Join ASPE

Monday – Friday
October 28 – November 1, 2019
Wyndham Grand Downtown Pittsburgh
Pittsburgh, Pennsylvania, USA

Conference Chair
Stephen J. Ludwick, Aerotech, Inc.
 

Photo Credit: David Reid/VisitPittsburgh

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Tutorials

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Tutorials will be held on Monday-Tuesday, October 28-29, 2019 this year (instead of the usual Sunday-Monday)


Tutorials that will be offered at this year’s conference:

Monday October 28, 2019 (AM Tutorials) 8:00 AM – 12:00 PM

“Dynamic Error Budgeting for Mechatronic Machines”
Dr. Leon Jabben (MI-Partners)
In this course you will learn that dynamic error budgeting (DEB) is not so much about error budgeting but much more about a framework that can be used in designing mechatronic (precision) machines. It is a framework that is based on the modeling of (stochastic) disturbances by means of their Power Spectral Densities and how these propagate through a mechatronic system (with feedback). The impact of the various disturbances are then best compared in a so-called Cumulative Power Spectral plot, which show the cumulative power for each disturbance towards the performance channel of interest over frequency.

Besides predicting the performance, the DEB framework allows in this manner to compare the impact of “incompatible” disturbances with units such as voltage, newton, meter/s etc. Thereby enabling to answer system design questions, for example on whether to focus on a better amplifier, a better floor isolation system, or instead limiting the impact from a specific mechanical resonance.

This course discusses the theory and modeling of disturbances typically found in mechatronic systems, a case study, as well as some notes of attention in applying the framework. Given the limited time, the material shall not be covered fully in-depth, but will focus more on the practical application. A basic understanding of feedback systems and control design is prerequisite.

“Control of Precision Mechatronic Systems”
Dr. David Trumper (MIT)
This tutorial presents key principles for the design and implementation of control systems for precision machines, as well as the interaction of these controllers with system hardware. The topics covered include: PID control laws, and their implementation in analog and digital form, nonlinear effects such as integrator windup, anti-windup, PID tuning, and the limitations of PID as a controller form. We also discuss the more general concepts of loop shaping design via lead and lag compensation, and the implementation of these controllers in analog and digital form. We introduce stability metrics of crossover frequency and phase and gain margins, as well as the Nyquist stability test. The use of the sensitivity function for loop tuning is presented. The value of using a dynamic analyzer to measure loop shaping performance is discussed. Additional topics include the effects of machine stiffness and damping on control performance, and the effects and modeling of quantization and noise. Case studies provide context. Assumed prerequisites include prior experience with control systems in some form, as well as earlier exposure to dynamic systems theory, including the Laplace transform, poles/zeros, and Bode plots.

“Practical Aspects of Diamond Turning”
Dr. Joseph Owen (Raytheon)
John Schaefer (Raytheon)

Diamond turning is an essential manufacturing process used in direct machining of optical surfaces in many areas of photonics. A few examples include: infrared optics (both commercial and defense), plastic injection mold inserts, and mirrors (spectrometers, telescopes, satellite, etc.).
This tutorial will cover the following topics:

  • History of machine tools on the way to ultra-precision
  • Enabling machine tool technologies
  • Machine configurations
  • 2-axis turning, slow and fast tool servo, flycutting and milling
  • Machine errors
  • Machine tool companies
  • Diamond tool basics
  • Single crystal and polycrystalline
  • Geometry
  • Suppliers
  • Diamond Turning materials
  • Metals (D-shell electron phenomena)
  • Brittle materials: Crystals, IR glasses, ceramics
  • Machining parameters
  • Feed rates, depth of cuts, spindle speeds
  • Typical roughing and finishing
  • Surface finish
  • Cutting fluids
  • Basics of optical prescriptions
  • Tool path generation software
  • Metrology
  • Form and finish
  • Advanced diamond machining
  • High speed machining
  • Ultra-sonic
  • Laser assisted

“Passive Damping in High-Tech Systems”
Dr. Kees Verbaan (NTS Systems Development)
The implementation of passive damping is becoming a key knob for getting precision engineering applications to meet tighter specifications over time. In particular for high-tech systems, we see high-bandwidth control of systems that are classically designed for high reproducibility, i.e. based on masses and springs, becoming increasingly difficult. Despite the risk of hysteresis related virtual play, passive damping can highly simplify controller design and improve positioning performance.

