Travel Bike

The Travel Bike is a product configuration problem written in the COOM[X] language fragment. In addition to the City Bike, it contains numeric features and constraints involving arithmetics and aggregate functions.

fclingo

Problems involving large numeric ranges may time out when using the clingo encoding due to large groundings. Here, hybrid solver fclingo, which handles integers natively, can be used by specifying the --solver fclingo option.

Acknowledgements

The Travel Bike example has been provided by denkbares.

Usage

coomsuite solve examples/coom/travel-bike.coom --solver fclingo

COOM model

product {
    num .#/g    1-10000 totalWeight
    num .#/kg   0-10    maxWeight
    num .#/l    0-200   totalVolume
    num .#/l    0-200   requestedVolume
    Wheel               frontWheel
    Wheel               rearWheel
    Carrier             carrier
    Frame               frame
    Color               color
}

structure Carrier {
    0..3 Bag            bag
}

structure Frame {
    0..2 Bag            bag
}

structure Bag {
    Capacity            capacity
    Material            material
}

enumeration Capacity {
    attribute num/l volume
    attribute num/gr weight

    B10  = ( 10,  100)
    B20  = ( 20,  250)
    B50  = ( 50,  600)
    B100 = (100, 1200)
}

enumeration Material {
    Cotton
    Leather
    Polyester
}

enumeration Wheel {
    attribute   num/inch    size
    attribute   num/gr      weight

    W20 = (  20     650 )
    W22 = (  22     700 )
    W24 = (  24     800 )
    W26 = (  26     900 )
    W28 = (  28    1000 )
}

enumeration Color {
    Red
    Green
    Yellow
    Blue
}

behavior {
    explanation "The bike can have a maximum of 4 bags."
    require count(carrier.bag) + count(frame.bag) <= 4

    explanation "The total weight is equal to the weight of the front wheel plus the weight of the rear wheel plus the sum of the weights of all bags on the carrier and the frame."
    require totalWeight = frontWheel.weight + rearWheel.weight
                        + sum(carrier.bag.capacity.weight)
                        + sum(frame.bag.capacity.weight)

    explanation "The total weight must not exceed the maximum weight."
    require totalWeight <= maxWeight * 1000

    explanation "The total volume is equal to the sum of the volumes of all bags on the carrier and the frame."
    require totalVolume = sum(carrier.bag.capacity.volume) + sum(frame.bag.capacity.volume)

    explanation "The total volume must be greater than or equal to the requested volume."
    require totalVolume >= requestedVolume

    explanation "If the color is red, then the size of the front wheel must be 20."
    condition color = Red
    require frontWheel.size = 20
}

behavior Bag {
    explanation "If the material of the bag is leather, then the capacity must be B10."
    condition material = Leather
    require capacity = B10
}

Example solution

carrier[0]
carrier[0].bag[0]
carrier[0].bag[1]
carrier[0].bag[2]
frame[0]
frame[0].bag[0]
requestedVolume[0] = 200
totalVolume[0] = 200
totalWeight[0] = 3750
maxWeight[0] = 8
color[0] = "Red"
frontWheel[0] = "W20"
frontWheel[0].size[0] = 20
frontWheel[0].weight[0] = 650
rearWheel[0] = "W22"
rearWheel[0].size[0] = 22
rearWheel[0].weight[0] = 700
carrier[0].bag[0].capacity[0] = "B50"
carrier[0].bag[0].capacity[0].volume[0] = 50
carrier[0].bag[0].capacity[0].weight[0] = 600
carrier[0].bag[0].material[0] = "Polyester"
carrier[0].bag[1].capacity[0] = "B50"
carrier[0].bag[1].capacity[0].volume[0] = 50
carrier[0].bag[1].capacity[0].weight[0] = 600
carrier[0].bag[1].material[0] = "Polyester"
carrier[0].bag[2].capacity[0] = "B50"
carrier[0].bag[2].capacity[0].volume[0] = 50
carrier[0].bag[2].capacity[0].weight[0] = 600
carrier[0].bag[2].material[0] = "Cotton"
frame[0].bag[0].capacity[0] = "B50"
frame[0].bag[0].capacity[0].volume[0] = 50
frame[0].bag[0].capacity[0].weight[0] = 600
frame[0].bag[0].material[0] = "Polyester"