Learning Control

By combining dynamic systems and control theory with statistical and machine learning, we develop methods for automatic control design with limited a-priori knowledge, data-efficient reinforcement learning, and online adaptation of control systems. We believe that the combination of feedback and learning is essential to enable autonomous behavior in future (artifical) intelligent systems.


Event-based Estimation and Control

In almost all control systems today, data is sent and processed periodically. The periodic paradigm involves an inherent limitation: computation and data transmission happens at predetermined time instants, irrespective of the current state of the system or the information content of the data. Hence, hardware resources are used regardless of whether there is any need for control or estimation, which becomes prohibitive when communication and computational resources are limited such as in embedded or cyber-physical systems. We develop fundamentally new event-based sampling concepts for state estimation and control that achieve high-performance control while, at the same time, saving resources such as communication, computation, and energy.


Distributed and Networked Control

Modern communication technology allows intelligent systems to interconnect and share information with each other in order to increase collective knowledge or take collaborative action. We develop architectures and algorithms for distributed control and learning in multi-agent dynamic networks.


Bayesian State Estimation

Probability theory and Bayesian inference provide the theoretical underpinnings for filtering and state estimation algorithms used in almost all modern control systems. In our research, we have developed novel interpretations of commonly used Gaussian filters, which allow for improved filtering performance for many nonlinear problems, while maintaining the Gaussian filter's favorable computational complexity.


Applications to Robotics and Mechatronic Systems

Experiments with physical hardware such as robotic and mechatronic systems are an essential part of our research because they necessitate the consideration of all practical aspects of a complex system, they allow us to verify assumptions made in the theoretical derivations, and they reinforce and influence our theoretical research.

The videos below highlight some of our research. See 'Research Areas', 'Projects', and 'Publications' tabs for more information on the research in the Intelligent Control Systems group.

 

Bayesian optimization for controller learning

This video demonstrates the Automatic LQR Tuning algorithm for learning of multivariate feedback controllers from experiments. The algorithm leverages optimal control and Bayesian optimization for data-efficient learning. Relevant publication: \cite{marco_ICRA_2016}

 

Balancing Cube: A unique testbed for distributed control

The Balancing Cube is a dynamic sculpture that can balance autonomously on any one of its edges or corners. With six agents (the rotating arms) coordinating their actions to keep the structure in balance, the cube is a unique testbed for distributed state estimation and control. Relevant publications: \cite{trimpeCSM12,TrDAn11}

 

Student projects

We offer student projects in our research group both on Bachelor and Master level, as well as research internships at the PhD level.

We are always looking for excellent, motivated students to join our team. If you are interested in working with us, feel free to contact Sebastian Trimpe directly. Please include your CV and a short research statement relating to our work. Specific student projects and job openings are sometimes posted at the department website, but you may also contact us without any such opening.

 

University lecturing and tutorials

Lectures and tutorials held by Sebastian Trimpe:

  • Statistical Learning and Stochastic Control, graduate-level lecture, University of Stuttgart, Winter semester 2017/18 (lecturer with C. Ebenbauer and N. Radde)
  • Statistical Learning and Stochastic Control, graduate-level lecture, University of Stuttgart, Jan/Feb 2017 (guest lecturer)
  • Introduction to Distributed Event-based State Estimation, invited tutorial, IEEE MFI conference, Baden-Baden, Sep. 2016.
  • Recursive Estimation, gradulate-level lecture, ETH Zurich in Spring 2013 (responsible lecturer)

Public speaking

We are regularly invited to present our research to the general public. Some of our latest speaking engagements include:

  • Max Planck Institutes Tuebingen, Open House (Tag der offenen Tür), public lecture, July 2016.
  • Tech Open Air - An Interdisciplinary Technology Festival, Berlin, Germany, July 2015.
  • Several workshop for high school students and teachers on "Feedback control": for example, Boston, USA, Jul. 2016; Los Angeles, USA, Dec. 2014; Cape Town, South Africa, Aug. 2014.

