Why use a Polynomial-Fit FB?

It is often the case that your 'motion-design' is given to a 'Tool-Part'. Then, you add more Parts and join other Parts to the Tool-Part to create a more complex kinematic-chain.

A different Part, with a different motion to the Tool-Part, is driven. This is normal inverse-kinematics.

If you want to drive the Part with a servo-motor, you can use a Measurement FB and a Graph FB, and can give a servo-controller the required motion of a servo-motor as a series of data-points.

While this is often satisfactory, it is often preferable to give the servo-controller a series of polynomials rather than a series of a data-points.

The output from the Poly-Fit FB is the 'best-fit' motion of the input, but defined as a series of one or more 5th order Polynomials. You can save the output of the 'best-fit':

as 'motion-values' at its output-connector
to a CSV file,
in the format required for a Schneider Electric [Elau] servo-controller.

Note: The Poly-Fit FB uses all three data-channels to find the 'Best-Fit' to the data at its input-connector.


See also: Polynomial Fit dialog-box


Add Polynomial FB

Add Polynomial-Fit FB

Modelling FB toolbar > Polynomial-Fit FB [Above Graphic-Area]

Menu :

Add menu > Add Polynomial-Fit  FB

Dialog-Box :

Polynomial Fit dialog-box

Add :

 

 

 

STEP 1.Add the Polynomial-Fit FB to the graphic-area
1.Click Modelling FB Toolbar > Add Polynomial Fit FB
2.Click again in the graphic-area to 'place' the Polynomial-Fit FB.

The Polynomial Fit FB is now in the graphic-area.

STEP 2.Connect a wire to its input-connector

Each wire you connect to the Polynomial-Fit FB usually has three data-channels. See Data-Channels.

1.Add a Measurement FB to measure the linear or angular dimension you want to control with a Servo-motor
2.Connect a wire from the Measurement FB to the Polynomial Fit FB
STEP 3.Open the Polynomial-Fit FB dialog-box:
1.Double-click a Polynomial-Fit FB in the graphic-area

or


 

Tutorial and Reference Help Files for MechDesigner and MotionDesigner 13.2 + © Machine, Mechanism, Motion and Cam Design Software by PSMotion Ltd