Controller for estimating individual axle loads of rail vehicle, computer-implemented method thereof, computer program and non-volatile data carrier

Abstract

A rail vehicle (100) has a plurality of axles (131, 132, 133, 134) and a set of brake units (101, 102, 103, 104) that apply respective braking forces to the axles. The power signal (Pm) indicates the power required to accelerate the rail vehicle (100) between the first speed (v1) and the second speed (v2) indicated by the speed signal. Based on this, the total weight (mtot) of the rail vehicle (100) is estimated. The wheel speed signals are indicative of respective speeds ([omega] 1, [omega] 2, [omega] 3, and [omega] 4) of the axles (131, 132, 133, 134). The brake unit (101) gradually applies an increased braking force to the specific wheel axle (131). During braking, an absolute difference (| [omega] 1-[omega] a |) between the rotational speed of the particular axle (131) and the average rotational speed ([omega] a) of the other axles is determined, and in response to the absolute difference exceeding a threshold, the particular axle (131) is braked. A friction parameter ([mu] m) reflecting a friction coefficient ([mu] e) between the wheels (121a, 121b) on the specific axle (131) and the rails (181, 182) on which the rail vehicle (100) travels is determined. A braking process is repeated for each of the axles to estimate a respective portion (m1, m2, mn) of the total weight (mtot) carried by each of the axles.

Description

Technical Field

[0001] The invention generally relates to a safety arrangement for a rail vehicle braking system. In particular, the invention relates to a controller for estimating the individual axle weights of a rail vehicle for achieving enhanced braking of the rail vehicle according to the preamble of claim 1. The invention also relates to a corresponding computer-implemented method, 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] When braking a rail vehicle, it is crucial to have accurate information about the adhesion conditions at the wheel-rail interface, i.e. the applicable dynamic friction coefficient. However, in order to achieve a truly effective slowing down of the rail vehicle, it is also important to know how the weight of the rail vehicle is distributed on its wheel axles. That is, only relatively low braking forces can be applied to relatively lightly loaded axles to prevent their wheels from starting to slip on the rails, while relatively heavily loaded axles can withstand relatively high braking forces before their wheels start to slip on the rails. For efficiency reasons and in order to avoid material damage (mainly wheel damage), wheel slip should be avoided as much as possible. Therefore, in many cases, for safety reasons, the estimated minimum axle weight can determine the maximum braking force that can be applied by the rail vehicle. Of course, this leads to a less than ideal overall braking performance.

[0004] Various attempts have been made to determine the gross weight of a vehicle. For example, US 9,358,846 describes a load estimation system and method for estimating the load of a vehicle. The system includes: a tire rotation counter for generating a rotation count based on the rotation of the tire; a device for measuring the distance traveled by the vehicle; an effective radius calculator for calculating the effective radius of the tire based on the distance traveled and the rotation count; and a load estimation calculator for calculating the load carried by the vehicle tire based on the effective radius of the tire. Based on the estimate of the effective radius of each tire and the load carried by each tire calculated from the corresponding effective radius, a center of gravity height estimate can be made based on the estimated total load carried by the tires supporting the vehicle.

[0005] US 9,500,514 shows a method and system for estimating the weight of a vehicle based on at least two forces acting on the vehicle. These forces are the prime mover and at least one other force, and topographic information of the relevant road section. When at least two forces are dominated by the prime mover, the estimation is performed.

[0006] US 9,211,879 discloses an apparatus and a method for arranging sensors on the axles of a rail vehicle to determine its mass. For example, the output signal of an acceleration sensor arranged on the axle of the rail vehicle is evaluated. The mass of the wagon can be determined by the way it vibrates after an impact (switch impact over a switch), which vibration pattern has a typical quality (frequency, amplitude). The direction and intensity of the impact can be determined by the acceleration sensor on the axle (axle), and the vibration can be determined by the same acceleration sensor or another sensor on the chassis. From the measurement data, the mass of the wagon and the mass of the load with a known empty weight can be determined and the load state can be determined from this.