 

Public exhibitions

Exhibitions of the Balancing Cube (with Raffaello D'Andrea):

  • European Control Conference, Zurich, Switzerland, Jul. 2013.
  • International Federation of Automatic Control (IFAC) World Congress, Milan, Italy, Aug. 2011.
  • Festival Della Scienza, Genoa, Italy, Oct. 2009.
  • Researchers‘ Night (Nacht der Forschung), Zurich, Switzerland, Sep. 2009.


The Balancing Cube during the 2011 World Congress of the International Federation of Automatic Control (IFAC).

 

Popular science articles

We have published about our research in popular science articles (in German):

  • S. Trimpe, Lernende Roboter, Jahrbuch der Max-Planck-Gesellschaft, May 2015.
  • S. Trimpe, Wenn es was zu sagen gibt, Bild der Wissenschaft, Sonderbeilage, S. 20-23, Nov. 2014. (This article won the 2014 Klaus Tschira Award for achievements in public understanding of science.)

For scientific publications, please see "Publications" tab.

 

Lab demos

We regularly present our research in live demonstrations to visitors from academia, media, and industry (e.g. Daimler, BMW, Bosch).

Our research is mainly funded by the Max Planck Society, the German Research Foundation (DFG), the Max Planck ETH Center for Learning Systems, and industry partners.

 

 

 

 

Collaborators

We are fortunate to be working with great colleagues and researchers at the Max Planck Institute (MPI) for Intelligent Systems, Tübingen, as well as from other international research institutions.

Collaborators at MPI Tübingen

External collaborators

 

Alumni

Former members of our group.

  • Anna Deichler (Master internship, 2017), now: TU Delft
  • Caroline Handel (Master thesis, 2017)
  • Andrea Bajcsy (Internship, 2016), now: PhD student at UC Berkeley
  • Harsoveet Singh (Master thesis, 2016)
  • Cédric de Crousaz (Master thesis, 2016), now: Associate Development Engineer at GoPro
  • Simon Ebner (Master thesis, 2016), now: CTO and co-founder Advertima
  • Alonso Marco Valle (Master thesis, 2015), now: PhD student with us
  • Andreas Dörr (Diploma thesis, 2015), now: PhD student with us and Bosch Renningen
  • Holger Kaden (Diploma thesis, 2014)

am Thumb sm trimpe2
Sebastian Trimpe (Group leader)
Research Group Leader
am Thumb sm dominik baumann
Dominik Baumann
Ph.D. Student
am Thumb sm andreas2
Andreas Doerr
Ph.D. Student
am Thumb sm whatsapp image 2017 09 20 at 10.40.06
Alonso Marco Valle
Ph.D. Student
am Thumb sm wuethrich medium
Manuel Wüthrich
Ph.D. Student

Collaborators

We are fortunate to be working with great colleagues and researchers at the Max Planck Institute (MPI) for Intelligent Systems, Tübingen, as well as from other international research institutions.

Collaborators at MPI Tübingen

External collaborators

 

Alumni

Former members of our group.

  • Anna Deichler (Master internship, 2017), now: TU Delft
  • Caroline Handel (Master thesis, 2017)
  • Andrea Bajcsy (Internship, 2016), now: PhD student at UC Berkeley
  • Harsoveet Singh (Master thesis, 2016)
  • Cédric de Crousaz (Master thesis, 2016), now: Associate Development Engineer at GoPro
  • Simon Ebner (Master thesis, 2016), now: CTO and co-founder Advertima
  • Alonso Marco Valle (Master thesis, 2015), now: PhD student with us
  • Andreas Dörr (Diploma thesis, 2015), now: PhD student with us and Bosch Renningen
  • Holger Kaden (Diploma thesis, 2014)

40 results

2017


Optimizing Long-term Predictions for Model-based Policy Search

Doerr, A., Daniel, C., Nguyen-Tuong, D., Marco, A., Schaal, S., Toussaint, M., Trimpe, S.

