Chopra, Nikhil
Professor
Mechanical Engineering
Electrical and Computer Engineering
The Institute for Systems Research
Maryland Robotics Center
Maryland Applied Graduate Engineering
Electrical and Computer Engineering
The Institute for Systems Research
Maryland Robotics Center
Maryland Applied Graduate Engineering
2149 Glenn L. Martin Hall
Dr. Nikhil Chopra is a Professor in the Department of Mechanical Engineering at the University of Maryland, College Park, with an affiliate appointment in the Department of Electrical and Computer Engineering. Before joining the University of Maryland, he was a Postdoctoral Research Associate in the Coordinated Science Laboratory at the University of Illinois at Urbana-Champaign from 2006-2007. He received a Bachelor of Technology (Honors) degree in Mechanical Engineering from the Indian Institute of Technology, Kharagpur, India, in 2001, an M.S. degree in General Engineering in 2003, and a Ph.D. degree in Systems and Entrepreneurial Engineering in 2006 from the University of Illinois at Urbana-Champaign. His research is broadly in systems, control, and robotics. Current research interests include the estimation and control of robotic systems, soft robotics, bilateral teleoperation, and machine learning. He is the co-author of the book Passivity-Based Control and Estimation Networked Robotics. He was previously the Co-Chair of the IEEE Technical Committee on Telerobotics. He was previously an Associate Editor of Automatica, IEEE Transactions on Control of Network Systems, and IEEE Transactions on Automatic Control.
Nonlinear control, Estimation and Control of Robotic Systems, Soft Robotics, Bilateral Teleoperation, and Machine Learning.
Books Authored
- T. Hatanaka, N. Chopra, M. Fujita, and M.W. Spong, Passivity-based Control and Estimation in Networked Robotics, Springer International Publishing, Online ISBN 978-3-319-15171, 2015.
Book Chapters
- T. Hatanaka, N. Chopra, J. Yamauchi and M. Fujita, “A Passivity-Based Approach to Human-Swarm Collaboration and Passivity Analysis of Human Operators,” In Trends in Control and Decision-Making for Human–Robot Collaboration Systems, Y. Wang, F. Zhang (Eds.), Springer, pp. 325-355, 2017.
- Y-C. Liu and N. Chopra, “Control of Robotic Manipulators with Input-Output Delays: An Experimental Verification,” In Experimental Robotics, Springer Berlin Heidelberg, pp. 823-837, 2014.
- P. Tallapragada and N. Chopra, “Lyapunov based Sampling for Adaptive Tracking Control in Robot Manipulators: An Experimental Comparison,” In Experimental Robotics, pp. 683-698. Springer, Heidelberg, 2013.
- Y-C. Liu and N. Chopra, “On Adaptive and Robust Controlled Synchronization of Networked Robotic Systems on Strongly Connected Graphs,” In Flight Formation Control, J. Guerrero and R. Lozano (Eds.), Wiley, March 2012.
- N. Chopra and M.W. Spong, “Output Synchronization of Nonlinear Systems with Relative Degree One,” In Recent Advances in Learning and Control, V.D. Blondel, S.P. Boyd, H. Kimura (Eds.), Lecture Notes in Control and Information Sciences, Springer-Verlag, pp. 51-64, 2008.
- N. Chopra and M.W. Spong, “Passivity-Based Control of Multi-Agent Systems,” in Advances in Robot Control, From Everyday Physics to Human-Like Movements, Sadao Kawamura and Mikhail Svinin, Eds., Springer-Verlag, pp. 107-134, Berlin, 2006.
- N. Chopra, M.W. Spong, R. Ortega, and N.E. Barabanov, “Position and Force Tracking in Bilateral Teleoperation,” Lecture Notes in Control and Information Sciences, Vol. 308, Springer Verlag, Berlin, pp. 269-280, 2004.
Articles in Refereed Journals
- T. Hatanaka, T. Mochizuki, T. Sumino, J. M. Maestre and N. Chopra, "Human Modeling and Passivity Analysis for Semi-Autonomous Multi-Robot Navigation in Three Dimensions," in IEEE Open Journal of Control Systems, Vol. 3, pp. 45-57, 2024.
- K. Chakrabarti, and N. Chopra, “A Control Theoretic Framework for Adaptive Gradient Optimizers,” Automatica, 2024, Volume 160, February 2024, 111466.
