共12页
The actuator and sensor placement problem for active vibration control of large cable net structures is investigated in this paper.Since the structures exhibit closely spaced modes in the range of low frequencies,the ... The actuator and sensor placement problem for active vibration control of large cable net structures is investigated in this paper.Since the structures exhibit closely spaced modes in the range of low frequencies,the number of modes to be considered is quite large after modal truncation,while only a limited number of actuators and sensors are to be placed.This makes it hard to determine the actuator and sensor locations with the existing placement methods in the literature such as the methods based on the controllability/observability grammian.To deal with this issue,an actuator and sensor placement method based on singular value decompositions(SVD)of the input and output matrices is proposed,which guarantees the modal controllability and observability of the system.The effectiveness of the SVD based method is verified through numerical simulations in which comparisons are conducted between randomly-chosen locations and the optimal ones obtained by a genetic algorithm. 展开更多
关键词 actuator and sensor placement large cable net structures active vibration control
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主被动一体化隔振装置设计研究 预览
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作者 石慧 闫政涛 +1 位作者 李赫 叶曦 《船舶》 2019年第1期128-135,共8页
针对舰艇舱室设备存在的多激励、低频谱振动问题,开展振动主动控制主被动一体化隔振装置研究,为构建基于浮筏隔振设计的主动控制系统奠定了理论和工程基础。首先,基于电磁作动原理初步设计电磁作动器,通过对动子和定子形态及间隙、线圈... 针对舰艇舱室设备存在的多激励、低频谱振动问题,开展振动主动控制主被动一体化隔振装置研究,为构建基于浮筏隔振设计的主动控制系统奠定了理论和工程基础。首先,基于电磁作动原理初步设计电磁作动器,通过对动子和定子形态及间隙、线圈匝数、倒角形式及大小等进行仿真分析与优化设计;其次,基于COMSOL建模进行电磁特性、发热特性仿真分析;最后,基于浮筏隔振装置隔振、承载及安装需求,设计研制了主被动一体化的隔振装置。试验结果表明:该装置满足次级力源出力特性要求. 展开更多
关键词 振动主动控制 执行作动机构 浮筏隔振 主动隔振
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某卡环内锁作动筒啸叫故障分析 预览
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作者 邹衍 黄志军 +1 位作者 赵振贵 傅琳辉 《教练机》 2019年第3期52-56,共5页
某卡环内锁作动筒活塞部件运动时出现啸叫现象,通过作动筒尺寸链分析,验证了初步确定的故障原因的正确性,并提出了更有效的间隙检测方法。
关键词 作动筒 卡环内锁 啸叫 尺寸链 间隙
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High precision attitude dynamic tracking control of a moving space target
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作者 Yunhua WU Mohong ZHENG +3 位作者 Wei HE Feng WANG Zhiming CHEN Bing HUA 《中国航空学报:英文版》 SCIE EI CAS CSCD 2019年第10期2324-2336,共13页
On-orbit spacecraft face many threats,such as collisions with debris or other spacecraft.Therefore,perception of the surrounding space environment is vitally important for on-orbit spacecraft.Spacecraft require a dyna... On-orbit spacecraft face many threats,such as collisions with debris or other spacecraft.Therefore,perception of the surrounding space environment is vitally important for on-orbit spacecraft.Spacecraft require a dynamic attitude tracking ability with high precision for such missions.This paper aims to address the above problem using an improved backstepping controller.The tracking mission is divided into two phases:coarse alignment and fine alignment.In the first phase,a traditional saturation controller is utilized to limit the maximum attitude angular velocity according to the actuator’s ability.For the second phase,the proposed backstepping controller with different virtual control inputs is applied to track the moving target.To fulfill the high precision attitude tracking requirements,a hybrid attitude control actuator consisting of a Control Moment Gyro(CMG)and Reaction Wheel(RW)is constructed,which can simultaneously avoid the CMG singularity and RW saturation through the use of an angular momentum optimal management strategy,such as null motion.Finally,five simulation scenarios were carried out to demonstrate the effectiveness of the proposed control strategy and hybrid actuator. 展开更多