Proceedings of the 1st Annual Conference on Robot Learning, 1st Annual Conference on Robot Learning, November 2017 (conference) Accepted

[BibTex]

2017

[BibTex]


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On the Design of LQR Kernels for Efficient Controller Learning

Marco, A., Hennig, P., Schaal, S., Trimpe, S.

Proceedings of the 56th IEEE Conference on Decision and Control, December 2017 (conference) Accepted

Abstract
Finding optimal feedback controllers for nonlinear dynamic systems from data is hard. Recently, Bayesian optimization (BO) has been proposed as a powerful framework for direct controller tuning from experimental trials. For selecting the next query point and finding the global optimum, BO relies on a probabilistic description of the latent objective function, typically a Gaussian process (GP). As is shown herein, GPs with a common kernel choice can, however, lead to poor learning outcomes on standard quadratic control problems. For a first-order system, we construct two kernels that specifically leverage the structure of the well-known Linear Quadratic Regulator (LQR), yet retain the flexibility of Bayesian nonparametric learning. Simulations of uncertain linear and nonlinear systems demonstrate that the LQR kernels yield superior learning performance.

Project Page [BibTex]

Project Page [BibTex]


Distributed Event-Based State Estimation for Networked Systems: An LMI Approach

Muehlebach, M., Trimpe, S.

IEEE Transactions on Automatic Control, 2017 (article) In press

arXiv (extended version) DOI [BibTex]

arXiv (extended version) DOI [BibTex]


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Virtual vs. Real: Trading Off Simulations and Physical Experiments in Reinforcement Learning with Bayesian Optimization

Marco, A., Berkenkamp, F., Hennig, P., Schoellig, A. P., Krause, A., Schaal, S., Trimpe, S.

In Proceedings of the IEEE International Conference on Robotics and Automation (ICRA), pages: 1557-1563, IEEE International Conference on Robotics and Automation, May 2017 (inproceedings)

PDF arXiv DOI Project Page [BibTex]

PDF arXiv DOI Project Page [BibTex]


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Model-Based Policy Search for Automatic Tuning of Multivariate PID Controllers

Doerr, A., Nguyen-Tuong, D., Marco, A., Schaal, S., Trimpe, S.

In Proceedings of the IEEE International Conference on Robotics and Automation (ICRA), pages: 5295-5301, 2017 IEEE International Conference on Robotics and Automation, May 2017 (inproceedings)

PDF arXiv DOI [BibTex]

PDF arXiv DOI [BibTex]


Event-based State Estimation: An Emulation-based Approach

Trimpe, S.

IET Control Theory & Applications, 11(11):1684-1693, July 2017 (article)

Abstract
An event-based state estimation approach for reducing communication in a networked control system is proposed. Multiple distributed sensor agents observe a dynamic process and sporadically transmit their measurements to estimator agents over a shared bus network. Local event-triggering protocols ensure that data is transmitted only when necessary to meet a desired estimation accuracy. The event-based design is shown to emulate the performance of a centralised state observer design up to guaranteed bounds, but with reduced communication. The stability results for state estimation are extended to the distributed control system that results when the local estimates are used for feedback control. Results from numerical simulations and hardware experiments illustrate the effectiveness of the proposed approach in reducing network communication.

arXiv Supplementary material PDF DOI [BibTex]

arXiv Supplementary material PDF DOI [BibTex]

2016


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A New Perspective and Extension of the Gaussian Filter

Wüthrich, M., Trimpe, S., Garcia Cifuentes, C., Kappler, D., Schaal, S.

The International Journal of Robotics Research, 35(14):1731-1749, December 2016 (article)

Abstract
The Gaussian Filter (GF) is one of the most widely used filtering algorithms; instances are the Extended Kalman Filter, the Unscented Kalman Filter and the Divided Difference Filter. The GF represents the belief of the current state by a Gaussian distribution, whose mean is an affine function of the measurement. We show that this representation can be too restrictive to accurately capture the dependences in systems with nonlinear observation models, and we investigate how the GF can be generalized to alleviate this problem. To this end, we view the GF as the solution to a constrained optimization problem. From this new perspective, the GF is seen as a special case of a much broader class of filters, obtained by relaxing the constraint on the form of the approximate posterior. On this basis, we outline some conditions which potential generalizations have to satisfy in order to maintain the computational efficiency of the GF. We propose one concrete generalization which corresponds to the standard GF using a pseudo measurement instead of the actual measurement. Extending an existing GF implementation in this manner is trivial. Nevertheless, we show that this small change can have a major impact on the estimation accuracy.

