一种并联机械手视觉引导算法

钣金冲压件为例,根据传送带输送的工件具有一致性的特点,介绍了用于从传送带上抓取并将其摆放整齐的并联机械手的视觉引导算法设计,采用一种非匹配的算法,快速将在传送带上杂散分布的工件的位置和角度计算出来;该算法较模板匹配法运算量大大减少,保证了系统的实时性;另外,对于传送带上工件正反面颠倒、工件重叠现象,算法也进行了相应处理;机械手可根据视觉算法得到的工件信息,逆解计算出机械手主动臂转角,从而实现拾放(pick-and-place)操作;对3万件工件实测,其中发生重叠的工件43个,没有正确识别工件28个;该算法对工件定位准确度达到99.7%,证明该算法具有很高的可靠性。     

Delta机器人传送带控制系统研究

本文针对制造业中人工分拣产品效率低下、错误率和成本较高的问题,将工业机器人应用于产品分拣。设计了Delta视觉机器人在工业生产中整体的控制流程,由视觉部分捕获传送带上的产品,经过一系列分析处理后移动机械手,实现对产品的抓取。为更准确抓取产品,重点提出了一种针对Delta视觉机器人传送带标定的方法。准备好两个标定物.然后按照下述步骤完成标定:第一步,使机械手末端与第一个标定物重合,第二步,移动传送带一段距离后使机械手重合同一点,第三步保持传送带不动移动机械手,使机械手与第二个标定物重合,从而完成标定。     

基于OpenCV的机器视觉尺寸测量研究

通过对激光测距传感器与机器视觉的研究利用激光测距传感器、视觉传感器相结合的方法,提出了一种不同于结构光和双目尺寸测量的更为简单有效的新方法和新技术。首先对灰度直方图比较分析选取了最佳滤波方法,然后通过激光测距传感器测距和单目视觉传感器进行边缘的精确检测。激光测距传感器实现了对采样目标车厢进行快速测距定位,计算出采样机械手与目标车辆的相对位置关系。视觉传感器准确识别车厢尺寸及定位,为煤炭采样机械手自动采样提供了实现基础。检测目标是拉煤货运火车车厢,给煤炭采样行业带来更为简单有效,准确的目标定位的识别系统和方法。     

机械手对目标物体抓取的研究

机械手在工业控制自动化中有着广泛的应用,介绍了一种主要由视觉和力觉传感器、电机及单片机和PC构成的四自由度机械手系统。主要讨论了该控制系统图象分析过程,系统硬件的结构和抓取控制的原理,并给出了上位机与下位机的串口通讯。试验结果表明该系统能够完成对形状为立方体的目标物体的抓取。     

PUMA760基于红外接近觉控制与编程实验系统

本文介绍 PUMA760 工业机器人基于红外接近觉传感器信号控制与编程实验系统。提出了搜索信号极值确定基准相对位置的方法,在位置控制系统中加入了基于传感器信号控制的指令,使 PUMA760完成了快速寻找、接近、定位和抓取非完全固定方位和高度的工件的动作.     

基于立体视觉的机械手未知平面内曲线跟踪

为了提高机械手应用的灵活性,增强机械手对动态环境的适应能力,降低机械手对工件位置的依赖性,采用立体视觉技术对未知平面的法线方向进行估计,根据工程应用中对末端执行器的速度以及位姿的实际要求,采用PID控制策略控制机械手末端执行器与工件之间的相对位姿.进行了仿真实验以验证所提方法的有效性,结果表明:该方法能够实现末端执行器和工件之间相对位姿的动态控制.     

混合摄像机视觉伺服机器人研究与应用

针对单目视觉机器人工件抓取与放置精度不高的问题,提出了基于位置的混合摄像机视觉伺服系统,采用Eye-in-hand和Eye-to-hand摄像机结合的模式,建立混合摄像机视觉机器人系统以实现工件的精确放置.Eye-in-hand摄像机实现对工件的定位和抓取,Eye-to-hand摄像机用于确定机械手爪中心轴线与工件中线的偏差,确保工件精确放置在期望位置.实验结果表明:该混合摄像机视觉伺服机器人系统能将工件准确放置在期望位置.     

