scholarly journals Robotic Localization Based on Planar Cable Robot and Hall Sensor Array Applied to Magnetic Capsule Endoscope

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5728 ◽  
Author(s):  
Min-Cheol Kim ◽  
Eui-Sun Kim ◽  
Jong-Oh Park ◽  
Eunpyo Choi ◽  
Chang-Sei Kim
Keyword(s):  
Parallel Robot ◽  
Capsule Endoscope ◽  
Hall Effect Sensor ◽  
Sensor Module ◽  
Arbitrary Position ◽  
Single Sensor ◽  
Space Expansion ◽  
Robotic Sensing ◽  
The Given ◽  
Lm Algorithm

Recently an active locomotive capsule endoscope (CE) for diagnosis and treatment in the digestive system has been widely studied. However, real-time localization to achieve precise feedback control and record suspicious positioning in the intestine is still challenging owing to the limitation of capsule size, relatively large diagnostic volume, and compatibility of other devices in clinical site. To address this issue, we present a novel robotic localization sensing methodology based on the kinematics of a planar cable driven parallel robot (CDPR) and measurements of the quasistatic magnetic field of a Hall effect sensor (HES) array. The arrangement of HES and the Levenberg-Marquardt (LM) algorithm are applied to estimate the position of the permanent magnet (PM) in the CE, and the planar CDPR is incorporated to follow the PM in the CE. By tracking control of the planar CDPR, the position of PM in any arbitrary position can be obtained through robot forward kinematics with respect to the global coordinates at the bedside. The experimental results show that the root mean square error (RMSE) for the estimated position value of PM was less than 1.13 mm in the X, Y, and Z directions and less than 1.14° in the θ and φ orientation, where the sensing space could be extended to ±70 mm for the given 34 × 34 mm2 HES array and the average moving distance in the Z-direction is 40 ± 2.42 mm. The proposed method of the robotic sensing with HES and CDPR may advance the sensing space expansion technology by utilizing the provided single sensor module of limited sensible volume.

Mathematical model of the artificial muscle with two actuators

2020 ◽  
pp. 095440622094156
Author(s):  
Ljubinko B Kevac ◽  
Mirjana M Filipovic ◽  
Ana M Djuric
Keyword(s):  
Mathematical Model ◽  
Control Structure ◽  
Artificial Muscle ◽  
Parallel Robot ◽  
Simulation Results ◽  
Proportional Derivative Controller ◽  
Definition Of ◽  
The Mathematical Model ◽  
The Given ◽  
Very High

Characteristic construction of cable-suspended parallel robot of artificial muscle, which presents an artificial forearm, is analyzed and synthesized. Novel results were achieved and presented. Results presented in this paper were initially driven to recognize and mathematically define undefined geometric relations of the artificial forearm since it was found that they strongly affect the dynamic response of this system. It gets more complicated when one has more complex system, which uses more artificial muscle subsystems, since these subsystems couple and system becomes more unstable. Unmodeled or insufficiently modeled dynamics can strongly affect the system’s instability. Because of that, the construction of this system and its new mathematical model are defined and presented in this paper. Generally, it can be said that the analysis of geometry of selected mechanism is the first step and very important step to establish the structural stability of these systems. This system is driven with two actuators, which need to work in a coordinated fashion. The aim of this paper is to show the importance of the geometry of this solution, which then strongly affects the system’s kinematics and dynamics. To determine the complexity of this system, it was presumed that system has rigid cables. Idea is to show the importance of good defined geometry of the system, which gives good basis for the definition of mathematical model of the system. Novel program package AMCO, artificial muscle contribution, was defined for the validation of the mathematical model of the system and for choice of its parameters. Sensitivity of the system to certain parameters is very high and hence analysis of this system needs to be done with a lot of caution. Some parameters are very influential on the possible implementation of the given task of the system. Only after choosing the parameters and checking the system through certain simulation results, control structure can be defined. In this paper, proportional–derivative controller was chosen.

scholarly journals A Novel Three-Loop Parallel Robot With Full Mobility: Kinematics, Singularity, Workspace, and Dexterity Analysis

2017 ◽  
Vol 9 (5) ◽  
Author(s):  
Wei Li ◽  
Jorge Angeles
Keyword(s):  
High Speed ◽  
Screw Theory ◽  
Parallel Robot ◽  
Simple Expression ◽  
Parallel Robots ◽  
Forward Displacement ◽  
Design Variables ◽  
The Subject ◽  
Stewart Gough Platform ◽  
The Given