PDF DOI Project Page [BibTex]

2016

PDF DOI Project Page [BibTex]


Predictive and Self Triggering for Event-based State Estimation

Trimpe, S.

In Proceedings of the 55th IEEE Conference on Decision and Control, pages: 3098-3105, Las Vegas, NV, USA, December 2016 (inproceedings)

arXiv PDF DOI Project Page [BibTex]

arXiv PDF DOI Project Page [BibTex]


Event-based Sampling for Reducing Communication Load in Realtime Human Motion Analysis by Wireless Inertial Sensor Networks

Laidig, D., Trimpe, S., Seel, T.

In Current Directions in Biomedical Engineering, 2(1), 2016 (inproceedings)

PDF DOI [BibTex]

PDF DOI [BibTex]


Communication Rate Analysis for Event-based State Estimation

(Best student paper finalist)

Ebner, S., Trimpe, S.

In Proceedings of the 13th International Workshop on Discrete Event Systems, May 2016 (inproceedings)

PDF DOI [BibTex]

PDF DOI [BibTex]


Supplemental material for ’Communication Rate Analysis for Event-based State Estimation’

Ebner, S., Trimpe, S.

Max Planck Institute for Intelligent Systems, January 2016 (techreport)

PDF [BibTex]


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Automatic LQR Tuning Based on Gaussian Process Global Optimization

Marco, A., Hennig, P., Bohg, J., Schaal, S., Trimpe, S.

In Proceedings of the IEEE International Conference on Robotics and Automation (ICRA), IEEE International Conference on Robotics and Automation, May 2016 (inproceedings)

Abstract
This paper proposes an automatic controller tuning framework based on linear optimal control combined with Bayesian optimization. With this framework, an initial set of controller gains is automatically improved according to a pre-defined performance objective evaluated from experimental data. The underlying Bayesian optimization algorithm is Entropy Search, which represents the latent objective as a Gaussian process and constructs an explicit belief over the location of the objective minimum. This is used to maximize the information gain from each experimental evaluation. Thus, this framework shall yield improved controllers with fewer evaluations compared to alternative approaches. A seven-degree- of-freedom robot arm balancing an inverted pole is used as the experimental demonstrator. Results of a two- and four- dimensional tuning problems highlight the method’s potential for automatic controller tuning on robotic platforms.

Video PDF DOI Project Page Project Page [BibTex]

Video PDF DOI Project Page Project Page [BibTex]


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Depth-based Object Tracking Using a Robust Gaussian Filter

Issac, J., Wüthrich, M., Garcia Cifuentes, C., Bohg, J., Trimpe, S., Schaal, S.

In Proceedings of the IEEE International Conference on Robotics and Automation (ICRA) 2016, IEEE, IEEE International Conference on Robotics and Automation, May 2016 (inproceedings)

Abstract
We consider the problem of model-based 3D- tracking of objects given dense depth images as input. Two difficulties preclude the application of a standard Gaussian filter to this problem. First of all, depth sensors are characterized by fat-tailed measurement noise. To address this issue, we show how a recently published robustification method for Gaussian filters can be applied to the problem at hand. Thereby, we avoid using heuristic outlier detection methods that simply reject measurements if they do not match the model. Secondly, the computational cost of the standard Gaussian filter is prohibitive due to the high-dimensional measurement, i.e. the depth image. To address this problem, we propose an approximation to reduce the computational complexity of the filter. In quantitative experiments on real data we show how our method clearly outperforms the standard Gaussian filter. Furthermore, we compare its performance to a particle-filter-based tracking method, and observe comparable computational efficiency and improved accuracy and smoothness of the estimates.

