Trajectory coordination planning and control for robot manipulators in automated material handling and processing

Motion coordination planning and control play a crucial role in robot application to Cartesian task operations with taking into account kinematics and dynamics constraints. This paper presents a unified approach to coordination planning and control for robot position and orientation trajectories in Cartesian space. The concept of generalised robot pose is defined as the robot configuration consisting of position and orientation, in which the orientation is described by a vector equivalent to the rotational angular displacement. The robot pose ruled surface is formed as a three-dimensional motion locus of its configuration vector. The unified treatment of the end-effector positions and orientations is based on the robot pose ruled surface concept and used in trajectory interpolations. The coordination planning of pose trajectories for the robot end effector is accomplished by generating and optimising the pose ruled surface under the constraints of kinematics and dynamics performances. The coordination control is implemented through controlling the motion laws of two end points of the orientation vector and calculating the coordinates of instantaneous corresponding points. The simulation experiment using PUMA 560 robot in arc welding and surface finishing processes are carried out to verify the feasibility of the proposed approach and demonstrate the capabilities of generation and control models.     

基于人工生命算法的并联机器人最优轨迹规划

基于机器人直纹面概念和人工生命算法,提出一种并联机器人位姿轨迹最优规划方法.应用计算几何中的三维直纹面生成原理,对机器人末端执行器的位置和姿态进行统一描述.考虑到机器人姿态直纹面面积及其变化率能够反映和评价机器人的运动学和动力学性能,通过求解等效角位移矢量在空间的运动轨迹形成的三维直纹曲面面积及其变化率,并将其作为泛函的泛函极值,同时考虑运动时机器人的灵活度,建立机器人位置和姿态轨迹优化的数学模型.采用人工生命优化算法对代表并联机器人位姿轨迹的高阶参数化空间曲线的参数进行优选,通过优化轨迹直纹曲面面积及其变化率和机器人的灵巧度,使并联机器人具有良好的运动学和动力学性能.最后以一三自由度球面并联机器人轨迹规划实例,验证所提出方法的可行性.     

机器人钣金折弯路径规划与仿真研究

针对钣金折弯机器人示教编程过程烦琐、效率低的问题,提出一种基于 Coin3D 的折弯机器人运动仿真系统方案。基于 Coin3D 虚拟场景技术,为折弯单元各组件建模,完成折弯单元加工环境的参数化配置和导入,实现仿真环境构建。为适应钣金工件随折弯加工逐步变形的特点,设计了对应的双向链式数据模型;分析了折弯机器人典型操作任务目标位姿的确定方法,并在此基础上参考人工示教经验,提出折弯机器人路径规划方法,实现了折弯机器人折弯加工的运动仿真。仿真实验验证了仿真系统和相关模型与方法的正确性,为折弯机器人离线编程系统研发奠定了基础。     

弧焊机器人焊炬姿态规划系统的研究

为提高弧焊机器人的适应性和自动规划功能，研究了一种空间全位置焊接条件下的焊炬姿态自动规划系统。该系统借助于相应的摄像机标定软件，计算测试软件和焊炬姿态规划软件，协调计算机视觉，信号采集，图像处理等模块检测焊缝的空间信息，然4后查询焊炬姿态优化数据库，运行离线偏程等离子模块，实现自动规划弧焊机器人的焊炬姿态，采用研制的爆炬姿态规划系统在空间全位置条件下进行焊接实验，结果表明，该系统能保证爆接中焊缝的成形良好。     

机器人离线编程系统运动误差分析

在ADAMS平台上对HP6机器人进行虚拟环境下的运动仿真,并通过Matlab建立机器人所识别的脉冲数据与各关节转角数据的关系.通过对ADAMS平台下虚拟机器人与真实机器人的运动精度进行误差分析与补偿,开展对转换误差的定性与定量研究,为优化离线编程系统转换精度提供一定的依据.     

Off-line programming of an industrial robot for manufacturing

A procedure for the automatic generation of the robot programming used in manufacturing operations is introduced in the present paper. The off-line programming system developed here includes graphical simulation of the robot and its workcell, kinematic model of the robot, motion planning and creation of the NC code for manufacturing process. The proposed system is applied in a robot with five revolute joints for manufacturing operations and in a robot with six revolute joints for welding operations.     

