基于激光传感器的多移动机器人位姿测量系统

为机器人准确定位设计了一个基于激光传感器的移动机器人位姿测量系统。测量系统用激光传感器扫描区域内的以矩形为标识的机器人,将测量数据传输到计算机上,通过数据处理软件进行数据处理,提取属于机器人的特征,同时结合机器人前一时刻的位姿,实时计算机器人当前位姿。实验结果表明,此系统能迅速识别机器人,并准确地确定每个机器人位置和姿态,通过网络向机器人发送其位姿数据,实现多移动机器人的精确定位。     

Sonar based position estimation system for an autonomous mobile robot operating in an unknown environment

The paper presents a new method of position estimation for robot navigation in a completely unknown environment. The method is different from conventional ones in that it does not need any kind of a priori reference model or man-made landmarks. A series of local maps is built and updated from sonar data while the robot is exploring the unknown environment. Among the constructed local maps, the robot autonomously selects the ones with distinctive features and memorizes them as reference landmarks. An orientation clustering method is developed which enables the robot to extract the features of the map. The maps selected in such a way are then used to estimate the position and orientation of the robot while undertaking the given task. In doing so correspondence indices are defined to determine the corresponding reference map to the current local one among the numerous stored maps. The two maps are matched so as to minimize the discrepancy between them, thus enabling one to estimate the position and orientation of the robot. The usefulness of all these approaches is illustrated with the results produced by a real robot equipped with ultrasonic sensors.     

一种基于工具坐标系的机器人运动学参数标定方法

机器人末端执行器位姿误差在基础坐标系中表示时,误差模型中包含姿态误差与位置矢量的乘积项,影响了参数标定识别精度。以工具坐标系为参考系,给出一种基于指数积公式包含关节约束条件的机器人位姿误差标定模型,避免了姿态误差与位置矢量的乘积项对参数标定识别精度的影响。以UR5机器人为标定对象,采用LeciaAT960-MR激光跟踪仪为测量设备,进行参数标定试验。试验结果表明,经参数标定后UR5机器人位置误差模和姿态误差模的平均值分别减小了91.07%和89.16%。     

基于单目视觉的并联机器人末端位姿检测

高效、准确地检测机器人末端位姿误差是实现运动学标定的关键环节。提出一种基于单目摄像机拍摄立体靶标序列图像信息的末端执行器6维位姿误差辨识方法,构造具有平行四边形几何约束的四个空间特征点,并以平行四边形的两个消隐点为约束,建立空间刚体位姿与其二维图像映射关系模型,实现末端位姿的精确定位,然后以Delta高速并联机器人为对象,进行了运动学标定试验,验证该方法的有效性,为这类机器人低成本、快速、在线运动学标定提供重要的理论与技术基础。     

全天候移动车间巡检机器人目标定位算法

全天候移动车间巡检机器人移动轨迹复杂,为获取高精度的巡检机器人目标定位结果,提出一种全天候移动车间巡检机器人目标定位算法。优先标定得到移动车间环境的相机,获取相机参数,通过高低纹理匹配完成移动车间环境重建。然后通过相机内外参数将匹配点的图像坐标和世界坐标相关联,以此为依据估计巡检机器人的位姿。最终将得到的移动车间环境地图和周围数据相结合,采用粒子滤波算法对全天候移动车间巡检机器人位置组建的粒子群集合优化处理,通过不断迭代更新,输出目标定位结果。结果表明,所提算法可以有效降低巡检机器人目标定位时间以及联合定位误差,获取准确率更高的目标定位结果。     

基于两轮自平衡机器人组合定位方法的研究

对两轮自平衡机器人的运动控制过程中相对定位的问题进行了研究.根据两轮自平衡车的特点,对诸如车轮打滑、碰撞、越障及转向等运动情况下的位置传感器和姿态传感器的信号进行了分析,提出了将光电码盘、MEMS陀螺仪与MEMS加速度计数据融合的方法,对机器人的位姿进行检测估计,从而解决了采用传统的单一位置传感器对机器人测程不准确的问题.同时也降低了陀螺仪、加速度计固有漂移的不利影响,提高了两轮自平衡机器人的定位精度.通过对两轮机器人分别进行直线运动实验、越障实验和异常碰撞试验,验证了两轮自平衡机器人组合定位方法的合理性和有效性.     

一种球形移动机器人传感系统设计

文章为了解决球形机器人自主控制的问题,根据球形机器人结构和运动的特殊性,设计了一种球形机器人的传感系统。建立了无滑动条件下球形机器人运动模型,根据运动模型由惯性测量系统和光电码盘数据组合得到机器人位姿。利用激光测距传感器获取周围障碍物信息。通过全局CCD视觉传感器跟踪识别目标物体,使用手眼CCD视觉传感器和超声传感器定位目标物体并协调机械臂实现对操作目标准确快速的抓取、放置。     

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.     

