Steady-State Drifting Equilibrium Analysis of Single-Track Two-Wheeled Robots for Controller Design
Feilong Jing, Yang Deng, Boyi Wang, Xudong Zheng, Yifan Sun, Zhang Chen, Bin Liang
TL;DR
This work extends drifting concepts to single-track two-wheeled robots by deriving a Newton-Euler-based model that accommodates large sideslip and wheel-ground constraints. It introduces ADESA, an analytical drifting-equilibrium solver, alongside a numerical method, to rapidly compute equilibria and reveal drift mechanisms, including counter-steering. Building on these equilibria, the authors design an MPC-based drifting controller and a transition controller that leverages ADESA for fast warm-starts, validated in MuJoCo simulations across varying conditions. The results demonstrate accurate equilibrium prediction, robust drifting control, and feasible equilibrium transitions, highlighting practical potential for enhanced maneuverability and safety in STTW platforms.
Abstract
Drifting is an advanced driving technique where the wheeled robot's tire-ground interaction breaks the common non-holonomic pure rolling constraint. This allows high-maneuverability tasks like quick cornering, and steady-state drifting control enhances motion stability under lateral slip conditions. While drifting has been successfully achieved in four-wheeled robot systems, its application to single-track two-wheeled (STTW) robots, such as unmanned motorcycles or bicycles, has not been thoroughly studied. To bridge this gap, this paper extends the drifting equilibrium theory to STTW robots and reveals the mechanism behind the steady-state drifting maneuver. Notably, the counter-steering drifting technique used by skilled motorcyclists is explained through this theory. In addition, an analytical algorithm based on intrinsic geometry and kinematics relationships is proposed, reducing the computation time by four orders of magnitude while maintaining less than 6% error compared to numerical methods. Based on equilibrium analysis, a model predictive controller (MPC) is designed to achieve steady-state drifting and equilibrium points transition, with its effectiveness and robustness validated through simulations.
