Artificial force in robust control of mobile manipulator application

In the paper mobile manipulator using skid steering platform, has been considered. Such system is underactuated. This paper presents the concept of artificial force applied in robust control an discussion of obtained results. Artificial force concept assumes full rank of input matrix, describing relationships between controlled variables and number of actuators. Despite of assumption that the additional actuator signal is identically equal to zero, the invertibility of the input matrix is achieved. This signal is used to generate reference signal, needed in control algorithm. Mathematical proof of proper action of such a control law has been presented using Lyapunov-like function. Usefulness of this concept, under the assumption of parametric uncertainty of the terrain as well as in order to track inadmissible trajectories, has been verified in numerous simulations.