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1 – 10 of 65Jing Guo, Ping Li, Huaicheng Yan and Hongliang Ren
The purpose of this paper is to design a model-based bilateral teleoperation method to improve the feedback force and velocity/position tracking for robotic-assisted tasks (such…
Abstract
Purpose
The purpose of this paper is to design a model-based bilateral teleoperation method to improve the feedback force and velocity/position tracking for robotic-assisted tasks (such as palpation, etc.) under constant and/or varying time delay with environment dynamic property. Time delay existing in bilateral teleoperation easily destabilizes the system. Proper control strategies are able to make the system stable, but at the cost of compromised performance. Model-based bilateral teleoperation is designed to achieve enhanced performance of this time-delayed system, but an accurate model is required.
Design/methodology/approach
Viscoelastic model has been used to describe the robot tool-soft tissue interaction behavior. Kevin-Boltzmann (K-B) model is selected to model the soft tissue behavior due to its good accuracy, transient and linearity properties among several viscoelastic models. In this work, the K-B model is designed at the master side to generate a virtual environment of remote robotic tool-soft tissue interaction. In order to obtain improved performance, a self perturbing recursive least square (SPRLS) algorithm is developed to on-line update the necessary parameters of the environment with varying dynamics.
Findings
With fast and optimal on-line estimation of primary parameters of the K-B model, the reflected force of the model-based bilateral teleoperation at the master side is improved as well as the position/velocity tracking performance. This model-based design in the bilateral teleoperation avoids the stability issue caused by time delay in the communication channel since the exchanged information become position/velocity and estimated parameters of the used model. Even facing with big and varying time delay, the system keeps stably and enhanced tracking performance. Besides, the fast convergence of the SPRLS algorithm helps to track the time-varying dynamic of the environment, which satisfies the surgical applications as the soft tissue properties usually are not static.
Originality/value
The originality of this work lies in that an enhanced perception of bilateral teleoperation structure under constant/varying time delay that benefits robotic assisted tele-palpation (time varying environment dynamic) tasks is developed. With SPRLS algorithm to on-line estimate the main parameters of environment, the feedback perception of system can be enhanced with stable velocity/position tracking. The superior velocity/position and force tracking performance of the developed method makes it possible for future robotic-assisted tasks with long-distance communication.
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Huiyu Sun, Guangming Song, Zhong Wei and Ying Zhang
This paper aims to tele-operate the movement of an unmanned aerial vehicle (UAV) in the obstructed environment with asymmetric time-varying delays. A simple passive proportional…
Abstract
Purpose
This paper aims to tele-operate the movement of an unmanned aerial vehicle (UAV) in the obstructed environment with asymmetric time-varying delays. A simple passive proportional velocity errors plus damping injection (P-like) controller is proposed to deal with the asymmetric time-varying delays in the aerial teleoperation system.
Design/methodology/approach
This paper presents both theoretical and real-time experimental results of the bilateral teleoperation system of a UAV for collision avoidance over the wireless network. First, a position-velocity workspace mapping is used to solve the master-slave kinematic/dynamic dissimilarity. Second, a P-like controller is proposed to ensure the stability of the time-delayed bilateral teleoperation system with asymmetric time-varying delays. The stability is analyzed by the Lyapunov–Krasovskii function and the delay-dependent stability criteria are obtained under linear-matrix-inequalities conditions. Third, a vision-based localization is presented to calibrate the UAV’s pose and provide the relative distance for obstacle avoidance with a high accuracy. Finally, the performance of the teleoperation scheme is evaluated by both human-in-the-loop simulations and real-time experiments where a single UAV flies through the obstructed environment.
Findings
Experimental results demonstrate that the teleoperation system can maintain passivity and collision avoidance can be achieved with a high accuracy for asymmetric time-varying delays. Moreover, the operator could tele-sense the force reflection to improve the maneuverability in the aerial teleoperation.
Originality/value
A real-time bilateral teleoperation system of a UAV for collision avoidance is performed in the laboratory. A force and visual interface is designed to provide force and visual feedback of the slave environment to the operator.
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The purpose of this paper is to propose a novel event-triggered aperiodic intermittent sliding-mode control (ETAI-SMC) algorithm for master–slave bilateral teleoperation robotic…
Abstract
Purpose
The purpose of this paper is to propose a novel event-triggered aperiodic intermittent sliding-mode control (ETAI-SMC) algorithm for master–slave bilateral teleoperation robotic systems to further save communication resources while maintaining synchronization precision.
Design/methodology/approach
By using the Lyapunov theory, a new event-triggered aperiodic intermittent sliding-mode controller is designed to synchronize master–slave robots in a discontinuous method. Unlike traditional periodic time-triggered continuous control strategy, a new ETAI condition is discussed for less communication pressure. Then, the exponential reaching law is adopted to accelerate sliding-mode variables convergence, which has a significant effect on synchronization performance. In addition, the authors use quantizers to make their algorithm have obvious progress in saving communication resources.
