scholarly journals Sustainable green networking: exploiting degrees of freedom towards energy-efficient 5G systems

2017 ◽  
Vol 25 (3) ◽  
pp. 951-960 ◽  
Author(s):  
Miao Yao ◽  
Munawwar M. Sohul ◽  
Xiaofu Ma ◽  
Vuk Marojevic ◽  
Jeffrey H. Reed
Keyword(s):  
Energy Efficient ◽  
Degrees Of Freedom ◽  
Green Networking ◽  
5G Systems

scholarly journals Recent Design Optimization Methods for Energy-Efficient Electric Motors and Derived Requirements for a New Improved Method—Part 1

Proceedings ◽  
2018 ◽  
Vol 2 (22) ◽  
pp. 1400
Author(s):  
Johannes Schmelcher ◽  
Max Kleine Büning ◽  
Kai Kreisköther ◽  
Dieter Gerling ◽  
Achim Kampker
Keyword(s):  
Rare Earth ◽  
Design Optimization ◽  
Energy Efficient ◽  
Degrees Of Freedom ◽  
High Efficiency ◽  
Optimization Problems ◽  
Computing Time ◽  
Optimization Methods ◽  
Electric Motors ◽  
Electric Cars

Energy-efficient electric motors are gathering an increased attention since they are used in electric cars or to reduce operational costs, for instance. Due to their high efficiency, permanent-magnet synchronous motors are used progressively more. However, the need to use rare-earth magnets for such high-efficiency motors is problematic not only in regard to the cost but also in socio-political and environmental aspects. Therefore, an increasing effort has to be put in finding the best design possible. The goals to achieve are, among others, to reduce the amount of rare-earth magnet material but also to increase the efficiency. In the first part of this multipart paper, characteristics of optimization problems in engineering and general methods to solve them are presented. In part two, different approaches to the design optimization problem of electric motors are highlighted. The last part will evaluate the different categories of optimization methods with respect to the criteria: degrees of freedom, computing time and the required user experience. As will be seen, there is a conflict of objectives regarding the criteria mentioned above. Requirements, which a new optimization method has to fulfil in order to solve the conflict of objectives will be presented in this last paper.

Kinetostatic Performance Analysis of a Redundantly Driven Parallel Kinematic Manipulator

2014 ◽  
Author(s):  
Michael Lorenz ◽  
Burkhard Corves ◽  
Martin Riedel
Keyword(s):  
Energy Efficiency ◽  
Energy Efficient ◽  
Degrees Of Freedom ◽  
Mathematical Optimization ◽  
Control Methods ◽  
Drive Power ◽  
Maximum Torque ◽  
Torque Distribution ◽  
Mechanical Handling ◽  
Parallel Kinematic

In general the mechanical handling of objects in space is performed by manipulators, whose number of actuators is consistent with the number of required degrees of freedom. In addition, manipulators can be equipped with redundant drives, providing the manipulator with more actuators than the mobility actually requires. Thus, an active distribution of drive torques is enabled. Accordingly, this research intends to analyze the effects of torque distribution in over-actuated manipulators relating to load-optimized and energy-efficient handling. By developing torque distribution strategies the maximum torque levels can be reduced and the required drive power thus be decreased. This results in an increased drive utilization, which improves the energy-efficiency of the handling system. On this basis, an innovative handling concept is analyzed, which represents an over-determined system given the number of actuators. Hence, it is shown that the drive utilization of manipulators can be significantly improved by means of actuation redundancy. For this purpose different mathematical optimization approaches are analyzed, which solve the over-actuated system with defined optimization targets. Here, the optimal torque distribution is found using an algorithm, which minimizes the maximum torque for each object position. The results demonstrate the efficiency of active torque distribution in terms of over-actuated manipulators. For a further approach it is planned to develop control methods including optimized torque distribution strategies in order to improve the performance and the energy efficiency of the entire manipulator.

scholarly journals Energy-Efficient Slithering Gait Exploration for a Snake-Like Robot Based on Reinforcement Learning

2019 ◽  
Author(s):  
Zhenshan Bing ◽  
Christian Lemke ◽  
Zhuangyi Jiang ◽  
Kai Huang ◽  
Alois Knoll
Keyword(s):  
Reinforcement Learning ◽  
Energy Efficient ◽  
Degrees Of Freedom ◽  
Bayesian Optimization ◽  
Control Task ◽  
Flexible Bodies ◽  
Model Free ◽  
Novel Approach ◽  
Wide Range ◽  
Policy Optimization

Similar to their counterparts in nature, the flexible bodies of snake-like robots enhance their movement capability and adaptability in diverse environments. However, this flexibility corresponds to a complex control task involving highly redundant degrees of freedom, where traditional model-based methods usually fail to propel the robots energy-efficiently. In this work, we present a novel approach for designing an energy-efficient slithering gait for a snake-like robot using a model-free reinforcement learning (RL) algorithm. Specifically, we present an RL-based controller for generating locomotion gaits at a wide range of velocities, which is trained using the proximal policy optimization (PPO) algorithm. Meanwhile, a traditional parameterized gait controller is presented and the parameter sets are optimized using the grid search and Bayesian optimization algorithms for the purposes of reasonable comparisons. Based on the analysis of the simulation results, we demonstrate that this RL-based controller exhibits very natural and adaptive movements, which are also substantially more energy-efficient than the gaits generated by the parameterized controller. Videos are shown at https://videoviewsite.wixsite.com/rlsnake .

