scholarly journals Dimensional Optimization of Multi-legged Climbing Robot for Asteriod Exploration Based on Performance Atlas

2020 ◽  
Author(s):  
Qingpeng Wen ◽  
Jun He ◽  
Feng Gao
Keyword(s):  
Kinematic Model ◽  
Optimization Method ◽  
Efficiency Index ◽  
Stiffness Index ◽  
Climbing Robot ◽  
Transmission Index ◽  
Performance Atlas ◽  
Adhesion Efficiency ◽  
And Performance ◽  
Dimensional Optimization

Abstract Multi-legged climbing robots have appealing applications to extreme terrain on asteroids with the microgravity. The robot usually consists of multiple legs and grippers with hierarchical arrays of microspines. The dimensional optimization of the robot with the complicated structure is still a challenge. This paper proposes a multi-parameter grouping optimization method for the multi- legged climbing robot based on performance atlas. First, the structure of the multi-legged climbing robot is described and the kinematic model is established. Second, four performance evaluation indices of the robot, namely the global conditioning index (GCI), the global stiffness index (GSI), the global transmission index(GTI), and the global adhesion efficiency index (GAEI), are derived from the kinematic equations. Third, 11 dimensional parameters of the robot are catergorized into three groups and the detailed optimization process is poposed. Non-dimensional design spaces of three groups of parameters are established and performance atlases regarding the aforementioned evaluation indices are drawn. Finally, the optimal diemensions of the robot are obtained. Besides, the proposed multi-parameter optimization method can be further applied to other legged robots, and the global adhesion efficiency index can be used to guide the design of other grippers.

Optimal design of an asymmetrical parallel mechanism

2021 ◽  
pp. 095440622199007
Author(s):  
Mengli Wu ◽  
Yue Zhang ◽  
Xianqu Yue ◽  
Dongyang Lv ◽  
Mo Chen ◽  
...  
Keyword(s):  
Superposition Principle ◽  
Optimization Method ◽  
Multi Objective Optimization ◽  
Performance Indices ◽  
Linear Superposition ◽  
Ellipsoid Method ◽  
Multi Objective ◽  
Performance Atlas ◽  
Performance Evaluation Index ◽  
And Performance

Aiming at the aircraft composite skin grinding, a Three-DOF Asymmetrical Mechanism (TAM) is proposed to replace manual grinding. Considering asymmetrical characteristics of the TAM, the linear superposition principle is adopted to derive the total stiffness matrix of the mechanism. The driving force curves of numerical calculation and simulation are almost coincident; thus the correctness of the dynamic model is verified. The global kinematics condition number index is established with the velocity ellipsoid method. Similarly, the global stiffness performance evaluation index is constructed according to the stiffness ellipsoid method. Moreover, a new global acceleration dexterity index is proposed to overcome the limitations of the dynamics ellipsoid method. Based on the above models and performance indices, a new optimization method is proposed which combines both single and multi-objective optimization. Among the method, the multi-objective optimization is carried out with normalized weighted sum algorithm and genetic algorithm. This optimization method can not only improve the convergence speed, but also balance the weight of different performance indices. After optimization, the kinematics, stiffness and dynamics performance are significantly improved by contrast with the initial performance atlas. Therefore, the results indicate the effectiveness of the multi-objective optimization method.

scholarly journals Dimensional Optimization of Multi-legged Climbing Robot for Asteriod Exploration Based on Performance Atlas

2021 ◽  
Keyword(s):  
Full Text ◽  
Climbing Robot ◽  
Performance Atlas ◽  
Dimensional Optimization

Abstract The full text of this preprint has been withdrawn by the authors due to author disagreement with the posting of the preprint. Therefore, the authors do not wish this work to be cited as a reference. Questions should be directed to the corresponding author.

