Flying a Quadrotor with Unknown Actuators and Sensor Configuration

TL;DR

This paper presents a method for rapid estimation of quadrotor parameters, including IMU position and motor thrust directions, enabling quick calibration after minimal throws, thus simplifying UAV configuration.

Contribution

It extends previous work by incorporating IMU and motor parameter estimation using minimal throws, facilitating faster and more accurate UAV setup.

Findings

Successful IMU and motor parameter estimation after low-altitude throws

Effective recovery to stable hover post-parameter estimation

Applicability demonstrated on fully-actuated UAV models

Abstract

Though control algorithms for multirotor Unmanned Air Vehicle (UAV) are well understood, the configuration, parameter estimation, and tuning of flight control algorithms takes quite some time and resources. In previous work, we have shown that it is possible to identify the control effectiveness and motor dynamics of a multirotor fast enough for it to recover to a stable hover after being thrown 4 meters in the air. In this paper, we extend this to include estimation of the position of the Inertial Measurement Unit (IMU) relative to the Center of Gravity (CoG), estimation of the IMU rotation, the thrust direction of all motors and the optimal combined thrust direction. In order to guarantee a correct IMU position estimation, two prior throw-and-catches of the vehicle with spin around different axes are required. For these throws, a height as low as 1 meter is sufficient. Quadrotor flight experimentation confirms the efficacy of the approach, and a simulation shows its applicability to fully-actuated crafts with multiple possible hover orientations.