Control of Hovering Altitude of a Quadrotor with Shifted Centre of Gravity for Inspection of High-Rise Structures

Abstract

Abstract-Unmanned aerial vehicles are specialized robots. Recently they were used in many civil applications such as patrolling, firefighting, rescuing tasks and being the shadow cinematographer in many movie-making companies. The new developments in material technology led to new sophisticated, miniature range of sensors and actuators, which are able to substitute gyroscopes and accelerometers. In light of this, new miniature aerial vehicles appeared in the market. Micro-UAV (MUAV) is able to infiltrate sites, where the bigger aerial robots could not. It is more maneuverable and recently is becoming able to fly to new altitudes. This allow the MUAV to be used for site scanning, to perform or assist in photogrammetry procedures in light to create 3D building models and maps. The future of the MUAV seems to be existing: In relation to medical field, the aerial robot is being used to perform radiation leakage test that, is done manually in most of the hospitals. It is also planned to be used to deliver lightweight goods within the city.The versatility and adaptability of the miniature aerial robot creates new requirements for stability, maneuverability and speed. In this paper, we offer to study the quadrotor while inspecting high-rise structures using simulations. As the quadrotor is vertical take-off and landing vehicle, it is very important to analyze the effect of the altitude on the stability of in order to create control algorithm able to maintain the necessary hovering position of the quadrotor. A better stabilization leads to better scanning results and high quality captured images.

Inspection of Flyover Bridges Using Quadrotor

“…The simulation results are obtained taking into consideration the factor of shifted centre of gravity in all the control loops. It is very important to calculate the moment of inertia according to the centre of gravity for a free-rotating object around the altitude axis [19,23]. Ignoring this factor can produce supplementary acceleration and moments on the axis of the gyroscope, which have to be compensated by the control system.…”

“…For instance, [11,15,19] simulated autonomous quadrotor inspection for high-rise structures. In a related matter, unmanned quadrotors are more frequently "supervised" [14,16,17].…”

“…Besides that, we will consider the fact of shifted centre of gravity in all the control loops. This factor was proven to be essential to simulate flights and design reliable controllers [3,19] The quadrotor dynamics can be represented as follows:…”

“…Driven by the development in power electronics, MEMS and NEMS actuators and sensors and microcontrollers, quadrotors became more energy efficient, more stable. The low-cost, sufficient payload and flight endurance to carry out inspection missions [11,13,15,18,19] can recommend the integration of the quadrotor in performing bridges inspections. Hence the aim of this paper is to use autonomous quadrotor to inspect flyover bridges interconnecting multiple cities and locations as part of periodic preventive maintenance (Figure 2).…”