Efficient Gradient-Based Tolerance Optimization Using Monte Carlo Simulation

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
R. Alan Bowman
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Manufacturing Cost ◽  
Optimization Approach ◽  
Functional Requirements ◽  
Mechanical Assembly ◽  
New Approach ◽  
Tolerance Optimization ◽  
Gradient Based ◽  
Derivatives Of

A gradient-based optimization approach is employed to select design tolerances for the component dimensions of a mechanical assembly to minimize manufacturing cost while achieving a desired probability of meeting functional requirements, known as the yield. Key to the feasibility of such an approach is to be able to use Monte Carlo simulation to make estimates of the derivatives of the yield with respect to the design tolerances quickly and accurately. A new approach for making these estimates is presented and is shown to be far faster and more accurate than previous approaches. Gradient-based optimization using the new approach for estimating the derivatives is applied to example problems from the literature. The solutions are superior to all previously published solutions and are obtained with very reasonable computer run times. Additional advantages of a gradient-based approach are described.

Optimization of Design Tolerances Through Response Surface Approximations

2002 ◽  
Vol 124 (3) ◽  
pp. 762-767 ◽  
Author(s):  
J. P. Jordaan ◽  
C. P. Ungerer
Keyword(s):  
Monte Carlo ◽  
Response Surface ◽  
Design Space ◽  
Analytical Relationship ◽  
Manufacturing Cost ◽  
Functional Requirements ◽  
Mechanical Assembly ◽  
Response Surface Approximations ◽  
Yield Values ◽  
Optimal Set

A methodology whereby the optimal set of design tolerances is assigned to the dimensions of a general mechanical assembly, is developed and tested. The manufacturing cost is minimized, while the design is constrained to a specified probability of meeting functional requirements, called the yield of the design. An analytical relationship for the assembly yield surface is generally unknown, and use is made of response surface approximations in the optimization algorithm. Yield values are determined at design space points through Monte Carlo simulations, seen as the response surface experiments. The methodology is benchmarked on example problems from the literature, and the optimum compares superior to published results.

New approach to Monte Carlo simulation of photon transport in the frequency domain

1995 ◽  
Author(s):  
Ilya V. Yaroslavsky ◽  
Anna N. Yaroslavsky ◽  
Hans-Joachim Schwarzmaier ◽  
Garif G. Akchurin ◽  
Valery V. Tuchin
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Frequency Domain ◽  
New Approach ◽  
Photon Transport

scholarly journals Shielding Analysis of Metal Hydride-based Materials for Both Neutron and Gamma Rays Using Monte Carlo Simulation

2021 ◽  
Vol 59 (12) ◽  
pp. 921-925
Author(s):  
Jeongkwon Kwak ◽  
Boravy Muth ◽  
Hyeon-Woo Yang ◽  
Chang Je Park ◽  
Woo Seung Kang ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Gamma Rays ◽  
Multilayer Structure ◽  
Gamma Ray ◽  
Accurate Method ◽  
Multilayered Structure ◽  
Manufacturing Cost ◽  
Human Poisoning ◽  
Set Up

Radiation causes damage to the human body, the environment, and electronic equipment. Shielding against neutron and gamma rays is particularly difficult because of their strong ability to penetrate materials. Conventional gamma ray shields are typically made of materials containing Pb. However, they pose problems in that Pb is a heavy metal, and human poisoning and/or pollution can result from the manufacturing, use, and disposal of these materials. In addition, neutron rays are shielded by materials rich in H2 or concrete. In the case of the latter, the manufacturing cost is high. Thus, it is necessary to develop a new multilayer structure that can shield against both neutron and gamma rays. We set up a simulation model of a multilayered structure consisting of metal hydrides and heavy metals, and then evaluated the simulations using Monte Carlo N-Particle Transport Code. Monte Carlo simulation is an accurate method for simulating the interaction between radiation and materials, and can be applied to the transport of radiation particles to predict values such as flux, energy spectrum, and energy deposition. The results of the study indicated the multilayer structure of ZrH2, U, and W could shield both neutron and gamma rays, thus showing potential as a new shielding material to replace Pb and concrete.

