It is challenging for underwater vehicle-manipulator systems(UVMSs)to operate autonomously in unstructured underwater environments.Relying solely on teleoperation for both underwater vehicle(UV)and underwater manipula...It is challenging for underwater vehicle-manipulator systems(UVMSs)to operate autonomously in unstructured underwater environments.Relying solely on teleoperation for both underwater vehicle(UV)and underwater manipulator(UM)imposes a considerable cognitive and physical load on the operator.In this paper,we propose a unifed shared control(USC)architecture for the UVMS,integrating divisible shared control(DSC)and interactive shared control(ISC)to alleviate the operator's workload.By applying task priority based on DSC,we divide the whole-body task into constraints,operation,and posture optimization subtasks.The robot autonomously avoids self-collisions and adjusts its posture according to the user's visual preferences.IsC incorporates haptic feedback to enhance human-robot collaboration,seamlessly integrating it into the operation task via a whole-body controller for the UVMS.Simulations and pool experiments are conducted to verify the feasibility of the method.Compared to manual control(MC),the proposed method reduces completion time by 17.50%,operator input length by 25.00%,and cognitive load by 35.53%in the simulations,with corresponding reductions of 22.73%,40.00%,and 29.91%in the pool experiments.Subjective measurements demonstrate the reduction in operator workload with the proposed method.展开更多
μC/OS-Ⅱ is an open source real-time kernel adopting priority preemptive schedule strategy. Aiming at the problem of μC/OS-Ⅱ failing to support homology priority tasks scheduling, an approach for solution is propos...μC/OS-Ⅱ is an open source real-time kernel adopting priority preemptive schedule strategy. Aiming at the problem of μC/OS-Ⅱ failing to support homology priority tasks scheduling, an approach for solution is proposed. The basic idea is adding round-robin scheduling strategy in its original scheduler in order to schedule homology priority tasks through time slice roundrobin. Implementation approach is given in detail. Firstly, the Task Control Block （TCB） is extended. And then, a new priority index table is created, in which each index pointer points to a set of homology priority tasks. Eventually, on the basis of reconstructing μC/OS-Ⅱ real-time kernel, task scheduling module is rewritten. Otherwise, schedulability of homology task supported by modified kernel had been analyzed, and deadline formula of created homology tasks is given. By theoretical analysis and experiment verification, the modified kernel can support homology priority tasks scheduling, meanwhile, it also remains preemptive property of original μC/OS-Ⅱ.展开更多
This paper presents a singularity robust path planning for space manipulator to achieve base （satellite） attitude adjustment and end-effector task. The base attitude adjustment by the movement of manipulator will sa...This paper presents a singularity robust path planning for space manipulator to achieve base （satellite） attitude adjustment and end-effector task. The base attitude adjustment by the movement of manipulator will save propellant compared with conventional attitude control system. A task-priority reaction null-space control method is applied to achieve the primary task of adjusting attitude and secondary task of accomplishing end-effector task. Furthermore, the algorithm singularity is eliminated in the proposed algorithm compared with conventional reaction null-space algorithm. And the singular value filtering decomposition is introduced to dispose the dynamic singularity, the unit quaternion is also introduced to overcome representation singularity. Hence, a singularity robust path planning algorithm of space robot for base attitude adjustment is derived. A real time simulation system of the space robot under Linux/RTAl （realtime application interface） is developed to verify and test the feasibility and reliability of the method. The experimental results demonstrate the feasibility of online base attitude adjustment of space robot by the proposed algorithm.展开更多
基金Project supported by the National Natural Science Foundation of China(No.52071292)。
文摘It is challenging for underwater vehicle-manipulator systems(UVMSs)to operate autonomously in unstructured underwater environments.Relying solely on teleoperation for both underwater vehicle(UV)and underwater manipulator(UM)imposes a considerable cognitive and physical load on the operator.In this paper,we propose a unifed shared control(USC)architecture for the UVMS,integrating divisible shared control(DSC)and interactive shared control(ISC)to alleviate the operator's workload.By applying task priority based on DSC,we divide the whole-body task into constraints,operation,and posture optimization subtasks.The robot autonomously avoids self-collisions and adjusts its posture according to the user's visual preferences.IsC incorporates haptic feedback to enhance human-robot collaboration,seamlessly integrating it into the operation task via a whole-body controller for the UVMS.Simulations and pool experiments are conducted to verify the feasibility of the method.Compared to manual control(MC),the proposed method reduces completion time by 17.50%,operator input length by 25.00%,and cognitive load by 35.53%in the simulations,with corresponding reductions of 22.73%,40.00%,and 29.91%in the pool experiments.Subjective measurements demonstrate the reduction in operator workload with the proposed method.
基金Supported by the "Chunhui" Plan of Ministry of Education of China (Z2005-2-11013)
文摘μC/OS-Ⅱ is an open source real-time kernel adopting priority preemptive schedule strategy. Aiming at the problem of μC/OS-Ⅱ failing to support homology priority tasks scheduling, an approach for solution is proposed. The basic idea is adding round-robin scheduling strategy in its original scheduler in order to schedule homology priority tasks through time slice roundrobin. Implementation approach is given in detail. Firstly, the Task Control Block （TCB） is extended. And then, a new priority index table is created, in which each index pointer points to a set of homology priority tasks. Eventually, on the basis of reconstructing μC/OS-Ⅱ real-time kernel, task scheduling module is rewritten. Otherwise, schedulability of homology task supported by modified kernel had been analyzed, and deadline formula of created homology tasks is given. By theoretical analysis and experiment verification, the modified kernel can support homology priority tasks scheduling, meanwhile, it also remains preemptive property of original μC/OS-Ⅱ.
基金supported by National Program on Key Basic Research Project(973 Program,No.2013CB733103)the Program for New Century Excellent Talents in University(No.NCET-10-0058)
文摘This paper presents a singularity robust path planning for space manipulator to achieve base （satellite） attitude adjustment and end-effector task. The base attitude adjustment by the movement of manipulator will save propellant compared with conventional attitude control system. A task-priority reaction null-space control method is applied to achieve the primary task of adjusting attitude and secondary task of accomplishing end-effector task. Furthermore, the algorithm singularity is eliminated in the proposed algorithm compared with conventional reaction null-space algorithm. And the singular value filtering decomposition is introduced to dispose the dynamic singularity, the unit quaternion is also introduced to overcome representation singularity. Hence, a singularity robust path planning algorithm of space robot for base attitude adjustment is derived. A real time simulation system of the space robot under Linux/RTAl （realtime application interface） is developed to verify and test the feasibility and reliability of the method. The experimental results demonstrate the feasibility of online base attitude adjustment of space robot by the proposed algorithm.
