A Framework to Illustrate Kinematic Behavior of Mechanisms by Haptic Feedback

The kinematic properties of mechanisms are well known by the researchers and teachers. The theory based on the study of Jacobian matrices allows us to explain, for example, the singular configuration. However, in many cases, the physical sense of such properties is difficult to explain to students. The aim of this article is to use haptic feedback to render to the user the signification of different kinematic indices. The framework uses a Phantom Omni and a serial and parallel mechanism with two degrees of freedom. The end-effector of both mechanisms can be moved either by classical mouse, or Phantom Omni with or without feedback

Telerobotics : methodology for the development of a through-the-internet robotic teleoperated system

This work presents a methodology for the development of Teleoperated Robotic Systems through the Internet. Initially, it is presented a bibliographical review of the Telerobotic systems that uses Internet as way of control. The methodology is implemented and tested through the development of two systems. The first is a manipulator with two degrees of freedom commanded remotely through the Internet denominated RobWebCam (http://www.graco.unb.br/robwebcam). The second is a system which teleoperates an ABB (Asea Brown Boveri) Industrial Robot of six degrees of freedom denominated RobWebLink (http://webrobot.graco.unb.br). RobWebCam is composed of a manipulator with two degrees of freedom, a video camera, Internet, computers and communication driver between the manipulator and the Unix system; and RobWebLink composed of the same components plus the Industrial Robot. With the use of this technology, it is possible to move far distant positioning objects minimizing transport costs, materials and people; acting in real time in the process that is wanted to be controller. This work demonstrates that the teleoperating via Internet of robotic systems and other equipments is viable, in spite of using rate transmission data with low bandwidth. Possible applications include remote surveillance, control and remote diagnosis and maintenance of machines and equipments

Dynamics and control of linkage mechanisms having two degrees of freedom

PhD ThesisThe work described in this thesis concerns the dynamics and control of linkage mechanisms having two degrees of freedom. The work, basically, deals with three topics. The first concerns the derivation of equations of motion, their numerical solution and linearised analysis involving the studies of resonance and stability. The second concerns optimisation of a general planar linkage to generate a given output and also controlling some of the linkage inputs to generate an output more closely. The third concerns experimental investigations to check the validity of the numerical solutions and the linearised analysis

A New Recursive Instrumental Variables Approach for Robot Identification

International audienceThe work presented in this paper focus on robot identification and presents a method based on the use of instrumental variables (IV). When dealing with en-bloc and offline identification of robots, the instrumental matrix constructed with the inverse dynamic model (IDM) and simulated data obtained from the simulation of the direct dynamic model (DDM). In this paper, a new recursive IV approach relevant for robot identification is presented. The instrumental matrix is constructed with the IDM and the references and their derivatives which are previously filtered by the transfer function of the position closed loop. This new way of building the instrumental matrix avoids the simulation of the DDM and offers some perspectives for online identification and real-time implementation. This recursive IV method termed IDIM-RIV (Inverse Dynamic Identification Model Recursive Instrumental Variables) is experimentally validated on the two degrees-of-freedom SCARA robot. Finally, some hints for real-time implementation are provided

A hyper-redundant manipulator

“Hyper-redundant” manipulators have a very large number of actuatable degrees of freedom. The benefits of hyper-redundant robots include the ability to avoid obstacles, increased robustness with respect to mechanical failure, and the ability to perform new forms of robot locomotion and grasping. The authors examine hyper-redundant manipulator design criteria and the physical implementation of one particular design: a variable geometry truss

Designing a dexterous reconfigurable packaging system for flexible automation

This paper presents a design for a reconfigurable packaging system that can handle cartons of different shape and sizes and is amenable to ever changing demands of packaging industries for perfumery and cosmetic products. The system takes structure of a multi-fingered robot hand, which can provide fine motions, and dexterous manipulation capability that may be required in a typical packaging-assembly line. The paper outlines advanced modeling and simulation undertaken to design the packaging system and discusses the experimental work carried out. The new packaging system is based on the principle of reconfigurability, that shows adaptability to simple as well as complex carton geometry. The rationale of developing such a system is presented with description of its human equivalent. The hardware and software implementations are also discussed together with directions for future research

Rapid assessment of the fuel economy capability of parallel and series-parallel hybrid electric vehicles

Efficiently solving the off-line control problem represents a crucial step to predict the fuel economy capability of hybrid electric vehicles (HEVs). Optimal HEV control approaches implemented in literature usually prove to be either computationally inefficient or sub-optimal. Moreover, they often neglect drivability and comfort associated to the generated control actions over time. This paper therefore aims at introducing a rapid near-optimal approach to solve the off-line control problem for parallel and series-parallel HEV powertrains while accounting for drivability criteria such as the frequency of gear shifts and the number of activations of the thermal engine. The performance of the introduced slope-weighted energy-based rapid control analysis (SERCA) algorithm is compared with the global optimal benchmark provided by dynamic programming (DP) for both the parallel and the series-parallel HEV layouts over different driving missions. Results demonstrate how the SERCA algorithm can produce comparable control results with respect to DP by limiting the increase in the estimated fuel consumption within 2.2%. The corresponding computational time can be simultaneously reduced by around 99.5% while ensuring a limited number of gear shifts and engine activations over time. Engineers could therefore potentially implement the proposed SERCA algorithm in design and calibration procedures of parallel and series-parallel HEVs to accelerate the overall vehicle development process