Electromechanical actuator for a vehicle braking system, braking system and vehicle

Abstract

An electromechanical actuator (200) for a braking system of a vehicle (V), in particular a rail vehicle, is described, characterized in that it includes first control means (202) configured to receive speed signals from speed sensor means (204, 204') associated with the wheels (w) of the vehicle, the value of the speed signals being indicative of the angular velocity of the wheels (w) of the vehicle. A braking system and a vehicle are also described.

Description

[Technical field]

[0001] The present invention relates generally to the vehicle sector, and in particular the present invention relates to an electromechanical actuator for a braking system of a vehicle, a braking system and a vehicle. [Background technology]

[0002] In the prior art, typical solutions involve determining the forward speed of the vehicle based on the angular velocity of at least one of the wheels or an axle coupled to such wheels.

[0003] To prevent the determination of the forward speed of the vehicle from being corrupted by a wheel slip condition (i.e. a condition in which the forward speed of the vehicle is greater than a speed value given by multiplying the angular velocity of a wheel by the radius of that wheel) or a locked condition (i.e. a condition in which the angular velocity of a wheel is approximately zero even when the vehicle is moving), the determination of the forward speed of the vehicle may be obtained based on multiple angular velocities obtained from multiple wheels.

[0004] Knowing the forward speed of a vehicle is extremely important.

[0005] For example, knowing the forward speed of the vehicle and the angular speed of one or more wheels makes it possible to determine the wheel slip condition. In the prior art, a number of functions are known for managing wheel skip.

[0006] In the prior art, as can be seen for example in FIG. 1, the angular velocity of each wheel w to be monitored can be obtained starting from a respective speed sensor means 100 arranged to measure the angular velocity value of the respective wheel w.

[0007] The speed signal generated by this speed sensor means 100 is transferred to at least one central / control unit 102 on board the vehicle v.

[0008] This central unit / control unit 102 is mounted on the vehicle and is far away from the speed sensor means 100 and the wheels w. The speed signal is therefore transmitted by the speed sensor means 100 to said central unit / control unit 102 mounted on the vehicle by a long cable 101. This embodiment is particularly relevant for large vehicles, e.g. rail cars or rail convoys.

[0009] Using a long cable 101 presents at least the following problems: · Design issues regarding the definition of cable configurations within the vehicle Problems related to the fact that it is very difficult to lay cables along the vehicle High design and installation costs Long cables carrying weak analog signals are prone to disturbances, and therefore expensive shielded cables must be used, as the speed signal carries very important data and also affects vehicle safety.

[0010] With reference for example to rail transport systems, the fact that the control means, to which the speed signals obtained from the sensor means coupled to the wheels must be transmitted, are mounted on the train and therefore far away from the speed sensor means also owes to the fact that the most used known braking systems are pneumatic systems, since they are extremely safe. These pneumatic systems generate the braking force using compressed air, suitably injected into brake cylinders. This compressed air is generated by one or more compressors.

[0011] Disadvantageously, in pneumatic braking systems the element closest to the speed sensor is a pneumatic element without electronic control means, e.g. a pneumatic cylinder, etc. Therefore, also in the field of rail vehicles, the speed signal is transmitted by the speed sensor means by a long cable to said central / control unit mounted on the vehicle.

[0012] However, the techniques for generating compressed air are known to have several drawbacks. The overall efficiency of the compressor is very low, less than 50%, which translates into a huge consumption of non-recoverable energy. The compressor is a source of noise to both the passenger-occupied and external environments and requires significant soundproofing measures. The compressor is a source of vibration that is transmitted to the vehicle body, causing additional vibration and noise in the passenger occupied environment. The compressor, its supporting frame and soundproof enclosure for passive noise reduction represent huge masses, amounting to several hundred kilograms, and constitute a further energy inefficiency when calculating the energy required to accelerate a rail vehicle. Compressors have relatively frequent, intrusive and especially expensive maintenance cycles.

