Marek Musial

Detection of Sensor Faults in Autonomous Helicopters

This paper presents a sensor fault detection and diagnosis system for autonomous helicopters. The system has been tested with the MARVIN autonomous helicopter. Fault detection is accomplished by evaluating any significant change in the behaviour of the vehicle with respect to the fault-free behaviour, which is estimated by using an observer. The effectiveness of the proposed approach is demonstrated by means of MARVIN experimental results.

ACTUATOR FAULT DETECTION IN AUTONOMOUS HELICOPTERS

Abstract This paper presents an actuator fault detection and diagnosis system for autonomous helicopters. The system has been tested with the MARVIN autonomous helicopter. Fault detection is accomplished by evaluating any significant change in the behaviour of the vehicle with respect to the fault-free behaviour, which is estimated by using an observer. The effectiveness of the proposed approach is demonstrated by means of MARVIN experimental results and simulations.

Mechanical model and control of an autonomous small size helicopter with a stiff main rotor

The mathematical description of the kinematics and dynamics of a model helicopter is presented. Using the derived closed form solution for simplified dynamics, a controller for an autonomous model helicopter is designed. This controller is composed of two loops: the inner loop for controlling the orientation of the main rotor plain and the outer loop to control the mission parameters like coordinates of some reference point, orientation or cruise velocity. The performance of the proposed controller is demonstrated for the case of position control in a computer simulation.

Embedded System Architecture of the Second Generation Autonomous Unmanned Aerial Vehicle MARVIN MARK II

MARVIN (multi-purpose aerial robot vehicle with intelligent navigation) Mark II (M2) is an autonomous unmanned aerial vehicle (UAV) that was build in 2005 (see Fig. 1). Its predecessor [1] was developed from 1997 to successfully win the International Aerial Robotic Competition (IARC) [2] in 2000. From 2002 to 2005 it was used in cooperation with other UAVs in the European research project COMETS [3].

Communication system for cooperative mobile robots using ad-hoc networks

Abstract This paper presents a distributed, master-less communication system currently used for communication in a fleet of heterogeneous unmanned aerial vehicles in the European project COMETS for wired and wireless links. Communication is realized using distributed shared memory (DSM) where each network node is holding full or part of the DSM. The coherency of the DSM is kept by a real-time aware protocol that provides quality of service guarantee and dynamic routing. Furthermore, an experiment is presented using the communication system on a wireless ad-hoc network.

Control and simulation of an autonomously flying model helicopter

Abstract MARVIN is a model-helicopter based flying robot, which is able to operate completely autonomously. It has been designed to fulfill the demands of the International Aerial Robotics Competition (IARC) Millennial Event 1998-2000. To improve the flight behavior, a mathematical model of the flight characteristics has been developed, which is used for simulation. The flight control algorithm is based on a hierarchy of PID controllers. The results of simulation and real flight experiments show similar behavior in many points but also that not all effects are taken into account, yet.

On-Line Timed Protocol Trace Analysis Based on Uncertain State Descriptions

This paper presents a new approach to the task of passive protocol tracing. The method called FollowSM for the first time meets all requirements of practical in-field use, including the checking of time constraints, the independence of the current state when starting the analysis, the admittance of nondeterminism, and on-line real time analysis capability. This is achieved by a suitable modeling of the implementation under test and the generalization of the tracing algorithm to operate on state information with any degree of uncertainty. FollowSM has been implemented as a prototype system and proved capable of minimizing the time required for troubleshooting.

Feed-Forward Learning: Fast Reinforcement Learning of Controllers

Reinforcement Learning (RL) approaches are, very often, rendered useless by the statistics of the required sampling process. This paper shows how very fastRL is essentially made possible by abandoning the state feedback during training episodes. The resulting new method, feed-forward learning(FF learning), employs a return estimator for pairs of a state and a feed-forward policysparameter vector. FF learning is particularly suitable for the learning of controllers, e.g. for robotics applications, and yields learning rates unprecedented in the RL context. This paper introduces the method formally and proves a lower bound on its performance. Practical results are provided from applying FF learning to several scenarios based on the collision avoidance behavior of a mobile robot.

MARVIN siegt im „Millennial Event”: Autonome Flugroboter

Der fliegende Roboter MARVIN ist ein mit Bordrechner und Sensoren aufgerusteter Modellhelikopter, der in Funkverbindung mit einer bodengestutzten Rechneranlage autonom operiert. Er wurde zwischen 1997 und 2000 in Projekt-Lehr-veranstaltungen an der TU Berlin gebaut. MARVIN schlug in einem internationalen Wettbewerb fur fliegende Roboter die nordamerikanische Konkurrenz. Die fur MARVIN neu entworfene Technik konnte fur zahlreiche Aufgaben kommerziell eingesetzt werden. Doch die Entwicklung zur industriellen Serienreife scheiterte bislang an wirtschaftlichen und gesetzlichen Hemmnissen.

MARVINs Sieg im „Millennial Event“

MARVIN ist ein autonom fliegender Beobachtungs- und Erkundungsroboter auf Basis eines Modellhubschraubers, der im Rahmen von Projekt-Lehrveranstaltungen fur die International Aerial Robotics Competition in Hanford, Washington, entwickelt wurde. In diesem Wettbewerb sollen in einem Katastrophenszenario Objekte und Personen lokalisiert werden. Am 30.06.2000 siegte MARVIN in der Millennial Event genannten Endausscheidung dieses Wettbewerbs mit Abstand vor neun US-amerikanischen und kanadischen Teams. Dieses Papier zeigt anhand mehrerer Beispiele auf, wie die bei MARVIN verfolgte Beschrankung auf minimale Losungen ausschlaggebend fur den Erfolg war. Minimale Losung bedeutet dabei die Minimierung von Gewicht, Stromverbrauch, Kosten und Systemkomplexitat unter Verzicht auf alles, was bei genauer Betrachtung uber die gestellten Anforderungen hinausgeht.