EduBal: An open balancing robot platform for teaching control and system theory

In this work we present EduBal, an educational open-source hardware and software platform for a balancing robot. The robot is designed to be low-cost, safe and easy to use by students for control education. Along with the robot we present example tasks from system identification as well as SISO and MIMO control. Using Simulink, students can quickly implement their control algorithms on the robot. Individual control parameters can be tuned online while analyzing the resulting behavior in live signal plots. At RWTH Aachen University and ETH Zurich 28 units have so far been built and used in control classes. In first laboratory experiences students show high intrinsic motivation and creativity to apply the studied concepts of control theory to the real system.Comment: Accepted for publication at the 21st IFAC World Congress 202

Vegetation change in meso-xeric grasslands of the Swiss Jura Mts. over 40 years

Meso-xeric grasslands have declined sharply in Central Europe during the last century. These spe-cies-rich habitats are threatened by intensification or abandonment of agricultural use, eutrophication, climate change and landscape fragmentation. However, different studies in various regions of Central Europe are inconsistent in their findings about degree and direction of changes. We thus resurveyed the historical vegetation plots of the alliance Mesobromionin the Swiss Jura Mts. In 2020, we re-sampled 28 quasi-permanent vegetation plots originally recorded in 1980 to quantify potential vegetation change. Frequency of individual species, species diversity, 11 ecological indicator values and four functional traits, as well as the presence of diagnostic species of phytosociological alliances, were analysed. Further, a habitat classification and detrended correspondence analysis (DCA) were also performed. Species richness, indicator values for light availability and temperature, seed dispersal by animals and seed persistence had significantly decreased by 2020. Conversely, ecological indicator values for nutrient availability and soil moisture as well as community-weighted means for seed mass and canopy height had significantly increased. There were significantly fewer ruderal species, stress-tolerators, therophytes and herbaceous chamaephytes in 2020. In contrast, highly competitive species and hemicryptophytes had increased. Together, these findings indicate an increase in productivity over time. There were fewer specialized species in 2020 than in 1980, indicating a homogenization of the vegetation and a shift towards nutrient-rich pastures and meadows. The shift towards a later succession-al stage might indicate reduced grazing disturbance. Most of these sites are currently not included in an agri-environmental scheme. Partial differences of our findings from those reported elsewhere in Central Europe highlight the importance of regionally adapted conservation strategies in order to stop biodiver-sity loss in meso-xeric grasslands

Metastatic Hürthle cell carcinoma presenting with low free thyroxine, severe hypercalcemia and spurious growth hormone production

Objective: Hürthle cell tumors constitute about 5% of thyroid neoplasms. They have malignant potential, behaving very aggressively compared to other differentiated thyroid cancers. The objective of this case report is to describe a case of a Hürthle cell carcinoma with a single large metastasis in the liver presenting almost 17 years after hemithyroidectomy. We highlight the difficulties in making a histologic diagnosis and the unpredictable nature of this cancer. Methods: The patient history and biochemistry were detailed. Thyroid function tests analyzed on multiple platforms (single-photon emission computed tomography, dynamic magnetic resonance imaging, technetium-99m bone scan, and radioactive iodine) were used to aid biochemical and radiologic diagnosis. Results: The patient's thyroid function test showed persistently low free thyroxine concentrations with normal thyroid stimulating hormone and free triiodothyronine, suggesting rapid deiodination in the context of a large liver lesion. Radiologic and morphologic appearances of the liver lesion led to an initial misdiagnosis of primary hepato-cellular carcinoma, revised to metastatic Hürthle cell carcinoma after positive immunochemistry. Nonparathyroid hormone-related intractable hypercalcemia of malignancy with an unusual pattern of elevated 1,25-dihydroxyvitamin D and raised fibroblast growth factor 23 concentrations culminated in his demise. Conclusions: In Hürthle cell carcinomas treated with partial thyroidectomy, subsequent abnormal thyroid functions tests may herald a more sinister underlying diagnosis. The management of Hürthle cell carcinoma relies heavily on the initial histology results. Histologic diagnosis should be sought earlier in abnormal and suspicious distant masses. Malignant hypercalcemia poses a great challenge in delayed presentations and can prove resistant to conventional treatments

EduBal: An open balancing robot platform for teaching control and system theory

In this work we present EduBal, an educational open-source hardware and software platform for a balancing robot. The robot is designed to be low-cost, safe and easy to use by students for control education. Along with the robot we present example tasks from system identification as well as SISO and MIMO control. Using Simulink, students can quickly implement their control algorithms on the robot. Individual control parameters can be tuned online while analyzing the resulting behavior in live signal plots. At RWTH Aachen University and ETH Zurich 28 units have so far been built and used in control classes. In first laboratory experiences students show high intrinsic motivation and creativity to apply the studied concepts of control theory to the real system

EduBal: An open balancing robot platform for teaching control and system theory

In this work we present EduBal, an educational open-source hardware and software platform for a balancing robot. The robot is designed to be low-cost, safe and easy to use by students for control education. Along with the robot we present example tasks from system identification as well as SISO and MIMO control. Using Simulink, students can quickly implement their control algorithms on the robot. Individual control parameters can be tuned online while analyzing the resulting behavior in live signal plots. At RWTH Aachen University and ETH Zurich 28 units have so far been built and used in control classes. In first laboratory experiences students show high intrinsic motivation and creativity to apply the studied concepts of control theory to the real system.ISSN:2405-896