طراحي مفهومي و ساخت بالگرد بدون سرنشين

Conceptual Design and Construction of an Unmanned Helicopter

در اين مطالعه نسبت به طراحي و ساخت يك پهپاد كوچك عمود‌پرواز اقدام مي‌شود؛ هدف از ساخت چنين پرنده‌يي ساده‌سازي و بومي‌سازي اين دانش است. در طراحي اين بالگرد براي كم‌كردن قطعات و ساده‌كردن سازوكار ها، به‌خصوص سازوكار انتقال فرمان (سواشپليت) كه اهميت و پيچيدگي خاصي دارد، تلاش شده است. يكي از نوآوري‌هاي اصلي اين نوشتار تحليل سينماتيكي رفتار انتقال فرمان (سواشپليت) ملخ است، به‌گونه‌يي كه همراه با توضيح كاركرد سواشپليت، و لحاظ آن به‌شكل روبات موازي، معادلات سينماتيكي حاكم بر آن نوشته شده است. رسيدن به سقف پرواز ايستايي بالا از ديگر دستاوردهاي ساخت اين وسيله است كه دست‌يابي به آن طراح را مجاب كرد تا اين وسيله را در ارتفاعات قمصر كاشان به پرواز درآورد. اين بالگرد از توانايي حمل وزن 5/3 كيلوگرم در ارتفاع سطح دريا نيز برخوردار است كه با توجه به وزن كم پرنده بسيار حايز اهميت است. سيستم انتقال قدرت و ضد گشتاوري اين وسيله نيز با كمك ادوات ساده و قابل دسترس همانند چند چرخ دنده و شفت فولادي با قطر 2 ميلي‌متر ساخته شده و در‌مورد كاركرد آن‌ها توضيح داده شده است.

Over the past decade, developing an Unmanned Aerial Vehicles (UAV) design has stimulated the interest of many mechanical, aerospace, and electrical engineering researchers in an industrial context, and, due to their combined efforts with academia, there has been huge progress made in developing such a device. Due to several feature of UAVs, such as compact size, special flying capabilities and light maneuverability, they have widespread functional applications in civil and military applications. Construction of the promising design of a Mini Unmanned Helicopter requires investigation in an interdisciplinary context of aerospace and mechatronics, and a blend of necessary knowledge from both; a synergy hard to achieve, which is the central subject of this paper. Although a large number of helicopters have been made over the decades, despite their unique features including savings in cost and time, they still require more scientific research to fill general theoretical gaps. Considering the complex mechanical mechanisms in a Mini Unmanned Helicopter, besides a considerable increase in cost, a great deal of time is required to make it functional and effective. In this article, the design and construction of a mini unmanned helicopter is detailed. Building an efficient, inexpensive flying machine can be applicable to a wide range of applications, including, among others, freight purposes. In the proposed mini unmanned helicopter, some attempts were made to reduce the number of mechanical parts and simplify the involved mechanisms; in particular, the command transfer mechanism, known as the swashplate, which is of special significance and complexity. One of the main topics of this article is analysis of the swashplate as a mechanism. The so-called swashplate is made equivalent to a parallel mechanism, and kinematic properties are investigated accordingly. Reaching high altitude lift-off is another achievement of this device, which enabled the project to test its flying performance in a city at almost 8900 feet above sea level. This mini unmanned helicopter is capable of carrying a weight of 4 kg, at sea level altitude, which is of great significance with respect to helicopter weight. The anti-torque system and power transfer of this device is built with the aid of some available and simple mechanical tools, such as gears and steel shafts with a diameter of 2 mm.