On-line energy management for HEV based on particle swarm optimization S. Caux, D. Wanderley-Honda, D. Hissel and M. Fadel Eur. Phys. J. Appl. Phys., 54 2 (2011) 23403 Published online: 19 May 2011 DOI: 10.1051/epjap/2010100248