Research On Fault-tolerant Circuits Evolution And Self-repair Technology Based On Improved Genetic Algorithm

Evolvable hardware is a hardware system which integrates the evolutionaryalgorithm with the reconfigurable hardware organically. The research of evolvablehardware has great practical and theoretical meaning on the realization of the adaptive andself-repair of new intelligent circuit and hardware system. The evolutionary design forcircuits and self-repairing system are two important research areas in the evolvablehardware field. Based on the circuit design of hardware evolution technology, this thesishas explored the following areas:After describing the principle and implementation method of circuit evolution, thisthesis maps the digital circuit topologies to artificial neural networks and builds the neuralnetwork model as well as the research of the matrix code operator for chromosomeencoding. All of this provides a foundation for the evolution and repair of the circuit.After describing the classification and characteristics of genetic algorithm, this thesisproposes an improved adaptive algorithm based on the phenomenon of rapidly growing ofthe fitness value in the earlier stage of the circuit evolution and slowly growing in the laterstage. The algorithm uses the roulette based on the cross-generational elitist mechanismand also combined with adaptive strategies together to ensure the speed of theconvergence and the global search. The introduction of the parallel mutations and theimprovement of speed of the convergence at the later stage of the circuit evolutionprovide algorithm foundation for the evolution and repair for the circuit.After the analysis of the circuit model and the features of the encoding structure, thisthesis devises the method of circuit fault quick diagnosis and fast reconstruction methodwhich based on redundant resources. For the fault which can be located, the bad unit canbe replaced by redundant one. However, for the circuits which can not be rapid repaired,the thesis proposes restoration circuit. This thesis constructs the experimental simulationplatform for evolution and restoration of circuit. On the basis of this, this thesis makes anexperiment about the evolution and restoration of a full adder and a two-bit full addermultiplier. The experimental results show that the realization of the evolution andrestoration of simple circuit is feasible by using evolvable hardware method.