自由飞行空间机器人的遥操作分数阶PID控制

作为空间操控的重要手段, 空间遥操作将趋向于更精细和更灵活. 然而传统的空间遥操作控制方法难以兼 顾操作的精细性和灵活性. 针对这一问题, 本文阐述了一种面向自由飞行空间机器人的遥操作分数阶PID控制方法. 首先根据自由飞行空间机器人的动力学模型, 设计了空间遥操作分数阶PID控制系统. 其次, 针对空间遥操作时滞 系统和系统的鲁棒性和抗干扰性要求, 基于系统的参数稳定域, 对分数阶PID控制器的参数进行整定. 最后, 数值仿 真和地面遥操作实验验证了分数阶PID控制器的跟踪性能、抗干扰性、鲁棒性和抗时延抖动性能. 因此, 本文设计的 分数阶PID控制器不仅适合于空间遥操作复杂时滞系统, 而且可以满足未来空间遥操作任务的发展需求.     

空间机器人遥操作预测仿真系统研究

针对通讯信号在天地传输过程中产生的较大时延导致对空间机器人的遥操作产生巨大困难,提出了通过虚拟现实技术对遥操作结果进行预测仿真.以规避传输时延影响的方法,并通过虚拟夹具技术降低操作复杂度;通过基于时间戳的修正策略以确保预测结果的准确性;针对具体任务环境提出了九点碰撞检测算法以提高系统运行效率.进行了多次与实物相结合的实验,实验结果表明,该系统运行快速、预测准确,可以有效地规避大时延天地传输带来的弊端,帮助地面操作员完成空间机器人的遥操作.     

面向双操作者的六足机器人共享遥操作

随着六足机器人遥操作系统研究工作的日趋深入,针对其操控系统的开发也将面临诸多挑战.为了实现双人操控条件下各操作者的控制权重实时分配,设计一种基于透明性及控制状态(TCS)的六足机器人双用户控制权重分配方法.其双主端与单从端采取位置-速度的交互模式,通过分析系统实时透明性与当前控制状态,构建三边遥操作控制律,实时计算共享因子,采用速度跟踪模式设计基于触觉力反馈的系统控制架构,并利用三端口绝对稳定定理确定控制律参数的稳定范围.最后,搭建半物理仿真实验平台并验证所设计的三边共享遥操作方法能够在兼顾系统安全性与透明性的同时以较高的效率与安全性实现六足机器人的双用户操控,并能充分考虑双用户的控制意图.     

Upper-body haptic system for snake robot teleoperation in pipelines

Snake robots have shown a great potential for operations in confined workplaces that are less accessible or dangerous to human workers, such as the in-pipe inspection. However, the snake robot teleoperation remains a nontrivial task due to the unique locomotion mechanism (e.g., helical motion) and the constraints of the workplaces including the low visibility and indistinguishable features. Most snake robot feedback systems are based on the live camera view only. It is hard for the human operator to develop a correct spatial understanding of the remote workplace, leading to problems such as disorientation and motion sickness in snake robot teleoperation. This study designs and evaluates an innovative haptic assistant system for snake robot teleoperation in the in-pipe inspection. An upper-body haptic suit with 40 vibrators on both the front and back sides of the human operator was developed to generate haptic feedback corresponding to the bottom and up sides of the snake robot, transferring the egocentric sensation of the snake robot to the human operator. A human-subject experiment (n = 31) was performed to evaluate the efficacy of the developed system. The results indicate that the proposed haptic assistant system outperformed other feedback systems in terms of both task performance and subjective workload and motion sickness evaluations. It inspires new control and feedback designs for the future snake robot in industrial operations.     

Controlling a robot manipulator with fuzzy voice commands using a probabilistic neural network

Natural language commands are generated by intelligent human beings. As a result, they contain a lot of information. Therefore, if it is possible to learn from such commands and reuse that knowledge, it will be a very efficient process. In this paper, learning from such information rich voice commands for controlling a robot is studied. First, new concepts of fuzzy coach-player system and sub-coach are proposed for controlling robots with natural language commands. Then, the characteristics of the subjective human decision making process are discussed and a Probabilistic Neural Network (PNN) based learning method is proposed to learn from such commands and to reuse the acquired knowledge. Finally, the proposed concept is demonstrated and confirmed with experiments conducted using a PA-10 redundant manipulator.     

基于ABB机器人的遥操作控制系统设计

工业机器人传统的编程与控制方式受距离空间限制,不便对机器人进行远程控制、控制不灵活。针对工业机器人的远程控制进行了研究,设计了基于ABB工业机器人的遥操作控制系统。在本地上位机上设计操作者界面,实现本地和远程程序的变量同步,以TCP/IP协议与ABB机器人控制柜通信,直接通过以太网对远程端的机器人进行控制和管理。在仿真和实验中,通过分析机器人对上位机给定轨迹的跟踪效果验证了系统的有效性。仿真和实验结果表明该系统能对远程ABB机器人进行有效的控制,可以让机器人代替人在恶劣的工作环境中作业,并提高工业生产效率。     

使用补偿策略的机器人遥操作系统的控制研究

利用混杂动态系统的思想通过同时采用事件和时间驱动的执行器方案来弥补机器人遥操作系统中的不确定时延现象.即作为控制节点的操作者的控制决策发出时间是事件驱动的(满足一定条件下),执行器节点的接收也是事件驱动的,但是执行则是时间驱动的.通过这样的方法确保网络遥操作系统在每一采样周期内都能得到新的控制信号,从而补偿网络延迟.     

Utility of stereoscopic displays for indirect-vision driving and robot teleoperation

The effectiveness of an active shutter-glasses stereoscopic display (SD) and a passive polarised SD was evaluated in a live robot-teleoperation task and a simulated indirect-vision driving task in various terrains. Overall, participants completed their tasks significantly faster with the SDs in three-dimensional (3D) mode than with the SDs in the baseline 2D mode. They also navigated more accurately with the SDs in 3D mode. When the effectiveness of the two types of SDs was examined separately, results showed that the active shutter-glasses SD resulted in faster responses and task completion times than the passive polarised SD, though most of the differences failed to reach statistical significance. Perceived workload when interacting with the two SD systems did not differ significantly between the active versus passive display types or between the 3D and 2D modes of operation; however, participants reported more severe discomfort after interacting with the passive polarised SD.     

医用机器人视频传输与遥操作控制研究

本文主要研究了一种新颖的半自主医用服务机器人,并着重阐述了其视频传输系统和遥操作控制系统的实现.其中视频传输系统采用MJPEG视频编码器对视频进行编解码,实现了对机器人现场视频的实时采集、编码、传输和播放;遥操作控制系统则利用操纵杆实现对机器人的无线实时控制.实验验证了视频传输系统和遥操作控制系统的可行性和有效性.     

A user study of command strategies for mobile robot teleoperation

This article presents a user study of mobile robot teleoperation. Performance of speed, position and combined command strategies in combination with text, visual and haptic feedback information were evaluated by experiments. Two experimental tasks were designed as follows: positioning of mobile robot and navigation in complex environment. Time for task completion and motion accuracy were measured and compared for different command strategies and types of feedback. Role of haptic, text and visual feedback information in combination with described command strategies is outlined.     

Approximate solutions to a parameterized sixth order boundary value problem

In this paper, the homotopy analysis method (HAM) is applied to solve a parameterized sixth order boundary value problem which, for large parameter values, cannot be solved by other analytical methods for finding approximate series solutions. Convergent series solutions are obtained, no matter how large the value of the parameter is.     

Haptic teleoperation of a multirotor aerial robot using path planning with human intention estimation

Classical haptic teleoperation systems heavily rely on operators’ intelligence and efforts in aerial robot navigation tasks, thereby posing significantly users’ workloads. In this paper, a novel shared control scheme is presented facilitating a multirotor aerial robot haptic teleoperation system that exhibits autonomous navigation capability. A hidden Markov model filter is proposed to identify the intention state of operator based on human inputs from haptic master device, which is subsequently adopted to derive goal position for a heuristic sampling based local path planner. The human inputs are considered as commanded velocity for a trajectory servo controller to drive the robot along the planned path. In addition, vehicle velocity is perceived by the user via haptic feedback on master device to enhance situation awareness and navigation safety of the user. An experimental study was conducted in a simulated and a physical environment, and the results verify the effectiveness of the novel scheme in safe navigation of aerial robots. A user study was carried out between a classical haptic teleoperation system and the proposed approach in the identical simulated complex environment. The flight data and task load index (TLX) are acquired and analyzed. Compared with the conventional haptic teleoperation scheme, the proposed scheme exhibits superior performance in safe and fast navigation of the multirotor vehicle, and is also of low task and cognitive loads.

