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.
Indoor RF-based localization using fingerprint mapping requires an initial training step, which represents a time consuming process. This location methodology needs a database conformed with RSSI (Radio Signal Strength Indicator) measures from the communication transceivers taken at specific locations within the localization area. But, the real world localization environment is dynamic and it is necessary to rebuild the fingerprint database when some environmental changes are made. This paper explores the use of different interpolation functions to complete the fingerprint mapping needed to achieve the sought accuracy, thereby reducing the effort in the training step. Also, different distributions of test maps and reference points have been evaluated, showing the validity of this proposal and necessary trade-offs. Results reported show that the same or similar localization accuracy can be achieved even when only 50% of the initial fingerprint reference points are taken.
3 February 2009 in IEEE Transactions on Industrial Electronics
This paper presents the UJI Industrial Robotics Telelaboratory, which lets Ph.D. and Master's degree students perform robotics and computer vision tele-experiments. By using this system, students are able to program experiments remotely via the Web, in order to combine the use of a field-programmable gate array (FPGA) to provide real-time vision processing, a conveyor belt, and a Motoman industrial manipulator. This paper introduces the novel SNRP protocol (i.e., Simple Network Robot Protocol), which permits the integration of network robots and sensors within an e-learning platform in a simple and reliable manner. As long as the students are able to interact remotely with a real robotic scenario, this system helps students very much to learn robotics control techniques like visual servoing control, vision for industrial applications, and robotics manipulation. The various components of the system are connected via a 100BaseT Ethernet network and follow the SNRP protocol, which grants simple access to generic networked devices using enhanced HTTP-based connections. Moreover, the whole telelaboratory is connected to the Internet through a router that permits the user to control the networked devices according to security constraints. The SNRP architecture is compared with a Common Object Request Broker Architecture-based approach, which was used in a previous telelaboratory. This paper describes two principle contributions: the design of a novel SNRP network architecture for the intercommunication of robots and sensors within an e-learning telelaboratory and the integration of a programmable FPGA vision system, which allows students to learn not only robotic techniques but also the design of high-performance circuits for industrial vision 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.