Design of an absolute location and position measuring system for a mobile robot

This paper focuses on a development of a sensor system measuring locations of a vehicle to localize a mobile robot while it tracks on the track (location sensor). Also it focuses on a system configuration identifying the vehicle’s orientation and distance from the object while it is stationary at certain station (position sensor). As for the location sensor, it consists of a set of sensors with a combined guiding and counting sensor, and an address-coded sensor to localize the vehicle, while moving on the rail. For the position sensor a PSD (Position Sensitive Device) sensor with photo-switches sensor to measure the offset and orientation of the vehicle at each station is introduced. Both sensor systems are integrated with a microprocessor as a data relay to the main computer controlling the vehicle. The location sensor system is developed and its performance for a mobile robot is verified by experiments. The position measuring system is proposed and is robust to the environmental variation. Moreover, the two kinds of sensor systems guarantee a low cost application and high reliability.     

球形机器人轨迹跟踪算法

典型的动态轨迹跟踪算法针对非完整移动机器人提出了一种系统框架,并且在模拟实验中展现了良好的跟踪性能。然而,该算法在2自由度摆球形机器人系统中并未同时实现位置和姿态的收敛。讨论了一种实用的球形机器人轨迹跟踪控制算法．着眼于位置与姿态的同时收敛。受跟踪引导模式的启发．提出了一种适用于球形机器人轨迹跟踪控制的模糊自适应控制方案,并通过MATLAB对提出的轨迹跟踪方法进行了有效性验证。     

一种新型大中心孔绝对式磁编码器

为测量机器人关节端角度和电机端位置,研制一种基于霍尔原理的新型绝对式磁编码器,采用大中心孔结构,具有大的中心孔、体积小、结构紧凑、分辨率高、绝对式位置测量等特点。传感器由转子和定子组成,转子的磁码盘包括主码道和游标码道,定子由霍尔敏感芯片和信号调理电路板组成;根据游标计算原理,得到了传感器绝对角度的计算方法。通过仿真软件分析了转子的磁场分布和模态;为进一步提高磁编码器的输出精度,提出一种基于遗传优化算法的误差补偿模型,搭建了传感器的标定平台,实验结果表明传感器绝对定位精度可以达到0.2°,经过模型补偿后可以达到0.036°,满足机器人关节及伺服系统设计要求。     

室内自主式移动机器人定位方法研究

定位是确定机器人在其工作环境中所处位置的过程。本文对室内自主式移动机器人的定位技术进行了研究。论述了自主式移动机器人定位系统与地图构造中所面临的主要问题及其解决方法并指出了该领域今后的发展方向。     

移动机器人平台的运动学分析

通过D-H坐标变换法,建立单侧摇臂对移动机器人平台的运动学模型,然后根据矢量迭加的方法,综合考虑双侧摇臂作用对机器人平台位姿影响,建立了移动机器人平台位姿估计系统模型,为平台控制系统的设计提供了理论的依据.     

室内自主式移动机器人定位方法研究

定位是确定机器人在其工作环境中所处位置的过程.应用各种传感器感知信息实现可靠的定位是自主式移动机器人最基本、也是最重要的一项功能之一.本文对室内自主式移动机器人的定位技术进行了综述,介绍了当前自主式移动机器人定位方法的研究现状.同时,对国内外具有典型性的研究方法进行了较详细的介绍,并重点提出了几种室内自主式移动机器人通用的定位方法,对其中的地图构造、位姿估计方法进行了详细介绍.最后,论述了自主式移动机器人定位系统与地图构造中所面临的主要问题及其解决方法并指出了该领域今后的研究方向.     

A measuring method for large antenna assembly using laser and vision guiding technology

In this paper a new conception of a measuring method is proposed to assist precision automatic assembly of large radar antenna. Different from conventional 6-DOF tracking methods, the measuring system decomposes the measurement task into several independent steps. The measuring system consists of a camera, two laser distance meters, two position sensitive detectors (PSD) and an inclination angle sensor. The camera is adopted to guide antenna position and orientation adjustment over a large space. Laser meters and PSD sensor is used to precisely measure the position and orientation of radar antenna. To improve the practicability of measuring system, a robust vision measurement method is proposed. The mathematical models and practical calibration methods for measurement are elaborated. The preliminary experimental results agree with the methods currently being used for orientation and position measurement. The measuring method provides an alternative choice for the metrology in precision assembly. By using the method proposed in this paper, the measuring system can achieve a measurement accuracy of approximately 1 mm, which meets the accuracy requirement of large radar antenna automatic assembly application. Besides, the measuring method provides an alternative solution for large scale metrology which take the environmental impact into account.     

