资源类型

期刊论文 22

年份

2023 1

2022 2

2020 2

2018 1

2017 2

2016 2

2015 1

2014 3

2013 1

2012 2

2009 1

2008 1

2007 1

2002 1

2000 1

展开 ︾

关键词

QB50;ZJUCubeSat;大气阻力;编队飞行 1

五相感应电机;电子变极;滑模控制;指数响应;转矩脉动减小 1

减阻 1

力矩波动 1

化学添加剂 1

叶片风速仪 1

外骨骼;物理人机交互;力矩传感器;人体步态;卡尔曼平滑器 1

大惯量 1

感应电机 1

振型与频率 1

推力与阻力 1

无速度传感器 1

柴油机 1

横向振动 1

死区 1

永磁同步发电机;径向通风孔;转矩脉动;分段斜极;磁体形状优化;有限元分析;风电 1

涡流 1

涡流动量计 1

火箭 1

展开 ︾

检索范围:

排序: 展示方式:

Development of an analytical model to estimate the churning losses in high-speed axial piston pumps

《机械工程前沿(英文)》 2022年 第17卷 第2期 doi: 10.1007/s11465-021-0671-1

摘要: The axial piston pumps in aerospace applications are often characterized by high-speed rotation to achieve great power density. However, their internal rotating parts are fully immersed in the casing oil during operation, leading to considerable churning losses (more than 10% of total power losses) at high rotational speeds. The churning losses deserve much attention at the design stage of high-speed axial piston pumps, but accurate analytical models are not available to estimate the drag torque associated with the churning losses. In this paper, we derive the analytical expressions of the drag torque acting on the key rotating parts immersed in oil, including the cylinder block and the multiple pistons in a circular array. The calculated drag torque agrees well with the experimental data over a wide range of rotational speeds from 1500 to 12000 r/min. The presented analytical model provides practical guidelines for reducing the churning losses in high-speed axial piston pumps or motors.

关键词: axial piston pump     rotating parts     high rotational speed     churning losses     drag torque    

Effect of adjusted mesoscale drag model on flue gas desulfurization in powder-particle spouted beds

《化学科学与工程前沿(英文)》 2022年 第16卷 第6期   页码 909-920 doi: 10.1007/s11705-021-2100-8

摘要: An energy minimum multiscale model was adjusted to simulate the mesoscale structure of the flue gas desulfurization process in a powder-particle spouted bed and verified experimentally. The obtained results revealed that the spout morphology simulated by the adjusted mesoscale drag model was unstable and discontinuous bubbling spout unlike the stable continuous spout obtained using the Gidaspow model. In addition, more thorough gas radial mixing was achieved using the adjusted mesoscale drag model. The mass fraction of water in the gas mixture at the outlet determined by the heterogeneous drag model was 1.5 times higher than that obtained by the homogeneous drag model during the simulation of water vaporization. For the desulfurization reaction, the experimental desulfurization efficiency was 75.03%, while the desulfurization efficiencies obtained by the Gidaspow and adjusted mesoscale drag models were 47.63% and 75.08%, respectively, indicating much higher accuracy of the latter technique.

关键词: adjusted mesoscale drag model     particle image velocimetry     water vaporization     desulfurization reaction     numerical simulation    