High-Performance Image Filters via Sparse Approximations

2020 ◽  
Vol 3 (2) ◽  
pp. 1-19
Author(s):  
Kersten Schuster ◽  
Philip Trettner ◽  
Leif Kobbelt
Keyword(s):  
High Performance ◽  
Hardware Acceleration ◽  
Optimization Method ◽  
Translation Invariant ◽  
Approximation Quality ◽  
Trade Offs ◽  
Sparse Approximations ◽  
Image Filters ◽  
Good Trade ◽  
And Performance

We present a numerical optimization method to find highly efficient (sparse) approximations for convolutional image filters. Using a modified parallel tempering approach, we solve a constrained optimization that maximizes approximation quality while strictly staying within a user-prescribed performance budget. The results are multi-pass filters where each pass computes a weighted sum of bilinearly interpolated sparse image samples, exploiting hardware acceleration on the GPU. We systematically decompose the target filter into a series of sparse convolutions, trying to find good trade-offs between approximation quality and performance. Since our sparse filters are linear and translation-invariant, they do not exhibit the aliasing and temporal coherence issues that often appear in filters working on image pyramids. We show several applications, ranging from simple Gaussian or box blurs to the emulation of sophisticated Bokeh effects with user-provided masks. Our filters achieve high performance as well as high quality, often providing significant speed-up at acceptable quality even for separable filters. The optimized filters can be baked into shaders and used as a drop-in replacement for filtering tasks in image processing or rendering pipelines.

scholarly journals In-Orbit Operational Parameter Calculation and Performance Optimization in KOMPSAT-6 Synthetic Aperture Radar

2021 ◽  
Vol 13 (12) ◽  
pp. 2342
Author(s):  
Jin-Bong Sung ◽  
Sung-Yong Hong
Keyword(s):  
Synthetic Aperture Radar ◽  
Performance Optimization ◽  
Pulse Repetition Frequency ◽  
Optimization Method ◽  
Synthetic Aperture ◽  
Operational Parameters ◽  
Operational Parameter ◽  
Design Methodologies ◽  
And Performance ◽  
Aperture Radar

A new method to design in-orbit synthetic aperture radar operational parameters has been implemented for the Korean Multi-purpose Satellite 6 mission. The implemented method optimizes the pulse repetition frequency when a satellite altitude changes from its nominal one, so it has the advantage that the synthetic aperture radar performances can satisfy the requirements for the in-orbit operation. Other commanding parameters have been designed to conduct trade-off between those parameters. This paper presents the new optimization method to maintain the synthetic aperture radar performances even in the case of an altitude variation. Design methodologies to determine operational parameters, respectively, at nominal altitude and in orbit are presented. In addition, numerical simulation is presented to validate the proposed optimization and the design methodologies.

scholarly journals A Fast Optimization Method for Reliability and Performance of Cloud Services Composition Application

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Zhao Wu ◽  
Naixue Xiong ◽  
Yannong Huang ◽  
Qiong Gu ◽  
Chunyang Hu ◽  
...  
Keyword(s):  
Cloud Computing ◽  
State Space ◽  
Generating Function ◽  
Performance Optimization ◽  
Optimization Method ◽  
Cloud Services ◽  
Services Composition ◽  
Fast Optimization ◽  
And Performance ◽  
Universal Generating Function

At present the cloud computing is one of the newest trends of distributed computation, which is propelling another important revolution of software industry. The cloud services composition is one of the key techniques in software development. The optimization for reliability and performance of cloud services composition application, which is a typical stochastic optimization problem, is confronted with severe challenges due to its randomness and long transaction, as well as the characteristics of the cloud computing resources such as openness and dynamic. The traditional reliability and performance optimization techniques, for example, Markov model and state space analysis and so forth, have some defects such as being too time consuming and easy to cause state space explosion and unsatisfied the assumptions of component execution independence. To overcome these defects, we propose a fast optimization method for reliability and performance of cloud services composition application based on universal generating function and genetic algorithm in this paper. At first, a reliability and performance model for cloud service composition application based on the multiple state system theory is presented. Then the reliability and performance definition based on universal generating function is proposed. Based on this, a fast reliability and performance optimization algorithm is presented. In the end, the illustrative examples are given.