Video Bayesian Object Tracking Library Bayesian Filtering Framework Object Tracking Dataset link (url) DOI Project Page Project Page [BibTex]

Video Bayesian Object Tracking Library Bayesian Filtering Framework Object Tracking Dataset link (url) DOI Project Page Project Page [BibTex]


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Robust Gaussian Filtering using a Pseudo Measurement

Wüthrich, M., Garcia Cifuentes, C., Trimpe, S., Meier, F., Bohg, J., Issac, J., Schaal, S.

In Proceedings of the American Control Conference, Boston, MA, USA, July 2016 (inproceedings)

Abstract
Most widely-used state estimation algorithms, such as the Extended Kalman Filter and the Unscented Kalman Filter, belong to the family of Gaussian Filters (GF). Unfortunately, GFs fail if the measurement process is modelled by a fat-tailed distribution. This is a severe limitation, because thin-tailed measurement models, such as the analytically-convenient and therefore widely-used Gaussian distribution, are sensitive to outliers. In this paper, we show that mapping the measurements into a specific feature space enables any existing GF algorithm to work with fat-tailed measurement models. We find a feature function which is optimal under certain conditions. Simulation results show that the proposed method allows for robust filtering in both linear and nonlinear systems with measurements contaminated by fat-tailed noise.

Web link (url) DOI Project Page Project Page [BibTex]

2015


Distributed Event-based State Estimation

Trimpe, S.

Max Planck Institute for Intelligent Systems, November 2015 (techreport)

Abstract
An event-based state estimation approach for reducing communication in a networked control system is proposed. Multiple distributed sensor-actuator-agents observe a dynamic process and sporadically exchange their measurements and inputs over a bus network. Based on these data, each agent estimates the full state of the dynamic system, which may exhibit arbitrary inter-agent couplings. Local event-based protocols ensure that data is transmitted only when necessary to meet a desired estimation accuracy. This event-based scheme is shown to mimic a centralized Luenberger observer design up to guaranteed bounds, and stability is proven in the sense of bounded estimation errors for bounded disturbances. The stability result extends to the distributed control system that results when the local state estimates are used for distributed feedback control. Simulation results highlight the benefit of the event-based approach over classical periodic ones in reducing communication requirements.

arXiv [BibTex]

2015

arXiv [BibTex]


Policy Search for Imitation Learning

Doerr, A.

University of Stuttgart, January 2015 (thesis)

link (url) Project Page [BibTex]


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Gaussian Process Optimization for Self-Tuning Control

Marco, A.

Polytechnic University of Catalonia (BarcelonaTech), October 2015 (mastersthesis)

PDF Project Page Project Page [BibTex]

PDF Project Page Project Page [BibTex]


Adaptive and Learning Concepts in Hydraulic Force Control

Doerr, A.

University of Stuttgart, September 2015 (mastersthesis)

[BibTex]

[BibTex]


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Automatic LQR Tuning Based on Gaussian Process Optimization: Early Experimental Results

Marco, A., Hennig, P., Bohg, J., Schaal, S., Trimpe, S.

Machine Learning in Planning and Control of Robot Motion Workshop at the IEEE/RSJ International Conference on Intelligent Robots and Systems, September 2015 (conference)

Abstract
This paper proposes an automatic controller tuning framework based on linear optimal control combined with Bayesian optimization. With this framework, an initial set of controller gains is automatically improved according to a pre-defined performance objective evaluated from experimental data. The underlying Bayesian optimization algorithm is Entropy Search, which represents the latent objective as a Gaussian process and constructs an explicit belief over the location of the objective minimum. This is used to maximize the information gain from each experimental evaluation. Thus, this framework shall yield improved controllers with fewer evaluations compared to alternative approaches. A seven-degree-of-freedom robot arm balancing an inverted pole is used as the experimental demonstrator. Preliminary results of a low-dimensional tuning problem highlight the method’s potential for automatic controller tuning on robotic platforms.

