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无偏溯源角;光栅干涉仪;六自由度测量;角度表达方法 1

模型自适应控制;混合磁轴承;非线性区域;快速响应;高稳定性 1

永磁同步电机;离散电流控制器;复矢量 1

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Error analysis and optimization of a 3-degree of freedom translational Parallel Kinematic Machine

null

《机械工程前沿(英文)》 2014年 第9卷 第2期   页码 120-129 doi: 10.1007/s11465-014-0300-3

摘要:

In this paper, error modeling and analysis of a typical 3-degree of freedom translational Parallel Kinematic Machine is presented. This mechanism provides translational motion along the Cartesian X-, Y- and Z- axes. It consists of three limbs each having an arm and forearm with prismatic-revolute-revolute-revolute joints. The moving or tool platform maintains same orientation in the entire workspace due to its joint arrangement. From inverse kinematics, the joint angles for a given position of tool platform necessary for the error modeling and analysis are obtained. Error modeling is done based on the differentiation of the inverse kinematic equations. Variation of pose errors along XY and Z directions for a set of dimensions of the parallel kinematic machine is presented. A non-dimensional performance index, namely, global error transformation index is used to study the influence of dimensions and its corresponding global maximum pose error is reported. An attempt is made to find the optimal dimensions of the Parallel Kinematic Machine using Genetic Algorithms in MATLAB. The methodology presented and the results obtained are useful for predicting the performance capability of the Parallel Kinematic Machine under study.

关键词: translational Parallel Kinematic Machine     error modeling     global error transformation index    

Singularity loci of an orthogonal spherical two-degree-of-freedom parallel mechanism

Jialun YANG, Feng GAO,

《机械工程前沿(英文)》 2009年 第4卷 第4期   页码 379-385 doi: 10.1007/s11465-009-0075-0

摘要: Singularity analysis plays an important role in the design of robots, especially for parallel robots. In this paper, the direct and inverse kinematics of an orthogonal spherical two-degree-of-freedom parallel mechanism is proposed based on the modified Euler angles. All the singular poses of the mechanism are achieved through the direct kinematic analysis. Self-motions, which are different from the general spherical 5 parallel mechanisms, are also discussed. Singularity loci in the joint space and Cartesian space are plotted according to the Jacobin of the mechanism. Result shows that the singularity loci at the joint space are two circles and one line, whereas at the Cartesian space are a circle.

关键词: 2-DOF orthogonal spherical parallel mechanism     singularity loci     self-motions    

On the location of the secondary instantaneous poles in two-degree-of-freedom spherical mechanisms

Soheil ZARKANDI

《机械工程前沿(英文)》 2014年 第9卷 第1期   页码 34-40 doi: 10.1007/s11465-014-0290-1

摘要:

As the instant centers in planar mechanisms, the instantaneous poles (or instant poles, in brief) can be used for kinematic analysis in spherical mechanisms. One of the mandatory steps in this analysis is the determination of the location of these poles. This paper presents a theorem showing analytically that the locus of an unknown secondary instant pole in two-degree-of-freedom (2-DOF) spherical mechanisms is a great circle (GC). The exact location of the pole on its GC is obtained based on the configuration of the mechanism and velocity ratio of the two inputs. Moreover, using the results of the theorem, a geometrical technique is presented to determine the GC of the pole.

关键词: spherical mechanisms     instantaneous poles     great circle     angular velocity    

Stiffness of a 3-degree of freedom translational parallel kinematic machine

null

《机械工程前沿(英文)》 2014年 第9卷 第3期   页码 233-241 doi: 10.1007/s11465-014-0312-z

摘要:

In this paper, a typical 3-degree of freedom (3-DOF) translational parallel kinematic machine (PKM) is studied and analyzed whose tool platform has only translations along X-Y- and Z-axes. It consists of three limbs, each of which have arm and forearm with prismatic-revolute-revolute-revolute (PRRR) joints. Inverse kinematics analysis is carried out to find the slider coordinates and joint angles for a given position of tool platform. Stiffness modeling is done based on the compliance matrices of arm and forearm of each limb. Using the stiffness modeling the variations of minimum and maximum translational stiffness in the workspace are analyzed. For various architectural parameters of the 3-DOF PKM the tendency of variations on the minimum and maximum stiffness over the entire workspace is studied; and also the deflections of the tool platform along XY, and Z directions with respect to various forces are presented.