This tutorial will address the design, modelling and implementation of passive damping in high-tech systems. We will discuss the trade of between damping on the one hand, and stiffness and position uncertainty on the other. Various passive damping principles will be discussed, viz. material damping (viscous-, linear viscoelastic- and composite damping), tuned mass- and robust mass damping, and constrained- and free-layer damping. We will focus on different application areas, such as medical equipment, machine tools and semiconductor applications.

“Design Principles for Precision Mechanisms – Part 1”
Prof. Dannis M. Brouwer (University of Twente)
Piet C.J. van Rens (Settels Savenije van Amelsvoort)
Susan van den Berg (Hogeschool Fontys)

The Design Principles for Precision Mechanisms tutorial is about the conceptual approach to designing precision mechanisms like manipulators, scientific instruments, precision equipment, etc. It focuses on the mechanical aspects of precision in a mechatronic system context. Extra attention is devoted to essential “details” making the difference between a good and bad design. Both practical and theoretical approaches will be detailed. The analysis of the tutorial subjects will be both intuitively and model-based. Subjects of the tutorial:

  • Design for Stiffness: The energy approach and Optimal material usage.
  • Exact Constraint Design: Analysis methods, practical and mathematical (FACT, Grübler and loop-closure counting) and Static indeterminacy: pro’s and con’s.
  • Flexure Design for Precision: Basic flexure elements; Stages based on flexure elements; Design for stiffness with flexures with a large range of motion; 2D non-linear flexure analysis.
  • Minimizing hysteresis in precision systems: In couplings and sliding motion mechanisms and In clamped flexures.
  • Reference systems: Dealing with accuracies in manufacturing and assembly.

Monday October 28, 2019 (PM Tutorials) 1:30 PM – 5:30 PM

“Basics of Hydrostatic Spindles Theoretical Analysis: Analytical and Numerical Approaches”
Dr. Leonid Kashchenevsky (Elka Precision, LLC)
The goal of this tutorial is to provide a powerful tool and simple algorithms to analyze hydrostatic spindles characteristics using simple analytical expressions. Hydrostatic bearing design is an inherently complicated challenge with 10-15 independent parameters. This tutorial will outline the role of these parameters so that the designer will be able to do their own exploration later. A discussion of the physical processes will be presented after the analytical formulas are derived so that listeners get much better understanding and an intuitive feeling about the influence of spindle parameters on their characteristics. This material will also prepare the designer for their own numerical analysis. The tutorial will highlight some of the practical challenges such as dealing with manufacturing tolerances and variation in material properties such as of oil viscosity, which can vary by up to 15% from the nominal number.

“Introduction to Robust Controls”
Dr. Mark Bedillion (Carnegie Mellon University)
This tutorial introduces the tools and techniques used to design feedback controllers that achieve deterministic performance on uncertain systems. It begins by discussing sources of uncertainty in the dynamic response of mechatronic systems, explaining the difference between structured and unstructured uncertainties, and developing tools for mathematically describing uncertainty in a way that is amenable to feedback control design. The tutorial will then introduce robust control techniques (e.g. control) and demonstrate how they are related to, but distinct from, classical frequency domain loop shaping techniques. Using dynamic models augmented with uncertainty descriptions, we will design feedback algorithms using tools that achieve stability and performance over the entire range of possible responses. Finally, we will demonstrate how the resulting high order controllers can be reduced for practical implementations.

This is a somewhat advanced class in feedback control systems, and it is expected that the attendees will have a basic understanding of linear algebra and frequency domain tuning techniques. Students without such a background are recommended to take “Control of Precision Mechatronic Systems” by Prof. David Trumper prior to joining this tutorial.

