Markus Ryll

E-Mail: Markus.Ryll


Picture of Ryll, Markus

Markus Ryll

Position: PhD Student  Unit: Alumni Bülthoff

Research Group: Autonomous Robotics and Human Machine Systems

Supervisor: Paolo Robuffo Giordano


I am a Ph.D. student with a background in Medical Engineering and Mechatronics. In the group Autonomous Robotics and Human Machine Systems group of Dr. Antonio Franchi (Max Planck Institute for Biological Cybernetics) I am working on the further development of quadcopter control.

Quadcopter with tilt rotor arms



Currently I am interested in:

  • Micro aerial vehicles (MAV)
  • Advances MAV designs
  • Quadcopter flight behavior
  • Quadcopter control
  • Aerial grasping
  • Mechanical Engineering
  • Teleoperation
  • Software Engineering



Actual I am working on the design of a new Micro aerial vehicle. For more information check my projects.



Micro aerial vehicles (MAVs) are an increasingly important research field. On the one hand, the idea of using MAVs in cluttered indoor environments and for rescue and surveillance tasks is becoming increasingly popular. On the other hand, the development of new MAV concepts and the related control issues represent scientific challenges. For instance: what is necessary to control a micro aerial vehicle in an unknown and cluttered environment? What are the requirements for such a MAV? What kind of sensor inputs is necessary and what kind of autonomy is needed? Shall the MAV be completely autonomous or under the supervision of a human operator as in teleoperation scenarios?



Custom quadrotor helicopters have the drawback of being Tilt rotor armunderactuated: they only possess four independent control inputs w.r.t. their 6-dof pose in space. A rotation in roll or pitch causes a Cartesian acceleration into the same direction. As a consequence, it can be proven that quadrotors are only able to independently act on their Cartesian position and yaw angle, this means 4 dofs. This imposes some limitations. For example, a sensor or gripper attached to the robot cannot be arbitrarily oriented during flight nor the quadrotor can hover in place with any body orientation. In the Human-Robot-Interaction group, we are developing a new kind of MAV. Based on the concept of a quadrotor helicopter with four propellers, we extend this design to allow the four propellers to tilt about their axes w.r.t. the quadrotor body. This gives us full control over the 6 dofs of the quadrotor body, and better chances to interact with and manipulate the environment.



Starting from first principles, we aim at deriving a realistic dynamical model of our envisage quadrotor and at devising advanced nonlinear controllers which can exploit the additional actuated degrees of freedom. Inertial and aerodynamics effects will also be considered in order to improve the realism of the model. Besides providing a matlab implementation, we will also port the quadrotor model into our own real-time multi-robot simulation environment with a physically realistic engine.

In a future step, we plan to build a prototype of this new quadrotor concept in order to test and validate in real conditions both the models and controllers obtained during the simulation stage. To this end, we will make use of our two Flying-Arenas equipped Vicon tracking systems for obtaining an external ground truth.


Initial results

We developed a dynamic model of the quadrotor with actuated propellers and devised a nonlinear controller based on dynamic feedback linearization. Simulation results confirm the validity of our methods.


Initial conclusion

The Human-Robot-Interaction group develops a new kind of quadrotor helicopter with tilt rotors to control all 6 Cartesian space dofs. This MAV will be able to interact with and manipulate the environment.




2010 - now Ph.D. Student
supervised by Dr. Paolo Robuffo Giordano
Department Human Perception, Cognition and Action (Dept. Head: Heinrich H. Buelthoff), Max Planck Institute for Biological Cybernetics, Tübingen, Germany


2008 – 2010 Master Student

Medical Engineering - University of Applied Science Ulm (Grade 1.2)


2005 – 2008 Diploma Student

Mechatronics - Baden-Württemberg Cooperative State University, Karlsruhe (Grade 1.5)


1995 – 2004 High School Student

Solitude-Gymnasium, Stuttgart


Work Experience


2011 – now Teaching Activity, Stuttgart

Lecturer for Applied Mechanics at Baden-Württemberg Cooperative State University, Stuttgart

2009 – 2010 Karolinska Institute, Stockholm

Development and apply of Fourier and single particle refinement methods in the determination of protein structures from poorly ordered two-dimensional protein crystals at Department of Biosciences and Nutrition.


