Stefan, TVo, TJ, Danny

Before the break we created a guardian (TCS_RH_PWR.py) and adjusted the model that allowed the the user to choose between two states:

NOMINAL_RH_INPUT: allows the user to manually input ring heater power

FILTER_RH_INPUT: allows user to adjust the RH power using the inverse RH filter  (alog 44243) 

The guardian had a few flaws. In FILTER_RH_INPUT, it did not allow the user to input multiple RH settings until the prior ring heater change had reached its nominal value. The following controls diagrams show what these states used to do: 

Where iRH is the inverse RH filter, RH is our plant, and µ is the subtracted DC offset (prior RH setting before a power change was requested). x and x' represent the iRH filter input and output respectively and z and z' represent the plant input and output respectively. 

Stefan and I thought a bit about how we can make the ring heater control more robust. We wanted to create a design that allows the user to, in principle, make any number of changes within a given period of time and have the RH acquire the desired lens within a 2.5 to 3 hours from the last change as well as keep track of the history of the numerous requests . The following diagrams show the updated changes made to the h1tcscs model as well as the RH guardian to implement the aforementioned feature: 

Where iiRH is the inverse of the iRH filter. 

The most notable difference is in the addition of the iiRH filter and the connection of its output to the iRH input which allows us to keep track of how the plant is reacting to the changes made to the plant input minus the DC offset.  

A third state called "RESET" is also added to TCS_RH_PWR.py which allows the user to pause the RH value on its current value and clear the history of iRH as well as the iiRH filters.