Controller for controlling a rail vehicle brake unit, computer-implemented method therefor, computer program and non-

Abstract

A controller (140) receives a braking command (B) and, in response to the braking command, controls an electrically operated braking unit to apply a respective braking force to a respective rotating member (111, 112, 113, 114) mechanically coupled to a wheel (121a, 121b, 122a, 122b, 123a, 123b, 124a, 124b) of a rail vehicle (100), thereby reducing the speed of the rail vehicle. The controller (140) repeatedly checks whether each brake unit satisfies operability criteria and has no failure (OK), or does not satisfy operability criteria and has failure (F). The controller (140) also repeatedly determines an adhesion parameter reflecting a coefficient of friction between the at least one wheel (121a, 121b) and the at least one rail (191, 192) on which the rail vehicle (100) travels; based on the adhesion parameter, it is estimated whether a respective braking force of each failure-free (OK) braking unit (172, 173, 174) is likely to be increased to compensate for any failed (F) braking unit (171), and if so, the failure-free (OK) braking unit is controlled to apply a respective braking force to a respective rotating member in response to a braking command (B), the respective braking force is increased to compensate for any failed braking unit.

Description

TECHNICAL FIELD

[0001] The present invention relates generally to the deceleration of a rail vehicle. In particular, the present invention relates to a controller for controlling brake units of a rail vehicle according to the preamble of claim 1. The invention further relates to a corresponding computer-implemented method, a computer program and a non-transitory data carrier storing such a computer program. BACKGROUND

[0002] For obvious reasons, a failure of a rail vehicle brake system can lead to catastrophic consequences. In practice, however, a smaller number of faulty brake units does not necessarily have to be very serious. This is because the brake capacity of a rail vehicle is usually designed to be oversized, which is precisely to cope with such failure situations.

[0003] Today, when a brake unit fails, the on-board safety and monitoring system informs the train driver about the problem and the resulting reduction of brake capacity. Based on the fact that the brake capacity has been reduced, the train engineer needs to calculate the updated brake capacity, the updated maximum speed of the rail vehicle and manually adjust the value of the overall brake force available, both for the on-board monitoring system and for the traffic control system. This is a time-consuming process and is susceptible to human factor related errors. Due to various safety considerations and margins, some of which are dictated by infrastructure related factors, the process also usually results in a more stringent brake performance than actually required. Thus, the existing strategy for handling brake failures provides results that are too coarse and results in a loss of capacity in terms of railway network trafficability.

[0004] US 6,520,599 describes a pneumatic system as a backup to an electronic system that normally provides load compensation for a rail vehicle bogie during service and emergency brake applications. Whenever the electronic load compensation system fails due to a power outage or other electrical failure, the pneumatic system compensates for the loads experienced by the rail vehicle during service and emergency brake applications. The system is applicable to rail vehicle bogies equipped with brake pipe controlled brake equipment. The pneumatic system provides load compensation by using a four-way variable load valve in combination with a low complexity MC-30A-1 control valve.

[0005] US 6,062,657 discloses a system and method for providing braking for a vehicle having at least two sets of braking devices intended to provide braking force for a deceleration rate in response to a braking force request, wherein each set of braking devices has a residual braking force. In the event of a failure or unavailability of one set of braking devices, the residual available braking force in the other set of braking devices can be utilized to make up for the deficiency, thereby providing the requested deceleration rate to the vehicle.

[0006] US 7,597,408 discloses a method for compensating for regenerative braking amount when the vehicle regenerative braking fails due to a controller area network (CAN) communication error between an electronic brake system (EBS) and a hybrid control unit (HCU). The method includes the steps of determining whether regenerative braking is activated, memorizing a regenerative braking control amount in the HCU and the EBS, learning and memorizing a difference between the regenerative braking control amount just calculated in the HCU and the EBS in a normal state and a braking amount for fault checking, compensating for the braking amount for fault checking using the difference between the normal regenerative braking control amount and the braking amount for fault checking, and performing regenerative braking control in the HCU and the EBS, respectively.

[0007] EP 3 554 904 presents an intelligent locomotive brake control system that selects and optimizes the use of dynamic braking, independent braking, and automatic braking on a locomotive to ensure expected braking power, minimize internal forces on the train, minimize brake component wear, and automate standard train brake protocols. The system can be programmed to modify automatic brake applications instructed by a train driver to omit or reduce the amount of automatic brake application in favor of dynamic brake application, independent brake application, or a combination of both.

[0008] Therefore, different strategies are known for handling various types of braking faults in a rail vehicle. However, there is currently no satisfactory solution that, on the one hand, is able to automatically compensate for the unavailability of a subset of braking devices and, on the other hand, is able to exploit the potential of the available braking devices to the full under the current conditions. SUMMARY

[0009] The object of the present invention is to solve the above-mentioned problems and to provide a solution that enables the rail vehicle service braking devices to be used in an optimal manner.

