Low Speed Control of an Autonomous Vehicle Using a Hybrid Fractional Order Controller

TL;DR

This paper develops a hybrid fractional order control strategy for low-speed autonomous vehicle navigation, improving safety and robustness in congested traffic by controlling throttle and brake with fractional PI controllers.

Contribution

It introduces an improved hybrid fractional order control method tailored for low-speed autonomous driving, considering hybrid vehicle dynamics and uncertain brake system behavior.

Findings

Effective control of vehicle speed at low speeds demonstrated through experiments.

Robustness of the control system against system uncertainties validated.

Hybrid fractional order controllers outperform traditional methods in safety and precision.

Abstract

Highly non-linear vehicle dynamics plays an important role in autonomous driving systems, especially in congested traffic situations at very low speeds. Due to this fact, accurate controllers are needed in order to ensure safety during navigation. In this paper, based on a previous fractional order speed control, an improved fractional order control is presented to control a commercial Citro\"en C3 prototype -which has automatic driving capabilities- at low speeds, which considers a hybrid model of the vehicle. Specifically, two different fractional order PI{\alpha} controllers are designed to act over the throttle and brake pedals, respectively. Concerning to the uncertain dynamics of the system during the brake action parameters are tuned to design a robust controller. In addition, the system is modeled as hybrid fractional order differential inclusions. Experimental and simulation results, obtained in a real circuit, are given to demonstrate the effectiveness of the proposed strategies for cruise control at low speeds.