I believe you are looking for the distinction between closed loop and open loop controllers. IIUC this theorem only applies to open loop controllers. OP’s flowchart does not contain a feedback loop. For comparison, Richard Kennaway’s flowchart has a feedback loop between Z and R.
An example of an open loop controller is a dishwasher or laundry machine.
All animals are examples of closed loop controllers.
I consider “open loop control” almost a contradiction in terms. I mean, I don’t have anything to quarrel with in the Wikipedia article, but it’s not an effective way to actually control anything, unless there’s a closed-loop controller wrapped around it. (Often this takes the form of a human being inspecting and adjusting the equipment.) One might as well call the screws holding a piece of furniture together an open-loop controller.
Perhaps I’m off on this but wanted to just ask. How much of that term being a contradiction is driven by the lack of a good underlying model of something. I’ll use the house temperature example here.
We have a very good model (by assumption here) of energy transmission from the exterior to the interior. We have a controller (thermostat) that only measures external features, say outside temp and maybe light and a time duration for when and how long to run either the air conditioner or heating. With a good model (and probably a good initialization at installation) that regulator seems like it would do a good job of hitting the defined internal temp target without needing to monitor the internal temp.
That certainly fails the GRT on the grounds it’s a lot more complicated than it needs to be as measuring the internal temp and then activating the AC or heating is pretty simple and straightforward. But having a good model seems to fit well with the Shannon entropy aspects—the model itself tells us what is needed about the internal temp so monitoring/sampling that variable is not necessary.
Is the complicated regulation no an open loop control case? Or is it still something of a contradiction in terms in your view?
There’s the rub. Your model will have to not only know the external temperature, but also the conductivity of the walls, the power delivered or extracted by the heat/cold source, the people or pet animals in the room and how much heat they are generating, the temperature in the adjoining rooms, and all the other factors affecting the temperature that the designer may not have thought of.
All to avoid the cost of a thermometer which you’ll need anyway to calibrate the model. This is Heath Robinson, not practical engineering.
I believe you are looking for the distinction between closed loop and open loop controllers. IIUC this theorem only applies to open loop controllers. OP’s flowchart does not contain a feedback loop. For comparison, Richard Kennaway’s flowchart has a feedback loop between Z and R.
An example of an open loop controller is a dishwasher or laundry machine.
All animals are examples of closed loop controllers.
I consider “open loop control” almost a contradiction in terms. I mean, I don’t have anything to quarrel with in the Wikipedia article, but it’s not an effective way to actually control anything, unless there’s a closed-loop controller wrapped around it. (Often this takes the form of a human being inspecting and adjusting the equipment.) One might as well call the screws holding a piece of furniture together an open-loop controller.
Perhaps I’m off on this but wanted to just ask. How much of that term being a contradiction is driven by the lack of a good underlying model of something. I’ll use the house temperature example here.
We have a very good model (by assumption here) of energy transmission from the exterior to the interior. We have a controller (thermostat) that only measures external features, say outside temp and maybe light and a time duration for when and how long to run either the air conditioner or heating. With a good model (and probably a good initialization at installation) that regulator seems like it would do a good job of hitting the defined internal temp target without needing to monitor the internal temp.
That certainly fails the GRT on the grounds it’s a lot more complicated than it needs to be as measuring the internal temp and then activating the AC or heating is pretty simple and straightforward. But having a good model seems to fit well with the Shannon entropy aspects—the model itself tells us what is needed about the internal temp so monitoring/sampling that variable is not necessary.
Is the complicated regulation no an open loop control case? Or is it still something of a contradiction in terms in your view?
There’s the rub. Your model will have to not only know the external temperature, but also the conductivity of the walls, the power delivered or extracted by the heat/cold source, the people or pet animals in the room and how much heat they are generating, the temperature in the adjoining rooms, and all the other factors affecting the temperature that the designer may not have thought of.
All to avoid the cost of a thermometer which you’ll need anyway to calibrate the model. This is Heath Robinson, not practical engineering.