An Actuator Allocation Method for a Variable-Pitch Propeller System of Quadrotor-Based UAVs

Abstract

This paper presents a control allocation method for enhancing the attitude following performance and the energy efficiency of a variable-pitch propeller (VPP) system on quadrotor-based unmanned aerial vehicles. The VPP system was modeled according to the blade element momentum (BEM) theory, and an actuator allocation method was developed with the aim of enhancing the attitude control and energy performance. A simulation environment was built to validate the VPP system by creating a thrust and moment database from the experiments. A four-motor variable-pitch quadrotor was built for verifying the proposed method. The control allocation method was firstly verified in a simulation environment, and was then implemented in a flight controller for indoor flight experiments. The simulation results show the proposed control allocation method greatly improves the yaw following performance. The experimental results demonstrate a difference in the energy consumption through various pitch angles, as well as a reduction in energy consumption, by applying this VPP system.

The control method of a quadrotor driven by bidirectional electronic speed controllers

“…The network training is performed offline, which requires minimal computational resources. In [11], variable-pitch propellers are applied, thus an actuator allocation method is developed with the aim of enhancing the attitude control and energy performance. Work [12] adopts additional dynamics of the control allocation loop to ensure stability of the full system, which includes the outer or position control loop, the intermediate or attitude control loop, and the innermost or the control allocation loop.…”

“…The actuators, especially power components of a QUAV mainly include electronic speed controllers (ESCs), motors and blades, as the 1,2,3 in Figure 3 below respectively: To overcome the above defects, some work applies variable-pitch-blades, which achieve bidirectional thrust by means of adjusting the pitch angles of blades [15] [16]. It offers bidirectiona l thrust to adjust attitude and position rapidly, but the work requires complex controllers for variable pitch structures (to control pitch angles of blades in addition to speed), thus deteriorates the disadvantages of small payload and short endurance.…”

Robust attitude tracking control for a variable‐pitch quadrotor with uncertainties

“…The summary of their work can be found in Mark Cutler's Ph.D. thesis 6 . Similarly, authors in Reference 7 present a control allocation method for a variable‐pitch quadrotor to enhance the attitude control and energy performance. To evaluate the dynamic responses of variable‐pitch quadrotors in hover and forward flight, the effects of rotor inflow models are deeply investigated in Reference 8.…”