Accurate parking planning of Tractor-Trailer-Trailer mobile robot

Accurate parking planning strategies for Tractor-Trailer-Trailer (TTT) mobile robot are proposed in this paper. Restricted by the nonholonomic constraint, accurate parking planning for such driftless underactuated system is usually difficult. However, a local system coordinate transformation method provides an easily handled form, for whom, a time-varying continuous controller is utilized. Combined with an extra robust control law, this controller can reduce the oscillatory term, and keep all the state variables asymptotically stable. Numeric simulation results are presented to verify this result.