The rapid advancement of Industry 4.0 has revolutionized manufacturing,shifting production from centralized control to decentralized,intelligent systems.Smart factories are now expected to achieve high adaptability an...The rapid advancement of Industry 4.0 has revolutionized manufacturing,shifting production from centralized control to decentralized,intelligent systems.Smart factories are now expected to achieve high adaptability and resource efficiency,particularly in mass customization scenarios where production schedules must accommodate dynamic and personalized demands.To address the challenges of dynamic task allocation,uncertainty,and realtime decision-making,this paper proposes Pathfinder,a deep reinforcement learning-based scheduling framework.Pathfinder models scheduling data through three key matrices:execution time(the time required for a job to complete),completion time(the actual time at which a job is finished),and efficiency(the performance of executing a single job).By leveraging neural networks,Pathfinder extracts essential features from these matrices,enabling intelligent decision-making in dynamic production environments.Unlike traditional approaches with fixed scheduling rules,Pathfinder dynamically selects from ten diverse scheduling rules,optimizing decisions based on real-time environmental conditions.To further enhance scheduling efficiency,a specialized reward function is designed to support dynamic task allocation and real-time adjustments.This function helps Pathfinder continuously refine its scheduling strategy,improving machine utilization and minimizing job completion times.Through reinforcement learning,Pathfinder adapts to evolving production demands,ensuring robust performance in real-world applications.Experimental results demonstrate that Pathfinder outperforms traditional scheduling approaches,offering improved coordination and efficiency in smart factories.By integrating deep reinforcement learning,adaptable scheduling strategies,and an innovative reward function,Pathfinder provides an effective solution to the growing challenges of multi-robot job scheduling in mass customization environments.展开更多
This survey presents a comprehensive review of vari-ous methods and algorithms related to passing-through control of multi-robot systems in cluttered environments.Numerous studies have investigated this area,and we id...This survey presents a comprehensive review of vari-ous methods and algorithms related to passing-through control of multi-robot systems in cluttered environments.Numerous studies have investigated this area,and we identify several avenues for enhancing existing methods.This survey describes some models of robots and commonly considered control objec-tives,followed by an in-depth analysis of four types of algo-rithms that can be employed for passing-through control:leader-follower formation control,multi-robot trajectory planning,con-trol-based methods,and virtual tube planning and control.Fur-thermore,we conduct a comparative analysis of these tech-niques and provide some subjective and general evaluations.展开更多
As a cross-cutting field between ocean development and multi-robot system(MRS),the underwater multi-robot system(UMRS)has gained increasing attention from researchers and engineers in recent decades.In this paper,we p...As a cross-cutting field between ocean development and multi-robot system(MRS),the underwater multi-robot system(UMRS)has gained increasing attention from researchers and engineers in recent decades.In this paper,we present a comprehensive survey of cooperation issues,one of the key components of UMRS,from the perspective of the emergence of new functions.More specifically,we categorize the cooperation in terms of task-space,motion-space,measurement-space,as well as their combination.Further,we analyze the architecture of UMRS from three aspects,i.e.,the performance of the individual underwater robot,the new functions of underwater robots,and the technical approaches of MRS.To conclude,we have discussed related promising directions for future research.This survey provides valuable insight into the reasonable utilization of UMRS to attain diverse underwater tasks in complex ocean application scenarios.展开更多
Nowadays, robots generally have a variety of capabilities, which often form a coalition replacing human to work in dangerous environment, such as rescue, exploration, etc. In these operating conditions, the energy sup...Nowadays, robots generally have a variety of capabilities, which often form a coalition replacing human to work in dangerous environment, such as rescue, exploration, etc. In these operating conditions, the energy supply of robots usually cannot be guaranteed. If the energy resources of some robots are consumed too fast, the number of the future tasks of the coalition will be affected. This paper will develop a novel task allocation method based on Gini coefficient to make full use of limited energy resources of multi-robot system to maximize the number of tasks. At the same time, considering resources consumption,we incorporate the market-based allocation mechanism into our Gini coefficient-based method and propose a hybrid method,which can flexibly optimize the task completion number and the resource consumption according to the application contexts.Experiments show that the multi-robot system with limited energy resources can accomplish more tasks by the proposed Gini coefficient-based method, and the hybrid method can be dynamically adaptive to changes of the work environment and realize the dual optimization goals.展开更多
