564 research outputs found
A guiding vector field algorithm for path following control of nonholonomic mobile robots
In this paper we propose an algorithm for path following control of the nonholonomic mobile robot based on the idea of the guiding vector field (GVF). The desired path may be an arbitrary smooth curve in its implicit form, that is, a level set of a predefined smooth function. Using this function and the robot’s kinematic model, we design a GVF, whose integral curves converge to the trajectory. A nonlinear motion controller is then proposed which steers the robot along such an integral curve, bringing it to the desired path. We establish global convergence conditions for our algorithm and demonstrate its applicability and performance by experiments with wheeled robots
Guiding Vector Field Algorithm for a Moving Path Following Problem
This paper presents a guidance algorithm solving the problem of moving path following, that is, steering a mobile robot to a curvilinear path attached to a moving frame. The nonholonomic robot is described by the unicycle-type model under the influence of some constant exogenous disturbance. The desired path may be an arbitrary smooth curve in its implicit form, that is, a level set of some known smooth function. The path following algorithm employs a guiding vector field, whose integral curves converge to the trajectory. Experiments with a real fixed wing unmanned aerial vehicle (UAV) as well as numerical simulations are presented, illustrating the performance of the proposed path following control algorithm
A Novel Vector-Field-Based Motion Planning Algorithm for 3D Nonholonomic Robots
This paper focuses on the motion planning for mobile robots in 3D, which are
modelled by 6-DOF rigid body systems with nonholonomic kinematics constraints.
We not only specify the target position, but also bring in the requirement of
the heading direction at the terminal time, which gives rise to a new and more
challenging 3D motion planning problem. The proposed planning algorithm
involves a novel velocity vector field (VF) over the workspace, and by
following the VF, the robot can be navigated to the destination with the
specified heading direction. In order to circumvent potential collisions with
obstacles and other robots, a composite VF is designed by composing the
navigation VF and an additional VF tangential to the boundary of the dangerous
area. Moreover, we propose a priority-based algorithm to deal with the motion
coupling issue among multiple robots. Finally, numerical simulations are
conducted to verify the theoretical results
Circular formation control of fixed-wing UAVs with constant speeds
In this paper we propose an algorithm for stabilizing circular formations of
fixed-wing UAVs with constant speeds. The algorithm is based on the idea of
tracking circles with different radii in order to control the inter-vehicle
phases with respect to a target circumference. We prove that the desired
equilibrium is exponentially stable and thanks to the guidance vector field
that guides the vehicles, the algorithm can be extended to other closed
trajectories. One of the main advantages of this approach is that the algorithm
guarantees the confinement of the team in a specific area, even when
communications or sensing among vehicles are lost. We show the effectiveness of
the algorithm with an actual formation flight of three aircraft. The algorithm
is ready to use for the general public in the open-source Paparazzi autopilot.Comment: 6 pages, submitted to IROS 201
Experimental comparison of control strategies for trajectory tracking for mobile robots
The purpose of this paper is to implement, test and compare the performance of different control strategies for tracking trajectory for mobile robots. The control strategies used are based on linear algebra, PID controller and on a sliding mode controller. Each control scheme is developed taking into consideration the model of the robot. The linear algebra approaches take into account the complete kinematic model of the robot; and the PID and the sliding mode controller use a reduced order model, which is obtained considering the mobile robot platform as a black-box. All the controllers are tested and compared, firstly by simulations and then, by using a Pioneer 3DX robot in field experiments.Fil: Capito, Linda. Escuela PolitĂ©cnica Nacional; EcuadorFil: Proaño, Pablo. Escuela PolitĂ©cnica Nacional; EcuadorFil: Camacho, Oscar. Escuela PolitĂ©cnica Nacional; EcuadorFil: Rosales, AndrĂ©s. Escuela PolitĂ©cnica Nacional; EcuadorFil: Scaglia, Gustavo Juan Eduardo. Universidad Nacional de San Juan. Facultad de IngenierĂa. Instituto de IngenierĂa QuĂmica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - San Juan; Argentin
Adaptive Sliding Mode Tracking Control of Mobile Robot in Dynamic Environment Using Artificial Potential Fields
Solution to the safe and collision-free trajectory of the wheeled mobile robot in cluttered environments containing the static and/or dynamic obstacle has become a very popular and challenging research topic in the last decade. Notwithstanding of the amount of publications dealing with the different aspects of this field, the ongoing efforts to address the more effective and creative methods is continued. In this article, the effectiveness of the real-time harmonic potential field theory based on the panel method to generate the reference path and the orientation of the trajectory tracking control of the three-wheel nonholonomic robot in the presence of variable-size dynamic obstacle is investigated. The hybrid control strategy based on a backstepping kinematic and regressor-based adaptive integral sliding mode dynamic control in the presence of disturbance in the torque level and parameter uncertainties is employed. In order to illustrate the performance of the proposed adaptive algorithm, a hybrid conventional integral sliding mode dynamic control has been established. The employed control methods ensure the stability of the controlled system according to Lyapunov’s stability law. The results of simulation program show the remarkable performance of the both methods as the robust dynamic control of the mobile robot in tracking the reference path in unstructured environment containing variable-size dynamic obstacle with outstanding disturbance suppression characteristic
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