四自由度折叠式机械手的控制系统

四自由度折叠式机械手是一台ＳＴＤ戒严控制机管理和控制，通过视觉图象和接近觉传感器操纵机械手在移动空间中完成联送机器人任务，文中推导了机械手运动学方程，给出了运动学正逆解，详细介绍了可编位置控制系统和操纵系统。     

人和机械手象棋对弈系统的研究与实现

综合运用计算机程序设计、数字图像处理技术及串口通讯技术实现了人和机械手的象棋对弈系统:人走后的棋子的位置信息由低成本普通摄像头实时传给计算机,以对位置信息进行图像处理判断出人的走步,上位机根据处理得到的结果再通过串口通讯技术给下位机PLC发相应的指令,使其来控制机械手下一步的下棋动作.将计算机视觉领域中的图像分析与图像识别技术应用于对机械手操作目标的监测与识别,适应了现代化的工业要求,具有良好的应用与发展前景.     

基于机器视觉技术的易拉罐罐底喷码检测系统设计

本文根据食品饮料行业易拉罐生产线的工作环境以及罐底喷码检测的检测要求,研制了基于康耐视机器视觉的易拉罐罐底喷码检测系统,实现对易拉罐喷码不合格的产品进行自动检测与快速剔除。该检测系统由光源与视觉处理系统、电气控制与人机交互系统、次品剔除装置等组成。当易拉罐通过成像系统时,金属接近开关触发光源频闪和工业智能相机,获得高速易拉罐罐底图像,智能相机对其分析处理,由电气控制系统执行检测结果,从而达到分拣不良品的目的。通过实际项目应用证明：该系统实时性好,可靠性高,有效地提高了在生产过程中产品喷码质量的控制。     

An adaptive observer for a spacecraft–manipulator system using a camera mounted on its spacecraft

This paper deals with a motion control system for a space robot with a manipulator. Many motion controllers require the positions of the robot body and the manipulator hand with respect to an inertial coordinate system. In order to measure them, a visual sensor using a camera is frequently used. However, there are two difficulties in measuring them by means of a camera. The first one is that a camera is mounted on the robot body, and hence it is difficult to directly measure the position of the robot body by means of it. The second one is that the sampling period of a vision system with a general-purpose camera is much longer than that of a general servo system. In this paper, we develop an adaptive state observer that overcomes the two difficulties. In order to investigate its performance, we design a motion control system that is constructed by combining the observer with a PD control input, and then conduct numerical simulations for the control system. Simulation results demonstrate the effectiveness of the proposed observer.     

Detection and prevention of slip using sensors with different properties embedded in elastic artificial skin on the basis of previous experience

In dexterous robotic manipulation, it is essential to control the force exerted by the robot hands while grasping. This paper describes a method by which robot hands can be controlled on the basis of previous experience of slippage of objects held by the hand. We developed an anthropomorphic human scale robot hand equipped with an elastic skin in which two types of sensor are randomly embedded. One of these sensors is a piezoelectric polyvinylidenefluoride (PVDF) film which can be used for the detection of pressure changes. The other is a strain gauge which can measure static pressure. In our system, PVDF films are used to detect slipping, and strain gauges to measure stresses which are caused by normal and shear forces. The stress measured by the strain gauges is used as input data to a neural network which controls the actuators of the robot. Once slip is detected, the neural network is updated to prevent it. We show that this system can control the grasp force of the robot hand and adapt it to the weight of the object. By using this method, it was shown that robots can hold objects safely.     

A human–robot interface for mobile manipulator

This paper presents a remote manipulation method for mobile manipulator through operator’s gesture. In particular, a track mobile robot is equipped with a 4-DOF robot arm to grasp objects. Operator uses one hand to control both the motion of mobile robot and the posture of robot arm via scheme of gesture polysemy method which is put forward in this paper. A sensor called leap motion (LM), which can obtain the position and posture data of hand, is employed in this system. Two filters were employed to estimate the position and posture of human hand so as to reduce the inherent noise of the sensor. Kalman filter was used to estimate the position, and particle filter was used to estimate the orientation. The advantage of the proposed method is that it is feasible to control a mobile manipulator through just one hand using a LM sensor. The effectiveness of the proposed human–robot interface was verified in laboratory with a series of experiments. And the results indicate that the proposed human–robot interface is able to track the movements of operator’s hand with high accuracy. It is found that the system can be employed by a non-professional operator for robot teleoperation.     

