A minimalist control strategy for small UAVs

Abstract

Abstract-Most autopilots of existing Miniature Unmanned Air Vehicles (MUAVs) rely on control architectures that typically use a large number of sensors (gyros, accelerometers, magnetometers, GPS) and a computationally demanding estimation of flight states. As a consequence, they tend to be complex, require a significant amount of processing power and are usually expensive. Many research projects that aim at experiments with one, or even several, MUAVs would benefit from a simpler, potentially smaller, lighter and less expensive autopilot for their flying platforms.In this paper, we present a minimalist control strategy for fixed-wing MUAVs that provides the three basic functionalities of airspeed, altitude and heading turnrate control while only using two pressure sensors and a single-axis rate gyro. To achieve this, we use reactive control loops, which rely on direct feedback from the sensors instead of full state information. In order to characterize the control strategy, it was implemented on a custom-made autopilot. With data recorded during flight experiments, we carried out a statistical analysis of step responses to altitude and turnrate commands as well as responses to artificial perturbations.

Beat-Based Synchronization and Steering for Groups of Fixed-Wing Flying Robots

“…Each robot is equipped with an autopilot for the control of altitude, airspeed and turn rate that provides an interface for receiving commands from a navigation controller. Embedded in the autopilot is a micro-controller that runs a minimalist control strategy based on input from only 3 sensors: one gyroscope and two pressure sensors [7]. …”

“…This work is inspired from the idea of emergent synchronization studied in nature [11] and the discovery of synchronized controllers for flying robots using artificial evolution [6]. We consider robots that fly at constant speed and rely on a heading sensor and a low-level autopilot that is able to regulate turn rate with some precision [7]. Based on these assumptions, we propose a minimal controller for flying robots where synchronization emerges from interactions between each robot and rhythmic beats sent using a radio-emitter from a base station on the ground or one of the robots.…”

Novel Dihedral-Based Control of Flapping-Wing Aircraft With Application to Perching

“…A similar approach for controlling turning flight of MAVs, where the turn rate is mapped to the corresponding yaw rate for the purpose of feedback and control, was used in [19]. Thus, we get…”

Underwater Robot Swarms: Challenges and Opportunities

“…The use of low-cost infrared sensors for attitude estimation is described by Brisset et al (2006) in the frame of the "Paparazzi" project, a very popular and simple open-source autopilot implementation. A minimalist control solution has been developed by Leven et al (2009), which provides an easy-to-use interface to the three basic functionalities of airspeed, altitude and turn-rate control for a fixed-wing platform while only relying on a minimum of sensors and reactive control loops. Reactive flight stabilisation has further been achieved with bio-inspired techniques like optic flow: attitude, altitude and turn control using the optic flow measured by several small on-board cameras have been shown for indoor (Zufferey et al, 2006b) and outdoor Zufferey et al, 2010) operation.…”