共查询到17条相似文献,搜索用时 156 毫秒
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多臂机器人关节间的碰撞检测研究 总被引:1,自引:0,他引:1
将多臂机器人各运动关节简化为具有一定直径的圆柱体,通过计算两圆柱体中心线间最短距离来进行机器人的碰撞检测研究.在此过程中,首先通过总结提炼两空间线段间的相互位置关系,在进行解析、推导的基础上,提出了8个有意义的解析几何推论,直接可得出两空间线段间的最短距离,然后根据得出的结果,设计了一个机器人运动关节间的碰撞检测算法.该算法程序设计简单,计算量小,能有效地满足实际应用需要. 相似文献
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对京剧机器人双臂实时碰撞检测的方法进行了研究。首先,通过机器人运动学求出各关节坐标系间的变换矩阵,获得手臂各关节点在机器人基坐标系下的矢量坐标;然后,建立手臂的几何模型,通过几何法实时检测两手臂的最短距离Dmin,并与碰撞发生的临界距离dmax进行实时比较,当Dmin〈dmax时,系统发出暂停信号停止手臂运动;最后利用机器人AS语言,实现了最短距离算法和双臂的通讯,验证了双臂实时碰撞检测方法的可行性。 相似文献
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苏俊熊瑞平温记明李云秋谭平 《制造技术与机床》2022,(10):38-45
针对工件打磨工况,设计建立用于打磨的机器人运动学模型,规划机器人运动学轨迹,通过改进粒子群算法优化轨迹曲线,减少机器人运行时间,提高机器人工作效率。首先建立打磨工业机器人空间运动学模型,计算目标点从笛卡尔空间转换到关节空间的逆解,在关节空间中利用“三次-五次-三次”三段多项式曲线对所求逆解进行轨迹规划,以轨迹运动时间最短作为优化目标。利用融合免疫操作的改进粒子群算法对轨迹曲线进行优化,将改进算法的优化结果与传统粒子群算法进行对比;改进后的新算法改善了粒子群算法易陷入局部最优的问题,适应度结果更好,算法效果更佳。 相似文献
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定义了位姿解耦的冗余自由度机器人位置关节空间流形和姿态关节空间流形,将位置关节空间流形和姿态关节空间流形进行配对得到冗余自由度机器人的自运动流形。利用定义的位置关节空间流形和姿态关节空间流形对七自由度自动铺丝机器人进行分析,分别得出七自由度自动铺丝机器人的位置关节空间流形和姿态关节空间流形,配对以后得出七自由度自动铺丝机器人的自运动流形,并进行了仿真验证,结果表明这种分析方法得到的自动铺丝机器人的自运动流形是正确的,而且对于其他类型位姿解耦的冗余自由度机器人自运动流形分析也是适用的。 相似文献
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Yinggang Li Tianning Chen Xiaopeng Wang Kunpeng Yu Chao Zhang 《Journal of Mechanical Science and Technology》2014,28(6):2017-2024
Impact noise characterized by high peak value and short duration is very common source of noise in the industries and in many cases can be summed up in the noise radiated by collision of two cylinders. In order to precisely predict the impact noise radiated by collision of two cylinders, a modified theoretical prediction model was established based on the Palmgren’s cylinder contact empirical model and acoustics theory. Then a numerical simulation method combining the finite element method (FEM) and the transient boundary element method (TBEM) had been presented to verify the modified theoretical model and further discuss the mechanism of impact noise. Both the contact force and impact noise of collision cylinders by the modified theoretical model were compared with the numerical results as well as the prediction results by the original theoretical model. It indicated that the results by modified theoretical prediction model are in good agreement with the numerical results, indicating better prediction superior to the original model. The impact noise radiated by collision cylinders is attributed to the rigid body acceleration. Furthermore, the experimental validations were conducted to verify the modified theoretical prediction model and numerical simulation results. 相似文献
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Tian Yongtao Li Juan Wang Youqing Li Congxin 《The International Journal of Advanced Manufacturing Technology》2004,23(1-2):110-115
A method to find the principal point of an image plane is proposed in this paper for the case of a pincushion distortion. The analytical foundation of the method is that a pincushion distortion causes a pair of distortion-free parallel lines to become a pair of curves, which are termed conjugate curves in this paper, and the shortest line segment connecting the pair of conjugate curves passes through the principal point. Thus, the principal point can be obtained by computing the intersection point of the shortest line segments of different pairs of conjugate curves. However, the case for a digital image is a bit different from the above. For the same pair of conjugate curves, there is a group of shortest line segments, which is called a shortest segment set. The coincidence region of the shortest segment sets of different pairs of conjugate curves is a polygon, the centroid of which is considered as the principal point. Therefore, the proposed method firstly needs to capture the pincushion-distorted images of some pairs of parallel lines, secondly to find the corresponding polygon and lastly, to calculate the centroid point. A synthetic image and a real image are tested using this method, and the results are satisfying. 相似文献
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Y.-J. Tseng Y.-D. Chen C.-C. Liu 《The International Journal of Advanced Manufacturing Technology》2001,17(11):783-790
To machine a shape incorporating freeform curves, the free-form curves must be approximated and represented in a form suitable
for numerically controlled (NC) tool-path generation. Instead of the commonly used line segment approximation, a new method
using biarc approximation is presented here. The purpose is to reduce sudden changes in tool movement and increase continuity
and smoothness. A biarc can be described as two consecutive circular arcs with an identical tangent at the connecting point.
