The output tracking control problem of nonholonomic chained form systems is studied in this paper and global<br>K-exponential output trackers are presented without persistent excitation or not-converging to zero on reference trajectories. First, a time-varying coordinate transformation is introduced to avoid manipulating exponentially converging signals. Then, with the help of theory of cascaded systems and linear perturbed systems, global K-exponential output trackers are successfully obtaine