[0007] The above documents describe different strategies for determining the weight and other characteristic properties of a vehicle. However, there is no satisfactory solution for determining how the total weight of a vehicle is distributed among its axles, so that, for example, the braking of the vehicle can be improved. Summary of the invention

[0008] The object of the present invention is to solve the above mentioned problems and to provide a solution which allows to determine the individual axle weights of a rail vehicle in an accurate and reliable manner.

[0009] According to one aspect of the present invention, the object is achieved by a controller for estimating the weight of each axle of a rail vehicle, the rail vehicle having a plurality of axles and a set of brake units, the set of brake units being configured to apply a corresponding braking force to each of the axles to slow down the rail vehicle. The controller is configured to obtain a power signal and a speed signal. The power signal indicates the amount of power generated by an onboard motor to accelerate the rail vehicle from a first speed to a second speed. The speed signal indicates the respective values ​​of the first speed and the second speed. Based on the power signal and the speed signal, the controller is configured to estimate the total weight of the rail vehicle. The controller is also configured to:

[0010] (a) obtaining a wheel speed signal indicating a corresponding rotational speed of the wheel axle,

[0011] (b) generating a brake control signal for a specific brake unit in the set of brake units, so that the brake unit applies a gradually increasing braking force to the specific wheel axle in the wheel axle,

[0012] (c) repeatedly determining an absolute difference between the rotational speed of the particular axle and an average rotational speed of axles other than the particular axle during generation of the brake control signal, and in response to the absolute difference exceeding a threshold:

[0013] (d) determining a parameter reflecting the coefficient of friction between a pair of wheels on a particular axle and a pair of rails on which a rail vehicle travels,

[0014] Steps (a) to (c) are repeated for each of the axles of the rail vehicle and based thereon a respective portion of the total weight carried by each of the axles is estimated.

[0015] The controller described above is advantageous because it provides accurate values ​​for the total weight of the rail vehicle as well as the weights of the individual axles. As an additional effect, this also enables the rail vehicle to be accelerated without the risk of slipping.

[0016] Furthermore, the proposed controller is beneficial because it allows dynamic adaptation of the brake functionality in response to a redistribution of the load during travel (e.g. due to passengers moving around). More importantly, the operation of the brakes can be fully adjusted in a very convenient manner whenever cargo is loaded and / or unloaded.

[0017] According to one embodiment of this aspect of the invention, the controller comprises at least one interface configured to receive a first vector signal and a second vector signal. The first vector signal expresses the acceleration of the rail vehicle, for example, the lateral acceleration and the vertical acceleration. The second vector signal represents the corresponding rotational movement of the wheels on each axle of the rail vehicle. Thus, the rotational movement is performed in a plane orthogonal to the corresponding rotation axis of the axle. The controller is configured to obtain a wheel speed signal indicating the corresponding rotational speed based on the first vector signal and the second vector signal. Thus, an accurate value of the wheel speed can be derived without any tachometer. This in turn ensures a robust and reliable measurement.

[0018] Preferably, the first vector signal also expresses an inclination angle of the rail vehicle relative to a horizontal plane. That is, this enables the controller to adjust the power signal indicating the amount of power generated by the onboard motor and / or the speed signal indicating the second speed based on the inclination angle when estimating the total weight of the rail vehicle. Such an adjustment is necessary if the total weight of the rail vehicle is estimated when the rail vehicle is traveling on non-level ground, because when going uphill, part of the motor power is converted into potential energy, and conversely, when going downhill, part of the kinetic energy is derived from the potential energy.

[0019] According to another embodiment of this aspect of the invention, the controller is configured to provide the respective portion of the total weight to the brake controller so that the brake controller can generate a respective braking force signal for each brake unit in the set of brake units. Thus, the respective braking force signal can be based on the respective portion of the total weight, and the rail vehicle can be slowed down in an optimized manner.

[0020] Preferably, in view of the above, the controller is located at the same location as the brake controller. For example, the controller can be integrated into the brake controller, or vice versa.

[0021] According to a further embodiment of this aspect of the invention, the controller is configured to transmit the brake control signal via a data bus in the rail vehicle. This enables a cost-effective and flexible implementation.

