工业机器人遥操作系统的空间映射与控制策略

针对工业机器人遥操作系统中存在的主从机器人工作空间差异以及运动控制精度与安全问题,提出了一种工作空间映射算法与位置—速度混合控制策略。首先,将遥操作划分为自由运动和交互两个阶段,在自由运动阶段采用映射算法使主从机器人的工作空间高度覆盖,使主机器人可操控的从机器人运动范围最大化。进一步,在交互阶段设计了一种位置—速度混合控制策略对工业机器人的运动进行准确的控制,使主从机器人的实际位置轨迹准确的跟随,并进一步引入反馈引导力以实现安全的控制。最后在Touch-ABB IRB120主从机器人遥操作实验平台上对所提控制方法进行验证,实验结果表明该方法使得主从机器人运动范围在高度覆盖的同时可以保证遥操作控制的精度。     

Evaluating a workspace’s usefulness for image retrieval

Image searching is a creative process. We have proposed a novel image retrieval system that supports creative search sessions by allowing the user to organise their search results on a workspace. The workspace’s usefulness is evaluated in a task-oriented and user-centred comparative experiment, involving design professionals and several types of realistic search tasks. In particular, we focus on its effect on task conceptualisation and query formulation. A traditional relevance feedback system serves as a baseline. The results of this study show that the workspace is more useful in terms of both of the above aspects and that the proposed approach leads to a more effective and enjoyable search experience. This paper also highlights the influence of tasks on the users’ search and organisation strategy.     

外骨骼式遥操作主手设计及主从异构映射算法研究

为了更好地促进机器人适应复杂的遥操作任务,开发了能够精确获取人体上肢运动信息的外骨骼式遥操作主手,并通过异构映射算法,实现对6自由度协作机械臂的遥操作．首先,基于人体仿生结构,设计了可穿戴式8自由度外骨骼主手（臂部7自由度和手部1自由度）;其次,通过改进的D-H（Denavit-Hartenberg）方法建立遥操作系统的运动学模型,基于Matlab的机器人工具箱进行了工作空间仿真,并设计主从异构映射算法;最后,实验验证外骨骼主手在遥操作系统中的可操作性,以及工作空间异构映射算法的可行性．实验表明,外骨骼主手能够控制从端机械手臂,且保证末端位置和姿态一致,可在大范围工作空间内复现人体上肢精细运动,主从跟随误差达2 mm,工作空间类似于直径1.08 m的半球形．因此,可穿戴式的外骨骼主手使操作者能更加直观地参与到遥操作系统当中,辅助操作者更加高效地完成精细复杂任务．     

Automatic Viewpoint Planning in Teleoperation of a Mobile Robot

Camera viewpoint has significant impact on operators situation awareness in teleoperation. This paper presents a method for automatic optimal positioning of a single camera for a remotely navigated mobile robot in systems with a controllable camera platform. The proposed algorithm continuously adjusts the camera view of the workspace based on the task circumstances, allowing the operator to focus mainly on navigation and manipulation. The workspace and motion limits of the camera system and the location of the obstacles are taken into consideration in the camera view planning by formulating and solving a constrained optimization problem in real-time. A head tracking system enables the operator to use his/her head movements as an extra control input to guide the camera placement, if and when necessary. The proposed viewpoint control framework has been implemented and evaluated in a teleoperation experiment with a mobile robot. Results of a user study comparing this approach to two other common viewpoint control strategies are also reported.     

Active-Vision for the Autonomous Surveillance of Dynamic,Multi-Object Environments

This paper presents a novel method for active-vision-based sensing-system reconfiguration for the autonomous surveillance of an object-of-interest as it travels through a multi-object dynamic workspace with an a priori unknown trajectory. Several approaches have been previously proposed to address the problem of sensor selection and control. However, these have primarily relied on off-line planning methods and rarely utilized on-line planning to compensate for unexpected variations in a target’s trajectory. The method proposed in this paper, on the other hand, uses a multi-agent system for on-line sensing-system reconfiguration, eliminating the need for any a priori knowledge of the target’s trajectory. Thus, it is robust to unexpected variations in the environment. Simulations and experiments have shown that the use of dynamic sensors with the proposed on-line reconfiguration algorithm can tangibly improve the performance of an active-surveillance system.      

