NCT04

A navigation system with anti-collision behavior for DD and car-like WMRs, that integrates redundant encoders data, inertial data, and absolute positioning data, is under development by the team of the project. Among other modules, a path-following controller, a vehicle's pose estimator, and an anti-collision system compose the navigation system. In this proposal the purpose is to further research on path-following control with the main goal of developing improved controllers with better performances when compared with the path-following controllers already developed using fuzzy-logic and input-output feedback linearization methods. Improvements are required in to ensure that the vehicle follows the predefined reference trajectory with high precision, for a large range of velocities, and in presence of uncertainties.The main issues to be investigated are the following: - Based on appropriate dynamic models formulations, experiments will be performed in order to identify and validate the parameters of WMRs prototypes; - The design of a velocity planner in order to achieve smooth vehicle acceleration and jerk minimization. Taking into account that certain polynomial splines minimize jerk, the core of the approach will be a variational principle that generates such splines; - In the design and implementation of the path-following controllers, intelligent control and model-based approaches, using nonlinear and adaptive control techniques, will be researched and applied. In particular, the nonlinear techniques include input-output feedback linearization and sliding mode. The robustness in WMR path-following control can be effectively accomplished by sliding mode control with on-line parameter identification, and, in the case of the input output feedback linearization controller, by an outer control loop based on Kalman-based active observer controller; - Further developments of our guidance system based on fusing redundant wheel encoders, inertial data, and positioning data provided by sensing natural and artificial landmarks.