About Me
About Me
Embedded Files
Hi, I'm Hyunjong Song (usually go by Jay). I recently earned my Ph.D. in Mechanical and Aerospace Engineering from New York University. My doctoral research focused on characterizing multi-contact whole-body balancing using balanced state basins and exploring electromechanical motor energy expenditure modeling for energy-efficient control under the guidance of Prof. Joo H. Kim. Prior to my Ph.D., I developed control software for various robots, including manipulators, humanoids, and wheeled robots, while working for companies and laboratories.
Contact/links
Email: hs3927@nyu.edu
CV, Google Scholar, Github, Linkedin
Education
Education
New York University (09/2019 - 08/2024), Brooklyn, New York
Doctorate, Department of Mechanical and Aerospace Engineering
Dissertation: Partition-based balance stability for humanoid robot control and trade-off analyses
Korea University (03/2010 - 02/2012), Seoul, South Korea
Master of Engineering, Department of Mechanical Engineering
Thesis: Development of augmented reality-based surgical navigation system for skull base surgery
Korea University (03/2006 - 02/2010), Seoul, South Korea
Bachelor of Science, Department of Mechanical Engineering
Experience
Experience
New York University (09/2019 - 08/2024), Brooklyn, New York
Graduate Research Assistant at Applied Dynamics and Optimization Lab.
Characterized multi-contact whole-body balancing with balanced state basins.
Studied electromechanical motor energy expenditure modeling for energy-efficient control.
Movensys Inc. (f/k/a Soft Motions and Robotics Inc.) (12/2018 - 09/2019), Suwon, South Korea
Control Software Developer
Developed a control library for industrial manipulators
Hanyang University ERICA (03/2017 - 08/2019), Ansan, South Korea
Software Advisor at HERoEHS Lab.
Developed a walking controller for a soccer robot ALICE.
Developed a motion control framework for a skiing robot DIANA.
Developed control and operation software for a wheel-based performance robot EDIE.
Guided Ph.D. and Master students on their robot control software
ROBOTIS Co., Ltd. (02/2012 - 02/2017), Seoul, South Korea
Research Engineer
Developed motion and walking controllers for humanoid robots (ROBOTIS-OP2 and OP3 and THORMANG series).
Participated in DARPA Robotics Challenge Trial (Team THOR) and Final (Team ROBOTIS).
Designed and developed a Robot-Operating-System-based robot motion control framework.
Developed a numerical-inverse-kinematics-based controller for ROBOTIS-Manipulator.
Developed control software for various robots (dual-arm mobile manipulator, arm wrestler, etc.)
Korea University. (09/2010 - 06/2011), Seoul, South Korea
Teaching Assistant
Integrated Design (MECH45102; Instructor: Prof. Shinsuk Park; Spring 2011)
Computer-Aided Design (MECH35200; Instructor: Prof. Jaekyung Shim; Fall 2010)
My Research and Development
My Research and Development
Efficiency-Stability Trade-off in Humanoid Walking
Hyunjong Song, Sameer A. Upadhye, and Joo H. Kim
Abstract Energy efficiency is another critical factor along with balance stability in the practical deployment of humanoid robots. While they have been extensively studied as separate concerns, their trade-off relationship has received far less attention despite its importance in managing redundancy in humanoid robot walking. This dissertation evaluates energy efficiency using the actuation-squared cost of transport (COT) and assesses balance stability through the newly introduced gait instability metric (GIM). The trade-off relationship between these two metrics with respect to walking speed is then explored. The actuation-squared COT is applied to a Linear Inverted Pendulum Model (LIPM) to approximate humanoid walking dynamics, predicting the trend in energy efficiency with respect to walking speed. Humanoid walking trajectories at different speeds are generated using an existing gait pattern generation algorithm and tested through simulations and experiments. The data collected from these tests are used to compute the actuation-squared COT and the predictions made from the LIPM model are verified. The walking trajectories are also employed to compute balanced state basins and GIMs which identify the relationship between balance stability and walking speeds. Through the individual analyses for energy efficiency and balance stability, the trade-off in humanoid walking is identified.
Hyunjong Song, William Z. Peng, and Joo H. Kim
Abstract Despite the importance and prevalence of loco-manipulation tasks by humanoids, existing criteria and control methods for stability are mostly developed for unloaded legged gait. In this paper, the stability during lifting tasks is comprehensively analyzed to determine the role of the lifted object mass in balancing. The stability of a simple two-degree-of-freedom lifting model and a whole-body humanoid robot are evaluated by constructing their balanced state boundaries, which represent their specific capabilities in maintaining balance, through an optimization-based framework for varying combinations of object mass, joint torque limits, and base of support dimensions. Comparative analysis of the rate of change of the linear and centroidal angular momenta quantifies the nonlinear and nontrivial tradeoffs, i.e., contribution or obstruction, of the effects of the object mass on balancing. Overall, increasing the object mass enhances balance capability subject to the limiting factors of system kinematic and actuation limits, center of pressure within the base of support, friction cone, and unilateral normal contact forces between the feet and the ground.