关键词 Space moving target Attitude dynamic tracking Backstepping controller Improved virtual control input Hybrid actuator
Large nonlinear deflection behavior of IPMC actuators analyzed with an electromechanical model 预览
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作者 H.G.Liu K.Bian K.Xiong 《力学学报:英文版》 SCIE EI CAS CSCD 2019年第5期992-1000,共9页
This study presents an electromechanical engineering model for the analysis of the large deflection curves of ionic polymer-metal composite(IPMC)cantilever actuators under direct current(DC)voltages.In this paper,the ... This study presents an electromechanical engineering model for the analysis of the large deflection curves of ionic polymer-metal composite(IPMC)cantilever actuators under direct current(DC)voltages.In this paper,the longitudinal normal strain performance of the material was investigated using digital image correlation on a micro-scale.The deflection of the actuator is analytically obtained with the application of an elliptic integration method based on the relationship between strain gradient and excitation voltage,and the minimum excitation voltage is derived based on the assumption that the actuators have small deformations.The validity of the electromechanical model is then justified with the experimental results obtained from Pt-and Ag-IPMC actuators at various excitation voltages.The findings of this study confirm that the introduced electromechanical model can accurately describe the large nonlinear deflection behavior of IPMC actuators. 展开更多
关键词 ACTUATOR Ionic polymer metal composite Large deflection Electromechanical model
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Adaptive fault-tolerant control based on boundary estimation for space robot under joint actuator faults and uncertain parameters 预览
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作者 Rong-Hua Lei Li Chen 《Defence Technology(防务技术)》 CAS CSCD 2019年第6期964-971,共8页
Since the joint actuator of the space robot executes the control instructions frequently in the harsh space environment,it is prone to the partial loss of control effectiveness(PLCE)fault.An adaptive fault-tolerant co... Since the joint actuator of the space robot executes the control instructions frequently in the harsh space environment,it is prone to the partial loss of control effectiveness(PLCE)fault.An adaptive fault-tolerant control algorithm is designed for a space robot system with the uncertain parameters and the PLCE actuator faults.The mathematical model of the system is established based on the Lagrange method,and the PLCE actuator fault is described as an effectiveness factor.The lower bound of the effectiveness factors and the upper bound of the uncertain parameters are estimated by an adaptive strategy,and the estimated value is fed back to the control algorithm.Compared with the traditional fault-tolerant algorithms,the proposed algorithm does not need to predetermine the lower bound of the effectiveness factor,hence it is more in line with the actual engineering application.It is proved that the algorithm can guarantee the stability of the closed-loop system based on the Lyapunov function method.The numerical simulation results show that the proposed algorithm can not only compensate for the uncertain parameters,but also can tolerate the PLCE actuator faults effectively,which verifies the effectiveness and superiority of the control scheme. 展开更多