关键词: 3-DOF translational PKM     inverse kinematics     stiffness modeling     translational stiffness    

A survey of instantaneous poles for a class of two-degree-of-freedom spherical mechanisms

Soheil ZARKANDI

《机械工程前沿(英文)》 2014年 第9卷 第4期   页码 344-353 doi: 10.1007/s11465-014-0320-z

摘要:

This paper is a detailed exploration of instantaneous poles for a class of two-degree-of-freedom (two-DOF) spherical mechanisms (SMs) with seven links or bars. For two-DOF SMs, the secondary instantaneous poles (the ones which cannot be found by direct inspection) must lie on the specified great circles. For many of these mechanisms, however, some of these great circles cannot be obtained by a direct application of Aronhold-Kennedy theorem. This paper presents geometrical and analytical techniques to locate these unknown great circles for three topologies of seven-bar two-DOF SMs.

关键词: spherical mechanisms     instantaneous poles     Aronhold-Kennedy theorem     great circles     pencil of meridian    

Drive system design and error analysis of the 6 degrees of freedom segment erector of shield tunneling

Hu SHI, Guofang GONG, Huayong YANG

《机械工程前沿(英文)》 2011年 第6卷 第3期   页码 369-376 doi: 10.1007/s11465-011-0223-1

摘要:

Focusing on a segment erector of a shield-tunneling machine developed with 6 degrees of freedom (DOF) and controlled by electro-hydraulic proportional systems, the kinematics of the segment erection process is presented. The perturbation method in the error analysis is introduced to establish the position and attitude error model, considering a number of factors such as the hydraulic drive, control accuracy, and tolerance in manufacturing and assembly. Dynamic simulations are carried out to obtain the controlling precision of electrohydraulic drive systems. Formulas for calculating the position and attitude error of the grip hand of the segment erector are derived. The calculation results verify the practicality and effectiveness of the error analysis, providing a foundation for practical designing, manufacturing, and assembling of the segment of the erecting mechanism.

关键词: shield tunneling machine     segment erector     kinematics     position and attitude precision    

An efficient method for the dynamic interaction of open structure-foundation systems

LIU Jingbo, GU Yin, LI Bin, WANG Yan

《结构与土木工程前沿(英文)》 2007年 第1卷 第3期   页码 340-345 doi: 10.1007/s11709-007-0045-8

摘要: The structure-foundation system is transformed from an original open system into an approximately hermetic system through a viscous-spring artificial boundary. In addition, the seismic wave scattering problem is changed to a wave source problem by employing an equivalent seismic wave input method. Subsequently, the modal superposition method is adopted to solve the approximated hermetic system. This procedure is highly efficient in analyzing dynamic structure-foundation interaction problems in the time domain. Two numerical examples are presented to illustrate the characteristics of the proposed method: one is a wave source problem in 2-dimensions (2-D) elastic semi-infinite space, and the other is a dynamic structure-foundation interaction problem under seismic excitations. Compared with the traditional direct step-by-step integration method, the proposed method, with a sufficient number of modes included, can significantly reduce the computational time with almost the same precision. The results also indicate that the proposed method is more advantageous for solving large structure-foundation systems of many degrees of freedom.

关键词: structure-foundation interaction     superposition     interaction problem     freedom     efficient    

Development of dimensionless P-I diagram for curved SCS sandwich shell subjected to uniformly distributed blast pressure

Yonghui WANG, Ximei ZHAI

《结构与土木工程前沿(英文)》 2019年 第13卷 第6期   页码 1432-1445 doi: 10.1007/s11709-019-0566-y

摘要: The curved steel-concrete-steel (SCS) sandwich shell was recently proposed to resist blast loading and it showed better blast resistant performance as compared to flat SCS sandwich shell via developing compressive force along the shell. In this paper, a dimensionless Pressure-Impulse (P-I) diagram was constructed as a convenient tool to predict the damage level of curved SCS sandwich shell subjected to uniformly distributed blast loading. The curved SCS sandwich shell was equivalent to a single-degree-of-freedom (SDOF) system and the equation of motion was established by employing the Lagrange’s equation. To construct the dimensionless P-I diagram, the energy balance method was utilized to yield the pressure and impulse asymptotes and the responses in the dynamic response regime were obtained via employing the SDOF method. Then, the finite element method was employed to validate the developed dimensionless P-I diagram. Finally, the procedures of using the constructed dimensionless P-I diagram to quickly conduct the blast resistant design of curved SCS sandwich shell were presented.

