2,743 research outputs found
Neural network controller against environment: A coevolutive approach to generalize robot navigation behavior
In this paper, a new coevolutive method, called Uniform Coevolution, is introduced to learn weights of a neural network controller in autonomous robots. An evolutionary strategy is used to learn high-performance reactive behavior for navigation and collisions avoidance. The introduction of coevolutive over evolutionary strategies allows evolving the environment, to learn a general behavior able to solve the problem in different environments. Using a traditional evolutionary strategy method, without coevolution, the learning process obtains a specialized behavior. All the behaviors obtained, with/without coevolution have been tested in a set of environments and the capability of generalization is shown for each learned behavior. A simulator based on a mini-robot Khepera has been used to learn each behavior. The results show that Uniform Coevolution obtains better generalized solutions to examples-based problems.Publicad
An enhanced classifier system for autonomous robot navigation in dynamic environments
In many cases, a real robot application requires the navigation in dynamic environments. The navigation problem involves two main tasks: to avoid obstacles and to reach a goal. Generally, this problem could be faced considering reactions and sequences of actions. For solving the navigation problem a complete controller, including actions and reactions, is needed. Machine learning techniques has been applied to learn these controllers. Classifier Systems (CS) have proven their ability of continuos learning in these domains. However, CS have some problems in reactive systems. In this paper, a modified CS is proposed to overcome these problems. Two special mechanisms are included in the developed CS to allow the learning of both reactions and sequences of actions. The learning process has been divided in two main tasks: first, the discrimination between a predefined set of rules and second, the discovery of new rules to obtain a successful operation in dynamic environments. Different experiments have been carried out using a mini-robot Khepera to find a generalised solution. The results show the ability of the system to continuous learning and adaptation to new situations.Publicad
A general learning co-evolution method to generalize autonomous robot navigation behavior
Congress on Evolutionary Computation. La Jolla, CA, 16-19 July 2000.A new coevolutive method, called Uniform Coevolution, is introduced, to learn weights for a neural network controller in autonomous robots. An evolutionary strategy is used to learn high-performance reactive behavior for navigation and collision avoidance. The coevolutive method allows the evolution of the environment, to learn a general behavior able to solve the problem in different environments. Using a traditional evolutionary strategy method without coevolution, the learning process obtains a specialized behavior. All the behaviors obtained, with or without coevolution have been tested in a set of environments and the capability for generalization has been shown for each learned behavior. A simulator based on the mini-robot Khepera has been used to learn each behavior. The results show that Uniform Coevolution obtains better generalized solutions to example-based problems
The 1990 progress report and future plans
This document describes the progress and plans of the Artificial Intelligence Research Branch (RIA) at ARC in 1990. Activities span a range from basic scientific research to engineering development and to fielded NASA applications, particularly those applications that are enabled by basic research carried out at RIA. Work is conducted in-house and through collaborative partners in academia and industry. Our major focus is on a limited number of research themes with a dual commitment to technical excellence and proven applicability to NASA short, medium, and long-term problems. RIA acts as the Agency's lead organization for research aspects of artificial intelligence, working closely with a second research laboratory at JPL and AI applications groups at all NASA centers
Applying classifier systems to learn the reactions in mobile robots
The navigation problem involves how to reach a goal avoiding obstacles in dynamic environments. This problem can be faced considering reactions and sequences of actions. Classifier systems (CSs) have proven their ability of continuous learning, however, they have some problems in reactive systems. A modified CS, namely a reactive classifier system (RCS), is proposed to overcome those problems. Two special mechanisms are included in the RCS: the non-existence of internal cycles inside the CS (no internal cycles) and the fusion of environmental message with the messages posted to the message list in the previous instant (generation list through fusion). These mechanisms allow the learning of both reactions and sequences of actions. This learning process involves two main tasks: first, discriminate between rules and, second, the discovery of new rules to obtain a successful operation in dynamic environments. DiVerent experiments have been carried out using a mini-robot Khepera to find a generalized solution. The results show the ability of the system for continuous learning and adaptation to new situations.Publicad
Coevolutive adaptation of fitness landscape for solving the testing problem
IEEE International Conference on Systems, Man, and Cybernetics. Nashville, TN, 8-11 October 2000A general framework, called Uniform Coevolution, is introduced to overcome the testing problem in evolutionary computation methods. This framework is based on competitive evolution ideas where the solution and example sets are evolving by means of a competition to generate difficult test beds for the solutions in a gradual way. The method has been tested with two different problems: the robot navigation problem and the density parity problem in cellular automata. In both test cases using evolutive methods, the examples used in the learning process biased the solutions found. The main characteristics of the Uniform Coevolution method are that it smoothes the fitness landscape and, that it obtains âideal learner examplesâ. Results using uniform coevolution show a high value of generality, compared with non co-evolutive approaches
Simulation of Rapidly-Exploring Random Trees in Membrane Computing with P-Lingua and Automatic Programming
Methods based on Rapidly-exploring Random Trees (RRTs) have been
widely used in robotics to solve motion planning problems. On the other hand, in the
membrane computing framework, models based on Enzymatic Numerical P systems
(ENPS) have been applied to robot controllers, but today there is a lack of planning
algorithms based on membrane computing for robotics. With this motivation, we
provide a variant of ENPS called Random Enzymatic Numerical P systems with
Proteins and Shared Memory (RENPSM) addressed to implement RRT algorithms
and we illustrate it by simulating the bidirectional RRT algorithm. This paper is an
extension of [21]a. The software presented in [21] was an ad-hoc simulator, i.e, a tool
for simulating computations of one and only one model that has been hard-coded.
The main contribution of this paper with respect to [21] is the introduction of a novel
solution for membrane computing simulators based on automatic programming. First,
we have extended the P-Lingua syntax âa language to define membrane computing
modelsâ to write RENPSM models. Second, we have implemented a new parser based
on Flex and Bison to read RENPSM models and produce source code in C language
for multicore processors with OpenMP. Finally, additional experiments are presented.Ministerio de EconomĂa, Industria y Competitividad TIN2017-89842-
Genetic learning of fuzzy reactive controllers
P. 33-41This paper concerns the learning of basic behaviors in an autonomous robot. It presents a method to adapt basic reactive
behaviors using a genetic algorithm. Behaviors are implemented as fuzzy controllers and the genetic algorithm is used to
evolve their rules. These rules will be formulated in a fuzzy way using prefixed linguistic labels. In order to test the rules
obtained in each generation of the genetic evolution process, a real robot has been used. Numerical results from the evolution
rate of the different experiments, as well as an example of the fuzzy rules obtained, are presented and discussedS
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