scholarly journals Static Profiling of Assembly Code Performance and Optimization Effectiveness using Instructions Performed and Program Latency

2019 ◽  
Vol 8 (2S8) ◽  
pp. 1463-1468
Keyword(s):  
Assembly Language ◽  
Optimization Method ◽  
Program Optimization ◽  
Low Level ◽  
Code Performance ◽  
Execution Speed ◽  
The Difference ◽  
And Performance ◽  
High Level ◽  
Optimization And Performance

Software program optimization for improved execution speed can be achieved through modifying the program. Programs are usually written in high level languages then translated into low level assembly language. More coverage of optimization and performance analysis can be performed on low level than high level language. Optimization improvement is measured in the difference in program execution performance. Several methods are available for measuring program performance are classified into static approaches and dynamic approaches. This paper presents an alternative method of more accurately measuring code performance statically than commonly used code analysis metrics. New metrics proposed are designed to expose effectiveness of optimization performed on code, specifically unroll optimizations. An optimization method, loop unroll is used to demonstrate the effectiveness of the increased accuracy of the proposed metric. The results of the study show that measuring Instructions Performed and Instruction Latency is a more accurate static metric than Instruction Count and subsequently those based on it.

Information Technology Spending Association with Organizational Productivity and Performance

2011 ◽  
pp. 89-124 ◽  
Author(s):  
Carlos J. Navarrete ◽  
James B. Pick
Keyword(s):  
Federal Government ◽  
Efficiency Index ◽  
Productivity Index ◽  
Bank Performance ◽  
Operational Cost ◽  
Organizational Productivity ◽  
Bank Efficiency ◽  
Productivity Indices ◽  
And Performance ◽  
The Relationship

This chapter examines the relationship between IT expenditure and bank profitability, efficiency, productivity, and performance for Mexican banks. The principal research method is correlation analysis between IT expenditure and four bank performance indices: a profitability index that combines bank profits, income, operational cost, and financial cost; a performance index that includes credit and bank income market share; a productivity index consisting of the number of employees, branches, and managers; and an efficiency index that includes banks’ operational cost and income. The unit of analysis is the firm. The data are from the 18 banks comprising the Mexican banking industry from 1982–1992, when Mexico’s banks were owned by the federal government. The study’s interpretations are supported by interviews with four bank CIOs and a CEO, in office during the period. The main findings are that bank IT expenditure ratio is positively correlated to bank performance and productivity indices, whereas IT expenditure is not correlated with bank efficiency or profitability indices. There are fluctuations in the strength of correlation during the 11-year period, which are explained. The chapter results not only reject the productivity paradox but also provide insights to explain the paradox and IT contribution to the firm performance.

Ball Drive Configurations and Kinematics for Holonomic Ground Mobility

2017 ◽  
Author(s):  
Biruk A. Gebre ◽  
Kishore Pochiraju
Keyword(s):  
Design Space ◽  
Kinematic Model ◽  
Design Parameters ◽  
Actuation Force ◽  
Confined Spaces ◽  
Naming Convention ◽  
Trade Offs ◽  
Vehicle Velocity ◽  
And Performance ◽  
Selection Of

Holonomic motion is desired for mobile ground robots and vehicles as it provides omnidirectional maneuvering capabilities, which can simplify the task of navigating around obstacles in confined spaces and unstructured environments. Mobility platforms that utilize spherical wheels are gaining popularity and interest due to the agile maneuvering and ground traversal capabilities they enable for mobility platforms. Ball-driven mobility platforms have a rich design space as various design parameters are available that can modify the physical and performance characteristics of the platforms. Various configurations for ball-driven mobility platforms are presented along with a generalized kinematic model that can be used for calculating motor velocities for a desired vehicle velocity. A naming convention is also presented in the paper for differentiating between configurations used for ball-driven mobility platforms. Metrics such as platform footprint, platform stability, and actuation force and efficiency are used to compare the configurations and to highlight some of the trade-offs associated with the selection of a configuration. Promising configurations are highlighted based on the metrics selected for the comparisons.