A novel parallel robot, dubbed the SDelta, is the subject of this paper. SDelta is a simpler alternative to both the well-known Stewart–Gough platform (SGP) and current three-limb, full-mobility parallel robots, as it contains fewer components and all its motors are located on the base. This reduces the inertial load on the system, making it a good candidate for high-speed operations. SDelta features a symmetric structure; its forward-displacement analysis leads to a system of three quadratic equations in three unknowns, which admits up to eight solutions, or half the number of those admitted by the SGP. The kinematic analysis, undertaken with a geometrical method based on screw theory, leads to two Jacobian matrices, whose singularity conditions are investigated. Instead of using the determinant of a 6 × 6 matrix, we derive one simple expression that characterizes the singularity condition. This approach is also applicable to a large number of parallel robots whose six actuation wrench axes intersect pairwise, such as all three-limb parallel robots whose limbs include, each, a passive spherical joint. The workspace is analyzed via a geometric method, while the dexterity analysis is conducted via discretization. Both show that the given robot has the potential to offer both large workspace and good dexterity with a proper choice of design variables.

scholarly journals Calculation of fracture mechanic parameters via FEM for some cracked plates under different loads

2006 ◽  
Vol 28 (2) ◽  
pp. 83-93 ◽  
Author(s):  
Ngo Huong Nhu ◽  
Nguyen Truong Giang
Keyword(s):  
Inclined Crack ◽  
Gravity Dams ◽  
Element Analysis ◽  
Cracked Plates ◽  
Failure State ◽  
The Finite Element Analysis ◽  
Arbitrary Position ◽  
Characteristic Values ◽  
The Given ◽  
Good Agreement

This paper describes some results in analyzing cracked plates via FEM based on the procedures in CASTEM 2000 [1]. The basic methods for computing the crack parameters by the finite element analysis are presented. Some programs written by GIBIAN languages to solve problems for cracked plates are given. In possible cases, the numerical results are composed with analytical solution or testing result that gives a good agreement. The influence of plate configurations, the crack length, the external load type on the crack characteristic values are considered. The numerical analysis for inclined crack at angle and in arbitrary position of plate, the crack at hole in the plate, the crack of gravity dams are realized. The given results and programs can be applied to practical problems for controlling the brittle failure state of a structure.

Kinematic uncertainty analysis of a cable-driven parallel robot based on an error transfer model

2021 ◽  
pp. 1-23
Author(s):  
Jun Gao ◽  
Bin Zhou ◽  
Bin Zi ◽  
Sen Qian ◽  
Ping Zhao
Keyword(s):  
Uncertainty Analysis ◽  
Kinematic Model ◽  
Evidence Theory ◽  
Parallel Robot ◽  
Fast Response ◽  
Inverse Kinematic ◽  
Parallel Robots ◽  
Transfer Model ◽  
The Given ◽  
Error Transfer

Abstract Cable-driven parallel robots (CDPRs) are a kind of mechanism with large workspace, fast response, and low inertia. However, due to the existence of fixed pulleys, it is unavoidable to bring uncertain cable lengths and lead to pose errors of the end-effector (EE). The inverse kinematic model of a CDPR for picking up medicines is established by considering radii of fixed pulleys. The influence of radii of fixed pulleys on errors of cable lengths is explored. Error transfer model of the CPDR is constructed, and uncertain sources of cable lengths are analyzed. Based on evidence theory and error transfer model, an evidence theory-based uncertainty analysis method (ETUAM) is presented. The structural performance function for kinematic response is derived based on error transfer model. Belief and plausibility measures of joint focal elements under the given threshold are obtained. Kinematic error simulations show that errors of cable lengths become larger with the increase of radii of fixed pulleys. Compared with the vertex method and Monte Carlo method, numerical examples demonstrate the accuracy and efficiency of the ETUAM when it comes to the kinematic uncertainty analysis of the CDPR.

Research on Rolling Parallel Robot With Hydraulic Driven Antiparallelogram Chain

2017 ◽  
Vol 9 (1) ◽  
Author(s):  
Haikuo Shen ◽  
Kaihua Zhang ◽  
Afsoon Nejati
Keyword(s):  
Hydraulic System ◽  
Center Of Mass ◽  
Kinematic Model ◽  
Experimental System ◽  
Experimental Tests ◽  
Parallel Robot ◽  
Rapid Response ◽  
Rolling Motion ◽  
Rolling Locomotion ◽  
The Given

Aiming at acquiring large deformation capability, powerful strength output, rapid response, and flexible locomotion, a novel three degrees-of-freedoms (DOFs) rolling parallel robot is proposed. This robot adopts the parallel mechanism, and its structure can guarantee the stiffness of the robot. The large capability of deformation can be obtained by taking advantage of the antiparallelogram mechanism with an enlarging mechanism of extension ratio. Hydraulic actuation is used for the telescopic input, which can increase the locomotion flexibility and the strength output of the robot. Rolling motion of the robot can be reached through planning and controlling the relations between the center of mass (CM) of the robot and the supporting region. The mechanical construction and configuration of the robot are described, the rolling gaits are planned, and the optimal locomotion law is given. Based on the law, the kinematic model of the robot is created. The kinematic model is validated by the given numerical example. The locomotion feasibility of two locomotion periods is analyzed. A set of experimental tests on the hydraulic system and the robotic system are performed. Results of four rolling experiments verify the reliability of the experimental system and the rapid response capability and also verify the validity and feasibility of the theoretical analysis and the rolling locomotion.

