scholarly journals A Novel Dynamic Three-Level Tracking Controller for Mobile Robots Considering Actuators and Power Stage Subsystems: Experimental Assessment

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4959
Author(s):  
José Rafael García-Sánchez ◽  
Salvador Tavera-Mosqueda ◽  
Ramón Silva-Ortigoza ◽  
Victor Manuel Hernández-Guzmán ◽  
Magdalena Marciano-Melchor ◽  
...  
Keyword(s):  
Dynamic Control ◽  
Current Control ◽  
Mechanical Structure ◽  
Dc Motors ◽  
Tracking Controller ◽  
Medium Level ◽  
Power Stage ◽  
Feasibility Robustness ◽  
And Performance ◽  
High Level

In order to solve the trajectory tracking task in a wheeled mobile robot (WMR), a dynamic three-level controller is presented in this paper. The controller considers the mechanical structure, actuators, and power stage subsystems. Such a controller is designed as follows: At the high level is a dynamic control for the WMR (differential drive type). At the medium level is a PI current control for the actuators (DC motors). Lastly, at the low level is a differential flatness-based control for the power stage (DC/DC Buck power converters). The feasibility, robustness, and performance in closed-loop of the proposed controller are validated on a DDWMR prototype through Matlab-Simulink, the real-time interface ControlDesk, and a DS1104 board. The obtained results are experimentally assessed with a hierarchical tracking controller, recently reported in literature, that was also designed on the basis of the mechanical structure, actuators, and power stage subsystems. Although both controllers are robust when parametric disturbances are taken into account, the dynamic three-level tracking controller presented in this paper is better than the hierarchical tracking controller reported in literature.

scholarly journals Robust Switched Tracking Control for Wheeled Mobile Robots Considering the Actuators and Drivers

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4316 ◽  
Author(s):  
José García-Sánchez ◽  
Salvador Tavera-Mosqueda ◽  
Ramón Silva-Ortigoza ◽  
Victor Hernández-Guzmán ◽  
Jacobo Sandoval-Gutiérrez ◽  
...  
Keyword(s):  
Experimental Results ◽  
Sliding Modes ◽  
Wheeled Mobile Robots ◽  
Differential Drive ◽  
Mechanical Structure ◽  
Dc Motors ◽  
Medium Level ◽  
Power Stage ◽  
High Level ◽  
Better Than

By using the hierarchical controller approach, a new solution for the control problem related to trajectory tracking in a differential drive wheeled mobile robot (DDWMR) is presented in this paper. For this aim, the dynamics of the three subsystems composing a DDWMR, i.e., the mechanical structure (differential drive type), the actuators (DC motors), and the power stage (DC/DC Buck power converters), are taken into account. The proposed hierarchical switched controller has three levels: the high level corresponds to a kinematic control for the mechanical structure; the medium level includes two controls based on differential flatness for the actuators; and the low level is linked to two cascade switched controls based on sliding modes and PI control for the power stage. The hierarchical switched controller was experimentally implemented on a DDWMR prototype via MATLAB-Simulink along with a DS1104 board. With the intention of assessing the performance of the switched controller, experimental results associated with a hierarchical average controller recently reported in literature are also presented here. The experimental results show the robustness of both controllers when parametric uncertainties are applied. However, the performance achieved with the switched controller introduced in the present paper is better than, or at least similar to, performance achieved with the average controller reported in literature.

scholarly journals Tracking Control for Mobile Robots Considering the Dynamics of All Their Subsystems: Experimental Implementation

Complexity ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-18 ◽  
Author(s):  
José Rafael García-Sánchez ◽  
Ramón Silva-Ortigoza ◽  
Salvador Tavera-Mosqueda ◽  
Celso Márquez-Sánchez ◽  
Victor Manuel Hernández-Guzmán ◽  
...  
Keyword(s):  
Hierarchical Level ◽  
Differential Flatness ◽  
Differential Drive ◽  
Mechanical Structure ◽  
Dc Motors ◽  
Experimental Implementation ◽  
Control Scheme ◽  
Medium Level ◽  
Power Stage ◽  
The Mathematical Model

The trajectory tracking task in a wheeled mobile robot (WMR) is solved by proposing a three-level hierarchical controller that considers the mathematical model of the mechanical structure (differential drive WMR), actuators (DC motors), and power stage (DC/DC Buck power converters). The highest hierarchical level is a kinematic control for the mechanical structure; the medium level includes two controllers based on differential flatness for the actuators; and the lowest hierarchical level consists of two average controllers also based on differential flatness for the power stage. In order to experimentally validate the feasibility of the proposed control scheme, the hierarchical controller is implemented via a Σ–Δ-modulator in a differential drive WMR prototype that we have built. Such an implementation is achieved by using MATLAB-Simulink and the real-time interface ControlDesk together with a DS1104 board. The experimental results show the effectiveness and robustness of the proposed control scheme.