New nonlinear stiffness actuator with predefined torque‒deflection profile

《机械工程前沿(英文)》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0721-3

摘要: A nonlinear stiffness actuator (NSA) could achieve high torque/force resolution in low stiffness range and high bandwidth in high stiffness range, both of which are beneficial for physical interaction between a robot and the environment. Currently, most of NSAs are complex and hardly used for engineering. In this paper, oriented to engineering applications, a new simple NSA was proposed, mainly including leaf springs and especially designed cams, which could perform a predefined relationship between torque and deflection. The new NSA has a compact structure, and it is lightweight, both of which are also beneficial for its practical application. An analytical methodology that maps the predefined relationship between torque and deflection to the profile of the cam was developed. The optimal parameters of the structure were given by analyzing the weight of the NSA and the mechanic characteristic of the leaf spring. Though sliding friction force is inevitable because no rollers were used in the cam-based mechanism, the sliding displacement between the cam and the leaf spring is very small, and consumption of sliding friction force is very low. Simulations of different torque‒deflection profiles were carried out to verify the accuracy and applicability of performing predefined torque‒deflection profiles. Three kinds of prototype experiments, including verification experiment of the predefined torque‒deflection profile, torque tracking experiment, and position tracking experiment under different loads, were conducted. The results prove the accuracy of performing the predefined torque‒deflection profile, the tracking performance, and the interactive performance of the new NSA.

关键词: compliant actuator     nonlinear stiffness actuator     nonlinear spring     predefined torque−deflection profile    

Analysis and characterization of wind-solar-constant torque spring hybridized model

Shantanu ACHARYA,Subhadeep BHATTACHARJEE

《能源前沿(英文)》 2014年 第8卷 第3期   页码 279-289 doi: 10.1007/s11708-014-0312-z

摘要: Solar and wind are the most promising renewable energy resources. But their unpredictable and varying nature prevents them from being used as the sole resource for power generation. This paper presents a model of wind and solar thermal hybrid power plant with a spring storage system which is expected to play an efficient role in combating with the drawbacks related to renewable power generation. In the proposed scheme, wind energy is harnessed by a hybrid vertical axis wind turbine, solar energy is utilized by a Stirling engine, and the surplus energy is stored in a winding spring. The paper discusses the working methodologies and analyses the performance of such 2.6 kW hybrid power plant model. It has been observed that the plant is capable of consistently generating 50% of its rated capacity irrespective of limitations in solar and wind resources.

关键词: hybrid vertical axis wind turbine     Stirling engine     solar-thermal energy     wind energy     constant torque spring    

在推力和阻力作用下飞行器横向振动分析

宋健

《中国工程科学》 2000年 第2卷 第10期   页码 63-72

摘要:

文章重点讨论了推力和空气阻力对火箭横向振动频率和振型的影响,分析了在推力和阻力作用下频率降低的原因,给出了推力对振型频率影响的估计式。发动机喷管与火箭固联时的横向运动方程式及其相应的边界条件是分析工作的基础。文中得到的主要结论适用于主动加速段、被动减速段和推力与阻力平衡时的巡航段。在小推力和小轴向过载的情况下,各种不同的计算方法所得的结果相差不大。在大推力和高过载情况下,不同的近似解与精确解的差别可能是很大的。

关键词: 飞行器     火箭     横向振动     推力与阻力     振型与频率    

Comparative study of various artificial intelligence approaches applied to direct torque control of induction

Moulay Rachid DOUIRI, Mohamed CHERKAOUI

《能源前沿(英文)》 2013年 第7卷 第4期   页码 456-467 doi: 10.1007/s11708-013-0264-8

摘要: In this paper, three intelligent approaches were proposed, applied to direct torque control (DTC) of induction motor drive to replace conventional hysteresis comparators and selection table, namely fuzzy logic, artificial neural network and adaptive neuro-fuzzy inference system (ANFIS). The simulated results obtained demonstrate the feasibility of the adaptive network-based fuzzy inference system based direct torque control (ANFIS-DTC). Compared with the classical direct torque control, fuzzy logic based direct torque control (FL-DTC), and neural networks based direct torque control (NN-DTC), the proposed ANFIS-based scheme optimizes the electromagnetic torque and stator flux ripples, and incurs much shorter execution times and hence the errors caused by control time delays are minimized. The validity of the proposed methods is confirmed by simulation results.

