Reflexxes Motion Libraries  Manual and Documentation (Type II, Version 1.2.6)
About the Flag RMLFlags::PHASE_SYNCHRONIZATION_IF_POSSIBLE

Time-synchronized trajectories can be generated from any arbitrary state of motion, but to generate phase-synchronized trajectories, certain conditions have to be fulfilled. The flag RMLFlags::PHASE_SYNCHRONIZATION_IF_POSSIBLE allows user to always generate phase-synchronized trajectories if possible. In order to demonstrate the behavior difference between the flags

the following diagram shows the path and trajectories of two different motions. The left one was generated using the flag RMLFlags::ONLY_TIME_SYNCHRONIZATION, and the right one using the flag RMLFlags::PHASE_SYNCHRONIZATION_IF_POSSIBLE. In both cases the desired target state of motion ${\bf M}_0^{\,trgt}\,=\,\left(\vec{P}_{0}^{trgt},\,\vec{V}_{0}^{trgt},\,\vec{0}\right)$ is reached after 3074 milliseconds for the first time. Because the trajectory started from an arbitrary initial state of motion ${\bf M}_0 $, only time- but no phase-synchronization is possible. Also in both cases, the flag RMLPositionFlags::RECOMPUTE_TRAJECTORY is used, such that after reaching ${\bf M}_0^{\,trgt} $ at $t\,=\,3075\,ms$, ${\bf M}_{3075}^{\,trgt}\,=\,{\bf M}_0^{\,trgt}$ is the new desired target state of motion. In this case, however, a phase-synchronized trajectory can be generated, because all input vectors are collinear now. This can be seen in the right diagram. The left diagram shows the corresponding time-synchronized trajectory.

In the two top diagrams, one can clearly recognize that the second part of the phase-synchronized trajectory is a straight-line motion instead of an eight-shaped path in the case of time-synchronization.



BehaviorAfterFinalStateIsReachedValues.png


PhaseSynchronizationIfPossible.png



The position diagram ( $ \vec{P}_i(t)\ =\ \left(\,\!_1p_i(t),\,_2p_i(t)\right) $) also contains the positional extreme values depicted in darker colors (cf. RMLFlags::EnableTheCalculationOfTheExtremumMotionStates).

This example was generated using the same example as on page Behavior after the Final State of Motion is Reached. Further information about the different synchronization behaviors can be found on page Synchronization Behavior.



Note:
The examples above have been generated with the Type IV Reflexxes Motion Library, which takes into account the values of


User documentation of the Reflexxes Motion Libraries by Reflexxes GmbH (Company Information, Impressum). This document was generated with Doxygen on Mon Jul 7 2014 13:21:09. Copyright 2010–2014.