Sustainable Green Networking and Computing in 5G Systems

2017 ◽  
Vol 24 (4) ◽  
pp. 12-13 ◽  
Author(s):  
Lin Chen ◽  
Lingjie Duan ◽  
Alagan Anpalagan ◽  
Octavia A. Dobre ◽  
Zhisheng Niu
Keyword(s):  
Green Networking ◽  
5G Systems

Recent advances in energy-efficient networks and their application in 5G systems

2015 ◽  
Vol 22 (2) ◽  
pp. 145-151 ◽  
Author(s):  
Gang Wu ◽  
Chenyang Yang ◽  
Shaoqian Li ◽  
Geoffrey Ye Li
Keyword(s):  
Energy Efficient ◽  
Recent Advances ◽  
5G Systems

A Method of Swing Leg Control for a Minimally Actuated Medical Exoskeleton for Individuals With Paralysis

2013 ◽  
Author(s):  
Jason I. Reid ◽  
Michael McKinley ◽  
Wayne Tung ◽  
Minerva Pillai ◽  
H. Kazerooni
Keyword(s):  
Energy Efficient ◽  
Degrees Of Freedom ◽  
Legged Locomotion ◽  
Swing Phase ◽  
Current Medical ◽  
Robotic Systems ◽  
State Dependent ◽  
Early Results ◽  
Natural Energy ◽  
Flexion And Extension

This paper discusses the control of a medical exoskeleton swing leg that has a “passive” (unactuated) knee. Previous work in legged locomotion has demonstrated the feasibility of achieving natural, energy efficient walking with minimally actuated robotic systems. This work will present early results for a medical exoskeleton that only has actuation that powers the flexion and extension of the biological hip. In this work, a hybrid model of the state dependent kinematics and dynamics of the swing leg will be developed and parameterized to yield swing hip dynamics as a function of desired knee flexion dynamics. This model is used to design swing hip motions that control the flexion behavior of the passive swing knee in a human-like manner. This concept was tested by a paraplegic user wearing a new minimally actuated exoskeleton. The presented results show that a human-like swing phase can be achieved with an exoskeleton that has fewer actuated degrees of freedom than current medical exoskeletons.

A General Approach for Dynamic Positioning Weathervane Control

2013 ◽  
Vol 47 (2) ◽  
pp. 31-42 ◽  
Author(s):  
Michel R. Miyazaki ◽  
Eduardo A. Tannuri
Keyword(s):  
Energy Consumption ◽  
Control Theory ◽  
Environmental Conditions ◽  
Energy Efficient ◽  
Degrees Of Freedom ◽  
Control Point ◽  
Effective Control ◽  
Dynamic Positioning ◽  
Control Methods ◽  
Reduce Energy Consumption

AbstractEnergy efficient controllers for dynamic positioning (DP) systems are a possible approach to reduce energy consumption and CO2 emission on large offshore systems. Due to the flexibility of some DP operations, it is possible to change the vessel heading in order to align with the resultant force defined by the environmental conditions, reducing the thrust and power required to keep position, thus increasing station-keeping capability. However, online calculation of the optimum heading may not be possible because of uncertainties about wave and current intensity and direction. Moreover, these factors change through time, and the system must be able to adapt to those changes and to keep the optimum positioning. This paper presents a new methodology to define the heading setpoint based on zero power control theory. This methodology has important advantages over traditional weathervane control methods, such as an effective control of all horizontal degrees of freedom of the vessel and the possibility to define any reference control point, not only points located at the vessel bow.

Research on Dynamic Performance of Independent Metering Control System

2017 ◽  
Author(s):  
Qi Zhong ◽  
Bin Zhang ◽  
Mingjie Niu ◽  
Haocen Hong ◽  
Huayong Yang
Keyword(s):  
Control System ◽  
Energy Efficient ◽  
Degrees Of Freedom ◽  
Dynamic Performance ◽  
Voice Coil Motor ◽  
Pressure Control ◽  
Control Mode ◽  
Fuzzy Pid Control ◽  
Efficient Control ◽  
Valve Control

Compared with traditional valve control systems, the independent metering valve control system (IMVCS) broke down the mechanical connection of the meter-in and meter-out orifices so that it increased the control degrees of freedom. More importantly, it achieved a more energy-efficient control mode for hydraulic system. This paper studied the dynamic characteristics of IMVCS based on fuzzy PID control algorithm. A controller included power amplifier module, voice coil motor (VCM) drive module, data acquisition module and CAN communication module was designed. A SYS/BIOS based embedded operating system was adopted in this controller for fast response. A host computer program based on CAN bus was developed to monitor status of the IMVCS. A series of experiments of displacement control and pressure control have been carried out, and results showed a good dynamic performance and huge potential of energy-efficient control.

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