A vehicle control system including human-control members generating signals for manual piloting of actuators of the vehicle, an automatic control module generating signals for automatic piloting of the actuators of the vehicle, and a switching module to select the manual-piloting signals in a manual mode of operation and the autonomous-piloting signals in an autonomous mode of operation. The automatic control module includes a block for automatic formulation of at least one calculated autonomous piloting signal and a security block to transmit to the switching module a calculated autonomous piloting signal in a case of normal autonomous operation and an emergency autonomous piloting signal in a case of abnormal autonomous operation.