Output-feedback cascaded VFO-ADR tracking controller for autonomous rigid-body vehicles moving in a 3D space

摘要

The paper presents a derivation of a cascaded control system for autonomous vehicles moving in a 3D space in the task of tracking a time-parametrized desired trajectory. For a purpose of an outer-loop (kinematic-level) control design one proposes to utilize the Vector Field Orientation (VFO) methodology which has been successfully applied and extensively tested so far in the area of wheeled mobile robots. Geometrical nature of the VFO approach leads to a non-oscillatory and fast-converging system response, and provides simple and intuitive tunning rules for a resultant controller. The inner loop (dynamic level) of a cascade is designed using a principle of Active Disturbance Rejection (ADR) which ensures robustness of the closed-loop system to modeling uncertainties of vehicle dynamics. Implementation of the proposed cascaded control law requires a feedback only from vehicle configuration variables (output-feedback). Performance of the proposed control system has been verified by simulations performed for the fully actuated as well as underactuated torpedo-like vehicles.