This article proposes a distributed passivity-based bilateral teleoperation control for optimizing the velocity/force manipulability of the coordinated remote redundant manipulators during the task execution. Following the leader–follower paradigm, the control connects a local haptic device with a leader remote manipulator and coordinates all the leader and follower remote manipulators. The approach is novel in reconciling the potential conflicts between the pose synchronization task and the manipulability optimization task for the remote manipulators by two-layer auxiliary systems. The first layer decouples the pose synchronization constraints into separable position and orientation constraints, and the second layer optimizes the manipulability under the position and orientation constraints. The approach is robust by designing smooth controls for the manipulators without knowing their dynamic parameters. Finally, the control renders the bilateral teleoperator output strictly passive for stable physical interactions with the human user and the environment. Comparative experiments verify the effectiveness of the proposed control in the presence of time-varying communication delays.

This article presents a passivity-based shared control for a multirobot teleoperation system to perform extravehicular assembly tasks. At the remote site, an eye-in-hand camera is integrated with three manipulators that cooperatively drive a customized tool. A haptic device at the local site allows a human operator to intervene when necessary via bilateral teleoperation. To enable intuitive user control, a homography-based method seamlessly integrates visual servoing and operator input to guide the remote camera. To accommodate different peg geometries and enable adaptive tool actuation, a partial pose synchronization method decouples roll from the other pose dimensions. It allows each manipulator to independently actuate a gripper by rotating its end-effector frame around the roll axis, without interfering with cooperative motion in position, pitch, and yaw. In addition, to minimize undesired internal forces, we formulate and solve a passivity-constrained interaction wrench optimization problem that enhances stability. The proposed control ensures smooth transitions between autonomous and teleoperated modes, supporting flexible human intervention. Theoretical analysis and experimental validation confirm the system’s stability and effectiveness in achieving precise, robust, and responsive multirobot teleoperation for complex space assembly tasks.

A remote multirobot system (RMRS) outfitted with wireless sensors for large-scale data collection may need to be tele-driven by several human users simultaneously. The long distances between the users’ local robots and the RMRS can inject time-varying delays in their communications. This article enables such multiuser teleoperation of an RMRS through a control strategy that robustly synchronizes an RMRS with tree topology and proximity-limited one-hop communications among its robots, enables multiple users to tele-guide the RMRS and to feel the actions of the other users over time-delayed communications between the users’ local robots and the RMRS, and contains the RMRS to the stationary convex hull spanned by the local robots of all users in the steady state. A control design constrained by the connectivity of the RMRS and by the passivity of the teleoperator guarantees effective coordination, safe teleoperation, and steady-state containment. The design is a dynamic feedforward–feedback passivation strategy facilitated by a suitable decomposition of the teleoperator into interconnected subsystems. The analysis of the storage functions, and thus of the input–output relations, of all subsystems and their interconnections proves the properties of the design. Comparative experiments in a teleoperation testbed with four local and ten remote robots validate its practical efficacy.

A remote team of robots may be teleoperated by multiple users to explore unstructured environments and to tackle unforeseen emergencies therein. During a large-scale environmental search, each user may visually observe a unique hazard endangering the remote robot connected to their local robot. Therefore, each user may want to tele-drive the remote robot team to a location different than the target locations of other users. This paper resolves the possible conflicts among the multiple user commands through a distributed clustering algorithm that allocates to each user a number of remote robots proportional to the urgency of their request. A pivotal design challenge in the teleoperation context is to ensure that the remote robots allocated to each user are topologically reachable from the user’s local robot within the induced communication subnetwork. The proposed design overcomes this challenge through a reachability-constrained integer linear program that modulates the interconnections of the remote robots on the fly. A comparative experiment on a platform with 2 local and 12 remote robots validates the practical efficacy of the proposed clustering algorithm.

This paper proposes a strategy to overcome the threats posed to connectivity-preserving synchronization of Euler-Lagrange networks by time-varying delays and bounded actuation. It first introduces a suitable distributed negative gradient plus damping injection controller, based on which it establishes that the local connectivity of time-delay Euler-Lagrange networks can be preserved by appropriately regulating the interagent connections and increasing the damping injection locally. Yet, actuator saturation may impede the proper modulation of the interagent connections and the injection of sufficient damping and, thus, may threaten the maintenance of connectivity. This paper then develops an indirect coupling control framework which integrates the bounded actuation constraints into the control design. The framework endows every agent with a virtual proxy and couples initially adjacent agents through their virtual proxies. The interproxy couplings then tackle the time-varying delays while the agent-proxy couplings account for the saturation of actuators. Lyapunov-Krasovskii analysis proves that the indirect coupling strategy can drive time-delay Euler-Lagrange networks with bounded actuation to connectivity-preserving synchronization by limiting the energy of the agent-proxy and interproxy couplings according to the actuation constraints. Experiments with Geomagic Touch haptic robots validate the proposed designs compared to a conventional proportional plus damping controller.

In a distributed multi-master-multi-slave teleoperation system, the human users may compete against each other for the control of the team of slave robots. To win the competition, one operator would send the largest command to the slave group. For the sake of team cohesion, the slave group should follow the command of the winning operator and ignore the commands of the other users. To enable (i) the slave team to identify the winning operator, and (ii) each slave to determine whether to admit or discard the command it receives from its operator, this paper proposes a dynamic decision-making protocol that distinguishes the decision variable of the slave commanded by the winner from the decision variables of all other slave robots. The protocol only requires the slaves to exchange and evaluate their decision variables locally. Lyapunov stability analysis proves the theoretical convergence of the proposed decision-making algorithm. An experimental distributed winner-take-all teleoperation in a 3-masters-11-slaves teleoperation testbed validates its practical efficacy.

During swarm teleoperation, the operator may threaten the distance-dependent inter-robot communications and, with them, the connectivity of the slave swarm. To prevent the operator from disconnecting the swarm, this paper develops a constructive strategy to dynamically modulate the interconnections of, and the local damping injections at, all slave robots. Lyapunov-based set invariance analysis shows that the strategy preserves all interaction links in the tree network while synchronizing the slave swarm. By properly limiting the impact of the user command rather than rejecting it entirely, the proposed explicit gain update law enables the operator to guide the motion of the slave swarm to the extent to which it does not endanger swarm connectivity. An experiment illustrates that the proposed strategy can maintain the tree network connectivity of a teleoperated swarm.