Truly Force-based Control of a UAV

One of the main limitations of aerial vehicles given by the imprecision of the actuators. It is well known that the thrust produced by a propeller depends on the spinning velocity of the motor and some aerodynamic coefficients depending on the propeller and other environmental factors. To have a more precise control of at least the spinning rate of the motor, a closed-loop Electronic Speed Controller (ESC) should be integrated and tested. However, this solves the problem only partially: aerodynamic uncertainty and disturbances will make the generated thrust uncertain as well. A novel solution is to install a force/torque sensor between the motor and the main frame of the vehicle. This sensor has the potential to precisely measure the thrust produced by the motor. In a previous project, we managed to have a first single propeller unit controlled in thrust. In this project we would like to go further integrating this solution on a real multi-rotors (quadrotor and hexacopter), now truly force-based controlled. This will require the design and development of a quadrotor integrating such new actuation units and modify the current control and signal processing architecture to have a first truly force-based controlled UAV. Further iterations of tuning & testing will be required to improve performance.