[0010] According to an aspect of the application, the object is achieved by a controller for controlling a set of electrically operated brake units of a rail vehicle. The controller is configured to receive a braking command, e.g. over a data bus, and in response to the braking command, control the brake units to apply respective braking forces to respective rotating members mechanically connected to wheels of the rail vehicle, thereby reducing the speed of the rail vehicle. The controller is further configured to repeatedly check, for each brake unit, whether the brake unit fulfils an operability criterion and is considered fault-free, or does not fulfil the operability criterion and is considered faulty. Furthermore, the controller is configured to repeatedly determine a sticking parameter reflecting a coefficient of friction between at least one of the wheels and at least one rail on which the rail vehicle is travelling. In turn, based on the sticking parameter, the controller is configured to estimate whether it is possible to increase the respective braking force of each fault-free brake unit to compensate for any faulty brake units in the set of brake units. If such an increase is estimated to be possible, the controller is configured to control the fault-free brake units to apply respective braking forces to the respective rotating members, the respective braking forces being increased to compensate for any faulty brake units, in response to the braking command.

[0011] The above controller has the advantage that it allows the braking arrangement of the rail vehicle to operate as efficiently as possible given its capacity and the current sticking conditions. Thus, even if a smaller number of brake units fail, the rail vehicle can continue to operate without any corrective measures having to be taken. Of course, it is preferred that the faulty brake units should be repaired at the earliest opportunity to restore full operability of the rail vehicle.

[0012] According to an embodiment of this aspect of the application, in response to the braking command, the controller is configured to control the fault-free brake units to apply respective increased braking forces to compensate for any faulty brake units until either of the following events first occurs: (i) a subsequent check reveals that at least one additional brake unit of the brake units is considered faulty, or (ii) it is estimated that for a subsequently determined sticking parameter, it is not possible to increase the respective braking force of each fault-free brake unit to compensate for any faulty brake units. That is, in the former case, it must be checked whether the fault-free brake units are considered capable of compensating for the faulty brake units; whereas in the latter case, the braking capacity must be re-evaluated.

[0013] According to a further embodiment of this aspect of the application, if a subsequent check reveals that at least one additional brake unit of the brake units is considered faulty, the controller is configured to estimate, on the basis of the adhesion parameter, whether it is possible to further increase the respective brake force of each non-faulty brake unit, thereby also compensating for the at least one additional faulty brake unit. If it is estimated that such a further increase is possible, the controller is configured to control the non-faulty brake units to apply, in response to the brake command, the respective brake force to the respective rotating member, which is increased thereby also compensating for the additional faulty brake unit. Thus, the braking capacity of the rail vehicle can be automatically adjusted in order to also accommodate further brake unit failures in an expedient manner.

[0014] According to yet another embodiment of this aspect of the application, if it is estimated that it is not possible to increase the respective brake force of each non-faulty brake unit to compensate for any faulty brake unit for the subsequently determined adhesion parameter, the controller is configured to recalculate the braking capacity of the rail vehicle. Here, the recalculated braking capacity is based on the non-faulty brake units and the adhesion parameter. Thus, if the non-faulty brake units are unable to compensate for the faulty brake units, the braking capacity will be automatically updated to the braking capacity that is possible to achieve under the current adhesion conditions. Preferably, in connection therewith, the controller is also configured to issue an alarm signal, e.g. informing the train driver of the updated braking capacity.

[0015] According to a further embodiment of this aspect of the application, the controller is configured to estimate, on the basis of the total weight of the rail vehicle, whether it is possible to increase the respective brake force of each non-faulty brake unit to compensate for any faulty brake unit. Preferably, here the total weight represents the total dynamic weight of the instantaneous kinetic energy of the rail vehicle in question.

[0016] In order to achieve optimal performance, it is preferable to estimate the total weight as accurately as possible. To this end, according to one embodiment of this aspect of the application, the controller is configured to estimate the total weight of the rail vehicle on the basis of a power signal and a speed signal, the power signal being indicative of the amount of power produced by a set of drive units in the rail vehicle when accelerating the rail vehicle from a first speed to a second speed, the speed signal being indicative of respective values of the first speed and the second speed. That is, the power signal and the speed signal form the basis for calculating an accurate measure of the current total weight of the rail vehicle.

[0017] According to a further embodiment of this aspect of the application, the controller is configured to determine the adhesion parameter as follows: (a) obtain wheel speed signals indicative of respective rotational speeds of axles in the driving subset of axles of the rail vehicle; (b) control a particular drive unit of the set of drive units to generate an acceleration control signal such that the drive unit applies an increasing traction force to a particular axle of the axles in the driving subset of axles; (c) during generation of the acceleration control signal, repeatedly determine an absolute difference between the rotational speed of the particular axle and an average rotational speed of the axles in the driving subset of axles excluding the particular axle; and in response to the absolute difference exceeding a threshold value, (d) determine the adhesion parameter. This iterative and increasing stress on the wheel-rail interface enables a precise and thorough examination of the specific conditions that determine the adhesion parameter.

[0018] According to a further embodiment of this aspect of the application, it is assumed that the rail vehicle has m brake units in common. Furthermore, if the brake command indicates that a total braking force of xm is to be applied to all rotating members, and if n brake units are faulty, the controller is configured to control each of the m-n non-faulty brake units to apply a respective braking force of x(n+1) / n to each rotating member. In other words, the braking load is evenly distributed over the non-faulty brake units. As a basic rule, this is a reasonable approach. However, in order to obtain optimal efficiency, it can often be advantageous to assign a slightly higher braking load to brake units located at the front of the rail vehicle than to brake units located at the rear.