基于VRML-JAVA的机器人运动仿真研究

随着微机性能的提高 ,虚拟现实仿真已能在微机上进行。本文对运用VRML JAVA技术在微机上进行机器人运动仿真进行了研究 ,提出了运用CAD软件造型来构造虚拟环境 ,然后用JAVA EAI接口控制虚拟机器人运动的方法 ,在此基础上对S70 0工业机器人进行了建模和运动仿真。结果表明在微机上实现一个跨平台、网络化的仿真平台是完全可行的 ,这样的系统将可应用于机器人离线规划和编程及可视化教学等领域。     

基于量子粒子群优化算法的空间机器人非完整笛卡尔路径规划

利用自由漂浮空间机器人系统的非完整冗余特性,提出一种可使基座姿态和机械臂末端位姿同时到达期望状态的路径规划方法.该方法首先通过正弦多项式函数对机械臂关节角轨迹进行参数化,并根据基座姿态和机械臂末端位姿控制精度指标设计目标函数,由此,将自由漂浮空间机器人系统的非完整笛卡尔路径规划问题转换为非线性系统的优化问题.采用量子粒子群优化算法对非线性优化问题进行求解,将求解出的参数代入机械臂关节轨迹函数,即实现了非完整路径规划的目标.建立由飞行基座和6-DOF机械臂组成的空间机器人系统动力学模型,对所提出的方法进行仿真验证.试验结果表明,所提出的方法能够收敛于全局最优值,收敛速度快,所需调整参数少,且规划的关节路径满足关节角、角速度及角加速度的范围,关节路径平滑,适合于机械臂的控制.     

焊缝位姿及焊枪位姿的模型

针对机器人弧焊条件下的特殊要求,建立了焊缝位姿和焊枪位姿模型,以坐标系的形式定量描述焊缝及焊枪的位置和方向,确定了能够准确且严格地描述焊缝的焊接位置和焊枪姿态的参数：焊缝倾角、焊缝转角及焊枪工作角和行走角,并给出了计算方法。上述参数不但计算简便,而且可以直接代表焊接位置和焊枪姿态对焊接质量的影响因素。模型对于焊接工艺的建模与仿真以及机器人焊接的建模与离线编程具有非常重要的意义。     

Quadratic programming-based approach for autonomous vehicle path planning in space

Path planning for space vehicles is still a challenging problem although considerable progress has been made over the past decades.The major difficulties are that most of existing methods only adapt to static environment instead of dynamic one,and also can not solve the inherent constraints arising from the robot body and the exterior environment.To address these difficulties,this research aims to provide a feasible trajectory based on quadratic programming(QP) for path planning in three-dimensional space where an autonomous vehicle is requested to pursue a target while avoiding static or dynamic obstacles.First,the objective function is derived from the pursuit task which is defined in terms of the relative distance to the target,as well as the angle between the velocity and the position in the relative velocity coordinates(RVCs).The optimization is in quadratic polynomial form according to QP formulation.Then,the avoidance task is modeled with linear constraints in RVCs.Some other constraints,such as kinematics,dynamics,and sensor range,are included.Last,simulations with typical multiple obstacles are carried out,including in static and dynamic environments and one of human-in-the-loop.The results indicate that the optimal trajectories of the autonomous robot in three-dimensional space satisfy the required performances.Therefore,the QP model proposed in this paper not only adapts to dynamic environment with uncertainty,but also can satisfy all kinds of constraints,and it provides an efficient approach to solve the problems of path planning in three-dimensional space.     

座舱盖打磨下料机器人离线编程仿真

尝试通过机器人离线编程技术来解决座舱盖复杂曲面机器人打磨下料轨迹难以获取的难题,重点介绍了利用Tecnomatix PS辅助机器人离线编程的方法。首先运用SolidWorks三维建模技术建立机器人工况模型以模拟打磨机器人的工作环境,同时结合Tecnomatix PS的虚拟仿真技术实现了打磨机器人的离线编程和仿真,最终得到离线程序。基于Tecnomatix PS的编程作为整体离线编程方法的一部分,通过验证,其输出结果能够满足后续编程步骤的需求。     

机器人离线编程语言HRL及其开发环境

介绍机器人离线编程语言HRL及其开发环境。作为机器人离线编程与仿真系统HOLPSS的主要子系统，HRL实现了对一般4～6自由度机器人的离线编程，形成了基于微机的通用机器人语言。HRL语言系统结合HOLPSS的图形仿真系统，构成完善的离线编程与仿真环境，避免了文本编程与图形编程的弊端。论述HRL语言的数据类型及其操作、控制结构、轨迹规划、示教集成和通用性问题，并给出对PUMA560机器人的编程及结果仿真，仿真结果表明HRL语言系统是机器人程序快速生成的有力工具。     

一种双足机器人步态规划和运动仿真的研究

通过对人类行走步态的研究,结合双足机器人实际结构,规划机器人行走时的基本姿态及重心轨迹,建立运动学模型,根据规划的行走姿态及轨迹建立运动学方程。应用三维建模软件UG建立双足机器人的简化模型,导入仿真软件ADAMS中生成虚拟样机模型,并通过在Matlab中得到机器人行走的关节运动轨迹对虚拟样机模型进行控制,经仿真后,利用该虚拟样机模型对机器人行走步态进行运动学及动力学分析。应用虚拟样机方法,验证了步态规划的有效性。     

