Dynamic modeling, property investigation, and adaptive controller design of serial robotic manipulators modeled with structural compliance

Research results on general serial robotic manipulators modeled with structural compliances are presented. Two compliant manipulator modeling approaches, distributed and lumped parameter models, are used in this study. System dynamic equations for both compliant models are derived by using the first and second order influence coefficients. Also, the properties of compliant manipulator system dynamics are investigated. One of the properties, which is defined as inaccessibility of vibratory modes, is shown to display a distinct character associated with compliant manipulators. This property indicates the impact of robot geometry on the control of structural oscillations. Example studies are provided to illustrate the physical interpretation of inaccessibility of vibratory modes. Two types of controllers are designed for compliant manipulators modeled by either lumped or distributed parameter techniques. In order to maintain the generality of the results, neither linearization is introduced. Example simulations are given to demonstrate the controller performance. The second type controller is also built for general serial robot arms and is adaptive in nature which can estimate uncertain payload parameters on-line and simultaneously maintain trajectory tracking properties. The relation between manipulator motion tracking capability and convergence of parameter estimation properties is discussed through example case studies. The effect of control input update delays on adaptive controller performance is also studied

RC-SERVO AND IR-SENSOR CONTROL ON MOBILE PLATFORMS

ABSTRAC

Tyrol: Evolution Of A 10-Axis Biped Robot

This paper presents work demonstrating the evolution of a biped robot named Tyrol from a simulation environment to physical realization. For the past few years, humanoid robot development has been receiving increasing interest by several research groups. The design of this class of robots is quite challenging because of a variety of reasons such as the high number of degrees of freedom involved, balancing issues, power to weight ratio, and complexity of their control. By studying the development of a biped robot, this work addresses humanoid robot design and control in a bottom-up approach. For this purpose, a ten-degree-of-freedom biped robot concept was developed, modeled and constructed. Different gait algorithms have been developed for the biped robot to navigate on flat and inclined surfaces

Position Tracking Performance of a Redundant Teleoperation System

Teleoperation has captured the interest of robotics researchers for more than two decades. Many focused on the stability problem when the system experiences time delays. Most of the time, guaranteeing stability has overshadowed the tracking performance. This work differentiates teleoperation systems into two groups as limited and unlimited-workspace teleoperation depending on their position tracking priorities. Specifically, this paper examines limited-workspace teleoperation on a redundant system. The slave is modeled to be the virtual representation of a Fanuc LR Mate 100iB, a five degree-of-freedom (DOF) serial industrial manipulator. The master is selected as a two-DOF force-reflecting joystick. Hence, the teleoperation system is redundant since the degree-of-freedom of the slave is greater than the master. Teleoperation experiments have been conducted for this system under constant time delays and communication losses. The results are presented when the customary and modified wave variable techniques are utilized

Xanthus: Self-Reconfigurable Modular Robot

Second generation self-reconfigurable modular robotic system Xanthus developed at FIU is presented in this paper. The robot is capable of self-reconfiguring its mechanical structure for efficient walking and crawling as the previous version. In addition, the current version is able to reconfigure and roll conforming to the terrain. In both versions, changing modes is accomplished without human intervention. This work addresses mechanical design, hardware, control and software development for all- terrain navigation. Algorithms for quadruped walking, crawling and rolling are generated and tested on the prototype