Thrust Control for Multirotor Aerial Vehicles

Abstract

This paper presents a novel control algorithm to regulate the aerodynamic thrust produced by fixed-pitch rotors commonly used on small-scale electrically powered multirotor aerial vehicles. The proposed controller significantly improves on the disturbance rejection and gust tolerance of rotor thrust control compared to state-of-the-art RPM (revolutions per minute) rotor control schemes. The thrust modelling approach taken is based on a model of aerodynamic power generated by a fixedpitch rotor and computed in real-time on the embedded electronic speed controllers using measurements of electrical power and rotor angular velocity. Static and dynamic flight tests were carried out in downdrafts and updrafts of varying strengths to quantify the resulting improvement in maintaining a desired thrust setpoint. The performance of the proposed approach in flight conditions is demonstrated by a path tracking experiment where a quadrotor was flown through an artificial wind gust and the trajectory tracking error was measured. The proposed approach for thrust control demonstrably reduced tracking error compared to classical RPM rotor control.

Differential Flatness of Quadrotor Dynamics Subject to Rotor Drag for Accurate Tracking of High-Speed Trajectories

“…In [9], the authors achieve accurate thrust control by electronic speed controllers through a model of the aerodynamic power generated by a fixed-pitch rotor under wind disturbances, which reduces the trajectory tracking error of a quadrotor. Rotor drag was also considered in control methods for multi-rotor vehicles in [10] and [11], where the control problem was simplified by decomposing the rotor drag force into a component that is independent of the vehicle's orientation and one along the thrust direction, which leads to an explicit expression for the desired thrust direction.…”

Optimal 3D-Trajectory Design and Resource Allocation for Solar-Powered UAV Communication Systems

“…as the velocity of the UAV during the n-th time slot, where v [31], [32]. In particular, the induced power for level flight in time slot n is modeled as [31, Eq.…”

Supervisory Control of Multirotor Vehicles in Challenging Conditions Using Inertial Measurements

“…al. [26] used aerodynamic power [27] to estimate induced flow through the rotor, however, there is insufficient information with this approach to discriminate between motions in e 1 , e 2 and e 3 directions [28]. Davis and Pounds [29] used a force torque sensor to estimate total velocities of up to 1m/s with an accuracy of about 0.1m/s.…”