Complete list of publications

Temperature sensors used in exhaust systems of combustion engines have to measure enormous temperature differences within the shortest periods of time. This serves to protect the engine parts with respect to their temperature stability and to govern the energy efficient operation of the engine. Numerical calculations with the Finite Elements Method are used to estimate static-thermal measurement errors and dynamic characteristics primarily concerning medium specificity and construction of the temperature sensors. New test equipment requires comparing various thermometers under real conditions (high temperature steps and velocity). Prediction models are used to correct the dynamic behavior and to predict the fluid temperature faster accurately.

An interferometer-based metrological scanning probe microscope (SPM) is successfully integrated into our nanopositioning and nanomeasuring machine (NPM machine) for high-precision measurements with nanometre uncertainty over a range of 25 mm × 25 mm × 5 mm. Both devices were developed at the Institute of Process Measurement and Sensor Technology of Ilmenau University of Technology, Germany. Outstanding results were achieved for different measurement tasks. With the NPM machine, truly long-range and long-term measurements are possible. Due to the tip wear, an automatic SPM cantilever replacement is preferable. Such a tip replacement is also required for the integration of multifunctional nanoanalytics. For example, for Kelvin probe force microscopy (KPFM), the measurement of topography and surface potential with different SPM tips is necessary. For this purpose, an electromagnetic tip changer was designed. The tip changer comprises three SPM probes. In order to retrieve the previous tip positions, additional fiducial marks were developed. The repeatability of relocation is less than 10 nm. The automatic tip changer and fiducial marks are integrated into a sample holder. The tip changer in combination with fiducial marks allows scanning distances three times longer (with the same type of SPM probes) and multifunctional nanoanalytics (with different SPM probes with special properties). Sample KPFM measurements are demonstrated. The developed tip changer, including special fiducial marks, improves the performance and functionality of the NPM machine crucially.

Balances based on the principle of electromagnetic force compensation (EMC) represent the state of the art concerning uncertainty of measurement and achievable resolution. Due to the increasing number of applications of these systems in industry and research, there is a strong interest in improving the performance in terms of speed and accuracy. Especially the application in food or pharmaceutical filling plants demand the contrary goals of high resolution and repeatability and the derivation of a measurement signal in a short time. To fulfil these demands, the entire system and the interaction of its components have to be optimized. This leads to the requirement of accurate models, describing the behaviour of this complex mechatronic system both in open and closed control loop. In this paper we present an approach for the modelling of the entire system consisting of a mechanical part, an optical position indicator, a digital controller, and amplifier and the actuator composed of voice coil and permanent magnet. The simulations were carried out with Matlab Simulink and ANSYS. The models were validated by comparing the simulated results to measured signals. For both, the static and dynamic behaviour good agreement of simulation and measurement was obtained. The advantage of the presented approach is that the characteristical behaviour of the system can be described and optimized at a very early state of development. Hence, time consuming and costintensive manufacturing of early development state prototypes can be significantly reduced or even omitted.