  The guidance of a torpedo represents a hard task because of the smooth
nonlinear aspect of this system and because of the extreme external
disturbances. The torpedo guidance reposes on the speed and the position
control. In fact, the control approach which is very solicited for the
electromechanical systems is the sliding mode control (SMC) which proved its
effectiveness through the different studies. The SMC is robust versus
disturbances and model uncertainties; however, a sharp discontinuous control is
needed which induces the chattering phenomenon. The angular velocity
measurement is a hard task because of the high level of disturbances. In this
way, the sliding mode observer could be a solution for the velocity estimation
instead of a sensor. This article deals with torpedo guidance by SMC to reach
the desired path in a short time and with high precision quality. Simulation
results show that this control strategy and observer can attain excellent
control performances with no chattering problem.
