Delay-aware Robust Control for Safe Autonomous Driving

TL;DR

This paper introduces a unified delay-aware control framework for autonomous vehicles that models actuation delays, employs robust predictive control, and uses an adaptive Kalman filter to enhance safety and responsiveness.

Contribution

It presents a novel integrated approach combining actuation modeling, robust control, and adaptive filtering to handle delays in autonomous driving systems.

Findings

Framework effectively manages delays in high-speed scenarios.

Controller maintains safety without excessive conservativeness.

Applicable as both standalone and safety guard for high-level controllers.

Abstract

With the advancement of affordable self-driving vehicles using complicated nonlinear optimization but limited computation resources, computation time becomes a matter of concern. Other factors such as actuator dynamics and actuator command processing cost also unavoidably cause delays. In high-speed scenarios, these delays are critical to the safety of a vehicle. Recent works consider these delays individually, but none unifies them all in the context of autonomous driving. Moreover, recent works inappropriately consider computation time as a constant or a large upper bound, which makes the control either less responsive or over-conservative. To deal with all these delays, we present a unified framework by 1) modeling actuation dynamics, 2) using robust tube model predictive control, 3) using a novel adaptive Kalman filter without assuminga known process model and noise covariance, which makes the controller safe while minimizing conservativeness. On onehand, our approach can serve as a standalone controller; on theother hand, our approach provides a safety guard for a high-level controller, which assumes no delay. This can be used for compensating the sim-to-real gap when deploying a black-box learning-enabled controller trained in a simplistic environment without considering delays for practical vehicle systems.