In some complicated tabletop object manipulation task for robotic system, demonstration based control is an efficient way to enhance the stability of execution. In this paper, we use a new optical hand tracking sensor...In some complicated tabletop object manipulation task for robotic system, demonstration based control is an efficient way to enhance the stability of execution. In this paper, we use a new optical hand tracking sensor, LeapMotion, to perform a non-contact demonstration for robotic systems. A Multi-LeapMotion hand tracking system is developed. The setup of the two sensors is analyzed to gain a optimal way for efficiently use the informations from the two sensors. Meanwhile, the coordinate systems of the Mult-LeapMotion hand tracking device and the robotic demonstration system are developed. With the recognition to the element actions and the delay calibration, the fusion principles are developed to get the improved and corrected gesture recognition. The gesture recognition and scenario experiments are carried out, and indicate the improvement of the proposed Multi-LeapMotion hand tracking system in tabletop object manipulation task for robotic demonstration.展开更多
Contactless manipulation of multi-scale objects using the acoustic vortex(AV) tweezers offers tremendous perspectives in biomedical applications.However,it is still hindered by the weak acoustic radiation force(ARF) a...Contactless manipulation of multi-scale objects using the acoustic vortex(AV) tweezers offers tremendous perspectives in biomedical applications.However,it is still hindered by the weak acoustic radiation force(ARF) and torque(ART)around the vortex center.By introducing the elevation angle to the planar transducers of an N-element ring array,the weakfocused acoustic vortex(WFAV) composed of a main-AV and N paraxial-AVs is constructed to conduct a large-scale object manipulation.Different from the traditional focused AV(FAV) generated by a ring array of concave spherical transducers,a much larger focal region of the WFAV is generated by the main lobes of the planar transducers with the size inversely associated with the elevation angle.With the pressure simulation of the acoustic field,the capability of the rotational object driving in the focal plane for the WFAV is analyzed using the ARF and the ART exerted on an elastic ball based on acoustic scattering.With the experimental system built in water,the generation of the WFAV is verified by the scanning measurements of the acoustic field and the capability of object manipulation is also analyzed by the rotational trapping of floating particles in the focal plane.The favorable results demonstrate the feasibility of large-scale rotational manipulation of objects with a strengthened ART and a reduced acousto-thermal damage to biological tissues,showing a promising prospect for potential applications in clinical practice.展开更多
A concurrency control mechanism for collaborative work is akey element in a mixed reality environment. However, conventional lockingmechanisms restrict potential tasks or the support of non-owners, thusincreasing the ...A concurrency control mechanism for collaborative work is akey element in a mixed reality environment. However, conventional lockingmechanisms restrict potential tasks or the support of non-owners, thusincreasing the working time because of waiting to avoid conflicts. Herein, wepropose an adaptive concurrency control approach that can reduce conflictsand work time. We classify shared object manipulation in mixed reality intodetailed goals and tasks. Then, we model the relationships among goal,task, and ownership. As the collaborative work progresses, the proposedsystem adapts the different concurrency control mechanisms of shared objectmanipulation according to the modeling of goal–task–ownership. With theproposed concurrency control scheme, users can hold shared objects andmove and rotate together in a mixed reality environment similar to realindustrial sites. Additionally, this system provides MS Hololens and Myosensors to recognize inputs from a user and provides results in a mixed realityenvironment. The proposed method is applied to install an air conditioneras a case study. Experimental results and user studies show that, comparedwith the conventional approach, the proposed method reduced the number ofconflicts, waiting time, and total working time.展开更多
Holograms provide a characteristic manner to display and convey information, and have been improved to provide better user interactions Holographic interactions are important as they improve user interactions with vir...Holograms provide a characteristic manner to display and convey information, and have been improved to provide better user interactions Holographic interactions are important as they improve user interactions with virtual objects. Gesture interaction is a recent research topic, as it allows users to use their bare hands to directly interact with the hologram. However, it remains unclear whether real hand gestures are well suited for hologram applications. Therefore, we discuss the development process and implementation of three-dimensional object manipulation using natural hand gestures in a hologram. We describe the design and development process for hologram applications and its integration with real hand gesture interactions as initial findings. Experimental results from Nasa TLX form are discussed. Based on the findings, we actualize the user interactions in the hologram.展开更多
