User-Adaptive Control with Minimum-Jerk Planning

We developed a novel control architecture for robotic leg prostheses that adapts online at each step to provide biological accurate function. The movement of the prosthesis during swing phase adapts online to the specific user gait pattern using minimum-jerk principle. Minimum-jerk provides an optimal way to program smooth movements, allowing amputees to obtain physiological gait symmetry at variable cadences, and potentially handling unexpected perturbations such as tripping. This controller was first tested on the Vanderbilt leg–a state of the art powered ankle and knee prosthesis developed by Dr. Michael Goldfarb at Vanderbilt University. Read More.

Adaptive Oscillator Control

Adaptive Oscillators are a mathematical tool that can learn any periodic signal and provide a smooth estimate of its phase and offset. By using this innovative tool, we moved from a time-based to a phase-based control system for powered exoskeletons that is more robust to natural movement variability. Experiments show that this control approach can effectively provide assistance by reducing the user effort during walking. Read More.