Electric brake assembly, computer-implemented method for controlling electric brake assembly, computer program and non-volatile data carrier

Abstract

An electric brake assembly for a rail vehicle includes: a rotating member mechanically coupled to an axle of the rail vehicle; at least one friction member, the at least one friction member being movable between an engaged position, in which the friction member contacts the rotating member, and a disengaged position, in which the rotating member is free to rotate; the gear assembly is used for carrying out mechanical operation on the friction component; a motor controlled via a control signal to cause the gear assembly to operate the friction member to move between the engaged position and the disengaged position; and a controller which is used for generating the control signal. When the control signal (710) is generated, the controller obtains a pulse count signal (720) and a pressure signal (730). The pulse count signal reflects an angular movement of an output shaft of the motor, and the pressure signal indicates a magnitude of force experienced in the gear assembly when the friction member is in the engaged position and / or the disengaged position. Based on the pressure and the pulse count signal, the controller checks whether an alarm criterion is satisfied with respect to wear of the friction member (740), and if so, triggers an alarm (750).

Description

Technical Field

[0001] The invention generally relates to monitoring of brake devices for rail vehicles. In particular, the invention relates to an electric brake assembly according to the preamble of claim 1 and a corresponding computer-implemented method. The invention also relates to a computer program and a non-volatile data carrier storing such a computer program. Background Art

[0002] When an electric rail vehicle is in operation, the on-board electric motor is usually used as a generator for decelerating the rail vehicle. However, for efficiency and safety reasons, this braking strategy cannot be relied upon exclusively. In particular, a dedicated braking function is always required to ensure emergency braking functionality and to ensure that the rail vehicle remains stationary after it has stopped. In many cases, the same brake unit is used for different types of braking functionality, such as service brake, emergency brake and parking brake.

[0003] Typically, a brake unit includes a rotating member mechanically coupled to the axle of a rail vehicle plus one or more friction members arranged to press against the rotating member to decelerate the rail vehicle. Specifically, contact between the friction material (i.e., the lining in a brake pad or brake shoe) and the rotating member (e.g., a disc or drum) creates a frictional contact that produces the desired amount of braking torque to slow the rail vehicle. Repeated braking operations gradually wear away the friction material, which causes the brake lining to gradually become thinner. Therefore, at some point in time, the friction material must be replaced.

[0004] Various solutions for monitoring the wear of brake linings are known in the art. For example, US Pat. No. 10,919,513 describes a device and a method for predicting the wear of brake linings of rail vehicles. Here, the lining thickness, sliding speed, contact pressure, total braking time and optionally the temperature or braking power are determined in a parameterization process during a test drive measured at predetermined time intervals. Wear, constants and material parameters are determined from this, wherein during the operating state, the wear rate and thus the wear are determined via the now known material parameters and constant values. The remaining total braking time before the next lining change is required is then determined based on the maximum permissible wear value. In order to determine the wear rate, the document studies the lining surface contact pressure, the sliding speed and the braking time and predicts the remaining service life of the brake lining on this basis. However, the lining thickness itself is not measured, and this makes the prediction uncertain.

[0005] US10,435,050 shows a method for monitoring and diagnosing components of a rail vehicle as a single rail vehicle or as part of a rail vehicle train consisting of multiple rail vehicles, with respect to necessary repair or maintenance of at least one component. At least one measuring device captures at least one measured variable, which is related to the assessment of necessary repair or maintenance of the component. The assessment device executes assessment software based on instructions, data and / or software modules sent from a control center. Specifically, it is proposed to detect the thickness of the lining by means of electrical circuits integrated in the brake lining, which are destroyed when the brake lining is worn to the lining layer in which these circuits are arranged. An electrical signal indicating the corresponding degree of wear is then generated. Although this design may be useful, it increases the cost and complexity of the brake lining. The electrical circuit also poses a risk of reducing braking efficiency.

[0006] Known solutions for monitoring rail vehicle brake lining wear are therefore associated with various technical drawbacks. Summary of the invention

[0007] The present invention aims to alleviate the above mentioned problems and provide a solution which continuously measures the wear of friction components during rail vehicle operation, provides advance notice of wear and enables timely replacement of friction components without compromising braking capability.

