Contact

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Education

• 2018 - 2023: Ph.D., Mechanical Engineering, Vanderbilt University, Nashville, TN
• 2014 - 2018: B.S., Mechanical Engineering, Rensselaer Polytechnic Institute (RPI), Troy, NY

Projects

• Simulation and Robotics for Accelerating Minimally Invasive Training and for Enhanced Skill Assessment
• In-Situ Collaborative Robotics in Confined Spaces

Research Interests

• Collaborative robotics
• Continuum robotics
• Human-robot interaction
• Robot safety
• Surgical robotics
• Mechanisms

Awards

• First Place. 2021 ASME Student Mechanism and Robotics Design Competition (SMRDC). [link]

Peer-Reviewed Journal Papers

• R. Natarajan, G.L.H. Johnston, N. Simaan, M. Likhachev, and H Choset, "Long Horizon Planning through Contact using Discrete Search and Continuous Optimization," IEEE Transactions on Robotics. In revisions.
• G.L.H. Johnston, N. Shihora, and N. Simaan, "A Modal-Space Formulation for Momentum Observer Contact Estimation and Effects of Uncertainty for Continuum Robots," International Journal of Robotics Research. doi: 10.1177/0278364925134282. Accepted.
• G.L.H. Johnston, A.L. Orekhov, and N. Simaan, "Design Considerations and Robustness to Parameter Uncertainty in Wire-Wrapped Cam Mechanisms," ASME Journal of Mechanisms and Robotics. Feb. 2023. 16(2): 021001 [video][arXiv] 
• C. Abah, A.L. Orekhov, G.L.H. Johnston, and N. Simaan, "A Multi-Modal Sensor Array for Human-Robot Interaction and Confined Spaces Exploration Using Continuum Robots." IEEE Sensors Journal, 2022. 22 (4), 3585-3594. [video]

Peer-Reviewed Conference Papers

• A. Shahbazi, K. Pereira, J. Heiselman, E. Akbari, A. Benson, S. Seifi, G.L.H. Johnston, X. Liu, E.
  Terpstra, A. Draaisma, J.J. Severs, N. Simaan, M. Miga, and S. Kolouri, “Neural-Augmented Kelvinlet:
  Real-Time Soft Tissue Deformation with Multiple Graspers.” The 28th International Conference on
  Medical Image Computing and Computer Assisted Intervention (MICCAI 2025). Submitted.
• J. Atoum, G.L.H. Johnston, N. Simaan, and J.Y. Wu, “Multi-Modal Gesture Recognition from Video
  and Surgical Tool Pose Information via Motion Invariants,” 2025 International Symposium on Medical
  Robotics (ISMR). Accepted. [arXiv]
• M. Veliky, G. L. H. Johnston, A. Yildiz and N. Simaan, "A Feasibility Study of a Soft, Low-Cost, 6-Axis Load Cell for Haptics," 2024 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Abu Dhabi, United Arab Emirates, 2024, pp. 2339-2346, doi: 10.1109/IROS58592.2024.10802018. [arXiv]
• G. Del Giudice, G.L.H. Johnston, and N. Simaan. "Design Considerations for 3RRR Parallel Robots with Lightweight Static-Balancing." ASME 2023 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference (IDTEC/CIE). [arXiv]
• A.L. Orekhov, G.L.H. Johnston, and N. Simaan, "Task and Configuration Space Compliance of Continuum Robots via Lie Group and Modal Shape Formulations," 2023 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS). [arXiv]
• R. Natarajan, G.L.H. Johnston, N. Simaan, M. Likhachev, and H Choset, "Torque-Limited Manipulation Planning through Contact by Interleaving Graph Search and Trajectory Optimization," IEEE International Conference on Robotics and Automation (ICRA). 2023. [arXiv]
• G.L.H. Johnston, A.L. Orekhov, and N. Simaan. "Kinematic Modeling and Compliance Modulation of
  Redundant Manipulators Under Bracing Constraints." IEEE International Conference on Robotics and Automation (ICRA), May 2020.
• C. Abah, A.L. Orekhov, G.L.H. Johnston, P. Yin, H. Choset, and N. Simaan. "A Multi-modal Sensor Array for Safe Human-Robot Interaction and Mapping." IEEE International Conference on Robotics and Automation (ICRA). May 2019. [video]

Conference Abstracts

• G.L.H. Johnston, A. Yildiz, K. Pereria, A. Shahbazi, J. Atoum, J. Heiselman, E. Akbari, A. Benson, X. Liu, E. Terpstra, A. Draaisma, J.J. Severs, R. Kauffmann, J.Y. Wu, S. Kolouri, M.I. Miga, K. Idrees, and N. Simaan, “Towards A Haptically-Enabled Training Platform for Accelerating Laparoscopic Skill Acquisition in Developing Countries” The 36th Annual International Society for Medical Innovation and Technology (SMIT 2025). Washington DC. Submitted.

Workshop Presentations 

• R. Natarajan, G.L.H. Johnston, N. Simaan, M. Likhachev, and H Choset, "Long-Horizon Torque-Limited Planning through Contact using Discrete Search and Continuous Optimization" in IROS 2023 Workshop on Leveraging Models for Contact-Rich Manipulation. Accepted for Spotlight Talk. [pdf]
• A. L. Orekhov, G.L.H. Johnston, C. Abah, H. Choset, and N. Simaan, “Towards Collaborative Robots with Sensory Awareness: Preliminary Results Using Multi-Modal Sensing,” in ICRA 2019 Workshop "Physical human-robot interaction: a design focus," May 2019. [video] 

Past Experience

• Summer 2017: Intern, Biorobotics Lab, The Robotics Institute at Carnegie Mellon University,  Pittsburgh, PA
• Summer 2016: NSF REU Student, ARMA Lab, Vanderbilt University, Nashville, TN
• Summer 2015: NSF REU Student, ARMA Lab, Vanderbilt University, Nashville, TN