Energy-Efficient and Semi-automated Truck Platooning
Due to slipstream effects, platooning leads to a significant decrease of the fuel consumption of ... more Due to slipstream effects, platooning leads to a significant decrease of the fuel consumption of the heavy-duty vehicles (HDV). Measurements with a platoon consisting of three vehicles were performed at the Zalazone proving ground. The goal of these measurements was to get the static pressure at the front and the rear of the second vehicle to calibrate computational fluid dynamics simulation and to measure the fuel consumption directly. Measurements were done at a vehicle speed of 80 km/h and varying inter-vehicle distances. Platooning leads to a reduction of the pressure coefficients in the centre of the HDV front and an increase of the pressure coefficient at the top and the rear of the HDV. Furthermore, a reduction of the fuel consumption of the leading vehicle of 7.9% at an inter-vehicle distance of 6 m and 3.7% at a distance of 22 m was determined. A comparison to CFD simulation showed a similar fuel reduction for an inter-vehicle distance of 6 m and 22 m. CFD simulation showed...
This paper presents the development of a versatile sensor platform that is well-suited for autono... more This paper presents the development of a versatile sensor platform that is well-suited for autonomous data acquisition in environmental monitoring. The key advantages of the platform are its compact design, implemented onboard sensors, wireless communication and further standard interfaces to connect application specific sensors. The sensor system is subsequently simple to install and the costs for the preparation and execution of a measurement task are low. The paper provides details of the platform design and key characteristics as well as data acquisition-, communication-, and data storage strategy. A practical exemplary application in the field of environmental monitoring - the determination of acceleration of plants due to wind load - is presented.
Fourth International Conference on Advances in Steel Structures, 2005
Publisher Summary Thin-walled cylindrical structures have been found to display three distinctly ... more Publisher Summary Thin-walled cylindrical structures have been found to display three distinctly different stability failure modes under wind loading, depending on their geometrical and material properties. In low cylinders, the radial compression at the meridian facing the wind causes a buckling mode similar to the cylinders under constant radial compression, while very long cylinders display a failure mode characterized by buckling in the lower third of the structure at the side which faces away from the wind. The failure of medium-height cylinders is characterized by a number of horizontal ripple-like buckles in an area around the upper half of the meridian which faces the wind. The chapter explains that three different stability failure modes under wind loading can be observed depending on the geometry of a cylindrical structure.
Measuring the distribution of gas concentration is a very common problem in a variety of technolo... more Measuring the distribution of gas concentration is a very common problem in a variety of technological fields. Depending on the detectability of the gas, as well as the technological progress of the sector, different methods are used. In this paper, we present a device and methods to detect the ammonia concentration distribution in the exhaust system of diesel engines in order to increase the performance of the exhaust aftertreatment system. The device has been designed for usage on a hot gas test bench simulating exhaust gas conditions. It consists of multiple optical beams measuring ammonia line concentrations by applying nondispersive absorption spectroscopy in the deep ultraviolet region. The detectors consist of photodiodes allowing high sampling rates up to 3 kHz while providing a high signal-to-noise ratio. A detection limit of only 1 ppm has been achieved despite the short path length of only eight centimeters. The obtained line concentrations form an inverse problem. The me...
Bridge weigh-in-motion (BWIM) systems capture and record axle weights and distances, gross weight... more Bridge weigh-in-motion (BWIM) systems capture and record axle weights and distances, gross weights and velocities of vehicles passing over a bridge structure that serves as a measurement site. All sensors for such a BWIM system are typically mounted off the road and minimise the impact on the passing traffic. In the present paper a methodology is described that allows for the computer based extraction of accurate vehicle data from measurement signals in a BWIM system. The proposed methodology combines wavelet analysis with an optimization procedure. It is fast enough to serve as a real-time application and detect vehicle data with great accuracy. Moreover, a solution to the practical problem of sensor calibration on the bridge site is presented which has the potential to replace the use of test trucks for this purpose with statistical methods.
