%0 Journal Article %T Smooth control design for adaptive leader %A Jiangshuai Huang %A Ling Zhao %J Transactions of the Institute of Measurement and Control %@ 1477-0369 %D 2019 %R 10.1177/0142331218765309 %X In this paper, we investigate the distributed adaptive leader-following consensus control for high-order nonlinear multi-agent systems with a time-varying reference trajectory under directed topology, subjected to mismatched unknown parameters and unknown control directions. By introducing local estimators for the bounds of the reference trajectory and a filter for each agent, a new backstepping-based smooth distributed adaptive control protocol is proposed. Meanwhile, a Nussbaum-type function is applied to address the consensus control with unknown control directions. It is shown that global uniform boundedness of all the closed-loop signals and asymptotic output consensus tracking can be achieved. Simulation results are provided to verify the effectiveness of our scheme %K Adaptive control %K multi-agent systems %K time-varying reference %K unknown control directions %K nonlinear systems %U https://journals.sagepub.com/doi/full/10.1177/0142331218765309