Jorge Barrio

Bidirectional Transport Protocol for Teleoperated Robots

This paper describes a new Internet transport protocol applied to teleoperated tasks. This protocol, called bidirectional transport protocol (BTP), has demonstrated reliable performance regarding time spent for packet transmission. This protocol provides a novel congestion control technique which enhances application and transport layer performance. Internet still has some limitations, such as variable jitter, bandwidth, or congestion. New techniques have to be looked into so as to enable proper bilateral teleoperation. Most research to date focuses on the application layer such as control techniques (e.g., passivity) or predictive displays. Only a few studies are devoted to the transport layer or communication protocols. A testbed based on master-slave architecture has been used for testing BTP versus user datagram protocol (UDP). Transmission control protocol flows also coexist with the transmitted teleoperation data. Results show that the proposed protocol significantly enhances the UDP approach by achieving a minimum round trip time and interarrival time in relation to the available bandwidth of the network.

MasterFinger: Multi-finger Haptic Interface for Collaborative Environments

This paper introduces the MasterFinger developemt and application, a multi-finger haptic interface for virtual object manipulation. This haptic device, with a modular interface, is specially designed to perform collaborative tasks. Each module is in charge of managing the haptic interaction with a finger. The mechanical structure of the module is based on a serial-parallel structure linked to the finger thimble by a gimble with its own controller. Cooperative applications based on MasterFinger-2 (MF2) are also described in this study. Results from these applications show that multifinger interface is a significant leap in haptic devices since precise object grasping and collaborative manipulation by using two hands are successfully performed.

Evaluation of weight perception during unimanual and bimanual manipulation of virtual objects

Design of haptic interfaces for precise bimanual manipulation should take into account how weight simulation is implemented when manipulation switches between one and two hands. The importance of this is apparent in tasks where the user requires to apply vertical forces to penetrate a surface with a tool or splice a fragile object using one and/or two hands. Accurate perception of simulated weight should allow the user to execute the task with high precision. Here, we evaluated unimanual and bimanual weight perception when lifting virtual boxes of different weights with precision grip in a coupled Master Finger 2 setup. Initial results with virtual weights are similar to results from studies which used real weights [1] even though the users appear to be less sensitive to virtual weights. Implications for haptic interface design are discussed.

Sensorized thimble for haptics applications

This article describes the design and development of a thimble-sensor used for virtual object manipulation. This thimble is specially designed to provide the force information applied on an object by using four FlexiForce sensors and a fingertip orientation. Likewise, the aim of this paper is focused on the mechanical design, which relies on developing an adjustable mechanical tool non-finger-size dependant.

Multifinger haptic interface for bimanual manipulation of virtual objects

A multi-finger haptic interface called MasterFinger for bimanual manipulation of virtual objects is described in this paper. The index fingers and the thumbs are inserted in their corresponding thimbles in order to perform virtual manipulations. A gimble with 3-rotational degree of freedom connects the thimble to a serial-parallel mechanical structure that is made up of 3 electro-mechanical actuators. This mechanism thereby provides 6 DoF of movement with force reflection in all directions. A distributed architecture has been implemented to simulate bimanual manipulations. This architecture is based on the use of a specific controller for each finger and a server computer that simulates the virtual manipulation in real time. Some experiments that evaluate the performance of the MasterFinger are described.

Efficient Transport Protocol for Networked Haptics Applications

The performance of haptic application is highly sensitive to communication delays and losses of data. It implies several constraints in developing networked haptic applications. This paper describes a new internet protocol called Efficient Transport Protocol (ETP), which aims at developing distributed interactive applications. TCP and UDP are transport protocols commonly used in any kind of networked communication, but they are not focused on real time application. This new protocol is focused on reducing roundtrip time (RTT) and interpacket gap (IPG). ETP is, therefore, optimized for interactive applications which are based on processes that are continuously exchanging data. ETP protocol is based on a state machine that decides the best strategies for optimizing RTT and IPG. Experiments have been carried out in order to compare this new protocol and UDP.

Advanced Virtual Manipulation based on Modular Haptic Devices

Abstract This paper describes a multi-finger haptic interface called MasterFinger which is being developed by the Universidad Politecnica de Madrid, Spain. An index and thumb finger prototype has already been implemented. Details about this device and how it is integrated into haptic scenarios are hereby explained. The paper includes mechanical and control description of the device, as well as some examples of the developed scenarios.

Teleoperation platform for multimodal experimentation

This paper describes the design strategy of an experimental platform which works as a test bed for teleoperation. It studies the performance of the executed tasks with different configurations and settings. The two key elements of a teleoperation interface are haptics and video perception. They inform the operator about the status of the remote or virtual environment. Specific hardware has been developed for both interactions as explained in the paper. These specific hardware components allow studying different control scheme for haptic devices and visual stereoscopic images on a computer screen. Results of the tests to this date are shown at the end and up-coming experiments are proposed.

A rate-position haptic controller for large telemanipulation workspaces

This paper presents a new Haptic Rate-Position controller, which allows manipulating a slave robot in a large workspace. Haptic information is displayed to the user so as to be informed when a change in the operation mode occurs. This controller allows performing tasks in a large remote workspace by using a haptic device with a reduced workspace such as Phantom. Experimental results have been carried out using a virtual slave robot, simulated with Open Dynamics Engine (ODE). A real IFMIF (International Fusion Materials Irradiation Facility) remote handling task has been simulated. Its goal is to carry out remote manipulation of test irradiated materials in a nuclear environment. The proposed algorithm has been compared with the classic Position controller in a Pick & Place manipulation and has shown much better levels of effectiveness.

Haptic Rendering Methods for Multiple Contact Points

Vast majority of haptic applications are focused on single contact point interaction between the user and the virtual scenario. One contact point is suitable for haptic applications such as palpation or object exploration. However, two or more contact points are required for more complex tasks such as grasping or object manipulation. Traditionally, when single-point haptic devices are applied in a complex task, a key or a switch is used for grasping objects. Using multiple contact points for this kind of complex manipulation tasks significantly increases the realism of haptic interactions. Moreover, virtual scenarios with multiple contact points also allow developing multi-user cooperative virtual manipulation since several users simultaneously interact over the same scenario and perceive the actions being performed by others. It represents a step forward in the current haptic applications that are usually based on one single user.