Therefore, tangent continuity can be maintained. Furthermore, curvature continuity can be improved if the difference between
the two curvatures is minimised. In this research, biarc segments are used to approximate the freeform curves by controlling
the largest deviation distance between the curves and the biarcs. The test results show that the biarc approximation method
generates fewer tool-path segments than the traditional line approximation. The definitions of the biarcs are used to generate
NC tool paths. A new tool-path generation method is developed for processing rough cutting and finish cutting paths. Example
parts modelled with B-spline curves are tested and machined. 相似文献
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Design and simulation for a hydraulic actuated quadruped robot 总被引:1,自引:0,他引:1
Rong Xuewen Li Yibin Ruan Jiuhong Li Bin 《Journal of Mechanical Science and Technology》2012,26(4):1171-1177
This paper describes the mechanical configuration of a quadruped robot firstly. Each of the four legs consists of three rotary
joints. All joints of the robot are actuated by linear hydraulic servo cylinders. Then it deduces the forward and inverse
kinematic equations for four legs with D-H transformation matrices. Furthermore, it gives a composite foot trajectory composed
of cubic curve and straight line, which greatly reduces the velocity and acceleration fluctuations of the torso along forward
and vertical directions. Finally, dynamics cosimulation is given with MSC.ADAMS and MATLAB. The results of co-simulation provide
important guidance to mechanism design and parameters preference for the linear hydraulic servo cylinders. 相似文献
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一种判别空间两线段干涉的快速算法 总被引:8,自引:1,他引:8
在多机械手系统中 ,机械手各杆状关节相互之间在运动过程中极易产生机械干涉 ,快速判别两杆状物体互相产生机械干涉的算法对多机械手系统的动态任务规划具有十分重要的意义。一般的研究方法都是把杆状物体简化为空间线段来进行分析和计算他们之间的距离或者具体的交点位置。实际上 ,判断两空间线段是否产生干涉只需要知道两线段是否存在交点 ,而不需具体计算交点的位置以及两空间线段之间的距离 ,就可判别其干涉状态 ,基于此本文提出了一个极为简单的计算方法 ,该方法利用解析几何中的理论 ,提出了几个基本定义 ,将空间的两杆状物体抽象为线段 ,然后投影到笛卡尔空间直角坐标的三个直角投影面 ,通过一些简单的加减乘除计算 ,就可判别两线段干涉状态。 相似文献
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运用刚性模型测压风洞试验方法对单圆柱、不同间距串列双圆柱和串列三圆柱绕流的时均压力分布与气动力进行了研究。首先,进行单圆柱模型和不同间距串列双圆柱模型的绕流试验,试验的雷诺数为3.4×104;其次,通过与单圆柱进行对比,讨论了气动干扰对串列三圆柱时均压力分布与时均阻力的影响规律;最后,通过与串列双圆柱进行对比,讨论了圆柱的数量对干扰规律的影响。试验结果发现,串列三圆柱的绕流存在两个完全不同的流态,其切换的临界间距(L/D)cr在3.5~4.0之间,两个流态下的时均压力分布与时均阻力存在明显的差异。本研究可对实际工程中串列圆柱结构的风荷载取值提供参考。 相似文献
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Ki Baik Lee Yong Gyun Kim Bong Hwan Kim Young Kil Kwon 《Journal of Mechanical Science and Technology》1990,4(2):115-119
Experimental investigation of the fluid flow and thermal flow pattern around two circular cylinders in cross flow has been
carried out. Reynolds number was varied in the range of 100≦Re≦1000 and the distance between the two cylinders in the interval of 2≦L/D≦4. Velocity and turbulence intensity distributions in the isothermal distribution in the whole x−y thermal flow field was
obtained by double-exposure holographic interferometry. The influences of Reynolds number and the gap spacing between the
two cylinders were investigated. The characteristic flow pattern was found to depend on the distance between the two cylinders.
WhenL≦3D, the wake region between the two cylinders became quasi-stationary. 相似文献