Systems that implement robot joints by using servo valve-controlled hydraulic actuators are known to be difficult to control because hydraulic systems are highly nonlinear. Although this problem is tough to solve, the...
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ISBN:
(纸本)9781509008223
Systems that implement robot joints by using servo valve-controlled hydraulic actuators are known to be difficult to control because hydraulic systems are highly nonlinear. Although this problem is tough to solve, these systems continue to be of interest because their hydraulic manipulators have a high power-to-weight ratio, which can be used for a variety of tasks. In order to enable a hydraulic manipulator to perform these tasks, the position and orientation of its end-effector must be controlled. We have designed Virtual Spring-damper (VSd) hypothesis based quaternion controller to control the orientation of a hydraulic manipulator end-effector. VSd hypothesis is a relatively simple calculation method that uses virtual force and joint damping to move the end-position of a robot arm to the desired position (control point). We extended VSd hypothesis for orientation control and connected 2 additional VSd models to the wrist and thumb in order to control the orientation of an end-effector with 3 degrees of freedom (doF). We have proposed a quaternion controller to determine control points used as input for each VSd model. We have also designed VSd controller to calculate the control input of joints; this input is used for the movement to each control point. In order to verify the performance of the proposed control method, we present the results of experiments performed on a hydraulic manipulator with 7 doF.
This paperdescribes a position based in-motion alignment method for underwater navigation of an AUV(Autonomous Underwater Vehicle). For proper estimation of the position and orientation of the AUV the navigation algo...
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The discussion delves into a prey-predator model encompassing three species, incorporating intra-specific coefficients alongside interval biological parameters, utilizing the concept of a difference equation. Analysis...
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In this paper, the voltage regulation of dC-dC boost converters is investigated in the existence of unmodeled system dynamics and load perturbations. An adaptive observer based sliding mode controller (SMC) is propose...
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The outstanding mechanical strength of as-depositeddC-electrodeposited nanocrystalline (nc) Ni-Fe alloys has been the subject of numerous researches in view of their scientific and practical interest. However, recent...
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We wish to correct some inaccuracies in our published article. In Eqs. (2) and (3), some symbols require refinement. The corrected equations are as follows: [Formula presented] [Formula presented] These corrections do...
This work aims to study the mathematical model of the coronavirus disease, which affects human beings. A deterministic mathematical model for coronavirus disease among the population, including the vaccinated populati...
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diffusion of cesium in borosilicate glass for high-level radioactive waste is discussed. For this purpose model glasses with non-radioactive elements are being made, in accordance with the specifications of the reproc...
diffusion of cesium in borosilicate glass for high-level radioactive waste is discussed. For this purpose model glasses with non-radioactive elements are being made, in accordance with the specifications of the reprocessing plants, from which concentration couples are composed. A concentration couple consists of two cylinders of borosilicate glass which contain different amounts of cesium. After heat treatment the couples are studied by means of scanning electron microscopy and X-ray microanalysis. The model study will provide a basis for predictions of the containment achieved over a longer period of time.
This paper is devoted to a multi-mesh-scale approach fordescribing the dynamic behaviors of thin geophysical mass flows on complex *** the topographic surfaces are generally non-trivially curved,we introduce an appro...
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This paper is devoted to a multi-mesh-scale approach fordescribing the dynamic behaviors of thin geophysical mass flows on complex *** the topographic surfaces are generally non-trivially curved,we introduce an appropriate local coordinate system fordescribing the flow behaviors in an efficient *** complex surfaces are supposed to be composed of a finite number of triangle *** to the unequal orientation of the triangular elements,the distinct flux directions add to the complexity of solving the riemann problems at the boundaries of the triangular ***,a vertex-centered cell system is introduced for computing the evolution of the physical quantities,where the cell boundaries lie within the triangles and the conventional riemann solvers can be ***,there are two mesh scales:the element scale for the local topographic mapping and the vertex-centered cell scale for the evolution of the physical *** final scheme is completed by employing the HLL-approach for computing the numerical flux at the *** numerical examples and one application to a large-scale landslide are conducted to examine the performance of the proposed approach as well as to illustrate its capability in describing the shallow flows on complex topographies.
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