Event-Driven Robust Geometric Control for a Nano Unmanned Helicopter

This work presents the design of an event-driven position tracking control law for a nano unmanned helicopter with a body length less than 25 centimeters and a mass less than 70 grams. A robust geometric controller based on robust integral sign error (RISE) is devised to compensate for the unmanned helicopter’s modeling uncertainties as well as unknown external disturbances. An event-driven robust nonlinear control technique is formulated for the nano helicopter’s position loop control taking into account the very limited onboard computing resources of the nano unmanned helicopter. The stability of the helicopter’s closed-loop system is analyzed. And practical flying experiments are performed to verify the efficiency of the control method. The experimental results demonstrate that not only the tracking accuracy is guaranteed, but also the proposed control method can also successfully reduce the consumption of the onboard flight control unit’s computing resources. Note to Practitioners—The motivation for this paper stems from the need to develop a control algorithm with low computational resource consumption that is suitable for nano unmanned helicopters. Due to the unique structure of nano unmanned helicopters, existing control algorithms designed for quadrotor drones cannot be directly applied to nano unmanned helicopters. Additionally, the small size and limited payload capacity of nano unmanned helicopters further restrict their available onboard computational resources. To address this issue, we propose an event-driven robust controller that can ensure tracking accuracy and reduce the use of computational resources.