Oliver Michler
Dresden University of Technology
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Publication
Featured researches published by Oliver Michler.
international conference on intelligent transportation systems | 2011
Philipp Schuricht; Oliver Michler; Bernard Bäker
Frequent necessary stops at red traffic signals and related braking and acceleration processes significantly affect the fuel consumption and emission rates of a vehicle. The efficiency-increasing potential (fuel saving potential) of a predictive driver assistance system proposing an intelligent vehicle speed adaption well in advance the intersection is examined by a traffic flow model-based simulation. The considered predictive speed assistance system is based on the transmission of traffic light controller information into the approaching vehicle. Besides information on the traffic light timing chart, provision of accurate information on current traffic conditions between the current position of the vehicle and the stop line are necessary for a majority of driving situations. Here, the use of queue length estimation (QLE) techniques based on commonly installed induction loop sensor systems is described to extend the functional benefit of the driver assistance system. From QLE data, two additional main indicators (distance to virtual stop line and time to cleared intersection) can be derived to calculate a energy-efficient speed profile. For a single vehicle approaching an isolated intersection signalized with a standard timing cycle fuel savings of 8–11% can be found. The benefit of a QLE-included control scheme of the assistance system is demonstrated by simulation. Simulation results show situation-specific fuel saving potential differences of up to 28% compared to a basic system control scheme (only traffic light timing information).
workshop on positioning navigation and communication | 2011
Markus Wehner; Robert Richter; Sven Zeisberg; Oliver Michler
Phase measurement based time-of-flight ranging techniques are a valid approach for radio-frequency distance measurements using a small relative bandwidth. Step-frequency radar enhances this approach for application on multiple frequencies. In case of presence of narrowband interference, distance calculations are possibly affected depending on the number of frequencies measured and the type of the antennae used. The Inverse Fast Fourier Transform (IFFT) tends to be robust against interferences compared to calculation of a weighted mean. Resolution of IFFT and therefore accuracy of the ranging result depends on the number of measurement taps available. In this paper, the Compressive Sampling (CS) approach is investigated to increase the resolution of IFFT. It is shown that the CS approach is applicable for SFR in such scenario. Field tests have been performed for verification using a commercial ranging system from ZigPos company with different prototype antennae to minimize multipath influence in indoor environment.
international conference on indoor positioning and indoor navigation | 2013
Richard Weber; Uwe Gosda; Oliver Michler; Julia Ringel
In this work we use wireless sensor networks (WSNs) to estimate positions for automated passenger registration with the purpose of an electronic ticketing application in public transport systems. The network is capable of measuring distances between the networks sensor nodes by phase-of-arrival (POA) ranging. In our application, the requirements regarding position accuracy are very demanding, due to the ranging biases caused by severe non-line-of-sight (NLOS) environments, i.e. highly reflective radio propagation. Hence, we suggest semidefinite programming (SDP) as a robust optimization algorithm for the localization process and apply a NLOS mitigation technique from literature to a modified cost function that may help to meet these requirements. Finally the proposed algorithm is compared with state-of-the-art positioning techniques. Testing with simulated and real measured data shows that the proposed SDP estimator outperforms the other positioning algorithms substantially, particularly in realistic NLOS environments.
workshop on positioning navigation and communication | 2012
Julia Engelbrecht; Georg Förster; Oliver Michler; Ralf Collmann
In recent years, indoor positioning has become more and more important for industrial and commercial usage. Advanced approaches using leaky coaxial cables (LCX) not only for radio coverage have been developed. This paper deals with the application of LCXs for indoor localization in a public transport test scenario, run by the Fraunhofer Institute for Transportation and Infrastructure Systems IVI Dresden. In this scenario different systems were tested in a real-vehicle environment and compared to each other. In addition those results are contrasted with a synthetic indoor-test carried out in a corridor of the University of Applied Sciences Dresden, in the following referred to as “academic” scenario. Furthermore, the positioning accuracy, which could be achieved by using standard LCXs and two reference systems are demonstrated.
loughborough antennas and propagation conference | 2014
Julia Engelbrecht; Tim Fuss; Uwe Schwark; Oliver Michler
Civil aviation is considering the use of wireless transmission technology for safety-related on-board machine-to-machine communications. The crucial factor is the availability of a globally harmonized radio frequency band with predictable characteristics in terms of signal propagation and interference induced by other users of that frequency band. Currently the International Telecommunication Union and the International Civil Aviation Organization are establishing the regulatory environment allowing the usage of the band 4.2-4.4 GHz for so-called Wireless Avionics Intra-Communications. A Wireless Avionics Intra-Communications system essentially provides highly reliable short-range radio links between two or more points on board an aircraft. Since the frequency band 4.2-4.4 GHz is also used for radio altimetry on board civil and state aircraft, it is important to understand the coupling mechanisms between WAIC systems and the Radio Altimeter system onboard the same aircraft as well as onboard different aircraft. For this reason an extensive measurement campaign as described in this paper was carried out. The purpose of this campaign was to assess the degree of coupling between the antennas of both systems for a variety of antenna constellations involving one or two commercial short-haul aircraft of type Airbus A320-200 and A321-200.
