%0 Journal Article %T Output consensus of nonlinear multi-agent systems with unknown control directions %A Yutao Tang %J Mathematics %D 2015 %I arXiv %R 10.14736/kyb-2015-2-0335 %X In this paper, we consider an output consensus problem for a general class of nonlinear multi-agent systems without a prior knowledge of the agents' control directions. Two distributed Nussbaumtype control laws are proposed to solve the leaderless and leader-following adaptive consensus for heterogeneous multiple agents. Examples and simulations are given to verify their effectiveness %U http://arxiv.org/abs/1508.03177v1