[0008] According to one aspect of the present invention, the object is achieved by an electric brake assembly for a rail vehicle. The brake assembly comprises: a rotating member, the rotating member being mechanically connected to the wheel axle of the rail vehicle; at least one friction member, the at least one friction member being movable between an engaged position and at least one disengaged position, in which the at least one friction member contacts the rotating member, and in which the at least one disengaged position, the rotating member is free to rotate without contacting the at least one friction member; a gear assembly, the gear assembly being arranged to mechanically operate the at least one friction member; a motor, the motor being controllable via a control signal and configured to cause the gear assembly to operate the at least one friction member to move between the engaged position and at least one disengaged position; and a controller, the controller being configured to generate a control signal. During the process of generating the control signal, the controller is configured to obtain a pulse count signal and a pressure signal. Each pulse count in the pulse count signal reflects a specific angular movement of the output shaft of the motor, and the pressure signal indicates the magnitude of the force experienced in the gear assembly when the at least one friction member is in the engaged position and / or at least one disengaged position. Based on the pressure and pulse count signals, the controller is configured to check whether an alarm criterion regarding wear of the at least one friction member is met. If the alarm criteria are met, the controller is configured to trigger an alarm.

[0009] The above electric brake assembly is advantageous because the pressure signal clearly links the pulse count signal to the precise mechanical relationship between the at least one friction member and the rotating member. This in turn ensures accurate and reliable monitoring of the wear of the at least one friction member, so that the friction member can be replaced in a timely and effective manner.

[0010] According to one embodiment of this aspect of the invention, the controller is configured to perform the following steps:

[0011] (a1) recording a first number of pulse counts obtained via the pulse count signal, and generating a control signal to control the motor to cause the gear assembly to operate the at least one friction member in an approach direction of the at least one friction member from the first disengaged position to the engaged position, and continuing to generate the control signal to control the motor to cause the gear assembly to operate the at least one friction member in the approach direction until the pressure signal exceeds a positive threshold,

[0012] (b1) comparing the first number of pulse counts with the base of the pulse counts recorded in the previous execution step, and if the base is lower than the first number,

[0013] (c1) increasing the wear count by the difference between the first number and the base number, and if the wear count exceeds the threshold count, then

[0014] (d1) Trigger an alarm.

[0015] The above-mentioned step-by-step recording of friction member wear provides the earliest possible indication of when replacement is required. That is, wear can be checked in conjunction with each braking operation.

[0016] Preferably, the first disengaged position represents an idle distance between the rotating member and the at least one friction member, the idle distance defining a predefined rest position of the at least one friction member between braking operations.Thus, the proposed wear monitoring can be combined with a fast response service brake.

[0017] According to another embodiment of this aspect of the invention, the controller is configured to perform the following steps:

[0018] (a2) generating a control signal to control the motor to operate the gear assembly so that the gear assembly retracts the at least one friction member from the rotating member in a retraction direction from the engaged position outwardly until the pressure signal drops below a negative threshold value, the negative threshold value indicating a maximum retraction of the at least one friction member from the rotating member, the maximum retraction indicating a second disengaged position,

[0019] (b2) recording a second number of pulse counts obtained via the pulse count signal when performing the steps, and if the second number exceeds a threshold count,

[0020] (c2) Trigger an alarm.

[0021] Thereby, where appropriate, for example before leaving a station, the rail vehicle may test the wear of the friction members against a fixed reference measurement represented by a maximum retraction of the at least one friction member.

[0022] According to another embodiment of this aspect of the invention, the motor is configured to generate a rotational force on the output shaft of the motor, the rotational force being proportional to the drive current fed to the motor. Here, the controller is configured to derive the pressure signal based on the drive current fed to the motor. Thus, the force sensor can be implemented, for example, in software running in the controller.

[0023] According to other embodiments of this aspect of the invention, alternatively, the gear assembly comprises a force sensor configured to generate a pressure signal, which may be arranged on a bolt in the gear assembly. The force sensor may in turn comprise a load cell or a wire strain gauge. This makes the implementation robust and straightforward.

[0024] According to another embodiment of this aspect of the invention, the electric motor is a stepper motor configured to generate a pulse count signal.Therefore, no separate component in the form of an angular position sensor is required to generate the pulse count signal.

[0025] Alternatively, the angular position sensor can be a separate component from the motor, the sensor being contained, for example, in a bevel gear connecting the output shaft of the motor with the gear assembly. Thus, non-stepper motors can be employed, which allows for design flexibility. At the same time, the design becomes volumetrically efficient and the angular position sensor is physically protected.

[0026] According to a further embodiment of this aspect of the invention, the rotating member is a brake disc, and the at least one friction member comprises two friction members arranged on a respective one of the two pressing members, the two pressing members being configured to clamp the friction members on the brake disc in response to a braking command to perform a braking action. Such a brake disc arrangement typically allows very efficient braking of a rail vehicle.

