The Mini-Robot Khepera as a Foraging Animate: Synthesis and Analysis of Behaviour

Löffler A, Klahold J, Rückert U. The Mini-Robot Khepera as a Foraging Animate: Synthesis and Analysis of Behaviour. In: Rückert U, Sitte J, Witkowski U, eds. Proceedings of the 5th International Heinz Nixdorf Symposium: Autonomous Minirobots for Research and Edutainment (AMiRE01). Vol 97. Paderborn, Germany: Heinz Nixdorf Institut, Universität Paderborn; 2001: 93-130.The work presented in this paper deals with the development of a methodology for resource-efficient behaviour synthesis on autonomous systems. In this context, a definition of a maximal problem with respect to the resources of a given system is introduced. It is elucidated by means of an exemplary implementation of the solution to such a problem using the mini-robot Khepera as the experimental platform. The described task consists of exploring an unknown and dynamically changing environment, collecting and transporting objects, which are associated with light-sources, and navigating to a home-base. The critical point is represented by the accumulated positioning errors in odometrical path-integration due to slippage. Therefore, adaptive sensor calibration using a specific variant of Kohonen’s algorithm is applied in two cases to extract symbolic, e.g. geometric, information from the sub-symbolic sensor data, which is used to enhance position control by landmark mapping and orientation. In order to successfully handle the arising complex interactions, a heterogeneous control-architecture based on a parallel implementation of basic behaviours coupled by a rule-based central unit is proposed

Communication Between Khepera Mini Robots For Cooperative Positioning

Grünewald M, Iske B, Klahold J, et al. Communication Between Khepera Mini Robots For Cooperative Positioning. In: Proceedings of the International Conference Automatics and Informatics’03. Vol 1. Sofia, Bulgaria; 2003: 95-98

A Visualization Tool for the Mini-Robot Khepera: Behaviour Analysis and Optimization

Löffler A, Klahold J, Hußmann M, Rückert U. A Visualization Tool for the Mini-Robot Khepera: Behaviour Analysis and Optimization. In: Floreano D, Nicoud J-D, Mondada F, eds. Proceedings of the 5th International European Conference on Artificial Life (ECAL99). Vol 1674. Lausanne, Switzerland: Springer-Verlag; 1999: 329-333.The design of behavior generating control structures for real robots acting autonomously in a real and changing environment is a complex task. This is in particular true with respect to the debugging process, the documentation of the encountered behavior, its quantitative analysis and the final evaluation. To successfully implement such a behavior, it is vital to couple the synthesis on a simulator and the experiment on a real robot with a thorough analysis. The available simulator tools in general only allow behavioral snapshots and do not provide the option of online interference. In order to cure these shortcomings, a visualization tool for aposteriori graphical analysis of recorded data sets which gives access to all relevant internal states and parameters of the system is presented. The mini-robot Khepera has been chosen as experimentatory platform

The Dynamical Nightwatch's Problem Solved by the Autonomous Micro-Robot Khepera

Löffler A, Klahold J, Rückert U. The Dynamical Nightwatch's Problem Solved by the Autonomous Micro-Robot Khepera. In: Hao J-K, Lutton E, Ronald E, Schoenauer M, Snyers D, eds. Selected Papers of the 3rd European Conference on Artificial Evolution (AE97). Vol 1363. Nimes, France: Springer-Verlag; 1998: 303-313.In this paper, we present the implementation, both in a simulator and in a real-robot version, of an efficient solution to the so-called dynamical nightwatch’s problem on the micro-robot Khepera. The problem consists mainly in exploring a previously unknown environment while detecting, registering and recognizing light sources which may dynamically be turned on and off. At the end of each round a report is requested from the robot. Therein we made use of an agent-based approach and applied a self-organizing feature map in order to refine some of the behaviour generating control-modules

Test elektrischer Antriebe für Hybridfahrzeuge mittels Hardware-in-the-Loop Simulation