Findings
The proposed control algorithm performance is validated by an experiment developed on a practical bilateral teleoperation system with two PHANToM Omni robotic devices. As a result, the synchronization error is limited within a small range and the control frequency is evidently reduced. Compared with a conventional control algorithm, the experimental results illustrate that the proposed control algorithm is more sensitive to system states changes and it can further save communication resources while guaranteeing the system synchronization accuracy, which is more practical for real bilateral teleoperation robotic systems.
Originality/value
A novel ETAI-SMC for bilateral teleoperation robotic systems is proposed to find a balance between reducing the control frequency and synchronization control precision. Combining the traditional sliding-mode control algorithm with the periodic intermittent control strategy and the event-triggered control strategy has produced obvious effect on our control performance. The proposed ETAI-SMC algorithm helps the controller be more sensitive to system states changes, which makes it possible to achieve precise control with lower control frequency. Moreover, we design an environment contact force feedback algorithm for operators to improve the perception of the slave robot working environment. In addition, quantizers and the exponential convergence law are adopted to help the proposed algorithm perform better in saving communication resources and improving synchronization precision.
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Mehmet Dede and Sabri Tosunoglu
The objective of this study is to enhance the usage of teleoperation fields, such as in nuclear site decommissioning or nuclear waste disposal, by designing a stable, dependable…
Abstract
Purpose
The objective of this study is to enhance the usage of teleoperation fields, such as in nuclear site decommissioning or nuclear waste disposal, by designing a stable, dependable and fault‐tolerant teleoperation system in the face of “extraordinary” conditions. These “extraordinary” conditions can be classified as variable time delays in communications lines, usage of different robotic systems, component failures and changes in the system parameters during task execution.
Design/methodology/approach
This paper first gives a review of teleoperation systems developed earlier. Later, fault tolerance is proposed for use in teleoperation systems at the processor, actuator, sub‐system, and system levels. Position/force control algorithms are recommended to address stability issues when there is a loss in communications. Various other controls are also introduced to overcome the instability experienced when there is a time delay in the communications line.
Findings
Finally, this work summarizes the teleoperation system architecture and controller design options in terms of a flowchart to help in the conceptual design of such systems.
Originality/value
The impact of these new designs and algorithms will be to expand the limits and boundaries of teleoperation and a widening of its utilization area. Enhanced operation of these systems will improve system reliability and even encourage their use in more critical and diverse applications.
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Servet Soyguder and Tayfun Abut
This study attempts to control the movement of industrial robots with virtual and real-time variable time delay. The improved variable wave method was used for analyzing position…
Abstract
Purpose
This study attempts to control the movement of industrial robots with virtual and real-time variable time delay. The improved variable wave method was used for analyzing position tracking performance and stability of the system.
Design/methodology/approach
This study consists of both theoretical and real-time operations. Teleoperation systems that provide information about point or environment that people cannot reach and are one of the important robotic works that include the human–machine interaction technology were used to obtain the necessary data. Robots, as the simulated virtual environment to achieve real behaviors, were found to be important for the identification of damage that may occur during the tests performed by real robots and then in terms of prevention of errors identified in algorithm development stages.
Findings
The position and speed controls of the real–virtual–real robots consist of the teleoperation system. Also, in this study, the virtual environment was created; variable time delay motion control with teleoperation was performed and applied in the simulation and real-time environment; and the performance results were analyzed.
Originality/value
The teleoperation system created in the laboratory consists of a six-degree-of-freedom (dof) master robot, six-dof industrial robot and six-dof virtual robot. A visual interface is designed to provide visual feedback of the virtual robot’s movements to the user.
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Yushing Cheung and Jae H. Chung
This paper aims to make an industrial robot intelligently and remotely cooperate with humans to work in unknown unstructured environments.
Abstract
Purpose
This paper aims to make an industrial robot intelligently and remotely cooperate with humans to work in unknown unstructured environments.
Design/methodology/approach
Presents a bilateral adaptive teleoperation control approach involving a contact force driven compensation with an auto‐switching function, which utilizes a biologically motivated compliance function. Based on sensed contact force, the switching function can adjust its slave control input to decide how much robotic intelligences should intervene in the system by switching modes. Other schemes for robotic intelligence, robotic impedances and compensators, are investigated to guarantee good transparency without warranting human error and maintain a stable contact, based on the force feedback, in constrained motion while a communication delay exists.
Findings
The simulation and experimental results demonstrate transparency and contact stability in the presence of constant and time‐varying communication delays, respectively. The proposed bilateral adaptive teleoperation control method outperforms three other techniques.
Originality/value
This paper introduces an adaptive teleoperation control method with local robotic intelligence assistance. The developed method does not modify the existing designs of industrial robots. The contact force and position and force errors are well controlled to obtain a stable contact and transparency, through adaptation of robotic impedances.
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Omer Faruk Argin and Zeki Yagiz Bayraktaroglu
This paper aims to present a novel modular design framework for the haptic teleoperation of single-master/multiple-slave (SM/MS) systems with cooperating manipulators.
