Coordination of several robots based on temporal synchronization

© 2016. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/This paper proposes an approach to deal with the problem of coordinating multi-robot systems, in which each robot executes individually planned tasks in a shared workspace. The approach is a decoupled method that can coordinate the participating robots in on-line mode. The coordination is achieved through the adjustment of the time evolution of each robot along its original planned geometric path according to the movements of the other robots to assure a collision-free execution of their respective tasks. To assess the proposed approach different tests were performed in graphical simulations and real experiments.Postprint (published version

Kinematic Modeling And Path Planning With Collision Avoidance For Multiple Cartesian Arms

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2006Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2006Kartezyen robotlar, endüstride geniş kullanım alanı bulmaktadır. Birden fazla kartezyen robotun ortak bir iş yapmasına gerek duyulan durumlar vardır. Bu tezde yapılan çalışmanın temeli, aynı çalışma uzayındaki kartezyen robotların çarpışma olmaksızın yörünge planlamasıdır. Bu çalışmanın amacı, aynı çalışma uzayındaki kartezyen robotların konumlandırılması için gerekli algoritmaları bulmak veya türetmektir. Çarpışma sakınımlı yörünge planlaması algoritmalarını kullanarak istenen işin başarılması uzaysal işlem cebriyle kinematik olarak modellenmiş robotik sisteme dayanır. Yörünge planlaması metodları kartezyen robotlara uygulanarak çarpışma olmayan yörüngenin bulunması için algoritmalar geliştirilir.Cartesian robots are already being widely used in industry and their use will substantially increase as the developing technology brings the prices down of high payload and high precision linear motors. There are applications where more than one cartesian robots are required to perform a common task. The focus of the research presented in this thesis is the collision free path planning for multiple cartesian robots sharing the same task space. The objective of this research is to obtain or derive necessary algorithms to coordinate multiple cartesian robots sharing the same workspace. Using path planning algorithms with collision avoidance, the desired task is achieved based on the kinematic model of the complete robotic system which is rooted in the spatial operator algebra. Path planning methods are applied to the cartesian robots and the algorithms to find collision-free path for the cartesian robots are developed.Yüksek LisansM.Sc

Robust Execution of Contact-Rich Motion Plans by Hybrid Force-Velocity Control

In hybrid force-velocity control, the robot can use velocity control in some directions to follow a trajectory, while performing force control in other directions to maintain contacts with the environment regardless of positional errors. We call this way of executing a trajectory hybrid servoing. We propose an algorithm to compute hybrid force-velocity control actions for hybrid servoing. We quantify the robustness of a control action and make trade-offs between different requirements by formulating the control synthesis as optimization problems. Our method can efficiently compute the dimensions, directions and magnitudes of force and velocity controls. We demonstrated by experiments the effectiveness of our method in several contact-rich manipulation tasks. Link to the video: https://youtu.be/KtSNmvwOenM.Comment: Proceedings of IEEE International Conference on Robotics and Automation (ICRA2019

Challenges and Solutions for Autonomous Robotic Mobile Manipulation for Outdoor Sample Collection

In refinery, petrochemical, and chemical plants, process technicians collect uncontaminated samples to be analyzed in the quality control laboratory all time and all weather. This traditionally manual operation not only exposes the process technicians to hazardous chemicals, but also imposes an economical burden on the management. The recent development in mobile manipulation provides an opportunity to fully automate the operation of sample collection. This paper reviewed the various challenges in sample collection in terms of navigation of the mobile platform and manipulation of the robotic arm from four aspects, namely mobile robot positioning/attitude using global navigation satellite system (GNSS), vision-based navigation and visual servoing, robotic manipulation, mobile robot path planning and control. This paper further proposed solutions to these challenges and pointed the main direction of development in mobile manipulation

On-orbit assembly using superquadric potential fields

The autonomous on-orbit assembly of a large space structure is presented using a method based on superquadric artificial potential fields. The final configuration of the elements which form the structure is represented as the minimum of some attractive potential field. Each element of the structure is then considered as presenting an obstacle to the others using a superquadric potential field attached to the body axes of the element. A controller is developed which ensures that the global potential field decreases monotonically during the assembly process. An error quaternion representation is used to define both the attractive and superquadric obstacle potentials allowing the final configuration of the elements to be defined through both relative position and orientation. Through the use of superquadric potentials, a wide range of geometric objects can be represented using a common formalism, while collision avoidance can make use of both translational and rotation maneuvers to reduce total maneuver cost for the assembly process