Sensors, Systems, and Next-Generation Satellites IV, 2001
ABSTRACT 12 The detection of benzene and other organic compounds in vehicle exhaust by FT-IR-spec... more ABSTRACT 12 The detection of benzene and other organic compounds in vehicle exhaust by FT-IR-spectroscopy is seriously limited by the strong interference of carbon dioxide and the rather weak absorption coefficient of the gases. Therefore, a measurement device was developed which separates the components of interest (mostly VOCs) from carbon dioxide, water and nitric oxide. In addition the VOCs have to be pre- concentrated. To avoid condensation of VOCs the measurements have to take place at higher temperatures. The vehicle exhaust was led through an activated charcoal tube where the organic compounds were adsorbed. Afterwards, the charcoal tube was heated in a furnace, the VOCs were desorbed thermically and were carried by (heated) nitrogen into a gas cell with a path-length of 10 m where the concentration of the different species was measured. With the help of this measurement device a lot of VOC- components like benzene, toluene, and xylene were detected successfully. Measurements were performed on an engine test bed and a chassis dynamometer for heavy duty vehicles. The detection limit of most of the VOCs was about 2 to 3 ppb for a sampling time of 20 min. Calibration measurements showed an accuracy of 15%.
ABSTRACT The quantification of benzene in FTIR spectra is restricted by the interference of benze... more ABSTRACT The quantification of benzene in FTIR spectra is restricted by the interference of benzene with carbon dioxide. In this paper different methods are presented to overcome these problems with a detector of medium resolution of 0.5 cm-1. The experiments were performed either in a 10 m gas cell or as open path experiments. One method compares the peak at 673.76 cm-1 with the strongest absorption band of benzene in the single beam spectrum to the neighboring peaks, one method analyzes the shape of the peak at 674 cm-1. Another method works with an artificial background and the latest methods analyze the absorbance spectrum and serve as a reference. The results from all these methods agreed very well down to the level of 30 to 50 ppb.
In situ optical measurement systems for gas detection with high temporal resolution enable new po... more In situ optical measurement systems for gas detection with high temporal resolution enable new possibilities of detection opportunities for continuous pipe gas streams. A tomographic absorption-based measurement system has been developed to detect the ammonia (NH3) concentration distribution within an exhaust pipe on a hot gas test bench. Multiple ammonia line concentrations are measured in situ by applying nondispersive absorption spectroscopy in the deep ultraviolet (DUV) region. The detectors consist of photodiodes in combination with optimized transimpedance amplifiers (TIV) allowing high sampling rates up to 3 kHz while providing a high signal-to-noise ratio (SNR). Despite the short path length of only eight centimeters a detection limit of 1 ppm has been achieved.
This paper presents the development of a versatile sensor platform used for autonomous data acqui... more This paper presents the development of a versatile sensor platform used for autonomous data acquisition. The key advantages of the platform are its compact design, implemented onboard sensors, standard interfaces to connect application specific sensors and subsequently simple installation and low costs for the preparation of a measurement task. The paper provides details of the platform design and key characteristics. Practical exemplary applications in the field of automotive sensing, covering thermal management related and passenger comfort related measurement tasks, are presented.
This paper presents a non-invasive measurement method to detect and characterize failures and mat... more This paper presents a non-invasive measurement method to detect and characterize failures and material imperfections in total joint prostheses based on acceleration measurement. Therefore, a prototype sensor has been developed to fulfill the requirements of a medical-technical sensor. This sensor has been tested on patients with total hip arthroplasty. Special emphasis is put on the real-time processing of measurement data by means of intelligent signal processing as well as reliable and repeatable measurement procedures, including standardized positions for the sensor front-end and a standardized motion-sequence the patient is performing.
A three dimensional force measurement system was integrated in a climbing hold. The force measure... more A three dimensional force measurement system was integrated in a climbing hold. The force measurement system consisted of three orthogonally mounted platform load cells. Data acquisition and power supply of the load cells was performed by a wireless data acquisition system ViFDAQ. Data was transferred by ViFDAQ to a nearby laptop by a wireless Bluetooth connection. Measurements were done during a regional climbing competition. The instrumented climbing hold was mounted in one of the climbing routes. The forces the athletes exerted on the climbing hold to reach the top were measured. Force data was analyzed and compared to the actual ranking of the athlete in this competition.
