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Institute Talks

Control Systems for a Surgical Robot on the Space Station

IS Colloquium
  • 23 October 2018 • 16:30 17:30
  • Chris Macnab
  • MPI-IS Stuttgart, Heisenbergstr. 3, Room 2P4

As part of a proposed design for a surgical robot on the space station, my research group has been asked to look at controls that can provide literally surgical precision. Due to excessive time delay, we envision a system with a local model being controlled by a surgeon while the remote system on the space station follows along in a safe manner. Two of the major design considerations that come into play for the low-level feedback loops on the remote side are 1) the harmonic drives in a robot will cause excessive vibrations in a micro-gravity environment unless active damping strategies are employed and 2) when interacting with a human tissue environment the robot must apply smooth control signals that result in precise positions and forces. Thus, we envision intelligent strategies that utilize nonlinear, adaptive, neural-network, and/or fuzzy control theory as the most suitable. However, space agencies, or their engineering sub-contractors, typically provide gain and phase margin characteristics as requirements to the engineers involved in a control system design, which are normally associated with PID or other traditional linear control schemes. We are currently endeavouring to create intelligent controls that have guaranteed gain and phase margins using the Cerebellar Model Articulation Controller.

Organizers: Katherine Kuchenbecker

Artificial haptic intelligence for human-machine systems

IS Colloquium
  • 24 October 2018 • 11:00 12:00
  • Veronica J. Santos
  • 5H7 at MPI-IS in Stuttgart

The functionality of artificial manipulators could be enhanced by artificial “haptic intelligence” that enables the identification of object features via touch for semi-autonomous decision-making and/or display to a human operator. This could be especially useful when complementary sensory modalities, such as vision, are unavailable. I will highlight past and present work to enhance the functionality of artificial hands in human-machine systems. I will describe efforts to develop multimodal tactile sensor skins, and to teach robots how to haptically perceive salient geometric features such as edges and fingertip-sized bumps and pits using machine learning techniques. I will describe the use of reinforcement learning to teach robots goal-based policies for a functional contour-following task: the closure of a ziplock bag. Our Contextual Multi-Armed Bandits approach tightly couples robot actions to the tactile and proprioceptive consequences of the actions, and selects future actions based on prior experiences, the current context, and a functional task goal. Finally, I will describe current efforts to develop real-time capabilities for the perception of tactile directionality, and to develop models for haptically locating objects buried in granular media. Real-time haptic perception and decision-making capabilities could be used to advance semi-autonomous robot systems and reduce the cognitive burden on human teleoperators of devices ranging from wheelchair-mounted robots to explosive ordnance disposal robots.

Organizers: Katherine Kuchenbecker


IS Colloquium
  • 28 January 2019 • 3pm 4pm
  • Florian Marquardt

Organizers: Matthias Bauer

  • Ravi Haksar
  • MPI-IS Stuttgart, seminar room 2P4

What do forest fires, disease outbreaks, robot swarms, and social networks have in common? How can we develop a common set of tools for these applications? In this talk, I will first introduce a modeling framework that describes large-scale phenomena and which is based on the idea of "local interactions." I will then describe my work on creating estimation and control methods for a single agent and for a cooperative team of autonomous agents. In particular, these algorithms are scalable as the solution does not change if the number of agents or environment size changes. Forest fires and the 2013 Ebola outbreak in West Africa are presented as examples.

Organizers: Sebastian Trimpe

  • Charlotte Le Mouel
  • 2P4, Heisenbergstr. 3, 70188 Stuttgart

Theories of motor control in neuroscience usually focus on the role of the nervous system in the coordination of movement. However, the literature in sports science as well as in embodied robotics suggests that improvements in motor performance can be achieved through an improvement of the body mechanical properties themselves, rather than only the control. I therefore developed the thesis that efficient motor coordination in animals and humans relies on the adjustment of the body mechanical properties to the task at hand, by the postural system.