[0022] According to another aspect of the present invention, the object is achieved by a computer-implemented method for estimating the weight of each axle of a rail vehicle, the rail vehicle having a plurality of axles and a set of brake units configured to apply a corresponding braking force to each of the axles to slow the rail vehicle, the method being performed in at least one processor and involving: obtaining a power signal indicating the amount of power generated by an onboard motor to accelerate the rail vehicle from a first speed to a second speed; obtaining a speed signal indicating respective values ​​of the first speed and the second speed; and estimating the total weight of the rail vehicle based on the power signal and the speed signal. The method also involves:

[0023] (a) obtaining a wheel speed signal indicating a corresponding rotational speed of the wheel axle,

[0024] (b) generating a brake control signal for a specific brake unit in the set of brake units, so that the brake unit applies a gradually increasing braking force to a specific one of the wheel axles,

[0025] (c) repeatedly determining an absolute difference between the rotational speed of the particular axle and an average rotational speed of axles other than the particular axle during generation of the brake control signal, and in response to the absolute difference exceeding a threshold:

[0026] (d) determining a parameter reflecting the coefficient of friction between a pair of wheels on a particular axle and a pair of rails on which a rail vehicle travels,

[0027] Steps (a) to (c) are repeated for each of the axles and based thereon the respective portion of the total weight carried by each of the axles is estimated.

[0028] The advantages of the method as well as its preferred embodiments will be apparent from the above discussion with reference to the proposed controller.

[0029] 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.

[0030] According to another aspect of the invention, the object is achieved by a non-volatile data carrier comprising the above-mentioned computer program.

[0031] 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

[0032] The invention will now be explained in more detail by means of preferred embodiments disclosed as examples and with reference to the accompanying drawings.

[0033] Figure 1 Schematically illustrates a rail vehicle equipped with a controller according to one embodiment of the present invention;

[0034] Figure 2 A brake unit according to an embodiment of the present invention is shown;

[0035] Figure 3 shows a graph illustrating an example of coefficient of friction as a function of wheel slip;

[0036] Figure 4 schematically illustrates an accelerometer according to an embodiment of the present invention;

[0037] Figure 5 A block diagram of a controller according to one embodiment of the present invention is shown; and

[0038] Figure 6 The general method according to the invention is illustrated with the aid of a flow chart. DETAILED DESCRIPTION

[0039] exist Figure 1 In FIG. 1 , a schematic diagram of a rail vehicle 100 equipped with a controller 140 according to one embodiment of the present invention can be seen.

[0040] The controller 140 is arranged to estimate individual axle weights of a rail vehicle 100 having a plurality of axles. Figure 1 Four such axles are illustrated in the form of 131, 132, 133 and 134, respectively. Typically, in practice, a rail vehicle comprises a greater number of axles. Traditionally, each bogie has two axles that together carry four wheels, and each body of the rail vehicle 100 includes a respective bogie at the front and rear ends.

[0041] The rail vehicle 100 also includes a set of brake units 101, 102, 103 and 104, which are respectively configured to apply a corresponding braking force to each of the wheel axles 131, 132, 133 and 134. Therefore, by operating the brake units 101, 102, 103 and 104, the rail vehicle 100 can be slowed down.

[0042] Reference now Figure 5 , the controller 140 is configured to obtain a power signal P m , which power signal indicates the amount of power generated by the onboard motor to accelerate 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 present invention, the power signal P may of course also be received during acceleration between any other two speed levels. m In any case, the controller 140 is configured to obtain speed signals indicative of respective values ​​of the first speed v1 and the second speed v2.

[0043] Based on the power signal P m and 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 .

[0044] This can be done assuming that any losses in the motor and losses due to wind and rolling resistance are negligible (which is essentially true at low speeds). That is, if this is the case, then all supplied power is converted into kinetic energy of the rail vehicle, i.e., P·t=W k , where P is the power supplied, t is the time the power has been supplied, and W k is the kinetic energy generated.

[0045] The kinetic energy generated W k Then it can be expressed as:

[0046] W k =m tot ·v 2 / 2, where v = v2 – v1.