Sensors, Systems, and Next-Generation Satellites IV, 2001
ABSTRACT 12 The emission behavior of road vehicles is usually estimated by application of emissio... more ABSTRACT 12 The emission behavior of road vehicles is usually estimated by application of emission factors and models. The validity of such factors or models in real world situations can be investigated by tunnel measurements, because road tunnels can be considered as big laboratories with well known boundary conditions. Tunnel experiments were carried out in the 10 km long Plabutschtunnel near Graz, Austria for a period of six weeks in November 1998 and another four weeks in May 1999. A UV- DOAS-system was operated in open-path mode located some 4 km inside the tunnel with pathlengths of 220 m to 430 m. To have an idea about the uniformity of the pollutant air mixture within the path, a comparison of NO2 measurements performed with a standard chemiluminescent analyser (point measurement) and the DOAS system (open-path measurement) was done. Therefore a standard air quality monitoring-system (AQM) in a container was installed in a niche inside the tunnel on one end of the DOAS path. The analysis of data showed good agreement of emissions derived from the measurements with the existing PC and HDV emission factors for CO. This was not the case for benzene and NOx emissions obtained from heavy duty vehicles.
ABSTRACT The numerical prediction of underhood local temperatures represents a challenging field ... more ABSTRACT The numerical prediction of underhood local temperatures represents a challenging field in the development of passenger cars. The reliability of computational fluid dynamics (CFD) results is depending upon numerics and employing appropriate physical models which can strongly affect the quality of results and the overall simulation time. The purpose of this paper is to analyze and validate the simulation of heat transfer phenomena in a vehicle’s underbody through the comparison with experimental data. The measurements are obtained from thermal sensors mounted on a passenger car during a highway drive. Furthermore, the radiative boundary conditions are defined through the post-processing of thermographic camera images. The numerical results of a commercial CFD code are finally compared with the experimental data on surface temperatures of the vehicle’s underbody.
Due to the formation of basal ice during the winter, the undercooled scree slopes emit cold strea... more Due to the formation of basal ice during the winter, the undercooled scree slopes emit cold streams of air during the warm season. Often condensation-water mires can be found here. The study investigated the invertebrate fauna of the interstitial with pitfall traps (1 470 „trap months“) at five talus sites in the eastern Alps of Styria (Austria). Results revealed the occurrence of a highly independent cold-adapted fauna with rare and endangered arthropods (e. g. 13 first records of spiders in the Styrian province), alpine species far below their known vertical distribution, species with arcto-alpine and boreo-montane distribution ranges and a high percentage of endemic species. In view of several species having a clear-cut niche separation along the temperature gradient, the current climate warming poses a serious threat to these species communities. Furthermore some endangering threats have been identified which can be mitigated by protective measures on a local scale.
Energy-Efficient and Semi-automated Truck Platooning
Due to slipstream effects, platooning leads to a significant decrease of the fuel consumption of ... more Due to slipstream effects, platooning leads to a significant decrease of the fuel consumption of the heavy-duty vehicles (HDV). Measurements with a platoon consisting of three vehicles were performed at the Zalazone proving ground. The goal of these measurements was to get the static pressure at the front and the rear of the second vehicle to calibrate computational fluid dynamics simulation and to measure the fuel consumption directly. Measurements were done at a vehicle speed of 80 km/h and varying inter-vehicle distances. Platooning leads to a reduction of the pressure coefficients in the centre of the HDV front and an increase of the pressure coefficient at the top and the rear of the HDV. Furthermore, a reduction of the fuel consumption of the leading vehicle of 7.9% at an inter-vehicle distance of 6 m and 3.7% at a distance of 22 m was determined. A comparison to CFD simulation showed a similar fuel reduction for an inter-vehicle distance of 6 m and 22 m. CFD simulation showed...
This paper presents the development of a versatile sensor platform that is well-suited for autono... more This paper presents the development of a versatile sensor platform that is well-suited for autonomous data acquisition in environmental monitoring. The key advantages of the platform are its compact design, implemented onboard sensors, wireless communication and further standard interfaces to connect application specific sensors. The sensor system is subsequently simple to install and the costs for the preparation and execution of a measurement task are low. The paper provides details of the platform design and key characteristics as well as data acquisition-, communication-, and data storage strategy. A practical exemplary application in the field of environmental monitoring - the determination of acceleration of plants due to wind load - is presented.
Fourth International Conference on Advances in Steel Structures, 2005
Publisher Summary Thin-walled cylindrical structures have been found to display three distinctly ... more Publisher Summary Thin-walled cylindrical structures have been found to display three distinctly different stability failure modes under wind loading, depending on their geometrical and material properties. In low cylinders, the radial compression at the meridian facing the wind causes a buckling mode similar to the cylinders under constant radial compression, while very long cylinders display a failure mode characterized by buckling in the lower third of the structure at the side which faces away from the wind. The failure of medium-height cylinders is characterized by a number of horizontal ripple-like buckles in an area around the upper half of the meridian which faces the wind. The chapter explains that three different stability failure modes under wind loading can be observed depending on the geometry of a cylindrical structure.