PDF Project Page Project Page [BibTex]

PDF Project Page Project Page [BibTex]


Thumb md screen shot 2015 08 22 at 21.47.37
Direct Loss Minimization Inverse Optimal Control

Doerr, A., Ratliff, N., Bohg, J., Toussaint, M., Schaal, S.

In Proceedings of Robotics: Science and Systems, Rome, Italy, Robotics: Science and Systems XI, July 2015 (inproceedings)

Abstract
Inverse Optimal Control (IOC) has strongly impacted the systems engineering process, enabling automated planner tuning through straightforward and intuitive demonstration. The most successful and established applications, though, have been in lower dimensional problems such as navigation planning where exact optimal planning or control is feasible. In higher dimensional systems, such as humanoid robots, research has made substantial progress toward generalizing the ideas to model free or locally optimal settings, but these systems are complicated to the point where demonstration itself can be difficult. Typically, real-world applications are restricted to at best noisy or even partial or incomplete demonstrations that prove cumbersome in existing frameworks. This work derives a very flexible method of IOC based on a form of Structured Prediction known as Direct Loss Minimization. The resulting algorithm is essentially Policy Search on a reward function that rewards similarity to demonstrated behavior (using Covariance Matrix Adaptation (CMA) in our experiments). Our framework blurs the distinction between IOC, other forms of Imitation Learning, and Reinforcement Learning, enabling us to derive simple, versatile, and practical algorithms that blend imitation and reinforcement signals into a unified framework. Our experiments analyze various aspects of its performance and demonstrate its efficacy on conveying preferences for motion shaping and combined reach and grasp quality optimization.

PDF Video Project Page [BibTex]

PDF Video Project Page [BibTex]


Lernende Roboter

Trimpe, S.

In Jahrbuch der Max-Planck-Gesellschaft, Max Planck Society, May 2015, (popular science article in German) (inbook)

link (url) [BibTex]

link (url) [BibTex]


On the Choice of the Event Trigger in Event-based Estimation

Trimpe, S., Campi, M.

In Proceeding of the First International Conference on Event-based Control, Communication, and Signal Processing, June 2015 (inproceedings)

PDF DOI Project Page [BibTex]

PDF DOI Project Page [BibTex]


Guaranteed H2 Performance in Distributed Event-Based State Estimation

Muehlebach, M., Trimpe, S.

In Proceeding of the First International Conference on Event-based Control, Communication, and Signal Processing, June 2015 (inproceedings)

PDF DOI Project Page [BibTex]

PDF DOI Project Page [BibTex]


Event-based Estimation and Control for Remote Robot Operation with Reduced Communication

Trimpe, S., Buchli, J.

In Proceedings of the IEEE International Conference on Robotics and Automation, May 2015 (inproceedings)

Abstract
An event-based communication framework for remote operation of a robot via a bandwidth-limited network is proposed. The robot sends state and environment estimation data to the operator, and the operator transmits updated control commands or policies to the robot. Event-based communication protocols are designed to ensure that data is transmitted only when required: the robot sends new estimation data only if this yields a significant information gain at the operator, and the operator transmits an updated control policy only if this comes with a significant improvement in control performance. The developed framework is modular and can be used with any standard estimation and control algorithms. Simulation results of a robotic arm highlight its potential for an efficient use of limited communication resources, for example, in disaster response scenarios such as the DARPA Robotics Challenge.

PDF DOI Project Page [BibTex]

PDF DOI Project Page [BibTex]


LMI-Based Synthesis for Distributed Event-Based State Estimation

Muehlebach, M., Trimpe, S.

In Proceedings of the American Control Conference, July 2015 (inproceedings)

Abstract
This paper presents an LMI-based synthesis procedure for distributed event-based state estimation. Multiple agents observe and control a dynamic process by sporadically exchanging data over a broadcast network according to an event-based protocol. In previous work [1], the synthesis of event-based state estimators is based on a centralized design. In that case three different types of communication are required: event-based communication of measurements, periodic reset of all estimates to their joint average, and communication of inputs. The proposed synthesis problem eliminates the communication of inputs as well as the periodic resets (under favorable circumstances) by accounting explicitly for the distributed structure of the control system.

