scholarly journals Robust Control of Electric Tail Reduction System: Uncertainty and Performance Index

2020 ◽  
Vol 11 (1) ◽  
pp. 260
Author(s):  
Kang Huang ◽  
Chao Ma ◽  
Han Zhao ◽  
Zicheng Zhu
Keyword(s):  
Robust Control ◽  
Performance Index ◽  
Optimization Design ◽  
Control Method ◽  
Optimal Parameter ◽  
Design Method ◽  
Optimization Method ◽  
Control Cost ◽  
Reduction System ◽  
Parameter Optimization Design

The electric tail reduction system of the unmanned helicopter contains uncertainty. To solve this problem, a constraint-following approach was applied to design a novel robust control for uncertain mechanical systems. The dynamic model of the uncertain electric tail reduction system was established by combining the load of the electric tail rotor and the flight state of the helicopter. Based on the Udwadia–Kalaba theory, a robust constraint following the control method was proposed to deal with the uncertainty of the system. In addition, to balance the steady-state performance and control cost of the system, a control parameter optimization design method was proposed to minimize the performance index. Furthermore, the unique solution of the optimal parameter can be obtained. Compared with the LQR control method, the effectiveness of the optimization method of robust constraint following control was verified.

scholarly journals Efficiency Optimization Design of L-LLC Resonant Bidirectional DC-DC Converter

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3123
Author(s):  
Jing Lu ◽  
Xiangqian Tong ◽  
Jianwu Zeng ◽  
Ming Shen ◽  
Jun Yin
Keyword(s):  
Parameter Optimization ◽  
Optimization Design ◽  
High Efficiency ◽  
Design Method ◽  
Optimization Method ◽  
Switching Loss ◽  
Intrinsic Mechanism ◽  
Parasitic Parameters ◽  
New Type ◽  
Parameter Optimization Design

The new type of L-LLC resonant bidirectional DC-DC converter (L-LLC-BDC) has merits of high efficiency, high-power density and wide gain and power ranges, and it is suitable for energy interface between energy storage systems and DC micro grid. However, the resonances are sensitive to the parasitic parameters, which will deteriorate the efficiency. This paper investigates the intrinsic mechanism of parasitic parameters on the L-LLC-BDC operating principle and working characteristics based on the analysis of working modes and resonance tank. By taking the oscillation of parasitic parameters produced in the stage for the freewheeling stage into consideration, a parameter optimization method is proposed to reduce the resonant current oscillation while maintaining the characteristic of the natural soft switching. The experiment results not only validated the proposed parameter optimization design method, but also testified to the improvement of the efficiency through the minimization of the conduction and switching loss.

A new jig-shape optimization method for the high aspect ratio wing

2018 ◽  
Vol 91 (1) ◽  
pp. 124-133
Author(s):  
Zhe Yuan ◽  
Shihui Huo ◽  
Jianting Ren
Keyword(s):  
Aspect Ratio ◽  
Shape Optimization ◽  
High Aspect Ratio ◽  
Optimization Design ◽  
Design Method ◽  
Aircraft Design ◽  
Optimization Method ◽  
Attack Angle ◽  
Structural Deformation ◽  
Content Type

Purpose Computational efficiency is always the major concern in aircraft design. The purpose of this research is to investigate an efficient jig-shape optimization design method. A new jig-shape optimization method is presented in the current study and its application on the high aspect ratio wing is discussed. Design/methodology/approach First, the effects of bending and torsion on aerodynamic distribution were discussed. The effect of bending deformation was equivalent to the change of attack angle through a new equivalent method. The equivalent attack angle showed a linear dependence on the quadratic function of bending. Then, a new jig-shape optimization method taking integrated structural deformation into account was proposed. The method was realized by four substeps: object decomposition, optimization design, inversion and evaluation. Findings After the new jig-shape optimization design, both aerodynamic distribution and structural configuration have satisfactory results. Meanwhile, the method takes both bending and torsion deformation into account. Practical implications The new jig-shape optimization method can be well used for the high aspect ratio wing. Originality/value The new method is an innovation based on the traditional single parameter design method. It is suitable for engineering application.

Shape Optimization Design of Gravity Buttress of Arch Dam Based on Asynchronous Particle Swarm Optimization Method

2014 ◽  
Vol 662 ◽  
pp. 160-163
Author(s):  
Lei Xu
Keyword(s):  
Particle Swarm Optimization ◽  
Optimization Design ◽  
Design Method ◽  
Particle Swarm ◽  
Optimization Method ◽  
Arch Dam ◽  
Swarm Optimization ◽  
Safety Coefficient ◽  
Parametric Description ◽  
Particle Swarm Optimization Method

The optimization design method was rarely used to design the gravity buttress of arch dam in the past. With this in mind, the parametric description of gravity buttress is given, and the auto-calculation of its exerting loads and the safety coefficient of anti-slide stability are realized subsequently. Then, the optimization design model of gravity buttress and the procedures of optimization design are presented using the asynchronous particle swarm optimization method. Finally, ODGB software, which is short for Optimization Design of Gravity Buttress software, is developed and verified.