Design and Implementation of a Photovoltaic Power System with Bi-Directional Inverter

2013 ◽  
Vol 860-863 ◽  
pp. 128-134
Author(s):  
Yu En Wu ◽  
Chih Chung Wu
Keyword(s):  
Power System ◽  
Current Control ◽  
Core Material ◽  
Current Harmonic ◽  
Grid Connection ◽  
Control Stage ◽  
Power Stage ◽  
And Performance ◽  
Two Stages ◽  
Current Ripple

A PV power system with bi-directional inverter is proposed in this paper. The system is divided into two stages, one is power stage, which contains DC/DC converter and bi-directional inverter, the other is control stage. Both stages control schemes are by a micro-controller dsPIC30F4011. For preventing from high current harmonic caused by the two stages, a predictive current control and modulation principle are designed and operated in high frequency to reduce the current harmonic. The bi-directional inverter can operate in grid-connection (GC) mode or power factor correction (PFC) mode. But the core material of inductance will result in violent current ripple change when the inductor current promoted. So, a gain modulation is used to compensate various inductances used to reduce grid-connection current ripple. Finally, the system is implemented to verify the feasibility and performance of the proposed system.

scholarly journals ANALISIS KINERJA GURU PAI DALAM PENERAPAN METODE PROMPTS PADA PENYANDANG DISABILITAS DI SLB A YAPTI MAKASSAR

2018 ◽  
Vol 7 (2) ◽  
pp. 207
Author(s):  
Nur Aliah Ali ◽  
Novalia Tanasy
Keyword(s):  
Students With Disabilities ◽  
Field Research ◽  
Islamic Education ◽  
Medium Level ◽  
The Subject ◽  
And Performance ◽  
High Level ◽  
Material Factor ◽  
Very High ◽  
A Performance

This study is aim to determine the ability and skills of  Islamic education teachers in applying prompts methods for students with disabilities A or blind students.The specific purpose is to find out the performance of the Islamic education teacher in applying  thetypes of prompts in the form ofverbal prompts, gestural prompts, modeling prompts and physical prompts, beside that this study is determine too the factors that influence the performance of Islamic education teachers  in applying the prompts method to students with disabilities A in SLB A YAPTI Makassar especiallyfor the subject Thaharah, Prayer and Read and write the Qur'an.The research method used is field research with descriptive qualitative and quantitative analysis. In this study, the data collection methods used are observation, interviews, and documentation. The collected data will be analyzed usingan interactive model of Mile and Huberman which includes data reduction, data presentation, verification and conclusion drawing. The type of qualitative data will be analiyzed by deductive-inductive conclusions and quantitative data analyzed using descriptive quantitative in the form of percentages and performance scoring based on the performance scoring table.The research results obtained areThe teacher's performance level are at varying levels. namely moderate, high and very high. NH teachers have a performance at a score of 4 or very high level which means applying all types of prompts in Islamic learning process. RM teachers have a performance at a score of 3 or high level that applies 3 prompts while the KS teacher is on a score of 2 or medium level which only applies two types of prompts namely verbal and physical prompts only. Differences The use of types and indicators applied by Islamic education teachers is different due to material factor, student and teacher characteristics factors.

https://imsciences.edu.pk/files/journals/vol12_2/New%201%20MA.864.pdf

2020 ◽  
Vol 12 (2) ◽  
pp. 19-50 ◽  
Author(s):  
Muhammad Siddique ◽  
Shandana Shoaib ◽  
Zahoor Jan
Keyword(s):  
Organizational Performance ◽  
Structural Equation ◽  
High Performance ◽  
Service Sector ◽  
Performance Outcomes ◽  
Theory And Practice ◽  
Relational Coordination ◽  
Multiple Sources ◽  
And Performance ◽  
High Level

A key aspect of work processes in service sector firms is the interconnection between tasks and performance. Relational coordination can play an important role in addressing the issues of coordinating organizational activities due to high level of interdependence complexity in service sector firms. Research has primarily supported the aspect that well devised high performance work systems (HPWS) can intensify organizational performance. There is a growing debate, however, with regard to understanding the “mechanism” linking HPWS and performance outcomes. Using relational coordination theory, this study examines a model that examine the effects of subsets of HPWS, such as motivation, skills and opportunity enhancing HR practices on relational coordination among employees working in reciprocal interdependent job settings. Data were gathered from multiple sources including managers and employees at individual, functional and unit levels to know their understanding in relation to HPWS and relational coordination (RC) in 218 bank branches in Pakistan. Data analysis via structural equation modelling, results suggest that HPWS predicted RC among officers at the unit level. The findings of the study have contributions to both, theory and practice.

