scholarly journals USING ANSYS WB FOR OPTIMIZING PARAMETERS OF A TOOL FOR ROTARY FRICTION BORING

Author(s):  
B.S. Donenbaev ◽  
K.T. Sherov ◽  
M.R. Sikhimbayev ◽  
B.N. Absadykov ◽  
N.Zh. Karsakova

The authors developed a special design of a rotary friction tool with a self-rotating cup cutter for rotary friction boring of large holes. This paper presents the results of parametric optimization of stressed components of the rotary friction tool by virtual experiments in ANSYS WB. The authors predicted the cutting force components at the worst position of the cup cutter, which was 20 degrees as contact forces in the process of boring a large diameter hole, and built a design model. Using the Johnson-Cook model as the failure criterion for the elements of the mesh, projections of the cutting forces resulting from the hole processing were obtained. The relation between input and output parameters (stresses) is established, optimization criteria are specified, and optimal parameters of the tool stresses components are chosen. It was also found that the averaged values of the force at the initial moment (cutting into the workpiece) change linearly, then becoming practically constant. The idea of parametric optimization consisted in carrying out several virtual experiments, in which the possible range of variation of the basic dimensions was indicated and the optimization criteria were set, the optimal parameters of the tool design were selected from the presented candidates. The optimization method bypasses the design cycle, which is costly and time-consuming due to prototype testing and subsequent refinement.

2020 ◽  
Vol 21 (4) ◽  
pp. 242-248
Author(s):  
Do Quang Thong

Modern air targets are characterized by low visibility, high maneuverability and high survivability. In addition, for some specific targets, for instance ballistic missiles, in order to defeat them the missile need tobe guided and carried out direct hit, i.e. "hit to kill". Therefore, in this paper, we present a high-precision missile homing system (MHS) using the proportional guidance method for firing at the highly maneuverable targets. Specifically, we propose a parametric optimization method for choosing a set of optimal parameters of the missile homing system for each dynamic parameter set of the missile. In addition, the paper gives the recommendations of choosing the initial conditions for the synthesis of missile homing system. In our experience, we should choose the small initial condition for synthesizing the missile homing system. Finally, the article also investigates the influence of systematic error in determining the speed, normal acceleration of missiles and the angular velocity of the line of sight of the missile and target on the accuracy of the missile homing system. We implement the proposed missile homing system and the parametric optimization method in Matlab. The experimental results illustrate that, using proposed system and the parametric optimization method, the missile can defeat the modern air targets with low visibility, high maneuverability and high survivability. 


2019 ◽  
Vol 13 ◽  
Author(s):  
Yan Zhang ◽  
Ren Sheng

Background: In order to improve the efficiency of fault treatment of mining motor, the method of model construction is used to construct the type of kernel function based on the principle of vector machine classification and the optimization method of parameters. Methodology: One-to-many algorithm is used to establish two kinds of support vector machine models for fault diagnosis of motor rotor of crusher. One of them is to obtain the optimal parameters C and g based on the input samples of the instantaneous power fault characteristic data of some motor rotors which have not been processed by rough sets. Patents on machine learning have also shows their practical usefulness in the selction of the feature for fault detection. Results: The results show that the instantaneous power fault feature extracted from the rotor of the crusher motor is obtained by the cross validation method of grid search k-weights (where k is 3) and the final data of the applied Gauss radial basis penalty parameter C and the nuclear parameter g are obtained. Conclusion: The model established by the optimal parameters is used to classify and diagnose the sample of instantaneous power fault characteristic measurement of motor rotor. Therefore, the classification accuracy of the sample data processed by rough set is higher.


2012 ◽  
Vol 192 ◽  
pp. 180-184 ◽  
Author(s):  
Ai Xia He ◽  
Rong Chang Li

Mechanical expanding process for large diameter line pipe, a detailed analysis of factors affecting the quality of the final products of the mechanical expansion and proposed optimization using orthogonal array optimization method, as an indicator of dimensional accuracy and shape accuracy of the products, combination of a variety of specifications of mechanical expanding products, the main process parameters to be optimized. Analysis and discussion of results, revealing the degree of influence of various factors on the quality of the final product, and gives the optimum combination of the results. Experiments show that the combination of optimized process parameters, and more help to improve the accuracy of the size and shape of products.


2009 ◽  
Vol 419-420 ◽  
pp. 645-648 ◽  
Author(s):  
Qun Ming Li ◽  
Dan Gao ◽  
Hua Deng

Different from dexterous robotic hands, the gripper of heavy forging manipulator is an underconstrained mechanism whose tongs are free in a small wiggling range. However, for both a dexterous robotic hand and a heavy gripper, the force closure condition: the force and the torque equilibrium, must be satisfied without exception to maintain the grasping/gripping stability. This paper presents a gripping model for the heavy forging gripper with equivalent friction points, which is similar to a grasp model of multifingered robot hands including four contact points. A gripping force optimization method is proposed for the calculation of contact forces between gripper tongs and forged object. The comparison between the calculation results and the experimental results demonstrates the effectiveness of the proposed calculation method.


