Brake-by-wire braking system for vehicles, provided with electric actuation and electric back-up

1 . A braking system for vehicles comprising

a first brake group, a second brake group and a third brake group,

each brake group comprising a rotor, a braking device associated with said rotor, and an electro-hydraulic or electromechanical actuator of each braking device,

a first and a second control unit for said brake groups,

wherein the first control unit is operatively connected to the first brake group by a first piloting device for said electromechanical or electro-hydraulic actuator of the first brake group,

wherein the second control unit is operatively connected to the second brake group by a second piloting device for said electromechanical or electro-hydraulic actuator of the second brake group, and is connected to the third brake group by a third piloting device for the electromechanical or electro-hydraulic actuator of the third brake group,

wherein the first control unit is connected to and powered by a first power source, and wherein the second control unit is connected to and powered by a second power source, said first and second power sources being independent and galvanically isolated from each other,

each control unit being programmed to implement, via the corresponding piloting system, a standard braking strategy in case of malfunctions for each brake group and a fault braking strategy, if it detects an electrical fault of one or more of the brake groups,

wherein the braking system comprises a first and a second manual actuation device for a request for a braking action by a user, wherein both the manual actuation devices are each provided with exactly two separate actuation sensors,

wherein the exactly two actuation sensors each consist of (i) a first actuation sensor electrically coupled only to the first control unit and (ii) a second actuation sensor electrically coupled only to the second control unit,

wherein the first sensor and second sensor are on different signal paths corresponding to the galvanically isolated first and second power sources.

2 . The vehicle braking system according to claim 1 , wherein each control unit is connected to said first and second power sources so that it can be alternately powered by each of said power sources in the event of a fault of one of them.

3 . The vehicle braking system according to claim 2 , wherein an additional control unit or a dedicated electrical circuit programmed to manage the power supply of each control unit is provided.

4 . The braking system according to claim 1 , wherein each piloting device is programmed to switch from a first switch position, corresponding to the standard braking strategy, to a second switch position corresponding to the fault-braking strategy.

5 . The vehicle braking system according to claim 1 , wherein each electromechanical or electro-hydraulic actuator is equipped with an operating sensor suitable to monitor the operating condition of the relative electromechanical or electro-hydraulic actuator and/or of the relative braking device and to send the corresponding control unit an indication of standard or fault operation.

6 . The vehicle braking system according to claim 1 , wherein the control units are programmed so that in case of fault of one of the first brake group, the second brake group, or the third brake group, the actuation of the remaining brake groups is ensured and coordinated.

7 . The vehicle braking system according to claim 1 , wherein the control units are programmed so that in the event of a fault of one of the first brake group, the second brake group, or the third brake group, the actuation of the remaining brake groups is ensured and coordinated, wherein the braking system is operatively connected to an electricity generating device operatively connected to the brake groups so as to obtain an additional braking action of the vehicle.

8 . The vehicle braking system according to claim 4 , wherein each electromechanical or electro-hydraulic actuator is equipped with two operating sensors, each suitable to monitor the operating condition of the relative electromechanical or electro-hydraulic actuator and/or of the relative braking device and to send an indication of standard or fault operation to both the control units.

9 . The vehicle braking system according to claim 1 , wherein the system is managed by a control unit of the vehicle which manages vehicle dynamics and is able to perform guidance and an independent braking action of the same.

10 . The vehicle braking system according to claim 1 , wherein at least two of said brake groups are associated with a first vehicle wheel and wherein the third brake group is associated with a second vehicle wheel, distinct from the first wheel.

11 . The vehicle braking system according to claim 1 , wherein each of said first, second and third brake groups is associated with a respective and distinct wheel of a vehicle.

12 . The vehicle braking system according to claim 1 , wherein the first control unit determines the braking request based only on data from the first actuation sensors.

13 . The vehicle braking system according to claim 1 , wherein the second control unit determines the braking request based only on data from the second actuation sensors.

14 . The vehicle braking system according to claim 1 , wherein each sensor sends data to only one control unit.

15 . The vehicle braking system according to claim 1 , wherein each control unit receives data from only two sensors.

16 . The vehicle braking system according to claim 1 , wherein the first control unit and the second control unit determine a braking request independently from one another.