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In independent component analysis (ICA) the common task is to achieve either spatial or temporal independence by linearly mapping into a feature space. If the data possesses both spatial and temporal structures such as a sequence of images or 3d-scans taken at fixed time intervals, we can require the transformed data to be as independent as possible in both domains. First introduced by Stone using...
The goal of multidimensional independent component analysis (MICA) lies in the linear separation of data into statistically independent groups of signals. In this work, we give an elementary proof for the uniqueness of this problem in the case of equally sized subspaces, showing that the separation matrix is essentially unique except for row permutation and scaling. The proof is based on the reinterpretation...
The paper considers an example of mechanical system with high relative degree: a fully actuated robot with elastic joints and the related control problem. The considered system is characterized by a uniform relative degree five, assuming as available output only the joints' angles. Two different strategies can be exploited to address this control problem. A first possibility is to use a full order...
This paper presents the design, development and implementation of a Hybrid Adaptive Fuzzy Controller (HAFC) suitable for real-time industrial applications. The developed HAFC consists of a weighted combination of the Direct Adaptive Fuzzy Controller (DAFC) and Indirect Adaptive Fuzzy Controller (IAFC) and a gradually activated supervisory controller. The unique feature of the HAFC is that no mathematical...
The current trend in robotics is to achieve robust, high-speed and precise robots that fulfill the industry's requirements. Parallel robots are proposed as the best solution for some of these tasks due to the advantages offered by their parallel kinematic structure. However, in order to take the most of these advantages, advanced model-based control approaches are needed. In this paper, the dynamic...
In this paper we propose a novel frequency domain approach for the identification of a multiple-input multiple-output (MIMO) system driven by temporally i.i.d. and spatially independent non-Gaussian processes. The system frequency response is obtained based on singular value decomposition of a matrix constructed based on the power-spectrum and slices of polyspectra of the system output. Since more...
We consider a variant of the time-optimal control of the acrobot and term it sub time-optimal. By exploiting the partially linearized structure obtained through a feedback linearization technique, we swing up the first link to the vertically upright position in optimal time and then stabilize the second link around its vertical equilibrium position. Rate constraints are imposed on the actuator and...
Surgeons are using robots as a tool to increase surgery accuracy and decrease procedure times. One of the main problems in robotic assisted orthopedic surgery is the force control in manipulator robots. It always has been subject of great study and interest in the scientific community, where the most common approach is to consider it as a hybrid control problem, due to their complexity and non-linearities...
Image registration is a necessary pre-requisite for multi-focus image fusion because before fusion the constituent images must be positioned properly with respect to a common coordinate system. A two-step registration method is proposed in this work. In first step, a global translation is determined by maximizing the mutual information of the source and the reference images and then it is applied...
In this paper we study the problem of estimating inner cyclic time intervals within repetitive motion sequences of top-class swimmers in a swimming channel. Interval limits are given by temporal occurrences of key-poses, i.e. distinctive postures of the body. A key-pose is defined by means of only one or two specific features of the complete posture. It is often difficult to detect such subtle features...
A coordinated strategy between wind and reversible hydro units for the mid-term that reduces the imbalance of wind power and improves system efficiency is proposed. A stochastic mixed integer linear model is used, which maximizes the joint profit of wind and hydro energies and Conditional Value at Risk (CVaR), where CVaR is the tool utilized to model risk. The offering strategies studied are: i) separate...
Due to the dynamic interaction, the motion of the arms alters the attitude and position of the base. To stabilize the centroid position of the base during on-orbital manipulation, we proposed the modeling concept of the "Base Centroid Virtual Manipulator (BCVM)" for free-floating multi-arm space robotic systems. Correspondingly, the trajectory planning method of the balance arm was addressed...
Autonomous target capturing is the key for space robot to perform on-orbital servicing tasks. To meet the requirement of complex and long-term task, large flexible appendages, such as solar paddles and antenna reflectors are usually mounted on the base of a space robot. Due to the structure vibration, it is very challenging to capture a free-floating target satellite. In this paper, we derived the...
Correlation between channel state and source symbol is under investigation for a joint source-channel coding problem. We investigate simultaneously the lossless transmission of information and the empirical coordination of channel inputs with the symbols of source and states. Empirical coordination is achievable if the sequences of source symbols, channel states, channel inputs and channel outputs...
In order to get full 3D model from consumer depth cameras, previous approaches used set of synchronized depth cameras or moved the depth sensor around the target object. This on-going work introduces a cost effective and convenient framework for filming dynamic 3D object. This set is comprised of a consumer depth camera, or RGBD sensor and a pair of mirrors. Because of the images reflected from two...
A single port surgery has merits as small scar and little physical burden of subject while it has narrow workspace and small range of operations because of the mechanical limits of the instruments. In order to enlarge the application range of single port surgery, it is important to increase the stiffness and the force of the instruments. This paper presents the design and simulation of a single-port...
The interest of series elastic actuators (SEAs) for legged robots has recently increased to achieve compliant interactions and efficient gaits. However, control of legged robots with SEAs is difficult due to the need to design controllers that take into account both torque and impedance feedback loops. The work presented here addresses this issue by proposing a critically-damped fourth order system...
This paper presents an approach to shank-foot trajectory control using computed-torque control method. The aim is to provide rehabilitative measures to help patients with lower limb disorders improve their mobility performance. This measure is achieved by designing a desired trajectory to be followed by the shank-foot model for the rehabilitative purpose. The shank-foot model is designed to depict...
Adaptive Control of an Aerial Manipulation Vehicle is discussed here. The aerial manipulation vehicle consisting of a quadrotor and a robotic arm has a highly coupled dynamics. The nonlinear coupling introduces additional forces and moments on the quadrotor which prevents it from precisely hovering at a position and tracking of reference trajectory. A decentralized control of robotic arm and quadrotor...
This article describes the implementation and use of a two-accelerometer system to measure the angle formed between lower joints of weightlifters during the execution of the technical gesture. Being aware of movement between joints will allow identifying bad moves and prevent injuries in athletes. Likewise, it will help in turn to rehabilitation for people with problems in the movement of their joints...
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