“Design Principles for Precision Mechanisms – Part 2”
Prof. Dannis M. Brouwer (University of Twente)
Piet C.J. van Rens (Settels Savenije van Amelsvoort)
Susan van den Berg (Hogeschool Fontys)

The Design Principles for Precision Mechanisms tutorial is about the conceptual approach to designing precision mechanisms like manipulators, scientific instruments, precision equipment, etc. It focuses on the mechanical aspects of precision in a mechatronic system context. Extra attention is devoted to essential “details” making the difference between a good and bad design. Both practical and theoretical approaches will be detailed. The analysis of the tutorial subjects will be both intuitively and model-based.

Subjects of the tutorial:

  • Design for Stiffness: The energy approach and Optimal material usage.
  • Exact Constraint Design: Analysis methods, practical and mathematical (FACT, Grübler and loop-closure counting) and Static indeterminacy: pro’s and con’s.
  • Flexure Design for Precision: Basic flexure elements; Stages based on flexure elements; Design for stiffness with flexures with a large range of motion; 2D non-linear flexure analysis.
  • Minimizing hysteresis in precision systems: In couplings and sliding motion mechanisms and In clamped flexures.
  • Reference systems: Dealing with accuracies in manufacturing and assembly.

“Introduction to Machine Learning for Precision Engineers”
Prof. Amir Barati Farimani (Carnegie Mellon University)
In this entry-level tutorial, we will explore machine learning techniques with the goal of identifying suitable opportunities to use them in problems related to precision engineering. The course assumes no past experience with these techniques, and begins with a review of the terminology and differences and similarities between machine learning, reinforcement learning, deep learning, and artificial intelligence tools. With the the nomenclature demystified, we will next focus on identifying problems for which these tools can provide a benefit. Much of the effort in applying these tools involves data preparation, and the pipelines for working with a data set including cleaning, preparing and loading the data will be taught. We will concentrate mainly on machine learning algorithms, and will explain the difference between supervised and unsupervised learning algorithms. The suitability of each type of machine learning algorithm and their limitations and strength will be discussed. We will go over multiple accuracy metrics and uncertainty quantification for the machine learning predictive models. Finally we will review case studies of interest to the precision engineer.

Tuesday October 29, 2019 (AM Tutorials) 8:00 AM – 12:00 PM

“Large Scale Metrology”
Dr. Ed Morse (University of North Carolina – Charlotte)
Description: From the perspective of a precision engineering, large-scale metrology might span dimensions ranging from about one meter to dimensions exceeding one hundred meters. This tutorial discusses the attributes of both workpieces and instruments that make large-scale metrology different from “traditional” dimensional metrology. The operational principles of the various instruments will be discussed, as well as strategies for utilizing multiple instruments for different aspects of the same measurement. The national and international standards that are used to specify the performance of these instruments will also be covered. The influence of the workpiece on measurement uncertainty is much greater for very large workpieces than for conventional parts – identifying and mitigating these influences is central to effective large scale metrology, and will be discussed in detail.

“Thermal Effects in Mechatronic Systems – Part 1”
Dr. Theo Ruijl (MI-Partners)
Thermal effects are one of the main error sources in precision equipment. The last decades huge improvements have been reached by understanding and controlling these thermal effects and a significant amount of knowledge has been gained. The tutorial will present the state of the art status about thermal design methodology and modeling. A rough outline of the tutorial:

  • Thermal design and modeling is a system approach: How to benefit from thermal considerations in the early stage of design and what competencies are needed to support all the development phases: concept/system design; component/detail design; validation stage.
  • Basic theory on Thermo-mechanics: heat transfer mechanism/thermo-mechanical deformations and dynamic effects.
  • Introduction to modeling techniques: e.g. how to build lump-mass models.
  • Temperature measurement techniques used in precision equipment (different sensor types, challenges at mK level, dynamic behavior, ….).
  • Use case: Ultra-precision measuring machine. This example is used to show different types of thermal design considerations and implementations.
  • Advanced topics:
    • Thermal mode shapes;
    • POD fitting: way to get more info from your measurement results;
    • Dynamic testing instead of steady state testing: the benefit of measuring transient effects to get more info from the system;

In general, the lecture contains many cases (each 10 – 20 min) to practice and make the interaction more active. An active involvement and attitude is highly appreciated.

