Search results for "robotics"
showing 10 items of 484 documents
Integrated dimensional and drive-train design optimization of a light-weight anthropomorphic arm
2012
An approach to minimize the mass of robotic manipulators is developed by integrated dimensional and drive-train optimization. The method addresses the influences of dimensions and characteristics of drive-trains in the design optimization. Constraints are formulated on the basis of kinematic performance and dynamic requirements, whereas the main objective is to minimize the total mass. Case studies are included to demonstrate the application of the optimization method in the design of assistive robots.
The absolute center of a unicyclic network
1989
Abstract A unicyclic network is one generalization of a tree network. In this paper we examine the problem of finding an absolute center of a unicyclic network. We show that this problem can be solved in linear time with respect to the number of vertices in the network.
Attitude stabilization control of a quadrotor UAV by using backstepping approach
2014
Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2014/749803 The modeling and attitude stabilization control problems of a four-rotor vertical takeoff and landing unmanned air vehicle (UAV) known as the quadrotor are investigated. The quadrotor's attitude is represented by the unit quaternion rather than Euler angles to avoid singularity problem. Taking dynamical behavior of motors into consideration and ignoring aerodynamic effect, a nonlinear controller is developed to stabilize the attitude. The control design is accomplished by using backstepping control technique. The proposed control l…
Kinematic calibration method for a 5-DOF Gantry-Tau parallel kinematic machine
2013
In this paper a new step-wise approach to kinematic calibration of a 5-DOF Gantry-Tau parallel kinematic machine (PKM) is presented. The approach can be adapted to the modular design of the PKM and the calibration could easily perform part of the assembly instructions for the machine. By using measurements from a laser tracker and least-squares estimates of polynomial functions, a typical accuracy of about 20 micrometer was achieved for the base actuators. The remaining set of 30 general parameters for the hexapod link structure and spherical joint connections were successfully estimated using the Complex search-based evolutionary algorithm.
Nonholonomic Interpolation for Kinematic Problems, Entropy and Complexity
2008
Here we present the main lines of a theory we developed in a series of previous papers, about the motion planning problem in robotics. We illustrate the theory with a few academic examples.
Graph-based algorithms for the efficient solution of a class of optimization problems
2018
In this paper, we address a class of specially structured problems that include speed planning, for mobile robots and robotic manipulators, and dynamic programming. We develop two new numerical procedures, that apply to the general case and to the linear subcase. With numerical experiments, we show that the proposed algorithms outperform generic commercial solvers.
The Gantry-Tau parallel kinematic machine-kinematic and elastodynamic design optimisation
2011
Pubished version of an article in the journal: Meccanica. Also available from the publisher at: http://dx.doi.org/10.1007/s11012-010-9394-9 One of the main advantages of the Gantry-Tau machine is a large accessible workspace/footprint ratio compared to many other parallel machines. The optimal kinematic, elastostatic and elastodynamic design parameters of the machine are still difficult to calculate and this paper introduces an optimisation scheme based on the geometric and functional dependencies to define the workspace and first resonance frequency. This method assumes that each link and universal joint can be described by a mass-spring-damper model and calculates the transfer function fr…
Monte Carlo Application in Brachytherapy Dosimetry
2009
This paper devoted to Monte-Carlo Applications in BT Dosimetry is organized in four parts: 1. Motivation of the use of Monte Carlo in brachytherapy 2. The use of Monte Carlo to obtain dose distribution around brachytherapy sources 3. Experimental dosimetry versus Monte Carlo 4. Others Monte Carlo applications in brachytherapy
"Table 1" of "Measurement of double-differential muon neutrino charged-current interactions on C$_8$H$_8$ without pions in the final state using the …
2017
Total signal cross-section per nucleon integrated over all the muon kinematics phase space in Analysis I.
Rolling, Pitching and Yawing of a Superconducting Maglev Vehicle
1995
The dynamic characteristics of a Maglev vehicle are influenced by both the translational and the rotational degrees of freedom. As a result, the rolling, pitching and yawing motion modes must be included in a complete description of the dynamic features of a Maglev vehicle. Furthermore, the analysis of this motion modes is also very useful in order to obtain the highest achievable riding comfort.