[0019] According to a further aspect of the application, the object is achieved by a computer-implemented method for controlling a set of electrically operated brake units in a rail vehicle, the method being executed in a processing unit of a controller of the rail vehicle. The method involves receiving a brake command and, in response to the brake command, controlling the brake units to apply respective braking forces to respective rotating members mechanically connected to wheels of the rail vehicle, thereby reducing the speed of the rail vehicle. The method further involves repeatedly checking, for each brake unit, whether the brake unit meets an operability criterion and is considered non-faulty or does not meet the operability criterion and is considered faulty; repeatedly determining an adhesion parameter reflecting a friction coefficient between at least one of the wheels and at least one rail on which the rail vehicle is travelling; based on the adhesion parameter, estimating whether it is possible to increase the respective braking force of each non-faulty brake unit to compensate for any faulty brake units; and if such an increase is estimated to be possible, controlling the non-faulty brake units to apply respective braking forces to the respective rotating members, the respective braking forces being increased to compensate for any faulty brake units, in response to the brake command. The advantages of this method and its preferred embodiments are apparent from the above discussion of the proposed controller.

[0020] According to a further aspect of the present application, the object is achieved by a computer program loadable into a non-volatile data carrier in communication connection with a processing unit. The computer program comprises software for performing the above-mentioned method when the program is run on the processing unit.

[0021] According to a further aspect of the present application, the object is achieved by a computer program loadable into a non-volatile data carrier in communication connection with a processing unit. The computer program comprises software for performing the above-mentioned method when the program is run on the processing unit.

[0022] Further advantages, advantageous features and applications of the present application will appear from the following description and the dependent claims. BRIEF DESCRIPTION OF DRAWINGS

[0023] The present application will now be explained in more detail by means of embodiments disclosed by way of example and with reference to the accompanying drawings.

[0024] Figure 1 A schematic illustration of a rail vehicle equipped with a controller according to an embodiment of the present application is shown;

[0025] Figure 2 A schematic drive unit according to an embodiment of the present application is shown; Figure 3 A graph illustrating an example of a friction coefficient as a function of wheel slip is shown; Figure 4 A block diagram of a controller according to an embodiment of the present application is shown; and Figure 5 The method according to the present application and preferred embodiments thereof are illustrated by means of flow charts. DETAILED DESCRIPTION

[0026] In Figure 1 In Fig. 1, a schematic illustration of a rail vehicle 100 equipped with a controller 140 according to an embodiment of the present application is seen. The rail vehicle 100 can be any type of rail vehicle, such as a locomotive, a freight car, a freight car carriage, a passenger car / coach, a rail motor car / rail bus, and / or any combination thereof.

[0027] The controller 140 is arranged to control a set of electrically operated brake units of the rail vehicle 100, here exemplified as brake units 171, 172, 173 and 174, respectively. To this end, the controller 140 is configured to receive a brake command B, e.g. from a cab or an emergency function of the rail vehicle 100, which e.g. can be activated by a passenger and has a bypass option.

[0028] In response to the braking instruction B, the controller 140 is configured to control each of the brake units 171, 172, 173 and 174 to apply a respective braking force to the corresponding rotational member 111, 112, 113 and 114. The rotational members 111, 112, 113 and 114 in turn are each in mechanical connection with a wheel of the rail vehicle 100. Here, the wheels are exemplified as 121a, 121b, 122a, 122b, 123a, 123b, 124a and 124b, respectively. Either each pair of wheels is mounted on a common axle, such that they rotate together with the axle, or each wheel is mounted on a separate axle, such that it can rotate independently of any other wheel. In either case, the braking force applied to the corresponding rotational member 111, 112, 113 and 114 causes the rail vehicle 100 to reduce its speed.

[0029] For each of the brake units 171, 172, 173 and 174, respectively, the controller 140 is further configured to repeatedly check whether the brake unit fulfils an operability criterion. For example, the operability criterion can stipulate that the brake unit is capable of producing a braking force above a threshold level. If the operability criterion is fulfilled, the brake unit is considered fault-free (OK). However, if the operability criterion is not fulfilled, the brake unit is considered faulty (F).

[0030] According to one embodiment of the present invention, in response to the braking instruction B, the controller 140 is configured to control the fault-free (OK) brake units (e.g. 172, 173 and 174) to apply respective increased braking forces to compensate for the faulty (F) brake unit (e.g. 171), until one or both of the following situations occurs: - a subsequent check reveals that at least one additional brake unit in the set of brake units is considered faulty (F), or - the estimated braking capacity for the determined adhesion parameter m it is not possible to increase the respective braking force of each fault-free (OK) brake unit to compensate for any faulty (F) brake unit.

[0031] That is, in the former case, the controller 140 has to check whether the fault-free (OK) brake units are considered capable of compensating for the faulty (F) brake unit; whereas in the latter case, the braking capacity has to be re-evaluated.

[0032] According to one embodiment of the present invention, if the subsequent check reveals that at least one additional brake unit (e.g. 172) is considered faulty (F), the controller 140 is configured to base the increase of the respective braking force of the fault-free (OK) brake units (e.g. 173 and 174) on the adhesion parameter mIt is estimated whether it is possible to further increase the respective brake force of each non-faulty (OK) brake unit (e.g. 173 and 174) thereby also compensating for at least one additional faulty (F) brake unit 172. If it is estimated that such a further increase is possible, the control unit 140 is configured to control the non-faulty (OK) brake units (173 and 174) to apply a respective brake force to the respective rotating member, which is increased thereby also compensating for the additional faulty (F) brake unit 172, in response to the brake command B.