NOVEL APPROACH FOR ROBOT PATH PLANNING BASED ON NUMERICAL ARTIFICIAL POTENTIAL FIELD AND GENETIC ALGORITHM

A novel approach for collision-free path planning of a multiple degree-of-freedom (DOF) articulated robot in a complex environment is proposed. Firstly, based on visual neighbor point (VNP), a numerical artificial potential field is constructed in Cartesian space, which provides the heuristic information, effective distance to the goal and the motion direction for the motion of the robot joints. Secondly, a genetic algorithm, combined with the heuristic rules, is used in joint space to determine a series of contiguous configurations piecewise from initial configuration until the goal configuration is attained. A simulation shows that the method can not only handle issues on path planning of the articulated robots in environment with complex obstacles, but also improve the efficiency and quality of path planning.     

FMC中工业机器人程序快速规划系统的开发

以广东工业大学ＦＭＣ中心的柔性制造单元为基础,介绍了ＦＭＣ环境下工业机器人离线编程快速规划系统的开发过程。该系统应用后,机器人运行规划和编程速度大大加快,ＦＭＣ的安全性和运行效率得到提高。     

Optimal trajectory planning with application to industrial robots

A procedure is presented for planning optimal trajectories for application to industrial robots. First, trajectories are optimised by considering the nominal dynamics of a robot with rigid links and joints and with constraints on joint torque and speed. The minimum-time optimisation criterion is complemented by a miminal dynamic energy criterion that leads to smoother actuator inputs that do not excite joint vibrations. Weighting factors for these cost functions are then determined by trial simulations. By these means the effect of controller characteristics and elasticity, friction and backlash in the joints may be taken into account. A minimum-time movement for the real-world robot is obtained which displays the dynamical behaviour predicted in the planning procedure. Results from measurements and simulations for a PUMA 562 robot illustrate the approach. Further improvements may be achieved by a custom controller with the feedforward torques as shown in a comparison of trajectories executed with a VAL2 controller and a custom controller.     

一种六自由度工业机器人运动学分析及三维可视化仿真

针对Motoman-HP20机器人的构型特点,采用D-H坐标变换法建立其运动学坐标系,将机器人分解为位置结构和姿态结构,得到以位置矢量和欧拉角表示的完备广义坐标,利用位姿分离法对机器人进行逆运动学求解,求得各个关键转角。构建了三维可视化仿真环境,验证所提出的运动学算法的正确性。该仿真环境可以直观地观察机器人各部分的运动情况。     

桥梁检测机器人作业规划与位姿优化方法研究

针对桥梁底部病害人工检测的作业难题,介绍了桥梁检测机器人的工作原理,结合桥梁的结构化特征和视觉检测拍摄参数约束,研究了桥梁检测机器人作业规划与位姿优化方法。首先,提出一种以最佳拍摄模型约束的桥梁检测机器人拍摄作业位姿规划方法。在最佳拍摄规划方法的基础上,针对小箱梁桥梁和T型梁桥梁底部的褶皱结构,研究了以安全拍摄模型为约束的拍摄位姿优化方法,设计了结合拍摄偏角和拍摄距离的权重函数,推导了优化算法公式并给出了收敛证明。通过对不同拍摄参数的配置,进行了针对空心板桥梁的拍摄作业位姿规划方法仿真;针对小箱梁桥梁的结构,在位姿规划仿真结果基础上进行了位姿优化方法的仿真。最后以研制的桥梁检测机器人为对象,进行了现场测试与验证,仿真和实验结果均表明,该规划和优化方法符合桥梁拍摄检测的要求,具有很好的鲁棒性和实时性。     

基于遗传模拟退火算法的弧焊机器人系统协调路径规划

深入地研究了弧焊机器人系统的协调路径规划。从全局的角度用5元组序列描述了焊接路径。设计了评价 焊接路径目标函数:焊接位置函数、焊缝成形质量函数、关节位置函数和运动平稳性函数。以线性加权法为求解 多目标规划的基本思想,把遗传模拟退火算法用于弧焊机器人与变位机协调路径规划,取得了很好的效果。协调 路径规划精确地保证焊缝的最佳焊接位置与最佳的焊枪姿态,并能找到柔顺的焊接路径,提高了机器人焊接的质 量和效率。     

工业机器人倍四元数轨迹规划算法的研究

针对工业机器人在笛卡尔空间的轨迹规划曲线的平滑性与实时性,提出一种用于描述超球面旋转的倍四元数对机器人运动轨迹进行球面线性插补,并结合正弦波加速度曲线升降速控制算法对轨迹规划的速度进行控制,为机器人的轨迹规划提供了一种新的位姿规划的解决方案。在六关节搬运机器人控制系统平台上进行了仿真与试验,验证了该算法解决方案的有效性。