Abstract: In the standard particle swarm optimization(PSO),the premature convergence of particles and slow convergence in the late process decrease the searching ability of the algorithm.By introducing the hybrid mutation mechanism,an immunity cloning PSO (ICPSO)algorithm was proposed and applied to the wave impedance inversion problem.When the local extremum is close to the global extremum,the proposed cloning selection operator can accelerate the best particle away form the local extremum. On the other hand,when the local extremum is far away from the global extremum,Tent sequence is adopted to extend the search scope and further the best particle mutation.Simulation for wave impedance inversion indicates that IPSO has better efficiency and higher accuracy.

Key words: Particle swarm optimization,Immune particle swarm optimization,Immune cloning,Wave impedance inversion