Journal
I. Harris, E. Rouse, R. D. Gregg, G. C. Thomas, “A Control Framework for Accurate Mechanical Impedance Rendering with Series-Elastic Joints in Prosthetic Actuation Applications,” IEEE Robotics and Automation Letters, vol. 9, no. 8, pp. 6983-6990, August 2024. [IEEE]
T.-W. Hsu, R. D. Gregg, G. C. Thomas, “Robustification of Bayesian-Inference-Based Gait Estimation for Lower-Limb Wearable Robots,” IEEE Robotics and Automation Letters, vol. 9, no. 3, pp. 2104-2111, March 2024. [IEEE]
Z. Bons, G. C. Thomas, L. Mooney, E. J. Rouse, “An Energy-Dense Two-Part Torsion Spring Architecture and Design Tool,” IEEE/ASME Transactions on Mechatronics, vol. 29, no. 3, pp. 2373-2384, June 2023. [IEEE]
R. L. Medrano, G. C. Thomas, D. Margolin, E. J. Rouse, “The Economic Value of Augmentative Exoskeletons and their Assistance,” Communications Engineering, vol. 2, article number 43, July 2023, doi: 10.1038/s44172-023-00091-2. [Nature] [Editors’ Choice 2023 !]
R. L. Medrano, G. C. Thomas, C. G. Keais, E. Rouse, R. D. Gregg, “Real-Time Phase and Task Estimation for Controlling a Powered Ankle Exoskeleton on Extremely Uneven Terrain,” IEEE Transactions on Robotics, vol. 39, no. 3, pp. 2170-2182, June 2023, doi: 10.1109/TRO.2023.3235584. [IEEE] [YouTube] [ArXiv]
R. L. Medrano, G. C. Thomas, E. J. Rouse, R. D. Gregg, “Analysis of the Bayesian Gait-State Estimation Problem for Lower-Limb Wearable Robot Sensor Configurations,” IEEE Robotics and Automation Letters vol. 7, no. 3, pp. 7463 – 7470, July 2022, doi: 10.1109/LRA.2022.3183790. [IEEE]
J. Lin, N. V. Divekar, G. C. Thomas, R. D. Gregg, “Optimally Biomimetic Passivity-Based Control of a Lower-Limb Exoskeleton Over the Primary Activities of Daily Life,” IEEE Open Journal of Control Systems, vol. 1, pp. 15 – 28, Apr. 2022, doi: 10.1109/OJCSYS.2022.3165733. [IEEE]
C. Nesler, G. C. Thomas, N. Divekar, E. J. Rouse, R. D. Gregg, “Enhancing Voluntary Motion with Modular, Backdrivable, Powered Hip and Knee Orthoses,” IEEE Robotics and Automation Letters, vol. 7, no. 3, pp. 6155-6162, July 2022, doi: 10.1109/LRA.2022.3145580. [IEEE]
R. L. Medrano, G. C. Thomas, E. Rouse, “Can humans perceive the metabolic benefit provided by augmentative exoskeletons?” Journal of NeuroEngineering and Rehabilitation, vol 19, no. 26, February 2022, doi: 10.1186/s12984-022-01002-w [Springer]
R. L. Medrano, E. Rouse, and G. C. Thomas, “Biological Joint Loading and Exoskeleton Design,” IEEE Transactions on Medical Robotics and Bionics, vol. 3, no. 3, pp. 847-851, July 2021. [IEEE] [CodeOcean]
G. C. Thomas, O. Campbell IV, N. Nichols, N. Brissonneau, B. He, J. James, N. Paine, and L. Sentis, “Formulating and Deploying Strength Amplification Controllers for Lower-Body Walking Exoskeletons,” Frontiers in Robotics and AI, vol. 8, pp. 295, Sept. 2021. doi: 10.3389/frobt.2021.720231. [Frontiers]
N. Brissonneau, B. He, G. C. Thomas, and L. Sentis, “Biologically-Inspired Impedance Control with Hysteretic Damping,” IEEE Control Systems Letters, vol. 5, no. 5, pp. 1717-1722, Nov. 2021. [IEEE]
G. C. Thomas, J. Mehling, J. Holley, and L. Sentis, “Phase-Relaxed-Passive Full State Feedback Gain Limits for Series Elastic Actuators,” IEEE Transactions on Mechatronics, vol. 26, no. 1, pp. 586-591, Feb. 2021. [IEEE]
B. He, H. Huang, G. C. Thomas, and L. Sentis, “A Complex Stiffness Human Impedance Model with Customizable Exoskeleton Control,” IEEE Transactions on Neural Systems and Rehabilitation Engineering, vol. 28, no. 11, pp. 2468-2477, Nov. 2020. [IEEE]
