Dynamics Design of a Planar Controllable Five Bar Mechanism Based on Genetic Algorithm

Author(s):  
Ke Zhang

A hybrid five bar mechanism is a typical planar parallel robot. It is a configuration that combines the motions of two characteristically different motors by means of a five bar mechanism to produce programmable output. Hybrid five bar mechanism is the most representative one of hybrid mechanism. In this paper, considering the bond graph can provide a compact and versatile representation for kinematics and dynamics of hybrid mechanism, the dynamics analysis for a hybrid five-bar mechanism based on power bond graph theory is introduced. Then an optimization design of hybrid mechanism is performed with reference to dynamic objective function. By the use of the properties of global search of genetic algorithm (GA), an improved GA algorithm is proposed based on real-code. Optimum dimensions are obtained assuming there are no dimensional tolerances or clearances. Finally, a numerical example is carried out, and the simulation result shows that the optimization method is feasible and satisfactory in the design of hybrid mechanism.

2012 ◽  
Vol 482-484 ◽  
pp. 452-456 ◽  
Author(s):  
Gui Hua Fang ◽  
Chao Chen ◽  
Jin Feng Liu

The structure and the operating principle of automobile hydraulic power-assistant steering system (HPS) are studied. The state-pace equation of the system is established by applying power bond graph method. The simulation of HPS is carried on in Simulink which is a software package of Matlab, and the dynamical properties of HPS are analyzed under different conditions. The simulation consequences provide theoretical basis for performance analysis and optimization design of HPS.


2014 ◽  
Vol 951 ◽  
pp. 274-277 ◽  
Author(s):  
Xu Sheng Gan ◽  
Can Yang ◽  
Hai Long Gao

To improve the optimization design of Radial Basis Function (RBF) neural network, a RBF neural network based on a hybrid Genetic Algorithm (GA) is proposed. First the hierarchical structure and adaptive crossover probability is introduced into the traditional GA algorithm for the improvement, and then the hybrid GA algorithm is used to optimize the structure and parameters of the network. The simulation indicates that the proposed model has a good modeling performance.


2014 ◽  
Vol 889-890 ◽  
pp. 107-112
Author(s):  
Ji Ming Tian ◽  
Xin Tan

The design of the gearbox must ensure the simplest structure and the lightest weight under the premise of meeting the reliability and life expectancy. According to the requirement of wind turbine, an improved method combined dynamic penalty function with pseudo-parallel genetic algorithm is used to optimize gearbox. It takes the minimum volumes as object functions. It is showed that the ability to search the global optimal solution of improved genetic algorithm and less number of iterations. The global optimal solution is worked out quickly. The size parameters are optimized, as much as the driving stability and efficiency. To verify the feasibility of improved genetic algorithm, ring gear of the gearbox is analyzed. Static strength analysis shows that the optimization method is reasonable and effective.


2011 ◽  
Vol 250-253 ◽  
pp. 2672-2677 ◽  
Author(s):  
Xian Song Xie ◽  
Dong Jin Yan ◽  
Yue Zhai Zheng

Genetic algorithm is a non-numerical optimization method which based on natural selection and population genetics.Using genetic algorithm to optimize the mix proportion design of high performance concrete, it takes into account the economic profitability on the foundation of satisfying the requirements of durability, strength, workability and dimensional stability of concrete, it establishes a mathematic model applying the performance of material as constraint condition, and the economic cost as optimization target.Using binary coding to represent the chromosome bit serial of individual, through selection, crossover, mutation and other genetic operator to conduct global probability search, taking the principle of “survival of the fittest”, finally achieve the best population and individual. Compare the results of optimization with the mix proportion in practice engineering case, we can reach the conclusion that Genetic Algorithm could reduce the cost, save energy, provides better use value on engineering practice.


