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新型机器人6维力/力矩传感器结构的刚度性能指标分析 总被引:7,自引:1,他引:6
提出了一种新颖的6维力/力矩传感器并联结构,应用并联机器人机构学理论求出其刚度矩阵,定义其刚度性能指标,并对其刚度性能指标进行分析计算,为该传感器的设计与应用提供理论依据。分析计算结果表明,该并联结构的6维力/力矩传感器是位移刚度和扭转刚度各项同性的,可应用到机器人手腕、手指和其它使用多维力/力矩传感器的场合。 相似文献
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多轴数控加工刀具姿态优化及其刚度性能指标分析 总被引:1,自引:0,他引:1
在变形叠加基本原理的基础上,对多轴数控机床刚度模型进行了研究,得到了多轴数控加工刀具姿态优化的物理约束条件。在被加工复杂曲面刀具轨迹上,根据多轴机床综合刚度模型计算机床刚度性能指标,并在刀具可达工作空间中优化多轴机床刚度性能指标,以确定对应的刀具姿态。对基于多轴机床刚度模型的刀具姿态优化作了详细的讨论,分析了任务空间的力椭球特性,提出了面向切削加工的多轴机床刚度性能指标,并将其用于指导刀具姿态规划。
multi-axis NC machine tool;stiffness;tool posture;force ellipsoid 相似文献
multi-axis NC machine tool;stiffness;tool posture;force ellipsoid 相似文献
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机床静刚度是机床的重要性能指标之一,其试验与评价对机床结构的改善和加工精度的提高有着重要意义。以某型号立式加工中心为研究对象,通过Creo软件建立三维模型,利用有限元分析技术仿真分析数控机床结构。同时,基于LabVIEW设计一个机床静刚度测量系统,并对立式加工中心进行静刚度试验。试验结果与仿真结果误差为7.2%,验证了有限元模型的准确性。试验的机床刚度非线性度为±3%,说明该机床的性能较为稳定。 相似文献
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基于全雅可比矩阵和虚功原理建立了5-UPS/PRPU冗余驱动并联机床的完整刚度模型。首先基于螺旋理论推导出约束分支中的约束雅可比矩阵;然后锁定分支中的主动副并利用互易积原理求得驱动雅可比矩阵,最后提出了冗余驱动雅可比矩阵。利用约束力、驱动力和冗余驱动力与外力的映射关系,结合虚功原理,得到系统整体刚度矩阵。考虑虎克铰、轴承等传动部件的轴向变形对分支轴向刚度的影响,构造了各个分支的轴向刚度模型。借助激光跟踪仪对所建立的刚度模型进行了实验测试。结果表明:该刚度模型的误差为2%~5%,验证了理论分析的可靠性。在此基础上,以机床的线刚度和角刚度的最小值为刚度性能指标,分析了其在工作空间内的分布情况。分析显示:机床线刚度的最小值主要分布在Y轴两侧,角刚度的最小值则主要分布在-0.05≤z≤0.05m和-0.11≤y≤-0.05m,因此,在进行并联机床工具规划时应该尽量避免该区域。文中内容可为并联机床刀具运动轨迹的优化提供参考依据。 相似文献
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刚度是并联机构重要性能指标,为了评价并联机构刚度,提出了一种刚度评价方法.基于3-RRR机构的逆运动学模型,推导出其雅可比矩阵.在力雅可比矩阵的基础上,给出了刚度评价指标,该指标不仅适用于3-RRR并联机构,而且可以应用于其它并联机构.将提出的刚度指标应用于3-RRR并联机构,数值仿真结果表明3-RRR机构在工作空间中具有对称的刚性. 相似文献
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提出一种基于运动学、刚度和动力学性能的并联机构有序递进三级优化策略,即分别应用遗传算法(GA)、粒子群算法(PSO)、差分进化算法(DE)三种智能算法,以工作空间性能和运动/力传递性能为目标的尺度参数优化方法,又在优化尺度参数基础上,以机构承载刚度和整体刚度为目标进行构件截面参数优化,再在优化尺度参数和截面参数基础上,以动力学灵巧度和能量传递效率为目标进行构件质量参数优化,从而使得机构的尺度、截面及质量参数达到最优。以一种零耦合度三平移一转动(SCARA)并联操作手为例,运用矢量法建立了并联操作手的运动学模型,通过工作空间性能和运动/力传递性能两个运动学指标,优化其尺度参数;运用虚拟弹簧法得到该并联操作手的刚度模型,通过对三维模型的参数识别得到其柔度矩阵,并分析了承载刚度、整体刚度两个刚度性能指标,优化了构件的截面参数;利用动力学普遍方程导出了该并联操作手的动力学模型,通过动力学灵巧度和能量传递效率两个动力学性能指标,优化了构件的质量参数。最终,该并联操作手的运动学、刚度和动力学综合性能达到最优,也得到了一些尺度、截面及质量参数的设计准则。 相似文献
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针对并联机构中机构的刚度和弹性变形随外载荷变化的问题,以3/6-SPS 并联机构为例,采用解析法求解分析其总刚度矩阵和弹性变形。首先,分析该并联机构受力位置并确定驱动力及其姿态;然后,分析该机构的驱动约束分支的弹性变形,导出驱动约束分支的伴随矩阵;最后求解出该并联机构的总刚度矩阵和弹性变形。得到结论:当建立3/6-SPS 并联机构的总刚度矩阵和求解弹性变形时,必须理清刚度和位姿、广义六维力之间的关系。 相似文献
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Enhanced stiffness modeling of manipulators with passive joints 总被引:3,自引:0,他引:3
The paper presents a methodology to enhance the stiffness analysis of serial and parallel manipulators with passive joints. It directly takes into account the influence of external and internal loadings on the manipulator configuration and, consequently, on its Jacobians and Hessians. The main contributions of this paper are the introduction of a non-linear stiffness model for the manipulators with passive joints, a relevant numerical technique for computing the Cartesian stiffness and stability criteria for configurations of the kinematic chains. Within the developed technique, the manipulator elements are presented as pseudo-rigid bodies separated by multidimensional virtual springs and perfect passive joints. Simulation examples are presented that deal with parallel manipulators of the Ortholide family and demonstrate the ability of the developed methodology to describe non-linear behavior of the manipulator structure such as a sudden change of the elastic instability properties (buckling). 相似文献
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Generalized Jacobian analysis of lower mobility manipulators 总被引:1,自引:0,他引:1
