On Positioning and Vibration Control Application to Robotic Manipulators with a Nonideal Load Carrying

Jeferson J Lima,Dailhane G Bassinello,Angelo M Tusset,Frederic C Janzen,Grzegorz Litak,José M Balthazar,Davide Bernardini,Rodrigo T Rocha

doi:10.1155/2019/5408519

Abstract

In recent years, the evolution of artificial intelligence techniques has widely grown such that it gives new ways to improve human life, not only at work but also living. Nowadays, to the human being, physical human-robot interactions (PHRIs) have been presented very important and present itself as a major challenge for the current engineering. Therefore, this work designs and analyses a two-degree-of-freedom robotic arm with flexible joints driven by a DC motor. Due to the interaction between the robot links and flexible joints, the arm may present overshoots when it is moved such that it becomes difficult to manipulate the arm. Therefore, Magnetorheological dampers (MR damper or MR brake) are attached to the links of the arm in order to control such overshoot and provide a way to adjust the mechanical limitations of the arm. The dynamics of the system will be investigated, showing the appearance of chaotic behavior due to the coupling of the manipulator to the motors. After that, the feedback control is obtained through the state-dependent Riccati equation (SDRE) aiming the control of the positioning of the manipulator and the torque applied on the MR damper. Numerical results showed that the proposed control using hybrid actuators, DC motor, and MR brake was effective to control the position and behavior of the flexible joints of the manipulators.

Highlights

In recent years, the human interaction with intelligent systems, such as voice or video recognition devices, has grown exponentially due to the evolution of artificial intelligence techniques, physical human-robot interaction (PHRI) presents itself as a major challenge for current engineering
A large number of research studies have focused on the development of manipulators that are intrinsically safe. at is, manipulators in which can guarantee some level of collision safety in the absence of a controller through their mechanical properties
Vibrations which appear during the positioning of the robotic arm should be controlled to improve safety PHRI, which is important for increasing efficiency and operation precision

Summary

Introduction

The human interaction with intelligent systems, such as voice or video recognition devices, has grown exponentially due to the evolution of artificial intelligence techniques, physical human-robot interaction (PHRI) presents itself as a major challenge for current engineering. In [25], the authors demonstrated the efficiency of the application of the magnetorheological (MR) brake in the positioning control of the two-degree-of-freedom robotic arm designed with flexible joints. E present paper is a continuation of the previous developments [25]; the modelling of the MR damper is performed by the use of the explicit mathematical model In this way, this work considers the positioning control of the dynamical behavior of a robot manipulator arm with flexible joints driven by a DC motor and MR brake, controlled for a feedback control obtained by the SDRE control, and considering a nonideal load carrying, and the control of the chaotic behavior. Where α θ1 − θ2, β θ1 − θ3, and δ θ2 − θ3. e interaction between the engine and the handler presents nonoptimal characteristic, expressed by the spring component ks; the potential energy is given by the gravity force acting on each link and the torsional stiffness of each link, denoted by the following equation:

V 2ks θ4

C14 C24 C34 0

A Volts Nm3