This paper presents a learning-based control framework for fast(<1.5 s)and accurate manipulation of a flexible object,i.e.,whip targeting.The framework consists of a motion planner learned or optimized by an algori...This paper presents a learning-based control framework for fast(<1.5 s)and accurate manipulation of a flexible object,i.e.,whip targeting.The framework consists of a motion planner learned or optimized by an algorithm,Online Impedance Adaptation Control(OIAC),a sim2real mechanism,and a visual feedback component.The experimental results show that a soft actor-critic algorithm outperforms three Deep Reinforcement Learning(DRL),a nonlinear optimization,and a genetic algorithm in learning generalization of motion planning.It can greatly reduce average learning trials(to<20 of others)and maximize average rewards(to>3 times of others).Besides,motion tracking errors are greatly reduced to 13.29 and 22.36 of constant impedance control by the OIAC of the proposed framework.In addition,the trajectory similarity between simulated and physical whips is 89.09.The presented framework provides a new method integrating data-driven and physics-based algorithms for controlling fast and accurate arm manipulation of a flexible object.展开更多
Deformable manipulation has attracted a lot of attention in the field of robotics,especially in medical applications.However,manipulating deformable objects faces various challenges,mainly including their complex dyna...Deformable manipulation has attracted a lot of attention in the field of robotics,especially in medical applications.However,manipulating deformable objects faces various challenges,mainly including their complex dynamic properties and unpredictable nonlinear deformations.It is difficult to provide a basis for deformable object measurements without effective control methods that provide intelligent and accurate position control,and this research also provides a premise for deformable object measurements.To address these issues,this paper proposes an online iterative perception policy(IPP)method,which does not require large-scale deep network training.This method is able to perceive transformations through an iterative process,and achieve efficient and accurate control of deformable objects.Extensive experiments in the simulation environment and the real scene are conducted to validate the effectiveness and superiority of the proposed method,as well as to compare with advanced algorithms(linear–quadratic regulator(LQR),sliding mode control(SMC),model predictive control(MPC),and heuristic).The experimental results reveal that IPP outperforms other approaches in terms of convergence,stability,robustness and flexibility in both the simulation and real-world scenarios,regardless of textile properties or initial conditions.展开更多
Purpose: The primary aim of this study was to develop an assessment of the fundamental, combined, and complex movement skills required to support childhood physical literacy. The secondary aim was to establish the fea...Purpose: The primary aim of this study was to develop an assessment of the fundamental, combined, and complex movement skills required to support childhood physical literacy. The secondary aim was to establish the feasibility, objectivity, and reliability evidence for the assessment.Methods: An expert advisory group recommended a course format for the assessment that would require children to complete a series of dynamic movement skills. Criterion-referenced skill performance and completion time were the recommended forms of evaluation. Children, 8–12 years of age, self-reported their age and gender and then completed the study assessments while attending local schools or day camps. Face validity was previously established through a Delphi expert(n = 19, 21% female) review process. Convergent validity was evaluated by age and gender associations with assessment performance. Inter-and intra-rater(n = 53, 34% female) objectivity and test–retest(n = 60, 47% female) reliability were assessed through repeated test administration.Results: Median total score was 21 of 28 points(range 5–28). Median completion time was 17 s. Total scores were feasible for all 995 children who self-reported age and gender. Total score did not differ between inside and outside environments(95% confidence interval(CI) of difference:-0.7 to 0.6;p = 0.91) or with/without footwear(95%CI of difference:-2.5 to 1.9; p = 0.77). Older age(p < 0.001, η2= 0.15) and male gender(p < 0.001, η2= 0.02)were associated with a higher total score. Inter-rater objectivity evidence was excellent(intraclass correlation coefficient(ICC) = 0.99) for completion time and substantial for skill score(ICC = 0.69) for 104 attempts by 53 children(34% female). Intra-rater objectivity was moderate(ICC = 0.52) for skill score and excellent for completion time(ICC = 0.99). Reliability was excellent for completion time over a short(2–4 days; ICC = 0.84) or long(8–14days; ICC = 0.82) interval. Skill score reliability was moderate(ICC = 0.46) over a short interval, and substantial(ICC = 0.74) over a long interval.Conclusion: The Canadian Agility and Movement Skill Assessment is a feasible measure of selected fundamental, complex and combined movement skills, which are an important building block for childhood physical literacy. Moderate-to-excellent objectivity was demonstrated for children 8–12 years of age. Test–retest reliability has been established over an interval of at least 1 week. The time and skill scores can be accurately estimated by 1 trained examiner.展开更多