[0027] According to another aspect of the present invention, the object is achieved by a computer-implemented method implemented in at least one processing circuit system, the method for controlling an electric brake assembly for a rail vehicle, and the brake assembly includes: a rotating member, the rotating member mechanically connected to the wheel axle of the rail vehicle; at least one friction member, the at least one friction member can be moved between an engaged position and at least one disengaged position, in which the at least one friction member contacts the rotating member, and in which the at least one disengaged position, the rotating member can rotate freely without contacting the at least one friction member; a gear assembly, the gear assembly is arranged to mechanically operate the at least one friction member; and a motor, the motor can be controlled via a control signal and is configured to cause the gear assembly to operate the at least one friction member to move between the engaged position and the at least one disengaged position. The method involves generating a control signal. In addition, when generating the control signal, the method involves obtaining a pulse count signal and a pressure signal. Each pulse in the pulse count signal reflects a specific angular movement of the output shaft of the motor, and the pressure signal indicates the magnitude of the force experienced in the gear assembly when the at least one friction member is in at least one of the at least one disengaged position and the engaged position. Based on the pulse count and the pressure signal, it is checked whether the wear of the at least one friction member meets an alarm criterion, and if the alarm criterion is met, the method involves triggering an alarm. The advantages of the method and its preferred embodiments will become apparent from the above discussion with reference to the proposed electric brake assembly.

[0028] According to a further aspect of the invention, the object is achieved by a computer program loadable into a non-volatile data carrier communicatively connected to a processing unit. The computer program comprises software for performing the above method when the program is run on the processing unit.

[0029] According to another aspect of the invention, the object is achieved by a non-volatile data carrier comprising the above-mentioned computer program.

[0030] Further advantages, advantageous features and applications of the invention will become apparent from the following description and the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The invention will now be explained in more detail by means of preferred embodiments disclosed as examples and with reference to the accompanying drawings.

[0032] Figure 1 Schematically illustrating a rail vehicle including an electric brake assembly according to one embodiment of the present invention;

[0033] Figure 2 An electric brake assembly according to one embodiment of the present invention is shown;

[0034] Figure 3a to Figure 3c illustrates an engaged position and different disengaged positions of the at least one friction member according to an embodiment of the present invention;

[0035] Figure 4 A block diagram of a measurement controller according to an embodiment of the present invention is shown;

[0036] Figure 5a to Figure 5c A graph showing how to monitor the wear of a friction member according to a first embodiment of the present invention;

[0037] Figures 6a to 6c a graph showing how to monitor the wear of a friction member according to a second embodiment of the present invention; and

[0038] Figure 7 The general method according to the invention is illustrated with the aid of a flow chart. DETAILED DESCRIPTION

[0039] exist Figure 1 , a schematic representation of a rail vehicle 100 including an electric brake assembly 200 according to one embodiment of the present invention can be seen. The brake assembly 200 includes: a rotating member 110, at least one friction member 221 and 222, a gear assembly 220, a motor 230, and a controller 120, the controller being configured to obtain a pulse count signal PC and a pressure signal F. Each pulse count in the pulse count signal PC reflects a specific angular movement of the output shaft of the motor 230. The pressure signal F indicates the magnitude of the force experienced in the gear assembly 220 when the at least one friction member 221 and 222 is located in at least one predetermined position. As will be discussed below, the pressure signal F can be generated by the force sensor 225, or obtained in an alternative manner. Similarly, the pulse count signal PC can be generated by the angular position sensor 237, or obtained in an alternative manner.

[0040] The rotating member 110 is mechanically coupled to an axle 115 of the rail vehicle 100. Typically, the axle 115 in turn carries two wheels configured to roll on a respective track. Figure 1 One such wheel 105 is illustrated.

[0041] Now also refer to Figure 3a and Figure 3b, at least one friction member is illustrated here by 221 and 222, respectively. However, it should be noted that the arrangement of the at least one friction member and the rotating member can be realized in an alternative manner. For example, the rotating member can be a rotating cylindrical piece, on which one or more friction members act from the inside (such as in a conventional drum brake) and / or from the outside. Thus, the rotating member 110 can be a brake disc, and the friction members 221 / 222 can include two friction members, which are arranged on a respective one of the two pressing members 211 and 212, which are configured to respond to the braking command cmd B The friction members 221 and 222 are clamped on the brake disc 110 respectively to perform a braking action, for example, the braking command is received in the controller 120 via the control bus 150 in the rail vehicle 100 .

[0042] In any case, the friction member can be in the engaged position P ENG With at least one disengagement position P DIS1 / P DIS2 In the engaged position, the friction members 221 and 222 contact the rotating member 110, and in the at least one disengaged position, the rotating member 110 can rotate freely without contacting any of the friction members 221 or 222. In one embodiment of the present invention, the rotating member 110 is a brake disc, and the at least one friction member includes two friction members, such as Figure 1 , Figure 3a and Figure 3b In the figure, the friction members are shown by 221 and 222 respectively, and are arranged on a corresponding one of the two pressing members 211 and 212, which are configured to respond to the braking command cmd B Instead, the friction members 221 and 222 are respectively clamped on the brake disc 110 and thus a braking action is performed.