[0033] According to one embodiment of the present application, if the controller 140 estimates that for the subsequently determined adhesion parameter m it is not possible to increase the respective brake force of each non-faulty (OK) brake unit 173 and 174 to compensate for the faulty (F) brake units 171 and 172, the controller 140 is further configured to recalculate the braking capacity of the rail vehicle 100. Here, the recalculated braking capacity is based on the non-faulty (OK) brake units (173 and 174) and the adhesion parameter m . Preferably, in this case, i.e. if the braking capacity is recalculated, the controller 140 is further configured to issue an alarm signal A, e.g. informing the train driver about the updated braking capacity, for storing in a log file, and / or forwarding to a monitoring function in the rail vehicle and / or a central site. Furthermore, the alarm signal A and / or the updated braking capacity can preferably be transmitted to a control mechanism, e.g. an automatic train protection (ATP) system, e.g. ETCS (European Train Control System).

[0034] Reference is now made to Figure 3 which shows an example graph of how the dynamic friction coefficient k is expressed as a function of the wheel slip s. Here, the wheel slip s is understood or refers to the rotational movement of the wheel relative to the track or to the sliding of the wheel relative to the track. In other words, the wheel slip s applies to both acceleration scenarios as well as to deceleration scenarios.

[0035] Characteristically, for lower values, the dynamic friction coefficient k increases relatively proportionally with increasing wheel slip s. However, when approaching the peak value e , the dynamic friction coefficient k approximately levels off. After passing the peak value, the dynamic friction coefficient k remains essentially constant for all values of the wheel slip s. Thus, the friction coefficient peak value e is associated with an optimal wheel slip se In association with this, beyond the optimal slip, further increase of the wheel slip s leads to a decrease of the dynamic friction coefficient k decreases gradually and then remains almost constant.

[0036] According to one embodiment of the application, the controller 140 is configured to determine a parameter m reflecting a friction coefficient between at least one of the wheels of the rail vehicle 100 and at least one respective rail 191 and / or 192 on which the rail vehicle 100 is travelling.

[0037] Ideally, the peak e of the estimate of the friction coefficient e may be derived as follows. When the rotational speed of a particular driven wheel axle 131 is compared to the average rotational speed of all axles in a driven subset of axles of the rail vehicle 100, excluding the particular driven wheel axle 131, a the absolute difference 1- a When this exceeds a threshold value, this corresponds to the situation that the wheels 121a and 121b on the particular driven wheel axle 131 experience a wheel slip s close to the optimal wheel slip s e m . The dynamic friction coefficient k is given by the expression:

[0038] where F is the driving force applied by the driving unit, m tot is the total weight of the rail vehicle 100, and g is the standard gravitational acceleration.

[0039] Under the assumption that the wheel slip s m is close to the optimal wheel slip s e , the peak k of the dynamic friction coefficient e may be estimated relatively accurately; and by setting the threshold value for the absolute difference a between the rotational speed of the particular driven wheel axle 131 and the average rotational speed of all axles of the rail vehicle 100, excluding the particular driven wheel axle 131, a ensures that the wheel slip s m ​​Approaching optimal wheel slip s e .

[0040] Thus, the adhesion parameter m reflecting the friction coefficient between at least one of the wheels (here 121a and 121b) and at least one of the tracks (191 and 192) on which the rail vehicle 100 is travelling e .

[0041] Furthermore, based on the adhesion parameter m the controller 140 is configured to estimate whether it is possible to increase the respective braking force of each non-faulty (OK) braking unit (e.g. 172, 173 and 174, respectively) to compensate for any faulty (F) braking unit (e.g. 171). Moreover, if such an increase is estimated to be possible, the controller 140 is configured to control the non-faulty (OK) braking units to apply the respective braking force to the respective rotating member, which is increased to compensate for any faulty braking unit, in response to the braking command B.

[0042] According to one embodiment of the present application, the controller 140 is configured to estimate whether it is possible to increase the respective braking force of each non-faulty (OK) braking unit to compensate for a faulty (F) braking unit based on the total weight m tot of the rail vehicle 100. Thus, the controller 140 can be configured to estimate the current total weight m tot of the rail vehicle 100, i.e. the dynamic weight, as described below. This means that the controller 140 takes into account the instantaneous kinetic energy of the rail vehicle 100, i.e. the calculation takes into account the tare weight of the rail vehicle 100 and the current load thereon.

[0043] For further enhancing the braking control, it is also beneficial to have an accurate knowledge of how the weight of the rail vehicle 100 is distributed over its axles. I.e. only relatively low braking forces can be applied to relatively lightly loaded axles without causing the wheels thereof to slip relative to the tracks, whereas relatively heavily loaded axles can withstand relatively high braking forces before the wheels thereof slip relative to the tracks. Whether for efficiency reasons or to avoid material damage, wheel slip should be avoided as much as possible. Thus, for safety reasons, the estimated minimum axle weight usually determines the maximum braking force allowed for the entire rail vehicle according to known practice. This, of course, results in sub-optimal acceleration / braking performance.

[0044] Thus, the controller 140 is preferably arranged to estimate the different axle weights of the rail vehicle 100. Figure 1Four such axles are illustrated, namely 131, 132, 133, and 134. In response to acceleration control signals A1, A2, and A3 from acceleration controllers 161, 162, and 163, a set of drive units 101, 102, and 103 are configured to apply a corresponding traction force to each axle 131, 132, and 133 in the drive subset of the axles, thereby accelerating the rail vehicle 100.

