About

I am a PhD candidate in the Department of Mechanical Engineering at the University of Illinois Urbana-Champaign. My advisor is Dr. Girish Krishnan in the Monolithic Systems Lab. I am a member of the Artificial Intelligence for Future Agricultural Resilience, Management, and Sustainability Institute (AIFARMS) at UIUC. I also collaborate with researchers at Iowa State University as part of COntext-Aware LEarning for Sustainable CybEr-agricultural (COALESCE) program.

Research interest

I work in robotics and autonomy. I am currently interested in object manipulation and grasping. I am currently working on three projects:

  1. Grasp State Estimation in Agricultural Environments – This work entails an exploration of the sensors and machine learning methods that are effective at estimating the current state of the grasp while harvesting cherry tomatoes. Sensors such as IMU, a tactile sensor, and a custom tension sensor are used with ML models such as a Random Forest classifier and an LSTM classifier to estimate the state of the grasp. The system is trained in the lab and successfully tested on real plants.
  2. Dynamic Modeling and Control of Soft Continuum Actuators – This project uses a reduced-order, strain based model to dynamically control a Soft Continuum Actuator (SCA) with bending and torsion. A closed-loop PD controller with feed forward is used to control the SCA.
  3. Zero-shot Sim-to-real Transfer of a Reinforcement Learning Policy – For this project, a custom soft continuum actuator simulation in Gazebo was created to train a Soft Actor-Critic Reinforcement Learning policy. A hardware replica of the simulation environment was built to evaluate the learned policy and develop techniques for effective zero-shot sim-to-real transfer. A 67% success rate of servoing the soft arm to view the target with the tip camera was achieved.

My previous work has included pre-touch sensing in occluded, cluttered environments.

Publications

  1. N. K. Uppalapati, B. T. Walt, A. Havens, A. Mahdian, G. Chowdhary, and G. Krishnan, “A Berry Picking Robot With A Hybrid Soft-Rigid Arm: Design and Task Space Control,” in Robotics: Science and Systems Foundation, 2020. (Link)(Link to pdf)
  2. S. K. Kamtikar, S. Marri, B. T. Walt, N. K. Uppalapati, G. Krishnan, and G. Chowdhary, “Visual Servoing for Pose Control of Soft Continuum Arm in a Structured Environment,” in IEEE Robotics and Automation Letters, 2022. DOI: 10.1109/LRA.2022.3155821 (IEEE Link)(Arxiv)
  3. B. T. Walt and G. Krishnan, “Grasp State Classification in Agricultural Manipulation,” in IEEE International Conference on Intelligent Robots and Systems, 2023. DOI: 10.1109/IROS55552.2023.10341881 (IEEE Link)
  4. K. Koe, S. Marri, B. Walt, S. Kamtikar, N. K. Uppalapati, G. Krishnan, G. Chowdhary, “Learning-Based Position and Orientation Control of a Hybrid Rigid-Soft Arm Manipulator,” in Journal of Mechanisms and Robotics, 2025. DOI: 10.1115/1.4067872
  5. K. Koe, P. K. Shah, B. Walt, J. Westphal, S. Marri, S. Kamtikar, J. S. Nam, N. K. Uppalapati, G. Krishnan, G. Chowdhary, “Precision Harvesting in Cluttered Environments: Integrating End Effector Design with Dual Camera Perception,” in IEEE International Conference on Robotics and Automation, 2025. (Accepted)
  6. H. Yang, M. Khosravi, B. Walt, G. Krishnan and S. Sarkar, “Zero-shot Sim-to-Real Transfer for Reinforcement Learning-based Visual Servoing of Soft Continuum Arms,” in Proceedings of the 7th Annual Learning for Dynamics & Control Conference, 2025. (Accepted)
  7. T. Wang, H. Chang, S. H. Kim, J. Guo, U. Akcal, B. Walt, D. Biskup, U. Halder, G. Krishnan, G. Chowdhary, M. Gazzola, P. G. Mehta, “A Neural Network-based Framework for Fast and Smooth Posture Reconstruction of a Soft Continuum Arm,” in IEEE International Conference on Robotics and Automation, 2025. (Accepted)

Teaching

Other

ME Qualification Exam Notes from May 2022

On Being a Non-Traditional Graduate Student