Use a Point Cloud to:
Import-data as a text-file.
Typically, the data is for a cam-profile, which is measured with a Coordinate Measurement Machine (CMM). The measurement data is taken 'as is'. Numerical techniques approximate the motion-derivatives, which are usually noisy.
Fit-a-Curve to the imported-data.
The curve is a continuous-function that is a good-fit to the imported-data. We use the function to evaluate the motion-derivatives, which are usually smooth.
To open the Point-Cloud dialog-box:
Import a data-file [text file] you want to use as the Point-Cloud.
Do these steps:
Click the Browse... button to select data-file you want to import.
The file-name will show in the File-name to Import [Read-Only] box
B. Edit File-Format
Each data-point in the data-file must include:
Each data-point must be on a new line, and ideally as two columns of data.
However, not all data-files have only two columns of data.
Use the Edit File-Format box to filter extra columns of data from the data-file
See Data-File Formats below.
c. Import button
Click the Import button to import the Point-Cloud data file.
The Point-Cloud will show as a continuous line in the graphic-area immediately.
x , y
When you add a Point-Cloud FB, you select a Part. The Part has an Origin where its coordinates are X=0 and Y=0.
If the Point-Cloud data has an offset to it, then remove the offset with the X and Y data boxes.
File Rotary Units ; File Linear Units
Select the units that matches the units of the original Point-Cloud data-file
Pre-Select a File Format
To help you with the formatting, you can use the Pre-Select a File Format drop-down list-box.
When any of these formats do not represent the format of the data in your data-file, then edit the format in the Edit File Format box directly.
When you successfully import a Point-Cloud, the chart shows the Point-Cloud in [Dark Blue] and the Continuous Curve in [Light-Blue].
Do these steps:
Fit a Continuous Curve to the Point-Cloud Data
This is a judgement you must make. I enter 0.1, then reduce it to approximately 0.01 - see below for more thoughts.
Usually, you can click the Auto-Fit... check-box to put a tick in the check-box - see options
Edit the # Harmonics
The Continuous-Curve improves each time you edit the # Harmonic.
When Fit Quality Traffic Light becomes Green, STOP, or
When the number in the Fit-Quality Number box is near to, or equal to, one , STOP
If you add more harmonics, the fitted-curve may oscillate with an amplitude equal to the Original Data Accuracy.
Click one of the four radio buttons:
Clear the Auto-Fit check-box if the Point-Cloud has many points. E.g. > 10000 points / lines.
You must click use the Fit Curve button to update the Fitted-Curve,
Repeat until the Fit-Quality and the Traffic-Light becomes Green or Orange
Velocity and Acceleration Filter Width
The default plot is for Position. I do not use the V or the A buttons as I cannot find a good use to do so.