Spline Trajectory Verification And Execution - Newport XPS-Q8 Users Manual, Software Tools And Tutorial

XPS-Q8 Controller
XPSDocumentation V1.4.x (EDH0301En1060 — 10/17)
8.2.8

Spline Trajectory Verification and Execution

Here are four functions to verify or execute a spline trajectory:
• XYZSplineVerification(): Verifies a spline trajectory data file.
• XYZSplineVerificationResultGet(): Returns the last trajectory verification results,
actuator by actuator. This function works only after an XYZSplineVerification().
• XYZSplineExecution(): Executes a trajectory.
• XYZSplineParametersGet(): Returns the trajectory current execution parameters.
This function works only while executing of the trajectory.
The function XYZSplineVerification() can be executed at any moment and is
independent from the trajectory execution. This function performs the following:
• Checks the trajectory file for data and syntax coherence.
• Calculates the trajectory limits, which are the required travel per positioner, the
maximum possible trajectory velocity and the maximum possible trajectory
acceleration. This function defines the parameters for trajectory execution.
• If all is OK, it returns an "OK" (0). Otherwise, it returns a corresponding error.
The function XYZSplineVerificationResultGet() can be executed only after an
XYZSplineVerification() and returns the following:
• Travel requirement in the positive and negative directions for each positioner.
• The maximum possible trajectory velocity (speed) that is compatible with all
positioners' velocity parameters. It returns a value for the trajectory velocity, that
when applied, at least one of the positioners will reach its maximum allowed speed
at least once along the trajectory. So the returned value varies between
Min{Vmax_actuator} and
this value does not take into account that the positioners' acceleration can limit the
trajectory velocity. This is the case with splines that contain sharp curved segments.
• The maximum trajectory acceleration that is compatible with all positioner
parameters. At this trajectory acceleration, one of the positioners will reach its
maximum allowed acceleration during trajectory execution.
The function XYZSplineVerificationResultGet() returns the trajectory execution
limits that have previously been calculated by the XYZSplineVerification function.
Note on this function's response: Only the returned travel requirements are specific for
each positioner, the returned velocity/acceleration values are the same for all
positioners, because they represent the trajectory's velocity/acceleration.
To execute a spline trajectory, send the function XYZSplineExecution() with the
parameters for the trajectory velocity and the trajectory acceleration (the trajectory
acceleration that is used during the start and the end of the trajectory). The motion
profile for spline trajectories is trapezoidal. The function XYZSplineExecution() does
not verify the trajectory's coherence or geometric conditions (exceeding any
positioner's min. or max. travel, speed or acceleration) before execution, so users must
pay attention when executing a trajectory without verifying the trajectory the maximum
possible values. In case of an error during execution, because of bad data or because of
a following error (for example the trajectory acceleration or speed was set too high) the
motion group will make an emergency stop and will go to the disabled state. The
parameters for trajectory velocity and trajectory acceleration can also be set to zero. In
this case the controller uses executable default values which are the Min{All
V } for trajectory velocity and Min{All A
max_actuator
Finally, the function XYZSplineParametersGet() returns the trajectory execution
status with trajectory name, trajectory velocity, trajectory acceleration and current
executed trajectory element. This function returns an error if the trajectory is not
executing.
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Motion Tutorial
. However,
} for trajectory acceleration.
max_actuator