Gregory Hornby

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To reduce the problem of premature convergence we define a new method for measuring an individual's age and propose the Age-Layered Population Structure (ALPS). This new measure of age measures how long the genetic material has been evolving in the population: offspring start with an age of 1 plus the age of their oldest parent instead of starting with an(More)
One of the main limitations of scalability in body-brain evolution systems is the representation chosen for encoding creatures. This paper defines a class of representations called generative representations, which are identified by their ability to reuse elements of the genotype in the translation to the phenotype. This paper presents an example of a(More)
One of the applications of evolutionary algorithms is the automatic creation of designs. For evolutionary techniques to scale to the complexities necessary for actual engineering problems, it has been argued that generative systems, where the genotype is an algorithm for constructing the final design, should be used as the encoding. We describe a system for(More)
A challenging task that must be accomplished for every legged robot is creating the walking and running behaviors needed for it to move. In this paper we describe our system for autonomously evolving dynamic gaits on two of Sony's quadruped robots. Our evolutionary algorithm runs on board the robot and uses the robot's sensors to compute the quality of a(More)
An evolutionary algorithm is used to evolve gaits with the Sony entertainment robot, AIBO. All processing is handled by the robot's on-board computer with individuals evaluated using the robot's hardware. By sculpt-ing the experimental environment, we increase robust-ness to diierent surface types and diierent AIBOs. Evolved gaits are faster than those(More)
∗Jason D. Lohn1, Derek S. Linden2, Gregory S. Hornby3, William F. Kraus3, Adán Rodŕıguez-Arroyo4, Stephen E. Seufert4 1NASA Ames Research Center, MS 269-1, Moffett Field, CA 94035 2Linden Innovation Research, PO Box 1601, Ashburn, VA, 20146 3QSS Group, Inc., Mail Stop 269-3, Moffett Field, CA 94035-1000 4NASA Goddard Space Flight Center, Greenbelt, MD 20771(More)
For computer-automated design systems to scale to complex designs they must be able to produce designs that exhibit the characteristics of modularity, regularity and hierarchy -- characteristics that are found both in man-made and natural designs. Here we claim that these characteristics are enabled by implementing the attributes of combination,(More)