workshop on positioning navigation and communication | 2013
Uwe Gosda; Richard Weber; Oliver Michler; Sven Zeisberg; Erik Mademann
Localization techniques based on wireless sensor networks (WSNs) are an increasingly popular approach for estimating object positions in a wide area of applications. Nevertheless, accuracy and reliability of the WSN position estimates need to be increased for some applications, e.g. automated people registration in public transport vehicles. This goal can be achieved by incorporating additional sensors like cameras in the localization process. In this paper we introduce a novel data fusion approach for combining WSN position estimates and object positions detected in camera images. We project image coordinates to the WSN coordinate frame and modify an Extended Kalman Filter (EKF) for data fusion. We show how the object positions that arise from 2D camera images are used to reduce the variance of the combined position estimate. We test our method by tracking the movement of a person using WSN positioning and additional measurements obtained by people detection in the corresponding video scene.
workshop on positioning navigation and communication | 2011
Richard Weber; Robert Richter; Oliver Michler; Sven Zeisberg
We consider problems of wireless sensor network (WSN) — based localisation as a promising technology for highly accurate positioning solutions. Hence, this paper provides an overview on the results of synthetic data testing of an iterative positioning approach. Position estimation in WSNs is based on distance measuring by means of time-of-flight (TOF) ranging techniques. To employ radio frequency (RF) — based positioning here an iterative classical multidimensional scaling (C-MDS) approach is used for computing position estimates by applying the eigen-decomposition of an Eucledian kernel. The iterative process enables coping with not RF connected sensor nodes. Based on various simulations, we investigate this approach in terms of performance and especially convergence speed.
workshop on positioning navigation and communication | 2016
Richard Weber; Paul Balzer; Oliver Michler; Erik Mademann
In recent years, wireless sensor networks became popular for a wide range of mainstream applications. Closely related with this evolution, a problem for consumer market use emerged: How to initialize and setup the infrastructure automatically. This paper presents an approach to solve this problem. We present a novel approach how to build infrastructure maps only with anchor-mobile range measurements. The approach uses a baseline SLAM implementation in form of incremental posterior mapping. We adapt the approach by representing mobile posterior as well as anchor maps with probability grids similar to Markov Localization due to addressing the complex Range Only Simultaneous Localization and Mapping (RO-SLAM) problem. In urban areas mobiles are employed e.g. by pedestrians or bikes which feature a specific kinematic locomotion activity. Hence, we pair RO-SLAM with a SVM-based activity classifier in order to raise anchor mapping accuracy. Simulation results discuss algorithm convergence and demonstrate the accuracy improvement in the presence of activity information.
international conference on informatics in control automation and robotics | 2014
Paul Balzer; Toralf Trautmann; Oliver Michler
This paper presents a novel approach for an adaptive Extended Kalman Filter (EKF), which is able to handle bad signal quality caused by shading or loss of Doppler Effect for low cost Global Navigation Satellite System (GNSS) receiver and Inertial Measurement Unit (IMU) sensors fused in a loosely coupled way. It uses the estimated position error as well as the speed to calculate the standard deviation for the measurement uncertainty matrix of the Kalman Filter. The filter is very easy to implement, because some conversions of the measurement, as well as the state variables, are made to reduce the complexity of the Jacobians, which are used in the EKF filter algorithm. The filter implementation is tested within a simulation and with real data and shows significantly better performance, compared to a standard EKF. The developed filter is running in realtime on an embedded device and is able to perform position and attitude estimation of a vehicle with low cost sensors.
ieee international conference on models and technologies for intelligent transportation systems | 2017
Benjamin Reichelt; Hagen Ußler; Oliver Michler; Jorg Holfeld; Sven Eckelmann; Toralf Trautmann
The automotive industry is changing from conventional driving into connected and later on autonomous driving. The key enablers for this conversion are the interaction between the highly precise detection of traffic objects, the accurate localization and communication. The paper on hand conducts this issue through an investigation of the involved sensor systems. Using Vehicle-to-Vehicle communication via WLANp, an approach for relative positioning between traffic objects was proposed and realized. In this context, particularly the time delays have been considered as a crucial component. For the precise object localization, a 360° LiDAR system recorded an usual intersection situation. For improving the absolute position of the ego vehicle, an investigation with RTK-capable GNSS modules was conducted. Here, a base station increased the positionings accuracy significantly by transmitting the correction data to the rover at receiver side.