[0043] The gear assembly 220 is arranged to mechanically operate the friction members 221 and 222, and can control the motor 230 via the control signal CS so that the gear assembly 220 operates the friction members 221 and 222 to respectively engage in the engagement position P ENG With the release position P DIS1 / P DIS2 Move between.

[0044] Now also refer to Figure 2According to one embodiment of the present invention, a force sensor 225 is arranged in the gear assembly 220. The force sensor 225 may, for example, include a load cell or a wire strain gauge, and is configured to generate a pressure signal F indicating the magnitude of the force when the friction members 221 and 222 contact the rotating member 110 or are pushed away from the rotating member to reach the outer end position. It is advantageous to include the force sensor 225 in the gear assembly 220 because it is mechanically protected from external influences. Specifically, the force sensor 225 may be included in one or both of the first bolt B1 and the second bolt B2 of the gear assembly 220, via which the output force from the motor 230 is transmitted to the friction members 221 and 222. Therefore, whenever these elements come into contact with each other, the force sensor 225 will record a pressure signal, which can be directly converted into the pressure of the contact surface between the friction members 221 / 222 and the rotating member 110.

[0045] According to another embodiment of the present invention, the motor 230 is designed to generate a rotational force on the output shaft of the motor 230, which is proportional to the drive current fed to the motor 230. The controller 120 is also configured to derive the pressure signal F based on the drive current fed into the motor 230. Therefore, the force sensor 225 is not required. Instead, its function is implemented inside the controller 120, for example by running software, by which the pressure signal F is calculated using the drive current and time as input parameters.

[0046] According to one embodiment of the present invention, the motor 230 is a stepper motor configured to generate a pulse count signal PC. Therefore, a dedicated pulse generator is not required.

[0047] According to one embodiment of the present invention, the brake assembly 200 includes an angular position sensor 237, which may be included in the bevel gear 235 of the brake assembly 200. The bevel gear 235 is arranged to connect the output shaft of the motor 230 with the gear assembly 220 so as to transmit mechanical power from the motor 230 to the gear assembly 220 and further to the friction members 221 / 222. The angular position sensor 237, which may be implemented by means of a tachometer, is configured to generate a pulse count signal PC. It is beneficial to include the angular position sensor 237 in the bevel gear 235 because this makes the overall design physically compact and at the same time, the angular position sensor 237 is protected from dust and mechanical damage.

[0048] Figure 4A block diagram of a controller 120 according to one embodiment of the present invention is shown. The controller 120 comprises a processing circuit in the form of at least one processor 430 and a storage unit 420 (i.e., a non-volatile data carrier) storing a computer program 425, which in turn contains software for causing the at least one processor 430 to perform the actions mentioned in the present disclosure when the computer program 425 is run on the at least one processor 430.

[0049] The force signal F is a potential input signal for the controller 120. However, as described above, this signal may alternatively be obtained internally to the at least one processor 430 based on the drive current fed into the motor 230. Nevertheless, the pulse count signal PC is an input signal for the controller 120. The controller 120 is configured to generate a control signal CS and trigger an alarm A if an alarm criterion regarding wear of at least one friction member 221 / 222 is met. The controller 120 is configured to trigger the alarm A according to the following.

[0050] During the process of generating the control signal CS, the controller 120 is configured to obtain the pulse count and pressure signals PC and F, respectively.

[0051] Specifically, the pressure signal F indicates that when the friction member 221 / 222 is in the engagement position P ENG and / or out of position P DIS2 , indicating the magnitude of the force experienced in the gear assembly 220 when φ is 0, thereby indicating the maximum retraction of the friction member 221 / 222 from the rotating member 110, ie, one or both of the two extreme positions of the friction member 221 / 222 relative to the rotatable member 110. Figure 3c Shows the disengaged position P DIS2 Based on the pressure and pulse count signals F and PC, the controller 120 is configured to check whether an alarm criterion is met; and the controller 120 is further configured to trigger the alarm A if the alarm criterion is met. In practice, the triggering of the alarm A may, for example, involve setting a flag in a maintenance database, sending a message to one or more designated recipients, and / or generating an audible and / or visual alarm.

[0052] Now, refer to Figure 3a , Figure 3b , Figure 5a , Figure 5b and Figure 5c , we will explain how to monitor the wear of the friction member 221 / 222 according to the first embodiment of the present invention. Here, the controller 120 is configured to perform the following steps: (a1), (b1), (c1), and (d1).