Automated parallel manipulation of multiple micro-objects with optoelectronic tweezers(OET)has brought significant research interests recently.However,the parallel manipulation of multiple objects in complex obstacle-...Automated parallel manipulation of multiple micro-objects with optoelectronic tweezers(OET)has brought significant research interests recently.However,the parallel manipulation of multiple objects in complex obstacle-dense microenvironment using OET technology based on negative dielectrophoresis(nDEP)remain a big technical challenge.In this work,we proposed an adaptive light pattern design strategy to achieve automated parallel OET manipulation of multiple micro-objects and navigate them through obstacles to target positions with high precision and no collision.We first developed a multi-micro-object parallel manipulation OET system,capable of simultaneous image processing and microparticles path planning.To overcome microparticle collisions caused by overlapping light patterns,we employed a novel adaptive light pattern design that can dynamically adjust the layout of overlapping light patterns according to surrounding environment,ensuring enough space for each microparticle and preventing unintended escapes from the OET trap.The efficacy of this approach has been verified through systematic simulations and experiments.Utilizing this strategy,multiple polystyrene microparticles were autonomously navigated through obstacles and microchannels to their intended destinations,demonstrating the strategy’s effectiveness and potential for automated parallel micromanipulation of multiple microparticles in complex and confined microenvironments.展开更多
A view in object oriented databases corresponds to virtual schemawith restructured generalization and decomposition hierarchies. Numbers of viewcreation methodologies have been proposed. A major drawback of existing m...A view in object oriented databases corresponds to virtual schemawith restructured generalization and decomposition hierarchies. Numbers of viewcreation methodologies have been proposed. A major drawback of existing method-ologies is that they do not maintain the closure property. That is, the result of aquery does not have the same semantics as embodied in the object oriented datamodel. Therefore, this paper presents a view creation methodology that derives aclass in response to a user's query, integrates derived class in global schema (i.e.,considers the problem of classes moving in class hierarchy) and selects the requiredclasses from global schema to create the view for user's query. Novel idea of viewcreation includes: (a) an object algebra for class derivation and customization (wherethe derived classes in terms of object instances and procedure/methods are studied),(b) maintenance of closure property, and (c) classification algorithm which providesmechanism to deal with the problem of a class moving in a class hierarchy.展开更多
This review paper presents a comprehensive evaluation and forward-looking perspective on the underexplored topic of servicing target objects using spacecraft swarms.Such targets can be known or unknown,cooperative or ...This review paper presents a comprehensive evaluation and forward-looking perspective on the underexplored topic of servicing target objects using spacecraft swarms.Such targets can be known or unknown,cooperative or uncooperative,and pose significant challenges in modern space operations due to their inherent complexity and unpredictability.Successfully servicing space objects is vital for active debris removal and broader on-orbit servicing tasks such as satellite maintenance,repair,refueling,orbital assembly,and construction.Significant effort has been invested in the literature to explore the servicing of targets using a single spacecraft.Given its advantages and benefits,this paper expands the discussion to encompass a swarm approach to the problem.This review covers various single-spacecraft approaches and presents a critical examination of the existing,although limited,body of work dedicated to servicing orbital objects using multiple spacecraft.The focus is also broadened to include some influential studies concerning the characterization,capture,and manipulation of physical objects by general multiagent systems,a subject with significant parallels to the core interest of this manuscript.Furthermore,this article also delves into the realm of simultaneous localization and mapping,highlighting its application within close-proximity operations in space,especially when dealing with unknown uncooperative targets.Special attention is paid to the benefits that this field can receive from distributed multiagent architectures.Finally,an exploration of the promising field of swarm robotics is presented,with an emphasis on its potential to revolutionize the servicing of orbital target objects.Concurrently,a survey of general research directly engaging swarms in the orbital context is conducted.This review aims to bridge the knowledge gap and stimulate further research in the underexplored domain of servicing space targets with spacecraft swarms.展开更多
