Maziar A. Sharbafi


Dr. Maziar Sharbafi is a senior IEEE member with more than 80 international peer reviewed publications. He received his B.Sc. degree from the Sharif University of Technology, Tehran, Iran, in 2003, and M.Sc. and PhD degrees from the University of Tehran, Tehran, Iran, in 2006 and 2013, all in control engineering. He earned his second PhD in Biomechanics in 2017 from Technical University of Darmstadt. Previously, he was an Assistant Professor of Electrical and Computer Engineering Department, University of Tehran, and a Guest Researcher with the Lauflabor Locomotion Laboratory, TU Darmstadt. He is now the leader of Locomotion Control Assistance group at TU Darmstadt  and the principal investigator in EPA (electric-pneumatic actuator) project series (EPA and EPA-2) granted by German Research Foundation (DFG).


His research interests include bioinspired locomotion control based on conceptual and analytic approaches, postural stability, and the application of dynamical systems and nonlinear control to hybrid systems such as legged robots and exoskeletons. He was involved in conducting research and supervising students in European and German funded projects (e.g, Balance and BioBiped project).


He is now the PI of the EPA-2 project and the WP leader in WhiteBox project. He is also the scientific coordinator in the LokoAssist graduate school. For more details about the current and past projects see Projects.





Locomotion Control Assistance Group

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 includes:


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.


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.




Replicating machines: In the growing market of robots replicating human behavior, bioinspired robots such as “Cassie” from Agility Robotics with simplified design and control could become the first commercial legged service robot. Using force control and compliant design are some bioinspired features of Cassie that is now used for package delivery. It is a successful instance of replicating human activities with a bioinspired legged robot. These robots could provide a breakthrough in logistics, health care, and automatization of different industries in the near future. I followed this bioinspired concept in designing and controlling robots, such as  EPA-hopper and EPA-Walker.


Compared to biological muscles, current technical actuators are limited in their performance and versatility to realize human-like locomotion. For resolving this problem we need to better understand biological legged locomotion which can be described in a three-level structure: 1) generation of the different locomotor subfunctions (LSF), namely stance, swing and balance, 2) composition of LSFs for versatile legged locomotion and 3) LSF adaptation for various locomotion tasks and conditions.

In order to overcome the actuator limitations for locomotion, I recently introduced the hybrid EPA actuator as a combination of electric and pneumatic actuators. The EPA design provides direct access to the control and morphological properties. We recently demonstrated that with the EPA, the actuator limitations could be clearly reduced for stance LSF in vertical hopping. In 2022, the EPA-Walker robot with this novel hybrid actuation system is developed.

Exoskeleton and Exosuits

Supporting machines: I devoted the second part of my research to utilizing the obtained knowledge where humans require support in their daily activities. In this regard, I am using the design and manufacturing of legged robots as a reverse engineering method to understand human locomotion and to investigate the developed hypotheses of motor control and morphological computation found in human movement. Consequently, gait assistance, training, and therapy can be valuable applications of biomechanics and motor control in real life. I believe wearable robots such as exoskeletons and exosuits  ̵ ­usable by both healthy and impaired (or elderly) people ̵   will significantly improve the quality of life in the near future. Thus, choosing this research topic will target the market while serving society, regarding service jobs, sport, ergonomics, and medical care and rehabilitation. 

I developed passive and active exosuits (BATEX) and  I also introduced the bioinspired force-based controller (FMC) and implemented it on an Odyssey ankle prosthesis (from spring-active) and LOPES II exoskeleton (at the University of Twente).


Design and control: In addition to exoskeletons and exosuits, I also researched prosthetics. 


Neurormechanical control: I developed the FMCA  (force modulated compliant ankle) controller and applied to  prosthesis. This neuromechanical controller is applied to a prosthesis. Together with Mr. Naseri, Dr. Grimmer and Prof. Seyfarth, we wrote a book chapter on this topic titled Neural control in prostheses and exoskeletons


Prosthsis design: We designed and developed a passive hybrid prosthesis H2AP, which is patented by US patent office. We introduced a methodological design to passively support human pushoff power with a combination of spring and dampers which contributed at different instances of the gait. Details acan be found in an article published in 2022.

Selected Talks