Hierarchical fuzzy control for autonomous navigation of wheeled robots
- « Previous Article
- Table of contents
- Next Article »
The autonomous navigation wheeled robots (WR) requires integrated kinematic and dynamic control to perform trajectory tracking, path following and stabilisation. Considering a WR is a nonholonomic dynamic system with intrinsic nonlinearity, unmodelled disturbance and unstructured unmodelled dynamics, fuzzy logic system based control is appropriate and practical. However, the multivariable control structure of the WR results in the curse of dimensionality of the fuzzy design and prevents a domain expert from building the linguistic rules for autonomous navigation. Hierarchical fuzzy design decomposes the controller into three low-dimensionality fuzzy systems: fuzzy steering, fuzzy linear velocity control and fuzzy angular velocity control, so that manual construction of each rule base becomes feasible and easy. The proposed design enables a WR to perform position control in trajectory tracking and velocity profile tracking in continuous drive. The coupling effect between linear and angular motion dynamics is considered in the fuzzy steering by building appropriate linguistic rules. To facilitate the autonomous navigation design and verification, a prototype and the model of a kind of WR have been developed, and equipped with the hierarchical fuzzy control system. The simulation and experimental results are shown and compared.