Analysis of Control Strategies for Autonomous Motorcycles Stabilization and Trajectories Tracking

Abstract

Autonomous vehicles—defined as vehicles with carrying capacity of persons or property without the use of a human driver—are an interesting and recent problem, with increasing studies in the last 20 years. Regarding this type of vehicles, a less explored option is the motorcycle: apart from the difficulties inherent in making a vehicle move independently, autonomous motorcycles have to be able to remain stable at any speed and trajectory. This work’s main object of study is a small-scale electric motorcycle; represented by a linear model through a multibody approach: its four rigid bodies—wheels, chassis, handlebar and fork—have separately a characteristic behavior and together they influence the dynamics of each other. This approach results in lower order models, easier to simulate and to apply classical or modern control strategies. The two-wheeled vehicle is considered an inverted pendulum with a mobile base and other simplifications are proposed, as constant displacement speed or small steering and yaw angles. Since this vehicle is naturally unstable, to ensure a follow-up course without overturning it is necessary to apply an adjusted control signal; once the autonomous system studied will not have the presence of a mechanical counterbalance, there remains only the steering as a control strategy. Thus, this work analyzes the dynamic characteristics of the zero track vehicles and verifies the validity of different stability and path tracking control strategies of a motorcycle using as input only the steering of the handlebar.