Telekinesis,as commonly portrayed in science fiction literature and cinema,is a super power wherein users control and manipulate objects absent in physical interaction.In real world,enhancing human–robot interaction ...Telekinesis,as commonly portrayed in science fiction literature and cinema,is a super power wherein users control and manipulate objects absent in physical interaction.In real world,enhancing human–robot interaction needs the synthesis of human intuitive processes with robotic arm.This paper introduces a robotic teleoperation system achieving the essence of telekinetic operations,combining the profound capabilities of augmented reality(AR)with the robotic arm operations.Utilizing AR,the proposed methodology offers operators with a visual feedback,facilitating a level of control surpassing the capacities of natural interfaces.By using AR-driven visual recognition,this system achieves operations in a virtual environment,subsequently actualized in the real world through the robotic arm.Through multiple experiments,we found that the system has a small margin of error in telekinesis operations,meeting the needs of remote operation.Furthermore,our system can operate on objects in the real world.These experiments underscore the capability of the remote control system to assist humans in accomplishing a wider range of tasks through the integration of AR and robotic arms,providing a natural human–robot interaction approach.展开更多
Variable Impedance control allows robots and humans to safely and efficiently interact with unknown external environments.This tutorial introduces online impedance adaptation control(OIAC)for variable compliant joint ...Variable Impedance control allows robots and humans to safely and efficiently interact with unknown external environments.This tutorial introduces online impedance adaptation control(OIAC)for variable compliant joint motions in a range of control tasks:rapid(<1 s)movement control(i.e.,whipping to hit),arm and finger impedance quantification,multifunctional exoskeleton control,and robot-inspired human arm control hypothesis.The OIAC has been introduced as a feedback control,which can be integrated into a feedforward control,e.g.,learned by data-driven methods.This integration facilitates the understanding of human and robot arm control,closing a research loop between biomechanics and robotics.It shows not only a research way from biomechanics to robotics,but also another reserved one.This tutorial aims at presenting research examples and Python codes for advancing the understanding of variable impedance adaptation in human and robot motor control.It contributes to the state-of-the-art by providing an online impedance adaptation controller for wearable robots(i.e.,exoskeletons)which can be used in robotic and biomechanical applications.展开更多
基金This research is funded by National Natural Science Foundation of China under Project no. 61210013, Science and Technology Planning Project of Guangdong Province under no. 2014A020215027.
文摘In some complicated tabletop object manipulation task for robotic system, demonstration based control is an efficient way to enhance the stability of execution. In this paper, we use a new optical hand tracking sensor, LeapMotion, to perform a non-contact demonstration for robotic systems. A Multi-LeapMotion hand tracking system is developed. The setup of the two sensors is analyzed to gain a optimal way for efficiently use the informations from the two sensors. Meanwhile, the coordinate systems of the Mult-LeapMotion hand tracking device and the robotic demonstration system are developed. With the recognition to the element actions and the delay calibration, the fusion principles are developed to get the improved and corrected gesture recognition. The gesture recognition and scenario experiments are carried out, and indicate the improvement of the proposed Multi-LeapMotion hand tracking system in tabletop object manipulation task for robotic demonstration.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11934009,11974187,and 12004187)the Natural Science Foundation of Jiangsu Province,China(Grant Nos.BK20161013 and BK20200724)。
文摘Contactless manipulation of multi-scale objects using the acoustic vortex(AV) tweezers offers tremendous perspectives in biomedical applications.However,it is still hindered by the weak acoustic radiation force(ARF) and torque(ART)around the vortex center.By introducing the elevation angle to the planar transducers of an N-element ring array,the weakfocused acoustic vortex(WFAV) composed of a main-AV and N paraxial-AVs is constructed to conduct a large-scale object manipulation.Different from the traditional focused AV(FAV) generated by a ring array of concave spherical transducers,a much larger focal region of the WFAV is generated by the main lobes of the planar transducers with the size inversely associated with the elevation angle.With the pressure simulation of the acoustic field,the capability of the rotational object driving in the focal plane for the WFAV is analyzed using the ARF and the ART exerted on an elastic ball based on acoustic scattering.With the experimental system built in water,the generation of the WFAV is verified by the scanning measurements of the acoustic field and the capability of object manipulation is also analyzed by the rotational trapping of floating particles in the focal plane.The favorable results demonstrate the feasibility of large-scale rotational manipulation of objects with a strengthened ART and a reduced acousto-thermal damage to biological tissues,showing a promising prospect for potential applications in clinical practice.
