Santa is determined to keep the temperature inside his Christmas Workshop perfectly stable. But every now and then, when someone opens the giant wooden workshop door, a cold North-Pole draft blows in and chills the room.
From previous experiments, the elves now know that:
- Every gust of cold air lowers the workshop temperature by exactly 2 °C.
- A small wind-chime sensor rings the moment the door begins to open, before the temperature actually starts falling.
- A precise wall-thermometer shows the current workshop temperature.
The elves propose a number of different control strategies:
Strategy 0 (Elf Chillbert): “I propose we do absolutely nothing. Temperature goes down, temperature goes up — that’s life in the North Pole! Why fight nature? Also, it’s cheaper.”
Strategy 1 (Elf Crystal): “I propose we listen to the wind chime.
Whenever the door opens, we measure how strong the draft is, calculate the expected cooling (since we know that ‘One unit of draft → 2 °C drop’). Thus, before the workshop cools, we turn up the heating by exactly the right amount! And no need to add corrections afterward; we rely entirely on this prediction”.
Strategy 2 (Elf Sagesip): “I propose we watch the wall-thermometer. If the workshop temperature falls below the target, we heat it. If it is too warm we cool. Let’s not guess things out — let’s react to what actually happens inside the workshop!”
Strategy 3 (Elf Snowbell): “I propose that we do what you two, Crystal and Sagesip, just proposed: we take action as soon as the chime rings and do what Sagesip does with the thermometer. I would indeed counteract the expected cooling immediately and correct any leftover error afterward.”
Strategy 4 (Elf Maxacta):“I propose a bold strategy: whenever the chime rings, we turn the heater to MAXIMUM, so to be safe AND be fast. And If it gets too warm… well… we’ll open a window!”
What would you do? Which elf do you think has the best idea for keeping the workshop temperature closest to Santa’s desired value?
a. 🧊😌🎄 Chillbert — I need to chill out, at least this December!
b. 🔔📏❄️ Crystal — I want to act early!
c. 🌡️👀🧤 Sagesip — I don’t like betting when I may get a cold. Let’s react to the actual temperature.
d. 🎶🛠️✨ Snowbell — I like combining ideas from different people.
e. 🔥⚡🪟 Maxacta — We may not just keep the workshop steady, we can do it fast!
f. 🌬️🚫🏠 None — With that draft, it’s impossible to keep the workshop steady!
g. ❄️💼💪 I only work in cold workshops. Disturbances improve productivity.
Related control topic: different control strategies