Closed-Loop Systems
01 Jan 2013-pp 155-171
TL;DR: In this chapter, analyses of closed-loop systems are presented using the dynamic formulation given in Chaps.
Abstract: Closed-loops are inherent in many practical robotic systems In this chapter, analyses of closed-loop systems are presented using the dynamic formulation given in Chaps 5,6 and 7
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TL;DR: The idea was to see and measure the tendency of depression and anxiety through social media using the Closed-Loop method using Facebook text mining posts, and analysis and mapping of social demographics of users that are usually as a trigger of depression, and anxiety are available.
Abstract: The change of information and communication technology has brought many changes in daily life. The way humans interacting is changing. It is possible to express each form of communication directly and instantly. Social media has contributed data in size, diversity and capacity and quality. Based on it, the idea was to see and measure the tendency of depression and anxiety through social media using the Closed-Loop method using Facebook text mining posts. Through the stages of pre-processing including text extraction using the Naive Bayes machine learning model for text classification, the early signs of depression and anxiety are measured using DASS-21 parameter. In total, 22,934 Facebook posts were contributed as training and learning data collected from July 2017 until July 2018. As a results, analysis and mapping of social demographics of users that are usually as a trigger of depression, and anxiety, such as grief, illness, household affairs, children education and others are available.
21 citations
References
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01 Jan 1988TL;DR: This book provides a concise introduction to the behavior of mechanical structures and testing their stochastic stability under the influence of noise, and explains the physical effects of noise and in particular the concept of Gaussian white noise.
Abstract: Computer Aided Analysis Of Mechanical Computer-aided design (CAD) is the use of computers (or workstations) to aid in the creation, modification, analysis, or optimization of a design. CAD software is used to increase the productivity of the designer, improve the quality of design, improve communications through documentation, and to create a database for manufacturing. CAD output is often in the form of electronic files for print ...
1,123 citations
TL;DR: In this article, a new constraint wrench formulation for closed-loop systems is presented using two-level recursions, namely, subsystem level and body level, where a subsystem is referred here as the serial- or tree-type branches of a spanning tree obtained by cutting the appropriate joints of the closed loops of the system at hand.
Abstract: In order to compute the constraint moments and forces, together referred here as wrenches, in closed-loop mechanical systems, it is necessary to formulate a dynamics problem in a suitable manner so that the wrenches can be computed efficiently. A new constraint wrench formulation for closed-loop systems is presented in this paper using two-level recursions, namely, subsystem level and body level. A subsystem is referred here as the serial- or tree-type branches of a spanning tree obtained by cutting the appropriate joints of the closed loops of the system at hand. For each subsystem, unconstrained Newton-Euler equations of motion are systematically reduced to a minimal set in terms of the Lagrange multipliers representing the constraint wrenches at the cut joints and the driving torques/forces provided by the actuators. The set of unknown Lagrange multipliers and the driving torques/forces associated to all subsystems are solved in a recursive fashion using the concepts of a determinate subsystem. Next, the constraint forces and moments at the uncut joints of each subsystem are calculated recursively from one body to another. Effectiveness of the proposed algorithm is illustrated using a multiloop planar carpet scraping machine and the spatial RSSR (where R and S stand for revolute and spherical, respectively) mechanism.
31 citations
01 Jan 2005
TL;DR: Kinematic and Dynamic analyses are presented for a 1- DOF (Degree-of-Freedom) pantograph-leg and the main objectives that have been considered are modularity, compactness, light weight and reduced number of DOFs.
Abstract: In this paper Kinematic and Dynamic analyses are presented for a 1- DOF (Degree-of-Freedom) pantograph-leg. The main objectives that have been considered to achieve a walking operation are modularity, compactness, light weight and reduced number of DOFs. A preliminary version of a low-cost biped machine, which is capable of a straight walking with only one actuator, has been built at LARM: Laboratory of Robotics and Mechatronics in Cassino. Experimental tests have been carried out to validate the proposed model and to test the practical feasibility of the leg design.
23 citations
TL;DR: In this paper, a decomposition of the generalized inertia matrix of an n-link serial manipulator is used for the simulation of industrial manipulators which are mainly of serial type, based on the application of Gaussian elimination rules to the recursive expressions of the elements of the inertia matrix that are obtained using the Decoupled Natural Orthogonal Complement matrices.
Abstract: The UDUT – U and D are respectively the upper triangular and diagonal matrices – decomposition of the generalized inertia matrix of an n-link serial manipulator, introduced elsewhere, is used here for the simulation of industrial manipulators which are mainly of serial type. The decomposition is based on the application of the Gaussian elimination rules to the recursive expressions of the elements of the inertia matrix that are obtained using the Decoupled Natural Orthogonal Complement matrices. The decomposition resulted in an efficient order n, i.e., O(n), recursive forward dynamics algorithm that calculates the joint accelerations. These accelerations are then integrated numerically to perform simulation. Using this methodology, a computer algorithm for the simulation of any n degrees of freedom (DOF) industrial manipulator comprising of revolute and/or prismatic joints is developed. As illustrations, simulation results of three manipulators, namely, a three-DOF planar manipulator, and the six-DOF Stanford arm and PUMA robot, are reported in this paper.
22 citations