Organizers: Charlotte Le Mouel Alexander Sproewitz

  • Mario Herger
  • Kupferbau Universität Tübingen, Hörsaal 22

Über 1.000 selbstfahrende Testfahrzeuge von insgesamt 57 Unternehmen fahren im Silicon Valley bereits herum, und nun steht die Google-Schwester Waymo davor, 82.000 Robotertaxis auf die Straßen zu bringen. Und das nicht irgendwann, sondern noch dieses Jahr. Währenddessen rüstet sich Tesla mit seinem vollelektrischen Model 3 für einen Frontalangriff auf die deutschen Hersteller. In den USA sind die Verkaufszahlen deutscher Mittelklassewagen im Vergleich zum Vorjahr um 29 Prozent eingebrochen.

Still, In Motion

  • 12 October 2018 • 11:00 12:00
  • Michael Cohen

In this talk, I will take an autobiographical approach to explain both where we have come from in computer graphics from the early days of rendering, and to point towards where we are going in this new world of smartphones and social media. We are at a point in history where the abilities to express oneself with media is unparalleled. The ubiquity and power of mobile devices coupled with new algorithmic paradigms is opening new expressive possibilities weekly. At the same time, these new creative media (composite imagery, augmented imagery, short form video, 3D photos) also offer unprecedented abilities to move freely between what is real and unreal. I will focus on the spaces in between images and video, and in between objective and subjective reality. Finally, I will close with some lessons learned along the way.

  • Mariacarla Memeo
  • MPI-IS Stuttgart, Heisenbergstr. 3, Room 2P4

The increasing availability of on-line resources and the widespread practice of storing data over the internet arise the problem of their accessibility for visually impaired people. A translation from the visual domain to the available modalities is therefore necessary to study if this access is somewhat possible. However, the translation of information from vision to touch is necessarily impaired due to the superiority of vision during the acquisition process. Yet, compromises exist as visual information can be simplified, sketched. A picture can become a map. An object can become a geometrical shape. Under some circumstances, and with a reasonable loss of generality, touch can substitute vision. In particular, when touch substitutes vision, data can be differentiated by adding a further dimension to the tactile feedback, i.e. extending tactile feedback to three dimensions instead of two. This mode has been chosen because it mimics our natural way of following object profiles with fingers. Specifically, regardless if a hand lying on an object is moving or not, our tactile and proprioceptive systems are both stimulated and tell us something about which object we are manipulating, what can be its shape and size. The goal of this talk is to describe how to exploit tactile stimulation to render digital information non visually, so that cognitive maps associated with this information can be efficiently elicited from visually impaired persons. In particular, the focus is to deliver geometrical information in a learning scenario. Moreover, a completely blind interaction with virtual environment in a learning scenario is something little investigated because visually impaired subjects are often passive agents of exercises with fixed environment constraints. For this reason, during the talk I will provide my personal answer to the question: can visually impaired people manipulate dynamic virtual content through touch? This process is much more challenging than only exploring and learning a virtual content, but at the same time it leads to a more conscious and dynamic creation of the spatial understanding of an environment during tactile exploration.

Organizers: Katherine Kuchenbecker

  • Gokhan Serhat
  • MPI-IS Stuttgart, Heisenbergstr. 3, Room 2P4

Continuum structures need to be designed for optimal vibrational characteristics in various fields. Recent developments in the finite element analysis (FEA) and numerical optimization methods allow creating more accurate computational models, which favors designing superior systems and reduces the need for experimentation. In this talk, I will present my work on FEA-based optimization of thin shell structures for improved dynamic properties where the focus will be on laminated composites. I will initially explain multi-objective optimization strategies for enhancing load-carrying and vibrational performance of plate structures. The talk will continue with the design of curved panels for optimal free and forced dynamic responses. After that, I will present advanced methods that I developed for modeling and optimization of variable-stiffness structures. Finally, I will outline the state-of-the-art techniques regarding numerical simulation of the finger in contact with surfaces and propose potential research directions.

