Portfolio

Multi-Robot Coordinated Planning and Control

Multi-robot motion planning and control has been investigated for decades and is still an active research area due to the growing demand for both performance optimality and safety assurance. We developed learning-based methods and distributed model predictive control (DMPC) methods: 1) a gradient-based algorithm that leverages the alternating direction method of multipliers (ADMM) to decompose the team-level trajectory optimization into subproblems solved by individual robots. The algorithm also incorporates a discrete-time control barrier functions (CBF) as safety constraints to provide formal guarantee of collision avoidance; and 2) a sampling-based method that formulates multi-robot optimal control as probabilistic inference over graphical models and leverages belief propagation to achieve inference via distributed computation. We developed a distributed sampling-based model predictive control (MPC) algorithm based on the proposed framework, which obtains optimal controls via variational inference (VI).

NRI: FND: The Robotic Rehab Gym: Specialized Co-Robot Trainers Working with Multiple Human Trainees for Optimal Learning Outcomes, sponsored by NSF, 2020-2025

Overview: A robotic rehabilitation gym is defined as multiple patients training with multiple robots or passive sensorized devices in a group setting. Recent work with such gyms has shown positive rehabilitation outcomes; furthermore, such gyms allow a single therapist to supervise more than one patient, increasing cost-effectiveness. To allow more effective multipatient supervision in future robotic rehabilitation gyms, this project investigates automated systems that can dynamically assign patients to different robots within a session in order to optimize group rehabilitation outcome.

Adaptive Shared Autonomy for Assistive Robotic Manipulation

Overview: Shared autonomy promotes collaboration between humans and robots by integrating human input with autonomous control, allowing humans to perform tasks without the need for precise manual control. A primary problem in shared autonomy is how to determine the optimal balance of control between the user and robot. This problem is further complicated by the variability in human proficiency and preference when performing manipulation tasks. Addressing this issue requires systems to infer human skill levels, enabling dynamic adjustments to the level of assistance. Such adaptability ensures that assistance is neither overly intrusive for experienced users nor insufficient for novices. To address this challenge, this project investigates human-centric shared autonomy approaches that offers adaptive and personalized level of assistance.