“Parametric Assessment for Specifying, Calibrating and Verifying Precision Instruments or Machine Tools”
Dr. Jimmie Miller (University of North Carolina – Charlotte)
Procurement and subsequent testing of machine tools requires the buyer and seller to speak the same language. This tutorial reviews international standardized parametrization and tests which are used to specify these machines for procurement or usage including determining when a rebuild or correction may be warranted. Topics include determinism, carriage errors, instrumentation for measuring carriage errors, analysis of acquired data to determine the desired measurand parameters. Other tests such as carriage alignment errors, dynamic errors etc will also be addressed. This tutorial will also be of interest to anyone who uses or builds instruments which have positioning stages.

“Exact-Constraint Design of Precision Flexures – Part 1”
Dr. Jonathan Hopkins (University of California, Los Angeles)
Advanced flexure synthesis principles, modeling approaches, engineering tools, and best practices. Applications: precision motion stages, general purpose flexure bearings, and MEMS/Nano-scale positioning systems. Emphasis on kinematic flexure synthesis using principles of constraint-based design, screw theory, and projective geometry. Lectures, examples, and hands-on exercises involving “build-your-own” flexure kits. Students encouraged to bring flexure examples for analysis and discussion.

Part 1 Overview: (4hrs)

  • Flexible Constraint Theory: Constraint and DOF relationship; exact, over, and underconstraint; modeling flexures using constraint lines; kinematic equivalence
  • Constraints and the Motions they Permit: Modeling translations as rotations; principles of projective geometry in flexure synthesis; rule of complementary patterns; introduction to freedom and constraint spaces as deterministic synthesis tools
  • Freedom and Constraint Topologies (FACT): Designing parallel flexure systems using freedom and constraint spaces.

“Fundamentals of Precision Design”
Dr. Eric Marsh (Penn State University)
This tutorial provides a fast-paced hands-on introduction to rapid precision machine design based on FUNdaMENTAL principles including theory and best practices. Topics include: initial error allocation to enable rapid design, principles of accuracy, repeatability and resolution, bearings, structures, and actuators. Kinematic and elastic averaging-based designs and the implications for bearing life and dynamic performance are stressed with F=kx and ω = sqrt(k/m) as recurring themes throughout the design of a machine. Examples will be presented to show how FUNdaMENTAL principles are critically important for an engineer to understand in order to be able to most effectively use modern design tools such as solid modeling and finite element analysis in the design of precision machines. Attendees are encouraged to bring pencils and paper to learn from solving real problems as part of the lecture.

Tuesday October 29, 2019 (PM Tutorials) 1:30 PM – 5:30 PM

“Parametric Mathematical Modeling of Instruments or Machine Tools For Volumetric Performance Prediction or Process Correction”
Dr. Jimmie Miller (University of North Carolina – Charlotte)
Parametric mathematical models are useful for design error budgeting, manufactured part tolerance prediction with uncertainties, and process correction in various stages of a machines life cycle. Errors in the constrained six-degrees of freedom of carriages generate dimensional errors in a workpiece. This tutorial addresses how to set coordinate frames and measure the errors of the linear or rotary stages of a machine in order to volumetrically assess and correct for those errors. Both vector models with rotation transformation and homogeneous transformation models are addressed for the participant. Uncertainty determination is addressed pending time constraints. This tutorial will also be of interest to anyone who uses or builds instruments which utilize positioning stages

“Introduction to Optomechanical Design”
Dr. Jonathan D. Ellis (University of Arizona)
Many companies and institutes that utilize precision engineering principles interface to optical systems. This may be in the form of optical components, image sensors, detectors, and other types of light analysis. While the link is not explicit, the manner in which optical systems are toleranced is akin to how error budgets are produced for precision system. This is because the tolerances for optical system performance are usually quoted in terms of waves or fractions of a wave, which is traditionally below 1 μm, while the mechanical components used for mounting and alignment are typically designed to 10x-100x worse tolerances. This establishes the fundamental question: how can an optical system be designed to result in fractions of a micrometer of wavefront error when it is held and assembled from components that cannot meet those tolerances?