scholarly journals A Multimodal, Adjustable Sensitivity, Digital 3-Axis Skin Sensor Module

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3128
Author(s):  
Alexis Carlos Holgado ◽  
Tito Pradhono Tomo ◽  
Sophon Somlor ◽  
Shigeki Sugano
Keyword(s):  
Magnetic Field ◽  
Shear Force ◽  
Normal Force ◽  
Force Sensing ◽  
Capacitive Sensing ◽  
Hall Effect Sensor ◽  
Proximity Detection ◽  
Flexible Material ◽  
Sensor Module ◽  
Proximity Sensing

This paper presents major improvements to a multimodal, adjustable sensitivity skin sensor module. It employs a geomagnetic 3-axis Hall effect sensor to measure changes in the position of a magnetic field generated by an electromagnet. The electromagnet is mounted on a flexible material, and different current values can be supplied to it, enabling adjustments to the sensitivity of the sensor during operation. Capacitive sensing has been added in this iteration of the module, with two sensing modalities: “pre-touch” detection with proximity sensing and normal force capacitive sensing. The sensor has been designed to be interconnected with other sensor modules to be able to cover large surfaces of a robot with normal and shear force sensing and object proximity detection. Furthermore, this paper introduces important size reductions of the previous sensor design, calibration results, and further analysis of other sensor characteristics.

scholarly journals Determination of Workspaces and Intersections of Robot Links in a Multi-Robotic System for Trajectory Planning

2021 ◽  
Vol 11 (11) ◽  
pp. 4961
Author(s):  
Laxmidhar Behera ◽  
Larisa Rybak ◽  
Dmitry Malyshev ◽  
Elena Gaponenko
Keyword(s):  
Minimum Distance ◽  
Parallel Robot ◽  
Robotic System ◽  
Structural Elements ◽  
Mobile Platforms ◽  
Safe Navigation ◽  
Serial Robots ◽  
The Given ◽  
Technological Area

One of the problems in the development of multi-robotic systems is the safe navigation of a group of robots. To solve it, the restrictions imposed by the structural elements of its agents are determined. The article presents a multi-robotic system consisting of parallel and serial robots installed on mobile platforms. The parallel robot is made based on a tripod with the ability to rotate the robot’s base relative to the horizontal axis. The analysis of its working and technological area is carried out, taking into account singularity zones. The developed algorithms for determining the workspaces are based on deterministic methods for approximating the set of solutions to systems of nonlinear inequalities. In this case, restrictions in spaces of different coordinates are presented in the form of n-dimensional boxes. Approaches to solving two problems are proposed to determine the possible intersection of links for the collaborative performance of tasks by a multi-robotic system. The first task is to determine the intersection of the links for the given positions and the relative position of the manipulators. The second is in determining the minimum distance between the technological areas of manipulators, which consist of the workspace and all possible positions of the intermediate links.

Personal Problem Solving of Partners in Divorce Proceedings

2015 ◽  
Vol 36 (1) ◽  
pp. 82-103 ◽  
Author(s):  
Tereza Soukupova ◽  
Petr Goldmann
Keyword(s):  
Gender Differences ◽  
Problem Solving ◽  
Thematic Apperception Test ◽  
Scoring Systems ◽  
Personal Control ◽  
Personality Characteristics ◽  
Personal Problem ◽  
Thematic Apperception ◽  
And Gender ◽  
The Given

Abstract. The Thematic Apperception Test is one of the most frequently administered apperceptive techniques. Formal scoring systems are helpful in evaluating story responses. TAT stories, made by 20 males and 20 females in the situation of legal divorce proceedings, were coded for detection and comparison of their personal problem solving ability. The evaluating instrument utilized was the Personal Problem Solving System-Revised (PPSS-R) as developed by G. F. Ronan. The results indicate that in relation to card 1, men more often than women saw the cause of the problem as removable. With card 6GF, women were more motivated to resolve the given problem than were men, women had a higher personal control and their stories contained more optimism compared to men’s stories. In relation to card 6BM women, more often than men, used emotions generated from the problem to orient themselves within the problem. With card 13MF, the men’s level of stress was less compared to that of the women, and men were more able to plan within the context of problem-solving. Significant differences in the examined groups were found in those cards which depicted significant gender and parental potentials. The TAT can be used to help identify personality characteristics and gender differences.

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