Abstract
Purpose
This paper aims to present a novel modular design framework for the haptic teleoperation of single-master/multiple-slave (SM/MS) systems with cooperating manipulators.
Design/methodology/approach
The user commands the remote-leader robot and the slave remote robot follows the leader in a leader–follower formation. The remote-slave is purely force-controlled. A virtual model of the remote environment is introduced between the local and remote environments through simulation software. Locally generated motion inputs are transmitted to the remote environment through the virtual model. A haptic coupling is designed in the virtual environment and the haptic feedback is transmitted to the user along with the forces measured in the remote environment. The controllers proposed in this work are experimentally evaluated with experienced and inexperienced users.
Findings
The proposed haptic interaction model contributes to the total force feedback and smoothens the high-frequency signals occurring at the physical interaction in the remote environment. Experimental results show that the implemented controllers including the proposed haptic interaction improve the teleoperation performances in terms of trajectory tracking. Furthermore, pure force control of the remote-slave is shown to enhance the robustness of the teleoperation against external disturbances. Satisfactory teleoperation performances are observed with both experienced and inexperienced users.
Originality/value
The proposed SM/MS teleoperation system involves a multi-purpose virtual simulator and a purely force-controlled remote-slave manipulator in a modular cooperative configuration. The uniquely defined structure of the proposed haptic coupling is used in modeling the interaction between the local and remote manipulators on the one hand, and between cooperating remote manipulators on the other.
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Tayfun Abut and Servet Soyguder
This paper aims to use the adaptive computed torque control (ACTC) method to eliminate the kinematic and dynamic uncertainties of master and slave robots and for the control of…
Abstract
Purpose
This paper aims to use the adaptive computed torque control (ACTC) method to eliminate the kinematic and dynamic uncertainties of master and slave robots and for the control of the system in the presence of forces originating from human and environment interaction.
Design/methodology/approach
In case of uncertainties in the robot parameters that are utilized in teleoperation studies and when the environment where interactions take place is not known and when there is a time delay, very serious problems take place in system performance. An adaptation rule was created to update uncertain parameters. In addition to this, disturbance observer was designed for slave robot. Lyapunov function was used to analyze the system’s position tracking and stability. A visual interface was designed to ensure that the movements of the master robot provided a visual feedback to the user.
Findings
In this study, a visual interface was created, and position and velocity control was achieved utilizing teleoperation; the system’s position tracking and stability were analyzed using the Lyapunov method; a simulation was applied in a real-time environment, and the performance results were analyzed.
Originality/value
This study consisted of both simulation and real-time studies. The teleoperation system, which was created in a laboratory environment, consisted of six-degree-of-freedom (DOF) master robots, six-DOF industrial robots and six-DOF virtual robots.
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Adha Imam Cahyadi and Yoshio Yamamoto
The purpose of this paper is to present a design and verification through experiments of teleoperation of the 3 degrees‐of‐freedom micromanipulation system (MMS), in laboratory…
Abstract
Purpose
The purpose of this paper is to present a design and verification through experiments of teleoperation of the 3 degrees‐of‐freedom micromanipulation system (MMS), in laboratory conditions.
Design/methodology/approach
The MMS is constructed from piezoelectric actuators sited in a flexure hinge mechanism. The nonlinearity, especially hysteresis, due to a voltage steering scheme is compensated for, via a second‐order Dahl friction model. A simple mechanical model is then constructed to capture the behavior of the MMS. Redundant force feedback sensors are applied to the MMS in order to achieve flexible operation via the so‐called fault‐tolerancing mechanism. Finally, a teleoperation scheme based on passivity formalism is proposed to achieve a stable teleoperation system.
Findings
The hysteresis curve due to voltage steering can be minimized. The fault‐tolerancing concept using redundant sensors for comfortable use of the MMS has been successfully performed. The teleoperated MMS via a commercially available PHANToM® has been conducted under ineligible telecommunication channel delay.
Originality/value
The details of design, modelling and experimentations of the teleoperation of the MMS should promote the applicability of similar systems in the future.
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A. Shirinov, J. Kamenik and S. Fatikow
Miniaturised nanohandling microrobots are used to handle objects of less than 100 μm size with accuracy down to several nanometres. Operating a nanohandling robot in the…
Abstract
Miniaturised nanohandling microrobots are used to handle objects of less than 100 μm size with accuracy down to several nanometres. Operating a nanohandling robot in the microworld and nanoworld presents challenges not found in the macroworld. To allow a good manipulability, we propose a teleoperation system, which is based on the innovative approach of haptic‐based model‐oriented teleoperation of nanohandling robots. The newly developed haptic interface for a microrobot cell is used in the proposed teleoperation system for the teleoperation of the industrial nanohandling robot. This paper presents the scanning electron microscope based nanohandling station that uses the proposed haptic‐based model‐oriented teleoperation approach. Further, we discuss the integration of a force microsensor into the teleoperation interface. The first experiments and theoretical research show that the proposed approach can improve haptic‐based teleoperation of nanohandling robots.
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