Search results for "Robotics"
showing 10 items of 484 documents
Distributed GNSS-Based Time Synchronization and Applications
2016
The paper deals with synchronization standards, applications and challenges in the modern packet switched telecommunication networks. In recent years, the number of time-dependent services and systems only increases with the development of such areas as Internet of Things (IoT), industrial Internet, remote automation and robotics, precise positioning etc. In the paper, these emerging applications are discussed. An alternative way to the traditional centralized synchronization infrastructure is proposed. Compact and low-priced devices equipped with a Global Navigation Satellite System (GNSS) receiver and a reliable internal clock can be installed specifically in the places where they are nee…
<title>HAP: a hybrid system for reasoning about actions and plans in robotics</title>
1990
The paper describes the main ideas and principles of HAP (Hybrid representation of Actions and Plans), a system for hybrid representation and reasoning in advanced robotics. In this context, hybrid representation refers to the integration of both symbolic and analogic knowledge representation paradigms. In particular, the logic/symbolic component is based on a KL-ONE-like representation language. The system embeds "analogic experts", that are concurrent procedures operating in a direct and fast way on the world representation. These "experts" help the system in planning a correct temporal sequence of actions. As a reference scenario, assembly (and disassembly) problems are considered. The a…
Robotic total knee arthroplastyThe accuracy of CT-based component placement
2004
Accurate alignment of the components in total knee arthroplasty is important. By use of postoperative CT controls, we studied the ability of a robotic effector to accurately place and align total knee arthroplasty (TKA) components according to a purely CT-based preoperative plan.Robotic TKA was performed in 13 patients (6 men) with primary gonarthrosis. Locator screws were placed into femur and tibia under spinal anesthesia. A CT-scan including the femoral head, knee and ankle was performed. In the preoperative planning software, virtual components were positioned into the CT volume. In a second operation, the robot milled femur and tibia with a high-speed milling tool according to the preo…
Understanding dynamic scenes
2000
We propose a framework for the representation of visual knowledge in a robotic agent, with special attention to the understanding of dynamic scenes. According to our approach, understanding involves the generation of a high level, declarative description of the perceived world. Developing such a description requires both bottom-up, data driven processes that associate symbolic knowledge representation structures with the data coming out of a vision system, and top-down processes in which high level, symbolic information is in its turn employed to drive and further refine the interpretation of a scene. On the one hand, the computer vision community approached this problem in terms of 2D/3D s…
A cognitive approach to goal-level imitation
2008
Imitation in robotics is seen as a powerful means to reduce the complexity of robot programming. It allows users to instruct robots by simply showing them how to execute a given task. Through imitation robots can learn from their environment and adapt to it just as human newborns do. Despite different facets of imitative behaviours observed in humans and higher primates, imitation in robotics has usually been implemented as a process of copying demonstrated actions onto the movement apparatus of the robot. While the results being reached are impressive, we believe that a shift towards a higher expression of imitation, namely the comprehension of human actions and inference of its intentions…
Apprentissage de modalités auxiliaires pour la localisation basée vision
2018
In this paper we present a new training with side modality framework to enhance image-based localization. In order to learn side modality information, we train a fully convo-lutional decoder network that transfers meaningful information from one modality to another. We validate our approach on a challenging urban dataset. Experiments show that our system is able to enhance a purely image-based system by properly learning appearance of a side modality. Compared to state-of-the-art methods, the proposed network is lighter and faster to train, while producing comparable results.
Interaction Control of Robotic Manipulators Without Force Measurement
2010
This paper deals with a new adaptive force-position control of a robotic manipulator based on force estimation. Based on Lyapunov techniques will be proved that the control law guaranties tracking of the desired Cartesian trajectory along the contact plane and of a constant desired force along reciprocal direction, without force measuring. Extensive simulations with 2-DOF manipulator illustrates the followed approach.
Neural Petri Control: an application on a mobile robot
2006
In the present work, an innovative nonlinear controller of nonholonomic mechanical systems, characterized by a dynamic not well known model a priori, using a new neural model obtained by the combination of a Petri net with a neural network, is proposed. The performances of the control algorithm are evaluated for tasks of tracking of time trajectories. The study of the stability of the total system to closed loop is based on the Lyapunov theory. Simulation experiments, made taking into consideration a nonholonomic mobile robot, to two wheels, allowed to verify the theoretical results.
Fuzzy/Kalman Hierarchical Horizontal Motion Control of Underactuated ROVs.
2010
A new closed loop fuzzy motion control system including on-line Kalman's filter (KF) for the two dimensional motion of underactuated and underwater Remotely Operated Vehicle (ROV) is presented. Since the sway force is unactuated, new continuous and discrete time models are developed using a polar transformation. A new hierarchical control architecture is developed, where the high level fuzzy guidance controller generates the surge speed and the yaw rate needed to achieve the objective of planar motion, while the low level controller gives the thruster surge force and the yaw torque control signals. The Fuzzy controller ensures robustness with respect to uncertainties due to the marine envi…
Fuzzy motion control strategy for cooperation of multiple automated vehicles with passengers comfort
2008
This paper considers motion control for a cooperative system of automated passenger vehicles. It develops a cooperative scheme based on a decentralized planning algorithm which considers the vehicles in an initial open chain configuration. In this scheme the trajectories are intersections-free, and each trajectory is planned independently of the others. To ensure the stabilization of each vehicle in the planned trajectory, a fuzzy closed loop motion control is presented, where, based on the properties of the Fuzzy maps, the Lyapunov’s stability of the motion errors is demonstrated for all the vehicles. Based on the ISO 2631-1 standard, the saturation property of the Fuzzy maps guarantees lo…