[0013] Compressed air braking systems further require the use of dryers to remove moisture from the compressed air, which are characterized by frequent, intrusive and expensive maintenance cycles. Additionally, compressed air braking systems require a reservoir for storing the compressed air and pipes for distributing the compressed air. Both the tank and the pipes represent additional cost, bulk and weight.

[0014] Thus, a known alternative solution to current concept pneumatic braking systems is represented by the use of electromechanical actuators to replace the current compressed air actuators.

[0015] Currently, exemplary electromechanical actuators generally include one or more electric motors that are incorporated into the electromechanical actuator itself, and the motor(s) serve, for example, two functions: Braking force application and release function, and and a mechanical element capable of performing one or more of the following functions: loading a spring with a sufficient amount of energy to apply at least one autonomous braking in case of loss of electrical energy or in case of emergency braking being required, which is necessary because electronic control of the motor(s) is not considered sufficiently safe. Summary of the Invention [Problem to be solved by the invention]

[0016] The object of the present invention is therefore to provide a solution that allows the transmission of speed signals coming from speed sensor means associated to the wheels of the vehicle to the control means over wiring that is as short as possible, keeping the design difficulties of such wiring low and obtaining a clean speed signal that is more resistant to any disturbances / interference. [Means for solving the problem]

[0017] The above and other objects and advantages are achieved according to one aspect of the present invention by an electromechanical actuator having the characteristics defined in claim 1, a braking system having the characteristics defined in claim 13, and a vehicle having the characteristics defined in claim 14. Preferred embodiments of the invention are defined in the dependent claims, the content of which is to be understood as an integral part of this description.

[0018] In summary, the invention is based on taking advantage of the presence of electromechanical actuators installed close to the wheels of a vehicle and including at least one electronic control means therein. The location of the electromechanical actuators relative to the wheels and the fact that they include at least one electronic control means that the electromechanical actuators can be advantageously used to receive speed signals coming from sensor means coupled to such wheels.

[0019] The functional and structural features of some preferred embodiments of an electromechanical actuator, a braking system and a vehicle according to the invention will now be described with reference to the accompanying drawings. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 shows a diagram of a solution implemented according to the prior art. [Figure 2a]FIG. 2a shows an embodiment of an electromechanical actuator according to the present invention. [Figure 2b] FIG. 2b shows another embodiment of an electromechanical actuator according to the invention. [Diagram 3] FIG. 3 illustrates yet another embodiment of an electromechanical actuator according to the present invention. [Figure 4] FIG. 4 illustrates an embodiment of a braking system according to the present invention. [Diagram 5] FIG. 5 is a diagram showing an embodiment of a vehicle according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Before describing several embodiments of the invention in detail, it should be made clear that the invention is not limited in its application to the details of design and the arrangement of components set forth in the following description or illustrated in the drawings. The invention contemplates other embodiments and may actually be implemented or constructed in different ways. It is also to be understood that the phraseology and terminology are for purposes of description and should not be construed as limiting. The use of "include" and "comprise" and variations thereof is intended to cover the elements set forth below and their equivalents, as well as additional elements and their equivalents.

[0022] In a first embodiment, as shown by way of example in FIG. 2a, an electromechanical actuator 200 for a braking system of a vehicle v, in particular a railway vehicle, comprises a first control means 202 configured to receive a speed signal from speed sensor means 204, 204' associated with a wheel w of the vehicle, the speed signal having a value indicative of the angular velocity of said wheel w of said vehicle.

[0023] In other words, the value of the speed signal is indicative of the angular velocity of the wheel w of the vehicle. For example, the value of the speed signal indicative of the angular velocity of the wheel may be, for example, a signal frequency value or an amplitude value.

[0024] For example, preferably, the first control means 202 of the electromechanical actuator 200 may be a control means further configured to manage the conversion of the electrical control signal into a corresponding braking force applied by the electromechanical actuator. Alternatively, preferably, the first control means 202 may be any suitable control means provided to perform any suitable function related to the received velocity signal, independent of converting the electrical control signal into a corresponding braking force applied by the electromechanical actuator 200. In further examples, without being limited to the examples described here, the first control means 202 may also be configured to perform other functions related to the generation / control of the braking force generated by the electromechanical actuator 200.

