Robust Design Concept Research Articles

A semi-analytic approach to robust design in the conceptual design phase

One of the most important contributions to quality engineering over the last decades is the concept of robust design and its accomplishment through the use of various experimental methods. However, the prerequisite for successful parameter design in terms of a robust solution principle is seldom discussed. Methods that explicitly aid robust design in the conceptual design phase exist but are few. This article forwards the suggestion to use the principles behind the error transmission formula as a semi-analytic method for evaluation of robustness of concept solutions, prior to entering Taguchi's parameter design stage.

Full envelope flight control system design using quantitative feedback theory

A controlled plant's characteristics can vary widely throughout its operational envelope. This is a major problem in nominal plant-based control system design. Hence, gain scheduling is often used for full envelope design. In this paper, it is proposed to address the plant's variability using robust control design concepts, minimizing the need for gain scheduling. In particular, the frequency-domain-based quantitative feedback theory multiple input multiple output robust controls design method is employed for the synthesis of a full envelope flight control system for an F-16 aircraft derivative. Qualitative feedback theory addresses structured uncertainty that is caused by full envelope operation. Thus, qualitative feedback theory robust control is particularly suited for full envelope controller design. Compensators and prefilters for the aircraft's pitch and lateral/directional channels are designed to meet level 1 flying qualities specifications, and these designs are validated using simulations.

Robust design using an efficient sampling technique

The concept of robust design involves identification of design settings that make the product performance less sensitive to the effects of seasonal and environmental variations. Batch processes are more flexible compared to continuous processes and are frequently used in these situations. Stochastic optimization methods provide a general approach to robust/ parameter design as compared to conventional techniques. However, the computational burden of these approaches can be extreme and depends on the sample size used for characterizing the parametric variations and uncertainties. In this paper, we present a novel sampling technique. The example of robust batch distillation column design illustrates that the new sampling technique offers significant computational savings and better accuracy.

Robust design and optimization of material handling in an FMS

Although a significant amount of simulation research has been carried out for design and analysis of flexible manufacturing systems (FMS), it does not provide optimal solutions. In this research, we employ two optimum-seeking methods to design and optimize a manufacturing system. The first method is a Taguchi approach, which uses robust design concept to reduce the output variation. The second method is the response surface methodology (RSM), which combines mathematical and statistical techniques to study the geography of the response surface. The results show that throughput of a selected FMS system can be maximized when both methods are employed.

Design of process parameters using robust design techniques and multiple criteria optimization

This paper presents a methodology for the design of products/processes that makes use of the concepts of robust design and the techniques of multiple criteria optimization for simultaneously optimizing many quality characteristics. First, a systematic approach to the selection of an efficient matrix experiment for a design problem is presented. Appropriate performance measures are obtained so that their joint optimization results in the minimum variation of product characteristics. The use of transformations is highlighted as a useful technique to statistically validate the design process. A discrete multiple criteria optimization algorithm that incorporates the methods of dominated approximations and reference points is developed to obtain nondominated solutions for the design problem. The methodology is illustrated using a case study gleaned from the literature.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Designing products that are robust to the environment

Professor Genichi Taguchi has emphasized the use of designed experiments in several novel and important applications. In this paper, we focus on the use of statistical experimental designs in designing products to be robust to environmental conditions. The engineering concept of robust product design is very important since it is frequently impossible or prohibitively expensive to control or eliminate sources of variation due to environmental conditions. Robust product design enables the experimenter to discover how to modify the design of the product to minimize the effect due to variation from environmental sources. In experiments of this kind, Professor Taguchi's total experimental arrangement consists of a cross-product of two experimental designs, an inner array containing the design factors and an outer array containing the environmental factors. Except in situations where both of these arrays are small, this arrangement may involve a prohibitively large amount of experimental work. One of the objec...

Split-plot designs for robust product experimentation

Genichi Taguchi has emphasized the use of designed experiments in several novel and important applications. In this paper we focus on the use of statistical experimental designs in designingproducts to be robust to environmental conditions. The engineering concept of robust product design is very important because it is frequently impossible or prohibitively expensive to control or eliminate variation resulting from environmental conditions. Robust product design enablesthe experimenter to discover how to modify the design of the product to minimize the effect dueto variation from environmental sources. In experiments of this kind, Taguchi's total experimental arrangement consists of a cross-product of two experimental designs:an inner array containing the design factors and an outer array containing the environmental factors. Except in situations where both these arrays are small, this arrangement may involve a prohibitively large amount of experimental work. One of the objectives of this paper is to show how this amount of work can be reduced. In this paper we investigate the applicability of split-plot designs for thisparticular experimental situation. Consideration of the efficiency of split-plot designs and anexamination of several variants of split-plot designs indicates that experiments conductedin a split-plot mode can be of tremendous value in robust product design since they not only enable the contrasts of interest to be estimated efficiently but also the experiments can be considerably easier to conduct than the designs proposed by Taguchi.

Robust design

Robust design is a powerful technique for developing processes that produce desirable outcomes, even in the presence of factors that cannot be controlled or cannot be controlled economically. In the past 12 years several leading high-technology manufacturing companies in the United States have applied robust design methods with considerable success. This article discusses the basic concepts of robust design and speculates on how these ideas might be applied to health care quality management.

Design Optimization Case Studies

Designing high quality products at low cost is an economic and technological challenge to the engineer. A systematic and efficient way to meet this challenge is a new method of design optimization for performance, quality, and cost. The method, called “robust design,” has been found effective in many areas of engineering design. In this paper, the basic concepts of robust design will be discussed and two applications will be described in detail. The first application illustrates how, with a very small number of experiments, highly valuable information can be obtained about a large number of variables for improving the life of router bits used for cutting printed wiring boards from panels. The second application shows the optimization of a differential operational amplifier circuit to minimize the dc offset voltage by moving the center point of the design, which does not add to the cost of making the circuit.