1.1 Introduction
Quad rotor is a constant A.I. multiplied by the difference between the measured and desired position, be it lateral or angular position. An unmanned aerial vehicle (UAV) is an aircraft that does not carry a human operator. It is normally a powered aircraft that relies on aerodynamic forces to provide motion. This motion is controlled either by onboard computer (autonomous) or by remote control. Accurate methods of detecting and reacting to the UAVs environment are being developed; making some modern UAVs are virtually crash-proof (Merz & Kendoul 2013).
As a prelude to other parts of this study, this chapter will discuss the background upon which this study was initiated, the statement of problems that led to this study, the Aim and Objectives of the study. Others are Significance of the study, Scope of work, Research hypothesis and questions, Limitations of the Study and Definition of technical terms.
1.2 Background of Study
Quadrotors are symmetrical vehicles with four equally sized rotors at the end of four equal length rods. Early designs of quadrotors were completed in the 1920‟s by Etienne Omichen, Dr. George de Bothezat and Ivan Jerome. These designs, however, never truly grasped the attention of the public or the in case of Dr. Bothezat and Jerome the military.
The first iteration of the quad rotor used an inertial measurement unit consisting of MEMS gyroscopes and accelerometers and an infrared rangefinder for the Z distance measuring; all components were controlled by a Texas Instruments MSP430 on an Olimex development board. It was first thought that a math coprocessor would need to be used to handle floating-point arithmetic; however the MSP by itself was able to run the entire code 1000 times per second, which was more than fast enough for the quad rotor.
Quadrotors are a special form of rotorcraft UAV that use two pairs of contra- rotating rotors to provide lift and directional control (indexed by ‘North’, ‘South’, ‘East’ and ‘West’). Unlike conventional helicopters, quadrotors typically have fixed-pitch blades and vary their thrust by changing rotor speed. Flight attitude is regulated entirely by rotor speed. To tilt the helicopter, the speed of one motor is increased and the opposite motor decreased the difference in thrust causes the craft to pitch or roll.
As UAVs are becoming more advanced and more practical, with longer flight times and larger payloads, more tasks are being found that they can perform. From pleasure activities to advanced military versions, UAVs are finding a bigger role in the modern world (Merz & Kendoul 2013). There are two types of UAVs, rotary-wing, and fixed-wing. Fixed-wing UAVs are unmanned airplanes that use forward propulsion over a fixed airfoil to gain lift. They need a relatively high forward velocity in order to produce this lift and so are not suitable for operation in confined or hazardous environments. Rotary-wing UAVS can further be divided into another 2 types, single rotor, and multi-rotor. Single rotor vehicles are helicopters. They generally use a single large diameter rotor to generate lift and require a tail rotor for stability and direction control. Multi-rotor vehicles use multiple rotors to control all forms of motion (Kendoul 2012).
Therefore, in Nigeria where the research was carried out, the activities that was conducted is to design and construct a quad rotor capable of lifting from the floor.
1.3 Statement of Problems
Investigation revealed that the key enabling technologies required to build larger quadrotors: thrust generation, rotor speed control and attitude control. Solving the thrust problem demands specific focus on the design of compact rotors. Small custom-designed blades can take advantage of ideal chord and twist geometry, where structural limitations make this impractical for full-scale aircraft. However, the optimal airfoils for the low Reynold’s Number flow conditions en- countered by small quadrotors are very thin and it is difficult to manufacture such blades.
The aerodynamic torque on the blades will cause them to deform under load conditions which is a problem that is usually ignored in traditional helicopter systems, where the variable pitch mechanism is used to adjust blade twist. The design of high-performance rotors for small-scale UAVs is a trade-off between ease of manufacture, mechanical properties of the airfoil and optimal aerodynamic performance.
1.4 Aim and Objectives of Study
The aim of the study is to design and construct a quad rotor capable of lifting from the floor. In achieving this aim, the following specific objectives were laid out as follows:
- To design of a quadrotor capable of lifting from the ground.
- To optimize the frame design and weight reduction for the quadrotor.
- To configure the flight controller of the quadrotor and allow the quadrotor to hover at a given altitude.
- To choose an existing quadcopter kit, couple the kits, and configuring each of the kits on the choosing flight controller.
1.5 Significance of Study
This study will be of immense benefit to researchers who intend to know more on this study and can also be used by non-researchers to build more on their research work. This study contributes to knowledge and could serve as a guide for other study.
1.6 Scope of Study
The scope of the research is focused on the design and construction of a quad rotor capable of lifting from the floor.
1.7 Limitations of the Study
During the course of this study, many things militated against its completion, some of which are:
- Time Constraint: The time frame given to accomplish this project was very short due to school academic calendar and it was carried out under pressure which made the researcher not to implement some necessary features.
- Research material: availability of research material is a major setback to the scope of the study.
- Frequent power failure: This made the researcher append more money on fuel to ensure sustainable power.
- Financial Constraint: Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, literature or information and in the process of data collection.
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