Stephan Kallweit

• Professor
• Professor at FH Aachen

The use of industrial robots allows the precise manipulation of all components necessary for setting up a large-scale particle image velocimetry (PIV) system. The known internal calibration matrix of the cameras in combination with the actual pose of the industrial robots and the calculated transform from the fiducial markers to camera coordinates...

The use of industrial robots allows the precise manipulation of all components necessary for setting up a large-scale particle image velocimetry (PIV) system. The known internal calibration matrix of the cameras in combination with the actual pose of the industrial robots and the calculated transform from the fiducial markers to camera coordinates...

Wind energy represents the dominant share of renewable energies. The rotor blades of a wind turbine are typically made from composite material, which withstands high forces during rotation. The huge dimensions of the rotor blades complicate the inspection processes in manufacturing. The automation of inspection processes has a great potential to in...

Flexible production is a key element in modern industrial manufacturing. Autonomous mobile manipulators can be used to execute various tasks: from logistics, to pick and place, or handling. Therefore, autonomous robotic systems can even increase the flexibility of existing production environments. However, the application of robotic systems is chal...

We present an automated pipeline for the generation of synthetic datasets for six-dimension (6D) object pose estimation. Therefore, a completely automated generation process based on predefined settings is developed, which enables the user to create large datasets with a minimum of interaction and which is feasible for applications with a high obje...

The maintenance of wind turbines is of growing importance considering the transition to renewable energy. This paper presents a multi-robot-approach for automated wind turbine maintenance including a novel climbing robot. Currently, wind turbine maintenance remains a manual task, which is monotonous, dangerous, and also physically demanding due to...

In recent years, the rising demand for customised products has changed the requirements for industrial production. Nonetheless human workers are still an important part of the production process, especially in the area of final assembly. In the production of small series as well as customer-configured products, tools for different work tasks are us...

In this paper, we report on the H2020 funded project ROSIN and its outreach activities to South Africa. ROSIN is concerned with developing and maintaining high-quality software components for ROS-Industrial. ROS-Industrial is the industry branch of the Robot Operating System (ROS), a popular open source robot middleware. The ROSIN project is trying...

Purpose This paper aims to establish a standardized, quick, reliable and cost-efficient method of quality control (QC) in metal powder bed fusion (PBFM) based on process monitoring data. Design/methodology/approach Based on destructive testing results that emerged from a statistical investigation on powder bed fusion process exceeding reproducibil...

Mobile autonomous robotics is evolving quickly. Whether it is applied to specific scenarios like disaster areas or to industrial applications, mobile robots are part of the future world. The MBZIRC (Mohamed Bin Zayed International Robotics Challenge) addresses modern problems in the field of mobile robotics. The FH Aachen team competed in the three...

The rail business is challenged by long product life cycles and a broad spectrum of assembly groups and single parts. When spare part obsolescence occurs, quick solutions are needed. A reproduction of obsolete parts is often connected to long waiting times and minimum lot quantities that need to be purchased and stored. Spare part storage is theref...

Mobile autonomous robotics is on its way to industry. Beyond the useful logistics applications where the material for a manufacturing procedure is delivered on demand, the mobile manipulation of objects is still under development. The modern flexible production lines can be supported by autonomous industrial mobile manipulators (AIMM) acting as a c...

This work demonstrates how the interaction between particle image velocimetry (PIV) and robotics can massively increase measurement efficiency. The interdisciplinary approach is shown using the complex example of an automated, large scale, industrial environment: a typical automotive wind tunnel application. Both the high degree of flexibility in c...

Mobile Robotics is one of the highest rated future technologies and a fast growing market. For a modern approach of this topic-mobile robotics-the most accepted framework is the Robot Operating System ROS. Learning ROS is still a challenging topic, so an educational concept for qualifying students is presented. The ROS Summer School is a "hands-on"...

