Autonomous forklift truck control system and method for drivng the forklift truck

1. A control system for a lift truck vehicle, the control system being mounted on the lift truck vehicle and comprising:

human-control devices generating manual guidance signals for one or more actuators of the vehicle, the human-control devices including a hydraulic steering system;

a control module including an automatic-control submodule generating autonomous guidance signals intended for the one or more actuators of the lift truck vehicle, depending on setpoint signals;

a switching module designed to select one or more manual guidance signals generated by the human-control devices and/or one or more autonomous guidance signals generated by the automatic-control submodule;

an electrohydraulic valve enabling conversion of the one or more manual guidance signals and/or the one or more autonomous guidance signals into a signal intended for the hydraulic steering system; and

a servo controller of the electrohydraulic valve comprising a proportional-integral controller and an on/off controller, wherein the servo controller is configured to activate the proportional-integral controller when a speed of the lift truck vehicle is less than a speed threshold of the lift truck vehicle, the speed threshold being greater than zero, and activate the on/off controller when the speed of the lift truck vehicle is greater than the speed threshold.

2. The system according to claim 1 , wherein the speed threshold is fixed at 2 m/s.

3. The system according to claim 1 further comprising:

a detection module for detecting an environment of the lift truck vehicle; and

a navigation module generating guidance setpoint signals, depending on a received instruction,

wherein the control module includes an assisted-control submodule generating corrected manual guidance signals depending on the one or more manual guidance signals and on information from the detection module and/or on the guidance setpoint signals, and

wherein the switching module is designed to select corrected manual signals.

4. The system according to claim 3 , wherein the switching module selects the handling signals as a function of four operating modes:

a manual mode in which only the one or more manual guidance signals are selected;

a completely automatic mode in which only the one or more autonomous guidance signals are selected;

a manual mode with assisted security, in which the one or more manual guidance signals corrected by the information from the detection module are selected; and

a manual mode with assisted navigation, in which the one or more manual guidance signals corrected by the guidance set point signals are selected.

5. The system according to claim 3 , wherein the switching module can select a maintenance mode, in which all of the elements of the control system, with the exception of the human-control devices, are deactivated.

6. The system according to claim 3 , wherein the navigation module is configured to telecommunicate with a remote computer.

7. The system according to claim 6 , wherein the navigation module is configured to position of the lift truck vehicle to be known in real time.

8. The system according to claim 3 , wherein the guidance set point signals comprise a speed set point, a truck wheel angle of rotation set point, a fork elevation set point, a fork angle of inclination set point, and a fork separation set point.

9. The system according to claim 3 , wherein the detection module comprises a fork management submodule comprising:

sensors for detecting a presence of a load on forks; and

fork position sensors.

10. The system according to claim 9 , wherein the fork management sub-module is configured to detect an inconsistency relating to the load on the forks and for transmitting a stop signal in the event of any inconsistency.

11. The system according to claim 3 , wherein the detection module comprises a submodule for detecting protection zones comprising:

at least one laser to detect a presence of an obstacle in a zone surrounding the vehicle.

12. The system according to claim 1 , wherein the human-control devices are selected from the group consisting of an accelerator pedal, a brake pedal, a steering wheel, a vehicle direction of travel selector, and a lever for controlling lifting, inclination and separation of forks.

13. A lift truck vehicle comprising a control system according to claim 1 .