基金supported by“Regional Innovation Strategy (RIS)”through the National Research Foundation of Korea (NRF)funded by the Ministry of Education (MOE) (2021RIS-004).
文摘A concurrency control mechanism for collaborative work is akey element in a mixed reality environment. However, conventional lockingmechanisms restrict potential tasks or the support of non-owners, thusincreasing the working time because of waiting to avoid conflicts. Herein, wepropose an adaptive concurrency control approach that can reduce conflictsand work time. We classify shared object manipulation in mixed reality intodetailed goals and tasks. Then, we model the relationships among goal,task, and ownership. As the collaborative work progresses, the proposedsystem adapts the different concurrency control mechanisms of shared objectmanipulation according to the modeling of goal–task–ownership. With theproposed concurrency control scheme, users can hold shared objects andmove and rotate together in a mixed reality environment similar to realindustrial sites. Additionally, this system provides MS Hololens and Myosensors to recognize inputs from a user and provides results in a mixed realityenvironment. The proposed method is applied to install an air conditioneras a case study. Experimental results and user studies show that, comparedwith the conventional approach, the proposed method reduced the number ofconflicts, waiting time, and total working time.
文摘Holograms provide a characteristic manner to display and convey information, and have been improved to provide better user interactions Holographic interactions are important as they improve user interactions with virtual objects. Gesture interaction is a recent research topic, as it allows users to use their bare hands to directly interact with the hologram. However, it remains unclear whether real hand gestures are well suited for hologram applications. Therefore, we discuss the development process and implementation of three-dimensional object manipulation using natural hand gestures in a hologram. We describe the design and development process for hologram applications and its integration with real hand gesture interactions as initial findings. Experimental results from Nasa TLX form are discussed. Based on the findings, we actualize the user interactions in the hologram.
基金supported in part by the Brødrene Hartmanns(No.A36775)Thomas B.Thriges(No.7648-2106)+1 种基金Fabrikant Mads Clausens(No.2023-0210)EnergiFyn funds.
文摘This paper presents a learning-based control framework for fast(<1.5 s)and accurate manipulation of a flexible object,i.e.,whip targeting.The framework consists of a motion planner learned or optimized by an algorithm,Online Impedance Adaptation Control(OIAC),a sim2real mechanism,and a visual feedback component.The experimental results show that a soft actor-critic algorithm outperforms three Deep Reinforcement Learning(DRL),a nonlinear optimization,and a genetic algorithm in learning generalization of motion planning.It can greatly reduce average learning trials(to<20 of others)and maximize average rewards(to>3 times of others).Besides,motion tracking errors are greatly reduced to 13.29 and 22.36 of constant impedance control by the OIAC of the proposed framework.In addition,the trajectory similarity between simulated and physical whips is 89.09.The presented framework provides a new method integrating data-driven and physics-based algorithms for controlling fast and accurate arm manipulation of a flexible object.
文摘Deformable manipulation has attracted a lot of attention in the field of robotics,especially in medical applications.However,manipulating deformable objects faces various challenges,mainly including their complex dynamic properties and unpredictable nonlinear deformations.It is difficult to provide a basis for deformable object measurements without effective control methods that provide intelligent and accurate position control,and this research also provides a premise for deformable object measurements.To address these issues,this paper proposes an online iterative perception policy(IPP)method,which does not require large-scale deep network training.This method is able to perceive transformations through an iterative process,and achieve efficient and accurate control of deformable objects.Extensive experiments in the simulation environment and the real scene are conducted to validate the effectiveness and superiority of the proposed method,as well as to compare with advanced algorithms(linear–quadratic regulator(LQR),sliding mode control(SMC),model predictive control(MPC),and heuristic).The experimental results reveal that IPP outperforms other approaches in terms of convergence,stability,robustness and flexibility in both the simulation and real-world scenarios,regardless of textile properties or initial conditions.