G. C. Thomas, and L. Sentis, “Quadric Inclusion Programs: an LMI Approach to H[infinity]-Model Identification,” IEEE Transactions on Automatic Control, vol. 64, no. 10, pp.4229-4236, Oct. 2019. [IEEE] [CodeOcean]
K. Isik, G. C. Thomas, and L. Sentis, “A Fixed Structure Gain Selection Strategy for High Impedance Series Elastic Actuator Behavior,” J. Dynamic Systems, Measurement, and Control., vol. 141, no. 2, Oct. 2018, doi: 10.1115/1.4041449 [Link]
D. Kim, Y. Zhao, G. C. Thomas, and L. Sentis, “Stabilizing Series-Elastic Point-Foot Bipeds Using Whole-Body Operational Space Control,” IEEE Trans. Robot., vol. 32, no. 6, pp. 1362-1379, Dec. 2016. [Finalist, Best WBC Paper 2016] [IEEE]
T. Koolen, S. Bertrand, G. C. Thomas, T. de Boer, T. Wu, J. Smith, J. Englsberger, and J. E. Pratt, “Design of a Momentum-Based Control Framework and Application to the Humanoid Robot Atlas,” Int. J. Humanoid Robot., 13, 1650007, Mar. 2016. [Winner, IJHR 2016 Best Paper Awards] [Finalist, Best WBC Paper 2016] [Link]
Conference
N. D. Rawal, R. L. Medrano, G. C. Thomas, E. J. Rouse, “A Sensitivity Analysis of an Economic Value Metric for Quantifying the Success of Lower-Limb Exoskeletons and Their Assistance,” 2023 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), pp. 4168-4175, doi: 10.1109/IROS55552.2023.10342452. [IEEE]
K. Walters, G. C. Thomas, J. Lin, R. D. Gregg, “An Energetic Approach to Task-Invariant Ankle Exoskeleton Control,” 2023 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), pp. 6082-6089, doi: 10.1109/IROS55552.2023.10342136. [IEEE]
J. A. Montes-Pérez, G. C. Thomas, R. D. Gregg, “Effects of Personalization on Gait-State Tracking Performance Using Extended Kalman Filters,” 2023 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), pp. 6068-6074, doi: 10.1109/IROS55552.2023.10342498. [IEEE]
Z. Bons†, G. C. Thomas†, L. Mooney, E. J. Rouse, “The design of a compact, two-part torsion spring architecture,” in 2023 IEEE Conference on Robotics and Automation (ICRA), pp. 7461-7467 †—co-first authors. [IEEE]
G. C. Thomas, R. D. Gregg, “An Energy Shaping Exoskeleton Controller for Human Strength Amplification,” in 2021 IEEE Conference on Decision and Control, pp. 1419-1425, doi: 10.1109/CDC45484.2021.9682793 [IEEE]
E. Bolívar-Nieto, G. C. Thomas, E. Rouse, R. D. Gregg, “Convex Optimization for Spring Design in Series Elastic Actuators: From Theory to Practice,” in 2021 IEEE/RSJ International Conference on Intelligent Robotics and Systems, pp. 9327-9332, 2021. [IEEE]
R. Medrano, G. C. Thomas, E. Rouse, “Methods for Measuring the Just Noticeable Difference for Variable Stimuli: Implications for Perception of Metabolic Rate with Exoskeleton Assistance,”at The 8th IEEE RAS/EMBS International Conference for Biomedical Robotics and Biomechatronics, pp. 483-490, New York City, NY, 2020 [IEEE]
B. He, G. C. Thomas, L. Sentis, “Robust Estimator-Based Safety Verification: A Vector Norm Approach,” 2020 American Control Conference (ACC), pp. 3419-3424. IEEE, 2020. [IEEE]
H. Huang, H. Cappel, G. C. Thomas, B. He, L. Sentis, “Adaptive Compliance Shaping with Human Impedance Estimation,” in 2020 American Control Conference (ACC), pp. 3419-3424. IEEE, 2020. [IEEE]
G. C. Thomas, J. M. Coholich, and L. Sentis, “Compliance Shaping for Control of Strength Amplification Exoskeletons with Elastic Cuffs,” presented at The IEEE/ASME International Conference on Advanced Intelligent Mechatronics, Hong Kong, China, 2019 [IEEE]