[0025] Preferably, the speed sensor means 204' may be included directly in the electromechanical actuator 200. In other words, the speed sensor means may be integrated into the electromechanical actuator.

[0026] Alternatively, and preferably, the speed sensor means 204 may be associated with the electromechanical actuator 200. For example, the speed sensor means may be external to the electromechanical actuator but associated / connected to the speed sensor means via a connection means. Preferably, this connection means may be a wired or wireless connection means. For interference reasons, a shielded cable may still be used for the wired connection. Advantageously, and unlike the prior art, the length of the cable may be reduced to a minimum due to the proximity of the speed sensor means and the wheels to the electromechanical actuator.

[0027] Preferably, the velocity sensor means 204, 204' may be an angular velocity sensor.

[0028] Preferably, the speed sensor means 204, 204' may be arranged to generate a speed signal as a function of the angular velocity of a phonic wheel associated with said wheel w of the vehicle.

[0029] As can be seen in Fig. 2b, in one embodiment, the electromechanical actuator 200 may be configured to transmit the velocity signal received (i.e., incoming) from the velocity sensor means to the second control means 206. Alternatively, the electromechanical actuator 200 may be configured to transmit the angular velocity value indicated by the velocity signal received (i.e., incoming) from the velocity sensor means 204, 204' to the second control means mounted on the vehicle. In this second case, for example, the first control means may derive the angular velocity value indicated by the received velocity signal and transmit the derived angular velocity value directly to the second control means.

[0030] Preferably, the second control means 206 may be configured to adjust the value of the braking force generated by said electromechanical actuator 200 .

[0031] For example, the second control means 206 may be a control means responsible for controlling the electromechanical actuator and the associated braking force. By way of example, the second control means may receive a control signal indicative of a control given by a driver of the vehicle or a control signal coming from an automatic control system installed on board the vehicle. The automatic control system may for example be an automatic driving system.

[0032] Preferably, the first control means 202 and / or the second control means 206 may be or include at least one of a microprocessor, a processor, a microcontroller, a controller, a PLC, an FPGA, a control unit, a control system or a control device.

[0033] Preferably, the second control means 206 may be configured to perform an anti-skid function of the wheels w of the vehicle. The anti-skid function may be configured to determine that a wheel is slipping as a function of the speed signal values ​​received by the second control means or the angular velocity values ​​received by the second control means. In the context of the present invention, the anti-skid function may be any anti-skid function known in the vehicle industry.

[0034] In other words, the electromechanical actuator 200 may transfer the velocity signal or the angular velocity value indicated by the velocity signal to the second control means 206 which will be in charge of managing the anti-skid function.

[0035] In a further embodiment, when the first control means transmits a speed signal received (i.e. incoming) from the speed sensor means 204, 204' to the second control means 206, the second control means 206 may be configured to provide a vehicle linear speed estimate determined based on the value of such speed signal. In this case, the first control means 202 may also receiving an estimated linear vehicle speed; -The estimated vehicle linear speed determines that the wheels are slipping, Implementing the anti-skid function of the vehicle's wheels when it determines that the wheels are slipping; It may be configured as follows.

[0036] Alternatively, when the first control means transmits the angular velocity value indicated by the received velocity signal to the second control means, the second control means may be configured to provide a vehicle linear velocity estimate determined based on the received angular velocity value. receiving the vehicle linear speed estimate; determining that a wheel w is slipping from the vehicle linear speed estimate; Executing the anti-skid function of the vehicle's wheels when it determines that the wheel w is slipping; It may be further configured as follows.