A new coordination scheme for multi-robot systems is proposed. A state space model of the multi- robot system is defined and constructed in which the system＇s initial and goal states are included along with the task ...A new coordination scheme for multi-robot systems is proposed. A state space model of the multi- robot system is defined and constructed in which the system＇s initial and goal states are included along with the task definition and the system＇s internal and external constraints. Task accomplishment is considered a transition of the system state in its state space （SS） under the system＇s constraints. Therefore, if there exists a connectable path within reachable area of the SS from the initial state to the goal state, the task is realizable. The optimal strategy for the task realization under constraints is investigated and reached by searching for the optimal state transition trajectory of the robot system in the SS. Moreover, if there is no connectable path, which means the task cannot be performed Successfully, the task could be transformed to be realizable by making the initial state and the goal state connectable and finding a path connecting them in the system＇s SS. This might be done via adjusting the system＇s configuration and/or task constraints. Experiments of multi-robot formation control with obstacles in the environment are conducted and simulation results show the validity of the proposed method.展开更多
Analysis and design techniques for cooperative flocking of nonholonomic multi-robot systems with connectivity maintenance on directed graphs are presented. First, a set of bounded and smoothly distributed control prot...Analysis and design techniques for cooperative flocking of nonholonomic multi-robot systems with connectivity maintenance on directed graphs are presented. First, a set of bounded and smoothly distributed control protocols are devised via carefully designing a class of bounded artificial potential fields （APF） which could guarantee the connectivity maintenance, col ision avoidance and distance stabilization simultaneously during the system evolution. The connectivity of the underlying network can be preserved, and the desired stable flocking behavior can be achieved provided that the initial communication topology is strongly connected rather than undirected or balanced, which relaxes the constraints for group topology and extends the previous work to more generalized directed graphs. Furthermore, the proposed control algorithm is extended to solve the flocking problem with a virtual leader. In this case, it is shown that al robots can asymptotically move with the desired velocity and orientation even if there is only one informed robot in the team. Finally, nontrivial simulations and experiments are conducted to verify the effectiveness of the proposed algorithm.展开更多
This paper proposes a new coordination method for multi-robot system.The state space for a multi-robot system is constructed according to the task requirements and system characteristics.Reachable statefor the system ...This paper proposes a new coordination method for multi-robot system.The state space for a multi-robot system is constructed according to the task requirements and system characteristics.Reachable statefor the system is constrained by the system s internal and external constraints,under which the task isexecutable if there exists a state transition trajectory from the initial to the goal state in its state space.Ifthe task is realizable,the feasible or the optimal strategy for task execution could then be investigated inthe state space.Otherwise,the task could be modified to be realizable via adjusting system s configura-tions and/or task constraints,which provides critical guidance for system reconstructions.This con-tributes to the designing and planning of the robotic tasks.Experiments of multi-robot formation movementare conducted to show the validity of the proposed method.展开更多
This paper described a new method to plan out welding paths for multiple robots in virtual manufacturing environment. We first distribute welding tasks and priority for multi robots, and then apply corresponding behav...This paper described a new method to plan out welding paths for multiple robots in virtual manufacturing environment. We first distribute welding tasks and priority for multi robots, and then apply corresponding behavior rules to help to plan out welding paths for robots collision free, which is a base fixed problem. Finally, we testify the algorithm to be practical in virtual environment, and output robot programs to direct production process. This new way will help us to find a new development method for multiple robots path planning.展开更多
In an Internet based multi-operator and multi-robot system (IMOMR), operators have to work collaboratively to overcome the constraints of space and time. Inherently, the activities among them can be defined as a compu...In an Internet based multi-operator and multi-robot system (IMOMR), operators have to work collaboratively to overcome the constraints of space and time. Inherently, the activities among them can be defined as a computer-supported cooperative work (CSCW). As a practical application of CSCW, a collaborative task planning system (CTPS) for IMOMR is proposed in this paper on the basis of Petri nets. Its definition, components design, and concrete implementation are given in detail, respectively. As a result, a clear collaboration mechanism of multiple operators in an IMOMR is obtained to guarantee their task planning.展开更多