Design and Performance of 8Slot-12Pole Permanent Magnet Flux Switching Machines for Electric Bicycle Application

2017 ◽  
Vol 8 (1) ◽  
pp. 248 ◽  
Author(s):  
Laili Iwani Jusoh ◽  
Erwan Sulaiman ◽  
Rajesh Kumar ◽  
Fatihah Shafiqah Bahrim
Keyword(s):  
Permanent Magnet ◽  
Power Density ◽  
Single Phase ◽  
Optimization Method ◽  
Structure Design ◽  
Initial Design ◽  
Electric Bicycle ◽  
And Performance ◽  
Low Torque ◽  
Future Work

This paper presents a new design and performance of single phase permanent magnet flux-switching machine (PMFSM) for electric bicycle application. 8Slot-12Pole design machine were choose by analyzing the highest power density value. All active parts such as permanent magnet and armature coil are located on the stator, while the rotor part consists of only single piece iron. PMFSM have a great advantage with robust rotor structure that make it much higher power and applicable for EV application compared to SRM and IPMSM. The design, operating principles, characteristics of torque, and power of this new topology are investigated by JMAG-Designer via a 2D-FEA. Size of motor and volume of PM is designed at 75mm and 80g, respectively. Based on the investigation, it can be concluded that the proposed topology of single phase 8Slot 12Pole PMFSM achieved the target of highest performance of power density, approximately at 0.113W/mm3 with reduced permanent magnet and size of design motor. Due to the low torque performance of this initial design, further works is ongoing to improve the torque performance. In future work, outer rotor PMFSM structure design will be presented and compared with the “Deterministic Optimization Method” to improve the initial design.

scholarly journals An Optimization Framework for Codes Classification and Performance Evaluation of RISC Microprocessors

Symmetry ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 938
Author(s):  
Syed Rameez Naqvi ◽  
Ali Roman ◽  
Tallha Akram ◽  
Majed M. Alhaisoni ◽  
Muhammad Naeem ◽  
...  
Keyword(s):  
Assembly Language ◽  
Optimization Method ◽  
Instruction Set ◽  
Mathematical Performance ◽  
Optimization Framework ◽  
And Performance ◽  
Reduced Instruction Set Computer ◽  
High Level ◽  
The Given ◽  
Primary Contribution

Pipelines, in Reduced Instruction Set Computer (RISC) microprocessors, are expected to provide increased throughputs in most cases. However, there are a few instructions, and therefore entire assembly language codes, that execute faster and hazard-free without pipelines. It is usual for the compilers to generate codes from high level description that are more suitable for the underlying hardware to maintain symmetry with respect to performance; this, however, is not always guaranteed. Therefore, instead of trying to optimize the description to suit the processor design, we try to determine the more suitable processor variant for the given code during compile time, and dynamically reconfigure the system accordingly. In doing so, however, we first need to classify each code according to its suitability to a different processor variant. The latter, in turn, gives us confidence in performance symmetry against various types of codes—this is the primary contribution of the proposed work. We first develop mathematical performance models of three conventional microprocessor designs, and propose a symmetry-improving nonlinear optimization method to achieve code-to-design mapping. Our analysis is based on four different architectures and 324,000 different assembly language codes, each with between 10 and 1000 instructions with different percentages of commonly seen instruction types. Our results suggest that in the sub-micron era, where execution time of each instruction is merely in a few nanoseconds, codes accumulating as low as 5% (or above) hazard causing instructions execute more swiftly on processors without pipelines.

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