Neural Network Solution for Forward Kinematics Problem of Cable Robots

Forward kinematics problem of cable robots is very difficult to solve the same as that of parallel robots and in the contrary to the serial manipulators’. This problem is almost impossible to solve analytically because of the nonlinearity and complexity of the robot’s kinematic equations. Numerical methods are the most common solutions for this problem of the parallel and cable robots. But, convergency of these methods is the drawback of using them. In this paper, neural network approach is used to solve the forward kinematics problem of an exemplary 3D cable robot. This problem is solved in the typical workspace of the robot. The neural network used in this paper is of the MLP type and a back propagation procedure is utilized to train the network. A simulation study is performed and the results show the advantages of this method in enhancement of convergency together with very small modeling errors.     

Analysis of kinematics/statics and workspace of a 2(SP+SPR+SPU) serial–parallel manipulator

The kinematics/statics and workspace of a 2(SP+SPR+SPU) serial–parallel manipulator are studied systematically. First, a 2(SP+SPR+SPU) manipulator including an upper and a lower SP+SPR+SPU parallel manipulators is constructed, and the inverse/forward displacements, velocity, acceleration and statics of the lower/upper parallel manipulators are studied, respectively. Second, the kinematics and statics of the lower/upper manipulators are combined and the displacement, velocity, acceleration, statics, and workspace of a 2(SP+SPR+SPU) manipulator are analyzed systematically. Third, the analytic solutions’ examples are given and verified by the simulation mechanism. This manipulator has some potential applications for the robot’s arm, leg, and twist, the serial–parallel machine tools, the sensor, the surgical manipulator, the tunnel borer, the barbette of warship, and the satellite surveillance platform.     

A Telepresence-Guaranteed Control Scheme for Teleoperation Applications of Transferring Weight-Unknown Objects

Currently, most teleoperation work is focusing on scenarios where slave robots interact with unknown environments. However, in some fields such as medical robots or rescue robots, the other typical teleoperation application is precise object transportation. Generally, the object’s weight is unknown yet essential for both accurate control of the slave robot and intuitive perception of the human operator. However, due to high cost and limited installation space, it is unreliable to employ a force sensor to directly measure the weight. Therefore, in this paper, a control scheme free of force sensor is proposed for teleoperation robots to transfer a weight-unknown object accurately. In this scheme, the workspace mapping between master and slave robot is firstly established, based on which, the operator can generate command trajectory on-line by operating the master robot. Then, a slave controller is designed to follow the master command closely and estimate the object’s weight rapidly, accurately and robust to unmodeled uncertainties. Finally, for the sake of telepresence, a master controller is designed to generate force feedback to reproduce the estimated weight of the object. In the end, comparative experiments show that the proposed scheme can achieve better control accuracy and telepresence, with accurate force feedback generated in only 500 ms.      

A low-cost internet-based telerobotic system for access to remote laboratories

This paper presents an account of the design of a low-cost Internet-based teleoperation system implemented on China's Internet. Using a multimedia-rich human-computer interface, combining predictive displays and graphical overlays, a series of simple tasks were performed within a simulated space environment scenario. Internet clients anywhere can monitor the robotic workspace, talk with technicians, and control the Arm/Hand integrated system with 15 DOF located in lab to perform tasks (such as grasping a vessel, pouring a liquid, and peg-in-hole assembling, etc.). Our main contributions are to establish a foundation for teleoperated science and engineering research, and we have addressed some issues involving the time-delay associated with the Internet. We also developed several key software adaptation technologies and products used for Internet-Based teleoperation, compatible with the BH-III dexterous hand, BH1 6-DOF mechanical arm and five-finger 11-DOF data glove, constructed in our laboratory. This system has been successfully tested and applied in remote robotic education (Virtual Laboratories) system via China's Internet using our Master/Slave architecture, which combines mixed modes of remote monitor/manipulate and local autonomous control.     

