A global continuous time-varying robust control law is proposed to stabilize the dynamic nonholonomic wheeled
mobile robot(WMR) with parameter uncertainty. The dynamic model of the WMR is transformed into an uncertain linear
subsystem and an uncertain nonlinear subsystem by a global invertible transformation. Then, the nonlinear subsystem is
transformed into a linear subsystem with disturbance by introducing an exponential decay term related to the initial state
values. Finally, a robust control law is designed to stabilize the whole system. Compared with the existed control laws, the
one proposed in this paper achieves continuity, asymptotic property and exponential rates at the same time, which is verified
by the simulation result.