Hydraulic closed circuit motorization system and method for controlling the driving of a transport vehicle

A hydraulic closed circuit motorization system for controlling the driving of a transport vehicle comprising bodies rolling on the ground;

• the hydraulic system comprising at least one variable-displacement pump for sending an operating fluid in a delivery branch and receiving the operating fluid from a return branch of the system, at least one motor for driving the main pump, a plurality of hydraulic motors connected to the delivery branch and to the return branch and actuating said rolling bodies and a general command and control unit for controlling said pump and said hydraulic motors in an ordinary advancing condition of the vehicle and moving the vehicle along a pre-planned advance route;
• characterized in that it furthermore comprises a hydraulic emergency command and control unit comprising:
• a pressure detection means for detecting the pressure of the delivery branch and of the return branch and for outputting respective electric signals;
• an emergency solenoid valve interposed between said delivery branch and said return branch;
• and
• a command and control unit in emergency conditions configured to receive said electric signals from said pressure detecting means and to switch the solenoid valve between an open position in which it directly connects the delivery branch with the return branch, and a closed position in which it hydraulically isolates the delivery branch and the return branch;
• said command and control unit in emergency conditions comprising:
• a first computation means for calculating the difference between the delivery pressure and the return pressure;
• a second computation means for calculating, during the advancing of the vehicle, an instantaneous first derivative as a function of the time of said pressure difference;
• a comparator means for comparing the instantaneous first derivative with a value of the first reference derivative;
• and
• an actuator means for commanding said solenoid valve to open when a deviation between the value of the instantaneous first derivative and the value of the first reference derivative occurs.