Tolerance modelling and robust design for concurrent engineering

2007 ◽  
Vol 221 (4) ◽  
pp. 455-465 ◽  
Author(s):  
J Hu ◽  
Y Peng
Keyword(s):  
Robust Design ◽  
Concurrent Engineering ◽  
Manufacturing Cost ◽  
Functional Requirements ◽  
Manufacturing Costs ◽  
Tolerance Optimization ◽  
Geometric Tolerances ◽  
Genetic Arithmetic ◽  
Tolerance Modelling ◽  
Tolerance Model

This article presents a tolerance modelling and robust design approach to support concurrent engineering. This method allows the designer to synthetically specify dimensional and geometric tolerance, considering assembly functional requirements (AFRs) and manufacturing costs. First, features of ISO/TC 213 are used as the basis for the construction of tolerance network and tolerance model for assembly. Second, the manufacturing cost-tolerance model for cylindrical and planar features is established. This model addresses not only dimensional tolerances but also geometric tolerances and nominal parameters. Finally, the robust tolerance optimization model is established, and genetic arithmetic is used to obtain robust tolerance values. The proposed approach is consistent with the philosophy of concurrent engineering, in which AFRs are satisfied and manufacturing cost is reduced. A design instance is introduced to show the validity of this method.

An Optimization Approach Toward a Robust Design of Six Degrees of Freedom Haptic Devices

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Aftab Ahmad ◽  
Kjell Andersson ◽  
Ulf Sellgren
Keyword(s):  
Design Optimization ◽  
Robust Design ◽  
Degrees Of Freedom ◽  
Design Parameters ◽  
Manufacturing Cost ◽  
Optimization Approach ◽  
Performance Indices ◽  
New Approach ◽  
Haptic Devices ◽  
Six Degrees Of Freedom

This work presents an optimization approach for the robust design of six degrees of freedom (DOF) haptic devices. Our objective is to find the optimal values for a set of design parameters that maximize the kinematic, dynamic, and kinetostatic performances of a 6-DOF haptic device while minimizing its sensitivity to variations in manufacturing tolerances. Because performance indices differ in magnitude, the formulation of an objective function for multicriteria performance requirements is complex. A new approach based on Monte Carlo simulation (MCS) was used to find the extreme values (minimum and maximum) of the performance indices to enable normalization of these indices. The optimization approach presented here is formulated as a methodology in which a hybrid design-optimization approach, combining genetic algorithm (GA) and MCS, is first used. This new approach can find the numerical values of the design parameters that are both optimal and robust (i.e., less sensitive to variation and thus to uncertainties in the design parameters). In the following step, with design optimization, a set of optimum tolerances is determined that minimizes manufacturing cost and also satisfies the allowed variations in the performance indices. The presented approach can thus enable the designer to evaluate trade-offs between allowed performance variations and tolerances cost.

Reliability Analysis of a Robot Manipulator Operation Employing Single Monte-Carlo Simulation

2006 ◽  
Vol 321-323 ◽  
pp. 1568-1571 ◽  
Author(s):  
Dong Hwan Choi ◽  
Hong Hee Yoo
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Reliability Analysis ◽  
Robot Manipulator ◽  
Computing Time ◽  
Manufacturing Cost ◽  
Robot System ◽  
Performance Requirement ◽  
Manufacturing Tolerance ◽  
Design Engineers

The operation error of a robot that occurs inevitably due to the manufacturing tolerance needs to be controlled within a certain range to achieve proper performance of the robot system. The reduction of manufacturing tolerance, however, increases the manufacturing cost in return. Therefore, design engineers try to solve the problem of maximizing the tolerance to reduce the manufacturing cost while minimizing the operation error to satisfy the performance requirement. In the present study, a revolute joint model considering uncertainties due to joint clearance is employed to perform a reliability analysis of the robot manipulator operation. The reliability analysis procedure employs single Monte-Carlo simulation and a statistical relation between the tolerance and the operation error. Significant reduction of computing time can be achieved with the proposed method. The present method is especially effective if sensitivity information is hard to be obtained for the analysis.

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