基于图像雅可比矩阵的智能机器人视觉跟踪

根据智能机器人视觉伺服的要求,建立了固定眼结构的MOTOMAN-SV3XL型工业机器人无标定视觉伺服系统.研究了目前在机器人视觉伺服研究领域中使用最为广泛的一类方法,即基于图像雅可比矩阵的方法.针对图像雅可比矩阵的特点,设计了一种基于简化Sage-Husa自适应滤波的图像雅可比矩阵在线估计算法,并将其应用于机器人视觉反馈控制任务中,实现了对二维平面上运动目标的跟踪,实验结果表明了该算法的有效性.     

Robotic execution of everyday tasks by means of external vision/force control

In this article, we present an integrated manipulation framework for a service robot, that allows to interact with articulated objects at home environments through the coupling of vision and force modalities. We consider a robot which is observing simultaneously his hand and the object to manipulate, by using an external camera (i.e. robot head). Task-oriented grasping algorithms (Proc of IEEE Int Conf on robotics and automation, pp 1794–1799, 2007) are used in order to plan a suitable grasp on the object according to the task to perform. A new vision/force coupling approach (Int Conf on advanced robotics, 2007), based on external control, is used in order to, first, guide the robot hand towards the grasp position and, second, perform the task taking into account external forces. The coupling between these two complementary sensor modalities provides the robot with robustness against uncertainties in models and positioning. A position-based visual servoing control law has been designed in order to continuously align the robot hand with respect to the object that is being manipulated, independently of camera position. This allows to freely move the camera while the task is being executed and makes this approach amenable to be integrated in current humanoid robots without the need of hand-eye calibration. Experimental results on a real robot interacting with different kind of doors are presented.     

应用神经网络改善足球机器人传感系统

为了解决足球机器人单一传感器所提供的定位数据的精度及稳定性不足以满足控制系统要求的问题,本文利用BP神经网络算法的学习功能,将目标足球及机器人自身状态信息作为标定数据,将视觉、加速度计、电子罗盘等多个传感器信息作为网络输入,以神经网络输出辅助足球机器人对目标足球的捕捉.实验仿真结果表明,神经网络算法提高了对目标足球的定位以及机器人自定位的精度,起到了预期的效果.滤波平均相对误差优于传统的卡尔曼滤波.     

A review on vision-based control of flexible manipulators

In this review, recent developments in the field of flexible robot arm control using visual servoing are reviewed. In comparison to rigid robots, the end-effector position of flexible links cannot be obtained precisely enough with respect to position control using kinematic information and joint variables. To solve the task here the use of a vision sensor (camera) system, visual servoing is proposed to realize the task of control flexible manipulators with improved quality requirements. The paper is organized as follows: the visual servoing architectures will be reviewed for rigid robots first. The advantages, disadvantages, and comparisons between different approaches of visual servoing are carried out. The using of visual servoing to control flexible robot is addressed next. Open problems such as state variables estimation as well as the combination of different sensor properties as well as some application-oriented points related to flexible robot are discussed in detail.     

Improved eye-vergence visual servoing system in longitudinal direction with RM-GA

Visual servoing is a control method to manipulate the motion of the robot using visual information, which aims to realize “working while watching.” However, the visual servoing towards moving target with hand–eye cameras fixed at hand is inevitably affected by hand dynamical oscillation. To overcome this defect of the hand–eye fixed camera system, an eye-vergence system has been put forward, where the pose of the cameras could be rotated to observe the target object. The visual servoing controllers of hand and eye-vergence are installed independently, so that it can observe the target object at the center of camera images through eye-vergence function. In this research, genetic algorithm (GA) is used as a pose tracking method, which is called “Real-Time Multi-step GA(RM-GA),” solves on-line optimization problems for 3D visual servoing. The performances of real-time object tracking using eye-vergence system and “RM-GA” method have been examined, and also the pose tracking accuracy has been verified.     

一种基于SSVEP的仿人机器人异步脑机接口控制系统

设计了稳态视觉诱发电位(SSVEP)空闲状态检测的特征提取方法,建立了基于SSVEP的异步脑机接口二级分类器结构,开发了基于TICC2430芯片的无线传感器网络模块,实现了机器人控制命令的远程传送,使该仿人机器人系统具有脑电控制、语音交互、游戏手柄交互、机器视觉与避障等功能.通过SSVEP窄闲状态检测实验验证了脑机接口...