- #1
JayD
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S-Curve Equations??
Hi All,
Am new to this but here goes.
I am trying to model a 7 segement S-Curve Motion Profile (see http://en.wikipedia.org/wiki/File:Third-order_motion_profile.svg" ) with VBA. I am wanting to use a linear encoder value to determine the switching points between the segments.
I am using the following equations:
A = A + J * t
V = V + (A * t) + (0.5 * J * t ^ 2)
X = X + (V * t) + ((A / 2) * (t ^ 2)) + ((J / 6) * (t ^ 3))
x = displacement
v = velocity
a = acceleration
j = jerk
t = time interval
I am struggling with the final change over from segment 6 to 7 (constant negative acc to non constant negative acceleration) as I want to use distance to Target (X_Target - X) as a trigger.
The constraints I have are:
The variables are:
Hope this makes sense.
Any suggestions/help would be appreciated.
Cheers
JD
Hi All,
Am new to this but here goes.
I am trying to model a 7 segement S-Curve Motion Profile (see http://en.wikipedia.org/wiki/File:Third-order_motion_profile.svg" ) with VBA. I am wanting to use a linear encoder value to determine the switching points between the segments.
I am using the following equations:
A = A + J * t
V = V + (A * t) + (0.5 * J * t ^ 2)
X = X + (V * t) + ((A / 2) * (t ^ 2)) + ((J / 6) * (t ^ 3))
x = displacement
v = velocity
a = acceleration
j = jerk
t = time interval
I am struggling with the final change over from segment 6 to 7 (constant negative acc to non constant negative acceleration) as I want to use distance to Target (X_Target - X) as a trigger.
The constraints I have are:
- current velocity (V)
- final velocity (V_f =0)
- current acceleration (A)
- final acceleration (A_f =0)
- current displacement (X)
- final displacement (X_f =X_Target)
The variables are:
- Time (t)
- Jerk (J)
Hope this makes sense.
Any suggestions/help would be appreciated.
Cheers
JD
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