Study on Trajectory Motion and Computational Analysis of Robot Manipulator

2014 ◽  
Vol 67 (1) ◽  
Author(s):  
Siti Nur Hanisah Umar ◽  
Elmi Abu Bakar
Keyword(s):  
Angular Velocity ◽  
Computational Analysis ◽  
Robot Manipulator ◽  
Lagrange Equation ◽  
Elevation Angle ◽  
Dynamic Interaction ◽  
Simplified Model ◽  
Mathematical Equation ◽  
Connecting Rod ◽  
Over Time

The relation of arm and forearm for arm pitching a ball and bowling game, relation of rotating arm and the connecting rod for crankshaft and any other mechanical system will determine the performance of the system. To obtain the best performance of the system, the study of the dynamic mechanism of the system is essential. In order to study and analyze the dynamic interaction of each link for various applications, robot links manipulator is used as a simplified model for dynamic analysis. The dynamic mathematical equation of robot manipulator is derived by using the Lagrange equation. The elevation angle and angular velocity over time of link one and two is simulated using computerized algorithm. The trajectory motion of both links is illustrated and the relation between both links is determined. The results obtained are then compared with the SimMechanics model. 

scholarly journals Method for Robot Manipulator Joint Wear Reduction by Finding the Optimal Robot Placement in a Robotic Cell

2021 ◽  
Vol 11 (12) ◽  
pp. 5398
Author(s):  
Tomáš Kot ◽  
Zdenko Bobovský ◽  
Aleš Vysocký ◽  
Václav Krys ◽  
Jakub Šafařík ◽  
...  
Keyword(s):  
Angular Velocity ◽  
Dynamic Simulation ◽  
Robot Manipulator ◽  
The Other ◽  
Robotic Arm ◽  
Robotic Cell ◽  
Wear Reduction ◽  
Fixed End ◽  
Robot Placement ◽  
Collaborative Robot

We describe a method for robotic cell optimization by changing the placement of the robot manipulator within the cell in applications with a fixed end-point trajectory. The goal is to reduce the overall robot joint wear and to prevent uneven joint wear when one or several joints are stressed more than the other joints. Joint wear is approximated by calculating the integral of the mechanical work of each joint during the whole trajectory, which depends on the joint angular velocity and torque. The method relies on using a dynamic simulation for the evaluation of the torques and velocities in robot joints for individual robot positions. Verification of the method was performed using CoppeliaSim and a laboratory robotic cell with the collaborative robot UR3. The results confirmed that, with proper robot base placement, the overall wear of the joints of a robotic arm could be reduced from 22% to 53% depending on the trajectory.

Kinematic characteristics of longitudinal double folding wings

2021 ◽  
pp. 1-25
Author(s):  
L. Tiegang ◽  
C. Guoguang ◽  
L. Shuai
Keyword(s):  
Angular Velocity ◽  
Structural Model ◽  
Initial Conditions ◽  
Aerodynamic Force ◽  
Model Simulation ◽  
Lagrange Equation ◽  
Grid Method ◽  
Weapon Systems ◽  
Folding Wing ◽  
Double Folding

ABSTRACT A folding wing is a tactical missile launching device that needs to be miniaturised to facilitate storage, transportation, and launching; save missile and transportation space; and improve the combat capability of weapon systems. This study investigates the aeroelastic characteristics of the secondary longitudinal folding wing during the unfolding process. First, the Lagrange equation is used to establish the structural dynamics model of the folding wing, the kinematics characteristics during the deformation process are analysed, and the unfolding movement of the folding wing is obtained using the dynamic equations in the process. Then, the generalised unsteady aerodynamic force is calculated using the dipole grid method, and the multi-body dynamics equation of the folding wing is obtained. The initial angular velocity required for the deployment of the folding wing is analysed through structural model simulation, and the influence of the initial angular velocity on the opening process is studied. Finally, aeroelastic flutter analysis is performed on the folding wing, and the physical model of the folding wing verified experimentally. Results show that the type of aeroelastic response is sensitive to the initial conditions and the way the folding wing opens.

The Textual Evolution of the Ottoman Şeyhülislams’ Fetvas: A Cross-Corpora Computational Analysis

Der Islam ◽  
2021 ◽  
Vol 98 (2) ◽  
pp. 516-545
Author(s):  
Boğaç Ergene ◽  
Atabey Kaygun
Keyword(s):  
Seventeenth Century ◽  
Computational Analysis ◽  
Computational Techniques ◽  
Close Reading ◽  
Institutional Evolution ◽  
Multiple Forms ◽  
Term Evolution ◽  
Speed Up ◽  
Over Time

