Internet Control Architecture for Internet-Based Personal Robot

This paper proposes a novel direct internet control architecture for internet-based personal robot, which is insensitive to the inherent internet time delay. The personal robot can be controlled using a simulator provided at a local site. Since the internet time delay is affected by the number of nodes and the internet loads, it is variable and unpredictable so that a large internet delay makes some control inputs distorted. The proposed control architecture guarantees that the personal robot can avoid obstacles and reduce the path error and the time difference between a virtual robot at the local site and a real robot at the remote site. This architecture is extended for an uncertain environment. Simulations and experimental results in the real internet environment demonstrate the effectiveness and applicability of the proposed internet control architecture.     

Bilateral teleoperation through the Internet

This paper proposes a stable control structure for the bilateral teleoperation of robots through Internet. The problem is motivated by the increasing use of the Internet as a communication channel. Internet has a time-varying delay which depends on factors such as congestion, bandwidth and distance. In this work, we propose a control structure for the teleoperation of a manipulator robot with force feedback. Such a control structure includes state controllers (placed on the local and remote sites) and a time-delay compensation, which modifies the delayed position command generated by the human operator using the force that he feels in such a delayed moment and the current force between the slave and the remote environment. In addition, the proposed control scheme is designed considering a model of the communication channel. Finally, experiments of bilateral teleoperation of robots through Intranet and Internet are shown to test the performance and stability of the designed teleoperation system.     

一种基于用户意图建模的Internet移动机器人控制方法

Internet上数据传输存在的不确定性时延,使得遥操作的网络机器人无法及时完成远程操作者期望的动作．提出一种新的方法,即对用户意图进行建模,通过移动机器人的自主性来补偿不确定时延对系统性能造成的影响．在对用户操作机器人的意图建立模型后,利用贝叶斯技术对用户意图进行渐进推断,从而使得机器人能够识别用户赋予的任务,并自主地执行该任务,而无需与用户频繁交互．这大大减少了数据传输、提高了整个控制系统的效率．实验结果证明了所提方法的有效性和可行性．     

基于因特网的运动控制系统中变采样过程的研究

基于因特网的运动控制系统多采用时间驱动方式,由于采样周期与时延的不匹配,在报文接收端会出现空采样和多采样现象,这些采样现象使系统变得更难控制.提出事件-时间驱动方式,即采样周期要随着网络环境的变化而变化.不但对该驱动方式下的采样信息处理方法进行研究,而且提出了相应的网络时延补偿方案.理论分析和实验结果证明该方法可在任何因特网环境下实现运动控制的任务.     

遥操作机器人系统的变时延控制

由于遥操作机器人传输通道中存在着变化的通讯时延,造成了系统不稳定和操作性能降低等问题。为了消除或减少时延的影响,在利用RBF神经网络进行延时预测的基础上,通过改进型Smith预估器进行遥操作机器人的时延控制,从而使系统稳定,并易于操作。理论分析表明,该方案对时延的变化有较强的适应性,控制系统的鲁棒稳定性和动态品质均优于单纯的Smith预估补偿控制,且易于实现。仿真结果表明,在时延情况下,该方法可实现对遥操作机器人较为准确的测控。     

Real-time compliance control of an assistive joint using QNX operating system

An assistive robot is a novel service robot, playing an important role in the society. For instance, it can amplify human power not only for the elderly and disabled to recover/rehabilitate their lost/impaired musculoskeletal functions but also for healthy people to perform tasks requiring large forces. Consequently, it is required to consider both accurate position control and human safety, which is the compliance. This paper deals with the robot control compliance problem based on the QNX real-time operating system. Firstly, the mechanical structure of a compliant joint on the assistive robot is designed using Solidworks. Then the parameters of the assistive robot system are identified. The software of robot control includes data acquisition and processing, and control to meet the compliance requirement of the joint control. Finally, a Hogan impedance control experiment is carried out. The experimental results prove the effectiveness of the method proposed.     

基于P2P的移动机器人远程控制系统

将机器人远程控制技术与Internet相结合,引入NAT穿越技术,设计一种基于P2P结构的机器人远程控制方案,并在模拟广域网环境下,搭建P2P移动机器人远程控制系统平台。系统实现对移动机器人的远程P2P控制,将移动机器人反馈的视频数据加以显示,有效利用有限的带宽资源,扩大远程控制端对机器人的控制范围。运行及时延测试结果表明,该系统具有较好的通用性与实时性。     

利用事件和期限驱动对机器人延时的优化

随着科技的进步,机器人领域得到了飞速发展,为了更好地让机器人适应复杂工作环境,需要进一步提高机器人的感知性能。大多数机器人采用视觉作为感知手段。但由于图像中包含大量数据以及处理这些数据需要花费大量时间,导致了机器人有显著的延时,从而导致机器人性能的下降。因此,为了解决这一问题,提出了一种基于期限驱动和事件驱动控制方法,该方法的核心是把基于模型的控制设计方法的思想应用到基于视觉的自定位算法的机器人运动控制中。同时考虑了一种简单的基于随机样本一致性的定位算法的延时情况。实验结果证明,提出的期限驱动和事件驱动控制设计明显优于传统的周期控制。     

