Towards Low-Latency High-Bandwidth Control of Quadrotors using Event Cameras

TL;DR

This paper demonstrates the feasibility of low-latency, high-bandwidth attitude control of quadrotors using event cameras, achieving rapid response times and high rotational speeds through novel event-based state estimation and control methods.

Contribution

It introduces a novel event-based state estimation and control scheme for quadrotors, enabling high-speed attitude tracking with minimal latency.

Findings

State estimator operates at 1 kHz update rate

Latency of 12 ms achieved in control loop

Attitude tracking speeds over 1600 deg/s

Abstract

Event cameras are a promising candidate to enable high speed vision-based control due to their low sensor latency and high temporal resolution. However, purely event-based feedback has yet to be used in the control of drones. In this work, a first step towards implementing low-latency high-bandwidth control of quadrotors using event cameras is taken. In particular, this paper addresses the problem of one-dimensional attitude tracking using a dualcopter platform equipped with an event camera. The event-based state estimation consists of a modified Hough transform algorithm combined with a Kalman filter that outputs the roll angle and angular velocity of the dualcopter relative to a horizon marked by a black-and-white disk. The estimated state is processed by a proportional-derivative attitude control law that computes the rotor thrusts required to track the desired attitude. The proposed attitude tracking scheme shows promising results of event-camera-driven closed loop control: the state estimator performs with an update rate of 1 kHz and a latency determined to be 12 ms, enabling attitude tracking at speeds of over 1600 deg/s.