Two Velocity S-Curve

In the Two-Velocity S-Curve profile, the acceleration curve of the profile is divided into two equal parts. In the first half, the acceleration increases at a constant rate. In the second half, the acceleration decreases at a constant rate. This generates a smooth “S” shaped acceleration curve. After the axis accelerates to the profile velocity, the axis accelerates at a constant intermediate acceleration rate until it reaches the second velocity. After reaching the second velocity, the axis decelerates with a “S” shaped deceleration curve generated similarly as the acceleration curve.

The intermediate acceleration used to accelerate from the first velocity to the second velocity is calculated automatically. The intermediate acceleration can never exceed the specified profile acceleration. If the target position is too close to reach the second velocity with the given acceleration and deceleration, the axis will start decelerating before reaching the second velocity.

The first velocity must be smaller than the second velocity. If the first velocity is greater than the second velocity, it will be set equal to the second velocity.

Two-velocity profiles are incompatible with jog or velocity commands.

This profile uses the following profile parameters:

Parameter	Description
Velocity	First target velocity
Acc	Average acceleration
Dec	Average deceleration
Starting Velocity	Initial velocity
End Velocity	Final velocity
Second Velocity	Second target velocity

The following plots show the position, velocity, acceleration, and jerk of a two-velocity S-curve profile.