     

基于时域无源性控制的六足机器人双边触觉遥操作

随着六足机器人研究工作的深入,针对其遥操作系统的开发面临诸多挑战.为了弥补松软接触条件对系统可控性及稳定性的影响,提出一种基于时域无源性控制(time-domain passivity control,TDPC)的六足机器人双边触觉遥操作方法.其主从两端采取位置-速度的交互模式,通过分析足-地柔性接触的作用机理,构建无源观测器和无源控制律以补偿足底滑移所导致环境系统的潜在有源性,采用速度跟踪模式设计基于触觉力反馈的系统控制架构,并利用Llewellyn准则确定控制律参数的稳定范围.最后,搭建半物理仿真实验平台并验证所提出的双边触觉遥操作方法在松软地形条件下能够保证六足机器人遥操作系统的稳定,且兼具较好的持续跟踪能力.     

基于OpenCV的遥操作工程机器人双目视觉定位技术

针对当前遥操作工程机器人双目视觉定位技术匹配精准度低,导致定位误差过大的问题,提出种基于OpenCV改进的遥操作工程机器人双目视觉定位技术。在分析HSV色彩空间后,建立适合工程机器人的颜色特征识别空间体系,通过分析图像特征及运动坐标确定圆形光点,利用提供的靶点目标,创建模板后通过双目视觉获取具有靶点特征的其他图像,将图像代入OpenCV技术函数库中。在OpenCV技术函数库中通过光流法对图像进行函数匹配,应用将目标的背景模型与图像的处理方式分割开来,提取背景与干扰因素的全部信息,利用二值化阈值处理运动目标的形态,实现无干扰图像显示,确保定位结果的准确性。实验结果表明,基于OpenCV的遥操作工程机器人双目视觉定位技术能够有效提高匹配精度,降低定位误差,具有一定的实际应用价值。     

Approximate solutions for a finite moment problem

We study the problem of recovering a function whose first moments are known, possibly contaminated by noise. We evaluate accuracy and stability of a step function approximation using additional information about the L² norm of the derivative; finally we show the results of some numerical experiments.     

Models of the effect of teleoperation transmission delay on robot movement time

Abstract

Recent research of [Scholcover and Gillan (2018 Scholcover, F., and D. J. Gillan. 2018. “Using Temporal Sensitivity to Predict Performance under Latency in Teleoperation.” Human Factors 60.1:80–91. doi:10.1177/0018720817734727.[Crossref], [Web of Science ®] , [Google Scholar])] has shown experimentally that system transmission delay has a linear effect on the time taken to perform a complex tracking task with a simple teleoperated robot. This note shows that, for the case of moving a robot through a straight path, this relationship is predicted. The result is a simple modification of Drury’s law to take into account the system delay. This work extends the model for performance under intermittent illumination of Drury to the effects of fixed delays in task performance, occurring with teleoperated robots. In all cases, there was empirical evidence for the predicted linear relationship.

Practitioner summary: When there is a delay in system response for robotic teleoperation between a control input and system output, movement time (MT) is increased and the increased times are linearly related to the system delay. This is true for zero and first-order control and for delays occurring before and after the control action.     

A machine vision system for enhancing the teleoperation of an industrial robot

This paper describes a real-time vision system that enhances the teleoperation of a servicing tool used in the heat exchangers of nuclear power plants. The vision system is used to track the position of the tool as it moves over a sheet of tube ends. A map-based strategy is adopted for the estimation of the position. The system incorporates a novel method for a foreshortening correction that is applied prior to map referencing. A hypothesize and verify scheme locates two image features that correspond to two map features. An efficient scheme for extracting image features is developed to locate these two features (tube-end centers) in the image. Two different types of heat-exchanger tube sheets are accounted for. They are those with tube ends placed in a square grid and those with tube ends placed in a triangular grid. The map-based strategy minimizes the cumulative errors in the estimate of the tool head position. The resulting low-cost system has been tested on synthetic and real data. Performance results are given.     

Approximate solutions to the Lotka-Volterra competition equations†

Approximate solutions to the Lotka-Volterra competition equations are developed, permitting insight into the system behaviour without resorting to computer simulations. The accuracy of the approximate solutions is found to be quite good over a wide range of initial conditions. This is a satisfying prototype study which leads to consideration of approximate solutions for more complex, realistic biological models.     

Approximate solutions for nonlinear oscillation of a mass attached to a stretched elastic wire

In this paper, the approximate solutions of the mathematical model of a mass attached to a stretched elastic wire are presented. At the beginning of the study, the equation of motion is derived in a detailed way. He’s max–min approach, He’s frequency–amplitude method and the parameter-expansion method are implemented to solve the established model. The numerical results are further compared with the approximate analytical solutions for both a small and large amplitude of oscillations, and a very good agreement is observed. The relative errors are computed to illustrate the strength of agreement between the numerical and approximate analytical results.