Fast trajectory tracking of wheeled mobile robots

To improve the limited response ability of wheeled mobile robots (WMRs) and ensure that WMRs track the given reference trajectories rapidly, this paper utilizes information preview (i.e. future reference information) to design a preview control strategy and driving voltage of wheeled mobile robot (WMR). First, a virtual controller was proposed for the kinematic model to ensure that the WMR tracks the given reference trajectory asymptotically. Then, a linear discrete-time state-space model of the proposed virtual controller was established, and the tracking problem was thus converted into a linear quadratic regulation problem for systems with given input on the basis of the dynamic model of the WMR and the linear model of the virtual controller. Finally, the feedback gain of the optimal preview control strategy was provided based on the solution of the Riccati equation. The proposed strategy for virtual controller modeling could be adopted for any discrete signal, which can facilitate signal processing and application. In addition, due to the utilization of the reference information in advance, the proposed strategy could realize rapid tracking with given trajectories. Simulations for sinusoid-type reference trajectories were carried out, and results show that the velocity and trajectory tracking errors of the WMR tended to zero rapidly, which verifies that the proposed preview control strategy is feasible. Copyright ©2020 Journal of Harbin Institute of Technology.All rights reserved.