Maximum DLCC of Spatial Cable Robot for a Predefined Trajectory Within the Workspace Using Closed Loop Optimal Control Approach

One of the most important applications of cable robots is load carrying along a specific path. Control procedure of cable robots is more challenging compared to linkage robots since cables can’t afford pressure. Meanwhile carrying the heaviest possible payload for this kind of robots is desired. In this paper a nonlinear optimal control is proposed in order to control the end-effector within a predefined trajectory while the highest Dynamic Load Carrying Capacity (DLCC) can be carried. This purpose is met by applying optimum torque distribution among the motors with acceptable tracking accuracy. Besides, other algorithms are applied to make sure that the allowable workspace constraint is also satisfied. Since the dynamics of the robot is nonlinear, feedback linearization approach is employed in order to control the end-effector on its desirable path in a closed loop way while Linear Quadratic Regulator (LOR) method is used in order to optimize its controlling gains since the state space is linearized by the feedback linearization. The proposed algorithm is supported by doing some simulation studies on a two Degrees of Freedom (DOF) constrained planar cable robot as well as a six DOFs under constrained cable suspended robot and their DLCCs are calculated by satisfying the motor torque, tracking error and allowable workspace constraints. The results including the angular velocity, motors’ torque, actual tracking of the end-effector and the DLCC of the robot are calculated and verified using experimental tests done on the cable robot. Comparison of the results of open loop simulation results, closed loop simulation results and experimental tests, shows that the results are improved by applying the proposed algorithm. This is the result of tuning the motors’ torque and accuracy in a way that the highest DLCC can be achieved.     

Superpositioning of behaviors learned through teleoperation

This paper reports that the superposition of a small set of behaviors, learned via teleoperation, can lead to robust completion of an articulated reach-and-grasp task. The results support the hypothesis that a robot can learn to interact purposefully with its environment through a developmental acquisition of sensory-motor coordination. Teleoperation can bootstrap the process by enabling the robot to observe its own sensory responses to actions that lead to specific outcomes within an environment. It is shown that a reach-and-grasp task, learned by an articulated robot through a small number of teleoperated trials, can be performed autonomously with success in the face of significant variations in the environment and perturbations of the goal. In particular, teleoperation of the robot to reach and grasp an object at nine different locations in its workspace enabled robust autonomous performance of the task anywhere within the workspace. Superpositioning was performed using the Verbs and Adverbs algorithm that was developed originally for the graphical animation of articulated characters. The work was performed on Robonaut, the NASA space-capable humanoid at Johnson Space Center, Houston, TX.     

Approximate solutions to unreachable commands in teleoperation of a robot

A method is presented for finding approximate solutions to unreachable commands for a serial link manipulator. It deals with the difficulties of joint limits and singularities in a teleoperational, task space controller. Damped least squares with dynamic weighting is used to solve the inverse Jacobian problem. Previously reported benefits of damped least squares are reviewed, and an additional benefit is demonstrated; a convergence to an approximate position when the command is outside a singularity-defined workspace boundary. The utility of damped least squares is extended by incorporating dynamic weighting matrices, allowing an approximate position to be found when the command is outside a joint-limit-defined workspace boundary. A real-time control scheme for calculating the dynamic weights and damping factor is presented. A hardware implementation, that used a six degree of freedom teleoperator, is discussed. In this implementation the approximate position solution, a new concept in dealing with workspace boundaries in teleoperation, resulted in improved operation.     