[0053] In step (a1), the controller 120 records a first number of pulse counts PC[n] obtained via the pulse count signal PC, and the controller 120 generates a control signal CS to control the motor 230 to cause the gear assembly 220 to operate the friction member 221 / 222 in the approach direction, i.e., wherein the friction member 221 / 222 is moved from the first disengaged position P DIS1 Move to the engagement position P ENG Preferably, but not necessarily, the first disengaged position P DIS1 The friction member 221 / 222 is arranged at an idle distance d from the rotating member 110 IDL Idle distance d IDL Then, the predefined static position of the friction member 221 / 222 between the braking operations, ie, the initial position, is defined. When the controller 120 receives the braking command cmd B From this initial position, a stationary position braking operation can then be achieved with predictable delay. In other words, when the friction members 221 and 222 are at the idle distance d IDL When the motor 230 is in the forward direction, the friction members 221, 222 can be moved to the engagement position P by controlling the motor 230 in the forward direction until a first predefined number of pulse counts has been obtained in the controller 120 via the pulse count signal PC. ENG We assume that the friction member 221 / 222 reaches the rotating member 110 at time point t1.

[0054] After t1 , the controller 120 continues to generate the control signal CS to control the motor 230 to cause the gear assembly 220 to operate the friction members 221 / 222 in the approaching direction until the pressure signal F exceeds the positive threshold F1 . Figure 5c This event is shown at a time point t2 after t1. When the pressure signal F has exceeded the positive threshold F1, the controller 120 stops controlling the motor 230 to cause the gear assembly 220 to operate the friction members 221 / 222 in the approach direction.

[0055] In a subsequent step (b1), the controller 120 compares the pulse count of the first number PC[n] with the pulse count base recorded by the controller 120 in a previously executed step (a1) (usually the most recently executed step (a1)). If the base is lower than the first number, then step (c1) follows. Otherwise, the program loops back to step (a1) to wait for the brake command cmd B In response to the command, the brake assembly 200 is configured to perform a braking action.

[0056] In step (c1), the controller increases the wear count by the difference between the first number PC[n] and the base number. Under normal circumstances, the wear count is increased by at most one count at a time. However, of course, larger increments are not excluded, for example if the brake assembly 200 performs an extremely violent braking operation. In any case, the controller 120 compares the wear count with the threshold count, and if the wear count exceeds the threshold count, step (d1) follows. Otherwise, the program loops back to step (a1).

[0057] In step (d1 ), the controller 120 triggers an alarm A, which may involve, for example, setting a flag in a maintenance database, sending a message to at least one designated recipient, and / or generating an audible and / or visual alarm.

[0058] Reference now Figure 3a , Figure 3c , Figure 6a , Figure 6b and Figure 6c , we will explain how to monitor the wear of the friction members 221 / 222 according to the second embodiment of the present invention.

[0059] Here, the controller 120 is configured to perform the following steps: (a2), (b2), and (c2).

[0060] In step (a2), the controller 120 generates a control signal CS to control the motor 230 to operate the gear assembly 220 so that the gear assembly 220 moves the friction member 221 / 222 from the engagement position P to the engagement position P in a retracting direction away from the rotating member 110. ENG Retract outward. Assume that initially, the friction member 221 / 222 is applied to the rotating member 110 so that the pressure signal F is the positive threshold F1; thereafter, at time point t3, the friction member 221 / 222 releases the rotating member 110; and at a later time point t4, the friction member 221 / 222 reaches a position where the friction member 221 / 222 is maximally retracted from the rotating member 110, i.e., a position where the friction member 221 / 222 is located at the outermost position relative to the rotating member 110. This represents the second disengaged position P of the friction member 221 / 222 DIS2 In order to verify whether the second disengagement position P has been reached DIS2, the controller 120 continues to generate the control signal CS to control the motor 230 to operate the gear assembly 220, so that the gear assembly 220 moves in the retracting direction, until the pressure signal F drops below the negative threshold value -F2 at a time point t5 after t4. The negative threshold value -F2 here confirms that the friction member 221 / 222 has reached the outermost position relative to the rotating member 110; and in response thereto, the controller 120 stops generating the control signal CS to control the motor 230 to operate the gear assembly 220, so that the gear assembly 220 retracts the friction member 221 / 222 outward from the rotating member 110.

[0061] Step (b2) involves recording a second number PC[m] of pulse counts obtained via the pulse count signal PC when performing step (a2). If the second number PC[m] exceeds the threshold count, this means that the friction member 221 / 222 has traveled too far from the rotating member 110 to the second disengaged position P DIS2 , which is a sign that the friction member 221 / 222 is worn.

