scholarly journals Dynamic research and analysis for a wheel-legged harvester chassis during tilting process

2019 ◽  
Vol 11 (6) ◽  
pp. 168781401985545
Author(s):  
Zhilong Li ◽  
Jinhao Liu ◽  
Sun Zhibo ◽  
Chunzhan Yu
Keyword(s):  
Dynamic Model ◽  
Screw Theory ◽  
Kinematic Model ◽  
The Other ◽  
Average Error ◽  
Theory Method ◽  
Model Simulations ◽  
Process Dynamic ◽  
Lagrange’S Equation ◽  
Actual Motion

This article aims to analyze the dynamic tilting characteristics of a four-wheel-legged harvester chassis. In order to achieve the pose and position of the chassis, kinematic model of a four-wheel-legged harvester chassis was established by the screw theory method. After analyzing the actual motion of the chassis during tilting process, dynamic tilting model of the wheel-legged articulated steering chassis was achieved based on the Lagrange’s equation. To prove the accuracy of the dynamic model, simulations of the chassis was conducted under ADAMS environment. Three series of comparisons showed that results between simulations and calculations were highly consistent. Both results showed that lifting the tilting side wheel-legs, shortening the other side legs, and steering to the tilting side could help prevent tilting of the chassis. Lifting the tilting side wheel-legs was proved to be more efficient than shortening that of the other sides. Average error of the change rates between simulations and calculations were 2.4%, 0.67%, and 2.75%.

scholarly journals Analysis and control for a new reconfigurable parallel mechanism

2020 ◽  
Vol 17 (5) ◽  
pp. 172988142093132
Author(s):  
Guanyu Huang ◽  
Dan Zhang ◽  
Hongyan Tang ◽  
Lingyu Kong ◽  
Sumian Song
Keyword(s):  
Dynamic Model ◽  
Pid Controller ◽  
Parallel Mechanism ◽  
Screw Theory ◽  
Sliding Mode ◽  
Kinematic Model ◽  
Inverse Kinematic ◽  
Loop Equation ◽  
Lagrange Formulation ◽  
And Control

This article proposes a new reconfigurable parallel mechanism using a spatial overconstrained platform. This proposed mechanism can be used as a machine tool. The mobility is analyzed by Screw Theory. The inverse kinematic model is established by applying the closed-loop equation. Next, the dynamic model of the presented mechanism is established by Lagrange formulation. To control the presented mechanism, some controllers have been used. Based on this dynamic model, the fuzzy-proportion integration differentiation (PID) controller is designed to track the trajectory of the end effector. For each limb, a sliding mode controller is applied to track the position and velocity of the slider. Finally, some simulations using ADAMS and MATLAB are proposed to verify the effectiveness and stability of these controllers.

scholarly journals Kinematic and dynamic modeling of a 3gdl robot for educational purposes

2020 ◽  
pp. 1-7
Author(s):  
Aleyda Irene Reyes-González ◽  
José Luis Ortiz-Simón ◽  
Martha Isabel Aguilera-Hernández ◽  
Gustavo Emilio Rojo-Velázquez
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Model ◽  
Dynamic Modeling ◽  
Kinematic Analysis ◽  
Degrees Of Freedom ◽  
Kinematic Model ◽  
The Other ◽  
Final Position ◽  
Specific Point ◽  
Simulink Model

The following article presents the process to obtain the kinematic and dynamic model of a Cartesian robot with 3 degrees of freedom. The robot that is used was designed for educational purposes, it allows two linear movements and one angular. The kinematic model has two forms, direct and inverse, the first provides the final position of the robot if desired values are given to each of the robot's joints, the second provides the values of the joints if there are desired values for the effector final. On the other hand, the obtaining of the dynamic model is presented in detail, which obtains the torques and forces necessary for the robot to be able to move to a specific point. The procedure includes kinematic analysis using Denavit-Hartenberg parameters and dynamic analysis using Jacobeans. As a result, responses obtained from a Simulink model are presented that show the behavior of the developed models.

Study on the Dynamics on the Brake of Vehicle after the Effects of Deicing Salt

2010 ◽  
Vol 26-28 ◽  
pp. 862-869
Author(s):  
Tao Peng ◽  
Zhi Peng Li ◽  
Chang Shu Zhan ◽  
Xiang Luo ◽  
Qian Wang
Keyword(s):  
Simulation Model ◽  
Dynamic Model ◽  
The Other ◽  
Snow Melting ◽  
Adhesion Coefficient ◽  
Deicing Salt ◽  
Other Hand ◽  
Road Condition ◽  
Braking Distance ◽  
The Relationship

Through analyzing the process of brake, a dynamic model of automobile and a model of the relationship between braking distance and adhesion coefficient were formed; also a simulation calculating model of braking distance was established with the use of Matlab. Finally, a research was done toward the braking distance of a type of a car running on a road after using snow-melting agent. On one hand, with the application of the simulation model which has been established, calculations have been done to the braking distance of Bora vehicles running on roads after using deicing salt; on the other hand, by experiments, Bora vehicles’ braking distance and maximum braking deceleration under the same road condition were measured, meanwhile, the established simulation model was verified.