Abstract In this article, we use a mix of computational techniques to identify textual shifts in the Ottoman şeyhülislams’ fetvas between the sixteenth and twentieth centuries. Our analysis, supplemented by a close reading of these texts, indicates that the fetvas underwent multiple forms of transformation, a consequence of the institutional evolution of the şeyhülislam’s fetva office (fetvahane) that aimed to speed up and streamline the production of the fetvas: over time, the texts appropriated a more uniform character and came to contain shorter responses. In the compositions of the questions, we identified many “trigger terms” that facilitated reflexive responses independent of the fetvas’ jurisprudential contexts, a tendency that became stronger after the second half of the seventeenth century. In addition, we propose in the article a methodology that measures the relative strengths of textual and conceptual links among the fetva corpora of various Ottoman şeyhülislams. This analysis informs us about possible paths of long-term evolution of this genre of jurisprudential documents.

scholarly journals On rolling friction

2019 ◽  
Vol 485 (3) ◽  
pp. 295-299
Author(s):  
A. P. Ivanov
Keyword(s):  
Friction Coefficient ◽  
Angular Velocity ◽  
Viscous Friction ◽  
Rolling Friction ◽  
The Body ◽  
Normal Velocity ◽  
Contact Conditions ◽  
Combined Motion ◽  
Pure Rolling ◽  
Over Time

The dependence of rolling friction on velocity for various contact conditions is discussed. The principal difference between rolling and other types of relative motion (sliding and spinning) is that the points of the body in contact with the support change over time. Due to deformations, there is a small contact area and, entering into contact, the body points have a normal velocity proportional to the diameter of this area. For describing the dependence of the friction coefficient on the angular velocity in the case of “pure” rolling, a linear dependence is proposed that admits a logical explanation and experimental verification. Under the combined motion, the rolling friction retains its properties, the sliding and spinning friction acquiring the properties of viscous friction.

scholarly journals Analysis of the Wind System Operation in the Optimal Energetic Area at Variable Wind Speed over Time

2019 ◽  
Vol 11 (5) ◽  
pp. 1249 ◽  
Author(s):  
Ciprian Sorandaru ◽  
Sorin Musuroi ◽  
Flaviu Frigura-Iliasa ◽  
Doru Vatau ◽  
Marian Dordescu
Keyword(s):  
Wind Speed ◽  
Angular Velocity ◽  
Optimal Operation ◽  
Wind System ◽  
Optimal Velocity ◽  
Electric Generator ◽  
Wind Speeds ◽  
Power Point ◽  
Variable Wind ◽  
Over Time

Due to high mechanical inertia and rapid variations in wind speed over time, at variable wind speeds, the problem of operation in the optimal energetic area becomes complex and in due time it is not always solvable. No work has been found that analyzes the energy-optimal operation of a wind system operating at variable wind speeds over time and that considers the variation of the wind speed over time. In this paper, we take into account the evolution of wind speed over time and its measurement with a low-power turbine, which operates with no load at the mechanical angular velocity ωMAX. The optimal velocity is calculated. The energy that is captured by the wind turbine significantly depends on the mechanical angular velocity. In order to perform a function in the maximum power point (MPP) power point area, the load on the electric generator is changed, and the optimum mechanical velocity is estimated, ωOPTIM, knowing that the ratio ωOPTIM/ωMAX does not depend on the time variation of the wind speed.

scholarly journals South African consumer sentiment towards marketing: A longitudinal analysis

2001 ◽  
Vol 32 (2) ◽  
pp. 23-33 ◽  
Author(s):  
C. Boshoff ◽  
S. M. Van Eeden
Keyword(s):  
South African ◽  
External Environment ◽  
Consumer Attitudes ◽  
Business Environment ◽  
Dynamic Interaction ◽  
Primary Objective ◽  
Consumer Sentiment ◽  
Marketing Activities ◽  
Buying Behaviour ◽  
Over Time

A constant interaction occurs between the firm, its markets and the variables in the business environment. This dynamic interaction ensures that changes in the environment continuously exert an influence on consumer attitudes and sentiment and how consumers react to and perceive the marketing of products and services.The primary objective of this longitudinal study is to measure South African consumer sentiment towards marketing and to compare the results with previous studies done in 1990 and 1994. Secondary objectives include an investigation to establish to what extent this sentiment towards marketing is influenced by demographic variables.Although the marketing index decreased during the period 1990 to 1994, it improved dramatically during the period 1994 to 1999. In contrast to the previous studies it was established that demographic factors had no significant influence on the sentiment towards marketing in this study.As it is generally acknowledged that attitudes influence actual buying behaviour, marketers need to be aware that attitudes and sentiment toward marketing and marketing activities can change over time and proactive steps need to be taken to ensure that sentiment remains positive regardless of the changes in the external environment.