Hybridantriebe erweitern die bestehen Antirebstechnologien um eistungsfähige elektrische Maschinen und Speichervorrichtungen in verschiedenen Konfigurationen. Diese zusätzitchen Komponenten erhöhen Freiheitsgrade des gesamten Systems führen zu einer komplexen Verteilung auf mehrere Steuergeräte. Um dieser angestiegenen Komplexitat Rechnung zu tragen, muss die Entwicklungsumgebung sprechend angepasst werden. Hardware-in-the-Loop(HIL)Simulation ist im Entwicklungsprozess für einzelne Steuergeräte wle auch für den Test von Verbundsystemen eine etablierte Testmethode. Allerdings unterscheiden sich die Anforderungen an HIL Simulatoren für den Test von Steuergeräten für elektrische Antriebe deutlich von denen für z. B. Verbrennungsmotoren. Die Regelung eines elektrischen Antriebs erfordert eine signifikant höhere Echtzeitdynamlk, da diese mit 5 bis 20 kHz berechnet werden. Für die Echtzeitsimulation der elektrischen Mahschine ist somit eine optimierte I/O Schnittstelle entscheidend, die auf die spezifische Signale der Anwendung und das eingesetzte Echtzeit-Modell optimiert ist. Die Testumgebung muss für einen Verbund Steuergeräten ausgelegt werden, wobei diese entweder direkt angeschlossen oder simuliert werden

Neural Object Classification Using Ultrasonic Spectrum Analysis

Klahold J, Jürgens H, Rückert U. Neural Object Classification Using Ultrasonic Spectrum Analysis. In: Proceedings of the 2nd International Symposium on Autonomous Minirobots for Research and Edutainment (AMiRE). Brisbane, Australia; 2003: 219-228.This paper describes how reflected broadband sound signals are marked by interference phenomena if the surface of the ensonified object is structured. For an efficient extraction of features of the signal that relate to the surface structure of the object, the calculation of the cepstrum is introduced. A cylindrical test object is presented, which shows an angle independent and an angle dependent structure. This allows to specify the accuracy of the discrimination of structure sizes, that is based on a selected part of the cepstrum. In addition, the object can be used as a landmark for ultrasonic sensing. Classification of the cepstra is done by the statistical ‘One Nearest Neighbour’ (1NN) method as well as by a ‘Kohonen Self-Organising Feature Map’ (SOM). The results show, that changes in structure size down to 0.1mm are detectable

Ultrasonic Sensor for Mobile Mini-Robots Using Pseudo-Random Codes

Klahold J, Rautenberg J, Rückert U. Ultrasonic Sensor for Mobile Mini-Robots Using Pseudo-Random Codes. In: Rückert U, Sitte J, Witkowski U, eds. Proceedings of the 5th International Heinz Nixdorf Symposium: Autonomous Minirobots for Research and Edutainment (AMiRE01). Vol 97. Heinz Nixdorf Institut, Universität Paderborn; 2001: 225-232

Demonstration of a Visualization Tool for the Mini-Robot Khepera

Löffler A, Klahold J, Hußmann M, Rückert U. Demonstration of a Visualization Tool for the Mini-Robot Khepera. In: Web publication of the 5th International European Conference on Artificial Life (ECAL). Lausanne, Switzerland; 1999

Gard – An Intelligent System for Distributed Exploration of Landmine Fields Simulated by a Team of Khepera Robots

Manolov O, Iske B, Noykov S, et al. Gard – An Intelligent System for Distributed Exploration of Landmine Fields Simulated by a Team of Khepera Robots. In: Proceedings of the International Conference Automatics and Informatics’03. Vol 1. Sofia, Bulgaria; 2003: 199-202

Gard – An Intelligent System for Distributed Exploration of Landmine Fields Simulated by a Team of Khepera Robots

Manolov O, Iske B, Noykov S, et al. Gard – An Intelligent System for Distributed Exploration of Landmine Fields Simulated by a Team of Khepera Robots. In: Proceedings of the International Conference Automatics and Informatics’03. Vol 1. Sofia, Bulgaria; 2003: 199-202