An Analysis of Competitive Oscillations between Japanese Twin Cities

1989 ◽  
Vol 21 (6) ◽  
pp. 803-816 ◽  
Author(s):  
H Kohsaka
Keyword(s):  
Dynamic Model ◽  
Diffusion Of Innovation ◽  
The Other ◽  
Twin Cities ◽  
Competitive Condition ◽  
Medium Term ◽  
Competitive Position ◽  
Retail Development ◽  
Market Shares ◽  
Strong Competition

In this paper keenly-competing Japanese twin cities are examined and the competitive oscillations occurring between them is analyzed as a typical example of medium-term competitive processes. From an analysis of market shares for annual retail sales of women's and children's clothes it was found that there are certain oscillations between the twin cities. As these oscillations are derived from the strong competition between closely-located twin cities, they are called competitive oscillations. In order to analyze the generation of the competitive oscillations, an attempt to reproduce a strongly competitive condition by constructing a dynamic model of two-centre competition was made. As the twin cities share a large part of their populations, they are under strong competitive conditions in which major retail development at one city produces an absolute loss to the other city. Therefore, the twin cities seesaw through the introduction of innovations such as large shops in order to gain a more advantageous competitive position, resulting in competitive oscillations between them. This finding implies that the introduction of innovation to centres is a competitive device in the medium-term and is consistent with the view that the diffusion of innovation is closely related to the competitive process.

Simulation and Analysis of Swing Motion of Lifting Load System on Rescue Vehicle

2012 ◽  
Vol 538-541 ◽  
pp. 725-729
Author(s):  
Han Ming Liu ◽  
Heng Zhao ◽  
Ning Li
Keyword(s):  
Numerical Simulation ◽  
Theoretical Basis ◽  
Safety Assessment ◽  
Kinematic Model ◽  
Excitation Frequency ◽  
Lagrange’S Equation ◽  
Set Up

In lifting, remoted operated dive vehicle（ROV） may swing with the effect of wave. Based on the general form of Lagrange’s equation, a 3-DOF nonlinear swing motion kinematic model was set up. The kinematic response was studied using methods of numerical simulation. The results demonstrated that the kinematic response depends on the length of cable, lifting speed and excitation frequency. Conclusions drawn from this work can be used for safety assessment and theoretical basis for lifting ROV.

scholarly journals Finding of Hard and Soft Territory in Rental Low-Cost Apartment by Using Grounded Theory Method

2021 ◽  
Author(s):  
Fermanto Lianto ◽  
Lilianny Sigit Arifin ◽  
Y. Basuki Dwisusanto ◽  
Rudy Trisno
Keyword(s):  
Grounded Theory ◽  
Low Cost ◽  
The Other ◽  
Theory Method ◽  
Grounded Theory Method ◽  
Other Hand ◽  
The Family ◽  
Territorial Control

Abstract Sharing a corridor space in a rusunawa could form patterns of adaptation and exemplify the phenomenon of territorial mastery. This research aims to understand the form of this mastery as perceived by the occupants using the Grounded Theory method. The results show a theory of territorial mastery that can be developed from the findings in the field is a new theory of territorial characteristics, based on hard and soft territory. The hard territory is territorial control that is tangible or intangible, fixed or unchanged, and firm, whose existence is clear in a space that can be seen, occupied or controlled and maintained, and recognized by other residents. On the other hand, the soft territory is territorial control that is tangible and intangible, and which allows for flexible and soft shifts because it is an expression of the family and cultural emotions of guyub, so that mastery of the soft territory occurs not only because of tolerance, but also because of the prioritization of the feeling of kinship in living under one roof, and the harmonization of guyub relationships amongst people in a community

scholarly journals Spin Wave Based Approximate 4:2 Compressor

2021 ◽  
Author(s):  
Abdulqader Mahmoud ◽  
Frederic Vanderveken ◽  
Florin Ciubotaru ◽  
Christoph Adelmann ◽  
Said Hamdioui ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Error Rate ◽  
Energy Efficient ◽  
Directional Coupler ◽  
State Of The Art ◽  
The Other ◽  
Average Error ◽  
Majority Gate ◽  
Micromagnetic Simulations ◽  
Average Error Rate

In this paper, we propose an energy efficient SW based approximate 4:2 compressor comprising a 3-input and a 5-input Majority gate. We validate our proposal by means of micromagnetic simulations, and assess and compare its performance with one of the state-of-the-art SW, 45nm CMOS, and Spin-CMOS counterparts. The evaluation results indicate that the proposed compressor consumes 31.5\% less energy in comparison with its accurate SW design version. Furthermore, it has the same energy consumption and error rate as the approximate compressor with Directional Coupler (DC), but it exhibits 3x lower delay. In addition, it consumes 14% less energy, while having 17% lower average error rate than the approximate 45nm CMOS counterpart. When compared with the other emerging technologies, the proposed compressor outperforms approximate Spin-CMOS based compressor by 3 orders of magnitude in term of energy consumption while providing the same error rate. Finally, the proposed compressor requires the smallest chip real-estate measured in terms of devices.

