Autonomous flight in unstructured and unknown indoor environments

Abstract

This paper presents our solution for enabling a quadrotor helicopter, equipped with a laser rangefinder sensor, to autonomously explore and map unstructured and unknown indoor environments. While these capabilities are already commodities on ground vehicles, air vehicles seeking the same performance face unique challenges. In this paper, we describe the difficulties in achieving fully autonomous helicopter flight, highlighting the differences between ground and helicopter robots that make it difficult to use algorithms developed for ground robots. We then describe our solutions to the key problems, including a multi-level sensing and control hierarchy, a high-speed laser scan-matching algorithm, EKF data fusion, and a high-level SLAM implementation. Finally, we show experimental results that illustrate the helicopter’s ability to navigate accurately and autonomously in unknown environments. Figure 1: Our quadrotor helicopter. Sensing and computation components include a Hokuyo Laser Rangefinder (1), laserdeflecting mirrors for altitude (2), a monocular camera (3), an IMU (4), a Gumstix processor (5), and the helicopter’s internal processor (6) 1