## Krishnaprasad, P. S.

The Institute for Systems Research

Maryland Robotics Center

Brain and Behavior Institute

P. S. Krishnaprasad received his Ph.D. degree from Harvard University in 1977. He was on the faculty of the Systems Engineering Department at Case Western Reserve University from 1977 to 1980. He has been with the University of Maryland since August 1980, where he has held the position of Professor of Electrical Engineering since 1987, and a joint appointment with the Institute for Systems Research since 1988. He is also a faculty member of the Program in Applied Mathematics and Statistics, and Scientific Computation, and the Program in Neuroscience and Cognitive Science. Since 1987 he has led the Intelligent Servosystems Laboratory.

Krishnaprasad has held short and long term visiting positions with Erasmus University (Rotterdam); the Department of Mathematics, University of California, Berkeley; the University of Groningen (the Netherlands); the California Institute of Technology; the Mathematical Sciences Institute at Cornell University; and the Mechanical and Aerospace Engineering Department at Princeton University.

Krishnaprasad's research interests lie in the broad area of geometric control theory and its applications. His past contributions include geometry of parametrization problems in linear systems, the Lie algebraic foundations of certain nonlinear filtering problems pertaining to system identification, the Lie theory and stability of interconnected mechanical systems (e.g., spacecraft with elastic attachments, spinning rotors, and fluid-filled cavities), and symmetry principles in nonlinear control theory. He has also investigated mathematical problems in the kinematics and control of robot manipulators, the real-time control of flexible robot arms with end-point sensing, tactile perception, and the development of symbolic algebraic tools for design and control. In the last several years, his interests have drawn him to: problems of modeling, design, motion planning and control, arising in mobile robotics (legged and wheeled vehicles, autonomous underwater vehicles and autonomous aircraft); geometric methods in nonlinear dynamics; wavelet analysis for signals and systems; intelligent control architectures, in part inspired by biological paradigms such as central patterns generators and neural networks; the technology and theory of smart materials such as piezo-electric and magnetostrictive materials for use in actuation and sensing; problems of integration of actuators and sensors in control networks; and modeling, simulation, monitoring and control in semiconductor manufacturing processes, such as rapid thermal chemical vapor deposition.

A central interest in geometric control theory, geometric mechanics, Lie groups, and distributed parameter systems, guides the technical approaches taken to attack problems in the above areas. Additionally, some of this work is also linked to the experimental efforts in the Intelligent Servosystems Laboratory.

P. S. Krishnaprasad was elected a Fellow of the IEEE in 1990 for his contributions to geometric and nonlinear control and engineering education. He was appointed a 1998-2000 Distinguished Faculty Research Fellow of the University of Maryland. He was a member of a team recognized by American Helicopter Society's Grover E. Bell Award (2002) (for work on smart structures during 1991-96) bestowed on the Alfred Gessow Rotorcraft Research Center. He was the Munich Mathematical Colloquium Lecturer (October 24, 2006). He is the recipient of the 2007 Hendrik W. Bode Lecture Prize of the IEEE Control Systems Society, for fundamental contributions to the theory of control of natural and synthetic physical systems.

**Honors and awards**

• IEEE Control Systems Society Hendrik W. Bode Prize (2007)

• Distinguished Faculty Research Fellow (1998-2000)

• Outstanding Systems Engineering Faculty Award, Institute for Systems Research, University of Maryland (1990-1991)

• IEEE Fellow (1990)

Geometric control theory and filtering theory; control of infinite dimensional systems; system identification and model reduction; geometric mechanics; dynamics of nonholonomic systems with symmetries; dynamical systems on Lie groups and optimal trajectory generation

Control problems arising in complex multi-body systems (e.g. spacecraft with deformable elastic attachments and fluid filled containers, underwater vehicles)

Problems of modeling, design, motion planning and control, arising in mobile robotics and robotic manipulation; sensors and actuators for robotic end-effectors; motion control for nonholonomic robots; under-actuated autonomous robotic vehicles; GPS-aided navigation of mobile robots

Time-frequency methods for the analysis of signals and systems (e.g. wavelet basis representations); exploitation of auditory-physiological insights in time-frequency analysis of acoustic data; independent component analysis;

Intelligent control architectures for complex systems inspired in part by biological paradigms such as central pattern generators, and space maps associated to auditory and other sensory modalities; learning binaurally directed movement; sensorimotor feedback in echo-locating bats; hybrid models for networks of sensors and actuators; languages for motion control

Technology of smart materials such as piezo-electric and magnetostrictive materials for use in actuation and sensing; nonlinear problems in such materials; hysteresis modeling and compensation; integration of such materials in structures (e.g. networking); computational methods in ferromagnetism with applications to the design of Terfenol-D actuators

Intelligent processing of materials with a special focus on semiconductor manufacturing; modeling, simulation, monitoring and control in semiconductor manufacturing processes, such as rapid thermal chemical vapor deposition; epitaxial growth of thin films and surface reconstruction in epitaxy

Dynamics and control of formations, swarming, flocking and related biological phenomena; acoustics and biological signal processing; pursuit phenomena and prey capture behavior in nature; evolutionary game-theoretic basis for strategies of pursuit; analysis of field data on starling flocks; inverse problem of reconstructing interaction laws for collectives; cognitive cost of flocking as measured by generative models from data; continuum models of flocks

Subriemannian geometry and optimal control in the study of collectives, and for the design of efficient, nanoscale heat engines; critical dynamics in field theory and related optimal control problems

The research interests described above are supported by a program of experimental investigations in the **Intelligent Servosystems Lab** (ISL) where, in the period 1986 – 2019, the projects included; experiments in positioning, vibration suppression and impact control of a flexible arm with embedded actuators; mechanical manipulation with a modular hand invented in ISL; a hybrid (piezoelectric-magnetostrictive) motor invented in ISL; nonholonomic robot design; a parallel linkage manipulator invented in ISL; 3-D solid modeling and graphical animation; and motor networks. The **primary current emphasis** in ISL is on mobile robotics and software for control of collectives of robots. A Vicon motion capture system was installed in 2013 to study collective behavior of robots, and is used to validate principles and algorithms applicable to biological and robotic collectives

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Alumnus Matteo Mischiati is lead author of sensorimotor control study in *Nature*

Research shows dragonflies use predictive control strategies, not just simple reactions, to capture prey.
- Fellow, 1990