ROS Industrial (ROS-I) is an effort to deploy the Robot Operating System (ROS) for industrial manufacturing applications. The ROS-I activities are organised by the ROS Industrial consortium (RIC). With the EU-funded project ROSIN, which started in 2017, the ROS-I activities are further supported. The project will give out funds for developing ROS-I...

Today, more than 275.000 wind turbines generate over 400 GW electrical power worldwide. So the demand for maintenance constantly raises. Since September 2014 the University of Applied Sciences Aachen and partners develop SMART (Scanning, Monitoring, Analyzing, Repair and Transportation), a maintenance platform for wind turbines. The research projec...

The development of wind energy has been continuously promoted in Germany and is increasing since renewable energies law (EEG) took place in 2000. This trend combined with the aging of wind turbines blades (WTB) requires periodical and effective maintenance throughout the year. The biggest challenge of maintenance companies is to reach repair height...

Today, more than 275.000 wind turbines generate over 400 GW electrical power worldwide. So the demand for maintenance constantly raises. Since September 2014 the University of Applied Sciences Aachen and partners develop SMART (Scanning, Monitoring, Analyzing, Repair and Transportation), a maintenance platform for wind turbines. The research projec...

The rapid development in the wind energy market is exhausting the capability for upcoming maintenance needs. [1] While the reliability of mechanical parts, e.g. main bearing, generator, gears and main shaft evolved, rotor blade maintenance and improvement turn more and more into focus [2]. Since September 2014 University of Applied Sciences Aachen...

This paper presents typical flow structures around a 60%-scale wind-tunnel model of a Formula One (F1) car, using planar particle image velocimetry (PIV). The customized PIV system is permanently installed in a wind tunnel to help aerodynamicists in the development loop. The PIV results enhance the understanding of the mean velocity field in the tw...

Mit einer momentan installierten Gesamtleistung von ca. 30 GW sind Windenergieanlagen (WEA) maßgeblich an der Energieversorgung in Deutschland beteiligt. Jährlich werden ca. 2000 neue Anlagen installiert – ein Wachstum von ~12% [1]. Die Technologie zur Erzeugung elektrischer Energie aus Windenergie ist noch vergleichsweise jung und erfuhr in den le...

The production and assembly of customized products increases the demand for flexible automation systems. One approach is to remove the safety fences that separate human and industrial robot to combine their skills. This collaboration possesses a certain risk for the human co-worker, leading to numerous safety concepts to protect him. The human need...

To achieve consistent Drag reduction of airframe and nonlifting rotating systems of the Green Rotorcraft ITD, the EU launched the JTI CleanSky GRC2 project. In its framework, a CFD-based optimization activity has been carried out along with experimental tests on the ERICA tiltrotor configuration in order to analyse the effect on flow field and drag...

This study investigates unsteady characteristics of the wake behind a 28%-scale car model in a wind tunnel using highspeed planar particle image velocimetry (PIV). The car model is based on a hatchback passenger car that is known to have relatively high fluctuations in its aerodynamic loads. This study primarily focuses on the lateral motion of the...

To achieve consistent Drag reduction of airframe and nonlifting rotating systems of the Green Rotorcraft ITD, the EU launched the JTI CleanSky GRC2 project. In its framework, a CFD-based optimization activity has been carried out along with experimental tests on the ERICA tiltrotor configuration in order to analyse the effect on flow field and drag...

This paper describes an improvement of Additive Manufacturing (AM) to process products with complex inner and outer geometries such as turbine blades by using a combination of AM, optical measuring techniques and robotics. One problem of AM is the rough surface caused by the layer-by-layer 3D printing with granular material, so the geometries need...

The production and assembly of customized products increases the demand for flexible automation systems. One approach is to remove the safety fences that separate human and industrial robot to combine their skills. This collaboration possesses a certain risk for the human co-worker, leading to numerous safety concepts to protect him. The human need...

