![](bg8.png)
amplitude natural frequency resonance, so the robot
arm doesn’t resonate with actuation system. Also,
considering the displacement (marked with blue in
the figure), it can be observed that the position error
is zero. The overall behavior of the structure is a
very good one.
For the medium speed moves, the stepper motors
may lose steps, but this phenomenon occurs
occasionally and can be considered insignificant if is
evaluated as a ratio lost steps / total number of steps,
meaning that an open loop control can still be
successfully applied to the system. There is a low
amplitude oscillation of the robot’s arm, mainly at
24.6 Hz, induced by the actuation system, but it
induces only a small amplitude natural frequency
resonance, so the robot arm doesn’t resonate with
actuation system. The displacement record reveals a
transient evolution around the final position,
introducing a transient position error, having 2 mm
maximum amplitude and with a short duration, 0.2
seconds. At the end of the transient evolution, the
robot stops on the desired position and the position
error is zero. The overall behavior of the structure is
a good one.
ACKNOWLEDGEMENTS
The research presented in this paper was supported
by the Romanian National University Research
Council CNCSIS through the IDEI Research Grant
ID93 and by FP6 MARTN through FREESUBNET
Project no. 36186.
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