Smart Utility Pigs Used to Determine and Monitor Pipeline Out-of-Straightness, With Specific Reference to Inspection of BP Alaska’s 10” Northstar Crude Oil Pipeline

2004 ◽  
Author(s):  
Bob Snodgrass ◽  
David Moore ◽  
Barry Nicholson
Keyword(s):  
Angular Velocity ◽  
Crude Oil ◽  
Specific Reference ◽  
Oil Pipeline ◽  
Thermal Changes ◽  
Pipeline Failure ◽  
Over Time

Through necessity many pipelines and flowlines are required to operate under conditions where their position may be displaced over time. Such movements can occur for a wide variety of reasons, but are most commonly associated with either movement of the physical surroundings of the pipeline causing movement of the pipeline itself, and/or thermal changes in the pipeline causing expansion and contraction. Displacements as described result in the pipeline experiencing increased levels of strain at local out-of-straightness events, potentially resulting in pipeline failure. The ability to measure and monitor pipeline displacements, in particular identifying specific regions of out-of-straightness, is valuable to both the existing pipeline operator who wants to operate their assets safely, and also to the pipeline designer who is able to design future pipelines with the knowledge that such monitoring capabilities exist. Smart Utility Pig technology measures the longitudinal shape of a pipeline using an onboard accelerometer and angular velocity sensors. The data logged by these instruments allows out-of-straightness features to be identified and profiles of the vertical and horizontal shape of each to be calculated. This paper presents an overview of the requirements for such Smart Utility Pig technology, and details of out-of-straightness measurement applications. In particular, projects are identified where the technology has been deployed in such a role, including specific reference to BP Alaska’s 10” Northstar crude oil pipeline.

A Simplified Model of Inertial Navigation System for Underground Pipeline Track Instrument

2012 ◽  
Vol 542-543 ◽  
pp. 895-900 ◽  
Author(s):  
Yong Quan Zhang ◽  
Gui Ying Lu ◽  
Xiao Ming Wu
Keyword(s):  
Angular Velocity ◽  
Basic Principle ◽  
Inertial Navigation System ◽  
Inertial Navigation ◽  
Measurement Instrument ◽  
Simplified Model ◽  
Mathematics Model ◽  
Underground Pipeline ◽  
Rolling Angle ◽  
Accuracy Requirement

Based on the analysis of the basic principle of traditional inertial navigation technology, this paper puts forward a kind of simplified model of the track measurement which applies to underground pipeline. The model using structures of half-strap-down stable platform that composes of a single axis gyro, two accelerometers and pulse taximeter, by measuring angular velocity of pipeline azimuth, pitching angle, platform rolling angle and pipeline length, combined with self-actuated research space track, work out the mathematics model, eventually work out the space track of the underground pipeline. The experiment proves that the underground pipeline track measurement instrument which is designed based on the simplified model, can meet the accuracy requirement of the no-dig project on track measurement, and the equipment’s operation is stable and reliable.

A Numerical Approach for Simulating a Self-Contacted Elastic Rod

2014 ◽  
Vol 941-944 ◽  
pp. 2336-2340
Author(s):  
Gong Xi Wang ◽  
Wei Jia Zhao
Keyword(s):  
Topological Structure ◽  
Lagrange Equation ◽  
Numerical Approach ◽  
Simplified Model ◽  
State Variables ◽  
Challenging Problem ◽  
Elastic Rod ◽  
Euler Parameters ◽  
Numerical Examples ◽  
Cosserat Rod

A challenging problem in the numerical simulation of a self-contacted elastic rod is the change of topological structure during the contacting process. In this article, a numerical approach is introduced to simulate a self-contacted Cosserat rod. By introducing the angular velocity and Euler parameters as the state variables, an improved Lagrange equation is introduced. A finite element method is built to deal with the simplified model, and numerical examples are given.

scholarly journals Design and Simulation of Liftable Crawler Chassis for Combine Harvester

2018 ◽  
Vol 8 ◽  
pp. 1476-1487
Author(s):  
Jing Bo ◽  
Xu Lizhang
Keyword(s):  
Angular Velocity ◽  
Hydraulic Cylinder ◽  
Virtual Prototype ◽  
Prototype Model ◽  
Connecting Rod ◽  
Angle Variation ◽  
Adams Software ◽  
Combine Harvester ◽  
Left And Right

Aiming at the needs of field operations in different deep mud, a liftable crawler chassis based on the connecting rod arm mechanism was designed, including the chassis upper frame, lifting mechanism, hydraulic cylinder, limit mechanism, left and right walking system. In the ADAMS software, a virtual prototype model of the lifting and lowering chassis is established. The angle variation of the frame on the chassis relative to the ground and the angular velocity and acceleration of each lifting rod were simulated and analyzed. These rules met the chassis lifting adjustment requirements during the harvester operation.

Sign in / Sign up

Export Citation Format

Share Document