When you import Point-Cloud data, the chart shows the Point-Cloud data in (Cyan)and the Continuous Curve in(Pink).
In the chart below, the Continuous Curve does not follow the Point-Cloud data - this is intended and for illustration ONLY.
The two charts show as one chart after you successfully Fit the Continuous Curve to the Point-Cloud data.
Point-Cloud dialog > Fit Curve to Data tab
Original Data Accuracy
This is a judgment you must make. Start with 0.1, then reduce it to approximately 0.001 - but see below for more thoughts.
Auto-Fitcheck-box andFit Curve button
Usually, click the Auto-Fit button to make it active - see options
Increase the # Harmonics
Edit the # Harmonics
The Continuous-Curve becomes nearer to the Imported Data as you increase the # Harmonic.
Fit-Quality =0 >> 1
When Fit Quality Traffic Light becomes Green, ...
When the number in the Fit-Quality Number box is near to, or equal to, one(1), ...
... STOP - do not increase the number of Harmonics.
Click one of the four radio-buttons
○Points and Curve
The view of the Continuous-Curve and the Point-Cloud in the graphic-area match the P, V, or A button.
Steps to do:
A.Edit the # Harmonics
The Curve updates immediately each time you edit the# Harmonics
❑Auto-Fit check-box is clear.
The Curve only updates when you click Fit Curve
B.Do A again
Do until the Fit-Quality and the Traffic-Light becomes Green or Orange
Velocity and Acceleration Graphs and Filter Width
The default plot is for Position. If you want to look at the plot of the Point-Cloud as Velocity or Acceleration (), then click the V or theA icons.
If the plot of the Velocity or Acceleration data is noisy you can smooth the noise (remove the noise) with the Filter-Width. This may help you identify the original Motion-Law.
Original Data Accuracy
•Consider an Original Data Accuracy of 0.1, then reduce it to approximately 0.01.
•Do not enter a value that is more accurate than the original accuracy of the data. For example, if the data has 2 d.p. , then 0.05 OK, and 0.001 is not a sensible value. However, experiment, as you find that more accuracy gives you better results.
•Is the skill of the person that measured the Cam-Profile a factor?
•Is the cam clean? Is the cam worn? Is the cam damaged?
Machine Measurement Accuracy Approximations: per 100mm Diameter of Cam Diameter:
•Temperature-Controlled (18-22ºC) CMM approximately 0.2 - 5µm
•Non-temperature-controlled CMM approximately 2 - 10µm (~h4 for a 100mm shaft)
•Portable CMM approximately 5 - 20µm(~h5-h6 for a 100mm shaft)
•Test Rigs are variable, but you should aim for approximately 20 - 100µm (~h8-h9 for a 100mm shaft)