英语科技论文

1、主要内容 期刊分析 题目分析 摘要分析 关键词分析 引言分析 正文分析 结论 附录 参考文献 论文亮点 存在问题 期刊分析 通讯作者 收录与发表 时间 题目分析 “A novel approach”放在最前面可以突出论文重 点，一个“novel”表明是作者的创新，是一个 新的方法，“for”后面理解的是解决的问题， “of”表明研究的机构。题目简单易懂、内容 齐全 A novel approach for forward position analysis of a double-triangle spherical parallel manipulator 研究内容： 位置正解 研究机构：

2、DT球面机构 提出新方法 摘要分析 In this paper, we introduce a new approach for forward position analysis of a double-triangle (DT)spherical parallel manipulator. Utilizing spherical geometry of the manipulator, two coupled trigonometric equations are obtained through using special form of Rodrigues formula . Next

3、, the two coupled equations are solved using Bezouts elimination method which leads to a polynomial of eight degree.Finally, we provide an examplehaving eight real solutions, the polynomial thus being minimal 引出具体 研究问题 阐述具体 研究方法 层次 清晰 明了 Utilizing spherical geometry of the manipulator, two coupled t

4、rigonometric equations are obtained through using special form of Rodrigues formula 利用球面几何得到特殊形式的2个耦合三角公式 Next, the two coupled equations are solved using Bezouts elimination method which leads to a polynomial of eight degree. 通过Bezout的消元法求解，可以得到8次多项式 Finally,we provide an example having eight real

5、solutions, the polynomial thus being minimal 给出一个具有8个解的实例 优点：直切主体 缺点：没有终结 和展望 关键词分析 keywords: Spherical parallel manipulator Forward position analysis Rodrigues formula Bezouts elimination method 研究机构： 球面并联机构 位置正解 Rodrigues公式 Bezout消元 研 究 方 法： 研究 内容 引言分析 Parallel manipulators are closed-loop mechani

6、cal chains, which generally have good performance in terms of accuracy, rigidity and ability to manipulate large loads. These mechanisms consist of two main bodies connected by several legs. One body is assumed to be fixed while the other is regarded as moveable and hence they are respectively calle

7、d base and moving platform. 明确研究领域： A spherical manipulator is one in which the end-effector is moved on the surface of a sphere. In other words, the end -effector can rotate around anyaxis passing through a fixed point, center of sphere. Therefore,a spherical manipulator can be used as a device to

8、orient the endeffector 并 联 机 构 球 面 机 构 引言分析 The forward position analysis (FPA) of spherical parallel manipulator has attracted much attention among researchers. Many studies (Innocenti and Parenti-Castelli,1993; Wohlhart,1994; Gosselin et al., 1992a,b; Gosselin and Gagne, 1995; Di Gregorio, 2003, 2

9、000, 2004; Husain and Waldron, 1992; Huynh and Herve, 2005; Mohammadi Daniali et al., 1993) have addressed this problem for different manipulator architectures. They showed that the FPA of these mechanisms can be solved in echelon form (find all possible solutions of the FPA) 研究现状： 引言分析 The solution

10、 of the FPA for 3-RRR spherical parallel manipulator can be found in the literature.Gosselin et al. (1994) derived at a polynomial of eight degree and gave an example having eight real solutions, the polynomial thus being minimal. Mohammadi Daniali et al. (1993)proposed a spherical doublet riangle p

11、arallel manipulator and solved its direct kinematics problem. They derived at a polynomial of sixteen degree. Coefficientsof the polynomial were too large (more than 100 pages in the mostcompact form). In addition, they gave an example having four real solutions. Also, they showed that the polynomia

12、l leads to a maximumof eight real solutions, the polynomial thus not being minimal. 著名学者的 研究成果 存在问题：系数大， 四个解，多项式不 是最小 引言分析 In this paper, we introduce a new approach for forward position analysis of a double-triangle (DT) spherical parallel manipulator that is optimum. Utilizing spherical geometry o

13、f the manipulator, we will obtain two coupled trigonometric equations using special form of Rodrigues formula (equivalent axisangle representation). Next, we solve the two coupled equations using Bezout elimination method, which leads to a polynomial of eight degree. Lastly, we give an example havin

