Resume

• 1995

  Doctor of Philosophy - PhD

  Agricultural Engineering

  University of Illinois at Urbana-Champaign

• 1991

  Masters of Science

  Electrical Engineering

  South Dakota State University

• 1985

  Bachelor's degree

  Electrical Engineering

  South Dakota State University

• Technical Writing

  Research

  Matlab

  Higher Education

  Fluid Power Education

  Fluid power engineering

  Modeling and Simulation

  agricultural engineering

  Dielectric spectroscopic sensing of fine liquid droplets in an airstream

  Stuart J Birrell

  Safal Kshetri

  Contamination of compressed air can reduce its utility and lead to costly failure of pneumatic\ncomponents. Monitoring contaminants in the compressed air could help take preventive\nmeasures to maintain usefulness of the pneumatic systems. Dielectric spectroscopy has good\npotential as a viable commercial sensor technology for pneumatic systems as it can differentiate\ndielectric properties of the air with and without contaminants. It could also be used to detect the\npresence of oil mist

  required for lubricating pneumatic components. Two tests were performed\nusing a sensor capable of measuring the dielectric spectrum of the fluid mixture. The objective\nwas to investigate the efficacy of dielectric spectroscopy in detecting the presence of deionised\nwater and light lubricant oil in an airstream. These liquids were atomised using industrial\nspray nozzles

  then entrained in an airstream and passed through the sensor. Spectroscopic\nmeasurements were acquired and multivariate classifiers were developed using principal\ncomponent analysis and linear discriminant analysis to investigate the sensor’s performance in\ndifferentiating the presence and absence of liquid droplets in the airstream. The classifier was\nable to separate the two cases suggesting dielectric spectroscopy could be used to detect these\ntwo liquids in an airstream.

  Dielectric spectroscopic sensing of fine liquid droplets in an airstream

  Michael C. Dorneich

  Yu Du

  To advance construction machine design and testing

  model-based design and virtual operator models (VOMs) can be used to explore machine designs virtually. However

  current VOM efforts have been restricted to mimicking known trajectories

  recorded from actual machine operations. Previous work developed a VOM to use in closed-loop simulation with an excavator model. To advance the utility of model-based machine testing

  the fidelity of the VOM was enhanced along three lines: 1) representation of expert work cycle operation

  2) adaptation to changes in work site environment and 3) adaptation to changes when operating different machines. To represent expertise

  work cycle task overlap was modeled – a hallmark of expert human operator performance. A mental model was developed to adapt to changes in the work site environment. Finally

  the VOM was generalized to adapt to changes in excavator dimensions

  eliminating the need for time intensive “tuning” typical of trajectory-dependent models. Three case studies demonstrated task overlap modeled productivity gains typical of expert operators

  VOM control outputs adapted as trench depth and pile height increased

  and the VOM adapted to different excavator models automatically. An additional case study compared VOM results to human-recorded data. This work advances the ability to integrate human expertise and adaptability in virtual operator modeling

  resulting in a more realistic simulation of operations.

  Modeling expertise and adaptability in virtual operator models

  Mehari Tekeste

  Lie Tang

  Jafni J. Jiken

  Safal Kshetri

  HIGHLIGHTS\nThe width of soil disturbance by a single tine depended on and increased with tine diameter and working depth.\nThe single tine potential weeding rate increased with increasing tine diameter

  working depth

  and travel speed. \nThe potential weeding rate of a rotating tine mechanism increased with increasing depth and rotational speed. \nKeywords. Inter-row weeding

  Intra-row weeding

  Mechanical weeding

  Rotating tine mechanism

  Soil disturbance

  Tine.

  Investigating effects of interaction of single tine and rotating tine mechanism with soil on weeding performance using simulated weeds.

  Brian

  Universidade Federal de Viçosa

  Iowa State University

  Raven Industries

  Sioux Falls

  South Dakota Area

  Design Engineer

  Raven Industries

  Viçosa Area

  Brazil

  Visiting Professor in the Departamento de Engenharia Agrícola at Universidade Federal de Viçosa doing research and teaching dynamical systems modeling and simulation.

  Fulbright Fellow

  Universidade Federal de Viçosa

  Iowa State University