关键词: adaptive neuro-fuzzy inference system (ANFIS)     artificial neural network     direct torque control (DTC)     fuzzy logic     induction motor    

Analytical model and finite element computation of braking torque in electromagnetic retarder

Lezhi YE,Guangzhao YANG,Desheng LI

《机械工程前沿(英文)》 2014年 第9卷 第4期   页码 368-379 doi: 10.1007/s11465-014-0314-x

摘要:

An analytical model has been developed for analyzing the braking torque in electromagnetic retarder by flux tube and armature reaction method. The magnetic field distribution in air gap, the eddy current induced in the rotor and the braking torque are calculated by the developed model. Two-dimensional and three-dimensional finite element models for retarder have also been developed. Results from the analytical model are compared with those from finite element models. The validity of these three models is checked by the comparison of the theoretical predictions and the measurements from an experimental prototype. The influencing factors of braking torque have been studied.

关键词: electromagnetic retarder     magnetic field distribution     magnetic circuit     finite element method    

基于大气阻力的立方星编队飞行非线性规划控制算法 Article

Sheng-chao DENG, Tao MENG, Zhong-he JIN

《信息与电子工程前沿(英文)》 2017年 第18卷 第7期   页码 867-881 doi: 10.1631/FITEE.1500493

摘要: 立方星由于体积和功率限制,难以配置传统的推进系统以实现编队飞行。而大气阻力是低轨卫星可以用于轨道调整的空间环境动力之一。本文提出一种通过大气阻力实现轨道面内沿迹跟飞编队的综合策略,并将用于浙江大学下一颗皮纳卫星(该卫星是国际QB50项目成员之一)。QB50项目主要任务是90–300 km高度近地大气层探测。在这一轨道高度,大气阻力对卫星姿态和轨道的影响均不能忽略。本文通过空气动力学分析,同时考虑大气阻力对轨道半长轴和偏心率的影响,设计了一种多维非线性约束规划策略,以计算实现编队所需的卫星之间不同的目标面质比和相应的轨道调整保持时间。此外,通过俯仰姿态机动调整目标面质比。该算法策略无需卫星配置任何展开机构。基于ZJUCubeSat的数值仿真验证了这一设计的可行性和优势。

关键词: QB50;ZJUCubeSat;大气阻力;编队飞行    

Robust SVM-direct torque control of induction motor based on sliding mode controller and sliding mode

Abdelkarim AMMAR,Amor BOUREK,Abdelhamid BENAKCHA

《能源前沿(英文)》 2020年 第14卷 第4期   页码 836-849 doi: 10.1007/s11708-017-0444-z

摘要: This paper proposes a design of control and estimation strategy for induction motor based on the variable structure approach. It describes a coupling of sliding mode direct torque control (DTC) with sliding mode flux and speed observer. This algorithm uses direct torque control basics and the sliding mode approach. A robust electromagnetic torque and flux controllers are designed to overcome the conventional SVM-DTC drawbacks and to ensure fast response and full reference tracking with desired dynamic behavior and low ripple level. The sliding mode controller is used to generate reference voltages in stationary frame and give them to the controlled motor after modulation by a space vector modulation (SVM) inverter. The second aim of this paper is to design a sliding mode speed/flux observer which can improve the control performances by using a sensorless algorithm to get an accurate estimation, and consequently, increase the reliability of the system and decrease the cost of using sensors. The effectiveness of the whole composed control algorithm is investigated in different robustness tests with simulation using Matlab/Simulink and verified by real time experimental implementation based on dS pace 1104 board.

关键词: induction motor     direct torque control (DTC)     space vector modulation (SVM)     sliding mode control (SMC)     sliding mode observer (SMO)     dS1104    

A total torque index for dynamic performance evaluation of a radial symmetric six-legged robot

Kejia LI, Xilun DING, Marco CECCARELL

《机械工程前沿(英文)》 2012年 第7卷 第2期   页码 219-230 doi: 10.1007/s11465-012-0320-9

摘要:

This article focuses on the dynamic index and performance of a radial symmetric six-legged robot. At first the structure of the robot is described in brief and its inverse kinematics is presented. Then the dynamic model is formulated as based on the Lagrange equations. A novel index of total torque is proposed by considering the posture of the supporting legs. The new index can be used to optimize the leg’s structure and operation for consuming minimum power and avoiding unstable postures of the robot. A characterization of the proposed six-legged robot is obtained by a parametric analysis of robot performance through simulation using the presented dynamic model. Main influences are outlined as well as the usefulness of the proposed performance index.

