Differentially-Driven Robots Moving in Formation—Leader–Follower Approach (original) (raw)

An algorithm for formation control of mobile robots

Serbian Journal of Electrical Engineering, 2013

Solution of the formation guidance in structured static environments is presented in this paper. It is assumed that high level planner is available, which generates collision free trajectory for the leader robot. Leader robot is forced to track generated trajectory, while followers' trajectories are generated based on the trajectory realized by the real leader. Real environments contain large number of static obstacles, which can be arbitrarily positioned. Hence, formation switching becomes necessary in cases when followers can collide with obstacles. In order to ensure trajectory tracking, as well as object avoidance, control structure with several controllers of different roles (trajectory tracking, obstacle avoiding, vehicle avoiding and combined controller) has been adopted. Kinematic model of differentially driven two-wheeled mobile robot is assumed. Simulation results show the efficiency of the proposed approach.

Implementation of Leader-Follower Formation Control of a Team of Nonholonomic Mobile Robots

International Journal of Computers Communications & Control

A control method for a team of multiple mobile robots performing leader-follower formation by implementing computing, communication, and control technol-ogy is considered. The strategy expands the role of global coordinator system andcontrollers of multiple robots system. The global coordinator system creates no-collision trajectories of the virtual leader which is the virtual leader for all vehicles,sub-virtual leaders which are the virtual leader for pertinent followers, and virtualfollowers. The global coordinator system also implements role assignment algorithmto allocate the role of mobile robots in the formation. The controllers of the individualmobile robots have a task to track the assigned trajectories and also to avoid collisionamong the mobile robots using the artificial potential field algorithm. The proposedmethod is tested by experiments of three mobile robots performing leader-followerformation with the shape of a triangle. The experimental results show the robustness...

Formation control of mobile robots

World Academy of Science, Engineering and Technology, International Journal of Mechanical, Aerospace, Industrial, Mechatronic and Manufacturing Engineering, 2011

In this paper, we study the formation control problem for car-like mobile robots. A team of nonholonomic mobile robots navigate in a terrain with obstacles, while maintaining a desired formation, using a leader-following strategy. A set of artificial potential field functions is proposed using the direct Lyapunov method for the avoidance of obstacles and attraction to their designated targets. The effectiveness of the proposed control laws to verify the feasibility of the model is demonstrated through computer simulations.

Controlling Formations of Multiple Mobile Robots

1998

In this paper, we investigate the problem of inter-robot collision avoidance in multiple mobile robot formation control. Two methodologies are utilized, namely Virtual Robot tracking by and l-l control by ] to establish formation and avoid collision among robots. We point out that the framework in Virtual Robot tracking is potentially subject to collision among robots. This drawback is overcome in our design by incorporating a different reactive scheme in the incident possibility of collision. To prove the advantages of our framework, we demonstrate in simulation the case of three robots moving in formation and avoiding inter-robot collisions.

Controlling formations of multiple mobile robots with inter-robot collision avoidance

Investigation of Formation Control Approaches Considering the Ability of a Mobile Robot

International Journal of Robotics and Automation (IJRA) , 2018

This work investigates and compares various formation control approaches for mobile robots. A comprehensive literature review was conducted, with particular focus on the approaches' applicability to be implemented on real mobile robots with limited hard and software capabilities. A realistic model of mobile robots is introduced and its parameters are identifed with measurements from actual mobile robots. Later on, the model is extended and used within simulation studies of the various investigated approaches. A collision avoidance controller based on a formation controller is proposed and simulations are carried out. Experiments on real mobile robots are conducted for two formation controllers and for the proposed collision avoidance controller. It is shown that if the requirements resulting from the simulation studies are satisfied, an implementation on the real robots is possible

Formation-Based Control Scheme for Cooperative Transportation by Multiple Mobile Robots

Formation-based Control Scheme for Cooperative Transportation by Multiple Mobile Robots, 2015

Citation: Alpaslan Yufka, Metin Ozkan, Formation-Based Control Scheme for Cooperative Transportation by Multiple Mobile Robots, International Journal of Advanced Robotic Systems, 2015, 12:120. ISSN 1729-8806. DOI: 10.5772/60972. Abstract: This paper presents a motion planning and control scheme for a cooperative transportation system comprising a single rigid object and multiple autonomous non-holonomic mobile robots. A leader-follower formation control strategy is used for the transportation system in which the object is assumed to be the virtual leader; the robots carrying the object are considered followers. A smooth trajectory between the current and desired locations of the object is generated by considering the constraints of the virtual leader. In the leader-follower approach, the origin of the coordinate system attached to the center of gravity of the object, which is known as the virtual leader, moves along the generated trajectory while the real robots, which are known as followers, maintain a desired distance and orientation to the leader. An asymptotically stable tracking controller is used for trajectory tracking. The proposed approach is verified by simulations and real applications using Pioneer P3-DX mobile robots. Paper videos can be reached from this URLs: http://www.youtube.com/playlist?list=PLENSkat0854tcWruhIrH2eqzc\_Vwc\_2Rm http://www.ai-robotlab.ogu.edu.tr/gallery-movies.htm

Formation Control with Leadership Alternation for Obstacle Avoidance

IFAC Proceedings Volumes, 2011

This paper deals with leader-following formation control of a group of wheeled mobile robots (WMRs) when the leadership alternates among the robots of the group. In the problem presented here, firstly a scout robot is used to search for a path in a previously unknown environment with static obstacles. The path found by this scout is used as a reference for the leader of the multi-robot formation. As the group follows the trajectory preserving the formation, whenever any robot in the formation is closer than a limit threshold distance from an obstacle, this robot assumes the leadership. So the new leader must adequate its position to the reference trajectory, and, as a result of the formation control, the position of the whole group is also adjusted. This way, the whole group navigates avoiding collisions with obstacles. The mobile robots exchange their position information among themselves according to a prespecified communication directed graph (digraph). A different digraph is defined for each robot as a leader. Simulation results are presented for the formation control applied on this scenario.

A Survey of Multi-mobile Robot Formation Control

This paper denotes a survey on formation control of multi-mobile robot systems which drawn significant attention for the last years. It is concentrated on the stability of multi mobile robots when they obtained the required formation. Also this paper discusses the approaches of formation control and applications of them in changing and remote environments. Two classifications for the formation control methods are surveyed in this paper: the formation control strategies and the formation control stability. The differences among the surveyed approaches are discussed and the results are summarized.