Measuring the distribution of gas concentration is a very common problem in a variety of technolo... more Measuring the distribution of gas concentration is a very common problem in a variety of technological fields. Depending on the detectability of the gas, as well as the technological progress of the sector, different methods are used. In this paper, we present a device and methods to detect the ammonia concentration distribution in the exhaust system of diesel engines in order to increase the performance of the exhaust aftertreatment system. The device has been designed for usage on a hot gas test bench simulating exhaust gas conditions. It consists of multiple optical beams measuring ammonia line concentrations by applying nondispersive absorption spectroscopy in the deep ultraviolet region. The detectors consist of photodiodes allowing high sampling rates up to 3 kHz while providing a high signal-to-noise ratio. A detection limit of only 1 ppm has been achieved despite the short path length of only eight centimeters. The obtained line concentrations form an inverse problem. The me...
Bridge weigh-in-motion (BWIM) systems capture and record axle weights and distances, gross weight... more Bridge weigh-in-motion (BWIM) systems capture and record axle weights and distances, gross weights and velocities of vehicles passing over a bridge structure that serves as a measurement site. All sensors for such a BWIM system are typically mounted off the road and minimise the impact on the passing traffic. In the present paper a methodology is described that allows for the computer based extraction of accurate vehicle data from measurement signals in a BWIM system. The proposed methodology combines wavelet analysis with an optimization procedure. It is fast enough to serve as a real-time application and detect vehicle data with great accuracy. Moreover, a solution to the practical problem of sensor calibration on the bridge site is presented which has the potential to replace the use of test trucks for this purpose with statistical methods.
Sensors, Systems, and Next-Generation Satellites IV, 2001
ABSTRACT 12 The detection of benzene and other organic compounds in vehicle exhaust by FT-IR-spec... more ABSTRACT 12 The detection of benzene and other organic compounds in vehicle exhaust by FT-IR-spectroscopy is seriously limited by the strong interference of carbon dioxide and the rather weak absorption coefficient of the gases. Therefore, a measurement device was developed which separates the components of interest (mostly VOCs) from carbon dioxide, water and nitric oxide. In addition the VOCs have to be pre- concentrated. To avoid condensation of VOCs the measurements have to take place at higher temperatures. The vehicle exhaust was led through an activated charcoal tube where the organic compounds were adsorbed. Afterwards, the charcoal tube was heated in a furnace, the VOCs were desorbed thermically and were carried by (heated) nitrogen into a gas cell with a path-length of 10 m where the concentration of the different species was measured. With the help of this measurement device a lot of VOC- components like benzene, toluene, and xylene were detected successfully. Measurements were performed on an engine test bed and a chassis dynamometer for heavy duty vehicles. The detection limit of most of the VOCs was about 2 to 3 ppb for a sampling time of 20 min. Calibration measurements showed an accuracy of 15%.
ABSTRACT The quantification of benzene in FTIR spectra is restricted by the interference of benze... more ABSTRACT The quantification of benzene in FTIR spectra is restricted by the interference of benzene with carbon dioxide. In this paper different methods are presented to overcome these problems with a detector of medium resolution of 0.5 cm-1. The experiments were performed either in a 10 m gas cell or as open path experiments. One method compares the peak at 673.76 cm-1 with the strongest absorption band of benzene in the single beam spectrum to the neighboring peaks, one method analyzes the shape of the peak at 674 cm-1. Another method works with an artificial background and the latest methods analyze the absorbance spectrum and serve as a reference. The results from all these methods agreed very well down to the level of 30 to 50 ppb.
In situ optical measurement systems for gas detection with high temporal resolution enable new po... more In situ optical measurement systems for gas detection with high temporal resolution enable new possibilities of detection opportunities for continuous pipe gas streams. A tomographic absorption-based measurement system has been developed to detect the ammonia (NH3) concentration distribution within an exhaust pipe on a hot gas test bench. Multiple ammonia line concentrations are measured in situ by applying nondispersive absorption spectroscopy in the deep ultraviolet (DUV) region. The detectors consist of photodiodes in combination with optimized transimpedance amplifiers (TIV) allowing high sampling rates up to 3 kHz while providing a high signal-to-noise ratio (SNR). Despite the short path length of only eight centimeters a detection limit of 1 ppm has been achieved.