基金funded by a grant from the Canadian Institutes of Health Research awarded to Dr. Meghann Lloyd and Dr. Mark Tremblay (IHD 94356)
文摘Purpose: The primary aim of this study was to develop an assessment of the fundamental, combined, and complex movement skills required to support childhood physical literacy. The secondary aim was to establish the feasibility, objectivity, and reliability evidence for the assessment.Methods: An expert advisory group recommended a course format for the assessment that would require children to complete a series of dynamic movement skills. Criterion-referenced skill performance and completion time were the recommended forms of evaluation. Children, 8–12 years of age, self-reported their age and gender and then completed the study assessments while attending local schools or day camps. Face validity was previously established through a Delphi expert(n = 19, 21% female) review process. Convergent validity was evaluated by age and gender associations with assessment performance. Inter-and intra-rater(n = 53, 34% female) objectivity and test–retest(n = 60, 47% female) reliability were assessed through repeated test administration.Results: Median total score was 21 of 28 points(range 5–28). Median completion time was 17 s. Total scores were feasible for all 995 children who self-reported age and gender. Total score did not differ between inside and outside environments(95% confidence interval(CI) of difference:-0.7 to 0.6;p = 0.91) or with/without footwear(95%CI of difference:-2.5 to 1.9; p = 0.77). Older age(p < 0.001, η2= 0.15) and male gender(p < 0.001, η2= 0.02)were associated with a higher total score. Inter-rater objectivity evidence was excellent(intraclass correlation coefficient(ICC) = 0.99) for completion time and substantial for skill score(ICC = 0.69) for 104 attempts by 53 children(34% female). Intra-rater objectivity was moderate(ICC = 0.52) for skill score and excellent for completion time(ICC = 0.99). Reliability was excellent for completion time over a short(2–4 days; ICC = 0.84) or long(8–14days; ICC = 0.82) interval. Skill score reliability was moderate(ICC = 0.46) over a short interval, and substantial(ICC = 0.74) over a long interval.Conclusion: The Canadian Agility and Movement Skill Assessment is a feasible measure of selected fundamental, complex and combined movement skills, which are an important building block for childhood physical literacy. Moderate-to-excellent objectivity was demonstrated for children 8–12 years of age. Test–retest reliability has been established over an interval of at least 1 week. The time and skill scores can be accurately estimated by 1 trained examiner.
基金the support from Optoseeker Biotechnology(Shenzhen)Co.,Ltd.to help build the OET system and provide Optobot 500 to carry out the experiment shown in supplementary Movie S4.National Key R&D Program of China(2023YFE0112400,2022YFA1207100,2024YFC3406900)National Natural Science Foundation of China(62103050,62473245,61933008)+6 种基金Beijing Municipal Natural Science Foundation(4242060,L246030)the Chongqing Municipal Natural Science Foundation(Grant No.2024NSCQJQX0192,CSTB2024NSCQ-JQX0034)the BIT Research and Innovation Promoting Project(Grant No.2023CX01002)Innovation Program of Shanghai Municipal Education Commission(2021-01-07-00-09-E0013)Shanghai Science and Technology plan project(23ZR1422300)Shenzhen Science and Technology Program(KJZD20240903101359020)Open Research Fund of Guangdong Provincial Key Laboratory of Advanced Biomaterials(Southern University of Science and Technology,Grant No.KLAB202404002).
文摘Automated parallel manipulation of multiple micro-objects with optoelectronic tweezers(OET)has brought significant research interests recently.However,the parallel manipulation of multiple objects in complex obstacle-dense microenvironment using OET technology based on negative dielectrophoresis(nDEP)remain a big technical challenge.In this work,we proposed an adaptive light pattern design strategy to achieve automated parallel OET manipulation of multiple micro-objects and navigate them through obstacles to target positions with high precision and no collision.We first developed a multi-micro-object parallel manipulation OET system,capable of simultaneous image processing and microparticles path planning.To overcome microparticle collisions caused by overlapping light patterns,we employed a novel adaptive light pattern design that can dynamically adjust the layout of overlapping light patterns according to surrounding environment,ensuring enough space for each microparticle and preventing unintended escapes from the OET trap.The efficacy of this approach has been verified through systematic simulations and experiments.Utilizing this strategy,multiple polystyrene microparticles were autonomously navigated through obstacles and microchannels to their intended destinations,demonstrating the strategy’s effectiveness and potential for automated parallel micromanipulation of multiple microparticles in complex and confined microenvironments.