Exploring screw theory through the formalities of linear algebra, this paper presents a general approach for Jacobian analysis of lower mobility manipulators. Given the definitions of twist/wrench spaces and their subspaces of the end-effector, the underlying relationships amongst these subspaces are identified using the virtual work principle. Using the orthogonal and dual properties of these subspaces and variational representations to account for the permitted and restricted instantaneous motions of the end-effector, a rigorous general and systematic procedure for the formulation of a generalized Jacobian is proposed. The merit of the generalized Jacobian is that it allows the first order kinematic and static modeling (velocity, accuracy, force and stiffness) to be integrated into a unified mathematical framework, so standardizing the modeling procedure and improving the efficiency of design and analysis. The generalized Jacobians for the three well-known parallel manipulators are derived as examples to illustrate the generality and effectiveness of this approach. 相似文献
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Whee-Kuk Kim Jun-Yong Lee Byung Ju Yi 《Journal of Mechanical Science and Technology》1997,11(4):408-418
A planar three degree-of-freedom parallel manipulator has been extensively studied as the fundamental example of general parallel
manipulators. It is proven from previous work (Kim, et. al., 1996) that when three identical joint compliances are attached
to the three base joints of the mechanism in its symmetric configurations, this mechanism possesses a completely decoupled
compliance characteristic at the object space, which is the important operational requirement for an RCC device. In this work,
we are concerned with the adjustability of the output compliance matrix of this mechanism, by employing redundancy on either
joint compliances or on actuators. Two approaches are suggested to achieve this purpose. In the first approach, the stiffness
modulation is achieved through purely redundant passive springs or decoupled feedback stiffness gains. In the second approach,
stiffness modulation is achieved through antagonistic actuation of the system actuators. General stiffness models are derived
for both cases. Based on these stiffness models, stiffness modulation algorithms are formulated. The capability of actively
adjustable stiffness will be very effective in several robotic applications. 相似文献
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V. A. Glazunov S. Briot V. Arakelyan M. M. Gruntovich Ngyuen Minh Thanh 《Journal of Machinery Manufacture and Reliability》2008,37(2):176-185
Manipulators of a new class characterized by a parallel-cross structure are considered. Kinematic chains located according to the principles of a parallel structure are linked with cross chains that contain drives or impose constraints. Such a layout may facilitate a decrease in the dimensions of the foundation and the output link and an increase in stiffness. A classification of the proposed mechanisms is presented. The working volumes of the new manipulators and those of the most popular manipulators based on a parallel structure (the Gough-Stewart platform) are compared. 相似文献
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Fang Hairong Fang Yuefa Guo ShengSchool of Mechanical ElectronicControl Engineering Beijing Jiaotong University Beijing China 《机械工程学报(英文版)》2004,17(4):486-489
Structural synthesis for 4-DOF parallel manipulators using screw theory is systematically studied. Motion properties and constraint conditions of 4-DOF parallel manipulators according to the relationship between screw and reciprocal screw are analyzed. Mathematical expressions for constraint screws and twist screws of moving platform are constructed, and all possible limbs, which provide one or more force constraints, are enumerated. Finally, a parallel manipulator with 3-rotation-DOF and 1-translation-DOF is used as an example to describe the synthesis procedure for symmetrical and non-symmetrical 4-DOF parallel manipulators. 相似文献
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为快速建立基于三自由度并联机构2RPU/UPR构造出的五自由度混联机器人的解析刚度模型,首先对混联机器人的结构进行了描述;然后基于串联和并联结构独立求解思想,建立了混联机器人的位置反解模型;再对混联机器人的结构进行简化处理,分别求解并联部分与串联部分两子系统的静刚度模型,从构造系统的力旋量系和弹性变形协调条件入手,简单且快速地建立了混联机器人的整体刚度模型;最后构造混联机器人的等效三维模型,运用有限元和MATLAB软件,对典型位姿下混联机器人受外力/力矩产生的微位移进行仿真验证,并给出了整机静刚度在任务空间中随位形变化分布图。通过仿真与理论计算的对比分析,验证了该混联机器人理论刚度模型的正确性。 相似文献