This paper presents the development of a versatile sensor platform used for autonomous data acqui... more This paper presents the development of a versatile sensor platform used for autonomous data acquisition. The key advantages of the platform are its compact design, implemented onboard sensors, standard interfaces to connect application specific sensors and subsequently simple installation and low costs for the preparation of a measurement task. The paper provides details of the platform design and key characteristics. Practical exemplary applications in the field of automotive sensing, covering thermal management related and passenger comfort related measurement tasks, are presented.
This paper presents a non-invasive measurement method to detect and characterize failures and mat... more This paper presents a non-invasive measurement method to detect and characterize failures and material imperfections in total joint prostheses based on acceleration measurement. Therefore, a prototype sensor has been developed to fulfill the requirements of a medical-technical sensor. This sensor has been tested on patients with total hip arthroplasty. Special emphasis is put on the real-time processing of measurement data by means of intelligent signal processing as well as reliable and repeatable measurement procedures, including standardized positions for the sensor front-end and a standardized motion-sequence the patient is performing.
A three dimensional force measurement system was integrated in a climbing hold. The force measure... more A three dimensional force measurement system was integrated in a climbing hold. The force measurement system consisted of three orthogonally mounted platform load cells. Data acquisition and power supply of the load cells was performed by a wireless data acquisition system ViFDAQ. Data was transferred by ViFDAQ to a nearby laptop by a wireless Bluetooth connection. Measurements were done during a regional climbing competition. The instrumented climbing hold was mounted in one of the climbing routes. The forces the athletes exerted on the climbing hold to reach the top were measured. Force data was analyzed and compared to the actual ranking of the athlete in this competition.
Sensors, Systems, and Next-Generation Satellites IV, 2001
ABSTRACT 12 The emission behavior of road vehicles is usually estimated by application of emissio... more ABSTRACT 12 The emission behavior of road vehicles is usually estimated by application of emission factors and models. The validity of such factors or models in real world situations can be investigated by tunnel measurements, because road tunnels can be considered as big laboratories with well known boundary conditions. Tunnel experiments were carried out in the 10 km long Plabutschtunnel near Graz, Austria for a period of six weeks in November 1998 and another four weeks in May 1999. A UV- DOAS-system was operated in open-path mode located some 4 km inside the tunnel with pathlengths of 220 m to 430 m. To have an idea about the uniformity of the pollutant air mixture within the path, a comparison of NO2 measurements performed with a standard chemiluminescent analyser (point measurement) and the DOAS system (open-path measurement) was done. Therefore a standard air quality monitoring-system (AQM) in a container was installed in a niche inside the tunnel on one end of the DOAS path. The analysis of data showed good agreement of emissions derived from the measurements with the existing PC and HDV emission factors for CO. This was not the case for benzene and NOx emissions obtained from heavy duty vehicles.
ABSTRACT The numerical prediction of underhood local temperatures represents a challenging field ... more ABSTRACT The numerical prediction of underhood local temperatures represents a challenging field in the development of passenger cars. The reliability of computational fluid dynamics (CFD) results is depending upon numerics and employing appropriate physical models which can strongly affect the quality of results and the overall simulation time. The purpose of this paper is to analyze and validate the simulation of heat transfer phenomena in a vehicle’s underbody through the comparison with experimental data. The measurements are obtained from thermal sensors mounted on a passenger car during a highway drive. Furthermore, the radiative boundary conditions are defined through the post-processing of thermographic camera images. The numerical results of a commercial CFD code are finally compared with the experimental data on surface temperatures of the vehicle’s underbody.
Due to the formation of basal ice during the winter, the undercooled scree slopes emit cold strea... more Due to the formation of basal ice during the winter, the undercooled scree slopes emit cold streams of air during the warm season. Often condensation-water mires can be found here. The study investigated the invertebrate fauna of the interstitial with pitfall traps (1 470 „trap months“) at five talus sites in the eastern Alps of Styria (Austria). Results revealed the occurrence of a highly independent cold-adapted fauna with rare and endangered arthropods (e. g. 13 first records of spiders in the Styrian province), alpine species far below their known vertical distribution, species with arcto-alpine and boreo-montane distribution ranges and a high percentage of endemic species. In view of several species having a clear-cut niche separation along the temperature gradient, the current climate warming poses a serious threat to these species communities. Furthermore some endangering threats have been identified which can be mitigated by protective measures on a local scale.
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Papers by Bernhard Lechner