Design a Robust RST Controller for Stabilization of a Tri-Copter UAV

Research on the tri-rotor aerial robot is due to extra efficiency over other UAV’s regarding stability, power and size requirements. We require a controller to achieve 6-Degree Of Freedom (DOF), for such purpose, we propose the RST controller to operate our tri-copter model. A MIMO model of a tri-copter aerial robot is challenged in the area of control engineering. Ninestates of output control dynamics are treated individually. We designed dynamic controllers to stabilize the parameters of an UAV. The resulting system control algorithm is capable of stabilizing our UAV to perform numerous operations autonomously. The estimation and simulation implemented inMATLAB, Simulink to verify the results. All real flight test results are presented to prove the success of the planned control structure

Attitude and Altitude Control of Trirotor UAV by Using Adaptive Hybrid Controller

The paper presents an adaptive hybrid scheme which is based on fuzzy regulation, pole-placement, and tracking (RST) control algorithm for controlling the attitude and altitude of trirotor UAV. The dynamic and kinematic model of Unmanned Aerial Vehicle (UAV) is unstable and nonlinear in nature with 6 degrees of freedom (DOF); that is why the stabilization of aerial vehicle is a difficult task. To stabilize the nonlinear behavior of our UAV, an adaptive hybrid controller algorithm is used, in which RST controller tuning is performed by adaptive gains of fuzzy logic controller. Simulated results show that fuzzy based RST controller gives better robustness as compared to the classical RST controller

Adaptive Synergetic Controller for Stabilizing the Altitude and Angle of Mini Helicopter

This research proposes ASC (Adaptive Synergetic Controller) for the nonlinear model of MH (Mini Helicopter) to stabilize the desired altitude and angle. The model of MH is highly nonlinear, underactuated and multivariable in nature due to its dynamic uncertainties and restrictions of velocities during the flight. ASC can force the tracking errors of the system states converges to zero in a finite interval of time. The MH system requires smooth controller and fast precise transition response from initial state till the desired state, therefore the parametric calculations and simulations can be done by the proposed ASC algorithm. It is validated that the above simulated results of the proposed controller have a better convergence rate and smoother stability response in order to track the desired altitude and angle when compared with SMC (Sliding Mode Controller). Moreover, it does not need any linearization, transformation and variations in the system model

A Survey on Recent Trends of PIO and Its Variants Applied for Motion Planning of Dynamic Agents

Pigeon Inspired Optimization (PIO) algorithm is gaining popularity since its development due to faster convergence ability with great efficiencies when compared with other bio-inspired algorithms. The navigation capability of homing pigeons has been precisely used in Pigeon Inspired Optimization algorithm and continuous advancement in existing algorithms is making it more suitable for complex optimization problems in various fields. The main theme of this survey paper is to introduce the basics of PIO along with technical advancements of PIO for the motion planning techniques of dynamic agents. The survey also comprises of findings and limitations of proposed work since its development to help the research scholar around the world for particular algorithm selection especially for motion planning. This survey might be extended up to application based in order to understand the importance of algorithm in future studies

Motion Planning of UAV Swarm: Recent Challenges and Approaches

The unmanned aerial vehicle (UAV) swarm is gaining massive interest for researchers as it has huge significance over a single UAV. Many studies focus only on a few challenges of this complex multidisciplinary group. Most of them have certain limitations. This paper aims to recognize and arrange relevant research for evaluating motion planning techniques and models for a swarm from the viewpoint of control, path planning, architecture, communication, monitoring and tracking, and safety issues. Then, a state-of-the-art understanding of the UAV swarm and an overview of swarm intelligence (SI) are provided in this research. Multiple challenges are considered, and some approaches are presented. Findings show that swarm intelligence is leading in this era and is the most significant approach for UAV swarm that offers distinct contributions in different environments. This integration of studies will serve as a basis for knowledge concerning swarm, create guidelines for motion planning issues, and strengthens support for existing methods. Moreover, this paper possesses the capacity to engender new strategies that can serve as the grounds for future work

A comprehensive review of scab disease detection on Rosaceae family fruits via UAV imagery

Disease detection in plants is essential for food security and economic stability. Unmanned aerial vehicle (UAV) imagery and artificial intelligence (AI) are valuable tools for it. The purpose of this review is to gather several methods used by our peers recently, hoping to provide some knowledge and assistance for researchers and farmers so that they can employ these technologies more advantageously. The studies reviewed in this paper focused on Scab detection in Rosaceae family fruits. Feature extraction, segmentation, and classification methods for processing the UAV-obtained images and detecting the diseases are discussed briefly. The advantages and limitations of diverse kinds of UAVs and imaging sensors are also explained. The widely applied methods for image analysis are machine learning (ML)-based models, and the extensively used UAV platforms are rotary-wing UAVs. Recent technologies that cope with challenges related to disease detection using UAV imagery are also detailed in this paper. Some challenging issues such as higher costs, limited batteries and flying time, huge and complex data, low resolution, and noisy images, etc., still require future consideration. The prime significance of this paper is to promote automation and user-friendly technologies in Scab detection

