Archives—February 2011

Consumer Needs Engineering: Incorporating Perceptual Aspects of Human Assessment in Product Decisions

Thursday February 24, 2011 4:00-5:00 p.m.
ME-EM building, Room 112

Dr. John Cafeo
GM -Vehicle Development Research Lab

A critical need in designing a consumer product, like an automobile, is the use of credible
quantitative models early in the vehicle design process that quantify the risk of consumer
acceptance given a particular vehicle design. In order to quantify the risk, it is necessary
to be able to predict consumer assessments of a vehicle design as well as estimate the
probability a consumer will assess the design in the same way as the prediction. By
aggregating the risk, the vehicle development teams can logically and defensibly balance,
or tradeoff, the various design attributes and features in order to target a vehicle at the
desired population of customers.

In this talk, I will define this area of work and discuss the challenges in modeling a
perception of an attribute of the vehicle. An intertwined concept is human decision
making. I will discuss the large framework for decisions to help motivate the work. The
development of a model will necessary include a description of the product as well as a
description of the people. Currently, data for this type of model comes from consumer
clinics and surveys. Augmenting this data with anthropometric data as well as
physiological data may allow the estimation of a better model. Because gathering this
type of data is expensive, it is important to be able to use data from multiple events. I will
show an example of a model for head clearance to show one way this might be done.

Volumetric 3-component Velocimetry Measurements near a Rushton Turbine in a Stirred Tank Reactor

Thursday February 17, 2011 4:00-5:00 p.m.
ME-EM building, Room 112

Associate Professor Kendra Sharp
Oregon State University

Prof. Sharp’s presentation will focus on three-dimensional measurements of the flowfield in a stirred tank reactor, however, several other current projects will also be briefly introduced. These projects include: induced-charge electroosmosis for flow control in microchannels; a microchannel-based dialyzer; high-Reynolds number flow in a 90° bend; and ‘ micro’-hydro power for rural electrification.

Volumetric 3-component velocimetry measurements have been taken of the flow field near a Rushton turbine in a stirred tank reactor. This particular flow field is highly unsteady and three-dimensional, and is characterized by a strong radial jet, large tank-scale ring vortices, and small-scale blade tip vortices. The experimental technique uses a single camera head with three apertures to obtain approximately 15,000 three-dimensional vectors in a cubic volume. These velocity data offer the most comprehensive view to date of this flow field, especially since they are acquired at three Reynolds numbers. Mean velocity fields and turbulent kinetic energy quantities are calculated. The volumetric nature of the data enable tip vortex identification, vortex trajectory analysis, and calculation of vortex strength. Three identification methods for the vortices are compared. The visualization of tip vortices up to 140 degrees past blade passage in the highest Reynolds number case is notable and has not previously been shown.

A Laboratory for Dynamic Systems and Human-Robot Interface

Thursday February 3, 2011 4:00-5:00 p.m.
ME-EM building, Room 112

Assistant Professor Mohammad Rastgaar
Michigan Technological University

In this talk, I will introduce two areas of my research at Michigan Tech. In the first part, “Orthogonal Eigenstructure Control for Active Vibration Cancellation”, I will present Orthogonal Eigenstructure Control (OEC) and its application to structural vibration cancellation. OEC is a feedback control method applicable to general multi-input multi-output linear systems. While the available control design methodologies for large flexible structures offer a large and complex design space of options, this control methodology offers a significant simplification of the design task while still allowing some experience-based design freedom. Specifically, OEC eliminates the need for shaping and defining the desirable eigenstructure as required in eigenstructure assignment methods. The mathematical aspects of orthogonal eigenstructure control as well as the results of implementing this method to cancellation of vibrations in a steel test plate under tonal and wideband disturbances will be presented. In the second part of the talk, “Stochastic Estimation of Multi-variable Human Ankle Mechanical Impedance”, I will present a lower extremity rehabilitation robot and the results of estimation of multi-variable dynamic ankle impedance in humans with different types of muscle activities utilizing this robot. The results suggest that different dynamics may govern standing and walking which needs to be considered in the design of lower-extremity assistive or prosthetic robots.