Robust stabilization of UAV-manipulator systems using a passivity-based approach

Abstract

Abstract

Abstract Unmanned aerial vehicle-manipulator systems (UAVMs) meet the growing demand for diverse tasks in complex unstructured environments, and have emerged as a key research hotspot in robotics and control. To enable stable operation under uncertain conditions, a novel passivity-based integrated control strategy is proposed for UAVMs in this work, achieving stable flight and precise operation in unknown dynamic environments via unified control of UAV position, attitude, and manipulator joint angles. First, a unified fully-coupled nonlinear dynamic model for rotor UAVs carrying a two-joint manipulator is established based on Euler-Lagrange equations, fully incorporating the internal nonlinear coupling between the UAV body and manipulator linkages. Next, strict output passivity of the closed-loop system is derived via energy analysis, and a damping-injection passivity-based controller is developed without requiring accurate full-model prior or measurement knowledge. The global asymptotic stability of the closed-loop system is then strictly proven with a constructed Lyapunov function. It overcomes the stability limitations of traditional benchmark under unknown disturbances and model uncertainties, and balances theoretical rigor, simplicity and anti-disturbance robustness. Finally, comparative simulations against the conventional Proportional-Integral-Derivative (PID) controller are conducted to validate its performance. Results show the proposed strategy outperforms both Linear Quadratic Regulator (LQR) and PID in tracking accuracy, anti-interference capability and robustness, especially in suppressing internal coupling disturbances from manipulator motion, with near-zero steady-state error and zero overshoot. These results confirm its effectiveness and application potential for UAVMs in unknown dynamic environments.