Optimal design of support parameters for minimum force transmissibility of a flexible rotor based on H∞ and H2 optimization methods

2017 ◽  
Vol 50 (4) ◽  
pp. 671-683 ◽  
Author(s):  
Hamidreza Heidari ◽  
Pedram Safarpour
Keyword(s):  
Optimal Design ◽  
Optimization Methods ◽  
Flexible Rotor ◽  
Force Transmissibility ◽  
Minimum Force ◽  
H2 Optimization

scholarly journals A Comprehensive Study on the Optimal Design of Magnetorheological Dampers for Improved Damping Capacity and Dynamical Adjustability

Actuators ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 64
Author(s):  
Liankang Wei ◽  
Hongzhan Lv ◽  
Kehang Yang ◽  
Weiguang Ma ◽  
Junzheng Wang ◽  
...  
Keyword(s):  
Optimal Design ◽  
Optimization Methods ◽  
Design Stage ◽  
Damping Capacity ◽  
Damping Force ◽  
Simulation And Optimization ◽  
Damping Characteristics ◽  
Hysteretic Characteristics ◽  
Gap Width ◽  
Comprehensive Study

Purpose: We aim to provide a systematic methodology for the optimal design of MRD for improved damping capacity and dynamical adjustability in performing its damping function. Methods: A modified Bingham model is employed to model and simulate the MRD considering the MR fluid’s compressibility. The parameters that describe the structure of MRD and the property of the fluid are systematically examined for their contributions to the damping capacity and dynamically adjustability. A response surface method is employed to optimize the damping force and dynamically adjustable coefficient for a more practical setting related to the parameters. Results: The simulation system effectively shows the hysteretic characteristics of MRDs and shows our common sense understanding that the damping gap width and yoke diameter have significant effects on the damping characteristics of MRD. By taking a typical MRD device setup, optimal design shows an increase of the damping force by 33% and an increase of the dynamically adjustable coefficient by 17%. It is also shown that the methodology is applicable to other types of MDR devices. Conclusion: The compressibility of MR fluid is one of the main reasons for the hysteretic characteristics of MRD. The proposed simulation and optimization methods can effectively improve the MRD’s damping performance in the design stage.

New Indices for Optimal Design of Redundantly Actuated Parallel Manipulators

2016 ◽  
Vol 9 (1) ◽  
Author(s):  
Qinchuan Li ◽  
Ningbin Zhang ◽  
Feibo Wang
Keyword(s):  
Optimal Design ◽  
Degrees Of Freedom ◽  
Parallel Manipulators ◽  
Mean Value ◽  
Transmission Performance ◽  
Transmission Index ◽  
Redundantly Actuated ◽  
Lower Mobility ◽  
Six Dof ◽  
Force Transmissibility

Redundantly actuated parallel manipulators (PMs) receive growing interest due to their reduced singularity and enlarged workspace. This paper proposes new indices for optimal design and analysis of redundantly actuated PMs by evaluating their motion/force transmissibility. First, we proposed a method to extract a multi-DOF (degrees-of-freedom) redundantly actuated PM into several subsidiary one-DOF PMs with two or more actuators by locking some actuators in an ergodic manner. Then, a new index of output transmission performance is proposed by investigating the mean value of the instantaneous power produced by the multiple actuation wrenches and one twist of the moving platform of one-DOF PMs. A local transmission index (LTI) is defined as the minimum value of the index of output and input transmission performance. A global transmission index (GTI) is then established based on the LTI. The proposed LTI and GTI are coordinate-free and have clear physical interpretation. Finally, the validity and universality of the new indices are demonstrated by optimization and analysis of redundantly actuated lower-mobility PMs with extra articulated six-DOF or limited-DOF limbs.

scholarly journals Overview of the Optimal Design of the Electrically Excited Doubly Salient Variable Reluctance Machine

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 228
Author(s):  
Yao Zhao ◽  
Chuanyang Lu ◽  
Dongdong Li ◽  
Xing Zhao ◽  
Fan Yang
Keyword(s):  
Optimal Design ◽  
Optimization Design ◽  
Basic Structure ◽  
Optimization Methods ◽  
Advantages And Disadvantages ◽  
Variable Reluctance ◽  
Reluctance Machine ◽  
Doubly Salient ◽  
New Type ◽  
Salient Variable

The Electrically Excited Doubly Salient Variable Reluctance Machine (EEDSVRM) is a new type of brushless machine designed according to the principle of air gap reluctance change. There is neither permanent magnet steel nor excitation winding on the rotor. The rotor is made of silicon steel sheets, thus the structure of the variable reluctance machine is very simple. There are many optimization methods for this type of machine optimal design, such as novel machine topology optimization, finite element simulation-based optimization, mathematical analysis-based optimization, intelligent algorithm-based optimization, and multiple fusion-based optimization. Firstly, this article introduces the basic structure and working principle of the EEDSVRM and analyzes both its common regularity and individual difference. Then, the different optimization design methods of EEDSVRM are reviewed, the advantages and disadvantages of the different optimization methods are summarized, and the research interests of the optimization design of variable reluctance machines in the future are prospected.

scholarly journals Optimal design of symmetric switching CMOS inverter using symbiotic organisms search algorithm

2020 ◽  
Vol 10 (1) ◽  
pp. 171
Author(s):  
Nihad Dib ◽  
Umar Al-Sammarraie
Keyword(s):  
Optimal Design ◽  
High Speed ◽  
Search Algorithm ◽  
Fitness Function ◽  
Logic Gate ◽  
Optimization Methods ◽  
Optimization Method ◽  
Cmos Inverter ◽  
Symbiotic Organisms Search ◽  
Symbiotic Organisms

This paper investigates the optimal design of symmetric switching CMOS inverter using the Symbiotic Organisms Search (SOS) algorithm. SOS has been recently proposed as an effective evolutionary global optimization method that is inspired by the symbiotic interaction strategies between different organisms in an ecosystem. In SOS, the three common types of symbiotic relationships (mutualism, commensalism, and parasitism) are modeled using simple expressions, which are used to find the global minimum of the fitness function. Unlike other optimization methods, SOS has no parameters to be tuned, which makes it an attractive and easy-to-implement optimization method. Here, SOS is used to design a high speed symmetric switching CMOS inverter, which is considered the most fundamental logic gate. SOS results are compared to those obtained using several optimization methods, like particle swarm optimization (PSO), genetic algorithm (GA), differential evolution (DE), and other ones, available in the literature. It is shown that the SOS is a robust straight-forward evolutionary algorithm that can compete with other well-known advanced methods.

An Efficient Computational Inverse Approach for Optimal Design of Localized Activation and Actuation for Morphing SMP Structures

2012 ◽  
Author(s):  
Shuang Wang ◽  
John C. Brigham
Keyword(s):  
Inverse Problem ◽  
Optimal Design ◽  
Shape Change ◽  
Mechanical Energy ◽  
Optimization Methods ◽  
Future Directions ◽  
Inverse Approach ◽  
Thermally Activated ◽  
Nonlinear Optimization Methods ◽  
Numerical Representations

A strategy is presented to identify the optimal localized activation and actuation for a morphing thermally-activated SMP structure or structural component to obtain a targeted shape change subject to design objectives such as minimal total required energy and time. This strategy combines numerical representations of the SMP structure’s thermo-mechanical behavior subject to activation and actuation with nonlinear optimization methods to efficiently solve the morphing inverse problem that includes minimizing cost functions which address thermal and mechanical energy, morphing time, and damage. The details of this strategy are presented along with simulated examples to display the capabilities and limitations, as well as potential future directions for improving these techniques.

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