[0045] In practice, a typical rail vehicle contains far more axles than... Figure 1 As shown. Traditionally, each bogie has two axles, carrying a total of four wheels, and each car body of the rail vehicle 100 includes one bogie at the front and one at the rear.

[0046] exist Figure 1 In the rail vehicle 100, a set of drive units 101, 102 and 103 are configured to apply a corresponding traction force to each of the axles 131, 132 and 133 in the drive subset of the axles.

[0047] Now refer to Figure 4 The controller 140 is configured to acquire the power signal P m The power signal indicates the amount of power generated by the group of drive units 101, 102, and 103 when accelerating the rail vehicle 100 from a first speed v1 to a second speed v2 (e.g., from rest to 10 km / h). However, according to the invention, the power signal P... m The same signal can also be received during acceleration of the rail vehicle 100 between any other two speed levels. In any case, the controller 140 is configured to acquire a speed signal indicating the corresponding values ​​of the first speed v1 and the second speed v2.

[0048] Based on power signal P m In addition to the values ​​of the first speed v1 and the second speed v2, the controller 140 is configured to estimate the total weight m of the rail vehicle 100. tot This can be done under the assumption that any losses in the motor, as well as wind resistance and rolling resistance losses, are negligible, which is largely true at low speeds. That is, under this assumption, all supplied power is converted into the kinetic energy of the rail vehicle, i.e., P. t = W k Where P is the supplied power, t is the time for supplying power, and W is the power supplied. k It is the kinetic energy generated.

[0049] The generated kinetic energy W k This can then be expressed as: W k = m tot v 2 / 2, where v = v2 - v1.

[0050] In other words, the controller 140 can determine the total weight m of the rail vehicle 100 from the total weight m of the rail vehicle 100 and the total weight m of the rail vehicle 100 carried by the driving subset of axles. tot The calculation is:

[0051] Now referring again to Figure 2 , the controller 140 is further configured to: (a) obtain wheel speed signals indicative of respective rotational speeds of the axles 131, 132 and 133 in the driving subset of axles 1, 2 and 3, (b) generate an acceleration control signal Al to a particular drive unit 101 in the set of drive units, such that the drive unit 101 applies an increasing traction force to a particular drive axle (here exemplified as 131) in the set of drive axles, (c) during the generation of the acceleration control signal Al, repeatedly determine the rotational speed of the particular drive axle 131 1 and the average rotational speed of all axles in the driving subset of axles except the particular drive axle (here 132 and 133), a between the absolute difference 1- a ; and in response to the absolute difference 1- a exceeding a threshold value, (d) determine a parameter m reflecting the friction coefficient between the pair of wheels 124a and 124b on the particular axle 131 and the pair of rails 191 and 192 on which the rail vehicle 100 is travelling. e

[0052] Finally, the controller 140 is configured to repeat the above steps (a) to (c) for each axle 131, 132 and 133 in the driving subset, and to estimate a respective fraction mi, m2 and m3 of the total weight m of the rail vehicle 100 carried by each of these axles based thereon. tot

[0053] It is worth mentioning that the above particular drive axle 131 does not have to be any particular axle, such as the foremost or rearmost axle of the rail vehicle 100. Instead, the above procedure can start with any arbitrarily chosen axle in the driving subset.

[0054] ​​Furthermore, it is generally advantageous to perform the above process according to a fixed or dynamic schedule, wherein each axle in the drive subset alternately either represents a specific axle or is included in the complement set, i.e., all axles except the specific axle. Nevertheless, it is beneficial to repeat the process so as to be able to respond to the total weight m during the operation of the rail vehicle 100. tot Any changes and / or total weight m tot The braking function is adjusted by redistributing the brakes across the axles.

[0055] like Figure 1 As shown in axle 134, one or more axles of the rail vehicle 100 may be non-driven, i.e., not included in the driven subsets 131, 132, and 133 of the axles. To handle this situation and thus be able to estimate the axle weight of the non-driven axles, according to one embodiment of the invention, the controller 140 is also configured to perform the following process.

[0056] (e) Acquire wheel speed signals, which indicate the corresponding rotational speeds of the axles 131, 132, 133 and 134 of the rail vehicle 100. 1. 2. 3 and 4; (f) A braking control signal B4 is generated for a braking unit 184 (e.g. via a data bus 150), the braking unit being configured to apply a braking force to a non-drive wheel axle 134, such that the braking unit applies a gradually increasing braking force to the non-drive wheel axle 134. (g) During the generation of braking control signal B4, the rotational speed of the non-drive wheel axle 134 is repeatedly determined. 4. Average rotational speed of all axles 131, 132, and 133 except for the non-driving axle 134. a The absolute difference between them | 4- a │; and in response to the absolute difference exceeding a threshold, preferably but not necessarily related to the above regarding Figure 3 The thresholds are the same. (h) Determine parameters m This parameter reflects the coefficient of friction between a pair of wheels 124a and 124b on a specific axle 134 and a pair of tracks 191 and 192 on which the rail vehicle 100 travels. e , In the typical case where a rail vehicle has more than one non-drive axle, the controller 140 is also configured to repeat steps (e) to (g) for each non-drive axle and estimate the total weight m borne by each non-drive axle based on this. tota corresponding score m4.

