MoveVelocitySCurve()

void MoveVelocitySCurve	(	double	velocity,
		double	accel,
		double	jerkPct )

Description:

MoveVelocitySCurve commands a constant velocity move (jog) with non-constant acceleration.

Parameters

velocity	Target velocity, UserUnits/second.
accel	Average acceleration, UserUnits/second/second. (peak up to 2× accel when jerkPercent = 100, see below)
jerkPct	Which defines the percentage of acceleration time which is smoothed, 0.0 to 100.0.

Note

In most cases, a servo motor has a feedback device mounted. Depending on feedback device resolution, one motor shaft rotation will produce fixed value of counts. Example: motor has a resolution of 8192 counts. This means if 8192 is entered as distance to move, motor will move single revolution. User can implement UserUnitsSet() to change to a different unit (ex: mm, inches, etc) from encoder counts.

Warning

Using a non-zero JerkPercent increases the maximum acceleration above the user-specified average. If your system can’t handle the higher peak, you risk overshoot or excessive load. The relation between average acceleration and maximum acceleration is:

\[ Maximum Acceleration \;=\; \frac{accel}{1 - \bigl(jerkPercent \times 0.005\bigr)} \]

• accel: the requested (average) acceleration value given in the MoveSCurve command.
• jerkPercent: the percent of time with non-zero jerk (0–100) given in the MoveSCurve command.
• Maximum Acceleration: the resulting peak commanded acceleration.

See the S-Curve Motion concept page for more information.

Note

Non-Blocking Execution Motion commands return instantly and do not pause code execution. Use MotionDoneWait() post-call to block execution until motion completes, or MotionDoneGet() to poll for completion.

Part of the Motion method group.

Sample Code:

axis->MoveVelocitySCurve(1000.0, 10000.0, 50.0);

RapidSetup:

Go to axis screen->Motion Profile box (left) to select type of motion
Go to axis screen->Motion Parameters box (right) to select values for motion

Motion Scope:

Velocity move (SCurve type) profile shown below:

See also

Velocity Motion,, MoveSCurve, MoveTrapezoidal, MovePT, MovePVT