S-curve and Trapezoidal Acceleration / Deceleration

S-curve

If the Jerk input of a motion function block is non-zero, S-curve acceleration / deceleration is used.

• The Acceleration input specifies the maximum acceleration / deceleration reached during changes in velocity.
  • The Jerk input specifies the constant rate of change of acceleration and deceleration used to cause a smooth transition to and from maximum acceleration / deceleration.
• The Deceleration input is unused.

Small Jerk Acceleration

The Figure: "Small Jerk Acceleration" is a velocity plot of the acceleration of a move when Jerk is a small value.

The smaller the Jerk value, the more gradual the rate of change of acceleration / deceleration when transitioning from one velocity to another.

Figure 1: Small Jerk Acceleration

Large Jerk Acceleration

This Figure: "Large Jerk Acceleration" is a velocity plot of the acceleration of a move when Jerk is a large value.

The larger the Jerk value, the more abrupt the rate of change of acceleration / deceleration when transitioning from one velocity to another.

Figure 2: Large Jerk Acceleration

Trapezoidal

If the Jerk input of a motion function block is zero, trapezoidal acceleration / deceleration is used.

• The Acceleration input specifies the linear acceleration rate.
• The Deceleration input specifies the linear deceleration rate.

This Figure: "Trapezoidal Acceleration" is a velocity plot of the acceleration of a move when trapezoidal acceleration is used (Jerk = 0 (zero)).

Figure 3: Trapezoidal Acceleration