[0057] The controller 140 can be configured to generate a control message ctrl A such that the acceleration controllers 161, 162 and 163 generate acceleration control signals Al, A2 and A3 to the drive units 101, 102 and 103, respectively, such that the average drive force applied to the wheel axles 132 and 133, other than the specific wheel axle 131, is gradually increase increased while the drive force applied to the specific wheel axle 131 is gradually decrease decreased. In other words, the drive on the other wheel axles 132 and 133 compensates for the slightly excessive drive force applied to the specific wheel axle 131.

[0058] Preferably, this compensation is matched in time. This means that the controller 140 is configured to generate a control message ctrl A such that the acceleration controllers 161, 162 and 163 generate acceleration control signals Al, A2 and A3 to the drive units 101, 102 and 103, respectively, such that at each instant the gradual decrease of the average drive force applied to the wheel axles 132 and 133, other than the specific wheel axle 131, corresponds to a gradual increase of the drive force applied to the specific wheel axle 131. I.e. the deviation drive force applied to the specific wheel axle 131 is hereby masked by the opposite deviation represented by the drive forces applied to the wheel axles 132 and 133 of the drive subset.

[0059] With reference again to Figure 2 , a drive unit 101 according to an embodiment of the application is seen. The drive unit 101 is configured to receive an acceleration control signal Al from an acceleration controller 161, which in turn operates in response to a control message ctrl A from the controller 140. The acceleration control signal Al can be transmitted, e.g. over a data bus 150. In response to the acceleration control signal Al, the drive unit 101 is configured to drive the wheel axle 131. The drive unit 101 can comprise at least one electric motor, the tractive force of which depends on the size of the current fed into it.

[0060] Figure 4 A block diagram of the controller 140 according to an embodiment of the application is shown. The controller 140 comprises a processing circuit in the form of at least one processor 430 and a storage unit 420, i.e. a non-transitory data carrier, storing a computer program 425, which in turn contains software for causing the at least one processor 430 to perform the actions recited in this disclosure when the computer program 425 is run on the at least one processor 430.

[0061] The controller 140 comprises an input interface configured to receive a brake instruction B, a power signal P mspeed signals indicative of the speeds v1 and v2, respectively, and wheel speed signals indicative of the rotational speeds of the axles 131, 132, 133 and 134 in the driving subset of axles 1, 2, 3 and 4. Furthermore, the controller 140 comprises an output interface configured to provide control signals ctrl A such that the acceleration controller is able to cause the driving units 101, 102 and 103 associated therewith to generate respective tractive forces in response to the acceleration control signals A1, A2 and A3, respectively. Here, the respective tractive forces are based on respective fractions m1, m2 or m3 of the total weight m tot applicable to the associated axle 131, 132 or 133.

[0062] Additionally, the controller 140 comprises an output interface configured to provide an alarm signal A when the braking capacity is recalculated due to the determination that the fault-free (OK) braking units are unable to compensate for the faulty (F) braking units.

[0063] To summarize, and with reference to the flowchart in Figure 5 , now a computer-implemented method for a rail vehicle performed by the controller 140 according to the present application and preferred embodiments thereof will be described.

[0064] In a first step 510, a friction parameter m is determined, which reflects the friction coefficient between at least one wheel of the rail vehicle and at least one rail on which the rail vehicle is travelling e .

[0065] A subsequent step 520 checks whether all braking units meet the operability criterion. If so, step 530 is performed; otherwise, the process continues to step 550.

[0066] Step 530 checks whether a braking instruction has been received. If so, step 540 is performed; otherwise, the process loops back to step 510.

[0067] In step 540, the fault-free braking units are controlled to apply respective braking forces to respective rotating members mechanically connected to wheels of the rail vehicle, thereby reducing the speed of the rail vehicle in accordance with the received braking instruction.

[0068] Step 550 estimates, based on the friction parameter m , whether it is possible to increase the respective braking force of each fault-free braking unit to compensate for the faulty braking units. If such compensation is deemed possible, step 530 is performed; otherwise, the process continues to step 560.

[0069] In step 560, the braking capacity of the track vehicle is recalculated on the basis of the faultless brake units and the adhesion parameters m The braking capacity of the track vehicle is recalculated. Thereafter, the process loops back to step 510.

[0070] Reference is made to Figure 5 All process steps described and any sub-sequences of steps can be controlled by a programmed processor. Furthermore, although the embodiments of the application described above with reference to the drawings comprise a processor and processes performed in at least one processor, the application thus also extends to computer programs, particularly computer programs on or in a carrier, adapted to put the application into practice. The program can be in the form of source code, object code, a code intermediate source and object code such as a partially compiled form, or in any other form suitable to express the instructions described by the application. The program can be supplied to the processor together with the operating system of an apparatus or it can be supplied separately. The carrier can be any entity or device capable of carrying the program. For example, the carrier can comprise a storage medium, such as a flash memory, a ROM (Read Only Memory), for example a DVD (Digital Video / Digital Versatile Disc), a CD (Compact Disc) or a semiconductor ROM, an EPROM (Erasable Programmable ROM), an EEPROM (Electrically Erasable Programmable ROM), or a magnetic recording medium, for example a floppy disc or hard disc. Further, the carrier can be a transmissible carrier such as an electrical or optical signal carrying the computer program, or a carrier suitable for storing such a program, such as a broadcast or other signal on a medium such as a wireless channel. The carrier can be a combination of one or more of the above. The carrier can be a non-transitory carrier. The program can be supplied to the user encoded on one or more data carriers, e.g. one or more floppy disks, CD ROMs or the like. The data carriers can be distributed as standard products, for example as an add-on for a personal computer or the like. Of course, the data carrier(s) and / or the programs supplied on the same can be encoded for different users according to their specific implementation requirements.