Exploring The Effect of Visual Information Degradation on Human Perception and Performance In A Human-Telerobot System

2020 ◽  
Vol 64 (1) ◽  
pp. 1302-1307
Author(s):  
Richard Stone ◽  
Minglu Wang ◽  
Thomas Schnieders ◽  
Esraa Abdelall
Keyword(s):  
Visual Information ◽  
Human Perception ◽  
Low Level ◽  
Hit Rate ◽  
Word Level ◽  
Level Of Automation ◽  
Significant Difference ◽  
Human Operators ◽  
And Performance ◽  
High Level

Human-robotic interaction system are increasingly becoming integrated into industrial, commercial and emergency service agencies. It is critical that human operators understand and trust automation when these systems support and even make important decisions. The following study focused on human-in-loop telerobotic system performing a reconnaissance operation. Twenty-four subjects were divided into groups based on level of automation (Low-Level Automation (LLA), and High-Level Automation (HLA)). Results indicated a significant difference between low and high word level of control in hit rate when permanent error occurred. In the LLA group, the type of error had a significant effect on the hit rate. In general, the high level of automation was better than the low level of automation, especially if it was more reliable, suggesting that subjects in the HLA group could rely on the automatic implementation to perform the task more effectively and more accurately.

scholarly journals Towards a contemporary player learning in development framework for sports practitioners

2021 ◽  
pp. 174795412110023
Author(s):  
Mark O Sullivan ◽  
Carl T Woods ◽  
James Vaughan ◽  
Keith Davids
Keyword(s):  
Linear Process ◽  
Task Environment ◽  
Coach Education ◽  
Development Framework ◽  
Novel Approach ◽  
Non Linear ◽  
And Performance ◽  
Learning Development ◽  
High Level ◽  
User Friendly

As it is appreciated that learning is a non-linear process – implying that coaching methodologies in sport should be accommodative – it is reasonable to suggest that player development pathways should also account for this non-linearity. A constraints-led approach (CLA), predicated on the theory of ecological dynamics, has been suggested as a viable framework for capturing the non-linearity of learning, development and performance in sport. The CLA articulates how skills emerge through the interaction of different constraints (task-environment-performer). However, despite its well-established theoretical roots, there are challenges to implementing it in practice. Accordingly, to help practitioners navigate such challenges, this paper proposes a user-friendly framework that demonstrates the benefits of a CLA. Specifically, to conceptualize the non-linear and individualized nature of learning, and how it can inform player development, we apply Adolph’s notion of learning IN development to explain the fundamental ideas of a CLA. We then exemplify a learning IN development framework, based on a CLA, brought to life in a high-level youth football organization. We contend that this framework can provide a novel approach for presenting the key ideas of a CLA and its powerful pedagogic concepts to practitioners at all levels, informing coach education programs, player development frameworks and learning environment designs in sport.

Urban network of China from the perspective of population mobility: Three-dimensional co-occurrence of nodes and links

2021 ◽  
pp. 0308518X2199781
Author(s):  
Xinyue Luo ◽  
Mingxing Chen
Keyword(s):  
Three Dimensional ◽  
Geographical Distance ◽  
Two Dimensional ◽  
Population Mobility ◽  
Urban Network ◽  
Urban Networks ◽  
Low Level ◽  
Medium Level ◽  
High Level ◽  
External Connections

The nodes and links in urban networks are usually presented in a two-dimensional(2D) view. The co-occurrence of nodes and links can also be realized from a three-dimensional(3D) perspective to make the characteristics of urban network more intuitively revealed. Our result shows that the external connections of high-level cities are mainly affected by the level of cities(nodes) and less affected by geographical distance, while medium-level cities are affected by the interaction of the level of cities(nodes) and geographical distance. The external connections of low-level cities are greatly restricted by geographical distance.

scholarly journals Vision as oculomotor reward: cognitive contributions to the dynamic control of saccadic eye movements

2021 ◽  
Author(s):  
Christian Wolf ◽  
Markus Lappe
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Visual System ◽  
Dynamic Control ◽  
Saccadic Eye Movements ◽  
Saccade Target ◽  
Cognitive Mechanisms ◽  
Foveal Vision ◽  
Subsequent Behavior ◽  
High Level

AbstractHumans and other primates are equipped with a foveated visual system. As a consequence, we reorient our fovea to objects and targets in the visual field that are conspicuous or that we consider relevant or worth looking at. These reorientations are achieved by means of saccadic eye movements. Where we saccade to depends on various low-level factors such as a targets’ luminance but also crucially on high-level factors like the expected reward or a targets’ relevance for perception and subsequent behavior. Here, we review recent findings how the control of saccadic eye movements is influenced by higher-level cognitive processes. We first describe the pathways by which cognitive contributions can influence the neural oculomotor circuit. Second, we summarize what saccade parameters reveal about cognitive mechanisms, particularly saccade latencies, saccade kinematics and changes in saccade gain. Finally, we review findings on what renders a saccade target valuable, as reflected in oculomotor behavior. We emphasize that foveal vision of the target after the saccade can constitute an internal reward for the visual system and that this is reflected in oculomotor dynamics that serve to quickly and accurately provide detailed foveal vision of relevant targets in the visual field.

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