[0062] Therefore, in step (c2) after step (b2), the controller 120 triggers the alarm A. However, if the second number PC[m] does not exceed the threshold count, the program loops back to step (a2) to wait for the braking command cmd B Updates.

[0063] It is worth noting that due to Figure 2 , Figure 3a , Figure 3b and Figure 3c In the illustrated embodiment, the two pressing members 211 and 212 clamp the friction members 221 and 222 on the brake disc 110 from opposite sides, respectively. Figure 5b and Figure 6b The first pulse count PC[n] and the second pulse count PC[m] in respectively reflect the sum of a first distance from the first side of the rotating member 110 to the first friction member 211 and a second distance from the second side of the rotating member 110 to the second friction member 212. However, if a drum brake is employed in which a single friction member is clamped on the outside or on the outside of a drum, the first pulse count PC[n] and the second pulse count PC[m] reflect only one distance between the friction member and the drum.

[0064] To summarize and with reference to the flowchart in FIG. 6 , a computer-implemented method for controlling an electric brake assembly for a rail vehicle according to the present invention, implemented in at least one processing circuit, such as the at least one processor 430 described above, will now be described.

[0065] Assume that the brake assembly comprises: a rotating member 110 mechanically connected to the wheel axle 115 of the rail vehicle 100; ENG With one or more disengagement positions P DIS1 and / or P DIS2 at least one friction member 221 / 222 moving between the engagement position, in which the at least one friction member 221 / 222 contacts the rotating member 110, and in which the one or more disengaged positions, the rotating member 110 can rotate freely without contacting the at least one friction member 221 / 222; a gear assembly 220, which is arranged to mechanically operate the at least one friction member 221 / 222; and a motor 230, which can be controlled via a control signal CS and is configured to cause the gear assembly 220 to operate the at least one friction member 221 / 222 to engage the engagement position P ENG With the release position P DIS1 / P DIS2 Move between.

[0066] In a first step 710, a control signal CS is generated, and in steps 720 and 730 in parallel with step 710, a pulse count signal PC and a pressure signal F are obtained, respectively. Each pulse count in the pulse count signal PC reflects a specific angular movement of the output shaft of the motor 230, and the pressure signal F indicates when at least one friction member 221 / 222 is in the engaged position P. ENG and / or one of the disengaged positions (preferably P DIS2 ) is the magnitude of the force experienced in the gear assembly 220.

[0067] Step 740 is followed by steps 710, 720 and 730 to check whether the wear of at least one friction member 221 / 222 meets the alarm criteria. For example, this can be checked by executing the above steps (a1) to (d1) or (a2) to (c2). If the alarm criteria are met, step 750 follows. Otherwise, the program loops back to steps 710, 720 and 730.

[0068] In step 750, alarm A is triggered and the process ends.

[0069] refer to Figure 7All process steps described and any subsequence of steps can be controlled by means of a programmed processor. In addition, although the embodiments of the present invention described above with reference to the accompanying drawings include a processor and a process executed in at least one processor, the present invention is therefore also extended to a computer program adapted to put the present invention into practice, in particular a computer program on or in a carrier. The program can be in the form of source code, object code, intermediate source code and object code (such as in a partially compiled form), or any other form suitable for implementing the process according to the present invention. The program can be part of an operating system, or it can be a separate application. The carrier can be any entity or device capable of carrying the program. For example, the carrier can include a storage medium such as a flash memory, a ROM (read-only memory), such as a DVD (digital video / versatile disk), a CD (optical disk) or a semiconductor ROM, an EPROM (erasable programmable read-only memory), an EEPROM (electrically erasable programmable read-only memory) or a magnetic recording medium, such as a floppy disk or a hard disk. In addition, the carrier can be a transmittable carrier, such as an electrical signal or optical signal that can be transmitted via a cable or optical cable or by radio or by other means. When the program is embodied in a signal that can be directly transmitted by a cable or other device or means, the carrier can be composed of such a cable or device or means. Alternatively, the carrier may be an integrated circuit in which the program is present, the integrated circuit being adapted to perform or intended to perform the relevant process.

[0070] When used in this specification, the terms "comprises / comprising" are used to specify the presence of stated features, integers, steps or components. The terms do not exclude the presence or addition of one or more additional elements, features, integers, steps or components or groups thereof. The indefinite article "a" or "an" does not exclude a plurality. In the claims, the word "or" should not be interpreted as an exclusive or (sometimes referred to as "XOR"). On the contrary, unless otherwise indicated, expressions such as "A or B" cover all cases of "A and not B", "B and not A" and "A and B". The mere fact that certain measures are cited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be interpreted as limiting the scope.