This paper introduces a new control strategy for heterogeneous multi-robots systems dedicated to industrial logistic setups. This control strategy is based on both distributed intelligence and machine learning and inv...This paper introduces a new control strategy for heterogeneous multi-robots systems dedicated to industrial logistic setups. This control strategy is based on both distributed intelligence and machine learning and involves three parts: the rigid formation controller, the perception system and the path planner. Our controller is event-based and thus its control-coordination strategy can be self-adaptive and applied to real dynamic environment. During the navigating process, the multi-robots system derives the environment model, performs the path planning process that guaranties both the transportation constraints and the obstacle avoidance. For the validation, both simulation and real robot experiments are performed. The results show that the developed control strategy can be well used for realistic logistics applications.展开更多
A cooperative multi-robot system (CMRS) modeling method called fuzzy timed agent based Petri nets (FTAPN) is proposed in this paper, which has been extended from fuzzy timed object-oriented Petri net (FTOPN). The prop...A cooperative multi-robot system (CMRS) modeling method called fuzzy timed agent based Petri nets (FTAPN) is proposed in this paper, which has been extended from fuzzy timed object-oriented Petri net (FTOPN). The proposed FTAPN can be used to model and illustrate both the structural and dynamic aspects of CMRS, which is a typical multi-agent system (MAS). At the same time, supervised learning is supported in FTAPN. As a special type of high-level object, agent is introduced into FTAPN, which is used as a common modeling object in its model. The proposed FTAPN can not only be used to model CMRS and represent system aging effect, but also be refined into the object-oriented implementation easily. At the same time, it can also be regarded as a conceptual and practical artificial intelligence (AI) tool for multi-agent systems (MAS) into the mainstream practice of the software development.展开更多
Multi-robot coordinated towing system is an under-constrained system.The dynamic response of the towing system can not be fully controlled since the rope can only provide a unidirectional constraint force to the suspe...Multi-robot coordinated towing system is an under-constrained system.The dynamic response of the towing system can not be fully controlled since the rope can only provide a unidirectional constraint force to the suspended object.Based on the kinematics of the multi-robot coordinated towing system with fixed-base,the Newton-Euler equations and Udwadia-Kalaba equations were used to establish the dynamics of the towing system.To obtain the motion trajectories with high stability and strong control,the motion trajectories of the towing system were optimized.During the towing,the transition from the relaxation state to the tension state of the rope was treated as a collision between the suspended object and the robot end.The trajectories of the towing system in terms of a single-variable and multiple-variable were solved,respectively.The simulation shows that the optimized trajectories are closer to reality and truly reflect the constraints of the ropes on the suspended object.The research results provide a basis for trajectory planning and control of the towing system.展开更多
Cranes used at sea have some shortcomings in terms of flexibility,efficiency,and safety.Therefore,a floating multi-robot coordinated towing system is planned to fulfill the offshore towing requirements.It is difficult...Cranes used at sea have some shortcomings in terms of flexibility,efficiency,and safety.Therefore,a floating multi-robot coordinated towing system is planned to fulfill the offshore towing requirements.It is difficult to study the stability of a floating multi-robot coordinated towing system by ancient strategies.First,the minimum tension of the rope and the minimum singular value of the stiffness matrix were separately used to analyze the load stability.The advantages and disadvantages of the two methods were discussed.Then,the two stability analysis methods were normalized and weighted to obtain the method based on minimum tension and minimum singular to comprehensively analyze the stability of the load.Finally,the effect of different weighting coefficients on the load stability was analyzed,which led to a reasonable weighting coefficient to evaluate the load stability by comparing with a single analysis method.The research results provide a basis for the motion planning and coordinated control of the towing system.展开更多
For the process of multi-robot collaboration to lift the same lifted object by flexible cables,the existing collision detection algorithm of cables between the environmental obstacles has the problem of misjudgment an...For the process of multi-robot collaboration to lift the same lifted object by flexible cables,the existing collision detection algorithm of cables between the environmental obstacles has the problem of misjudgment and omission.In this work,the collision detection of cable vector was studied,and the purpose of collision detection was realized by algorithm.Considering the characteristics of cables themselves,based on oriented bounding box theory,the cable optimization model and environmental obstacle model were established,and a new basic geometric collision detection model was proposed.Then a fast cable vector collision detection algorithm and an optimization principle were proposed.Finally,the rationality of the cable collision detection model and the effectiveness of the proposed algorithm were verified by simulation.Simulation results show that the proposed method can meet the requirements of the fast detection and the accuracy in complex virtual environment.The results lay a foundation for obstacle avoidance motion planning of system.展开更多
