应用于自动化生产线的视觉机器人系统

应用于自动化生产线基于眼固定安装方式的机器人定位系统，提出了一种方便有效的手眼标方法，通过最小二乘法求解手眼坐标的变换关系，再根据工作台平面与摄像机成像模型的约束关系，求解出目标物体的三维位姿，并最终实现了机械手的精确定位。     

A multi-level optimization methodology for determining the dextrous workspaces of planar parallel manipulators

A numerical multi-level optimization methodology is proposed for determining dextrous workspaces of 3-degree-of-freedom (3-dof) planar parallel manipulators, in which it is required that at any point within the workspace, the manipulator is able to assume any orientation in a specified range. The method starts by finding a single initial point on the boundary of the dextrous workspace. This first stage requires the successive solution of three separate optimization sub-problems, where the evaluation of the objective function for the second problem and the constraint functions in the third problem are determined by the solution of appropriate optimization problems at a lower level. Once the boundary point is identified, further successive points along the dextrous workspace boundary are traced by the application of the so-called chord method. In the latter procedure, the determination of each successive boundary point is also obtained via a constrained optimization problem, where the constraint functions are again evaluated via the solution of an optimization problem at a lower level. The proposed method is illustrated by its successful application to three different manipulator design geometries, and for various ranges of dexterity. An abbreviated version of this paper was presented at the 5th ASMO UK/ISSMO conference on Engineering Design Optimization, Stratford upon Avon, UK, July 12–13, 2004.     

机器人服务角的分析

本文着重解决机器人绕工作空间内任一点的服务角计算问题.首先,本文分析了服务区的一些性质;其次,讨论了机器人非线性方程组的解;最后,提出了一种求解服务区边界及灵活工作空间特性系数的新方法.     

机器人尺度综合的一种方法

本文研究了机器人的尺度综合问题。文中建立了在直角坐标系中表示的,联系机器人极限距离位置与关节位置的约束方程组。导出了优化综合的数学模型。提出了优化的目标函数和可能选择的设计变量。本文所提出的方法可以报据给定的边界轮廓线上的一系列点来综合机器人的运动学参数,因而是一种切实可行的方法。最后给出了一个数字实例以说明这种方法。     

λ型并联机床的工作空间分析

针对一种双直线电机驱动的平面并联机床的λ型机构模型,给出了机床主运动平面机构的运动特性,分析研究了λ型平面四杆机构的工作空间。机构的工作空间与机构滑鞍的行程以及机构的尺寸有关,分别给出了各种情况的工作空间几何形状。     

一种欠约束丝牵引并联机构工作空间的分析方法

针对光学悬丝吊架试验台系统应用的六丝牵引的并联机构,提出了运用维数缩减法求解欠约束六自由度并联机构工作空间的方法,并利用提出的衡量工作空间质量的评价指标ks,通过Matlab仿真分析了机构结构参数及预紧力系数等对其工作空间的影响趋势,最后经过多次计算对比,得出机构各参数的最优组合,获得最大工作空间,从而为下一步的实际测试试验奠定基础。     

考虑工作空间与力传递效率的新型五自由度混联机器人设计与分析

提出了一款构型为R(2RPR)R/SP+RR的新型五自由度混联机器人,对其性能进行分析,并依据工作空间与力传递效率性能指标进行尺寸优化,获得了关键设计尺寸;在此基础上,进行混联机器人本体结构设计与刚度分析,并与其他同类典型机器人刚度进行了对比;最后分析了混联机器人工作空间,提出一种工作空间搜索方法,分析了机器人在不同布局情况下工作空间是否满足预期。     

Dynamic equipment workspace generation for improving earthwork safety using real-time location system

Earthwork equipment accounts for a large proportion of the fatalities on construction sites. According to the U.S. Bureau of Labor Statistics, in the period between 1992 and 2002, struck by vehicles and struck by objects (e.g., vehicle parts, vehicle loads, or falling vehicles) were identified as the causes of 30% and 24% of fatal equipment-related accidents on excavations sites, respectively. It is therefore of a paramount importance to improve the safety of construction sites by increasing the peripheral awareness of the operators of earthwork equipment. Several research works have investigated numerous collision avoidance systems that exploit real-time location systems and proximity measurements to mitigate the risk of accidents on excavation sites. However, these systems often detect collisions based on using the workspaces that only account for the geometry and the degrees of freedom of the equipment, and thus disregard the state-dependent characteristics of equipment. This results in reserving a large space for every piece of equipment, which reduces the applicability of these systems in congested sites. Therefore, this paper proposes a novel method for generating dynamic equipment workspaces based on the continuous monitoring of a spectrum of equipment-related information, i.e., the current pose/state of the equipment, and the speed characteristics of each movement. This method uses the required operation stoppage time to determine how much space needs to be reserved for each piece of equipment. A case study is conducted to validate the proposed method. It is shown that the proposed method has a strong potential in capturing the hazardous areas around the equipment and triggering warnings in view of the impending movements of various pieces of equipment. Also, the proposed method proved to have potential applications in actual projects in congested sites where space is limited.     

A multilevel calibration technique for an industrial robot with parallelogram mechanism

This paper presents a multilevel calibration technique for improving the absolute accuracy of an industrial robot with a parallelogram mechanism (ABB IRB2400). The parallelogram structural error is firstly modeled based on the partial differential of the position function of a general four-bar linkage and the linearization of the position constraints of the parallelogram mechanism, the model coefficients are fitted from experimental data. Secondly, an absolute kinematic calibration model is established and resolved as a linear function of all the kinematic parameters, as well as the base frame parameters and tool parameters. Finally, contrary to most other similar works, the robot joint space (rather than Cartesian space) is divided into a sequence of fan-shaped cells in order to compensate the non-geometric errors, the positioning errors on the grid points are measured and stored for the error compensation on the target points. After the multilevel calibration, the maximum/mean point positioning errors on 284 tested configurations (evenly distributed in the robot common workspace) are reduced from 1.583/0.420 mm to 0.172/0.066 mm respectively, which is almost the same level as the robot bidirectional repeatability.     

虎克铰工作空间研究及其在6-HTRT并联机器人中的应用

虎克铰作为一种能够提供两个自由度的铰链机构，在各种机构形式的并联机器人中得到了广泛的应用。对虎克铰的工作原理和工作空间作了研究和仿真，研究结果用于6－HTRT并联机器人的尺度综合，使得并联机器人的工作空间范围不受虎克铰运行副转角范围的限制，工作空间体增大，并联机器人的工作空间算法限制因素减少，运动控制算法简单，提高了并联机器人机构性能。