[0071] It should also be noted that features from the various embodiments described herein may be combined freely, unless it is explicitly stated that such a combination is inappropriate.

[0072] Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.

[0073] The invention is not limited to the embodiments described in the figures but may be varied freely within the scope of the claims.

Claims

1. An electric brake assembly (200) for a rail vehicle (100), the brake assembly (200) comprising: a rotating member (110) mechanically coupled to a wheel axle (115) of the rail vehicle (100), At least one friction member (221; 222) capable of being in an engaged position (P ENG ) and at least one disengagement position (P DIS1 , P DIS2 ), in the engaged position, the at least one friction member (221; 222) contacts the rotating member (110), and in the at least one disengaged position, the rotating member (110) is able to rotate freely without contacting the at least one friction member (221; 222), a gear assembly (220) arranged to mechanically operate the at least one friction member (221; 222), An electric motor (230) is controllable via a control signal (CS) and is configured to cause the gear assembly (220) to operate the at least one friction member (221; 222) in the engagement position (P ENG ) and at least one disengagement position (P DIS1 , P DIS2 ), and A controller (120) configured to generate the control signal (CS), characterized in that during the process of generating the control signal (CS), the controller (120) is configured to: obtaining a pulse count signal (PC), wherein each pulse count reflects a specific angular movement of an output shaft of the motor (230), A pressure signal (F) is obtained, wherein the pressure signal indicates that when the at least one friction member (221; 222) is located in the at least one disengaged position (P DIS2 ) and the engagement position (P ENG ) is the magnitude of the force experienced in the gear assembly (220), Based on the pressure signal (F) and the pulse count signal (PC), it is checked whether the wear of the at least one friction member (221; 222) meets an alarm criterion, and if the alarm criterion is met, Trigger the alarm (A).

2. The brake assembly (200) according to claim 1, wherein the controller (120) is configured to perform the following steps: (a1) recording a first number of pulse counts (PC[n]) obtained via the pulse count signal (PC), and generating the control signal (CS) to control the motor (230) to move the gear assembly (220) along the at least one friction member (221; 222) from a first disengaged position (P DIS1 ) moves to the engagement position (P ENG ), operating the at least one friction member (221; 222) in the approaching direction of the pressure signal (F), continuing to generate the control signal (CS) to control the motor (230) to cause the gear assembly (220) to operate the at least one friction member (221; 222) along the approaching direction until the pressure signal (F) exceeds the positive threshold value (F1), (b1) comparing the pulse count of the first number (PC[n]) with the cardinality of the pulse count recorded in the previous execution of step (a1), and if the cardinality is lower than the first number, then (c1) increasing the wear count by the difference between the first number (PC[n]) and the base number, and if the wear count exceeds a threshold count, then (d1) triggers the alarm (A).

3. The brake assembly (200) according to claim 2, wherein the first disengaged position (P DIS1 ) represents the idle distance (d) between the rotating member (110) and the at least one friction member (221; 222) IDL ), the idle distance (d IDL ) defines a predefined static position of the at least one friction member (221; 222) between braking operations.

4. The brake assembly (200) according to any one of the preceding claims, wherein the controller (120) is configured to perform the following steps: (a2) generating the control signal (CS) to control the motor (230) to operate the gear assembly (220) so that the gear assembly (220) moves the at least one friction member (221; 222) from the rotating member (110) in a retracting direction from the engagement position (P ENG ) retracts outwardly until the pressure signal (F) drops below a negative threshold (-F2) that specifies a maximum retraction of the at least one friction member (221; 222) from the rotating member (110), the maximum retraction representing a second disengaged position (P DIS2 ), (b2) recording a second number (PC[m]) of pulse counts obtained via the pulse count signal (PC) when performing step (a2), and if the second number (PC[m]) exceeds a threshold count, then (c2) Triggering the alarm (A).

5. The brake assembly (200) according to any one of the preceding claims, wherein: The motor (230) is configured to generate a rotational force on an output shaft of the motor (230), the rotational force being proportional to a drive current fed into the motor (230), and The controller (120) is configured to derive the pressure signal (F) based on the drive current fed into the motor (230).

6. The brake assembly (200) according to any one of claims 1 to 4, wherein the gear assembly (220) comprises a force sensor (225) configured to generate the pressure signal (F).

7. The brake assembly (200) of claim 6, wherein the force sensor (225) comprises one of a load cell and a wire strain gauge.

8. The brake assembly (200) according to claims 6 to 7, wherein the force sensor (225) is arranged on a bolt (B1, B2) in the gear assembly (220).