[0071] When the term "comprising" is used in the present description and claims, it is to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more additional features, integers, steps, components or groups thereof. The indefinite articles "a" or "an" do not exclude a plurality. The mere fact that different features are recited in mutually different dependent claims does not indicate that combinations of features are not usable. The combination of features in the claims does not limit their protection; the scope of protection provided by a claim is not limited to the features of that claim itself, but is instead determined by the features defined in that claim and their equivalents.

[0072] It should also be noted that the features of the various embodiments described herein can be combined freely unless explicitly stated otherwise.

[0073] Variations of the disclosed embodiments can be understood and effected, without departing from the claimed application, from the content of the figures, the disclosure and the accompanying claims.

[0074] The application is not limited to the embodiments described in the figures, but can vary freely within the scope of the claims.

Claims

1. A controller (140) for controlling braking units (171, 172, 173, 174) of a rail vehicle (100), said controller being configured to: Receive braking command (B) and respond to said braking command. The braking unit controls the application of corresponding braking forces to the corresponding rotating components (111, 112, 113, 114) mechanically connected to the wheels (121a, 121b, 122a, 122b, 123a, 123b, 124a, 124b) of the rail vehicle, thereby reducing the speed of the rail vehicle. For each braking unit (171, 172, 173, 174), the braking unit is repeatedly checked to see if it meets the operability criteria and is considered fault-free (OK), or if it does not meet the operability criteria and is considered faulty (F). Its features are, The braking units (171, 172, 173, 174) are electrically operated, and the controller (140) is configured to: Repeatedly determine adhesion parameters ( m The adhesion parameter reflects the coefficient of friction between at least one of the wheels (121a, 121b) and at least one track (191, 192) on which the rail vehicle (100) travels. e ), Based on the adhesion parameters ( m Estimate whether it is possible to increase the corresponding braking force of each fault-free (OK) braking unit (172, 173, 174) to compensate for any faulty (F) braking unit (171), and if it is estimated that such an increase is possible, respond to braking command (B). The OK braking unit is controlled to apply a corresponding braking force to the corresponding rotating component, and the corresponding braking force is increased to compensate for any faulty braking unit.

2. The controller (140) according to claim 1, wherein, In response to the braking command (B), the controller is configured to control the fault-free (OK) braking unit to apply a correspondingly increased braking force to compensate for any faulty (F) braking unit, until either of the following occurs first: Subsequent inspection revealed that at least one additional braking unit in the braking unit was deemed faulty (F), or Estimate the adhesion parameters that are subsequently determined ( m It is impossible to increase the corresponding braking force of each fault-free (OK) braking unit to compensate for any faulty (F) braking unit.

3. The controller (140) according to claim 2, wherein if a subsequent inspection reveals that at least one additional braking unit among the braking units is deemed faulty (F), the controller is configured to: Based on adhesion parameters ( m Estimate whether it is possible to further increase the corresponding braking force of each fault-free (OK) braking unit to also compensate the at least one additional faulty (F) braking unit, and if it is estimated that such further increase is possible, respond to the braking command (B). The OK braking unit is controlled to apply a corresponding braking force to the corresponding rotating component, and the corresponding braking force is increased to compensate for the additional Faulty (F) braking unit.

4. The controller (140) according to claim 2 or 3, wherein if the estimated adhesion parameter is subsequently determined ( m Since it is impossible to increase the corresponding braking force of each fault-free (OK) braking unit to compensate for any faulty (F) braking unit, the controller is configured as follows: The braking capacity of the rail vehicle (100) is recalculated based on the fault-free (OK) braking unit and the adhesion parameters. m ).

5. The controller (140) according to claim 4, wherein, If the braking capacity is recalculated, the controller is also configured to issue an alarm signal (A).

6. The controller (140) according to any one of the preceding claims, wherein the controller is configured to further base on the total weight (m) of the rail vehicle (100). tot To estimate whether it is possible to increase the corresponding braking force of each fault-free (OK) braking unit to compensate for any faulty (F) braking unit.

7. The controller (140) of claim 6, wherein the controller is configured to estimate the total weight (m) of the rail vehicle (100) based on the following factors. tot ): Power signal (P) m ), which indicates the amount of power generated by a group of drive units (101, 102, 103) in the rail vehicle when accelerating the rail vehicle from a first speed (v1) to a second speed (v2), and A speed signal indicating the corresponding values ​​of the first speed (v1) and the second speed (v2).

8. The controller (140) according to any one of the preceding claims, wherein the controller is configured to: (a) Acquire wheel speed signals, which indicate the corresponding rotational speeds of the axles in the drive sub-groups of the axles (131, 132, 133) of the rail vehicle (100).

1.

2. 3) (b) Controlling a specific drive unit (101) in a set of drive units to generate an acceleration control signal (A1) such that the drive unit applies a gradually increasing traction force to a specific axle (131) in the drive subset of axles (131, 132, 133). (c) During the generation of the acceleration control signal (A1), the rotational speed of the specific axle (131) and the average rotational speed of the axles (132, 133) in the drive subset of the axles, excluding the specific axle, are repeatedly determined. a The absolute difference between () 1- a ); and in response to the absolute difference ( 1- a Exceeding the threshold, (d) Determine the adhesion parameters ( m ).