This paper studies the problem of formation-containment for multi-robot systems with stochastic sampling.First,a stochastic sampling control protocol is proposed,in which information exchanging among robots only occur...This paper studies the problem of formation-containment for multi-robot systems with stochastic sampling.First,a stochastic sampling control protocol is proposed,in which information exchanging among robots only occurred at the sampling time and two different sampling periods randomly switch.Thus,both energy and controller updating frequencies can be reduced.Also,the protocol can be applied to the situation where the sampling period varies stochastically.Second,sufficient conditions guaranteeing mean square formation-containment are derived.Under stochastic sampling mechanism,the leaders reach a geometric formation shape and the followers are in the geometric formation shape formed by the leaders.Finally,an example is shown to demonstrate the results.展开更多
The problem of allocating a number of exploration tasks to a team of mobile robots in dynamic environments was studied. The team mission is to visit several distributed targets. The path cost of target is proportional...The problem of allocating a number of exploration tasks to a team of mobile robots in dynamic environments was studied. The team mission is to visit several distributed targets. The path cost of target is proportional to the distance that a robot has to move to visit the target. The team objective is to minimize the average path cost of target over all targets. Finding an optimal allocation is strongly NP-hard. The proposed algorithm can produce a near-optimal solution to it. The allocation can be cast in terms of a multi-round single-item auction by which robots bid on targets. In each auction round, one target is assigned to a robot that produces the lowest path cost of the target. The allocated targets form a forest where each tree corresponds a robot’s exploring targets set. Each robot constructs an exploring path through depth-first search in its target tree. The time complexity of the proposed algorithm is polynomial. Simulation experiments show that the allocating method is valid.展开更多
Swarming behaviors play an eminent role in both biological and engineering research, and show great potential applications in many emerging fields. Traditional swarming models still lack integrity, uniformity, and sta...Swarming behaviors play an eminent role in both biological and engineering research, and show great potential applications in many emerging fields. Traditional swarming models still lack integrity, uniformity, and stability in swarm forming processes,resulting in fragmentation and void phenomena. Inspired by the shepherding behaviors observed in nature, we propose an integrated negotiation-control scheme for distributed swarm control of massive robots. The core idea of this scheme is that the robots at the boundary of the group herd the internal robots to form an equilibrium swarm. For this purpose, we introduce a concept of virtual group center towards which boundary robots herd internal robots. Then, a distributed negotiation mechanism is designed to allow each robot to negotiate the virtual group center only through local interactions with its neighbors. After that, we propose a shepherding-inspired swarm control law to drive a group of robots to form an integrated, uniform, and stable configuration from any initial states. Both numerical and flight simulations are presented to verify the effectiveness of our proposed swarm control scheme.展开更多
Given a collection of parameterized multi-robot controllers associated with individual behaviors designed for particular tasks,this paper considers the problem of how to sequence and instantiate the behaviors for the ...Given a collection of parameterized multi-robot controllers associated with individual behaviors designed for particular tasks,this paper considers the problem of how to sequence and instantiate the behaviors for the purpose of completing a more complex,overarching mission.In addition,uncertainties about the environment or even the mission specifcations may require the robots to learn,in a cooperative manner,how best to sequence the behaviors.In this paper,we approach this problem by using reinforcement learning to approximate the solution to the computationally intractable sequencing problem,combined with an online gradient descent approach to selecting the individual behavior parameters,while the transitions among behaviors are triggered automatically when the behaviors have reached a desired performance level relative to a task performance cost.To illustrate the efectiveness of the proposed method,it is implemented on a team of diferential-drive robots for solving two diferent missions,namely,convoy protection and object manipulation.展开更多
基金supported by National Natural Science Foundation of China under Grant No.62372110Fujian Provincial Natural Science of Foundation under Grants 2023J02008,2024H0009.
