how to setup the right equation for this optimization problem?

Hey guys,

I try to run an optimatiation algorthm for a facade system.

the attached image shows a section of the shape I try to optimize. The edge of the glas (green) connected to my sunshading panel (Black) can move in diffent positions under a given range.

My aim is to minimize the w/m2 of direct sun irradiation on the analysing surface (red) but maximize the m2 of transparent glas at the same time. It doesnt matter which software (Diva, Ladybug, etc.) I use. my question goes more in the direction how to setup the equation I need to find my fitness value for galapagos.

If I just want to minimize the sun irradiation, of course my facade system just "shuts down" and close as much as possible to hide the floor against the sun rays. So my glas m2 goes to almost 0.

I try to find the best equilibium between both parameters. Perfect would be to setup an equation were I can adjust the weighting of the fitness criteria. 80/20 or 50/50 ....

and I do not know how to setuo an equation which deals with both units....the w/m2 for the floor and the m2 for the glas...

Has someone any experience in that and could help me?

thanks....Horst

Replies to This Discussion

Permalink Reply by Nitë on April 17, 2015 at 11:02am

Hi Horst,

I am struggling with a similar problem trying to optimize WWR for multiple objectives using Octopus.Have you soled this problem?if so can you give me some hints?

Thanks,

Permalink Reply by Damon on April 17, 2015 at 12:34pm

I've never done this before, but reading your post is interesting. Here's my thought, for what it is worth:

- First, find the best solution for the irradiation, minimum W/m2, minimum glass m2.

- Second, find the worst solution for the irradiation, maximum W/m2, maximum glass m2.

These two extremes are easy and will not require an iterative script, just measurements in the two extreme configurations.

- Finally, you'll have your fitness criteria for galapagos. If going for 80/20, that would be 0.8*Glass_max / 0.2*Sun_min, or whatever other ratio you want.

Caveat, I have no idea if this is actually an optimized solution, but it's an idea to test.

Permalink Reply by Nitë on April 17, 2015 at 1:03pm

Hi Damon,

Thanks for the prompt reply.I feel like ive been talking to myself in this page the past few days.I must admit im a beginner and there are not much tutorials online for simulation based optimization.

I chose to use Octopus because of multiple objectives.(location, orientation, daylight factor, annual heating use, annual heating use.).I use Ladybug and Honeybee for the daylight environmental and energy analysis.

I am not quite sure how to connect the genomes to the geometry that is supposed to move-the window.

Check this video> it should look something like this: https://www.youtube.com/watch?v=6ssgXi9hSn0

Many thanks for the input, I will try it right away.I have some more questions:

1. First, find the best solution for the irradiation, minimum W/m2, minimum glass m2.

- should I put them in a gene pool or sliders?or a process that would give feedback from the simulations?

2.- Second, find the worst solution for the irradiation, maximum W/m2, maximum glass m2.

This could be the other genome?

Finally, you'll have your fitness criteria for galapagos. If going for 80/20, that would be 0.8*Glass_max / 0.2*Sun_min, or whatever other ratio you want.

Should I put these fitness values in numbers, or at the solver window(minimize or maximaze), I know that Galapagos supports objective only.

I have attached the images to see what I have started and another example for daylighting and shape(just for the structure of the study, I also cant figure out how she connected the dots, thats for the second part of my study, after I determine wich WWR is the fittest for few locations, to optimize the shape of the facade.)But I am not quite sure If the proces should be at the same time, both shape and WWR.

thanks again...

Best,

Nita