Observer-based Controller for VTOL-UAVs Tracking using Direct Vision-Aided Inertial Navigation Measurements

This paper proposes a novel observer-based controller for Vertical Take-Off and Landing (VTOL) Unmanned Aerial Vehicle (UAV) designed to directly receive measurements from a Vision-Aided Inertial Navigation System (VA-INS) and produce the required thrust and rotational torque inputs. The VA-INS is composed of a vision unit (monocular or stereo camera) and a typical low-cost 6-axis Inertial Measurement Unit (IMU) equipped with an accelerometer and a gyroscope. A major benefit of this approach is its applicability for environments where the Global Positioning System (GPS) is inaccessible. The proposed VTOL-UAV observer utilizes IMU and feature measurements to accurately estimate attitude (orientation), gyroscope bias, position, and linear velocity. Ability to use VA-INS measurements directly makes the proposed observer design more computationally efficient as it obviates the need for attitude and position reconstruction. Once the motion components are estimated, the observer-based controller is used to control the VTOL-UAV attitude, angular velocity, position, and linear velocity guiding the vehicle along the desired trajectory in six degrees of freedom (6 DoF). The closed-loop estimation and the control errors of the observer-based controller are proven to be exponentially stable starting from almost any initial condition. To achieve global and unique VTOL-UAV representation in 6 DoF, the proposed approach is posed on the Lie Group and the design in unit-quaternion is presented. Although the proposed approach is described in a continuous form, the discrete version is provided and tested. Keywords: Vision-aided inertial navigation system, unmanned aerial vehicle, vertical take-off and landing, stochastic, noise, Robotics, control systems, air mobility, observer-based controller algorithm, landmark measurement, exponential stability

Heat transfer in oscillating flows with sudden change in cross section

Oscillating fluid flow (zero mean) with heat transfer, between two parallel plates with a sudden change in cross section, was examined computationally. The flow was assumed to be laminar and incompressible with inflow velocity uniform over the channel cross section but varying sinusoidally with time. Over 30 different cases were examined; these cases cover wide ranges of Re sub max (187.5 to 30000), Va (1 to 350), expansion ratio (1:2, 1:4, 1:8, and 1:12) and A sub r (0.68 to 4). Three different geometric cases were considered (asymmetric expansion and/or contraction, symmetric expansion/contraction, and symmetric blunt body). The heat transfer cases were based on constant wall temperature at higher (heating) or lower (cooling) value than the inflow fluid temperature. As a result of the oscillating flow, the fluid undergoes sudden expansion in one half of the cycle and sudden contraction in the other half. One heating case is examined in detail, and conclusions are drawn from all the cases (documented in detail elsewhere). Instantaneous friction factors and heat transfer coefficients, for some ranges of Re sub max and Va, deviated substantially from those predicted with steady state correlations

Nonlinear Deterministic Observer for Inertial Navigation using Ultra-wideband and IMU Sensor Fusion

Navigation in Global Positioning Systems (GPS)-denied environments requires robust estimators reliant on fusion of inertial sensors able to estimate rigid-body's orientation, position, and linear velocity. Ultra-wideband (UWB) and Inertial Measurement Unit (IMU) represent low-cost measurement technology that can be utilized for successful Inertial Navigation. This paper presents a nonlinear deterministic navigation observer in a continuous form that directly employs UWB and IMU measurements. The estimator is developed on the extended Special Euclidean Group $\mathbb{SE}_{2}\left(3\right)$ and ensures exponential convergence of the closed loop error signals starting from almost any initial condition. The discrete version of the proposed observer is tested using a publicly available real-world dataset of a drone flight. Keywords: Ultra-wideband, Inertial measurement unit, Sensor Fusion, Positioning system, GPS-denied navigation.Comment: 2023 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS

Software Engineering: A fundamental Approach to Automate and Interface Medical Electronic Systems with Computers in Healthcare Systems

The cost for application software and propriatry standards (i.e. data structure and formats) required for storing  clinical datasets  from  electronic  device  cause  the  use  of  time-consuming  paper-based  documentation  and/or  the  transfer  of electronic  lab  records  manually  to  the  PC  database systems  in  Mother-Offspring  Malaria  Study  (MOMS)  Laboratory Unit located in Morogoro Regional Hospital, Tanzania. We have explored the ability to extract laboratory results from Haematology  analyzer  machine  for  easy  management, access  and  storage.  The  methodology  and  tools  used  during  the study includes; site survey and hands-on practice for requirement engineering, visual basic 6.0 for interface design and Microsoft  Access  for  relational  database  design.  The  study  has  developed  a  model  “COmpose-TRAansmit-COnvent-COmpose” convention (acronym COTRACOCO) to implements an open serial port interface that required only a driver class to execute the labs outputs for storage in database with at run-time with less programming knowledge. The study demonstrated that the COTRACOCO convention presented is general and may promote a new paradigm for establishing the robust serial port communication systems for any digital devic