14、g eight real solutions, the polynomial thus being minimal 引出研究方案 提出方法-球面几何推导-Bezout化解-得出结果-实例验证 正文分析 body DT球面 机构结 构 Rodrigu es公式 Bezout 消元 实例验 证 结论 位置正 解 正文分析-机构结构 动静平台通过三条支链相连，每条支链由 CP-R-CP副组成，CP是一个沿曲线轨迹的 移动副，它可以看做是一个特殊的转动副， 因此，所要研究的DT机构可以看作是一个 典型的3-RRR机构 Spherical double- triangle (DT) parallel m

15、anipulator 求解位置正解的新方法： 定义过球心的15个单位 向量来建立运动学模型 正文分析-机构结构 The corners of the fixed spherical triangle are denoted byPi. Direction of OPi can be defined by unit vector vi Actuators stroke which can travel along the arcPiPi1are defined by ri. The corners of the moving spherical triangle are specified by

16、 Pi.Direction of OQican be defined by unit vector ui. The corner angles of the moving spherical triangle are defined bya1,a2,a3. The arcs of the base triangle,PiPi1, cross over the corresponding arcs of the moving spherical triangle platform,QiQi1,at pointRi. The angular position ofthe actuators are

17、 defined by unit vector ri. Direction of the unit vector is defined along ORi. Furthermore,Ri is a joint, which allows rotationabout ri axis as well as a rotation about the axis that passes through center of sphere,O, and is perpendicular to OQi Qi1plane. The nine unit vectorsvi, ui andri (fori1, 2,

18、 3) help to describe the structure and configuration of the manipulator. Using these unit vectors, six more unit vectors will be defined, in Section4, in order to completethe forward position analysis of the manipulator 作者提出 的方法 正文分析-旋转公式 EEIeQsin)cos1 (),( 2 33 eeeIeQ T sin)cos1 (),( 33 Before pres

19、enting forward position analysis of spherical doubletriangle, it is useful to consider matrix representation of a rotation presented by Rodrigues Rodriguest提出的 旧方法用于新机构 Rodrigues公式 正文分析-位置正解 For any given manipulator, there exist different modeling methods to derive the forward position problem. Amo

20、ng these methods, the method that results in the lowest order polynomial is the super method.Furthermore, the modeling method is optimal if we can find an example where the num- ber of real answers is equal to the order of the polynomial 提出比较各个 方法的标准 多项式的次数低 能够找到符合结果的实例 正文分析-位置正解 ii ii ii ii i rV rV

21、 VV VV W 1 1 ii ii ii ii i ru ru uu uu t 1 1 r ii 必要的 数学推导： 由机构结 构得到。 参数由前面 提到的15个 单位向量 )(sincos )(sincos 111111 111111 rtru wrww 应用Rodriguez得到 推导结果：是 两个三角函数 方程 在这一部分，作者主要是利用Rodrigues公式和机 构结构进行位置正解分析，是一种新方法，同时 利用已有研究成果来解决现有问题，是创新的一 种典型 正文分析-方程消元 Bezout消元法可以将一组多变量的多项式转化为单 变量的多项式。应用这种方法求解方程组那么三角 方程必须变

22、为一组多项式， Bezouts elimination method may be used to reduce a set of polynomials of multiple variables into a polynomial of only onevariable. To apply this method to solve the nonlinear Eqs.(26）and(27), the trigonometric equations must be transformed into a set of polynomials. Bezout 优点 应用前提 2 2 2 2 1

23、2 2 2 1 2 1 2 1 1 2 1 1 1 1 1 cos, 1 2 sin 1 1 cos, 1 2 sin x x x x x x x x )2/tan(),2/tan( 1211 xx 0)()()( 0)()()( 14213 2 212111210 2 29 2 1827 2 26 523 2 2514 2 24 2 1122 2 21 FxFxFxFxFxFxFxFxF FxFxFxFxFxFxFxF 0cossin 0cossin 654 321 ddd ddd 带 入 得到这样两个多项式 应用Bezout消元法，我们可以从方程组中消去x1 0 14213 2 21227