scholarly journals Small-Signal Modeling and Parameter Optimization Design for Photovoltaic Virtual Synchronous Generator

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 398 ◽  
Author(s):  
Jun Deng ◽  
Nan Xia ◽  
Jungang Yin ◽  
Jiliang Jin ◽  
Shutao Peng ◽  
...  
Keyword(s):  
Optimization Design ◽  
Control Method ◽  
Design Method ◽  
Synchronous Generator ◽  
System Stability ◽  
Operating Point ◽  
Small Signal ◽  
Stochastic Fluctuation ◽  
Photovoltaic Power ◽  
Virtual Synchronous Generator

With the continuous proliferation of renewable energy generation, distributed photovoltaic inverters operating at a maximum power point reduce the inertia of power systems, degrading system frequency stability and potentially causing severe oscillations in systems after being disturbed. The virtual synchronous generator (VSG) control method, which causes photovoltaic inverters to possess inertia and damping, now plays an important role in the field of distributed generation. However, while introducing the advantages of synchronous machines, problems with oscillations are also introduced and the stochastic fluctuation characteristic of photovoltaics results in the stochastic drifting of the operating point. This paper presents an adaptive controller parameter design method for a photovoltaic-VSG (PV-VSG) integrated power system. Firstly, a small-signal model of the PV-VSG is built and a state space model is deduced. Then, the small-signal stability and low frequency oscillation characteristics of the photovoltaic power generation system are analyzed. Finally, considering the limitations of system oscillations and the stochastic drifting of the operating point, a global optimization design method for controller parameters used to improve system stability is proposed. The time domain simulation shows that an optimized PV-VSG could provide sufficient damping in the case of photovoltaic power output changes across a wider range.

Multi-Objective Optimization Design Method for Tandem Compressor Cascade at Design and Off Design Conditions

2010 ◽  
Author(s):  
Yaping Ju ◽  
Chuhua Zhang
Keyword(s):  
Optimization Design ◽  
Design Method ◽  
Pressure Ratio ◽  
Aerodynamic Performance ◽  
Multi Objective Optimization ◽  
Ann Model ◽  
Compressor Cascade ◽  
Control Cost ◽  
Multi Objective ◽  
Operation Conditions

Recently, there has been a renewed interest in the research of tandem compressor cascades due to the high stage pressure ratio and low control cost. Firstly, the computational fluid dynamics (CFD) method is employed to examine the particular aerodynamic performance of the tandem cascade. Then we propose an automatic multi-objective optimization design method of the tandem cascade for the superior aerodynamic performance under the multiple operation conditions. Particular efforts have been devoted to the gap geometry optimization in terms of the front and aft airfoil relative position, camber turning ratio as well as chord ratio. The multi-objective optimization algorithm comprises a refined multi-objective genetic algorithm (MOGA) and a developed artificial neural network (ANN) model which is used to fast approximate the aerodynamic performance of the tandem cascade. The results show that the tandem cascade outperforms the single cascade in terms of producing higher pressure ratio and lower losses while the operation range is rather narrow. The optimized all-better-than (ABT) tandem cascade has its design point performance significantly improved while the operation range slightly widened. We also find that a slight axial proximity and separation of the tandem airfoils are beneficial to widening the positive and negative operation range, respectively. This research is useful to the tandem compressor cascade design in minimizing the stage number of the engine compressors.

Improving the Robustness of Adjoint-Based Airfoil Drag Reduction Design

2013 ◽  
Vol 444-445 ◽  
pp. 259-263
Author(s):  
Yan Hong Fan
Keyword(s):  
Drag Reduction ◽  
Optimization Design ◽  
Line Search ◽  
Optimization Problem ◽  
Design Method ◽  
Optimization Method ◽  
Search Method ◽  
Linear Search

The effect of steps in the line search on the consistence of adjoint-based drag reduction of airfoil is investigated in this paper. Constant step adopted in drag reduction design usually gives different optimization results and choice of constant step often depends on designers experience and optimization problem. Bracket method is applied to automatically give the optimal step in performing drag reduction design of airfoils RAE2822 and S73613 and the consistent optimal results are obtained. The results illustrate that the linear search method can automatically find the optimal step, and overcome the restriction on choice of user-defined constant step which is used in the traditional adjoint-based optimization method. That is, it reduces the dependence of step in the drag reduction design, and improves the robustness of the adjoint-based airfoil drag reduction optimization design method.