- J. N. Twigg, F. Dagefu, N. Chopra and B. M. Sadler, “Robotic Parasitic Arrays for Increased RSS in Non-Line-of-Sight,” IEEE Robotics and Automation Letters, Vol. 7, no. 4, pp. 9167-9174, Oct. 2022.
- N. Chopra, M. Fujita, R. Ortega and M. W. Spong, “Passivity-Based Control of Robots: Theory and Examples from the Literature,” IEEE Control Systems Magazine, Vol. 42, No. 2, pp. 63-73, 2022.
- K. Chakrabarti, N. Gupta and N. Chopra, “On Preconditioning of Decentralized Gradient-Descent When Solving a System of Linear Equations,” IEEE Transactions on Control of Network Systems, Vol. 9, No. 2, pp. 811-822, 2022.
- K. Chakrabarti, N. Gupta, and N. Chopra, “Iterative Pre-Conditioning for Expediting the Gradient-Descent Method: The Case of Distributed Linear Least-Squares Problem,” Automatica, Vol. 137, 110095, 2022.
- K. Chakrabarti, N. Gupta, and N. Chopra, “Robustness of Iteratively Pre-Conditioned Gradient-Descent Method: The Case of Distributed Linear Regression Problem,” IEEE Control Systems Letters, 5(6), pp. 2180-2185, 2020.
- N. Gupta, S. Gade, N. Chopra, and N.H. Vaidya, “Preserving statistical privacy in distributed optimization,” IEEE Control Systems Letters, 5(3), pp. 779-784, 2020.
- T. Liu, S. Azarm, N. Chopra, “Decentralized Multisubsystem Co-Design Optimization Using Direct Collocation and Decomposition-Based Methods. Journal of Mechanical Design, 142(9), 2020.
- J. N. Twigg, N. Chopra and B. M. Sadler, “Communication Maintenance of Robotic Parasitic Antenna Arrays,” IEEE Robotics and Automation Letters, vol. 5, no. 4, pp. 6475-6482, Oct. 2020.
- T. Liu, S. Azarm, N. Chopra, “Integrating Optimal Vehicle Routing and Control With Load-Dependent Vehicle Dynamics Using a Confidence Bounds for Trees-Based Approach." Journal of Dynamic Systems, Measurement, and Control 142.4, 2020.
- Y. Dong and N. Chopra, “Passivity-Based Bilateral Tele-Driving System with Parametric Uncertainty and Communication Delays,” IEEE Control Systems Letters, Vol. 3, No. 2, pp. 350-355, 2019.
- Y. Dong, N. Gupta, and N. Chopra, “False Data Injection Attacks in Bilateral Teleoperation Systems,” IEEE Transactions on Control Systems Technology, Vol. 28, No. 3, pp. 1168-1176, 2020.
- T. Hatanaka, N. Chopra, T. Ishizaki, and N. Li, “Passivity Based Distributed Optimization with Communication Delays using PI Consensus Algorithm,” IEEE Transactions on Automatic Control, Vol. 63, No. 12, 2018.
- M.W.S. Atman, T. Hatanaka, Z. Qu, N. Chopra, J. Yamauchi, and M. Fujita, “Human-enabled Motion Synchronization for Semi-Autonomous Robotic Swarm with a Passivity-short Human Operator," International Journal of Intelligent Robotics and Applications, Vol. 2, No. 2, pp. 235- 251, 2018.
- P.V. Chanekar, N. Chopra, and S. Azarm, “Co-design of Linear Systems using Generalized Benders Decomposition,” Automatica, Vol. 89, pp. 180-193, 2018.
- T. Liu, S. Azarm, N. Chopra, “On Decentralized Optimization for a Class of Multisubsystem Codesign Problems,” ASME Journal of Mechanical Design, Vol. 139, No. 12, pp. 121404-11, 2017.
- T. Hatanaka, N. Chopra, J. Yamauchi, M. Doi, Y. Kawai, M. Fujita, “A Passivity-Based System Design of Semi-Autonomous Cooperative Robotic Swarm,” ASME. Mechanical Engineering, Vol. 139, No. 06, pp. S14-S18, 2017.
- Y. Dong, N. Gupta, and N. Chopra, “Content modification attacks on consensus seeking multi-agent system with double-integrator dynamics,” Chaos: An Interdisciplinary Journal of Nonlinear Science 26.11 (2016): 116305.
