Generative Design in Civil Engineering Using Cellular Automata Rafal Kicinger June 16, 2006.

Generative Design in Civil Engineering Using Cellular Automata

Rafal KicingerJune 16, 2006

NKS 2006, June 16-18, 2006, Washington, DC 2

Outline

• Generative Design• Cellular Automata as Design

Generators– Steel Structures in Tall Buildings– Traffic Control Systems in Urban Areas

• Emergent Designer• Design Experiments• Experimental Results• Conclusions


Generative Design: Representation

• Design representations – One of the key aspects of any computational

design activity– Describe design’s form, its components, etc.– Incorporate domain-specific knowledge– Determine the space in which solutions are

sought

• Need to address important engineering objectives– Novelty– Optimization


Traditional Design Representations


Generative Design


Generative Design

• Cellular automata generating designs– Steel structural systems in tall buildings– Traffic control system in urban areas

• Evolutionary algorithms searching the spaces of generative representations (design embryos + design rules)


Cellular Automata as Design Generators

Steel Structural Systems in Tall Buildings



Traffic Control Systems in Urban Areas


Emergent Designer


Emergent DesignerSystem architecture


Design Experiments

Extensive Computational Experiments Conducted– Steel Structural Systems in Tall Buildings

• Exhaustive search of all elementary CAs started from arbitrary and randomly generated design embryos

• Generative representations based on 1D CAs evolved using evolutionary algorithms

– Traffic Control Systems in Urban Areas• Generative representations based on 2D CAs evolved

using evolutionary algorithms


Design Experiments• Steel structural

systems:– number of bays - 5– number of stories - 30– bay width - 20 feet– story height - 14 feet

• Arbitrary design embryos used:


Design Experiments

Traffic Control Systems– Number of network

nodes - 65– Number of network

links - 80– Number of traffic

signals - 25


Design Experiments• CA representation parameters:

– CA dimension: 1D and 2D– CA neighborhood radius: 1 and 2 – number of cell state values: 2 and 7– CA neighborhood shape (2D CAs): Moore– CA iteration steps (2D CAs): 14

• Evolutionary computation parameters:– evolutionary algorithm: ES– population sizes (parent, offspring): (1,5),

(5,25),(5,125)– mutation rate: 0.025, 0.05, 0.1, 0.3 – crossover (type, rate): uniform, 0.2– fitness: weight of the steel skeleton structure,

or the total vehicle time


Experimental Results• Exhaustive Search: Arbitrary Design Embryos

Best designs: Total weight:

Max. displacement:


Experimental Results

Distributions plotted with respect to two objectives:


Experimental ResultsExhaustive Search: Random Design Embryos

Simple X bracings K bracings


Experimental ResultsEvolutionary search of generative representations: steel structures


Experimental ResultsEvolutionary search of generative representations: traffic control systems


Conclusions

• Generative representations based on cellular automata proved to perform well for civil engineering problems where some regularity/patterns are expected, or desired

• They produced quantitatively better solutions (6-20% average performance improvement) than traditional design representations


Conclusions

• CA representations produced qualitatively different patterns than patterns obtained using traditional representations

• They can be efficiently optimized by evolutionary algorithms, particularly in the case of 1D CA representations


Credits

• The work on generative design of steel structural systems in tall buildings was conducted together with Drs. Tomasz Arciszewski and Kenneth De Jong

• The work on generative design of traffic control systems in urban areas was conducted with Dr. Michael Bronzini


Backup Slides• Evolutionary search of elementary

CAs: K bracings


Backup Slides• Evolutionary search of elementary

CAs: Simple X bracings

Generative Design in Civil Engineering Using Cellular Automata Rafal Kicinger June 16, 2006.

Documents

Transcript of Generative Design in Civil Engineering Using Cellular Automata Rafal Kicinger June 16, 2006.