文摘A view in object oriented databases corresponds to virtual schemawith restructured generalization and decomposition hierarchies. Numbers of viewcreation methodologies have been proposed. A major drawback of existing method-ologies is that they do not maintain the closure property. That is, the result of aquery does not have the same semantics as embodied in the object oriented datamodel. Therefore, this paper presents a view creation methodology that derives aclass in response to a user's query, integrates derived class in global schema (i.e.,considers the problem of classes moving in class hierarchy) and selects the requiredclasses from global schema to create the view for user's query. Novel idea of viewcreation includes: (a) an object algebra for class derivation and customization (wherethe derived classes in terms of object instances and procedure/methods are studied),(b) maintenance of closure property, and (c) classification algorithm which providesmechanism to deal with the problem of a class moving in a class hierarchy.
基金supported by the Discovery Grant(RGPIN-2018-05991)Collaborative Research and Training Experience Program Grant(555425-2021)the Natural Sciences and Engineering Research Council of Canada.
文摘This review paper presents a comprehensive evaluation and forward-looking perspective on the underexplored topic of servicing target objects using spacecraft swarms.Such targets can be known or unknown,cooperative or uncooperative,and pose significant challenges in modern space operations due to their inherent complexity and unpredictability.Successfully servicing space objects is vital for active debris removal and broader on-orbit servicing tasks such as satellite maintenance,repair,refueling,orbital assembly,and construction.Significant effort has been invested in the literature to explore the servicing of targets using a single spacecraft.Given its advantages and benefits,this paper expands the discussion to encompass a swarm approach to the problem.This review covers various single-spacecraft approaches and presents a critical examination of the existing,although limited,body of work dedicated to servicing orbital objects using multiple spacecraft.The focus is also broadened to include some influential studies concerning the characterization,capture,and manipulation of physical objects by general multiagent systems,a subject with significant parallels to the core interest of this manuscript.Furthermore,this article also delves into the realm of simultaneous localization and mapping,highlighting its application within close-proximity operations in space,especially when dealing with unknown uncooperative targets.Special attention is paid to the benefits that this field can receive from distributed multiagent architectures.Finally,an exploration of the promising field of swarm robotics is presented,with an emphasis on its potential to revolutionize the servicing of orbital target objects.Concurrently,a survey of general research directly engaging swarms in the orbital context is conducted.This review aims to bridge the knowledge gap and stimulate further research in the underexplored domain of servicing space targets with spacecraft swarms.
基金partially supported by the Shenzhen Science and Technology Program(grant no.RCYX20200714114736115)Shenzhen Institute of AI and Robotics for Society(grant no.AC01202101112).
文摘Telekinesis,as commonly portrayed in science fiction literature and cinema,is a super power wherein users control and manipulate objects absent in physical interaction.In real world,enhancing human–robot interaction needs the synthesis of human intuitive processes with robotic arm.This paper introduces a robotic teleoperation system achieving the essence of telekinetic operations,combining the profound capabilities of augmented reality(AR)with the robotic arm operations.Utilizing AR,the proposed methodology offers operators with a visual feedback,facilitating a level of control surpassing the capacities of natural interfaces.By using AR-driven visual recognition,this system achieves operations in a virtual environment,subsequently actualized in the real world through the robotic arm.Through multiple experiments,we found that the system has a small margin of error in telekinesis operations,meeting the needs of remote operation.Furthermore,our system can operate on objects in the real world.These experiments underscore the capability of the remote control system to assist humans in accomplishing a wider range of tasks through the integration of AR and robotic arms,providing a natural human–robot interaction approach.
基金supported by the Human Frontier Science Program(RGP0002/2017)the BrØrene Hartmanns Fund(A36775)the Thomas B.Thriges Fund(7648-2106).
文摘Variable Impedance control allows robots and humans to safely and efficiently interact with unknown external environments.This tutorial introduces online impedance adaptation control(OIAC)for variable compliant joint motions in a range of control tasks:rapid(<1 s)movement control(i.e.,whipping to hit),arm and finger impedance quantification,multifunctional exoskeleton control,and robot-inspired human arm control hypothesis.The OIAC has been introduced as a feedback control,which can be integrated into a feedforward control,e.g.,learned by data-driven methods.This integration facilitates the understanding of human and robot arm control,closing a research loop between biomechanics and robotics.It shows not only a research way from biomechanics to robotics,but also another reserved one.This tutorial aims at presenting research examples and Python codes for advancing the understanding of variable impedance adaptation in human and robot motor control.It contributes to the state-of-the-art by providing an online impedance adaptation controller for wearable robots(i.e.,exoskeletons)which can be used in robotic and biomechanical applications.