关键词 Space robot Actuator faults Uncertain parameters Effectiveness factor Fault-tolerant control
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新型形状记忆合金驱动器与三指灵巧手设计 预览
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作者 李达宏 金樱子 +1 位作者 郭振武 王斌锐 《工程设计学报》 CSCD 北大核心 2019年第5期506-512,共7页
针对现有形状记忆合金(shape memory alloy,SMA)温度反馈控制难以实现及SMA应变量小导致实际应用中存在驱动位移小的问题,提出了一种基于电阻反馈控制的新型SMA驱动器,并采用这种驱动器研发了一种绳索传动的三指灵巧手。新型SMA驱动器... 针对现有形状记忆合金(shape memory alloy,SMA)温度反馈控制难以实现及SMA应变量小导致实际应用中存在驱动位移小的问题,提出了一种基于电阻反馈控制的新型SMA驱动器,并采用这种驱动器研发了一种绳索传动的三指灵巧手。新型SMA驱动器由滑轮、空心螺柱、SMA丝和弹簧拉伸装置等组成,通过采用滑轮绕线的方式增长SMA丝的使用长度以提高驱动位移输出量;利用SMA自身的电阻特性得到SMA电阻变化与相变的关系,设计了基于电阻反馈的开关控制系统;采用模块化思想设计了三指灵巧手,3根手指共有8个自由度,并通过实验验证三指灵巧手对物品的抓取能力。结果表明:新型SMA驱动器不需要通过测温来判断SMA丝相变进程,省去了外部温度传感器;SMA驱动器输出的驱动量可达驱动器总长的8%以上;通过监测SMA丝的电阻变化可实现驱动器通电加热的控制,防止SMA丝过热烧毁。研究结果为提高SMA驱动器驱动位移和降低SMA驱动器控制难度提供了一种思路。 展开更多
关键词 形状记忆合金 驱动器 电阻效应 灵巧手
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磁致伸缩层合悬臂梁式作动器的振动分析
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作者 徐燕 尚新春 《复合材料学报》 EI CAS CSCD 北大核心 2019年第5期1319-1326,共8页
为了分析磁致伸缩薄膜型层合悬臂梁式作动器的振动问题,应用磁致伸缩材料的非线性本构关系,由哈密尔顿原理导出了双层悬臂梁的振动微分方程。采用分离变量方法和常微分方程组的解析解法对磁致伸缩薄膜型层合悬臂梁的自由振动和受迫振动... 为了分析磁致伸缩薄膜型层合悬臂梁式作动器的振动问题,应用磁致伸缩材料的非线性本构关系,由哈密尔顿原理导出了双层悬臂梁的振动微分方程。采用分离变量方法和常微分方程组的解析解法对磁致伸缩薄膜型层合悬臂梁的自由振动和受迫振动进行了理论分析。数值算例表明本文计算结果与有限元结果吻合较好,从而佐证了本文理论模型和求解方法的正确性,并讨论了几何参数、材料参数对层合梁固有频率的影响。还分析了在周期输入磁场激励下悬臂梁的挠度响应,且挠度响应呈现出倍频效应的动态特性。 展开更多
关键词 作动器 磁致伸缩 层合梁振动 解析解 倍频效应
关节式上下料机器人设计 预览
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作者 宗成国 毛天旭 徐丕兵 《工业控制计算机》 2019年第3期98-99,共2页
通过对机器人未知的工作环境以及不确定性因素的研究与分析,设计了一种基于关节式机器人的六自由度运动方案。首先采用整体结构设计的方法针对关节式机器人在运行过程中的执行机构进行分析,通过对作业内容进行规划,再结合实际需求,完成... 通过对机器人未知的工作环境以及不确定性因素的研究与分析,设计了一种基于关节式机器人的六自由度运动方案。首先采用整体结构设计的方法针对关节式机器人在运行过程中的执行机构进行分析,通过对作业内容进行规划,再结合实际需求,完成对机器人的基本设计;其次,通过建立关节式机器人运动的雅可比矩阵,设计了一个具有自主执行能力的机器人;最后,通过对机器人进行速度分析与验证,基本实现了其执行与运动能力。 展开更多
关键词 关节式机器人 执行机构 雅可比矩阵 速度分析
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浮式风机气动-水动耦合特性数值模拟 预览
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作者 黄扬 程萍 万德成 《船舶与海洋工程学报:英文版》 CSCD 2019年第1期82-92,共11页
The exploration for renewable and clean energies has become crucial due to environmental issues such as global warming and the energy crisis. In recent years,floating offshore wind turbines(FOWTs) have attracted a con... The exploration for renewable and clean energies has become crucial due to environmental issues such as global warming and the energy crisis. In recent years,floating offshore wind turbines(FOWTs) have attracted a considerable amount of attention as a means to exploit steady and strong wind sources available in deep-sea areas. In this study, the coupled aero-hydrodynamic characteristics of a spar-type 5-MW wind turbine are analyzed. An unsteady actuator line model(UALM) coupled with a twophase computational fluid dynamics solver naoe-FOAM-SJTU is applied to solve three-dimensional Reynolds-averaged NavierStokes equations. Simulations with different complexities are performed. First, the wind turbine is parked. Second, the impact of the wind turbine is simplified into equivalent forces and moments. Third, fully coupled dynamic analysis with wind and wave excitation is conducted by utilizing the UALM. From the simulation, aerodynamic forces, including the unsteady aerodynamic power and thrust, can be obtained, and hydrodynamic responses