A Learning-Based Framework for Safe Human-Robot Collaboration with Multiple Backup Control Barrier Functions

Ensuring robot safety in complex environments is a difficult task due to actuation limits, such as torque bounds. This paper presents a safety-critical control framework that leverages learning-based switching between multiple backup controllers to formally guarantee safety under bounded control inputs while satisfying driver intention. By leveraging backup controllers designed to uphold safety and input constraints, backup control barrier functions (BCBFs) construct implicitly defined control invariance sets via a feasible quadratic program (QP). However, BCBF performance largely depends on the design and conservativeness of the chosen backup controller, especially in our setting of human-driven vehicles in complex, e.g, off-road, conditions. While conservativeness can be reduced by using multiple backup controllers, determining when to switch is an open problem. Consequently, we develop a broadcast scheme that estimates driver intention and integrates BCBFs with multiple backup strategies for human-robot interaction. An LSTM classifier uses data inputs from the robot, human, and safety algorithms to continually choose a backup controller in real-time. We demonstrate our method's efficacy on a dual-track robot in obstacle avoidance scenarios. Our framework guarantees robot safety while adhering to driver intention

a review

It is well documented that global warming is unequivocal. Dairy production systems are considered as important sources of greenhouse gas emissions; however, little is known about the sensitivity and vulnerability of these production systems themselves to climate warming. This review brings different aspects of dairy cow production in Central Europe into focus, with a holistic approach to emphasize potential future consequences and challenges arising from climate change. With the current understanding of the effects of climate change, it is expected that yield of forage per hectare will be influenced positively, whereas quality will mainly depend on water availability and soil characteristics. Thus, the botanical composition of future grassland should include species that are able to withstand the changing conditions (e.g. lucerne and bird's foot trefoil). Changes in nutrient concentration of forage plants, elevated heat loads and altered feeding patterns of animals may influence rumen physiology. Several promising nutritional strategies are available to lower potential negative impacts of climate change on dairy cow nutrition and performance. Adjustment of feeding and drinking regimes, diet composition and additive supplementation can contribute to the maintenance of adequate dairy cow nutrition and performance. Provision of adequate shade and cooling will reduce the direct effects of heat stress. As estimated genetic parameters are promising, heat stress tolerance as a functional trait may be included into breeding programmes. Indirect effects of global warming on the health and welfare of animals seem to be more complicated and thus are less predictable. As the epidemiology of certain gastrointestinal nematodes and liver fluke is favourably influenced by increased temperature and humidity, relations between climate change and disease dynamics should be followed closely. Under current conditions, climate change associated economic impacts are estimated to be neutral if some form of adaptation is integrated. Therefore, it is essential to establish and adopt mitigation strategies covering available tools from management, nutrition, health and plant and animal breeding to cope with the future consequences of climate change on dairy farming

Comparing Crisp and Fuzzy DEA Approaches for The Launch Vehicle Selection Problem of A Communication Satellite Operator

In space industry, launch vehicle selection for a satellite is a critical managerial and technical decision making problem. Depending on the selected launch vehicle, launch cost can vary from 20 % to 50 % of the total cost of a communication satellite that cost million dollars. The aim of this paper is to analyze several launch vehicle alternatives to boost a geostationary communication satellite into desired orbit under a Multi Criteria Decision Making (MCDM) scheme. For this purpose, variants of crisp and fuzzy Data Envelopment Analysis are utilized as a MCDM tool. In order to evaluate launch vehicle alternatives a criteria hierarchy, which is established by the experts working in communication sector, is used. The outcomes of the crisp and fuzzy DEA methods are compared with each other. As a result of the comparison it is observed that DEA variants ranked the alternatives differently but the launch vehicle Alternative 1 is mostly ranked first

Comparing Crisp and Fuzzy DEA Approaches for The Launch Vehicle Selection Problem of A Communication Satellite Operator

Uzay endüstrisinde, bir uydu için fırlatma aracı seçimi kritik bir idari ve teknik karar verme problemidir. Seçilen fırlatma aracına bağlı olarak fırlatma maliyeti, milyon dolarlık bir uydunun toplam maliyetinin yüzde 20'si ila 50'si arasında değişebilir. Bu çalışmanın amacı, istenilen yörüngeye bir yere eş zamanlı iletişim uydusunu fırlatmak için kullanılan fırlatma aracı alternatiflerini, Çok Kriterli Karar Verme (ÇKKV) yöntemleri kullanarak analiz etmektir. Bu amaçla, kesin ve bulanık Veri Zarflama Analizi (VZA) yönteminin versiyonları ÇKKV yöntemi olarak kullanılmıştır. Fırlatma aracı seçeneklerinin değerlendirilmesi için sektör uzmanları tarafından oluşturulan kriterler hiyerarşisi kullanılmıştır. Kesin ve bulanık VZA yöntemlerinin çıktıları kıyaslanmıştır. Kıyaslama sonucunda VZA versiyonlarının, seçenekleri farklı sıraladıkları ama Seçenek 1'in genellikle sıralamanın ilk sırasında yer aldığı gözlenmiştirIn space industry, launch vehicle selection for a satellite is a critical managerial and technical decision making problem. Depending on the selected launch vehicle, launch cost can vary from 20 % to 50 % of the total cost of a communication satellite that cost million dollars. The aim of this paper is to analyze several launch vehicle alternatives to boost a geostationary communication satellite into desired orbit under a Multi Criteria Decision Making (MCDM) scheme. For this purpose, variants of crisp and fuzzy Data Envelopment Analysis are utilized as a MCDM tool. In order to evaluate launch vehicle alternatives a criteria hierarchy, which is established by the experts working in communication sector, is used. The outcomes of the crisp and fuzzy DEA methods are compared with each other. As a result of the comparison it is observed that DEA variants ranked the alternatives differently but the launch vehicle Alternative 1 is mostly ranked firs

The effect of dietary protein imbalance during pregnancy on the growth, metabolism and circulatory metabolome of neonatal and weaned juvenile porcine offspring.

Protein imbalance during pregnancy affects women in underdeveloped and developing countries and is associated with compromised offspring growth and an increased risk of metabolic diseases in later life. We studied in a porcine model the glucose and urea metabolism, and circulatory hormone and metabolite profile of offspring exposed during gestation, to maternal isoenergetic low–high (LP-HC), high–low (HP-LC) or adequate (AP) protein–carbohydrate ratio diets. At birth, LP-HC were lighter and the plasma acetylcarnitine to free carnitine ratios at 1 day of life was lower compared to AP offspring. Plasma urea concentrations were lower in 1 day old LP-HC offspring than HP-LC. In the juvenile period, increased insulin concentrations were observed in LP-HC and HP-LC offspring compared to AP, as was body weight from HP-LC compared to LP-HC. Plasma triglyceride concentrations were lower in 80 than 1 day old HP-LC offspring, and glucagon concentrations lower in 80 than 1 day old AP and HP-LC offspring. Plasma urea and the ratio of glucagon to insulin were lower in all 80 than 1 day old offspring. Aminoacyl-tRNA, arginine and phenylala-nine, tyrosine and tryptophan metabolism, histidine and beta-alanine metabolism differed between 1 and 80 day old AP and HP-LC offspring. Maternal protein imbalance throughout pregnancy did not result in significant consequences in offspring metabolism compared to AP, indicating enor-mous plasticity by the placenta and developing offspring