9. The controller (140) according to any one of the preceding claims, wherein the rail vehicle (100) comprises a total of m braking units, and if the braking command (B) instructs the application of a total braking force of xm to all rotating components, and n braking units malfunction (F), then the controller is configured to: Control each of the mn fault-free braking units to apply a corresponding braking force of x(n+1) / n to each rotating component.

10. A computer-implemented method for controlling braking units (171, 172, 173, 174) of a rail vehicle (100), the method being executed in a processing unit (101) of a controller (100), and the method comprising: Receive braking command (B) and respond to said braking command. The control braking unit applies corresponding braking forces to the corresponding rotating components (111, 112, 113, 114) mechanically connected to the wheels (121a, 121b, 122a, 122b, 123a, 123b, 124a, 124b) of the rail vehicle (100), thereby reducing the speed of the rail vehicle, and For each braking unit, the operation criteria are repeatedly checked to determine whether the braking unit meets the operability criteria and is considered fault-free (OK), or does not meet the operability criteria and is considered faulty (F). Its features are: Repeatedly determine adhesion parameters ( m The parameter reflects the coefficient of friction between at least one of the wheels (121a, 121b) and at least one track (191, 192) on which the rail vehicle (100) travels. e ), Based on the adhesion parameters ( m Estimate whether it is possible to increase the corresponding braking force of each fault-free (OK) braking unit to compensate for any faulty (F) braking unit, and if it is estimated that such an increase is possible, respond to the braking command (B). The OK braking unit is controlled to apply a corresponding braking force to the corresponding rotating component, and the corresponding braking force is increased to compensate for any Faulty (F) braking unit.

11. The method of claim 10, wherein, In response to the braking command (B), the method includes controlling the fault-free (OK) braking unit to apply a correspondingly increased braking force to compensate for any faulty (F) braking unit, until either of the following occurs first: Subsequent inspection revealed that at least one additional braking unit in the braking unit was deemed faulty (F), or Estimate the adhesion parameters that are subsequently determined ( m It is impossible to increase the corresponding braking force of each fault-free (OK) braking unit to compensate for any faulty (F) braking unit.

12. The method according to claim 11, wherein, If subsequent inspections reveal that at least one additional braking unit in the braking unit is deemed faulty (F), the method includes: Based on the adhesion parameters ( m It is estimated whether it is possible to further increase the corresponding braking force of each fault-free (OK) braking unit, thereby also compensating for the at least one additional faulty (F) braking unit, and if it is estimated that such further increase is possible, then in response to a braking command (B). The OK braking unit is controlled to apply a corresponding braking force to the corresponding rotating component, and the corresponding braking force is increased to compensate for the additional faulty (F) braking unit.

13. The method according to claim 11 or 12, wherein, If the estimated value is for the subsequently determined adhesion parameters ( m If it is impossible to increase the corresponding braking force of each fault-free (OK) braking unit to compensate for any faulty (F) braking unit, then the method includes: The braking capacity of the rail vehicle (100) is recalculated based on the fault-free (OK) braking unit and the adhesion parameter. m ).

14. The method according to claim 13, wherein, If the braking capacity is recalculated, the method further includes: Issue an alarm signal (A).

15. The method according to any one of claims 10 to 14, further comprising basing the method on the total weight (m) of the rail vehicle (100). tot To estimate whether it is possible to increase the corresponding braking force of each fault-free (OK) braking unit to compensate for any faulty (F) braking unit.

16. The method of claim 15, further comprising estimating the total weight (m³) of the rail vehicle (100) based on the following factors. tot ): Power signal (P) m ), which indicates the amount of power generated by a group of drive units (101, 102, 103) in the rail vehicle when accelerating the rail vehicle from a first speed (v1) to a second speed (v2), and A speed signal indicating the corresponding values ​​of the first speed (v1) and the second speed (v2).

17. The method according to any one of claims 10 to 16, comprising: (a) Acquire wheel speed signals, which indicate the corresponding rotational speeds of the axles in the drive subset of the axles (131, 132, 133) of the rail vehicle (100).

1.

2. 3) (b) Controlling a specific drive unit (101) in a set of drive units to generate an acceleration control signal (A1), causing the drive unit to apply a gradually increasing traction force to a specific axle (131) in the drive subset of axles (131, 132, 133), (c) During the generation of the acceleration control signal (A1), the rotational speed of the specific axle (131) and the average rotational speed of the axles (132, 133) in the drive subset of the axles, excluding the specific axle, are repeatedly determined. a The absolute difference between () 1- a ); And in response to the absolute difference ( 1- a Exceeding the threshold, (d) Determine the adhesion parameters ( m ).

18. The method according to any one of claims 10 to 17, wherein the rail vehicle comprises a total of m braking units, and if the braking command instructs the application of a total braking force of xm to all rotating components, and n braking units malfunction (F), then the method comprises: Each of the mn fault-free braking units is controlled to apply a corresponding braking force of x(n+1) / n to the rotating component.

19. A computer program (425) capable of being loaded into a non-volatile data carrier (420) communicatively connected to at least one processor (430), the computer program (425) comprising software for performing the method according to any one of claims 10 to 18 when the computer program (425) is run on the at least one processor (430).

20. A non-volatile data carrier (420) comprising the computer program (425) according to claim 19.

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