文摘The rapid advancement of Industry 4.0 has revolutionized manufacturing,shifting production from centralized control to decentralized,intelligent systems.Smart factories are now expected to achieve high adaptability and resource efficiency,particularly in mass customization scenarios where production schedules must accommodate dynamic and personalized demands.To address the challenges of dynamic task allocation,uncertainty,and realtime decision-making,this paper proposes Pathfinder,a deep reinforcement learning-based scheduling framework.Pathfinder models scheduling data through three key matrices:execution time(the time required for a job to complete),completion time(the actual time at which a job is finished),and efficiency(the performance of executing a single job).By leveraging neural networks,Pathfinder extracts essential features from these matrices,enabling intelligent decision-making in dynamic production environments.Unlike traditional approaches with fixed scheduling rules,Pathfinder dynamically selects from ten diverse scheduling rules,optimizing decisions based on real-time environmental conditions.To further enhance scheduling efficiency,a specialized reward function is designed to support dynamic task allocation and real-time adjustments.This function helps Pathfinder continuously refine its scheduling strategy,improving machine utilization and minimizing job completion times.Through reinforcement learning,Pathfinder adapts to evolving production demands,ensuring robust performance in real-world applications.Experimental results demonstrate that Pathfinder outperforms traditional scheduling approaches,offering improved coordination and efficiency in smart factories.By integrating deep reinforcement learning,adaptable scheduling strategies,and an innovative reward function,Pathfinder provides an effective solution to the growing challenges of multi-robot job scheduling in mass customization environments.
文摘This survey presents a comprehensive review of vari-ous methods and algorithms related to passing-through control of multi-robot systems in cluttered environments.Numerous studies have investigated this area,and we identify several avenues for enhancing existing methods.This survey describes some models of robots and commonly considered control objec-tives,followed by an in-depth analysis of four types of algo-rithms that can be employed for passing-through control:leader-follower formation control,multi-robot trajectory planning,con-trol-based methods,and virtual tube planning and control.Fur-thermore,we conduct a comparative analysis of these tech-niques and provide some subjective and general evaluations.
基金This work was supported in part by the National Natural Science Foundation of China(U1909206,61725305,61903007,62073196)in part by the S&T Program of Hebei(F2020203037).
文摘As a cross-cutting field between ocean development and multi-robot system(MRS),the underwater multi-robot system(UMRS)has gained increasing attention from researchers and engineers in recent decades.In this paper,we present a comprehensive survey of cooperation issues,one of the key components of UMRS,from the perspective of the emergence of new functions.More specifically,we categorize the cooperation in terms of task-space,motion-space,measurement-space,as well as their combination.Further,we analyze the architecture of UMRS from three aspects,i.e.,the performance of the individual underwater robot,the new functions of underwater robots,and the technical approaches of MRS.To conclude,we have discussed related promising directions for future research.This survey provides valuable insight into the reasonable utilization of UMRS to attain diverse underwater tasks in complex ocean application scenarios.
基金supported by the National High Technology Research and Development Program of China(863 Program)(2015AA015403)the National Natural Science Foundation of China(61404069,61401185)the Project of Education Department of Liaoning Province(LJYL052)
文摘Nowadays, robots generally have a variety of capabilities, which often form a coalition replacing human to work in dangerous environment, such as rescue, exploration, etc. In these operating conditions, the energy supply of robots usually cannot be guaranteed. If the energy resources of some robots are consumed too fast, the number of the future tasks of the coalition will be affected. This paper will develop a novel task allocation method based on Gini coefficient to make full use of limited energy resources of multi-robot system to maximize the number of tasks. At the same time, considering resources consumption,we incorporate the market-based allocation mechanism into our Gini coefficient-based method and propose a hybrid method,which can flexibly optimize the task completion number and the resource consumption according to the application contexts.Experiments show that the multi-robot system with limited energy resources can accomplish more tasks by the proposed Gini coefficient-based method, and the hybrid method can be dynamically adaptive to changes of the work environment and realize the dual optimization goals.
基金the National Natural Science Foundation of China (60428303).
文摘A new coordination scheme for multi-robot systems is proposed. A state space model of the multi- robot system is defined and constructed in which the system＇s initial and goal states are included along with the task definition and the system＇s internal and external constraints. Task accomplishment is considered a transition of the system state in its state space （SS） under the system＇s constraints. Therefore, if there exists a connectable path within reachable area of the SS from the initial state to the goal state, the task is realizable. The optimal strategy for the task realization under constraints is investigated and reached by searching for the optimal state transition trajectory of the robot system in the SS. Moreover, if there is no connectable path, which means the task cannot be performed Successfully, the task could be transformed to be realizable by making the initial state and the goal state connectable and finding a path connecting them in the system＇s SS. This might be done via adjusting the system＇s configuration and/or task constraints. Experiments of multi-robot formation control with obstacles in the environment are conducted and simulation results show the validity of the proposed method.
基金supported by the National Natural Science Foundation of China(61175112)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(G61321002)+3 种基金the Projects of Major International(Regional)Joint Research Program(61120106010)the Beijing Education Committee Cooperation Building Foundationthe Program for Changjiang Scholars and Innovative Research Team in University(IRT1208)the ChangJiang Scholars Program and the Beijing Outstanding Ph.D.Program Mentor Grant(20131000704)
文摘Analysis and design techniques for cooperative flocking of nonholonomic multi-robot systems with connectivity maintenance on directed graphs are presented. First, a set of bounded and smoothly distributed control protocols are devised via carefully designing a class of bounded artificial potential fields （APF） which could guarantee the connectivity maintenance, col ision avoidance and distance stabilization simultaneously during the system evolution. The connectivity of the underlying network can be preserved, and the desired stable flocking behavior can be achieved provided that the initial communication topology is strongly connected rather than undirected or balanced, which relaxes the constraints for group topology and extends the previous work to more generalized directed graphs. Furthermore, the proposed control algorithm is extended to solve the flocking problem with a virtual leader. In this case, it is shown that al robots can asymptotically move with the desired velocity and orientation even if there is only one informed robot in the team. Finally, nontrivial simulations and experiments are conducted to verify the effectiveness of the proposed algorithm.
基金Supported by the National Natural Science Foundation for Distinguished Young Scholars Abroad (No. 60428303)
文摘This paper proposes a new coordination method for multi-robot system.The state space for a multi-robot system is constructed according to the task requirements and system characteristics.Reachable statefor the system is constrained by the system s internal and external constraints,under which the task isexecutable if there exists a state transition trajectory from the initial to the goal state in its state space.Ifthe task is realizable,the feasible or the optimal strategy for task execution could then be investigated inthe state space.Otherwise,the task could be modified to be realizable via adjusting system s configura-tions and/or task constraints,which provides critical guidance for system reconstructions.This con-tributes to the designing and planning of the robotic tasks.Experiments of multi-robot formation movementare conducted to show the validity of the proposed method.
基金Natural Science Foundation of China (No.5 98895 0 5 )
文摘This paper described a new method to plan out welding paths for multiple robots in virtual manufacturing environment. We first distribute welding tasks and priority for multi robots, and then apply corresponding behavior rules to help to plan out welding paths for robots collision free, which is a base fixed problem. Finally, we testify the algorithm to be practical in virtual environment, and output robot programs to direct production process. This new way will help us to find a new development method for multiple robots path planning.
文摘In an Internet based multi-operator and multi-robot system (IMOMR), operators have to work collaboratively to overcome the constraints of space and time. Inherently, the activities among them can be defined as a computer-supported cooperative work (CSCW). As a practical application of CSCW, a collaborative task planning system (CTPS) for IMOMR is proposed in this paper on the basis of Petri nets. Its definition, components design, and concrete implementation are given in detail, respectively. As a result, a clear collaboration mechanism of multiple operators in an IMOMR is obtained to guarantee their task planning.