PDF DOI Project Page [BibTex]

PDF DOI Project Page [BibTex]


A New Perspective and Extension of the Gaussian Filter

Wüthrich, M., Trimpe, S., Kappler, D., Schaal, S.

In Robotics: Science and Systems, 2015 (inproceedings)

Abstract
The Gaussian Filter (GF) is one of the most widely used filtering algorithms; instances are the Extended Kalman Filter, the Unscented Kalman Filter and the Divided Difference Filter. GFs represent the belief of the current state by a Gaussian with the mean being an affine function of the measurement. We show that this representation can be too restrictive to accurately capture the dependencies in systems with nonlinear observation models, and we investigate how the GF can be generalized to alleviate this problem. To this end we view the GF from a variational-inference perspective, and analyze how restrictions on the form of the belief can be relaxed while maintaining simplicity and efficiency. This analysis provides a basis for generalizations of the GF. We propose one such generalization which coincides with a GF using a virtual measurement, obtained by applying a nonlinear function to the actual measurement. Numerical experiments show that the proposed Feature Gaussian Filter (FGF) can have a substantial performance advantage over the standard GF for systems with nonlinear observation models.

Web PDF Project Page [BibTex]

2014


Wenn es was zu sagen gibt

(Klaus Tschira Award 2014 in Computer Science)

Trimpe, S.

Bild der Wissenschaft, pages: 20-23, November 2014, (popular science article in German) (article)

PDF Project Page [BibTex]

2014

PDF Project Page [BibTex]


A Self-Tuning LQR Approach Demonstrated on an Inverted Pendulum

Trimpe, S., Millane, A., Doessegger, S., D’Andrea, R.

In Proceedings of the 19th IFAC World Congress, Cape Town, South Africa, 2014 (inproceedings)

PDF Supplementary material DOI Project Page [BibTex]

PDF Supplementary material DOI Project Page [BibTex]


A Limiting Property of the Matrix Exponential

Trimpe, S., D’Andrea, R.

IEEE Transactions on Automatic Control, 59(4):1105-1110, 2014 (article)

PDF DOI [BibTex]

PDF DOI [BibTex]


Event-Based State Estimation With Variance-Based Triggering

Trimpe, S., D’Andrea, R.

IEEE Transactions on Automatic Control, 59(12):3266-3281, 2014 (article)

PDF Supplementary material DOI Project Page [BibTex]

PDF Supplementary material DOI Project Page [BibTex]


Stability Analysis of Distributed Event-Based State Estimation

Trimpe, S.

In Proceedings of the 53rd IEEE Conference on Decision and Control, Los Angeles, CA, 2014 (inproceedings)

Abstract
An approach for distributed and event-based state estimation that was proposed in previous work [1] is analyzed and extended to practical networked systems in this paper. Multiple sensor-actuator-agents observe a dynamic process, sporadically exchange their measurements over a broadcast network according to an event-based protocol, and estimate the process state from the received data. The event-based approach was shown in [1] to mimic a centralized Luenberger observer up to guaranteed bounds, under the assumption of identical estimates on all agents. This assumption, however, is unrealistic (it is violated by a single packet drop or slight numerical inaccuracy) and removed herein. By means of a simulation example, it is shown that non-identical estimates can actually destabilize the overall system. To achieve stability, the event-based communication scheme is supplemented by periodic (but infrequent) exchange of the agentsâ?? estimates and reset to their joint average. When the local estimates are used for feedback control, the stability guarantee for the estimation problem extends to the event-based control system.

PDF Supplementary material DOI Project Page [BibTex]

PDF Supplementary material DOI Project Page [BibTex]

2012


Event-based State Estimation with Variance-Based Triggering

Trimpe, S., D’Andrea, R.