关键词: six-legged robots     dynamic modeling     performance index    

Sensorless direct torque control for salient-pole PMSM based on extended Kalman filter fed by AC/DC/AC

F. BENCHABANE, A. TITAOUINE, O. BENNIS, K. YAHIA, D. TAIBI, A. GUETTAF

《能源前沿(英文)》 2012年 第6卷 第3期   页码 247-254 doi: 10.1007/s11708-012-0190-1

摘要: In this paper, a new sensorless interior permanent magnet synchronous motor (IPMSM) drives method with extended Kalman filter (EKF) for speed, rotor position and load torque estimation is proposed. The direct torque control (DTC) technique for permanent magnet synchronous motor (PMSM) is receiving increasing attention due to the important advantages of the low dependence on motor parameters when compared with other motor control techniques. The Kalman filter is an observer for linear and non-linear systems and is based on the stochastic intromission, in others words, noise. The PMSM is fed by an indirect power electronic converter which is controlled by a sliding mode technique. The simulation tests performed for different operating conditions have confirmed the robustness of the overall system; and it is shown that the sliding mode technique has successfully minimized the different harmonics introduced by the line converter.

关键词: direct torque control (DTC)     sensorless control     extended Kalman filter (EKF)     permanent magnet synchronous motor (PMSM)     boost-rectifier    

Method of internal 3D flow field numerical simulation for hydrodynamic torque converter

SHANG Tao, ZHAO Dingxuan, ZHANG Yuankun, GUO Xiangen, SHI Xiangzhong

《机械工程前沿(英文)》 2008年 第3卷 第1期   页码 86-90 doi: 10.1007/s11465-008-0012-7

摘要: To enhance the performance of a hydrodynamic torque converter and thoroughly understand the trait of inside flow, a numerical simulation method of internal 3D flow for the three-element centrifugal hydrodynamic torque converter was systematically researched and expatiated in this paper. First, the internal flow field of each impeller was calculated. The curves that illustrate the relationships between the pressure differences of the inlet and outlet versus flux were drawn. Second, the concurrent working point of each impeller was approximately estimated. Finally, a calculation was performed considering the influence on each impeller. The flow field of a working point was solved by multiple calculations and the actual working condition was gradually determined. The pressure and velocity distributions of the flow field were proposed. The performance parameters of the hydrodynamic torque converter were predicted. The calculation method, and the proposed pressure and velocity distribution of the flow field, have practical significance for the design and improvement of a hydrodynamic torque converter.

关键词: velocity distribution     calculation     numerical simulation     three-element centrifugal     converter    

Static balancing of planar articulated robots

Giuseppe QUAGLIA,Zhe YIN

《机械工程前沿(英文)》 2015年 第10卷 第4期   页码 326-343 doi: 10.1007/s11465-015-0355-9

摘要:

Static balancing for a manipulator’s weight is necessary in terms of energy saving and performance improvement. This paper proposes a method to design balancing devices for articulated robots in industry, based on robotic dynamics. Full design details for the balancing system using springs are presented from two aspects: One is the optimization for the position of the balancing system; the other is the design of the spring parameters. As examples, two feasible balancing devices are proposed, based on different robotic structures: The first solution consists of linkages and springs; the other consists of pulleys, cross mechanisms and (hydro-) pneumatic springs. Then the two solutions are compared. Pneumatic, hydro-pneumatic and mechanical springs are discussed and their parameters are decided according to the requirements of torque compensation. Numerical results show that with the proper design using the methodology presented in this paper, an articulated robot can be statically balanced perfectly in all configurations. This paper therefore provides a design method of the balancing system for other similar structures.

