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Optmodel for Optimization of Aircraft loading

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New Contributor
Posts: 2

Optmodel for Optimization of Aircraft loading

Hello,

 

 I could use any help in building an Optmodel for cargo loading optimization on C-5 and C-17 aircraft. The following are constraints; the aircraft has longitidunial center of balance limits, axel weight limits for vehicles, overweight cargo in zones limits and pallets either too tall or to heavy in zones. If the aircraft's cargo is not within the limits than it is penalized with costs. I am trying to build the optmodel that calculates these for a set of shipping data onto multiple aircrafts and also is able to sort the shipment so that less penalties occur. Does anyone have experience building linear optimization models with binary variables?

 

Thank you,

Jacob

Super User
Posts: 11,134

Re: Optmodel for Optimization of Aircraft loading

Since you say C5 and C17 and those are military aircraft I have what may sound like an odd question. Is any of this load-out related to a tactical mission?

 

I ask because many years ago as an additional duty I was an Army unit movement officer and went through a short (week long) course on air load planning. One of the considerations was sometimes "what do you need first" when you get to the location as that affected order.

 

For instance if I have to load vehicles without cargo due to size/shape of the cargo, I might want the vehicle closer to the load ramp as a time sensitive bit would likely make it easier to move the cargo directly onto the waiting vehicle instead of move the cargo, then the truck then load on truck which could be the result of a pure optimal load weight/cube distribution optimization.

New Contributor
Posts: 2

Re: Optmodel for Optimization of Aircraft loading

Hello,

Thank you for your service.This is not for a tactical mission nor is the
model a time series or incorporates sensitivity to time. This model is for
peacetime planning of cargo though, I could look at wartime planning if I
still have time. I need to develop a functional SAS model in three days.
The C-5 has a maximum allowable cabin load of 150,000lbs during peacetime
and the C-17 has 90,000lbs during peacetime. There are 5 penalty fees that
I am calculating for data sets of cargo that will be loaded onto multiple
C-5s and C-7s.

The penalty fees are as follows:

Longitudinal Center of Balance (CB) fee: The Center of Balance of an
aircraft is where the center of weight distribution is on the aircraft.
There are optimal CBs for different amounts of total weights onto the C-5
and C-17. It is penalized with by a specific formula for how far the
calculated CB is from the optimal CB range for different total weights of
allowable cargo loads. This prevents the plane from being to nose or tail
heavy. I can explain this further if you are interested.

Axel weights too heavy on vehicle loaded in a zone penalty fee

Total cargo weight in a zone too heavy penalty fee

Pallet too heavy or to tall penalty fee


Ramp fee
If the cargo is too close to the ramp and even touches the ramps on the
plane usually happens if cargo is not stored correctly with enough space in
between.

I am trying to calculate these penalty fees in SAS with sample cargo data.
I would like to optimize the model with proc optmodel so that planning the
storage of cargo in these planes yields the lowest amount of penalties and
saves the most money.

If you have experience in building these models and are interested in
helping I may provide you more information and also give compensation and
contribution for your help.

Thank you







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Super User
Posts: 11,134

Re: Optmodel for Optimization of Aircraft loading

I mainly asked the question because others that do optimization might not realize that load time sometimes figures into these.

 

Do you have a good CB calculator of the individual vehicles? That was our biggest headache but the actual plane load plane was actually more of a paper and pencil exercise once we had vehicle loads as we would not be doing any palletized.

Though I do remember so of the solutions actually involved smaller vehicles or trailers actually the load ramps.

New Contributor
Posts: 3

Re: Optmodel for Optimization of Aircraft loading

I am using SAS to calculate the CB. All I need are vehicle axle weights. The CB is going to be calculated for the whole aircraft with cargo on it. Do you know anyone who has experience with PROC OPTMODEL? There is a way to build constraints (the fees I described) so that SAS makes an optimal plan for loading the cargo.

SAS Super FREQ
Posts: 8,820

Re: Optmodel for Optimization of Aircraft loading

HI, I am not sure the the Enterprise Guide forum is the correct forum for PROC OPTMODEL questions. All the other questions about PROC OPTMODEL are posted in the Mathematical Optimization, Discrete-Event Simulation, and OR forum:
https://communities.sas.com/t5/Mathematical-Optimization/bd-p/operations_research

So that might be a better place to post your question. Typically, it helps if you can post some sample data along with your question and an example of the code you've tried.

cynthia
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