The main objective of our ROS Summer School series is to introduce MA level students to program mobile robots with the Robot Operating System (ROS). ROS is a robot middleware that is used by many research institutions world- wide. Therefore, many state-of-the-art algorithms of mobile robotics are available in ROS and can be deployed very easily. As...

In recent years a lot of research has focussed on introducing mobile robots into production scenarios. Mobile robots are already deployed in flexible supply chain applications, moving the parts, which are to be processed next, to the right machines on time. In mining industries, particularly when oper- ating underground, load-haul-dump vehicles are...

Modern Tunnel Boring Machines (TBMs) used in mines or for road construction often consist of several modules for the drill head and further equipment as well as wagons for carrying the mined material (dump). These machines can have a total length of up to 70 meters. In the mines, the machine has to be navigated over long stretches through the mine...

The turbulent flow velocity distribution in a cross section of the German reference standard for volume flow metering devices at the PTB Berlin is measured by LDV and Stereo PIV. The volume flow rate is calculated by integration of the acquired velocity profiles. With proper adjustment of the PIV processing parameters rather low measurement uncerta...

Through several decades many different models of prosthetic artificial heart valves(PHV) have been designed and optimized in order to enhance hemodynamic properties. These properties are not only material dependent but the major influence results from the mechanical assembly of the particularPHV. For the experimental assessment of the flow through...

The number of candidates waiting for a heart valve replacement rises yearly. Even though there is a trend toward implantation of biological valves or reconstruction, the prosthetic heart valves (PHVs) are still commonly used for implantation or as a part of cardiac assist devices in many countries worldwide. However, the hemodynamic consequences of...

Die Geschwindigkeitsverteilung in der Querschnittsebene einer Rohrströmung wird mit LDV und PIV ermittelt. Die Messungen werden sowohl untereinander qualitativ, als auch quantitativ - durch Ermittlung der Volumenströme - mit einem Referenz MID verglichen. Verschiedene Fehlereinflüsse werden diskutiert und Strategien zur Fehlerminimierung gegeben. Z...

The Particle-Image Velocimetry (PIV) is a meanwhile quite mature measuring method in its application on a 2-dimensional (2D) measuring plane for the collec-tion of 2 or 3 velocity-components (2C resp. 3C) within this plane (planar PIV). A disadvantage is the limitation to a plane of 1...5 mm thickness. For the measure-ment of the velocity field in...

This paper proposes a fault diagnostic method for pump running conditions. The method is a combination of a process modeling and a classification procedure. The pump head and hydraulic losses in the pipe system are modeled by two equations. The values of the coefficients in the equations are determined from measurable output variables of the pump....

Im Institut für Maschinenkonstruktion der Technischen Universität Berlin, Fachgebiet Hydraulische Strömungsmaschinen und Strömungstechnik, werden seit mehr als zehn Jahren laseroptische Verfahren zur Untersuchung von hydraulischen Strömungsmaschinen eingesetzt. Herkömmliche laseroptische Verfahren wie die Laser-Doppler-Velocimetry gestatten die zei...

Tbe laser-Doppler velocimetry (LDV) is a weil known instrument for measuring the flow-field in rotating machinery. Due to the measuring principle of LDV these flow-fields show only its periodic unsteadiness. The particle image velocimetry (PIV) can be used to measure the real unsteady flow-field. However, the PIV technique has some restrictions in...

The flow behind artificial prosthetic heart valves (PHV) is assessed in order to innovate designs for better qualitative and quantitative performance. One of the major problems is still blood damage, due to the interaction with the valve. It is of high clinical importance to optimize shear stresses loading, avoid cavitation and minimize the backflo...

To support the model of the buffet mechanism given by Lee [1] the present investigation aims at capturing the wave propagation in the flow field outside of the separation of a transonic buffet flow over a DRA 2303 supercritical airfoil using high-speed PIV. To show the sensitivity of the shock wave to upstream propagating sound waves, the flow fiel...