In Proceedings of the 51st IEEE Conference on Decision and Control, 2012 (inproceedings)

PDF Supplementary material DOI [BibTex]

2012

PDF Supplementary material DOI [BibTex]


Event-based State Estimation with Switching Static-gain Observers

Trimpe, S.

In Proceedings of the 3rd IFAC Workshop on Distributed Estimation and Control in Networked Systems, 2012 (inproceedings)

PDF DOI [BibTex]

PDF DOI [BibTex]


The Balancing Cube: A Dynamic Sculpture as Test Bed for Distributed Estimation and Control

Trimpe, S., D’Andrea, R.

IEEE Control Systems Magazine, 32(6):48-75, December 2012 (article)

DOI [BibTex]

DOI [BibTex]

2011


Reduced Communication State Estimation for Control of an Unstable Networked Control System

Trimpe, S., D’Andrea, R.

In Proceedings of the 50th IEEE Conference on Decision and Control and European Control Conference, 2011 (inproceedings)

PDF Supplementary material DOI [BibTex]

2011

PDF Supplementary material DOI [BibTex]


An Experimental Demonstration of a Distributed and Event-based State Estimation Algorithm

(Best Interactive Paper Award (top out of 450))

Trimpe, S., D’Andrea, R.

In Proceedings of the 18th IFAC World Congress, 2011 (inproceedings)

PDF DOI [BibTex]

PDF DOI [BibTex]

2010


Accelerometer-based Tilt Estimation of a Rigid Body with only Rotational Degrees of Freedom

Trimpe, S., D’Andrea, R.

In Proceedings of the IEEE International Conference on Robotics and Automation, 2010 (inproceedings)

PDF DOI [BibTex]

2010

PDF DOI [BibTex]

2009


A Limiting Property of the Matrix Exponential with Application to Multi-loop Control

Trimpe, S., D’Andrea, R.

In Proceedings of the Joint 48th IEEE Conference on Decision (CDC) and Control and 28th Chinese Control Conference, 2009 (inproceedings)

PDF DOI [BibTex]

2009

PDF DOI [BibTex]

2007


Less Conservative Polytopic LPV Models for Charge Control by Combining Parameter Set Mapping and Set Intersection

Kwiatkowski, A., Trimpe, S., Werner, H.

In Proceedings of the 46th IEEE Conference on Decision and Control, 2007 (inproceedings)

DOI [BibTex]

2007

DOI [BibTex]

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Automatic Design of Feedback Controllers

Autonomous systems such as humanoid robots are characterized by a multitude of feedback control loops operating at different hierarchical levels and time-scales. Designing and tuning these controllers typically requires significant manual modeling and design effort and exhaustive experimental testing. For managing the ever greater c...

Sebastian Trimpe Alonso Marco Valle Philipp Hennig Jeannette Bohg Stefan Schaal


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Gaussian Filtering as Variational Inference

Decision making requires knowledge of some variables of interest. In the vast majority of real-world problems, these variables are latent, i.e. they cannot be observed directly and must be inferred from available measurements. To maintain an up-to-date distribution over the latent variables, past beliefs have to ...

Manuel Wüthrich Sebastian Trimpe Cristina Garcia Cifuentes Jan Issac Daniel Kappler Franzi Meier Jeannette Bohg Stefan Schaal


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Networked Control and Communication

Future intelligent systems such as autonomous robots, self-driving cars, or manufacturing systems will be connected over communication networks. Facilitated by the network, the individual agents can coordinate their actions and thus achieve functionality exceeding the individual unit (for example, driving in formation or collaborati...

Sebastian Trimpe Simon Ebner


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Event-based Wireless Control of Cyber-physical Systems

Wireless communication and embedded computation are key enabling technologies for future autonomous systems. Embedded devices allow for gathering and processing data in remote and distributed locations, while wireless multi-hop networks offer unprecedented flexibility in sharing data between these devices, for example, to increase c...

Sebastian Trimpe Dominik Baumann Harsoveet Singh