The Serological Findings of Parvo virus B19 and Neopterin Detection among Sickle cell Disease Patients and Blood Doners in the Kingdom of Bahrain

Introduction. Parvovirus B19 (PV B19) is a small, non-enveloped, ss DNA virus with an icosahedral capsid having a size of 18–26 nm. PV B19 transmits through respiratory droplets, blood transfusion and nosocomial infections that have also been documented recently. The virus targets the actively dividing Erythroid Progenitor Cells (EPCs) that are found in the human bone marrow, fetal liver and human umbilical cord. Methods. The study was particularly conducted on Sickle Cell Disease (SCD) patients and focuses on the determination of parvovirus B19 among Bahraini population by relying on their clinical status. The serological study of PV B19 was performed using Enzyme Linked Immunosorbent Assay (ELISA) technique and includes 150 SCD patientsand 100 healthy blood donors in which both males and females were employed. The samples were taken from the emergency unit of Salmania Medical Complex (SMC) and Ibrahim Khalil Kano Center (IKKC). Results. Of the 150 SCD patients, 100 were with vaso-occlusive crisis(VOC) and 50 non-vaso-occlusive crisis (NVOC). The three groups showed significantly higher percentages of PV B19 IgG but the percentage in SCD was relatively high compared to the control group of age-matched healthy donors – 70% of the VOC patients, 76% of the NVOC cases and 57% of blood donors were found to be IgG sero-positive. Discussion and Conclusion. PV B19 is a pathogenic virus and sometimes considered as life-threatening specifically for those individuals who have SCD due to which a risk of transient aplastic crisis increases. This virus is only associated with those patients whohave some hematological disorders such as hemolytic anemia and erythro-cytopenia. An effective screening test must be performed in the future to reduce the risk of PV B19 infection. Keywords: Aplastic Crisis, Seroprevalence, Bahraini Population, Genotypes, Vasoocclusive crisis, Neopteri

Antibodies against Merozoite Surface Protein 1 and 2 in Sudanese children

Background: Malaria is a serious childhood disease causing high morbidity and mortality despite control measures. Immunological control against malaria was initiated early, and immunity acquired by children in endemic areas, which is age and exposure dependant, differs in different endemic settings. The objective of the study was to determine antibodies against Merozoite surface protein-1 (MSP-I) and Merozoite surface protein-2 (MSP-2), and to determine their relation to the age of Sudanese children. Methodology: The study was descriptive, cross-sectional, conducted in Khartoum Children Emergency Hospital (KCEH). 150 children with positive blood films for P. falciparum malaria were classified according to age, and a blood sample was taken from each one, and tested for antibodies against MSP-I and MSP-2. Results: Antibodies to MSP-I and MSP-2 were 46% and 42% respectively. Sero-positivity and sero-negativity for both antigens were 26.6% and 42.7% respectively. Seropositivity to either MSP2 or MSP1antigen alone was present in 18.7% and 12% of patients respectively. High seropositivity (52.9%) was found in the age group 12-15 years of age. Conclusion: MSP-1 and MSP-2 antibodies in Sudanese children according to this study were age dependant, and findings were similar to what had been reported in some African countries.Key words: P. falciparum malaria, MSP-I, MSP-2

Effects of added phosphorus and zinc on yield and its components of corn

   Experiments were conducted for two seasons (2000/01 and 2001/02) to study the effects of added phosphorus and zinc fertilizers on yield and its components of corn(Zea mays L.) grown on Remaitab soil series, (fine, smectitic, isohyperthermic, Typic Haplusterts) at the Gezira Research Station Farm, Wad Medani, Sudan. Phosphorus was banded in the soil as triple superphosphate at three rates (0, 43 and 86 kg P2O5 ha-1). Zinc, as zinc sulphate, was also banded at three rates (0, 5 and 10 kg Zn ha-1). Nitrogen was broadcast as a basal dose in the form of urea at a recommended dose of 86 kg N ha-1. Experiments were arranged in a split-plot design with four replicates. The results indicated that applica-tion of both nutrients significantly (P<0.05) increased the number of cobs ha-1, the number and weight of grains/cob, 100 grain weight and grain yield. However, doubling the rate of P to 86 kg P2O5 ha-1 did not result in a significant difference over that of 43 kg P2O5 ha-1 for most parameters studied.  Application of both P rates (43 and 86 kg P2 O5 ha-1) each in combination with Zn rates (5 and 10 kg Zn ha-1) increased weight of grains per cob, 100 grain weight and grain yield as compared to other treatments. For attaining maximum yield, application of 43 kg P2O5 ha-1+ 10 kg Zn ha-1 banded in the soil at sowing is recommended, in addition to the recommended rate of nitrogen on the Remaitab soil series