[0047] In other words, the controller 140 can calculate the total weight m of the rail vehicle 100. tot Calculated as:

[0048]

[0049] Now also refer to Figure 2 , the controller 140 is further configured to:

[0050] (a) obtaining wheel speed signals indicating the respective rotational speeds ω1, ω2, ω3 and ω4 of the wheel axles 131, 132, 133 and 134,

[0051] (b) generating a brake control signal B1 to a specific brake unit 101 in the set of brake units, so that the brake unit 101 applies a gradually increasing braking force to a specific wheel axle (here illustrated by 131) in the rail vehicle 100;

[0052] (c) repeatedly determining the rotation speed of the specific wheel axle 131 and the average rotation speed ω of all wheel axles of the rail vehicle 100 except the specific wheel axle 131 during the generation of the brake control signal B1 a The absolute difference between ω1–ω a │, and responds to the absolute difference │ω1–ω a │ Exceeding the threshold:

[0053] (d) determining a coefficient μ reflecting the friction between a pair of wheels 121a and 121b respectively on a specific wheel axle 131 and a pair of rails 181 and 182 on which the rail vehicle 100 travels e The parameter μ m .

[0054] Figure 3 The dynamic friction coefficient μ is shown k An example of how this can be expressed as a function of the wheel slip s, which is understood here to indicate the sliding motion of the wheel relative to the track. However, technically, the wheel slip s can just as well express the rotational motion of the wheel relative to the track. In other words, the wheel slip s is applicable to slowing down scenarios as well as to speeding up scenarios.

[0055] Typically, for lower values, the dynamic friction coefficient μ k As the wheel slip s increases, it increases relatively proportionally. However, when approaching the peak μ e , the dynamic friction coefficient μ k After passing the peak value, the dynamic friction coefficient μ k The friction coefficient is essentially constant for all values ​​of wheel slip s. Therefore, the peak value μ e With optimal wheel slip e After this, a further increase in the wheel slip s leads to a dynamic friction coefficient μ k Gradually decreases and then remains almost constant.

[0056] According to the invention, a parameter μ that reflects the coefficient of friction between the wheels of the rail vehicle 100 and the rails 181 and 182 on which the rail vehicle 100 travels is determined. m Ideally, the peak value μ should be eFor example, the peak value μ can be obtained as follows e When the rotation speed of the specific wheel axle 131 is equal to the average rotation speed ω of all wheel axles of the rail vehicle 100 except the specific wheel axle 131 a The absolute difference between ω1–ω a When the threshold is exceeded, this corresponds to the wheels 121a and 121b on the particular axle 131 experiencing the optimum wheel slip s e Nearby wheel slip m The dynamic friction coefficient μ k It is given by the following expression:

[0057]

[0058] Where F is the force applied by the brake unit,

[0059] m tot is the gross weight of the rail vehicle 100, and

[0060] g is the standard acceleration due to gravity.

[0061] Assuming wheel slip s m is at optimum wheel slip e In the case of near k The peak value μ e ; and wheel slip s m With optimal wheel slip e The closeness is determined by the rotation speed of the specific axle 131 and the average rotation speed ω of all axles of the rail vehicle 100 except the specific axle 131. a The absolute difference between ω1–ω a │The threshold is used to ensure this.

[0062] Finally, the controller 140 is configured to repeat steps (a) to (c) for each axle 131, 132, 133, and 134 of the rail vehicle 100, and estimate the total weight m based thereon. tot The corresponding parts m1, m2, ..., m carried by each of these axles n .

[0063] It is worth mentioning that the specific axle 131 does not need to be any particular axle, for example, the frontmost or rearmost axle of the rail vehicle 100. Instead, the above process can start from any selected axle in the rail vehicle 100.

[0064] Furthermore, it is often advantageous to perform the above process according to a fixed or dynamic schedule, wherein each axle in the rail vehicle 100 alternately represents a specific axle or is included in the complement (i.e., all axles except the specific axle). However, it is beneficial to repeat the process in response to the total weight m. tot Any changes and / or total weight m tot Redistribution on the axle to adjust the braking function.

