1,141 research outputs found
Synchronized closed path following for a differential drive and manipulator robot
Li, Y., & Nielsen, C. (2017). Synchronized Closed Path Following for a Differential Drive and Manipulator Robot. IEEE Transactions on Control Systems Technology, 25(2), 704–711. https://doi.org/10.1109/TCST.2016.2562578We locally solve a synchronized path-following problem for a heterogeneous multiagent system consisting of a differential drive robot and a serial manipulator. Each is assigned a simple, regular, and closed curve in its output space. The outputs of the systems must approach and traverse their assigned curves while synchronizing their motions along the paths. We use the notion of path-following outputs to facilitate a solution and present a novel synchronization controller and a novel singularity avoidance controller. The controllers are all given in closed form making their implementation straightforward. A numerical simulation is presented, which includes modeling uncertainty to demonstrate the utility of this approach.Partially supported by the Natural Sciences and Engineering Research
Council of Canada (NSERC
Cooperative Control of the Dual Gantry-Tau Robot
Utilization of multiple parallel robots operating in the same work place and cooperating
on the same job have opened up new challenges in coordination control strategies.
Multiple robot control is a natural progression for Parallel Kinematic Machines (PKM) as
it offers many of the desirable qualities especially in cooperative arrangements where
multiple robots can be associated with an easily reconfigurable parallel machine. These
special characteristics allow much faster and precise manipulations especially in
manufacturing industries. With the possibility of cooperative control architecture, PKMs
will be able to perform many of the tasks currently requiring dual serial robots such as
complex assemblies, heavy load sharing and large machining jobs
Synchronized closed-path following for a mobile robot and an Euler-Lagrange system
We propose and solve a synchronized path following problem for a differential drive
robot modeled as a dynamic unicycle and an Euler-Lagrange system. Each system is assigned
a simple closed curve in its output space. The outputs of systems must approach and
traverse their assigned curves while synchronizing their motions along the paths. The synchronization
problems we study in this thesis include velocity synchronization and position
synchronization. Velocity synchronization aims to force the velocities of the systems be equal
on the desired paths. Position synchronization entails enforcing a positional constraint
between the systems modeled as a constraint function on the paths. After characterizing
feasible positional constraints, a finite-time stabilizing control law is used to enforce the
position constraint
Adaptive Path Following for an Underactuated Nonholonomic Mobile Manipulator
We investigate an adaptive path following problem for an underactuated nonholonomic mobile manipulator system and closed planar curves. As opposed to adapting to uncertain or unknown dynamics in the plant, we apply an adaptation approach with respect to an unknown geometric path. First, we present a solution to the non-adaptive path following problem using the concept of a path following output and apply it to circular and elliptical paths. To overcome a drawback associated with our first proposed solution and set the stage for our approach to the adaptive case, we apply an approximation approach based on osculating circles for strictly convex closed curves.
We transition to the adaptive path following case by first presenting an algorithm to estimate unknown path parameters in the case of a circular path. We use our estimation algorithm and our path following solution for circular paths in an indirect adaptive control scheme. Thereafter, again using the osculating circle of a curve and the approximation technique of our second non-adaptive path following solution, we extend our adaptive solution, under some mild assumptions, for unknown strictly convex closed curves in the plane
Hybrid Simulator for Space Docking and Robotic Proximity Operations
In this work, we present a hybrid simulator for space docking and robotic
proximity operations methodology. This methodology also allows for the
emulation of a target robot operating in a complex environment by using an
actual robot. The emulation scheme aims to replicate the dynamic behavior of
the target robot interacting with the environment, without dealing with a
complex calculation of the contact dynamics. This method forms a basis for the
task verification of a flexible space robot. The actual emulating robot is
structurally rigid, while the target robot can represent any class of robots,
e.g., flexible, redundant, or space robots. Although the emulating robot is not
dynamically equivalent to the target robot, the dynamical similarity can be
achieved by using a control law developed herein. The effect of disturbances
and actuator dynamics on the fidelity and the contact stability of the robot
emulation is thoroughly analyzed
Innovative Mobile Manipulator Solution for Modern Flexible Manufacturing Processes
There is a paradigm shift in current manufacturing needs that is causing a change from the current mass-production-based approach to a mass customization approach where production volumes are smaller and more variable. Current processes are very adapted to the previous paradigm and lack the required flexibility to adapt to the new production needs. To solve this problem, an innovative industrial mobile manipulator is presented. The robot is equipped with a variety of sensors that allow it to perceive its surroundings and perform complex tasks in dynamic environments. Following the current needs of the industry, the robot is capable of autonomous navigation, safely avoiding obstacles. It is flexible enough to be able to perform a wide variety of tasks, being the change between tasks done easily thanks to skills-based programming and the ability to change tools autonomously. In addition, its security systems allow it to share the workspace with human operators. This prototype has been developed as part of THOMAS European project, and it has been tested and demonstrated in real-world manufacturing use cases.This research was funded by the EC research project “THOMAS—Mobile dual arm robotic workers with embedded cognition for hybrid and dynamically reconfigurable manufacturing systems” (Grant Agreement: 723616) (www.thomas-project.eu/)
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