24、 2 26 23 2 2522 2 21 11210 2 29827 2 26 4 2 24122 2 21 14213 2 21211210 2 29 23 2 254 2 24 14213 2 212827 2 26 523 2 25122 2 21 FxFxFFxFxF FxFxFFxFxF FxFxFFxFxF FxFFxFxF FxFxFFxFxF FxFxFFxF FxFxFFxFxF FxFxFFxFxF 因此，我们可以得到下面的因此，我们可以得到下面的8 8次单变量多项式次单变量多项式： As can be seen, Eq.(38) is an eight degree po

25、lynomial where Mohammadi Daniali et al. (1993)arrived at a sixteen degree polynomial.This shows improvement in the modeling method.Furthermore, the coefficients of the polynomial shown in Eq.(38)are significantly smaller than the coefficients derived by Daniali.This greatly decreases computational t

26、ime, which is necessary for dynamics and simulation. It is also important to point out thatEq.(38) admits eight solutions, which may be real and/or complex. The modeling method is therefore optimal since we can find an example having eight real solutions 从公式 得到结论 八次多项式 与 M.D 结果 比较， 有三 个优 点 实例分析 通过实例

27、 验证原理 的正确性 固定平台的结构参数 设平面OP1P2位于XY平面，OP1P3可以是任 何平面，为了简化，假设它位于XZ平面， P1P3=P2P3=/2，P2P1=3/2. 动平台的结构参数 球面三角形可以由两个角度和它们之间的弧长 来确定。因此假设弧的长度和动平台的角度如下： 驱动器参数 假设驱动器的当前位置为：， 假设圆的半径为1 12/7 2121 QQ 12/5, 2/ 321 将给定参数 带入计算公式 求得8个解 第1解 第2解 第3解 第4解 结论 We have presented a new approach for solving the forward position

28、 problem of a DT spherical parallel manipulator. First, we developed the kinematics model of the manipulator using unit vectors. Because of the spherical nature of the manipulator, all these unit vectors are on axes which pass through the origin of the sphere. Special form of Rodrigues formula was t

29、hen used to show relationship between these unit vectors, which resulted in two coupled trigonometric equations. Next, using Bezouts elimination method, the two coupled equations were reduced to a polynomial of eight degree. An example having eight real solutions was provided. Therefore, the polynom

30、ial is minimal which indicates the solution method is optimum. Lastly, four of the eight solutions were shown graphically 结论 提出求提出求DT球面并联机构位置正解的新方法球面并联机构位置正解的新方法。首先。首先 定义单位向量建立运动学模型，由于机构的特殊定义单位向量建立运动学模型，由于机构的特殊 性，所有的向量通过球心。其次用在这些向量之性，所有的向量通过球心。其次用在这些向量之 间间用用Rodrigues公式建立方程公式建立方程。最后用。最后用Bezout消元法消元法

31、将将一组多变量的多项式转化为单变量的一组多变量的多项式转化为单变量的8次多项式。次多项式。 同时给出一个同时给出一个实例实例来证明计算结果是正确的来证明计算结果是正确的 缺点：没有给出未来工 作展望 优点：思路清晰，方法 新颖 附录 附录给出了多项式的8个系数的表达式 致谢 文章没有致谢 参考文献 参考文献中主要有Di Gregorio和Gosselin的研究 成果，是具有代表性的文献，同时也调研了其他 人研究的成果。 1Di Gregorio, R., 2000. A new parallel wrist employing just revolute pairs: the 3-RUUwri

32、st. Robotica 19 (3), 305309 2Di Gregorio, R., 2001. Kinematics of a new spherical parallel manipulator with three equal legs: the 3-URC wrist. J. Rob. Syst. 18 (5), 213219 3Di Gregorio, R., 2003. Kinematics of the 3-UPU wrist. Mech. Mach. Theory 38,253263 4Di Gregorio, R., 2004. The 3-RRS wrist: a new, simple and non- overconstrained spherical parallel manipulator. ASME J. Mech. Des. 127, 850 5Gosselin, C.M., Angeles, J., 1989. The optimum kinematic design of a spherical threedegree-of-freedom parallel manipulator. ASME J. Mech. Des. 111 (2),