Low cost X4 platform to study control algorithms

In this paper, we present the design of an autopilot embedded system applied to control a four rotor mini helicopter, called X4-flyer. The main goal is to achieve a stable flight, controlling the vehicle attitude; this is done using two control strategies: a linear PD control and nonlinear nested saturations control. The onboard system uses a simplified architecture and the main processor has a structured program to handle the data acquisition, and calculates the control to send actuators correction to get a desired set point. Real time experiments, in a pivoted platform, show that the autopilot is a reliable low cost platform.