scholarly journals Application of Various Machine Learning Techniques in Predicting Total Organic Carbon from Well Logs

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Osama Siddig ◽  
Ahmed Farid Ibrahim ◽  
Salaheldin Elkatatny
Keyword(s):  
Machine Learning ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
The Other ◽  
Well Logs ◽  
Machine Learning Techniques ◽  
Percentage Error ◽  
Average Error ◽  
Support Vector ◽  
Empirical Correlations

Unconventional resources have recently gained a lot of attention, and as a consequence, there has been an increase in research interest in predicting total organic carbon (TOC) as a crucial quality indicator. TOC is commonly measured experimentally; however, due to sampling restrictions, obtaining continuous data on TOC is difficult. Therefore, different empirical correlations for TOC have been presented. However, there are concerns about the generalization and accuracy of these correlations. In this paper, different machine learning (ML) techniques were utilized to develop models that predict TOC from well logs, including formation resistivity (FR), spontaneous potential (SP), sonic transit time (Δt), bulk density (RHOB), neutron porosity (CNP), gamma ray (GR), and spectrum logs of thorium (Th), uranium (Ur), and potassium (K). Over 1250 data points from the Devonian Duvernay shale were utilized to create and validate the model. These datasets were obtained from three wells; the first was used to train the models, while the data sets from the other two wells were utilized to test and validate them. Support vector machine (SVM), random forest (RF), and decision tree (DT) were the ML approaches tested, and their predictions were contrasted with three empirical correlations. Various AI methods’ parameters were tested to assure the best possible accuracy in terms of correlation coefficient (R) and average absolute percentage error (AAPE) between the actual and predicted TOC. The three ML methods yielded good matches; however, the RF-based model has the best performance. The RF model was able to predict the TOC for the different datasets with R values range between 0.93 and 0.99 and AAPE values less than 14%. In terms of average error, the ML-based models outperformed the other three empirical correlations. This study shows the capability and robustness of ML models to predict the total organic carbon from readily available logging data without the need for core analysis or additional well interventions.

scholarly journals Kinematic Modelling of FES Induced Sit-to-stand Movement in Paraplegia

2017 ◽  
Vol 7 (6) ◽  
pp. 3060
Author(s):  
Mohammed Ahmed ◽  
M. S. Huq ◽  
B. S. K. K. Ibrahim
Keyword(s):  
Dynamic Model ◽  
Initial Phase ◽  
Degrees Of Freedom ◽  
Kinematic Model ◽  
Future Research ◽  
Upper Limbs ◽  
Body System ◽  
Segmental Dynamics ◽  
Sit To Stand ◽  
Kinematic Modelling

FES induced movements from indication is promising due to encouraging results being obtained by scholars. The kinematic model usually constitute the initial phase towards achieving the segmental dynamics of any rigid body system. It can be used to ascertain that the model is capable of achieving the desired goal. The dynamic model builds on the kinematic model and is usually mathematically cumbersome depending on the number of degrees-of-freedom. This paper presents a kinematic model applicable for human sit-to-stand movement scenario that will be used to obtain the dynamic model the FES induced movement in a later study. The study shows that the 6 DOF conceptualized sit-to-stand movement can be achieved conveniently using 4 DOF. The 4 DOF has an additional joint compared to similar earlier works which makes more it accurate and flexible. It is more accurate in the sense that it accommodates additional joint i.e. the neck joint whose dynamics could be captured. And more flexible in the sense that if future research uncover more contributions by the segments it can be easily incorporated including that of other segments e.g. the trunk, neck and upper limbs.

Design and kinematics of a novel double-ring truss deployable antenna mechanism

2021 ◽  
pp. 1-14
Author(s):  
Wen-ao Cao ◽  
Sheng Xi ◽  
Huafeng Ding ◽  
Ziming Chen
Keyword(s):  
Topological Structure ◽  
Screw Theory ◽  
Structural Characteristics ◽  
Kinematic Model ◽  
Structure Design ◽  
Structural Symmetry ◽  
Double Ring ◽  
Joint Axis ◽  
Structure Decomposition ◽  
Topological Scheme

Abstract This paper aims to present the topological structure design and kinematic analysis of a novel double-ring truss deployable satellite antenna mechanism. First, a new topological scheme and a new rectangular prism deployable linkage unit are proposed for constructing the kind of antenna mechanisms. Second, the degree-of-freedom (DOF) of the deployable unit and the antenna mechanism are analyzed based on structure decomposition and screw theory. Third, the kinematic model of the double-ring truss deployable antenna mechanism is established based on its structural characteristics. Finally, a typical numerical example is used to illustrate the effectiveness of the designed mechanism and the established kinematic model. The new double-ring truss deployable antenna mechanism consists of the units with the better structural symmetry, and has simpler joint axis layouts, comparing with the same type of most existing mechanisms.

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