文摘This paper introduces a new control strategy for heterogeneous multi-robots systems dedicated to industrial logistic setups. This control strategy is based on both distributed intelligence and machine learning and involves three parts: the rigid formation controller, the perception system and the path planner. Our controller is event-based and thus its control-coordination strategy can be self-adaptive and applied to real dynamic environment. During the navigating process, the multi-robots system derives the environment model, performs the path planning process that guaranties both the transportation constraints and the obstacle avoidance. For the validation, both simulation and real robot experiments are performed. The results show that the developed control strategy can be well used for realistic logistics applications.
文摘A cooperative multi-robot system (CMRS) modeling method called fuzzy timed agent based Petri nets (FTAPN) is proposed in this paper, which has been extended from fuzzy timed object-oriented Petri net (FTOPN). The proposed FTAPN can be used to model and illustrate both the structural and dynamic aspects of CMRS, which is a typical multi-agent system (MAS). At the same time, supervised learning is supported in FTAPN. As a special type of high-level object, agent is introduced into FTAPN, which is used as a common modeling object in its model. The proposed FTAPN can not only be used to model CMRS and represent system aging effect, but also be refined into the object-oriented implementation easily. At the same time, it can also be regarded as a conceptual and practical artificial intelligence (AI) tool for multi-agent systems (MAS) into the mainstream practice of the software development.
基金the National Natural Science Foundation of China(No.51965032)the Natural Science Foundation of Gansu Province of China(No.22JR5RA319)+1 种基金the Science and Technology Foundation of Gansu Province of China(No.21YF5WA060)the Excellent Doctoral Student Foundation of Gansu Province of China(No.23JRRA842)。
文摘Multi-robot coordinated towing system is an under-constrained system.The dynamic response of the towing system can not be fully controlled since the rope can only provide a unidirectional constraint force to the suspended object.Based on the kinematics of the multi-robot coordinated towing system with fixed-base,the Newton-Euler equations and Udwadia-Kalaba equations were used to establish the dynamics of the towing system.To obtain the motion trajectories with high stability and strong control,the motion trajectories of the towing system were optimized.During the towing,the transition from the relaxation state to the tension state of the rope was treated as a collision between the suspended object and the robot end.The trajectories of the towing system in terms of a single-variable and multiple-variable were solved,respectively.The simulation shows that the optimized trajectories are closer to reality and truly reflect the constraints of the ropes on the suspended object.The research results provide a basis for trajectory planning and control of the towing system.
基金the National Natural Science Foundation of China(No.51965032)the Natural Science Foundation of Gansu Province(No.22JR5RA319)+1 种基金the Science and Technology Foundation of Gansu Province(No.21YF5WA060)the Excellent Doctoral Student Foundation of Gansu Province(No.23JRRA842)。
文摘Cranes used at sea have some shortcomings in terms of flexibility,efficiency,and safety.Therefore,a floating multi-robot coordinated towing system is planned to fulfill the offshore towing requirements.It is difficult to study the stability of a floating multi-robot coordinated towing system by ancient strategies.First,the minimum tension of the rope and the minimum singular value of the stiffness matrix were separately used to analyze the load stability.The advantages and disadvantages of the two methods were discussed.Then,the two stability analysis methods were normalized and weighted to obtain the method based on minimum tension and minimum singular to comprehensively analyze the stability of the load.Finally,the effect of different weighting coefficients on the load stability was analyzed,which led to a reasonable weighting coefficient to evaluate the load stability by comparing with a single analysis method.The research results provide a basis for the motion planning and coordinated control of the towing system.
基金the National Natural Science Foundation of China(Nos.51265021 and 51965032)the Gansu Provincial Department of Education:Excellent Graduate Student“Innovation Star"Project(No.2022CXZX-571)。
文摘For the process of multi-robot collaboration to lift the same lifted object by flexible cables,the existing collision detection algorithm of cables between the environmental obstacles has the problem of misjudgment and omission.In this work,the collision detection of cable vector was studied,and the purpose of collision detection was realized by algorithm.Considering the characteristics of cables themselves,based on oriented bounding box theory,the cable optimization model and environmental obstacle model were established,and a new basic geometric collision detection model was proposed.Then a fast cable vector collision detection algorithm and an optimization principle were proposed.Finally,the rationality of the cable collision detection model and the effectiveness of the proposed algorithm were verified by simulation.Simulation results show that the proposed method can meet the requirements of the fast detection and the accuracy in complex virtual environment.The results lay a foundation for obstacle avoidance motion planning of system.
