Example 3: The tests of Example 2 are repeated, but now, the system is first accelerated to a constant speed 0.8ωnom in 0.2 s. Fig. 7 shows the reference tracking error during the acceleration, when using (26) and (32). It can be seen that, if the filter for step references (26) is used, a constant steady-state tracking error occurs. Better tracking capability is obtained when the feedforward filter is designed for trapezoidal references according to (32).