This thesis complies the designing of an algorithm of automatic guidance for a four wheel steering (4WS) unmanned ground vehicle (UGV) within the framework of agriculture 4.0. The 4WS is obtained by implementing two Ackermann steering mechanisms (ASM) on both front and rear axes: such mechanism generates wheels' slippage whenever both axles are steered.\\ The main purpose of the thesis is to design a controller able to pursue the automatic guidance on a given path and in the meantime optimize the velocities of each wheel in order to minimize the slippage produced by the ASM.\\ On the other hand, a simulation environment has been designed to study behaviour of the vehicle.