The material for this tutorial combines elements from two courses on optomechanical engineering taught at the University of Arizona and notes from Daniel Vukobratovich. The expectation is that people taking this tutorial will have some familiarity with basic constraints, free-body force and moment diagrams, statics, and solid mechanics. This half-day tutorial covers the following four parts: Basics of Light & Optical Systems, Lens Specification & Centering, Lens Mounting, and Design for Assembly.

“Exact-constraint Design of Precision Flexures – Part 2”
Dr. Jonathan Hopkins (University of California, Los Angeles)
Advanced flexure synthesis principles, modeling approaches, engineering tools, and best practices. Applications: precision motion stages, general purpose flexure bearings, and MEMS/Nano-scale positioning systems. Emphasis on kinematic flexure synthesis using principles of constraint-based design, screw theory, and projective geometry. Lectures, examples, and hands-on exercises involving “build-your-own” flexure kits. Students encouraged to bring flexure examples for analysis and discussion.

Part 2 Overview: (4hrs)

  • Synthesizing Serial Flexure Systems using FACT: Intermediate freedom spaces; stacking parallel modules; synthesizing parallel and serial elements.
  • Actuating Flexure Systems: Calculating static and dynamic actuation spaces as a way to select the optimal kind, number, location, and orientation of actuators for actuating systems with minimal parasitic error.
  • Case Study Analysis and Discussion: Practice applying FACT to the design of precision flexure systems. Analyze and discuss flexures brought to the course.

No previous experience is required for either part but Part 1 should be taken as a prerequisite to Part 2.

“Error Modeling and Error Budgeting”
Dr. Eric Marsh (Penn State University)
This tutorial is the continuation of the tutorial “Fundamentals of Precision Design“ as it assumes working knowledge of FUNdaMENTAL principles. Starting with the idea of error apportionment as a means to guide development of the overall machine and its component axes, first order analysis is used to fill out a design to meet the required accuracy goals. The initial focus is on geometric, load induced, and thermal errors of the machine in the initial design phase. As the design progresses, an overall error budget is created using a spreadsheet-based model provided. This method helps the designer with selecting machine configurations and components, and tradeoffs to meet the desired performance specification for the machine.

“The New SI”
Dr. Jon Pratt (National Institute of Standards and Technology)
Dr. Stephan Schlamminger (National Institute of Standards and Technology)
Dr. Leon Chao (National Institute of Standards and Technology)
As a precision engineer you’ve probably heard about the “SI redefinition” which goes into effect worldwide on May 20, 2019. It has been described as a “fundamental pivot point in humanity.” But what does it actually mean for us and how we measure?

National Institute of Standards and Technology’s (NIST) own Jon Pratt, Stephan Schlamminger, and Leon Chao will break it all down for us – covering topics ranging from the historical and political underpinnings of the International System of Units, to the very concept of a unit of measure, to the very nature of physical constants and their roles in physics and now measurement. The team will give a glimpse into the future of quantum standards, and they will offer tips on how you too can now realize mass by exploiting well-known concepts of precision engineering.

“Thermal Effects in Mechatronic Systems – Part 2”
Dr. Theo Ruijl (MI-Partners)
Thermal effects are one of the main error sources in precision equipment. The last decades huge improvements have been reached by understanding and controlling these thermal effects and a significant amount of knowledge has been gained. The tutorial will present the state of the art status about thermal design methodology and modeling.

A rough outline of the tutorial:

  • Thermal design and modeling is a system approach: How to benefit from thermal considerations in the early stage of design and what competencies are needed to support all the development phases: concept/system design; component/detail design; validation stage.
  • Basic theory on Thermo-mechanics: heat transfer mechanism/thermo-mechanical deformations and dynamic effects.
  • Introduction to modeling techniques: e.g. how to build lump-mass models.
  • Temperature measurement techniques used in precision equipment (different sensor types, challenges at mK level, dynamic behavior, ….).
  • Use case: Ultra-precision measuring machine. This example is used to show different types of thermal design considerations and implementations.
  • Advanced topics:
    • Thermal mode shapes;
    • POD fitting: way to get more info from your measurement results;
    • Dynamic testing instead of steady state testing: the benefit of measuring transient effects to get more info from the system;

In general, the lecture contains many cases (each 10 – 20 min) to practice and make the interaction more active. An active involvement and attitude is highly appreciated.