Toluidine blue: Yet another low cost method for screening oral cavity tumour margins in Third World countries

Objective: To use toluidine blue intra-operatively to identify tumour involved margins after the removal of oral cavity squamous cell carcinoma, and to compare the findings with those of final histopathology.Methods: The study was conducted at the Aga Khan University Hospital from December 1, 2009, to March 14, 2010, and comprised 56 consecutive patients with biopsy-proven squamous cell carcinoma of oral cavity regardless of grade and stage of tumour. Intra-operatively toluidine blue was used on the resected tumour margins and the staining patterns were assessed. Results were then compared with the final histopathology report.Results: A total of 11(19.64%) margins were positive with toluidine blue staining out of which 8 (14.28%) were false positive. Sensitivity and specificity was found to be 100% and 84.9% respectively with a positive predictive value of 27.2%; a negative predictive value of 100%; and diagnostic accuracy of 85.71%.Conclusion: Toluidine blue costs only Rs25 (USD 0.30) and takes only 5 minutes for application and interpretation. It can be used with significant confidence in smaller lesions (T-I and T-II) as an alternative to frozen sections in developing countries where facilities are unavailable. Its use in larger lesions (T-III and TIV) remains the topic of controversy and awaits a multi centre trial with a larger cohort

Effects of different acetylsalicylic acid doses on body organs, histopathology, and serum biochemical parameters in broiler birds

A indústria avícola é afetada por diversas doenças ou estresses. Particularmente devido às aves serem antipiréticas. O ácido acetilsalicílico (AAS) é largamente utilizado com diferentes objetivos que incluem o controle do estresse calórico, bem como a atividade respiratória e digestiva. O propósito deste estudo foi a avaliação dos efeitos benéficos e tóxicos do emprego de diferentes dosagens do AAS em frangos de corte. As variáveis analisadas foram: exame físico, parâmetros bioquímicos, bem como as alterações histopatológicas em seções de tecidos colhidas das aves em um ensaio experimental. O estudo foi conduzido em 60 frangos de corte com um dia de idade adquiridos em um mercado local de Faisalabad que foram recriados nos primeiros 14 dias em idênticas condições. Então no 15º dia as aves foram distribuídas randomicamente em quatro grupos identificados pelos números 1 a 4, com 15 aves em cada grupo. O grupo 4 foi mantido como grupo controle e os grupos 1, 2 e 3 foram tratados com AAS, respectivamente, nas doses de 300, 600 e 1200 mg/L de água de bebida, durante 21 dias. Foram realizadas três amostragens nos dias 21, 28 e 35 pós-tratamento. O peso vivo corpóreo e da carcaça foi registrado em cada amostragem. Em todos os órgãos viscerais foi analisada a presença de alterações patológicas. As amostras de soro sanguíneo foram colhidas para a avaliação bioquímica. O exame histopatológico de todos os órgãos viscerais foi realizado para a observação de alterações microscópicas. A partir da segunda amostragem foi observado um aumento significante (p<0,05) no peso corpóreo na dosagem de 300mg/L. Um significante aumento no peso relativo dos órgãos foi registrado na dosagem de 1200 mg/L. Os grupos tratados com dosagens de 600 e 1200 mg/L de AAS, apresentaram aumento significante dos níveis de AST, ALT e de creatinina quando comparados ao grupo controle. O grupo tratado com 1200 mg/L de AAS apresentou um aumento significante (P,0,05) de uréia, proteína sérica total e de albumina em todas as amostragens. No grupo de alta dosagem foram observados alterações histopatológicas constituídas por aumento dos hepatócitos, aumento dos espaços sinusoidais no fígado, congestão e anormalidades nos espaços glomerulares nos rins, congestão e ruptura alveolar nos pulmões, degeneração das vilosidades e celular nos intestinos A conclusão obtida foi que em frangos de corte uma baixa dosagem do AAS pode ser utilizada por um período de longa duração, apresentando um efeito promotor do crescimento, contudo as doses elevadas determinam toxicidade hepática e renal.The poultry industry suffers from various diseases or stresses. In poultry, apart from being antipyretic, acetylsalicylic acid (ASA) is widely used to cope with different issues including heat stress, and respiratory and digestive orders. This study evaluated the beneficial and toxic effects of ASA at different dose levels in broiler birds. To evaluate these toxic and beneficial effects it is necessary to examine the physical and serum biochemical parameters as well as the histopathological changes with tissue sections taken from broiler birds under experimental trial. This study was conducted on 60 one-day-old broiler chicks purchased from a local market in Faisalabad. Chicks were reared for the first 14 days under similar conditions. On the 15th day, birds were randomly divided into 4 groups (1-4) with 15 birds in each group. Group 4 was kept as control, while groups 1, 2, and 3 were treated with ASA at the dose of 300, 600, and 1200 mg/L of drinking water for 21 days. There were 3 samplings performed at 21, 28, and 35 days post-treatment. The live body weight and carcass weight were noted on each sampling. All the visceral organs were recorded for gross pathological changes. The serum samples were collected for biochemical evaluation. Histopathology of all the visceral organs was performed to observe the microscopic changes. A significant (P<0.05) increase in live body weight at a 300mg/L dose was noted after the first 2 samplings. A significant (P<0.05) increase in the relative organ weight was recorded at 1200 mg/L. The groups treated with ASA 600 and 1200 mg/L showed increased (P<0.05) AST, ALT, and creatinine levels from that of the control group. The group treated with 1200 mg/L of ASA showed increased (P<0.05) urea, serum total protein, and albumin level in all the samplings. Histopathological changes revealed swollen hepatocytes, increased sinusoidal spaces in the liver, congestion and abnormal glomerular spaces in the kidney, congestion and alveolar disruption in the lungs, and generation of villi and cellular degeneration in the intestine in a high-dose group. The study concluded that ASA at a low dose can be used for a long time in broilers and has a growth promontory role, while high-level doses cause hepatorenal toxicity

