Execution-Times Measurement of an Embedded Real-Time Control System for Stationary Flight in a Quadrotor-Type UAV

This work presents the real-time simulation carried out on the Raspberry Pi 2 model B® embedded computer (EC) of the kinematic model of a quadrotor-type Unmanned Aerial Vehicle (UAV) and its control system for steady-state flight. The simulated quadrotor's mathematical model has been carried out according to Euler-Lagrange formalism, obtaining a deterministic, non-linear, and unstable model which describes the translation and orientation kinematics of the UAV. To achieve the design of the aircraft control system, the non-linear model has been linearized, concretizing a linear model expressed in state space. Considering this linear model, four proportional-integral-derivative (PID) controllers have been tuned using the root locus technique in the continuous time domain. These controllers work together, thus forming the control system for the quadrotor's stationary flight. To manipulate the aircraft's orientation, three of the mentioned PID controllers are used; for elevation, the PID remaining controller is used. To perform the real-time embedded simulation, five real-time tasks (RTT) have been programmed: one dedicated to the simulation of the aircraft kinematics and four dedicated to the simulation of the control system.