基于P3P原理的装配机器人手眼标定方法研究

针对一类微装配机器人的固定式手眼系统,提出了一种标定方法。采用P3P位姿测量原理获得空间点在摄像机坐标系中的坐标,从而建立机器人空间坐标系与手眼坐标系的位姿关系,给出了手眼系统标定的具体步骤,建立了标定方程组及其基于最小二乘法的求解方法。考虑到计算和测量误差等因素带来的旋转矩阵非单位正交矩阵的问题,采用了一种简单的校正算法进行修正。该方法无需复杂的辅助设备,标定过程简单,相关实验验证了该方法的标定精度和有效性。     

基于三点透视模型的线结构光系统标定方法

针对现有线结构光传感系统标定过程中对设备要求高、标定过程繁琐等问题,提出一种基于三点透视模型的快速标定方法。引入一个可自由移动的平面靶标,靶标上只需要共线、且相互位置确定的三个特征点,利用共线三点建立三点透视数学模型,根据三个特征点以及光条纹在摄像机像面的成像信息,就可以获取光平面上标定点在摄像机坐标系下的坐标。平面靶标在视觉范围内任意移动几个位置,得到光平面上多个标定点坐标,从而确定光平面方程。实验证明,该方法平均相对测量误差小于0.8%。该方法不需要昂贵的辅助调整设备,也不需要求解坐标系之间的转换矩阵,简单、快速,适合现场标定。     

基于微小型移动机器人的微操作系统

提出一种新颖的基于宏/微双重驱动微小型移动机器人的微操作系统.机器人在宏运动状态下为典型的轮式机器人,在微运动状态下为尺蠖运动机器人.将集成微夹持器的微操作器安装在机器人移动定位平台上用于实现微操作任务.为了自动导航机器人完成微操作任务,设计外部智能视觉系统.视觉系统分为全局视觉与显微视觉两个子部分,机器人在全局视觉的导航控制下以宏运动状态实现大范围的粗定位,并使机器人微夹持器末端准确地进入显微镜视场.在显微视觉的导航控制下以微运动状态实现小范围、高精度的精定位,并完成微操作任务.试验表明,提出的基于微小型移动机器人的微操作系统能够成功地实现微小零件的夹取与装配.     

New hybrid vision-based control approach for automated guided vehicles

Automated guided vehicles (AGVs) are a common choice made by many companies for material handling (MH) in manufacturing systems. AGV-based internal transport of raw materials, goods, and parts is becoming improved with advances in technology. Demands for fast, efficient, and reliable transport imply the usage of the flexible AGVs with onboard sensing and special kinds of algorithms needed for daily operations. So far, the majority of these transport solutions have not considered the modern techniques for visual servoing, monocular SLAM, and consequently, the usage of camera as onboard sensor for AGVs. In this research, a new hybrid control of AGV is proposed. The main control algorithm consists of two independent control loops: position-based control (PBC) for global navigation and image based visual seroving (IBVS) for fine motions needed for accurate steering towards loading/unloading point. By separating the initial transportation task into two parts (global navigation towards the goal pose near the loading/unloading point and fine motion from the goal pose to the loading/unloading point), the proposed hybrid control bypasses the need for artificial landmarks or accurate map of the environment. The state estimation of the robot pose is determined in terms of monocular SLAM, via extended Kalman filter coupled with feedforward neural network—the neural extended Kalman filter (NEKF). NEKF is used to model unknown disturbances and to improve the robot state transition model. The integration of the new hybrid control and NEKF has been tested in laboratory with the mobile robot and simple camera. Experimental results present the effectiveness of the proposed hybrid control approach.     

一种协作机器人位姿重复性优化综合

在给定位姿重复性要求的前提下,寻找各关节随机运动精度的最优分配方案能够使协作机器人设计更加合理,对降低机器人制造成本有重要意义。首先,在机器人位姿重复性分析的基础上,建立了位姿重复性数学模型,该数学模型包含机器人位置重复性和姿态重复性;其次,以协作机器人KUKA iiwa 7为例,以关节运动误差最大化为优化目标,对该机器人位姿重复性进行优化综合,获得各关节随机运动精度的最优分配方案;最后,对KUKA iiwa 7机器人进行位姿重复性实验,结果验证了该方法的正确性,基于该方法的精度设计结果能够使协作机器人设计更加合理。