Locomotion Control Assistance
Overview
This research line was established in 2021 in the Biomechanics group, sport science institute, and cognitive science center at TU Darmstadt. With the growing application of artificial intelligence and robotics, we aim to employ intelligent robots to make human life safer, easier, and more productive, e.g., with wearable assistive robots supporting the independent living of older adults. Based on the existing multi-disciplinary research expertise in control engineering, robotics, and biomechanics leading to new bioinspired assistive devices, legged locomotion, and actuation, we focus on human-centered robotics. The central part of the research in this group focuses on the design and control of locomotor systems and their applications for assistive devices. We aim to improve body and brain intelligence in artificial locomotor systems, from robots to exoskeletons. The current research is based on a new concept of brain and body (B+B) intelligence which includes:
1- Intelligent control: We use bioinspired model-based control methods. Some of the developed novel concepts e.g., FMC and concerted control (see below)
2- Smart body design: Bioinspired mechanical designs for robots and assistive devices e.g., EPA actuation (see below or description of EPA project here.
3- Brain in the loop: This is a new concept in which we use the brain signals to identify the human perception of assistance and apply it later for control adaptation.
Core Concepts
Control
Control: Biological legged locomotor systems are too complicated to be replicated in robots. We use different levels of modeling, biomechanical and neurological knowledge to simplify this complex problem. Template-based modeling and reflex control are some of the key toolboxes in our robot control. I introduced new concepts such as Force modulated compliance (FMC), which successfully predicted human locomotion control, and applied it to robots and assistive devices. An extension of this concept to synchronize different locomotor subfunctions to present the concerted control concept is under investigation.
Mechanical Design
Control embodiment in the machines' mechanics is this section's primary mission. In that respect, the body is not a passive system to be controlled but a pivotal contributor to facilitating control and increasing movement abilities. Morphological and actuation designs are the two main pillars of this research. Hybrid actuation with the electric-pneumatic actuator (EPA) and combinations of mono- and biarticular arrangements are central tools to implement bioinspired designs on assistive devices and to investigate biomechanical hypotheses in legged robots.
Brain in the Loop
We recently started researching applying BCI to adapt gait assistance in a biocompatible way. The idea is to use passive BCI to detect human evaluation of assistance. This concept is under development within the LokoAssist project in collaboration with Prof. Rinderkenecht and Vogt from TU Darmstadt. We also collaborate with Profs Zander (TU Brandenburg) & Chen (SJU) on the concept of Brain-in-the-loop optimization (BILO) for the personalization of assistive devices.
