A Novel Overactuated Quadrotor Unmanned Aerial Vehicle: Modeling, Control, and Experimental Validation

Abstract

Standard quadrotor unmanned aerial vehicles (UAVs) possess a limited mobility because of their inherent underactuation, that is, availability of four independent control inputs (the four propeller spinning velocities) versus the 6 degrees of freedom parameterizing the quadrotor position/orientation in space. Thus, the quadrotor pose cannot track arbitrary trajectories in space (e.g., it can hover on the spot only when horizontal). Because UAVs are more and more employed as service robots for interaction with the environment, this loss of mobility due to their underactuation can constitute a limiting factor. In this paper, we present a novel design for a quadrotor UAV with tilting propellers which is able to overcome these limitations. Indeed, the additional set of four control inputs actuating the propeller tilting angles is shown to yield full actuation to the quadrotor position/orientation in space, thus allowing it to behave as a fully actuated flying vehicle. We then develop a comprehensive modeling and control framework for the proposed quadrotor, and subsequently illustrate the hardware and software specifications of an experimental prototype. Finally, the results of several simulations and real experiments are reported to illustrate the capabilities of the proposed novel UAV design

Energetics in robotic flight at small scales

“…However, it appears that the reported cost functional does not fully exploit the overactuation feature of the employed vehicle. The vehicle is also found less energy-efficient in hovering compared with the traditional quadrotor configuration [60]. Still, appropriate shaping of the employed cost functional may yield improved energy efficiency in forward flight.…”

“…Another interesting approach adds servo motors to the tip of each arm of a quadrotor design to allow tilting of the vehicle's motors [60]. This gives rise to an overactuated system.…”

“…One idea is to formulate an optimal control problem to generate paths that minimize the energy consumed with respect to motor angular velocities and accelerations [61], or only motor angular velocities [60].…”

Chattering-Free Tracking Control of a Fully Actuated Multirotor with Passively Tilted Rotors

“…A novel overactuated quadrotor UAV based on actively tilted rotors proposed in [9] is able to overcome underactuation limitation. However, it requires additional motors, which makes the system more complex and also increases power consumption.…”

Design of Vectored Sum Defuzzification Based Fuzzy Logic System for Hovering Control of Quad-Copter

“…In [3], authors proposed how to decrease computational complexity with appropriate control performance for real time and online applications. Another paper [4] showed that the additional set of 4 control inputs actuating the propeller tilting angles yields full actuation to the quadrotor posi-tion/orientation in space and it allowed to behave as a fully-actuated flying vehicle.…”