关键词: blast loading     curved steel-concrete-steel sandwich shell     Pressure-Impulse diagram     single-degree-of-freedom method     finite element analysis    

Regional seismic-damage prediction of buildings under mainshock–aftershock sequence

Xinzheng LU, Qingle CHENG, Zhen XU, Chen XIONG

《工程管理前沿(英文)》 2021年 第8卷 第1期   页码 122-134 doi: 10.1007/s42524-019-0072-x

摘要: Strong aftershocks generally occur following a significant earthquake. Aftershocks further damage buildings weakened by mainshocks. Thus, the accurate and efficient prediction of aftershock-induced damage to buildings on a regional scale is crucial for decision making for post-earthquake rescue and emergency response. A framework to predict regional seismic damage of buildings under a mainshock–aftershock (MS–AS) sequence is proposed in this study based on city-scale nonlinear time-history analysis (THA). Specifically, an MS–AS sequence-generation method is proposed to generate a potential MS–AS sequence that can account for the amplification, spectrum, duration, magnitude, and site condition of a target area. Moreover, city-scale nonlinear THA is adopted to predict building seismic damage subjected to MS–AS sequences. The accuracy and reliability of city-scale nonlinear THA for an MS–AS sequence are validated by as-recorded seismic responses of buildings and simulation results in published literature. The town of Longtoushan, which was damaged during the Ludian earthquake, is used as a case study to illustrate the detailed procedure and advantages of the proposed framework. The primary conclusions are as follows. (1) Regional seismic damage of buildings under an MS–AS sequence can be predicted reasonably and accurately by city-scale nonlinear THA. (2) An MS–AS sequence can be generated reasonably by the proposed MS–AS sequence-generation method. (3) Regional seismic damage of buildings under different MS–AS scenarios can be provided efficiently by the proposed framework, which in turn can provide a useful reference for earthquake emergency response and scientific decision making for earthquake disaster relief.

关键词: regional seismic damage prediction     city-scale nonlinear time-history analysis     mainshock–aftershock sequence     multiple degree-of-freedom (MDOF) model     2014 Ludian earthquake    

Application of consistent geometric decomposition theorem to dynamic finite element of 3D composite beam based on experimental and numerical analyses

Iman FATTAHI, Hamid Reza MIRDAMADI, Hamid ABDOLLAHI

《结构与土木工程前沿(英文)》 2020年 第14卷 第3期   页码 675-689 doi: 10.1007/s11709-020-0625-4

摘要: Analyzing static and dynamic problems including composite structures has been of high significance in research efforts and industrial applications. In this article, equivalent single layer approach is utilized for dynamic finite element procedures of 3D composite beam as the building block of numerous composite structures. In this model, both displacement and strain fields are decomposed into cross-sectional and longitudinal components, called consistent geometric decomposition theorem. Then, the model is discretized using finite element procedures. Two local coordinate systems and a global one are defined to decouple mechanical degrees of freedom. Furthermore, from the viewpoint of consistent geometric decomposition theorem, the transformation and element mass matrices for those systems are introduced here for the first time. The same decomposition idea can be used for developing element stiffness matrix. Finally, comprehensive validations are conducted for the theory against experimental and numerical results in two case studies and for various conditions.

关键词: composite beam     dynamic finite element     degrees of freedom coupling     experimental validation     numerical validation    

二自由度精确解耦离散复矢量永磁同步电机电流控制器 None

Meng WANG, Jia-qiang YANG, Xiang ZHANG, Chang-sheng ZHU

《信息与电子工程前沿(英文)》 2018年 第19卷 第4期   页码 569-581 doi: 10.1631/FITEE.1601390

摘要: 电流控制器性能对永磁同步电机驱动的影响至关重要,然而,在数字处理器中采用传统的连续域电流控制器不能使系统达到完全解耦,这使得电流控制器性能会随电机转速而变化。为提高电流控制器性能,提出一种利用精确离散复矢量模型在离散域直接设计电流控制器的方法。首先,针对变流器输出电压和电机反电势的不同特性推导出永磁同步电机的精确离散模型。然后,根据该模型设计出三阶形式精确解耦二自由度电流控制器,该控制器在配置系统闭环极点时自由度更高。针对两种不同的对消零极点位置选取方案,借助复矢量根轨迹和灵敏度函数对其抗干扰性和参数敏感度进行考察,结果表明两种方案各有优势。最后,在2.5 kW永磁同步电机实验台上验证了所提电流控制器设计方法的有效性。