Hyunjong Song, Gabriel Bronfman, Yunxiang Zhang, Qi Sun, and Joo H. Kim
Abstract The complexity of the control and operation is one of the roadblocks of the widespread utilization of humanoid robots. In this study, we introduce a novel approach to humanoid robot control by leveraging a mixed reality (MR) interface for whole-body balancing and manipulation. This interface system uses an MR headset to track the operator’s movement and provide the operator with useful visual information for the control. The robot mimics the operator’s movement through a motion retargeting method based on linear scaling and inverse kinematics. The operator obtains visual access to the robot’s perspective view augmented with fiducial detection and perceives the current stability of the robot by evaluating the robot’s center-of-mass state in real-time against the precomputed balanced state basin. In real experimental demonstrations, the operator successfully controlled the robot to grasp and lift an object without falling. The common issues in teleoperation with virtual reality headsets, motion sickness and unawareness of their surroundings, are reduced to a low level by using the MR headset with transparent glasses. This study demonstrates the potential of MR in teleoperation with a motion retargeting and stability monitoring method.
Hyunjong Song, William Z. Peng, and Joo H. Kim
Abstract For successful push recovery in response to perturbations, a humanoid robot must select an appropriate stabilizing action. Existing approaches are limited because they are often derived from reduced-order models that ignore system-specific aspects such as swing leg dynamics or kinematic and actuation limits. In this study, the formulation of capturability for whole-body humanoid robots is introduced as a partition-based approach in the augmented center-of-mass (COM)-state space. The 1-step capturable boundary is computed from an optimization-based method that incorporates whole-body system properties with full-order nonlinear system dynamics in the sagittal plane including contact interactions with the ground and conditions for achieving a complete stop after stepping. The 1-step capturable boundary, along with the balanced state boundaries, are used to quantify the relative contributions of different strategies and contacts in maintaining or recovering balance in push recovery. The computed boundaries are also incorporated as explicit criteria into a partition-aware push recovery controller that monitors the robot’s COM state to selectively exploit the ankle, hip, or captured stepping strategies. The push recovery simulation experiments demonstrated the validity of the stability boundaries in fully exploiting a humanoid robot’s balancing capability through appropriate balancing actions in response to perturbations. Overall, the system-specific capturability with the whole-body system properties and dynamics outperformed that derived from a typical reduced-order model.
ALICE at RoboCup 2018
Performance Robot Edie
"Grandma’s Robot" on tvN
THORMANG Demonstration at WRC 2016
THORMANG Demonstration at Humanoid 2015
Humanoid Control with Myo
UR Inverse Kinematics
Augmented-reality-based surgical navigation system for skull base surgery
Master Thesis
Publications
Publications
Journal Articles
Song, H., Upadhye, S.A., and Kim, J.H., “Trade-off Analyses of Energy Efficiency and Balance Stability in Humanoid Gait Control,” (In preparation)
Upadhye, S.A., Yim, J.K., Peng, W.Z., Song, H., and Kim, J.H., “Full-order Stability Basins for Flight-to-Stance Task Control of Jumping Monoped Salto-1P,” (in preparation)
Buglino, C., Peng, W.Z., Ashlyn, S., Song, H., Hillstrom, H.J., and Kim, J.H., “Instantaneous Metabolic Energetics: Data-Driven Modeling Using Function-Based Surrogates and Gradient-Boosting,” (accepted) IEEE Access.
Upadhye, S.A., Yim, J.K., Peng, W.Z., Song, H., and Kim, J.H., “State-Space basins for monopedal jumping with Stable Landing,” ASME Journal of Mechanisms and Robotics, Vol. 17, n 4, 044513, April 2025.
Song, H., Peng, W.Z., and Kim, J.H., “Partition-aware stability control for humanoid robot push recovery,” ASME Journal of Mechanisms and Robotics, Vol. 16, n 1, 011005, January, 2024.
Peng, W.Z., Song, H., Czarkowski, D., and Kim, J.H., “Switched electromechanical dynamics for transient phase control of brushed DC servomotor,” Chaos, Vol. 32, n 12, 123119, 2022.
Peng, W. Z., Mummolo, C., Song, H., and J. H. Kim, “Whole-body balance stability regions for multi-level momentum and stepping strategies,” Mechanism and Machine Theory, Vol. 174, 104880, August 2022.
Park, C., Kim, B., Kim, Y., Eum, Y., Song, H., Yoon, D., Moon, J., and Han, J, “Carved turn control with gate vision recognition of a humanoid robot for giant slalom skiing on ski slopes,” Sensors, Vol. 22, issue 3, January 2022
Peng, W.Z., Song, H., and Kim, J.H., “Stability region-based analysis of walking and push recovery control,” ASME Journal of Mechanisms and Robotics, Vol. 13, n 3, 031103, June 2021.
Bong, J. H., Song, H. J., Oh, Y.J., Park, N.J, Kim, H.M., Park, S.S., “Endoscopic navigation system with extended field of view using augmented reality technology,” The International Journal of Medical Robotics and Computer Assisted Surgery, Vol. 14. n 2, March 2018.
