C. Murrugarra

Vision-Based Dynamic Velocity Field Generation for Mobile Robots

A control strategy much studied in the last years is the velocity field control (VFC). In 1995, velocity fields are defined as a set of velocity vectors located at each possible position of the robot platform inside its workspace coding a specified task [1]. The employment of a control scheme whose reference is a velocity field has allowed to encourage different control problems rather than the conventional timed trajectory tracking, such as contour following, position control, etc.

Design of a PD Position Control based on the Lyapunov Theory for a Robot Manipulator Flexible-Link

We propose the design of a PD position control for a one link flexible manipulator. This paper is based in development the scheme control using the theory Lyapunov, where the existence, unicity and asymptotic behavior of the equilibrium point is defined inside workspace of the robot manipulator, furthermore we are presenting a detailed mathematical development based in the dynamics of the robot, we proved that finding a Kp and Kv constants such as the controller converge to unique solutions. The workspace of the robot manipulator is defined in the x-y plane, with rotational joints under gravity force. The mathematical model considers the link as beam the Euler-Bernoulli. The Lagrange-Euler equation have been used to obtained generalized equation of movement and the method Assumed-Modes for modelling the transversal deformation of the beam in any point and to identify the position of the end-effector.

A Test Bed to Measure Transverse Deflection of a Flexible Link Manipulator

In this paper, we present a test bed to measure transverse deflection in different parts of a link of a manipulator of flexible links. For the mathematical modeling of the link, the Euler-Bernoulli beam theory has been used as a simplification of the linear elasticity theory, which allows calculating the load and the deflection characteristics of a beam. In order to measure the transverse deflection of the beam, we have used strain gauge arrangements that have been placed at three points of the flexible link, the test bed, allowing to reconstruct the position of the beam taking into account the actual position of the end-effector, the motion controller, and real-time interface PC. In addition to knowing with certainty the position of the manipulator arm, it has also been considered in the calculation of the manipulator dynamics using Euler-Lagrange and assumed modes for modeling the transverse deflection and the vibrations of the beam. This information will be used in modern control schemes to perform transverse deflection compensation, vibration suppression and ensure that the end-effector, reaches the set point set in the control system in a finite time.