A Unified Optimization Framework and New Set of Performance Metrics for Robot Leg Design

This paper investigates how the passive adaptability of an underactuated robot leg to uneven terrain is affected by variations in design parameters. In particular, the ratio between the joint torques, the ratio between the link lengths, and the initial joint rest angles are varied to determine configurations that allow for maximum terrain roughness adaptability while minimizing the transmission of disturbance forces to the body. The results show that a proximal/distal joint torque coupling ratio of 1.58, proximal/distal leg length ratio of 0.5, and an initial proximal joint angle of −49 degrees maximize the terrain variability over which the robot can remain stable by exerting a near-constant vertical reaction force while minimizing lateral force and moment disturbances. In addition, the spring stiffness ratio allows for a tradeoff to be made between the different performance metrics.

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A Planning and Optimization Framework for Ultra Dense Cellular Deployments

Mobile Information Systems ◽

10.1155/2017/9242058 ◽

2017 ◽

Vol 2017 ◽

pp. 1-17 ◽

Cited By ~ 6

Author(s):

David González González ◽

Edward Mutafungwa ◽

Beneyam Haile ◽

Jyri Hämäläinen ◽

Héctor Poveda

Keyword(s):

Bandwidth Allocation ◽

Performance Metrics ◽

Network Planning ◽

Performance Comparison ◽

Base Stations ◽

System Capacity ◽

Small Cells ◽

Demand Distribution ◽

Optimization Framework ◽

The Impact

To accommodate the ever-expanding wireless data traffic volumes, mobile network operators are complementing their macrocellular networks by deploying low-power base stations (or small cells) to offload traffic from congested macrocells and to reuse spectrum. To that end, Ultra Dense Network (UDN) deployments provide means to aggressively reuse spectrum, thus providing significant enhancements in terms of system capacity. However, these deployments entail several challenges, including the increased complexity in network planning and optimization. In this paper, we propose a versatile optimization framework for planning UDN deployments. The planning and optimization framework is underpinned by metrics that consider scalability in terms of number of users, cost of densification, and fairness. The proposed methodology is evaluated using a real-world UDN planning case. The numerical results expose a number of interesting insights, including the impact of different bandwidth allocation strategies and spatial service demand distribution on the performance of various network topologies. Specifically, we provide a performance comparison of the optimized UDN topologies versus random (unplanned), regular grid, and heuristically derived UDN topologies. This comparison further underlines the need for flexible network planning and optimization frameworks as different operator performance metrics of interest may require different radio access networks configurations.

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Multi-Objective Optimization Methods for Designing Low-Carbon Concrete Mixtures

Frontiers in Materials ◽

10.3389/fmats.2021.680895 ◽

2021 ◽

Vol 8 ◽

Author(s):

M.A. DeRousseau ◽

J.R. Kasprzyk ◽

W.V. Srubar

Keyword(s):

Service Life ◽

Performance Metrics ◽

Simulation Optimization ◽

Design Tool ◽

Concrete Mixture ◽

Low Carbon ◽

Local Conditions ◽

Optimization Framework ◽

Life Conditions ◽

Concrete Mixtures

Concrete mixtures are complex material systems with a multitude of characteristics that decision-makers may deem important. These characteristics can include economic, environmental, mechanical, and durability-related properties of a concrete mixture. However, traditional concrete mixture design typically employs long-standing heuristics, which satisfy requirements for physical characteristics but are unable to minimize specific characteristics, such as the cost or carbon footprint of the concrete mixture. This work considers these performance characteristics by implementing simulation-optimization as a new paradigm for designing concrete mixtures. The utility of the simulation-optimization framework is tested for several concrete design case studies that simultaneously consider compressive strength, embodied carbon, service life, and cost. Results from these scenarios demonstrate that the local conditions of the case study dictate the most important parameters of the simulation-optimization (i.e., relative constituent costs, in situ service-life conditions). Out of all other parameters, constituent cost and service-life conditions impact the set of optimal concrete mixture designs in terms of the types and quantities of mixture ingredients that are utilized. We present a simulation-optimization framework that is demonstrated herein to be a holistic design tool that allows designers to quantify and visualize tradeoffs between critical concrete performance metrics. Such a tool can be used to precision-tailor low-carbon concrete mixtures to the exact preferences of the designer.

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HUMANOID ROBOT LEG DESIGN

10.26678/abcm.cobem2019.cob2019-1595 ◽

2019 ◽

Author(s):

Thiago Tonaco ◽

Daniela Vacarini de Faria ◽

Caroline Silva ◽

Marcos Maximo ◽

Mariano Arbelo

Keyword(s):

Humanoid Robot ◽

Robot Leg ◽

Leg Design

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Linkage Design and Optimisation of a Hexapod Walking Robot Used For Surveillance

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.k1743.0981119 ◽

2019 ◽

Vol 8 (11) ◽

pp. 705-708

Keyword(s):

Basic Structure ◽

Walking Robots ◽

Robot Design ◽

Hexapod Robot ◽

Walking Robot ◽

Walking Gait ◽

Linkage Design ◽

Robot Leg ◽

Leg Design ◽

Basic Movement

The technological advancements at the global level have put in a large demand for walking robots in various industrial and domestic applications. The aim of the paper is to develop a Hexapod (robot with six legs) walking robot that is capable of performing basic movement, such as walking forward and backward, carry payloads and used as a surveillance device. A novel robot leg design has been created with Autodesk Fusion 360, linkage mechanisms of the robot leg is determined by using Linkage 2.0 software. Stress and displacement analysis was done in Autodesk fusion360 software in order to determine whether it can hold the self-weight of the robot and the desired payload to carry the surveillance purpose (i.e. medicine, water, blood etc.). Considering all the possibilities final optimized Hexapod robot design is created using Autodesk Fusion 360 software. Mainly, the undertaken design outline takes into account the fundamental features, such as basic structure, motion planning, payload and walking gait. Fabrication of Hexapod robot parts was completed using additive manufacturing technology FDM process.

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