Yi, S.J., McGill, S., Vadakedathu, L., He, Q, Ha, I.Y., Han, J.K., Song, H.J., Rouleau, M., Zhang, B.T., Hong, D., Yim, M., and Lee, D.D, "Team THOR's Entry in the DARPA Robotics Challenge Trials 2013," Journal of Field Robotics, Vol. 32, n.3, January 2015.
Conference Proceedings, Abstracts, and Presentations
Upadhye, S.A., Yim, J.K., Peng, W.Z., Song, H., and Kim, J.H., “State-Space basins for monopedal jumping with Stable Landing,” ASME IDETC/CIE 45th Mechanisms and Robotics Conference, August 25-28, 2024, Washington, DC, USA
Song, H., Bronfman, G., Zhang, Y., Sun, Q., and Kim J.H., “Mixed Reality Interface for Whole-Body Balancing and Manipulation of Humanoid Robot,” International Conference on Ubiquitous Robots, June 24-27, 2024, New York, New York, USA.
Song, H., Peng, W.Z., and Kim, J.H., “Toward stable loaded walking by humanoid,” (video abstract and oral/poster presentations) Dynamic Walking Conference, May 27-30, 2024, Pensacola, Florida, USA.
Upadhye, S.A., Yim, J.K., Peng, W.Z., Song, H., and Kim, J.H., “State-space basins for monopedal jumping with stable landing,” (video abstract and poster presentation) Dynamic Walking Conference, May 27-30, 2024, Pensacola, Florida, USA.
Peng, W.Z., Upadhye, S.A., Song, H., and Kim, J.H., “Gait transition timing: a stability perspective,” (video abstract and poster presentation) Dynamic Walking Conference, May 27-30, 2024, Pensacola, Florida, USA.
Bodmer, S., Song, H., and Kim, J.H., “Partition-aware push recovery prediction and control for general tasks,” (video abstract and poster presentation) Dynamic Walking Conference, May 27-30, 2024, Pensacola, Florida, USA.
Song, H., Peng, W.Z., and Kim, J.H., “Effects of object mass on balancing for whole-body lifting tasks,” IEEE-RAS International Conference on Humanoid Robots, December 12-14, 2023, Austin, TX, USA
Song, H., Peng, W.Z., and Kim, J.H., “Lifting task stability evaluation based on balanced state basins of a humanoid robot,” ASME IDETC/CIE Mechanisms and Robotics Conference, August 20-23, 2023, Boston, MA, USA
Song, H., Peng, W.Z., and Kim, J.H., “Partition-aware stability control for humanoid robot push recovery,” ASME IDETC/CIE Mechanisms and Robotics Conference, August 14-17, 2022, St. Louis, MO, USA
Peng, W.Z., Song, H., and Kim, J.H., “Reduced-order model with foot tipping allowance for legged balancing,” ASME IDETC/CIE Mechanisms and Robotics Conference (virtual), August 17-19, 2021.
Peng, W.Z., Song, H., and Kim, J.H., “Foot tipping allowance in legged balancing with conditional constraints in optimization,” (abstract/poster presentation) Dynamic Walking Conference (virtual), July 15, 2021.
Song, H., Peng, W.Z., and Kim, J.H., “Partition-based stability controller for push recovery,” (abstract/poster presentation) Dynamic Walking Conference (virtual), June 11, 2021.
Peng, W.Z., Song, H., and Kim, J.H., “Stability region-based analysis of walking and push recovery control,” ASME IDETC/CIE Mechanisms and Robotics Conference, August 17-19, 2020, St. Louis, MO, USA (*converted to virtual conference due to pandemic).
Song, H., Peng, W.Z., and Kim, J.H., “Balanced region-based analysis of push recovery control using ankle and hip strategies,” (abstract/poster presentation) Dynamic Walking Conference, May 14, 2020, Hawley, PA, USA (*converted to one-day online conference due to pandemic).
Han, J.K., Yoon, D.K., Kim, B.S., Kim, Y.T., Park, C.Y, Song, H., Eum, Y.S., and Moon, J.I., “Research on Carved Turns of a Skiing Humanoid Robot on a Real-World Slope,” (video) IEEE/RSJ International Conference on Intelligent Robots and Systems, October 1-5,2018, Madrid, Spain.
Shin, S.A., Yoon, D.K., Song, H., Kim, B.S., and Han, J.K., “Communication system of a segmented rescue robot utilizing socket programming and ROS,” International Conference on Ubiquitous Robots and Ambient Intelligence, June 28-July 1, 2017, Jeju, Republic of Korea.
Yi, S.J., McGill, S., Vadakedathu, L., He, Q., Ha, I.Y., Han, J.K., Song, H., Rouleau, M., Hong, and Lee, D.D., "THOR-OP humanoid robot for DARPA Robotics Challenge Trials 2013," International Conference on Ubiquitous Robots and Ambient Intelligence, November 12-15, 2014, Kuala Lumpur, Malaysia.
Lee, S.W., Jung, H.J., Song, H., and Park, S.S., "Development of immersive augmented reality interface system for construction robotic system," International Conference on Control, Automation and Systems, October 27-30, 2010, Goyang-si, Gyeonggi-do, Republic of Korea.
Page updated
Report abuse