[0037] In other words, the electromechanical actuator 200 may forward the speed signal or the angular velocity value indicated by the received speed signal to the second control means 206 which will be in charge of estimating the forward speed of the vehicle. In one example, the second control means 206 will be able to receive speed signals or angular velocity values ​​also from further electromechanical actuators associated with the respective wheels. In this way, the estimate of the forward speed of the vehicle may be more accurate and reliable, since it is derived from the angular velocities of the wheels of the vehicle. The second control means 206 will then be able to forward the forward speed estimate to the first control means 202 which manages the anti-skid function. Thus, each electromechanical actuator 200 may be in charge of managing the anti-skid of the wheel with which it is associated. This aspect has the further advantage of having a distributed management of the anti-skid function. Having a distributed management of the anti-skid function allows that even if an electromechanical actuator is no longer able to perform its anti-skid function, the other actuators can continue to perform their anti-skid function autonomously, so as to ensure a high availability and safety of the management of the anti-skid function. Also in this case, the anti-skid feature may be any anti-skid feature known in the vehicle industry.

[0038] 3, the electromechanical actuator 200 may include a communication means 300 or may be associated with a communication means 300'. In this case, the electromechanical actuator 200 may be configured to transmit a velocity signal received (i.e., incoming) from the velocity sensor means to the cloud 302 or the ground station 304 via said communication means. Alternatively, the electromechanical actuator 200 may be configured to transmit an angular velocity value indicated by a velocity signal received (i.e., incoming) from the velocity sensor means 204, 204' to the ground station 304 or the cloud 302 via the communication means 300, 300'.

[0039] Preferably, the communication means 300, 300' may be a wireless communication means, for example, the communication means 300, 300' may include at least one Bluetooth communication device or a wireless communication device or the like.

[0040] Preferably, the electromechanical actuator 200 may include an energy storage means configured to store energy. The energy stored in the energy storage means may be sufficient to operate the electromechanical actuator to cause the braking system to perform at least one emergency braking operation or a service or parking operation.

[0041] The release of the energy stored in the energy storage means may be controlled as a function of the value of the speed signal received by the electromechanical actuator from the speed sensor means, for example the release of the energy stored in the energy storage means may be controlled by the first control means, or by the second control means, or by a further dedicated control means associated with the energy storage means.

[0042] Preferably the energy storage means comprises: Flywheel, Supercapacitors, Battery, Springs, may include at least one of the following:

[0043] The present invention also relates to a braking system. As can be seen from the example of FIG. 4, in one embodiment, the braking system 400 includes: an electromechanical actuator 200 according to any one of the previous embodiments, braking means configured to be actuated by said electromechanical actuator 200; Includes.

[0044] Preferably, the braking means includes or may be an air brake, an electro-pneumatic brake, an electro-mechanical brake, an electromagnetic brake, a magnetic brake, a friction brake or any type of brake that may be used on a vehicle.

[0045] In yet another aspect, the present invention relates to a vehicle. As can be seen from the example of FIG. 5, in one embodiment, a vehicle 500 includes: At least one wheel; at least one speed sensor means arranged to generate a speed signal having a value indicative of the angular speed of said at least one wheel w; The braking system according to the above embodiment; Includes.

[0046] Preferably the vehicle may be a rail car or a rail convoy.

[0047] As mentioned above, the present invention may preferably be applied to at least one rail vehicle traveling on a rail track. For example, the vehicle referred to herein may be a locomotive, and the course / route may include the track on which the wheels of the locomotive roll. The embodiments described herein are not limited to vehicles on a rail track. For example, the vehicle may be an automobile, a truck (e.g., an on-highway semi-trailer truck, a mining truck, a timber truck, etc.), a motorcycle, etc., and the route may be a road or a trail.

[0048] The advantages achieved are that it allows the transmission of the speed signals coming from the speed sensor means associated with the wheels of the vehicle to the control means over wiring as short as possible, keeping the design difficulties of such wiring low and providing a solution to obtain a clean speed signal that is more resistant to any disturbances / interference.

[0049] Various aspects and embodiments of the electromechanical actuator, braking system and vehicle according to the invention have been described. It is understood that each embodiment may be combined with any other embodiment. Furthermore, the invention is not limited to the described embodiments, but may be modified within the scope defined by the appended claims.

