Paul Regtien

Modelling and calibration of the laser beam-scanning triangulation measurement system

We present an approach of modelling and calibration of an active laser beam-scanning triangulation measurement system. The system works with the pattern of two-dimensional beam-scanning illumination and one-dimensional slit-scanning detection with a photo-multiplier tube instead of a CCD camera. By modelling the system-fixed coordinate, we describe the formulation of 3D computation and propose a calibration method in terms of LSE using a planar fitting algorithm. As a sensor-dependent solution, the estimation is refined in the domain of sensing variables. Result of calibration of the real system and a brief analysis of systematic errors are given.

Systematic and computer-assisted design of measurement systems

In this paper, a new approach is presented for the user guided automatised design of measurement systems. Two concepts are presented: an adapted concept for describing a measurement system and a new concept for the design of a measurement system. For the design concept, a heterarchical implementation is proposed. The applicability of our approach is illustrated with an example from practice.

Multi-sensor recognition of electronic components

Abstract. The Dempster-Shafer theory and the convex Bayesian theory have recently been proposed as alternatives to the (strict) Bayesian theory in the field of reasoning with uncertainty. These relatively new formalisms claim that missing information in the probabilistic model of a process not necessarily disables uncertainty reasoning. However, this paper shows that this does not apply to processes where the reasoning is part of a decision-making process, such as object recognition. In these cases, a complete probabilistic model is required and can be obtained by estimating missing probabilistic information. An examplary approach towards the estimation of uncertain probabilistic information is described in this paper for a multi-sensor system for recognition of electronic components on printed circuit boards.

Volumetric segmentation of range images for printed circuit board inspection

Conventional computer vision approaches towards object recognition and pose estimation employ 2D grey-value or color imaging. As a consequence these images contain information about projections of a 3D scene only. The subsequent image processing will then be difficult, because the object coordinates are represented with just image coordinates. Only complicated low-level vision modules like depth from stereo or depth from shading can recover some of the surface geometry of the scene. Recent advances in fast range imaging have however paved the way towards 3D computer vision, since range data of the scene can now be obtained with sufficient accuracy and speed for object recognition and pose estimation purposes. This article proposes the coded-light range-imaging method together with superquadric segmentation to approach this task. Superquadric segments are volumetric primitives that describe global object properties with 5 parameters, which provide the main features for object recognition. Besides, the principle axes of a superquadric segment determine the phase of an object in the scene. The volumetric segmentation of a range image can be used to detect missing, false or badly placed components on assembled printed circuit boards. Furthermore, this approach will be useful to recognize and extract valuable or toxic electronic components on printed circuit boards scrap that currently burden the environment during electronic waste processing. Results on synthetic range images with errors constructed according to a verified noise model illustrate the capabilities of this approach.

Announcing the 2009 Measurement Science and Technology Outstanding Paper Awards

has awarded a Best Paperprize. The Editorial Board of this journal believes that such a prize is anopportunity to thank authors for submitting their work, and serves as an integralpart of the on-going quality review of the journal.The current breadth of topical areas that are covered by MST has made itadvisable to expand the recognition of excellent publications. Hence, since 2005the Editorial Board have presented ‘Outstanding Paper Awards’ in four subjectcategories: Fluid Mechanics; Measurement Science; Precision Measurements;and Sensors and Sensing Systems. This year also saw the introduction of a newcategory—Optical and Laser-based Techniques.

Thermal modeling of a MEMS for determination of fluid and flow characteristics

The paper presents an one-dimensional model for the heat transfer in a limited but significant region of an actuator-sensor structure for the determination of fluid and flow characteristics. As an essential step for the designing process of this structure, the usefulness of the model in the framework of the structures functionality is underlined. In the first part of the work, the main heat transfer mechanisms are detailed by qualitative and quantitative evaluations. The one-dimensional model is derived from the heat balance of the region we are interested in. In the second part of the work, we compare the data obtained by simulating this model with the experimental data we have. Also, some full three-dimensional simulations of the fluid flow and heat transfer we made using a commercial software package. Part of these numerical results are compared with the corresponding experimental data. The modeling errors are discussed for the both sets of comparisons. Finally, we comment the merits of the one-dimensional model versus the three-dimensional approach. The achieved results obtained herein might be directly used for various thermal based actuators and sensors for flow control and measurement both in micro and macro world.

Investigations into the flow characteristics of hexagonal ducts etched in silicon

This paper focuses on two main subjects encountered in the design process fo the ducts working in the micro yard. They are: the achievement of the Poiseuille number P0 and the achievement of an analytical formula for the velocity field in the hydrodynamically developed flow. These subjects are dictated by the new technologies that support building hexagonal ducts etched in <100

Battery Management Systems: Accurate State-of-Charge Indication for Battery-Powered Applications

GTRsilicon, an usual component of the structures operating in the fluid environment. Concerning the first subject, we develop a procedure for obtaining the Poiseuille number P0 versus that aspect ratio of the hexagonal cross section. The validity of this procedure is proven using different shapes of cross sections. We underline the merit of this procedure, namely the rather straightforward use of a commercial software package. Another subject detailed herein is the building of an approximative analytical formula for the velocity field inside hexagonal ducts. We detail two approaches and we discuss their limitations in practical circumstances encountered during the design process of a structure for determination of fluid and flow characteristics. The simple applicability of the inferred formulas contrasts with the classical and huge time consuming numerical approaches, these formulas being suitable tools in the design process of the structure operating in the micro world. The results presented in this paper might be adapted for similar structures operating in the macro world as well as for many other situations where devices containing ducts having various non-circular cross sections are present.