title: Design of Spiking Central Pattern Generators for Multiple Locomotion Gaits in Hexapod Robots by Christiansen Grammar Evolution.
abstract: This paper presents a method to design Spiking Central Pattern Generators (SCPGs) to achieve locomotion at different frequencies on legged robots. It is validated through embedding its designs into a Field-Programmable Gate Array (FPGA) and implemented on a real hexapod robot. The SCPGs are automatically designed by means of a Christiansen Grammar Evolution (CGE)-based methodology. The CGE performs a solution for the configuration (synaptic weights and connections) for each neuron in the SCPG. This is carried out through the indirect representation of candidate solutions that evolve to replicate a specific spike train according to a locomotion pattern (gait) by measuring the similarity between the spike trains and the SPIKE distance to lead the search to a correct configuration. By using this evolutionary approach, several SCPG design specifications can be explicitly added into the SPIKE distance-based fitness function, such as looking for Spiking Neural Networks (SNNs) with minimal connectivity or a Central Pattern Generator (CPG) able to generate different locomotion gaits only by changing the initial input stimuli. The SCPG designs have been successfully implemented on a Spartan 6 FPGA board and a real time validation on a 12 Degrees Of Freedom (DOFs) hexapod robot is presented.
authors: Leon Institute of Technology , Leon , Mexico.
authors: Andres
authors: A
authors: Espinal
authors: Department of Electronics, DICIS-University of Guanajuato , Salamanca , Mexico.
authors: Horacio
authors: H
authors: Rostro-Gonzalez
authors: Leon Institute of Technology , Leon , Mexico.
authors: Martin
authors: M
authors: Carpio
authors: Department of Electronics, DICIS-University of Guanajuato , Salamanca , Mexico.
authors: Erick I
authors: EI
authors: Guerra-Hernandez
authors: Leon Institute of Technology , Leon , Mexico.
authors: Manuel
authors: M
authors: Ornelas-Rodriguez
authors: Department of Organizational Studies, División de Ciencias Economico-Administrativas-University of Guanajuato , Guanajuato , Mexico.
authors: Marco
authors: M
authors: Sotelo-Figueroa
keywords: Christiansen grammar evolution; FPGA; SPIKE-distance; central pattern generator; evolution strategy; legged robot locomotion; spiking neural network