Robust position synchronized tracking by a bounded distributed control without velocity measurements

An existing bounded controller for position synchronized tracking without velocity measurements is improved in this paper. To attenuate the effect of uncertainty and disturbance involved in system dynamics, an uncertainty and disturbance estimator (UDE) is embedded in the existing bounded tracker by which the nominal closed-loop system is globally asymptotically stable. Then, the conditions ensuring zero-error tracking for each agent are identified. For the general cases with non-zero tracking errors, we show that the obtained error system is both small-signal L
_∞
stable and locally input-to-state stable. Finally, simulation results are provided to illustrate the effectiveness of the presented control scheme.