Claims

1. An electromechanical actuator (200) for a braking system of a vehicle (V), in particular a rail vehicle, comprising:

1. An electromechanical actuator (200), comprising: first control means (202) configured to receive a speed signal from a speed sensor means (204, 204') associated with the wheel (w) of the vehicle, the speed signal having a value indicative of the angular velocity of the wheel (w) of the vehicle.

2. the velocity sensor means (204') is included in the electromechanical actuator (200), or The electromechanical actuator (200) of claim 1, wherein the speed sensor means (204) is associated with the electromechanical actuator (200).

3. 3. The electromechanical actuator (200) of claim 1 or claim 2, wherein said velocity sensor means (204, 204') is an angular velocity sensor.

4. 4. The electromechanical actuator (200) of claim 1, wherein the speed sensor means (204, 204') is configured to generate the speed signal as a function of the angular velocity of a phonic wheel associated with the wheel (w) of the vehicle.

5. The electromechanical actuator comprises: transmitting said speed signal received from said speed sensor means (204, 204') to a second control means (206) installed in said vehicle; or transmitting the value of the angular velocity indicated by the velocity signal received from the velocity sensor means (204, 204') to a second control means (206) installed in the vehicle; The electromechanical actuator (200) according to any one of claims 1 to 4, comprising:

6. 6. The electromechanical actuator (200) of claim 5, wherein the second control means (206) is configured to adjust a value of the braking force generated by the electromechanical actuator (200).

7. the second control means (206) is configured to perform an anti-skid function for the wheels of the vehicle; 7. The electromechanical actuator (200) of claim 5 or claim 6, wherein the anti-skid function is configured to determine that the wheel (w) is slipping as a function of the speed signal received by the second control means (206) or the value of the angular velocity received by the second control means (206).

8. when the first control means transmits the speed signal received from the speed sensor means to the second control means (206), the second control means (206) being configured to provide a vehicle linear speed estimate determined based on the value of the speed signal; The first control means (202) receiving the vehicle linear speed estimate; determining from the vehicle linear speed estimate that the wheel (w) is slipping; executing an anti-skid function of said wheel of said vehicle when said first control means (202) determines that said wheel (w) is slipping. further comprising: Or, when the first control means transmits the value of the angular velocity indicated by the received speed signal to the second control means (206), the second control means (206) is configured to provide a vehicle linear velocity estimate determined based on the received value of the angular velocity; The first control means (202) receiving the vehicle linear speed estimate; determining from the vehicle linear speed estimate that the wheel (w) is slipping; executing an anti-skid function of said wheel of said vehicle when said first control means (202) determines that said wheel (w) is slipping. further comprising:

7. An electromechanical actuator (200) according to claim 5 or claim 6.

9. Electromechanical actuator (200) according to any of the preceding claims, wherein said electromechanical actuator comprises communication means (300) or is associated with communication means (300').

10. The electromechanical actuator (200) transmitting the speed signal received from the speed sensor means (204, 204') to a ground station (304) or a cloud (302) via the communication means (300, 300'); Or, transmitting the value of the angular velocity indicated by the velocity signal received from the velocity sensor means (204, 204') to a ground station (304) or a cloud (302) via the communication means (300, 300'); The electromechanical actuator (200) of claim 9, configured to:

11. an energy storage means configured to store energy; The energy stored in the energy storage means activating the electromechanical actuator to cause the braking system to perform at least one emergency braking operation, a service operation, or a parking operation; The electromechanical actuator (200) of any of claims 1 to 10, which is sufficient for

12. The energy storage means Flywheel, supercapacitor, battery and spring, The electromechanical actuator (200) of claim 11, comprising at least one of:

13. An electromechanical actuator (200) according to any one of claims 1 to 12, a braking means (402) configured to be actuated by said electromechanical actuator (200); A braking system (400).

14. At least one wheel (w); at least one speed sensor means (204, 204') configured to generate a speed signal having a value indicative of the angular speed of said at least one wheel (w); A braking system (400) according to claim 13; Including, vehicles.

15. 15. The vehicle of claim 14, wherein the vehicle is a rail car or a rail convoy.

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