Harvard - Boston University - University of Maryland

Systems Overview

P. S. Krishnaprasad

Department of Electrical Engineering and Institute for Systems Research (ISR) University of Maryland, College Park

November 16, 1999 Presentation for Dr. Randy Zachery, ARO May 25, 2004 at Harvard University

Harvard - Boston University - University of Maryland

Mission Statement

To advance the state-of-the-art in active control of materials andstructures via first-principles modeling, analysis and computation

To enhance the theoretical foundations of controlledfluid-structure interactions at various length scales

To develop the communications and hierarchical control theory needed for controlling very large arrays of sensors and actuators

To develop engineering tools for the design and fabrication ofactuators and sensors based on controllable materials and for theintegration of such devices in structures

Harvard - Boston University - University of Maryland

MARYLAND TEAM

Faculty: Stuart Antman, John Baras, P. S. Krishnaprasad

Post-docs: Dimitrios Hristu, Eric Justh, Ram Venkataraman

Graduate Student Team: Sean Andersson, Babak Azimi-Sadjadi, George Kantor, Andrew Newman, Jin-Qiu Shao, Xiaobo Tan, Fumin Zhang

Recent Ph.D. graduates: Herbert Struemper (1997), VikramManikonda (1997), Eric Justh (1998), Ram Venkataraman (1999)

ARL Collaborator: Mikhail Vorontsov

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GRADUATE EDUCATION

Ph.D. students :

Herbert Struemper (1997), Caltech postdoc, now Entelos;

Vikram Manikonda (1997), now Intelligent Automation;

Eric Justh (1998), UMd-ARL postdoc;

Ram Venkataraman (1999), UMd postdoc; George Kantor (1999), CMU Field Robotics staff;

Andrew Newman (1999), to be Alphatech staff.

Harvard - Boston University - University of Maryland

UNDERGRADUATE EDUCATION

Summer 1998 NSF-REU - Miriam Betnun (MIT '01); vibratory piezo-motor

Summer 1999 NSF-REU - Charles Brubaker (Swarthmore '02), Jacqueline Cockrell (Columbia '02), motion-control integration Shariar Chaudhury (Nebraska '02), Stephanie Wojtkowski (Swarthmore '02);

Summer 1999 NSF-MERIT - Jonathan Wu (RPI), Mohammd Jalloh (George Washington), GPS-integrated motion control Joon-Hoo Lee (Penn State), Norman Lo (UMd), all junior/senior;

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COURSES

A year-long joint course on Analytic and Geometric Approachesto Classical Mechanics and Control Theory, cross-listed between Electrical Engineering and Applied Mathematics (Fall 1997 and Spring 1998) - taught by Antman and Krishnaprasad

Course for high school students during Summer 1998 on sensorsand actuators - taught by Babak Azimi-Sadjadi

Course for NSF-REU students during Summer 1999 on Linear algebra and applications to robot kinematics and control

- taught by Ram Venkataraman

Harvard - Boston University - University of Maryland

OUTREACH

Sharing data and methodology with ETREMA (hysteresis modeling)

Control and Dynamical Systems Invited Lecture Series

http://www.isr.umd.edu/Labs/ISL/events.html

Sharing data and methodology with NSWC - magnetics group

(hysteresis modeling)

Collaboration with ARL Intelligent Optics Lab - Vorontsov group

(nonlinear Zernike filter for wavefront control)

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CURRENT EXTERNAL SUPPORT

CDCSS - Center from Dynamics and Control of Smart Structures (ARO MURI97)

CAAR - Center for Auditory and Acoustics Research (ONR MURI97)

LIS - Learning and Intelligent Systems: Learning Binaurally Directed Movement (NSF97)

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FACILITY

The Intelligent Servosystems Lab is organized to advance the state-of-the art in the design and real-time control of smart systems focusing on advances in

Novel sensing and actuation materials and mechanism designs

New principles for actuation, propulsion, detection,reduction, learning and adaptation

Conceptualizing and prototyping across scales,to sense, actuate, communicate and control

MURI funds lead to enhancement (e.g. dSPACE prototyping system)

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SYSTEMS VIEW

Smart System

Neuroscience

Materials

Intelligent Control

Modeling & Optimization

Wireless

Noise &Sensors

Smart PowerMEMS

Signal Processing

Robotics

Harvard - Boston University - University of Maryland

SYSTEMS VIEW

Smart structures are actively controlled systems with

coordination of actuation and sensing via parallel distributed arrays e.g.,

mobile robot with multiple sensors (MEMS microphones/sonar/GPS)

adaptive optics (LCLV, micromirrors)

remote (wireless) actuation and sensing afford new challenges

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MOTION CONTROL INTEGRATION

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GPS - INTEGRATED CONTROL

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OUR FOCUS

Understand and exploit nonlinearity

Understand and exploit distributed computation and control

Communication/computation patterns for decoupling

Smart materials

Pattern formation

Control patterns for adaptive optics

Harvard - Boston University - University of Maryland

ACCOMPLISHMENTS

Low-order mathematical models of hysteresis nonlinearity (in magnetostrictive actuators) for prediction of performance and real-time control. Meso-scale actuators based on these materials (Terfenol-D) are expected to be useful in control surfaces of aircraft, rotorcraft, and submersibles.

New techniques for high resolution optical phase distortionsuppression (correcting for the effects of atmospheric turbulenceon laser beams) have been developed and tested in simulations.Experimental verification using liquid crystal light valve actuatorsare under way at the Intelligent Optics Laboratory of the ArmyResearch Lab (ARL). This effort is in collaboration with Dr. MikhailVorontsov of ARL. Potential additional applications of this work include optical phase microscopy and wavefront sensing for conventional adaptive optics systems.

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ACCOMPLISHMENTS

New control theory based on pattern formation and communication/computation pattern selection has been developed to realize the potential of the MEMS-scale component technology.

New algorithms for principled reduction of complex nonlinear models have been developed and tested. Techniques for approximate inversion of nonlinear systems for trajectory tracking have been devised in the setting of systems on Lie groups. Related controllability results of use in models that include autonomous ground vehicles have been obtained.

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ACCOMPLISHMENTS

Models of magnetoelastic systems based on the Landau- Lifshitz-Gilbert equations have been investigated from a fundamental mathematical viewpoint as well as from the perspective of numerical computations. Effective predictions of hysteresis curves have been realised setting the stage for a computational actuator design framework based on first-principles models.

Refined dissipation models of importance to numerics have been developed in the context of electro-magneto-solid mechanics. These steps are paving the way for robust software tools for design of actuators.

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PRESENTATIONS TO FOLLOW

Magnetostrictive models (hysteresis/validation/control)

Hysteresis and Numerics (Landau-Lifshitz-Gilbert)

Adaptive Optics (wavefront control)

Patterns and Control (distributed computation and control)

Harvard - Boston University - University of Maryland

ROADMAP FOR THE FUTURE

Exploit the opportunities for (wireless) integratedcontrol in a distributed setting

(Bluetooth as a possible route)

Applications to fluid structure interaction

Micro-microphones, vibratory gyros, inclinometers, and GPS

MEMS-based sensors for integrated motion control

Harvard - Boston University - University of Maryland

ROADMAP FOR THE FUTURE

Develop fully the path from models to software tools

Extend results on magnetoelastic models to thin film MEMS-scale actuators and sensors

Advancement of Zernike filter approach to adaptive optics

Invention disclosure, alternative implementations(e.g. LCLV vs micromirror), and hardware integration