Integration of humanoid robots in collaborative working environment: a case study on motion generation

This paper illustrates through a practical example an integration of a humanoid robotic architecture, with an open-platform collaborative working environment called BSCW (Be Smart-Cooperate Worldwide). BSCW is primarily designed to advocate a futuristic shared workspace system for humans. We exemplify how a complex robotic system (such as a humanoid robot) can be integrated as a proactive collaborative agent which provides services and interacts with other agents sharing the same collaborative environment workspace. Indeed, the robot is seen as a ‘user’ of the BSCW which is able to handle simple tasks and reports on their achievement status. We emphasis on the importance of using standard software such as CORBA (Common Object Request Broker Architecture) in order to easily build interfaces between several interacting complex software layers, namely from real-time constraints up to basic Internet data exchange.     

Investigating the Role of a Large,Shared Display in Multi-Display Environments

We conducted an empirical study to investigate the use of personal and shared displays during group work. The collaborative environments under study consisted of personal workspaces, in the form of laptops, and a shared virtual workspace displayed on a nearby wall. Our study compared the use of the large shared display under two different interface content conditions; a status display that provided an overview of the group’s current task performance, and a replicated view of the shared workspace that allowed task work to occur on the shared display. The study results suggest that while participants used their personal displays primarily to perform the task, the shared display facilitated several key teamwork mechanisms. In particular, the provided status display best facilitated monitoring of group progress, whereas the replicated content display best facilitated conversational grounding. Regardless of the shared display content, having a shared, physical reference point also appeared to support synchronization of the group activity via body language and gaze.     

Optical merger of direct vision with virtual images for scaled teleoperation

Scaled teleoperation is increasingly prevalent in medicine, as well as in other applications of robotics. Visual feedback in such systems is essential and should make maximal use of natural hand-eye coordination. This paper describes a new method of visual feedback for scaled teleoperation in which the operator manipulates the handle of a remote tool in the presence of a registered virtual image of the target in real time. The method adapts a concept already used successfully in a new medical device called the sonic flashlight, which permits direct in situ visualization of ultrasound during invasive procedures. The sonic flashlight uses a flat-panel monitor and a half-silvered mirror to merge the visual outer surface of a patient with a simultaneous ultrasound scan of the patient's interior. Adapting the concept to scaled teleoperation involves removing the imaging device and the target to a remote location and adding a master-slave control device. This permits the operator to see his hands, along with what appears to be the tool, and the target, merged in a workspace that preserves natural hand-eye coordination. Three functioning prototypes are described, one based on ultrasound and two on light microscopy. The limitations and potential of the new approach are discussed.     

Conceptualizing the Awareness of Collaboration: A Qualitative Study of a Global Virtual Team

Innovative organizations are increasing their use of distributed teamwork, but there are several difficulties in reaching shared understanding between the team members in these settings. A lack of awareness of other team members’ working processes is one of the drawbacks that a virtual team may face while attempting to collaborate on a shared task. In this study virtual teamwork was supported with a specific working model. The aim was to investigate virtual team members’ awareness of collaboration. One global team (N=19) within a single organization worked as a distributed team in a shared web-based workspace for three months. The data were gathered by means of questionnaires, log-files of the shared virtual workspace and collected company documents in order to find out how team members perceive their collaboration. Based on qualitative data analysis, three different aspects of collaboration awareness were identified: an awareness of the possibility for collaboration, an awareness of the aims of collaboration, and an awareness of the process of collaboration. The results presented in this paper give guidelines for discussing what the awareness of collaboration means in the context of distributed collaboration.     