such as the six-degrees-of-freedom motions of the floating platform and the mooring tensions are also available. The coupled responses of the FOWT for cases of different complexities are analyzed based on the simulation results. Findings indicate that the coupling effects between the aerodynamics of the wind turbine and the hydrodynamics of the floating platform are obvious. The aerodynamic loads have a significant effect on the dynamic responses of the floating platform, and the aerodynamic performance of the wind turbine has highly unsteady characteristics due to the motions of the floating platform. A spar-type FOWT consisting of NREL-5-MW baseline wind turbine and OC3-Hywind platform system is investigated. The aerodynamic forces can be obtained by the UALM. The 6 DoF motions and mooring tensions are predicted by the naoe-FOAM-SJTU. To research the coupling effects between the aerodynamics of the wind turbine and the hydrodynamics of the floating platform, simulations with diffe 展开更多
关键词 FLOATING OFFSHORE wind turbine UNSTEADY AERODYNAMICS Hydro dynamic responses Coupling effects naoe-FOAM-SJTU SOLVER ACTUATOR line model
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Experimental study of an insert and its influence on churning losses in a high-speed electro-hydrostatic actuator pump of an aircraft
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作者 Junhui ZHANG Ying LI +2 位作者 Bing XU Min PAN Qun CHAO 《中国航空学报:英文版》 SCIE EI CAS CSCD 2019年第8期2028-2036,共9页
The speed of an Electro-Hydrostatic Actuator(EHA) pump can recently reach 20000 r/min, and its churning losses increase obviously with an increasing speed, which results in low efficiency and thus increasing heat in a... The speed of an Electro-Hydrostatic Actuator(EHA) pump can recently reach 20000 r/min, and its churning losses increase obviously with an increasing speed, which results in low efficiency and thus increasing heat in aircraft EHA systems. In order to reduce churning losses at high speeds, more attention should be given to the design of an insert. In this paper, the effect of an insert with different design parameters on churning losses is investigated through Computational Fluid Dynamics(CFD) simulation and experiments by calculating the difference between churning losses torques of the test pump with and without the insert based on a high-speed churning losses test rig.Analytical results show that the gap between the insert and the cylinder is critical for churning losses reduction. It is found that the churning losses of the test pump can be reduced with a decreasing gap between the cylinder block and the insert at high speeds. This is because the insert can decrease the turbulence occurrence at high speeds. The results can be used for flow field analysis and optimization of the high-speed EHA pump and provide a new method for improving efficiency of high-speed EHA pumps. 展开更多
关键词 CHURNING LOSSES Efficiency Electro-hydrostatic ACTUATOR PUMP High speed INSERT
中速大功率柴油机发电机组调速器起动故障原因分析与解决方案 预览
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作者 屈君 焦联国 +1 位作者 张顺利 张技术 《内燃机》 2019年第6期52-55,共4页
海外热电厂的柴油发电机组配置带有促动器的电液调速器,柴油机具备起动盘车联锁功能。柴油机发电机组首次起动运行时,按下机旁控制柜起动按钮后,未能使柴油机运转起动。首先从促动器、调速器、柴油机控制空气管路及各类控制阀等方面进... 海外热电厂的柴油发电机组配置带有促动器的电液调速器,柴油机具备起动盘车联锁功能。柴油机发电机组首次起动运行时,按下机旁控制柜起动按钮后,未能使柴油机运转起动。首先从促动器、调速器、柴油机控制空气管路及各类控制阀等方面进行故障原因分析和排查,并实施方案验证,确定起动故障原因和解决方案,成功解决该型机调速器起动故障,为该机型系列机和其他柴油机调速器的安装提供了宝贵的经验,本案例解决方案也是柴油机的起动故障原因之一。 展开更多
关键词 促动器 调速器 控制空气 机旁起动 柴油机
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