关键词: robotics     static balancing     pneumatic spring     mechanical spring     torque compensation    

海洋二号卫星大惯量旋转部件干扰力矩抑制技术

周勇,李正军,马超,王小宁

《中国工程科学》 2014年 第16卷 第3期   页码 43-49

摘要:

海洋二号(HY-2A)卫星要求微波散射计和微波辐射计实现扫描过程中所产生的力矩波动不能影响卫星姿态稳定度。这两个载荷使用永磁同步电动机矢量控制,对负载直接驱动;通过电机本体采用齿槽转矩优化设计、采用固定角度计时法消除量化误差、相电流测量误差控制、逆变器死区补偿等措施,抑制转矩波动。通过电机本体和控制策略进行联合精确模型仿真,分析了系统的转矩波动。由在轨遥测数据分析可得,实现了大惯量旋转部件的精确控制。

关键词: 大惯量     力矩波动     量化误差     死区     精确模型    

基于无速度传感器直接转矩控制自抗扰交流调速研究

戴巨川, 吴新开,文丽

《中国工程科学》 2009年 第11卷 第4期   页码 91-95

摘要:

在感应电机直接转矩控制(DTC)调速系统中,常规PID速度调节器在电机受到扰动的情况下,需要花费较长时间才能使电机恢复到稳态值。为此,将一种新型的自抗扰控制器(ADRC)引入感应电机直接转矩控制调速系统中,设计速度ADRC调节器代替PID调节器,基于模型参考自适应控制(MRAS)方法设计速度观测器。对比分析了PID与ADRC两种方案下无速度传感器直接转矩控制交流调速系统性能。仿真试验结果表明,采用ADRC后,系统动态响应更快,抗扰动能力更强,在电机参数摄动的情况下,电机运行速度与指令速度偏差更小。

关键词: 直接转矩控制     自抗扰控制     速度观测器     无速度传感器     感应电机    

标题 作者 时间 类型 操作

Development of an analytical model to estimate the churning losses in high-speed axial piston pumps

期刊论文

Effect of adjusted mesoscale drag model on flue gas desulfurization in powder-particle spouted beds

期刊论文

New nonlinear stiffness actuator with predefined torque‒deflection profile

期刊论文

Analysis and characterization of wind-solar-constant torque spring hybridized model

Shantanu ACHARYA,Subhadeep BHATTACHARJEE

期刊论文

在推力和阻力作用下飞行器横向振动分析

宋健

期刊论文

Comparative study of various artificial intelligence approaches applied to direct torque control of induction

Moulay Rachid DOUIRI, Mohamed CHERKAOUI

期刊论文

Analytical model and finite element computation of braking torque in electromagnetic retarder

Lezhi YE,Guangzhao YANG,Desheng LI

期刊论文

基于大气阻力的立方星编队飞行非线性规划控制算法

Sheng-chao DENG, Tao MENG, Zhong-he JIN

期刊论文

Robust SVM-direct torque control of induction motor based on sliding mode controller and sliding mode

Abdelkarim AMMAR,Amor BOUREK,Abdelhamid BENAKCHA

期刊论文

A total torque index for dynamic performance evaluation of a radial symmetric six-legged robot

Kejia LI, Xilun DING, Marco CECCARELL

期刊论文

Sensorless direct torque control for salient-pole PMSM based on extended Kalman filter fed by AC/DC/AC

F. BENCHABANE, A. TITAOUINE, O. BENNIS, K. YAHIA, D. TAIBI, A. GUETTAF

期刊论文

Method of internal 3D flow field numerical simulation for hydrodynamic torque converter

SHANG Tao, ZHAO Dingxuan, ZHANG Yuankun, GUO Xiangen, SHI Xiangzhong

期刊论文

Static balancing of planar articulated robots

Giuseppe QUAGLIA,Zhe YIN

期刊论文

海洋二号卫星大惯量旋转部件干扰力矩抑制技术

周勇,李正军,马超,王小宁

期刊论文

基于无速度传感器直接转矩控制自抗扰交流调速研究

戴巨川, 吴新开,文丽

期刊论文