Exploration of 2D and 3D Environments using Voronoi Transform and Fast Marching Method

Robot navigation in unknown environments requires an efficient exploration method. Exploration involves not only to determine towards the robot must to move but also motion planning, and simultaneous localization and mapping processes. The final goal of the exploration task is to build a map of the environment that previously the robot didn’t know. This work proposes the Voronoi Fast Marching method, that uses a Fast Marching technique on the Logarithm of the Extended Voronoi Transform of the environment’s image provided by sensors, to determine a motion plan. The Logarithm of the Extended Voronoi Transform imitates the repulsive electric potential from walls and obstacles, and the Fast Marching Method propagates a wave over that potential map. The trajectory is calculated by the gradient method. The robot is directed towards the most unexplored and free zones of the environment so as to be able to explore all the workspace. Finally, to build the environment map while the robot is carrying out the exploration task, a SLAM (Simultaneous Localization and Modelling)algorithm is implemented, the Evolutive Localization Filter (ELF) based on a differential evolution technique. The combination of these methods provide a new autonomous exploration strategy to construct consistent maps of 2D and 3D indoor environments.     

Spatial Modelling for Mobile Robot’s Vision-based Navigation

We present an algorithm to model 3D workspace and to understand test scene for mobile robot’s navigation or human computer interaction. This has done by line-based modeling and recognition algorithm. Line-based recognition using 3D lines has been tried by many researchers however its reliability still needs improvement due to ambiguity of 3D line feature information from original images. To improve the outcome, we approach firstly to find real planes using given 3D lines and then to implement recognition process. The methods we use are principle component analysis (PCA), plane sweep, occlusion query, and iterative closest point (ICP). During the implementation, we also use 3D map information for localization. We apply this algorithm to real test scene images and find out our result can be useful to identify doors or walls in indoor environment with better efficiency.     

Intuitive robot teleoperation for civil engineering operations with virtual reality and deep learning scene reconstruction

Robotic teleoperation, i.e., manipulating remote robotic systems at a distance, has gained its popularity in various industrial applications, including construction operations. The key to a successful teleoperation robot system is the delicate design of the human-robot interface that helps strengthen the human operator’s situational awareness. Traditional human-robot interface for robotic teleoperation is usually based on imagery data (e.g., video streaming), causing the limited field of view (FOV) and increased cognitive burden for processing additional spatial information. As a result, 3D scene reconstruction methods based on point cloud models captured by scanning technologies (e.g., depth camera and LiDAR) have been explored to provide immersive and intuitive feedback to the human operator. Despite the added benefits of applying reconstructed 3D scenes in telerobotic systems, challenges still present. Most 3D reconstruction methods utilize raw point cloud data due to the difficulty of real-time model rendering. The significant size of point cloud data makes the processing and transfer between robots and human operators difficult and slow. In addition, most reconstructed point cloud models do not contain physical properties such as weight and colliders. A more enriched control mechanism based on physics engine simulations is impossible. This paper presents an intelligent robot teleoperation interface that collects, processes, transfers, and reconstructs the immersive scene model of the workspace in Virtual Reality (VR) and enables intuitive robot controls accordingly. The proposed system, Telerobotic Operation based on Auto-reconstructed Remote Scene (TOARS), utilizes a deep learning algorithm to automatically detect objects in the captured scene, along with their physical properties, based on the point cloud data. The processed information is then transferred to the game engine where rendered virtual objects replace the original point cloud models in the VR environment. TOARS is expected to significantly improve the efficiency of 3D scene reconstruction and situational awareness of human operators in robotic teleoperation.     

A shared workspace to support man–machine reasoning: application to cooperative distant diagnosis

This paper focuses on man–machine cooperation problems. In particular, it deals with those problems that occur when both human and machine have to achieve a shared reasoning activity. It puts forward a man–machine approach that is dedicated to technical diagnosis problem solving. Coordination of human and automated reasoning is key to solving this problem, since efficiency depends on both sharing and interpreting exchanged data. A shared workspace is proposed to support both machines and their human operators. This workspace is kept as close as possible to human representations in order to reduce cooperation costs. The paper describes those coordination mechanisms that are able to support such a cooperative activity using a shared workspace. In order to assess the costs and benefits of such cooperation, these mechanisms are applied to a complex industrial problem: diagnosis and troubleshooting in a phone network. The results show the full impact of cooperation on human–machine reasoning.