Age, Disease Severity and Ethnicity Influence Humoral Responses in a Multi-Ethnic COVID-19 Cohort

The COVID-19 pandemic has affected all individuals across the globe in some way. Despite large numbers of reported seroprevalence studies, there remains a limited understanding of how the magnitude and epitope utilization of the humoral immune response to SARS-CoV-2 viral anti-gens varies within populations following natural infection. Here, we designed a quantitative, multi-epitope protein microarray comprising various nucleocapsid protein structural motifs, including two structural domains and three intrinsically disordered regions. Quantitative data from the microarray provided complete differentiation between cases and pre-pandemic controls (100% sensitivity and specificity) in a case-control cohort (n = 100). We then assessed the influence of disease severity, age, and ethnicity on the strength and breadth of the humoral response in a multi-ethnic cohort (n = 138). As expected, patients with severe disease showed significantly higher antibody titers and interestingly also had significantly broader epitope coverage. A significant increase in antibody titer and epitope coverage was observed with increasing age, in both mild and severe disease, which is promising for vaccine efficacy in older individuals. Additionally, we observed significant differences in the breadth and strength of the humoral immune response in relation to ethnicity, which may reflect differences in genetic and lifestyle factors. Furthermore, our data enabled localization of the immuno-dominant epitope to the C-terminal structural domain of the viral nucleocapsid protein in two independent cohorts. Overall, we have designed, validated, and tested an advanced serological assay that enables accurate quantitation of the humoral response post natural infection and that has revealed unexpected differences in the magnitude and epitope utilization within a population

A comparative analysis of toluidine blue with frozen section in oral squamous cell carcinoma

Background:Surgical excision of the primary tumor with safe margins remains the mainstay of treatment for oral cavity squamous cell carcinoma (OSCC). The standard of care for assessment of intraoperative margins is frozen section histopathology. Unfortunately the facility is not available at most centers in limited resource countries. Toluidine blue, a metachromatic dye, has been well described in clinical identification of malignant and premalignant lesion in the oral cavity. Considering this we decided to explore intraoperative use of toluidine blue staining, in comparison with frozen sections, for the assessment of tumor-free margins. Methods: After obtaining clearance from the in-house ethical review committee, a prospective study was conducted at Aga Khan University Hospital, Karachi, from August 15, 2009 to March 14, 2010. A sample of 56 consenting Patients with biopsy-proven OSCC were included in the study, giving us 280 tumor margins. Margins were analyzed using toluidine blue staining and frozen section histopathology. A receiver operator curve (ROC) was then applied to compare assessment of margin status by toluidine blue and frozen section. Results: Of the 280 examined margins 11 stained positive with toluidine blue, three were positive on frozen section biopsy, and three were positive on final histopathology. Toluidine blue staining had sensitivity and specificity of 100% and 97%, respectively. The diagnostic accuracy of toluidine blue was found to be 97.1% with a positive predictive value (PPV) of 27.2% and a negative predictive value (NPV) of 100%. Conclusions: Toluidine blue can be used as an effective screening modality for the assessment of intraoperative margins in resource limited environments and reducing the number of frozen section biopsies performed. Further by providing real-time clinical information within minutes it can reduce indirect costs such as operating room time. It may also be used as an ad hoc for frozen section biopsies where frozen section facilities are available