Chapter 6 Flashcards
Adaptation
Evolutionary robotics
Generating adaptive robots that evolve through a process analogous to natural evolution
Genotypes
The encoding of the characteristics of the robots
Phenotypes
The characteristics of the robots
Fitness
The evaluation of the performance of the robots with a scalar value
Offspring
Robotic copies of the best parent genotypes
Variations
Differences of genotypes introduced through mutation or other genetic operators
Fitness Function
The function that rates the ability of a robot
Developmental process
The rules that determine the relationship between the genotype and phenotype
Genetic algorithm
Operates on genotypes constituted by vectors of binary values , selects the reproducing genotypes stochastically with a probability proportional to their relative fitness, and generates variations through recombination and mutations.
Recombination
Divides the genotype of two reproducing individuals in two or three parts and by pasting some of the parts copied from the first genotype with complimentary parts copied from the second genotype
Evolutionary Strategies
Operates on genotypes formed by vectors of real numbers and generates variations by perturbing all real numbers with small randomly generated values
Modern evolutionary strategies
An extended version of evolutionary strategies that combine the matrix of random variations and the fitness received by offspring to estimate either the correlation among variations leading to high fitness or the gradient of the expected fitness.
OpenAI-ES algorithm
A natural evolutionary strategy that estimates the flgradient of the expected fitness by using uniform distribited variations and updates the centroid of the population through the Adam stochastic gradient optimizer
Categorical policies
Common stochastic policies used in the case of discrete action spaces, i.e. in problems where the agent can perform an action within a finite set of possible alternative actions.
Diagonal Gaussian Policies
Common stochastic policies used for problems involving a continuous action space.