Teleoperation Control of a Position‐Based Impedance Force Controlled Mobile Robot by Neural Network Learning: Experimental Studies

Effective haptic performance in teleoperation control systems can be achieved by solving two major problems: the time‐delay in communication channels and the transparency of force control. The time‐delay in communication channels causes poor performance and even instability in a system. The transparency of force feedback is important for an operator to improve the performance of a given task. This article suggests a possible solution for these two problems through the implementation of a teleoperation control system between the master haptic device and the slave mobile robot. Regulation of the contact force in the slave mobile robot is achieved by introducing a position‐based impedance force control scheme in the slave robot. The time‐delay problem is addressed by forming a Smith predictor configuration in the teleoperation control environment. The configuration of the Smith predictor structure takes the time‐delay term out of the characteristic equation in order to make the system stable when the system model is given a priori. Since the Smith predictor is formulated from exact linear modeling, a neural network is employed to identify and model the slave robot system as a nonlinear model estimator. Simulation studies of several control schemes are performed. Experimental studies are conducted to verify the performance of the proposed control scheme by regulating the contact force of a mobile robot through the master haptic device.     

Design and Analysis of Internet-Based Tele-Coordinated Multi-Robot Systems

The coordination of multi-robots is required in many scenarios for efficiency and task completion. Combined with teleoperation capabilities, coordinating robots provide a powerful tool. Add to this the Internet and now it is possible for multi-experts at multi-remote sites to control multi-robots in a coordinated fashion. For this to be feasible there are several hurdles to be crossed including Internet type delays, uncertainties in the environment and uncertainties in the object manipulated. In addition, there is a need to measure and control the quality of tele-coordination. To this end, the measure of force sensed by each robot is suggested and justified as a coordination index. It was proven that if n robots are event-transparent and event-synchronous then they can be teleoperated under random delay conditions to coordinate to any index value, which is feasible under no delay conditions. The design procedure that ensures a system can satisfy a small coordination index was presented and analyzed.In addition, the design and analysis of event-synchronous systems using Petri Nets is detailed. The Petri Net design methodology is presented for both event-synchronous single operator single robot teleoperation systems and event-synchronous multi-operator multi-robot teleoperation systems.The theory developed was tested by bilaterally tele-coordinating two mobile manipulators via the Internet. The experimental results confirmed the theoretical results presented.     

无源散射变换的双边移动机器人网络遥操作

网络遥操作系统的随机时延给控制器设计带来巨大挑战,严重时破坏系统的稳定性。首先对遥操作无源理论及其波变量控制方法做了简单综述,然后提出直接无源散射变换方法,它将无源双边控制方法推广到具有随机时延的网络遥操作系统中去,保证网络遥操作系统在任何不对称随机网络时延情况下稳定。最后基于此变换方法设计了一个虚拟主从手双边移动机器人网络遥操作方案,并进行了仿真验证,结果表明结出的设计方法能满足系统性能要求。     

A learning particle swarm optimization algorithm for odor source localization

This paper is concerned with the problem of odor source localization using multi-robot system. A learning particle swarm optimization algorithm, which can coordinate a multi-robot system to locate the odor source, is proposed. First, in order to develop the proposed algorithm, a source probability map for a robot is built and updated by using concentration magnitude information, wind information, and swarm information. Based on the source probability map, the new position of the robot can be generated. Second, a distributed coordination architecture, by which the proposed algorithm can run on the multi-robot system, is designed. Specifically, the proposed algorithm is used on the group level to generate a new position for the robot. A consensus algorithm is then adopted on the robot level in order to control the robot to move from the current position to the new position. Finally, the effectiveness of the proposed algorithm is illustrated for the odor source localization problem.     

预估控制下的实时网络遥操作移动机器人

构建了能使操作者通过Internet远程实时控制的移动机器人系统．为了补偿网络时延和抵消其对遥操作系统的影响,基于我们以前提出的改进型Smith预估器原理,采用了预估控制策略．为了保证系统稳定性和透明性,基于主从端的传感器信息交换,设计了一个动态模型管理器,其中模型和力反馈误差调节通过模糊控制实现．除了力反馈外,为了增强遥操作的实时性,引入了预估的虚拟显示．为了精确地预测网络时延,提出了一个新颖的时钟同步算法．为了降低时延抖动,结合我们提出的两个算法,实现了数据缓冲策略．最后,通过长距离的网络遥操作实验验证了系统和控制策略的实用性和有效性．     

PMSM驱动机器人的FSMC与EPCH协同控制

单独一种控制方法难以使机器人末端快速、准确地跟踪位置变化,针对这一问题,提出了模糊滑模(FSMC)信号控制与误差端口受控哈密顿(EPCH)能量控制的协同控制策略.FSMC解决了系统动态时的快速性问题,EPCH控制解决了系统稳态时的准确性问题.设计了基于误差的协同函数,利用协同函数来实现对机器人关节系统的协同控制,使机器...     

连续型同心管机器人正运动学快速求解方法

针对可在受限环境中灵活运动的连续型同心管机器人传统正运动学方法计算时间较长,不利于机器人实时运行的问题,本文提出了基于机器人几何学的同心管机器人正运动学快速求解方法,能够在精度损失有限的情况下,提高正运动学模型的计算效率.先根据Cosserat杆模型对同心管机器人进行建模,再利用李代数理论建立了机器人空间位置和曲率的关系式,并结合提出的正运动学方法,对机器人进行了基于逆运动学的开环控制实验.最后通过3管机器人的仿真和实物实验验证了本文所提方法的快速性和有效性.     

Distributed Control of Nonholonomic Robots Without Global Position Measurements Subject to Unknown Slippage Constraints

This paper studies the fully distributed formation control problem of multi-robot systems without global position measurements subject to unknown longitudinal slippage constraints.It is difficult for robots to obtain accurate and stable global position information in many cases,such as when indoors,tunnels and any other environments where GPS(global positioning system)is denied,thus it is meaningful to overcome the dependence on global position information.Additionally,unknown slippage,which is hard to avoid for wheeled robots due to the existence of ice,sand,or muddy roads,can not only affect the control performance of wheeled robot,but also limits the application scene of wheeled mobile robots.To solve both problems,a fully distributed finite time state observer which does not require any global position information is proposed,such that each follower robot can estimate the leader’s states within finite time.The distributed adaptive controllers are further designed for each follower robot such that the desired formation can be achieved while overcoming the effect of unknown slippage.Finally,the effectiveness of the proposed observer and control laws are verified by simulation results.     

网络延时和负荷变化对基于网络的遥操作机器人系统的影响和解决方法

在基于网络的遥操作机器人系统中,由于网络延时具有随机性、可变性和不可预测性,这将会影响遥操作的实时性、准确性和可靠性。文章提出了一种网络延时模型,分析了网络延时和命令数据包丢失对基于网络的机器人遥操作系统所造成的影响,以及由于网络信道负荷的动态变化和延时抖动对视频传输所造成的不连续性和抖动现象,并提出了相应的解决办法。通过基于网络的机器人遥操作实验证明了该文所提出方法的有效性和可行性。     

并联机器人分离干扰器的离散变结构控制研究

本文针对一种以步进电机驱动的少自由度并联机器人,采用带分离干扰补偿器的离散变结构控制器。仿真结果表明该算法解决了传统变结构控制在数字实现时的抖振问题,且系统抗干扰能力强,对系统参数变化不敏感,具有良好的跟踪性能,实现了对该并联机器人机构的高精度实时控制。     

Teleoperation of Mobile Robots With Time-Varying Delay

This paper proposes a stable control scheme for teleoperation of mobile robots with visual feedback in presence of time-varying delay. The proposed control scheme is based on using a model of the human operator to combine (on the remote site) the velocity command generated by the human operator in a delayed time instant, the received information (which stimulates the operator) in such moment, and the current state of the remote site to set the velocity reference, which is applied to the mobile robot. In addition, the proposed control scheme does not modify the information sent from the remote site to the local site. On the other hand, the proposed scheme uses estimated parameters of the human operator and a fictitious force, which is calculated using data fusion from ultrasonic sensors and optical flow field taken from panoramic images. To illustrate the performance and stability of the proposed control structure, several teleoperation experiments between Argentina and Brazil linked via Internet are shown.     

On the position analysis of a new spherical parallel robot with orientation applications

In this paper, we propose a new spherical parallel robot for celestial orientation, and rehabilitation applications (TV satellite dish, tracking systems, solar panels, cameras, telescopes, table of the machine tools, ankle, shoulder, wrist and etc.). The proposed robot can completely rotate about an axis. After describing the robot and its inverse position analysis, using the genetic algorithm, the dimensional optimization to maximize the workspace of the robot is performed. The workspace analysis shows that the proposed robot has a relatively large workspace. Also, singularity analysis represents that the manipulator is a singularity-free workspace. It is a great advantage of the proposed robot. Next, an optimal approach is proposed for solving the direct position problem of the robot. According to the geometry of the robot, two coupled trigonometric equations are obtained through using a special form of Rodrigues' rotation formula. Next, the two coupled equations are transformed to a 8-degrees polynomial using the Sylvester's Dialytic elimination method. Finally, a numerical example for the robot with an asymmetric structure is given with eight real solutions. Therefore, the polynomial being minimal and the proposed approach is optimal. This greatly decreases computational time, which is necessary for dynamics, control and simulation.