关键词: 永磁同步电机;离散电流控制器;复矢量    

六自由度光栅干涉仪中的无偏溯源角表达法 Research Article

常笛1,2,胡鹏程1,2,谭久彬1,2

《信息与电子工程前沿(英文)》 2021年 第22卷 第12期   页码 1551-1684 doi: 10.1631/FITEE.2000432

摘要: 光栅姿态角表达方法是六自由度光栅干涉测量的重要课题,但仅有少量相关研究。目前,广泛用于航空航天、导航和机器人领域的导航角(roll-pitch-yaw)被引入六自由度光栅干涉测量领域。然而,因导航角存在固有旋转顺序,在描述绕多个测量轴的复杂旋转时会引起溯源偏差,且该偏差随光栅偏摆角度增加而增大,并不符合干涉系统中的精确定义。基于机器人领域的融合角(fused angles)表达法,本文提出“无偏溯源角(fused-like angles)”表达法,因无偏溯源角不会引起溯源偏差,更加符合光栅干涉仪中的定义,从而更适合六自由度测量。提出的无偏溯源角已应用于六自由度光栅干涉的运动模型和解耦算法研究。

关键词: 无偏溯源角;光栅干涉仪;六自由度测量;角度表达方法    

三自由度混合磁轴承无模型自适应控制系统 Article

Ye YUAN, Yu-kun SUN, Qian-wen XIANG, Yong-hong HUANG, Zhi-ying ZHU

《信息与电子工程前沿(英文)》 2017年 第18卷 第12期   页码 2035-2045 doi: 10.1631/FITEE.1700324

摘要: 由于气隙磁场分布不均以及未建模动态性,数学模型不再适用于磁力轴承系统。基于错误数学模型的系统控制会表现出低响应和高颤动。为解决这一问题,本文提出一种三自由度混合磁轴承无模型自适应控制系统。该控制系统仅与控制电流和轴承的平衡位置有关。其参数估计算法的设计与模型无关,直接基于输入和输出数据的伪偏导数。本文通过不同直径的辅助轴承分析了三自由度混合磁轴承转子悬浮区域,以及通过两种不同的操作系统具体分析无模型自适应控制系统的可行性。模拟和实验结果表明,该三自由度混合磁轴承无模型自适应控制系统具有响应速度快,稳态误差小,和稳定性好等优势。

关键词: 模型自适应控制;混合磁轴承;非线性区域;快速响应;高稳定性    

标题 作者 时间 类型 操作

Error analysis and optimization of a 3-degree of freedom translational Parallel Kinematic Machine

null

期刊论文

Singularity loci of an orthogonal spherical two-degree-of-freedom parallel mechanism

Jialun YANG, Feng GAO,

期刊论文

On the location of the secondary instantaneous poles in two-degree-of-freedom spherical mechanisms

Soheil ZARKANDI

期刊论文

Stiffness of a 3-degree of freedom translational parallel kinematic machine

null

期刊论文

A survey of instantaneous poles for a class of two-degree-of-freedom spherical mechanisms

Soheil ZARKANDI

期刊论文

Drive system design and error analysis of the 6 degrees of freedom segment erector of shield tunneling

Hu SHI, Guofang GONG, Huayong YANG

期刊论文

An efficient method for the dynamic interaction of open structure-foundation systems

LIU Jingbo, GU Yin, LI Bin, WANG Yan

期刊论文

Development of dimensionless P-I diagram for curved SCS sandwich shell subjected to uniformly distributed blast pressure

Yonghui WANG, Ximei ZHAI

期刊论文

Regional seismic-damage prediction of buildings under mainshock–aftershock sequence

Xinzheng LU, Qingle CHENG, Zhen XU, Chen XIONG

期刊论文

Application of consistent geometric decomposition theorem to dynamic finite element of 3D composite beam based on experimental and numerical analyses

Iman FATTAHI, Hamid Reza MIRDAMADI, Hamid ABDOLLAHI

期刊论文

二自由度精确解耦离散复矢量永磁同步电机电流控制器

Meng WANG, Jia-qiang YANG, Xiang ZHANG, Chang-sheng ZHU

期刊论文

六自由度光栅干涉仪中的无偏溯源角表达法

常笛1,2,胡鹏程1,2,谭久彬1,2

期刊论文

三自由度混合磁轴承无模型自适应控制系统

Ye YUAN, Yu-kun SUN, Qian-wen XIANG, Yong-hong HUANG, Zhi-ying ZHU

期刊论文