基金supported by the National Natural Science Foundation of China(Grant No.61873318)the Frontier Research Funds of Applied Foundation of Wuhan(Grant No.2019010701011421)+1 种基金the National Defense Scienceof China(Grant No.JCKY2017207B005)the Program for HUST(Huazhong University of Science and Technology)Academic Frontier Youth Team(Grant No.2018QYTD07)。
文摘This paper studies the problem of formation-containment for multi-robot systems with stochastic sampling.First,a stochastic sampling control protocol is proposed,in which information exchanging among robots only occurred at the sampling time and two different sampling periods randomly switch.Thus,both energy and controller updating frequencies can be reduced.Also,the protocol can be applied to the situation where the sampling period varies stochastically.Second,sufficient conditions guaranteeing mean square formation-containment are derived.Under stochastic sampling mechanism,the leaders reach a geometric formation shape and the followers are in the geometric formation shape formed by the leaders.Finally,an example is shown to demonstrate the results.
基金Project(A1420060159) supported by the National Basic Research of China projects(60234030 60404021) supported bythe National Natural Science Foundation of China
文摘The problem of allocating a number of exploration tasks to a team of mobile robots in dynamic environments was studied. The team mission is to visit several distributed targets. The path cost of target is proportional to the distance that a robot has to move to visit the target. The team objective is to minimize the average path cost of target over all targets. Finding an optimal allocation is strongly NP-hard. The proposed algorithm can produce a near-optimal solution to it. The allocation can be cast in terms of a multi-round single-item auction by which robots bid on targets. In each auction round, one target is assigned to a robot that produces the lowest path cost of the target. The allocated targets form a forest where each tree corresponds a robot’s exploring targets set. Each robot constructs an exploring path through depth-first search in its target tree. The time complexity of the proposed algorithm is polynomial. Simulation experiments show that the allocating method is valid.
基金supported by the National Key R&D Program of China (Grant No. 2022YFB3305600)the National Natural Science Foundation of China (Grant Nos. 62103015 and 62141604)+1 种基金the China Postdoctoral Science Foundation (Grant No. 2023M740185)the Postdoctoral Fellows of Beihang “Zhuoyue” Program。
文摘Swarming behaviors play an eminent role in both biological and engineering research, and show great potential applications in many emerging fields. Traditional swarming models still lack integrity, uniformity, and stability in swarm forming processes,resulting in fragmentation and void phenomena. Inspired by the shepherding behaviors observed in nature, we propose an integrated negotiation-control scheme for distributed swarm control of massive robots. The core idea of this scheme is that the robots at the boundary of the group herd the internal robots to form an equilibrium swarm. For this purpose, we introduce a concept of virtual group center towards which boundary robots herd internal robots. Then, a distributed negotiation mechanism is designed to allow each robot to negotiate the virtual group center only through local interactions with its neighbors. After that, we propose a shepherding-inspired swarm control law to drive a group of robots to form an integrated, uniform, and stable configuration from any initial states. Both numerical and flight simulations are presented to verify the effectiveness of our proposed swarm control scheme.
基金This work was supported by the Army Research Lab(No.DCIST CRA W911NF-17-2-0181).
文摘Given a collection of parameterized multi-robot controllers associated with individual behaviors designed for particular tasks,this paper considers the problem of how to sequence and instantiate the behaviors for the purpose of completing a more complex,overarching mission.In addition,uncertainties about the environment or even the mission specifcations may require the robots to learn,in a cooperative manner,how best to sequence the behaviors.In this paper,we approach this problem by using reinforcement learning to approximate the solution to the computationally intractable sequencing problem,combined with an online gradient descent approach to selecting the individual behavior parameters,while the transitions among behaviors are triggered automatically when the behaviors have reached a desired performance level relative to a task performance cost.To illustrate the efectiveness of the proposed method,it is implemented on a team of diferential-drive robots for solving two diferent missions,namely,convoy protection and object manipulation.