2012 ◽  
Vol 178-181 ◽  
pp. 2871-2876
Author(s):  
Chao Wang ◽  
Feng Feng ◽  
Xin Chang ◽  
Chun Yu Guo ◽  
Yang Hao Liu

Hydrofoil is the important part of ship design and diverse motion equipment. The optimization design of hydrofoil section on lift-to-drag radio with genetic algorithm (GA) and simulated annealing algorithm are demonstrated, and the method on the hydrofoil section design of the propeller design will be done. Objective function and fitness of every individual are provided by flow solver of panel method. The optimization method on design of hydrofoil section on lift-to-drag is successfully used. The optimization results show the combination of optimization algorithm is feasible at the optimal design of hydrofoil sections. What’s more, a comparison between two different optimization algorithms is made, a conclusion that the simulated annealing algorithm is better then the genetic algorithm is obtained.


Author(s):  
Hui Yu ◽  
Jinsong Wang ◽  
Guanghong Duan ◽  
Lining Sun

In this paper an optimization method based on the Mechanics of Parallel Robots and orientated on workspace is conducted in the construction of 6-HTRT parallel robot. By analyzing the characteristics of specific workspace and setting up objective functions, optimizations are implemented on the design of parallel robot. As a result of the optimization design, the parallel robot not only figures the minimum overall size of robot structural, but also has workspace unrestricted by the limit range of Hooke joint’s conical angles. The restriction factors on workspace of 6-HTRT parallel robot are reduced thus the algorithm for motion control of the robot is simplified and the performance of the parallel mechanism is improved.


2019 ◽  
Vol 36 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Jingjing Huang ◽  
Longxi Zheng ◽  
Chris K Mechefske ◽  
Bingbing Han

Abstract Based on rotor dynamics theory, a two-disk flexible rotor system representing an aero-engine with freely supported structure was established with commercial software ANSYS. The physical model of the two-disk rotor system was then integrated to the multidisciplinary design optimization software ISIGHT and the maximum vibration amplitudes experienced by the two disks when crossing the first critical speed were optimized using a multi-island genetic algorithm (MIGA). The optimization objective was to minimize the vibration amplitudes of the two disks when crossing the first critical speed. The position of disk 1 was selected as the optimization variable. The optimum position of disk 1 was obtained at the specified constraint that the variation of the first critical speed could not exceed the range of ±10 %. In order to validate the performance of the optimization design, the proof-of-transient experiments were conducted based on a high-speed flexible two-disk rotor system. Experimental results indicated that the maximum vibration amplitude of disk 1 when crossing the first critical speed declined by 60.9 % and the maximum vibration amplitude of disk 2 fell by 63.48 % after optimization. The optimization method found the optimum rotor positions of the flexible rotor system which resulted in minimum vibration amplitudes.


2013 ◽  
Vol 357-360 ◽  
pp. 2410-2413
Author(s):  
Wei Xu ◽  
Jian Sheng Feng ◽  
Fei Fei Feng

The primary object of this fundamental research is to reveal the application of genetic algorithm improved on the optimization design of cantilever supporting structure. In order to meet the strength of pile body and pile top displacement as well as design variables subjected to constraint, an algorithm is carried on to seek the optimum solution and relevant examples by means of comprehensively considering the effects on center-to-center spacing between piles,pile diameter and quantity of distributed steel, which is taken the lowest engineering cost as objective function. Through the comparison of the optimized scheme and original design, this fruitful work provides explanation to the effectiveness of genetic algorithm in optimization design. These findings of the research lead to the conclusion that the shortcomings of traditional design method is easy to fall into local optimal solution. The new optimization method can overcome this drawback.


2010 ◽  
Vol 163-167 ◽  
pp. 2304-2308
Author(s):  
Feng Guo Jiang ◽  
Zhen Qing Wang

Genetic arithmetic operators in genetic algorithm be improved , and a hybrid genetic algorithm of a gradient algorithm combining with the genetic algorithm be given against to the defects such as premature,slow on convergence rate,weak in the ability of local search ,all these appeared on the progress of genetic algorithm's iteration. Analysis result indicate that not only strong on the local search capacity of gradient algorithm be exhibited but also strong on the general search capacity of genetic algorithm be combined based on the hybrid genetic algorithm ,which make phenomenon of premature avoid, and the rate of convergence be improved greatly. Concrete calculated example indicated that the hybrid genetic algorithm is an effective structural optimization method.


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