Organizers: Katherine Kuchenbecker

Soft Feel by Soft Robotic Hand: New way of robotic sensing

IS Colloquium
  • 04 October 2018 • 13:30 - 04 September 2018 • 14:30
  • Prof. Koh Hosoda
  • MPI-IS Stuttgart, Werner-Köster lecture hall

This lecture will show some interesting examples how soft body/skin will change your idea of robotic sensing. Soft Robotics does not only discuss about compliance and safety; soft structure will change the way to categorize objects by dynamic exploration and enables the robot to learn sense of slip. Soft Robotics will entirely change your idea how to design sensing and open up a new way to understand human sensing.

Organizers: Ardian Jusufi

  • Prof. Peter Pott
  • MPI-IS Stuttgart, Heisenbergstr. 3, Room 2P4

The FLEXMIN haptic robotic system is a single-port tele-manipulator for robotic surgery in the small pelvis. Using a transanal approach it allows bi-manual tasks such as grasping, monopolar cutting, and suturing with a footprint of Ø 160 x 240 mm³. Forces up to 5 N in all direction can be applied easily. In addition to provide low latency and highly dynamic control over its movements, high-fidelity haptic feedback was realised using built-in force sensors, lightweight and friction-optimized kinematics as well as dedicated parallel kinematics input devices. After a brief description of the system and some of its key aspects, first evaluation results will be presented. In the second half of the talk the Institute of Medical Device Technology will be presented. The institute was founded in July 2017 and has ever since started a number of projects in the field of biomedical actuation, medical systems and robotics and advanced light microscopy. To illustrate this a few snapshots of bits and pieces will be presented that are condensation nuclei for the future.

Organizers: Katherine Kuchenbecker

Private Federated Learning

  • 01 October 2018 • 10:00 10:45
  • Mona Buisson-Fenet
  • MPI-IS Stuttgart, seminar room 2P4

With the expanding collection of data, organisations are becoming more and more aware of the potential gain of combining their data. Analytic and predictive tasks, such as classification, perform more accurately if more features or more data records are available, which is why data providers have an interest in joining their datasets and learning from the obtained database. However, this rising interest for federated learning also comes with an increasing concern about security and privacy, both from the consumers whose data is used, and from the data providers who are liable for protecting it. Securely learning a classifier over joint datasets is a first milestone for private multi-party machine learning, and though some literature exists on that topic, systems providing a better security-utility trade-off and more theoretical guarantees are still needed. An ongoing issue is how to deal with the loss gradients, which often need to be revealed in the clear during training. We show that this constitutes an information leak, and present an alternative optimisation strategy that provides additional security guarantees while limiting the decrease in performance of the obtained classifier. Combining an encryption-based and a noise-based approach, the proposed method enables several parties to jointly train a binary classifier over vertically partitioned datasets while keeping their data private.

Organizers: Sebastian Trimpe

  • Dr. Aude Bolopion and Dr. Mich
  • 2P4

This talk presents an overview of recent activities of FEMTO-ST institute in the field of micro-nanomanipulation fo both micro nano assembly and biomedical applications. Microrobotic systems are currently limited by the number of degree of freedom addressed and also are very limited by their throughput. Two ways can be considered to improve both the velocity and the degrees of freedom: non-contact manipulation and dexterous micromanipulation. Indeed in both ways movement including rotation and translation are done locally and are only limited by the micro-nano-objects inertia which is very low. It consequently enable to generate 6DOF and to induce high dynamics. The talk presents recent works which have shown that controlled trajectories in non contact manipulation enable to manipulate micro-objects in high speed. Dexterous manipulation on a 4 fingers microtweezers have been also experimented and show that in-hand micromanipulations are possible in micro-nanoscale based on original finger trajectory planning. These two approaches have been applied to perform micro-nano-assemby and biomedical operations