An Optimization Design Method of Geometric Parameters of Skid Shoe Referring to Subject Weight of Marine Structures

2014 ◽  
Vol 678 ◽  
pp. 325-332
Author(s):  
Feng Yan Yang ◽  
Xiang Zhen Yan ◽  
Zheng Rong Song ◽  
Ming Wang Yang ◽  
Zi Kun Zhao ◽  
...  
Keyword(s):  
Optimization Design ◽  
Design Method ◽  
Plate Thickness ◽  
Optimization Method ◽  
Geometric Parameters ◽  
Frame Structure ◽  
Complex Method ◽  
Optimized Design ◽  
Original Design ◽  
Marine Structures

The optimization design method of geometric parameters of skid shoe which is used to subject weight of marine structures is proposed. Considering skid shoe as steel frame structure, total weight and the bearing capacity of the skid shoe are selected as optimal objectives, and geometric parameters of the skid shoe are taken as design variables. Taking the strength, stiffness, local stability of the skid shoe as the constraint conditions, multi-objectives constraints optimization model of geometric parameters is established, and solved based on complex method. According to research results, a computer program has been developed using VC language. Then geometric optimum parameters of skid shoe in service of CNOOC are analyzed by the program. The results show that optimized design decreases steel volume, steel plate thickness by 28.7%, 18.4%, respectively, compared with original design. The optimization method has a series of advantages, such as simple model, fast calculating speed, high calculation accuracy.

Intelligent Optimization Design of the Cutting Unit’s Transmission System of a Shearer Based on Robustness

2021 ◽  
pp. 2158009
Author(s):  
Hongbin Gao ◽  
Junjun Chen
Keyword(s):  
Optimization Design ◽  
Design Method ◽  
Harmonic Balance Method ◽  
Optimization Method ◽  
Transmission System ◽  
Gear Transmission ◽  
Manufacturing Cost ◽  
Tooth Width ◽  
Gear Transmission System ◽  
Cutting Unit

To improve the robustness of the shearer cutting part and reduce the manufacturing cost, in this study, the gear transmission system of a shearer’s cutting unit can be divided into three basic components: single-gear-on-one-shaft form, the planetary reduction form, and double-gears-on-one-shaft form. The dynamic differential equations of each structure are established in this study, and the volume functions of the three basic components are obtained. The characteristics of the internal excitation of the gear transmission system are analyzed, and a scheme for solving the motion parameters of each component is formulated based on the harmonic balance method. Based on the parameters, such as tooth width, tooth number, and modulus, as optimized variables, a robust optimization method minimizing the multi-parameter evaluation function, which is weighted linearly by dimensionless vibration and volume of the gear transmission system, is presented. The gear transmission system of a sample shearer’s cutting unit is optimized using the proposed method. The results show that the transmission system’s size decreases by 5.4%, the drum’s maximum torsional acceleration decreases by 17.8%, and the first gear’s maximum torsional acceleration decreases by 9.6%. Thus, we conclude that the optimum design method decreases a shearer’s manufacturing cost and decreases the cutting unit’s failure rate.

Study on Optimization Design of a Hoist Roller

2011 ◽  
Vol 415-417 ◽  
pp. 460-463
Author(s):  
Li Liu ◽  
Hong Xia Liu
Keyword(s):  
Optimization Design ◽  
Design Method ◽  
Plate Thickness ◽  
Optimization Method ◽  
Practical Significance ◽  
Application Software ◽  
Side Plate ◽  
Design Variables ◽  
Programming Software ◽  
Set Up

In the design of wrapping hoist, the roller strength is always a larger problem. In this paper, diameter, wall thickness and side plate thickness of the roller were selected as design variables, and volume of the roller acts as object function. Through analyzing its inner stresses, the mechanical model and mathematical model were set up. Adopting the optimization method of covering complex and VB programming software, an application software of a hoist roller optimization design was got. An example is used to verify correctness and practicability of the software. This optimization design method has practical significance on reducing the weight and material of a hoist roller.

Robust Adaptable Design of Mechanical Products

2013 ◽  
Author(s):  
Jian Zhang ◽  
Yongliang Chen ◽  
Deyi Xue ◽  
Peihua Gu
Keyword(s):  
Optimal Design ◽  
Functional Performance ◽  
Optimal Parameter ◽  
Design Method ◽  
Optimization Method ◽  
Adaptable Design ◽  
Operation Stage ◽  
Mechanical Products ◽  
Tree Product ◽  
Parameter Values

For an adaptable product, both configuration and parameter values associated with the configuration can be adapted in the product operation stage to satisfy different requirements. This research aims at developing a new design approach to identify the adaptable product whose functional performance is the least sensitive to parameter variations caused by uncertainties. First different configuration candidates in design and different product configurations in operation stage to satisfy design requirements are modeled by a novel hybrid AND-OR tree. Product/operating parameters associated with configurations are also modeled. A two-level optimization method is developed for identifying the optimal design configuration and the parameter values: design configuration optimization for identifying the optimal design configuration and parameter optimization for identifying the optimal parameter values associated with this design configuration. Case study of an adaptable vibratory feeder is developed to demonstrate the effectiveness of the newly developed robust adaptable design method.

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