4 ms·

In the case of a thermostat you could define a goal temperature for a given time range (e.g. 18C during the day, 10C at night) and then your loss is, say, the s

In the case of a thermostat you could define a goal temperature for a given time range (e.g. 18C during the day, 10C at night) and then your loss is, say, the squared difference from goal and current temperature. But I agree that in many cases it is difficult to define a goal.

taeric 7y ago
My point was supposed to be that your goal will vary across time. Week of vacation at home? Probably optimizing for comfort. Standard work week where you aren't home all day? Cost will be big. Of course, getting costs in there could be a little tricky. Not impossible, just likely a ton of heuristics. And there is some level of stress where maintaining a temp might be cheaper than quickly getting to it, depending on how far you will vary based on being off. Which is just a long way to say it is easier to keep the house warm on warm days. :) If you drive a lot, this would be akin to trying to find the optimum spot to hold the gas pedal. Sounds like something you could look for, but odds are high that it has to vary based on circumstances. So, in the end, we aren't looking for a static parameter, but a system of dynamic parameters to keep in tune.
- noelwelsh 7y ago
  The usual way a thermostat works is the user specifies goal temperatures in time ranges and the thermostat tries to achieve them. E.g. our thermostat allows, IIRC, 4 different segments per day so we have morning (warmish), daytime (minimal heating), evening (warmish), night (minimal). The optimization problem them becomes one of achieving these goals. To account for the dynamics / circumstances you can augment the input the thermostat receives from just the current temperature to also include information about the rate of change of temperature (velocity and acceleration). This is the idea behind PID controllers and it allows things like easing off the heating if the house is warming quickly so the thermostat doesn't overshoot the goal.

taeric 7y ago

My point was supposed to be that your goal will vary across time. Week of vacation at home? Probably optimizing for comfort. Standard work week where you aren't home all day? Cost will be big. Of course, getting costs in there could be a little tricky. Not impossible, just likely a ton of heuristics. And there is some level of stress where maintaining a temp might be cheaper than quickly getting to it, depending on how far you will vary based on being off. Which is just a long way to say it is easier to keep the house warm on warm days. :) If you drive a lot, this would be akin to trying to find the optimum spot to hold the gas pedal. Sounds like something you could look for, but odds are high that it has to vary based on circumstances. So, in the end, we aren't looking for a static parameter, but a system of dynamic parameters to keep in tune.

noelwelsh 7y ago
The usual way a thermostat works is the user specifies goal temperatures in time ranges and the thermostat tries to achieve them. E.g. our thermostat allows, IIRC, 4 different segments per day so we have morning (warmish), daytime (minimal heating), evening (warmish), night (minimal). The optimization problem them becomes one of achieving these goals. To account for the dynamics / circumstances you can augment the input the thermostat receives from just the current temperature to also include information about the rate of change of temperature (velocity and acceleration). This is the idea behind PID controllers and it allows things like easing off the heating if the house is warming quickly so the thermostat doesn't overshoot the goal.