2005 – 2008 Forschungszentrum Karlsruhe GmbH

Development of mechanical constructions, electronics and software (computer vision) for the autonomic service robot KASPER at the Institute of Applied Computer Science, Karlsruhe


References per page: Year: Medium:

Show abstracts

Articles (3):

Ryll M, Bülthoff HH and Robuffo Giordano P (February-2015) A Novel Overactuated Quadrotor Unmanned Aerial Vehicle: Modeling, Control, and Experimental Validation IEEE Transactions on Control Systems Technology 23(2) 540-556.
Franchi A, Masone C, Grabe V, Ryll M, Bülthoff HH and Robuffo Giordano P (October-2012) Modeling and Control of UAV Bearing-Formations with Bilateral High-Level Steering International Journal of Robotics Research 31(12) 1504-1525.
Franchi A, Secchi C, Ryll M, Bülthoff HH and Robuffo Giordano P (September-2012) Shared Control: Balancing Autonomy and Human Assistance with a Group of Quadrotor UAVs IEEE Robotics & Automation Magazine 19(3) 57-68.

Conference papers (5):

Rajappa S, Ryll M, Bülthoff HH and Franchi A (May-2015) Modeling, Control and Design Optimization for a Fully-actuated Hexarotor Aerial Vehicle with Tilted Propellers, IEEE International Conference on Robotics and Automation (ICRA 2015), IEEE, Piscataway, NJ, USA, 4006-4013.
Gioioso G, Ryll M, Prattichizzo D, Bülthoff HH and Franchi A (June-2014) Turning a near-hovering controlled quadrotor into a 3D force effector, IEEE International Conference on Robotics and Automation (ICRA 2014), IEEE, Piscataway, NJ, USA, 6278-6284.
Spica R, Robuffo Giordano P, Ryll M, Bülthoff HH and Franchi A (November-2013) An Open-Source Hardware/Software Architecture for Quadrotor UAVs, 2nd Workshop on Research, Education and Development of Unmanned Aerial Systems (RED-UAS 2013), International Federation of Automatic Control, New York, NY, USA, IFAC Proceedings Volumes, 46(30), 198-205.
Ryll M, Bülthoff HH and Robuffo Giordano P (May-2013) First Flight Tests for a Quadrotor UAV with Tilting Propellers, IEEE International Conference on Robotics and Automation (ICRA 2013), IEEE, Piscataway, NJ, USA, 295-302.
Ryll M, Bülthoff HH and Robuffo Giordano P (May-2012) Modeling and Control of a Quadrotor UAV with Tilting Propellers, IEEE International Conference on Robotics and Automation (ICRA 2012), IEEE, Piscataway, NJ, USA, 4606-4613.

Posters (2):

Ryll M, Bülthoff HH and Robuffo Giordano P (September-25-2013): Overactuation in UAVs for Enhanced Aerial Manipulation: A Novel Quadrotor Concept with Tilting, 6th International Workshop on Human-Friendly Robotics (HFR 2013), Roma, Italy.
Ryll M (October-2010): Proteins: Single particle reconstruction based on 2d crystals, 11th Conference of Junior Neuroscientists of Tübingen (NeNa 2010), Heiligkreuztal, Germany.

Theses (1):

Ryll M: A novel overactuated quadrotor UAV, Universität Stuttgart, (July-27-2015). PhD thesis

Talks (1):

Ryll M (September-6-2012) Invited Lecture: Overactuation in UAVs – Modeling and Control of a Quadrotor with Tilting Propellers, DGR-Tage 2012 (Deutsche Gesellschaft für Robotik): Technische Universität Berlin, Berlin, Germany.

Export as:
BibTeX, XML, Pubman, Edoc, RTF
Last updated: Tuesday, 18.11.2014