2021 ◽  
Vol 22 (7) ◽  
pp. 365-373
Author(s):  
Quang Thong Do

The proportional guidance method-based missile homing systems (MHS) have been widely used the real-world environments. In these systems, in order to destroy the targets at different altitudes, a normal acceleration stabilization system (NASS) is often utilized. Therefore, the MHS are complex and the synthesis of these systems are a complex task. However, it is necessary to synthesize NASS during the synthesis of the MHS. To simplify the synthesis process, a linear model of the NASS is used. In addition, we make use of the available commands in Control System Toolbox in MATLAB. Because the Toolbox has the commands to describe the transfer function, determine the stability gain margin, and the values of the transient respond of the linear automatic systems. Thus, this article presents two methods for synthesizing the missile homing systems, including (i) a method for synthesizing the MHS while ensuring the permissible stability gain margin of the NASS, and (ii) a method for synthesizing the MHS while ensuring the permissible stability margin of the NASS by overshoot. These techniques are very easy to implement using MATLAB commands. The synthesis of the proposed MHS is carried out by the parametric optimization method. To validate the performance of the proposed techniques, we compare them withthe MHS synthesized by ensuring the stability margin of the NASS bythe oscillation index. The results show that, two our proposed methods and the existing method provide the same results in terms of high-precision. Nevertheless, the proposed methods are simple and faster than the conventional method. The article also investigates the effect of gravity, longitudinal acceleration of the rocket, andblinding of the homing head on the accuracy of the synthesized MHS. The results illustrate that they have a little effect on its accuracy.


Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 943
Author(s):  
Chong Zhang ◽  
Zhenhua Di ◽  
Qingyun Duan ◽  
Zhenghui Xie ◽  
Wei Gong

Land surface evapotranspiration (ET) is important in land-atmosphere interactions of water and energy cycles. However, regional ET simulation has a great uncertainty. In this study, a highly-efficient parameter optimization framework was applied to improve ET simulations of the Community Land Model version 4.0 (CLM4) in China. The CLM4 is a model at land scale, and therefore, the monthly ET observation was used to evaluate the simulation results. The optimization framework consisted of a parameter sensitivity analysis (also called parameter screening) by the multivariate adaptive regression spline (MARS) method and sensitivity parameter optimization by the adaptive surrogate modeling-based optimization (ASMO) method. The results show that seven sensitive parameters were screened from 38 adjustable parameters in CLM4 using the MARS sensitivity analysis method. Then, using only 133 model runs, the optimal values of the seven parameters were found by the ASMO method, demonstrating the high efficiency of the method. For the optimal parameters, the ET simulations of CLM4 were improved by 7.27%. The most significant improvement occurred in the Tibetan Plateau region. Additional ET simulations from the validation years were also improved by 5.34%, demonstrating the robustness of the optimal parameters. Overall, the ASMO method was found to be efficient for conducting parameter optimization for CLM4, and the optimal parameters effectively improved ET simulation of CLM4 in China.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Zhendong Hu ◽  
Ju Qiu ◽  
Fa Zhang

An optimization technique called shape-linked optimization, which is different from the traditional optimization method, is introduced in this paper. The research introduces an updated wing optimization design in an effort to adapt to continuous structure changes and shapes while optimizing for a lighter weight of the structure. The changing tendencies of the thickness of wing skins and the cross-section areas of the wing beams are fitted to continuous polynomial functions, whose coefficients are designed as variables, which is a different engineering approach from the size variants of the thickness and the area in the traditional optimization. The structural strength, stiffness, and stability are constraints. Firstly, this research unearths the significance of utilizing a modernized optimization process which alters the production of the traditional 12 or over 12 segment wing design and applies new approaches and methods with less variables that contribute to expedited design cycles, decreased engineering and manufacturing expenditures, and a lighter weight aircraft with lower operating costs than the traditional design for the operators. And then, this paper exemplifies and illustrates the validity of the above claims in a detailed and systematic approach by comparing traditional and modernized optimization applications with a two-beam wing. Finally, this paper also proves that the new optimized structure parameters are easier than the size optimization to process and manufacture.


Author(s):  
Dennis W. Hong ◽  
Raymond J. Cipra

One of the inherent problems of multi-limbed mobile robotic systems is the problem of multi-contact force distribution; the contact forces and moments at the feet required to support it and those required by its tasks are indeterminate. A new strategy for choosing an optimal solution for the contact force distribution of multi-limbed robots with three feet in contact with the environment in three-dimensional space is presented. The optimal solution is found using a two-step approach: first finding the description of the entire solution space for the contact force distribution for a statically stable stance under friction constraints, and then choosing an optimal solution in this solution space which maximizes the objectives given by the chosen optimization criteria. An incremental strategy of opening up the friction cones is developed to produce the optimal solution which is defined as the one whose foot contact force vector is closest to the surface normal vector for robustness against slipping. The procedure is aided by using the “force space graph” which indicates where this solution is positioned in the solution space to give insight into the quality of the chosen solution and to provide robustness against disturbances. The “margin against slip with contact point priority” approach is also presented which finds an optimal solution with different priorities given to each foot contact point for the case when one foot is more critical than the other. Examples are presented to illustrate certain aspects of the method and ideas for other optimization criteria are discussed.


Author(s):  
Sergio Andrés Pizarro Pérez ◽  
John E. Candelo-Becerra ◽  
Fredy E. Hoyos Velasco

The inertia issues in a microgrid can be improved by modifying the inverter control strategies to represent a virtual inertia simulation. This method employs the droop control strategy commonly used to share the power of a load among different power sources in the microgrid. This paper utilizes a modified droop control that represents this virtual inertia and applies an optimization algorithm to determine the optimal parameters and improve transient response. The results show better control when different variations are presented in the loads, leading the microgrid to have a better control of the operation. The optimization method applied in this research allows improvement to the transient response, thus avoiding unnecessary blackouts in the microgrid.


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