- L. Sabattini, C. Secchi, N. Chopra, “Decentralized Estimation and Control for Preserving the Strong Connectivity of Directed Graph,” IEEE Transactions on Cybernetics, Vol. 45, No. 10, pp. 2273-2286, Oct. 2015.
- L. Sabattini, C. Secchi, N. Chopra, “Decentralized Connectivity Maintenance for Networked Lagrangian Systems with Collision Avoidance,” Asian Journal of Control, Vol. 17, No. 1, pp. 111-123, Jan. 2015.
- P. Tallapragada and N. Chopra, “Decentralized Event-Triggering for Control of Nonlinear Systems,” IEEE Transactions on Automatic Control, Vol. 59, No. 12, pp. 3312-3324, 2014.
- Y-C. Liu and N. Chopra, “Gravity Compensation Driven Position Regulation for Robotic Systems under Input-Output Delays,” IEEE Transactions on Control Systems Technology, Vol. 22, No.3, pp. 995-1005, 2014.
- Y-C. Liu and N. Chopra, “On Stability and Regulation Performance for Flexible-Joint Robots with Input/Output Communication Delays,” Vol. 50, No. 6, Automatica, pp. 1698-1705, 2014.
- L. Sabattini*, N. Chopra, and C. Secchi, “Decentralized Connectivity Maintenance for Cooperative Control of Mobile Robotic Systems,” International Journal of Robotics Research, Vol. 32, No.12, pp. 1411-1423, 2013.
- L. Sabattini*, C. Secchi, N. Chopra, and A. Gasparri, “Distributed Control of Robotic Systems with Global Connectivity Maintenance,” IEEE Transactions on Robotics, Vol. 29, No. 5, pp. 1326-1332, 2013.
- Y-C. Liu and N. Chopra, “Synchronization of Networked Mechanical Systems with Communication Delays and Human Input,” ASME Journal of Dynamic Systems, Measurement, and Control, Vol. 135, No. 4, 2013.
- P. Tallapragada and N. Chopra, “On Event-Triggered Tracking for Nonlinear Systems,” IEEE Transactions on Automatic Control, Vol. 58, No. 9, pp. 2343-2348, 2013
- Y-C. Liu and N. Chopra, “Control of Semi-Autonomous Teleoperation System with Time Delays,” Automatica, Vol. 49, No. 6, pp. 1553-1565, 2013.
- N. Chopra, “Output Synchronization on Strongly Connected Graphs,” IEEE Transactions on Automatic Control, Vol. 57, No. 11, pp. 2896-2901, 2012.
- Y-C. Liu and N. Chopra, “Control of Robotic Manipulators under Input-Output Communication Delays: Theory and Experiments,” IEEE Transactions on Robotics, Vol. 28, No. 3, pp. 742-751, 2012.
- Y-C. Liu and N. Chopra, “Controlled Synchronization of Robotic Manipulators in the Task Space,” IEEE Transactions on Robotics, Vol. 28, No. 1, pp. 268-275, 2012.
- N. Chopra and M.W. Spong, “On Exponential Synchronization of Kuramoto Oscillators,” IEEE Transactions on Automatic Control, Vol. 53, No. 4, 2009.
- N. Chopra, M.W. Spong, and R. Lozano, “Synchronization of Bilateral Teleoperators with Time Delay,” Automatica, Vol. 44, No. 8, pp. 2142-2148, 2008.
- N. Chopra, P. Berestesky and M.W. Spong, “Bilateral Teleoperation Over Unreliable Communication Networks,” IEEE Transactions on Control Systems Technology, Vol.16, No. 2, pp. 304-313, 2008.
- N. Chopra, M.W. Spong, R. Ortega, and N.E. Barabanov, “On Tracking Performance in Bilateral Teleoperation,” IEEE Transactions on Robotics, Vol. 22, pp. 861-866, 2006.
University of Maryland Has Strong Presence at ICRA 2024
Researchers detail advancements in navigation, trajectory planning.Congratulations May 2023 ISR graduates!
