Towards HB Agent Based Models?

Hello everyone!

I am currently thinking of Agent Based Models (ABM) for building assessment, specifically to understand how behavioural patterns affect building performance and vice versa.

The way I see it, and I could be wrong, to some extend these types of analyses are already included in E+ (and HB) in the sense that we can assign schedules of certain building components and systems (e.g. shading, windows aka n.v., thermostats, etc.) according to other independent variables (mainly outdoor temperature and irradiance) that we attribute to imaginary agents.

However, this mostly represents analyses using external (to the model itself) data, and not internally calculated outputs, which are essential for assessing occupant behaviour (e.g. open window when outdoor temperature is lower than..). Thankfully, HB already includes an array of advanced components able to calculate these parameters, especially comfort parameters and daylighting.

Does that mean that we could potentially use that information as input to agents that would populate the space of our model? I am thinking here in the same terms as a wind driven rain simulation workflow would work, where first a CFD study would analyse the wind velocity for every point of the mesh and the droplets would then be dropped in that mesh and their probabilities of their routes would be calculated. In the same way I would imagine we can calculate probabilities of occupant actions in 'points in time', where occupants would change their environments given the results of the simulation. This isn't really real-time but it is still a start and it is a quite good approximation of the nowadays-popular, low-control, mechanically ventilated buildings.

Now, I believe that I could model these type of agents, and their parameters, rules, probabilities, etc. If so, how interesting and especially how difficult would it be to create the component that would take the results of the simulation for a space as inputs for these agents?

I know the above is not totally clear but bare with me as this is shaped along your comments and ideas.

(an example for inspiration from 2011, agent based model architecture: https://vimeo.com/18967658)

Kind regards,

Theodore.

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Replies to This Discussion

Permalink Reply by Theodoros Galanos on January 3, 2016 at 7:47pm

Hi Chris and Mostapha,

First of all, happy new year! I wish you all a happy, healthy, and creative 2016.

Chirs, thank you once again for your informative answer.

I have been thinking a lot about this lately. I believe you are absolutely right to say that the type of behavior to be modelled will define if we actually need an ABM interface. If, as you say, the parameters modelled are temperature or radiation, then I imagine that a lot of studies can be done within E+, perhaps in the stepwise way you described earlier.

Additionally, and this is my main critic on ABM in general but I'll leave it for another discussion, the degree of freedom or interaction with the environment that an agent has dictates the possibilities for an ABM. In typical models this has to do with how you model innovation in agents, changes in their practices and norms (which generally isn't there in ABM models). In our case, it related to the type of environments our agents are situated in.

I can imagine two extreme cases of environments, with ofc a gradient of possible worlds between: the mechanically conditioned building and the naturally ventillated building.

In the first case, which btw is the one most encountered in my part of the world, the agents have minimal, to sometimes zero, control on their environment and no capabilities of adaptation and change. Imagine a typical building where the set points are set centrally, windows are not operable, and even the shading devices are sometimes out of their reach.

In this case, I can imagine ABM models helping only as a post processing tool. What that means is that we could potentially use them to analyze occupant behavior within this controlled environment. E+ would give us the hourly space performance and we would feed that to agents to see how they respond. Ofc, in terms of thermal comfort this is almost what your tools are doing. So, such an approach would have little value in an office building for example where people are assumed static but could be interesting in retail buildings where we could potentially model occupant movement according to building performance. The limits of this approach then is some sort of scenario testing of different settings and occupant (response) behavior to them. Here of course, you have a valid point of other building characteristics that should be modelled, apart from climate.

In the second case, that of an adaptive building, I believe ABM can be a tool that can be used in a co-simulation approach, as it has been used in the site Mostapha mentioned above. Again though, in ABM it is critical to not overdefine behavior but on the contrary to generate behavior from assigning simple rules to agents. This makes it difficult for me to find the limit of detail in the functions/statistics used to model occupant actions within the building (on windows, shading, thermostats, etc.).

Since ABM is better fitted to generate patterns that we encounter in the real world, I thought of developing a model that might do exactly that. It took me a while to think of a pattern that would be interesting, but I think I finally have it. It is a bit of a grand gesture of course, but should be worth it.

As you know better than me from your research, the adaptive comfort studies found a quite peculiar fact about the tropics. The sentence went something like this (I'm botching it probably), "people in the tropics tend to prefer environments that are below the limits of their neutral comfort". Or simpler, people just want to the space to be colder than what one calls neutral.

My simple minded explanation, after leaving in the region, is that the explanation for this is to be found in the interface between outside and inside. The temperature gradient in that interface is what makes people feel more comfortable in uncomfortable (i.e. colder) conditions.

So what if we would introduce a shaded, open, naturally ventilated space prior to a MV building's entrance and then increase your indoor temperatures in the building? Or what if we introduced a temperature gradient in the different spaces a visitor/occupant passes through as he enters the building. I feel that energy modelling cannot really understand the impact of these interventions on occupants, at least in its basic form. I think this is where ABM could be useful. Building a model that can generate the above mentioned pattern and then using it to analyze different types of strategies to occupant behavior.

I wanted to write the things above in a more structured way but I forgot my cheat-sheet at home :) I hope I made some sense.

I will try and be patient and follow the route you suggest however, understanding the E+ resources first and then moving to connecting it to ABM.

I just thought I'd describe the sort of research questions I have in mind for this, hoping someone finds it interesting as well!

Kind regards,

Theodore.

P.S.: I have left out other areas that would be suitable for ABM modeling within buildings. For example the area of health and safety. ABM is an amazing tool to model occupant behavior in extreme events, e.g. fire in a building or toxic smoke, etc. in order to analyze evacuation patterns and optimize building design. Even though this is something I am also interested, I intentionally did not go into it since we are mostly dealing with environmental design here.

Permalink Reply by Theodoros Galanos on January 6, 2016 at 8:04pm

Hi Chris,

It would be very helpful if you could get me in touch with your colleague. Any information on how to navigate this new rabbit hole would be invaluable.

Kind regards,

Theodore.

Permalink Reply by Theodoros Galanos on January 4, 2016 at 11:46pm

Hello again!

Following Chris's advice I skimmed through the E+ reference guide. Took a lot of notes and learned a lot of interesting things I did not know. Unfortunately, the most difficult parts of the guide for me were exactly the two group of objects that are most interesting for this: EMS and ExternalInterface.

I will keep reading and testing, currently also downloading BCVTB at work. I am also currently contacting two former colleagues one with a very strong background in ABM and coding and the other researching on building energy simulation. Will probe to see if this is interesting to them and will let you know.

Maybe we can coordinate something in the immediate future.

Have a nice day.

Theodore.

Permalink Reply by Theodoros Galanos on January 5, 2016 at 2:31am

This looks very promising as well. It is a new effort but it seems to be a very good start on an ABM framework for GH.

http://www.grasshopper3d.com/group/quelea-agent-based-design-for-gr...

https://www.youtube.com/watch?v=zQ4m5KdYyBs