What is the relationship between angular velocity and power efficiency of a twin blanded single rotor helicopter system, in hover?
A traditional helicopter requires 60 - 80% more power to hover than when in forward or lateral flight, making the manoeuvre extremely power inefficient. To maximise efficiency, industrially many properties of the helicopter and rotor have been changed and tested, for example: optimising blade shape, fuselage shape and changing weights of different helicopter components. This report in particular aims to find a relationship between power efficiency and angular velocity for a twin bladed hovering helicopter with a single rotor. The angular velocity of a blade measures the frequency of its revolution about a fixed point. A theoretical approach was first taken and then justified with empirical data. Firstly, a model for power efficiency was derived with William Froude’s momentum and blade element theory. The efficiency equations incorporated the thrust and power coefficients. Therefore, the research focused on determining values for these coefficients by manipulating equations, using industrial specifications and simulations from the XFOIL software. In order to validate the accuracy for such theoretically generated data, an experiment was conducted for a comparison. The theoretical and empirical data were concurrent, as they followed a similar trend and the empirical values overlapped within the theoretical error bars. The power efficiency for different angular velocities were then found by substituting values for the coefficients. The results demonstrated a positive relationship; where, as angular velocity increases, power efficiency increases too, then plateaus and repeats the same trend once again. The research raises many questions and could be extended by determining if a similar relationship exists for tri-copters and quadcopters.
Utilizing Computer Vision And Machine Learning Algorithms To Control Smart Systems Helping Physically Disabled People.
About 15% of the world's population lives with some form of disability, of whom 2-4% experience significant difficulties in functioning. The global disability prevalence is higher than previous WHO estimates, which date from the 1970s and suggested a figure of around 10%. This global estimate for disability is on the rise due to population ageing and the rapid spread of chronic diseases, as well as improvements in the methodologies used to measure disability. This research deals specifically with the physically disabled and often people with physical disabilities feel frustrated because they cannot do activities such as: playing sports and doing exercise. Having a physical disability also changes the way a person lives their life. They may find their life changes and activities they had previously included as part of their daily routine such as brushing their teeth, washing and doing household chores suddenly become a huge effort and many people require another person's help to carry out these activities. Also, they suffer from three basic challenges like; education, economic and, communication. Firstly, Education: The results of the investigation revealed that the physically handicapped. They face a lot of problems while studying they can't learn as the normal ones and they needs someone to help in learning. Secondly, Economic: they can't work and achieve income to help in his practical life. And finally Communication: they can't communicate with others because of his disability.
Development of a neurointerface glove with tactile feedback
Research Question or Engineering Problem A stroke continues to be the most important medical and social problem of the modern world. Stroke is a type of acute cerebrovascular accident (ACVA) and is characterised by a sudden (within minutes, less often - hours) appearance of focal neurological symptoms (motor, speech, sensory, coordinating, visual and other disorders) and / or general brain disorders (depression of consciousness, headache, vomiting, etc.) that persist for more than 24 hours or lead to death of the patient in a short period of time due to a cause of cerebrovascular origin. There are two clinical and pathogenetic forms of stroke: ishemic stroke (cerebral infarction) is caused by acute focal cerebral ischemia, leading to infarction (zone of ischemic necrosis) of the brain; hemorrhagic stroke (non-traumatic intracerebral hemorrhage) is caused by rupture of an intracerebral vessel and blood penetration into the brain parenchyma or rupture of an arterial aneurysm with subarachnoid hemorrhage (SAH). ACVA also includes transient disorders of cerebral circulation, characterised by the sudden occurrence of focal neurological symptoms that develop in a patient with cardiovascular disease (arterial hypertension, atherosclerosis, atrial fibrillation, vasculitis, etc.), last for several minutes, less often hours, but no more than 24 hours, and ends with a full restoration of the impaired brain functions. Transient disorders of cerebral circulation include: transient ischemic attack (TIA), which develops as a result of short-term local cerebral ischemia and is characterised by sudden transient neurological disorders with focal symptoms; hypertensive cerebral emergency, which is a condition associated with an acute (usually significant) rise in blood pressure (BP) and accompanied by the appearance of general cerebral (less often focal) neurological symptoms secondary to hypertension. The most severe form of hypertensive crisis is acute hypertensive encephalopathy, the basis of pathogenesis of which is cerebral edema. Cerebral infarction generally is the result of the interaction of many etiopathogenetic factors, which can be subdivided into local and systemic ones. Local factors include: morphological changes in the brachiocephalic or intracerebral arteries (pathological tortuosity, etc.), atherosclerotic lesions of the vessels of the aortic arch and cerebral arteries, cardiac lesions as a source of thromboembolic cerebral infarctions, fibromuscular dysplasias of the walls of the brachiocephalic and cerebral arteries, brachiocephalic artery dissection, vasculitis (arteritis), changes in the cervical spine with the formation of extravasal compression of the vertebral arteries, anomalies in the structure of the vessels of the neck and brain (hypoplasia of the vertebral artery, trifurcation of the internal carotid artery), etc. Systemic factors include: disorders of central and cerebral hemodynamics (a sharp change in BP or a decrease in cardiac output, etc.), hereditary and acquired coagulopathies, polycythemia, certain forms of leukemia, hypovolemia, psychoemotional stress / distress, etc., hypercoagulative / hyperaggregatory side effects of a number of medications (oral contraceptives, etc.). In the 俄羅斯n Federation, more than 500 thousand people have a stroke every year. About 25,000 new cases of stroke occur in St. Petersburg every year. The incidence of stroke in the 俄羅斯n Federation is 3.48 ± 0.21 cases per 1000 people. The incidence of various types of ACVA varies widely, in particular, cerebral infarctions account for 65–75%, hemorrhages (including subarachnoid hemorrhages) – 15–20%, transient cerebral circulation disorders account for 10–15%. The frequency of cerebral strokes in the population over 50–55 years old increases by 1.8–2 times in each subsequent decade of life. Medical and socio-economic consequences of ACVA are very significant, in particular, death in the acute period of stroke occurs in 34.6% cases, during the first year after the end of the acute period in 13.4% cases; severe disability with the need for constant care is present in 20.0% of stroke patients; 56.0% have limited working capacity and only 8.0% return to their previous work activity. Disability due to stroke (the national average is 56–81%) in our country ranks first among all causes of primary disability, amounting to 3.2 per 10 thousand people. Stroke mortality among working-age population has increased in the 俄羅斯n Federation by more than 30% over the past 10 years. The annual death rate from stroke in our country is 175 per 100 thousand people. Stroke annually becomes the main cause of disability: 85% of victims experience a decrease in strength or a complete lack of ability to control the muscles of half of the body and only half of them recover limb functions partially or completely; the rest of those who have suffered a stroke remain paralysed and require care, since they are not able to completely independent existence. In this regard, recently, in the process of rehabilitation, the technology of brain-computer interfaces (BCI) has begun to be actively used. on the basis of this technology exercise machines are created. These exercise machines are controlled directly by the patient himself. This feature of the technology increases the effect of the procedure by providing a direct connection between the patient's desire and effort with the work of the simulator. The greatest development of this technology is observed in the field of medicine, where BCIs are used as a means of communication or as one of the tools of neurorehabilitation. In this regard, it seems very promising to develop the most optimal brain-computer interfaces. The goal of our project was to create an automated training complex in the form of a neuro-controlled glove with tactile feedback, designed to simplify access to rehabilitation means.