9. The brake assembly (200) according to any one of the preceding claims, wherein the electric motor (230) is a stepper motor configured to generate the pulse count signal (PC).

10. The brake assembly (200) according to any one of claims 1 to 8, wherein the angular position sensor (237) is a separate component from the electric motor (230).

11. The brake assembly (200) of claim 10, wherein the angular position sensor (237) is included in a bevel gear (235) arranged to connect the output shaft of the motor (230) with the gear assembly (220).

12. The brake assembly (200) according to any one of the preceding claims, wherein the rotating member (110) is a brake disc, and the at least one friction member (221; 222) comprises two friction members arranged on a respective one of two pressing members (211; 212), the two pressing members being configured to respond to a braking command (cmd B ) clamps the friction member (221; 222) onto the brake disc (110) to perform a braking action.

13. A computer-implemented method for controlling an electric brake assembly (200) for a rail vehicle (100), the brake assembly (200) comprising: a rotating member (110) mechanically coupled to an axle (115) of the rail vehicle (100); At least one friction member (221; 222) capable of being in an engaged position (P ENG ) and at least one disengagement position (P DIS1 , P DIS2 ), in the engaged position, the at least one friction member (221; 222) contacts the rotating member (110), and in the at least one disengaged position, the rotating member (110) is able to rotate freely without contacting the at least one friction member (221; 222); a gear assembly (220), the gear assembly being arranged to mechanically operate the at least one friction member (221; 222); and a motor (230), the motor being controllable via a control signal (CS) and configured to cause the gear assembly (220) to operate the at least one friction member (221; 222) to engage the at least one friction member (221; 222) in the engaged position ((P ENG ) and at least one disengagement position (P DIS1 , P DIS2 ), the method comprising: generating the control signal (CS), It is characterized in that, when generating the control signal (CS), the method further comprises: obtaining a pulse count signal (PC), wherein each pulse count reflects a specific angular movement of an output shaft of the motor (230), A pressure signal (F) is obtained, wherein the pressure signal indicates that when the at least one friction member (221; 222) is located in the at least one disengaged position (P DIS2 ) and the engagement position (P ENG ) is the magnitude of the force experienced in the gear assembly (220), based on which, checking whether the wear of the at least one friction member (221; 222) satisfies an alarm criterion, and if the alarm criterion is satisfied, Trigger the alarm (A).

14. The method according to claim 13, further comprising the steps of: (a1) recording a first number of pulse counts (PC[n]) obtained via the pulse count signal (PC), and generating the control signal (CS) to control the motor (230) to move the gear assembly (220) along the at least one friction member (221; 222) from a first disengaged position (P DIS1 ) moves to the engagement position (P ENG ), operating the at least one friction member (221; 222) in the approaching direction of the pressure signal (F), continuing to generate the control signal (CS) to control the motor (230) to cause the gear assembly (220) to operate the at least one friction member (221; 222) along the approaching direction until the pressure signal (F) exceeds the positive threshold value (F1), (b1) comparing the pulse count of the first number (PC[n]) with the base of the pulse count recorded in the previous execution of step (a1), and if the base is lower than the first number, then (c1) increasing the wear count by the difference between the first number (PC[n]) and the base number, and if the wear count exceeds a threshold count, then (d1) triggers the alarm (A).

15. The method according to claim 14, wherein the first disengagement position (P DIS1 ) represents the idle distance (d) between the rotating member (110) and the at least one friction member (221; 222) IDL ), the idle distance (d IDL ) defines a predefined rest position of the at least one friction member (221; 222) between braking operations.

16. The method according to any one of claims 13 to 15, further comprising the steps of: (a2) generating the control signal (CS) to control the motor (230) to operate the gear assembly (220) so that the gear assembly (220) moves the at least one friction member (221; 222) from the rotating member (110) in a retracting direction from the engagement position (P ENG ) retracts outwardly until the pressure signal (F) drops below a negative threshold (-F2) that specifies a maximum retraction of the at least one friction member (221; 222) from the rotating member (110), the maximum retraction representing a second disengaged position (P DIS2 ), (b2) recording a second number (PC[m]) of pulse counts obtained via the pulse count signal (PC) when performing step (a2), and if the second number (PC[m]) exceeds a threshold count, then (c2) Triggering the alarm (A).

17. A computer program (425) loadable into a non-volatile data carrier (420), the non-volatile data carrier being communicatively connected to at least one processor (430), the computer program (425) comprising software for performing a method according to any one of claims 12 to 15 when the computer program (425) is run on the at least one processor (430).

18. A non-volatile data carrier (420) comprising a computer program (425) as claimed in claim 16.

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