The Annevolve project (open source project at
http://sourceforge.net/projects/annevolve) created a small piece of
software, EvSail 1.2, a virtual sailboat that moves under the
influence of virtual wind with controlling inputs of sail and keel
angle of attack. The Annevolve team created an ANN that can trim the
sails and adjust the rudder of a virtual sailboat. This allows the ANN
to sail around an island in near optimal time, the minimum possible
time. The trip around the island also includes a virtual boat to tack
upwind. This program is a mathematical model of sailboat physics
involving lift and drag of the keel and sails and vector resolution of
relative wind and water flows.
EvSail consists of the following principal components:
- Mathematical models of sailboat physics, involving lift & drag of
the keel & sails, and vector resolution of relative wind and water
flows. The virtual sailboat moves under the influence of wind with
controlling inputs of sail and keel angle of attack.
- An Artificial Neural Network (ANN) uses the relative wind hitting
the boat, the boat's speed through the water, and the relative
position of a target point as inputs. There are five input numbers.
The output of the ANN is the angle of attack of the keel and the angle
of attack of the sail.
-A fitness function that measures the degree of success of the ANN in
navigating the boat all the way around a circular island.
-A population of ANNs, each of which attempts to circumnavigate the
island. Each ANN is characterized by a set of several hundred weights.
The weights are in an array called a chromosome. Therefore the
population consists of an array of pointers to the chromosomes.
-Evolution software based on the Genetic Algorithm (GA) approach that
modifies the population of ANNs through many generations. This
approach seeks to increase the fitness values by replacing ANNs with
low fitness with offspring of ANNs with higher fitness
The Annevovle team is experimenting with the Evolution of Artificial
Neural Networks (ANNs). They are combining the two fields of
Evolutionary Computation and Artificial Neural Networks. Find out more
about EvSail and other ANN programs at the Annevolve project at: