Controller Overview

A P-type controller is implemented in src -> control -> controller.py based on the reference line width to output stage speed for achieving that line width. The configuration file containing process model parameters resides in config -> controller.yaml which has following structure:

# File -> controller.yaml

params:
    - gain: 201.22
    - bias: 22.705
    - C: 0.2
    - ref_line_width: 280

Controller Test

In order to test if the controller is working as expected, we can run tests -> controller -> controller_run.py file which takes reference line width as input parameter from controller.yaml config file to generate stage speed to achieve that line width.

python tests/controller/controller_run.py

For a given reference line widht of 280 microns, initial stage speed according to the controller is 0.44187 mm/s. After a new line is printed at this speed, we will estimate line width using a vision system and that will serve as input for next iteration. This process will go on till the controller converges (error is less than some delta).