Here's a list of May graduates with ISR ties---at all degree levels.ISR-affiliated graduates, December 2022
ISR congratulates these students, all advised by ISR faculty!MRC Faculty and Researchers to Present 15 Papers at International Robotics Conference - IROS 2022
15 MRC faculty and researchers to present 15 papers at IROS 2022New system uses machine learning to detect ripe strawberries and guide harvests
Farmers could use the system with computer vision and agricultural robots to reduce waste and increase efficiency.Congratulations ISR Spring 2022 graduates!
We congratulate graduates at all levels who have ISR advisors!Packy, Suriyarachchi, Thompson, Weerakoon, and Young are 2022-2023 MRC GRA Recipients
The MRC Graduate Assistantship Program is open to mid-career UMD Ph.D. students with Maryland Robotics Center advisors.Improving electric scooter-pedestrian safety with better modeling
Researchers with UMD ties develop a modiifed social force model to predict how pedestrians interact with micro-mobility vehicles.Congratulations to our December 2021 ISR graduates!
ISR advisors graduated 22 Ph.D., 2 M.S., and 4 M.S.S.E. new alumni in December!ISR faculty leading, playing key roles in ARL cooperative agreement
The $68M 'ARTIAMAS' research agreement features faculty from UMD and UMBC.UMD Researchers to Have a Strong Showing at ICRA 2021
University of Maryland researchers will present 15 papers at the IEEE International Conference on Robotis and Automation (ICRA 2021) to held on May 30 to June 5, 2021.In memoriam: Dr. Radhakisan Baheti, NSF ECCS Program Director
Dr. Baheti passed away in March and will be greatly missed by ISR, ECE and the Clark School.Stretchable, soft sensing skins for robots
Such skins could equip soft robots with integrated sensing and estimation.MRC Faculty and Researchers to Present 16 Papers at International Robotics Conference - IROS 2020
International Conference on Intelligent Robots and Systems - From 25 October 2020 until 29 November 2020Maryland engineers receive $10M to transform shellfish farming
The team will help farmers tap the economic potential and environmental benefits of shellfish aquaculture.Nikhil Chopra promoted to full professor
The ISR-affiliated faculty member works in control theory and robotics.Maryland Robotics Center launches a new postdoctoral fellowship program
The program will foster multidisciplinary collaborations among Maryland Robotics Center faculty.Haptic Safety for Unmanned Vehicles
UMD research advances networked control and virtual reality for added safety.Nikhil Chopra wins $380K NSF award for robotics
Chopra will investigate the resilience of human-controlled robotic networks to cyber attacks.Nikhil Chopra is PI for NSF EAGER grant for networked 3D printers
The research will develop a fundamental understanding of optimal job assignment in networked 3D printers.Chopra Co-Authors New Book
Associate Professor Nikhil Chopra co-authors Passivity-Based Control and Estimation in Networked Robotics.UMD Robot Visits White House
Grad student Bryan Hays and NAO robot volunteer to teach programming to K-12 students.UAE students, Northrop Grumman engineers tour robotics laboratories
Visitors were in town for the annual AUVSI conference.Nikhil Chopra named to editorial board of leading systems and control journal
Chopra will be an associate editor of IEEE Transactions on Automatic Control.Nikhil Chopra promoted to associate professor with tenure
ISR-affiliated faculty member specializes in networked dynamical systems.Chopra is principal investigator for NSF nonlinear system tracking control grant
The research will enhance the tracking performance of robotic systems under sensor constraints.Miniature Robotics REU students give final presentations
Ten undergrads from around the country give talks on their summer projects.Maryland Robotics Center featured on live TV broadcast
Robots from five research groups help promote Maryland Day activities.Nikhil Chopra receives NSF grant for wireless sensor and robotic networks
Researcher will investigate fundamental issues in control and distributed coordination.REU students spending summer in research
The 12 undergraduate students are participating in NSF's Research Experiences for Undergraduates program.Chopra, Cleaveland, Kanold join ISR this fall
Faculty bring expertise in control, neuroscience and concurrent and distributed systems.- ARTIAMAS Cooperative Agreement
- USDA NIFA: Transforming shellfish farming with smart technology and management practices for sustainable production
- NSF: Resilient Control of Human Controlled Robotic Networks
- Tracking Control of Nonlinear Systems Under Sensing, Computational, and Communication Constraints
- NSF CMMI: Mechanical Phenotyping of Cells: Haptics-Enabled Atomic Force Microscopy
- Fundamental Advances in Control of Wireless Sensor and Robotic Networks