B. He, H. Huang, G. C. Thomas, and L. Sentis, “Complex Stiffness Model of Physical Human–Robot Interaction: Implications for Control of Performance Augmentation Exoskeletons,” in The 2019 IEEE/RSJ International Conference on Intelligent Robots and Systems, Macau, China, 2019 [IEEE]
B. He, G. C. Thomas, N. A. Paine, and L. Sentis, “Modeling and Loop Shaping of Single-Joint Amplification Exoskeleton with Contact Sensing and Series Elastic Actuation,” presented at The American Control Conference, Philadelphia, PA, 2019 [IEEE]
R. Schlossman, G. C. Thomas, O. Campbell, and L. Sentis, “Toward Exploiting the Natural Dynamics of Series Elastic Robots by Actuator-Centered Sequential Linear Program,” in The IEEE International Conference on Robotics and Biomimetics, Kuala Lumpur, Malaysia, 2018, doi: 10.1109/ROBIO.2018.8665239 [IEEE]
G. C. Thomas, B. He, and L. Sentis, “Safety Control Synthesis with Input Limits: a Hybrid Approach,” in The American Control Conference, Milwaukee, WI, 2018 [IEEE]
G. C. Thomas, and L. Sentis, “MIMO Identification of Frequency-Domain Unreliability in SEAs,” in The American Control Conference, Seattle, WA, 2017 [Link]
P. Rao, G. C. Thomas, L. Sentis, and A. Deshpande “Analyzing Achievable Stiffness Control Bounds of Robotic Hands With Compliantly Coupled Finger Joints,” presented at IEEE Conference on Robotics and Automation, Singapore, 2017 [Winner, Best ICRA 2017 Manipulation Paper] [Link]
G. C. Thomas, and L. Sentis, “Towards Computationally Efficient Planning of Dynamic Multi-Contact Locomotion,” in The IEEE/RSJ International Conference on Intelligent Robots and Systems, Daejeon, South Korea, 2016, doi: 10.1109/IROS.2016.7759571 [Link]
D. Kim, G. C. Thomas, and L. Sentis, “A Method for Dynamically Balancing a Point Foot Robot,” in The 15th IEEE-RAS International Conference on Humanoid Robots, 2015, doi: 10.1109/HUMANOIDS.2015.7363468 [Link]
D. Kim, G. C. Thomas, and L. Sentis, “Continuous Cyclic Stepping on 3D Point-Foot Biped Robots Via Constant Time to Velocity Reversal,” in Control Automation Robotics & Vision (ICARCV), 2014 13th International Conference on., IEEE. 2014, doi: 10.1109/ICARCV.2014.7064561 [Link]
D. Kim, Y. Zhao, G. C. Thomas, and L. Sentis, “Empirical Modifications to a Phase Space Planner which Compensates for Low Stiffness Actuation in a Planar, Point-Foot, Biped Robot,” in ASME 2014 Dynamics Systems and Control Conference, San Antonio, TX, 2014, doi: 10.1115/DSCC2014-6033 [Link]
K.S. Kim, G. C. Thomas, and L. Sentis, “Fully Omnidirectional Compliance in Mobile Robots Via Drive-Torque Sensor Feedback” in IEEE International Conference of Intelligent Robots and Systems, 2014, doi: 10.1109/IROS.2014.6943239 [Link]
T. Koolen, J. Smith, G. C. Thomas, S. Bertrand, J. Carff, N. Mertins, D. Stephen et al., “Summary of team IHMC’s virtual robotics challenge entry,” in Proceedings of the IEEE-RAS International Conference on Humanoid Robots, 2013, doi: 10.1109/HUMANOIDS.2013.7029992 [Link]
G. C. Thomas, C. Gimenez, E. Chin, A. Carmedelle, and A. M. Hoover, “Controllable, High Force Amplification Using Elastic Cable Capstans,” in ASME 2012 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference Volume 4: 36th Mechanisms and Robotics Conference, Parts A and B., Chicago, IL, 2012, pp.885-889. [Link]
E. Culler, G. C. Thomas, and C. L. Lee, “A Perching Landing Gear for a Quadcopter,” in 53rd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, Structures, Structural Dynamics, and Materials and Co-located Conferences., Honolulu, HI, 2012, doi: 10.2514/6.2012-1722 [Link]