Adaptive control with impedance of cooperative multi-robot system

SUMMARYConsidering undesired slippage between manipulated object and finger tips of a multi-robot system, adaptive control synthesis of the object grasping and manipulation is addressed in this paper. Although many studies can be found in the literature dealing with grasp analysis and grasp synthesis, most assume no slippage between the finger tips and the object. Slippage can occur for many reasons such as disturbances, uncertainties in parameters, and dynamics of the system. In this paper, system dynamics is analyzed using a new presentation of friction and slippage dynamics. Then an adaptive control law is proposed for trajectory tracking and slippage control of the object as well as compensation for parameter uncertainties of the system, such as mass properties and coefficients of friction. Stability of the proposed adaptive controller is studied analytically and the performance of the system is studied numerically.

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Reinforcement-Learning-Based Asynchronous Formation Control Scheme for Multiple Unmanned Surface Vehicles

Applied Sciences ◽

10.3390/app11020546 ◽

2021 ◽

Vol 11 (2) ◽

pp. 546

Author(s):

Jiajia Xie ◽

Rui Zhou ◽

Yuan Liu ◽

Jun Luo ◽

Shaorong Xie ◽

...

Keyword(s):

Reinforcement Learning ◽

Formation Control ◽

Rapid Development ◽

Gradient Algorithm ◽

Robot System ◽

Physical Relationship ◽

Unmanned Surface Vehicles ◽

Main Challenge ◽

Control Scheme ◽

Multi Robot

The high performance and efficiency of multiple unmanned surface vehicles (multi-USV) promote the further civilian and military applications of coordinated USV. As the basis of multiple USVs’ cooperative work, considerable attention has been spent on developing the decentralized formation control of the USV swarm. Formation control of multiple USV belongs to the geometric problems of a multi-robot system. The main challenge is the way to generate and maintain the formation of a multi-robot system. The rapid development of reinforcement learning provides us with a new solution to deal with these problems. In this paper, we introduce a decentralized structure of the multi-USV system and employ reinforcement learning to deal with the formation control of a multi-USV system in a leader–follower topology. Therefore, we propose an asynchronous decentralized formation control scheme based on reinforcement learning for multiple USVs. First, a simplified USV model is established. Simultaneously, the formation shape model is built to provide formation parameters and to describe the physical relationship between USVs. Second, the advantage deep deterministic policy gradient algorithm (ADDPG) is proposed. Third, formation generation policies and formation maintenance policies based on the ADDPG are proposed to form and maintain the given geometry structure of the team of USVs during movement. Moreover, three new reward functions are designed and utilized to promote policy learning. Finally, various experiments are conducted to validate the performance of the proposed formation control scheme. Simulation results and contrast experiments demonstrate the efficiency and stability of the formation control scheme.

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Decentralized Ability-Aware Adaptive Control for Multi-Robot Collaborative Manipulation

IEEE Robotics and Automation Letters ◽

10.1109/lra.2021.3060379 ◽

2021 ◽

Vol 6 (2) ◽

pp. 2311-2318

Author(s):

Lei Yan ◽

Theodoros Stouraitis ◽

Sethu Vijayakumar

Keyword(s):

Adaptive Control ◽

Multi Robot

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Voronoi-based Geometric Distributed Fleet Control of a Multi-Robot System

2020 16th International Conference on Control, Automation, Robotics and Vision (ICARCV) ◽

10.1109/icarcv50220.2020.9305373 ◽

2020 ◽

Author(s):

Sylvain Bertrand ◽

Ioannis Sarras ◽

Alexandre Eudes ◽

Julien Marzat

Keyword(s):

Robot System ◽

Multi Robot

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Research Progress on Synergistic Technologies of Agricultural Multi-Robots

Applied Sciences ◽

10.3390/app11041448 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1448

Author(s):

Wenju Mao ◽

Zhijie Liu ◽

Heng Liu ◽

Fuzeng Yang ◽

Meirong Wang

Keyword(s):

Path Planning ◽

Formation Control ◽

Research Progress ◽

Hybrid Architecture ◽

Labor Costs ◽

Robot System ◽

System Architectures ◽

Research Results ◽

Robot Systems ◽

Multi Robot

Multi-robots have shown good application prospects in agricultural production. Studying the synergistic technologies of agricultural multi-robots can not only improve the efficiency of the overall robot system and meet the needs of precision farming but also solve the problems of decreasing effective labor supply and increasing labor costs in agriculture. Therefore, starting from the point of view of an agricultural multiple robot system architectures, this paper reviews the representative research results of five synergistic technologies of agricultural multi-robots in recent years, namely, environment perception, task allocation, path planning, formation control, and communication, and summarizes the technological progress and development characteristics of these five technologies. Finally, because of these development characteristics, it is shown that the trends and research focus for agricultural multi-robots are to optimize the existing technologies and apply them to a variety of agricultural multi-robots, such as building a hybrid architecture of multi-robot systems, SLAM (simultaneous localization and mapping), cooperation learning of robots, hybrid path planning and formation reconstruction. While synergistic technologies of agricultural multi-robots are extremely challenging in production, in combination with previous research results for real agricultural multi-robots and social development demand, we conclude that it is realistic to expect automated multi-robot systems in the future.

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