[0065] The controller 140 may be configured to generate control signals B1, B2, B3, and B4 to the brake units 101, 102, 103, and 104, respectively, so that when the braking force applied to the specific axle 131 gradually increases, the average braking force applied to the axles 132, 133, and 134 other than the specific axle 131 gradually decreases. In other words, the braking on the other axles 132, 133, and 134 compensates for the slightly excessive force applied to the specific axle 131.

[0066] Preferably, such compensation is matched in time. This means that the controller 140 is configured to generate the control signals B1, B2, B3 and B4 so that at each point in time, a gradual decrease in the average braking force applied to the axles 132, 133 and 134 other than the specific axle 131 corresponds to a gradual increase in the braking force applied to the specific axle 131. That is, therefore, the deviating braking force applied to the specific axle 131 is masked by the opposite deviation represented by the braking force applied to the axles 132, 133 and 134 other than the specific axle 131.

[0067] Reference again Figure 2 , it can be seen that the brake unit 101 according to one embodiment of the present invention. The brake unit 101 is configured to receive a control signal, such as a brake command B1, from the controller 140 via a data bus 150. In response, the brake unit 101 is configured to perform a braking action. The brake unit 101 may include a rotatable member 111, a first pressing member and a second pressing member (represented here by symbol 211), a brake actuator 220, a gear assembly (not shown) and a motor 230. The rotatable member 111, which may be represented by a brake disc or a brake drum, is mechanically connected to at least one wheel 121 of the rail vehicle 100. Specifically, in response to the brake command B1, the brake actuator 220 is preferably configured to generate a braking force signal BF1 to the motor 230, which in turn causes the motor 230 to move the first pressing member and the second pressing member 211 relative to the rotatable member 111.

[0068] It should be noted that according to the present invention, the electric motor 230 may be replaced by a pneumatically operated piston and cylinder arrangement configured to actuate the first and second pressing members 211 .

[0069] Furthermore, for overall efficiency, the data bus 150 may of course be configured to transmit all control signals B1 , B2 , B3 and B4 from the controller 140 to each brake unit in the set of brake units 101 , 102 , 103 and / or 104 .

[0070] Each of the first and second pressing members 211 is configured to move relative to the rotatable member 111 to perform a braking action. Typically, the braking action involves applying a specific braking force on the rotatable member 111. However, the braking action may also involve reducing or releasing an already applied braking force.

[0071] Reference now Figure 4 and Figure 5 According to one embodiment of the present invention, the controller 140 includes at least one interface 511 and 512, which is configured to receive a first vector signal VS1 and a second vector signal VS2, respectively. The first vector signal VS1 expresses the acceleration a of the rail vehicle 100 in at least one dimension. X 、a Y 、a Z 、a R 、a P and / or a W , for example, linear acceleration in one or more spatial directions and / or rotation about one or more of these directions. The second vector signal VS2 expresses the respective rotational motion of the wheels 121a, 121b; 122a, 122b; 123a, 123b and 124a, 124b on each axle. Thus, since each wheel is configured to rotate about a respective one of the axles, the rotational motion is performed in a plane orthogonal to the respective axis of rotation of the axle.

[0072] The controller 140 is configured to obtain wheel speed signals indicating the corresponding rotational speeds ω1, ω2, ω3 and ω4 based on the first vector signal VS1 and the second vector signal VS2 by applying a physical mechanics algorithm known in the art. Of course, once each of the individual rotational speeds ω1, ω2, ω3 and ω4 is known, the average rotational speed ω a It's insignificant.

[0073] Figure 4 A first accelerometer 425 according to an embodiment of the invention is schematically shown. The first accelerometer 425 is arranged in a frame element 110 of a rail vehicle 100. The first accelerometer 425 is configured to generate a first vector signal VS1 representing the acceleration of the rail vehicle 100 in at least one dimension, typically in three spatial directions a X 、a Y and a ZThe acceleration in each of the directions and the corresponding rotation a about an axis along each of these directions R 、a P and a W .

[0074] Preferably, according to an embodiment of the present invention, the first vector signal VS1 also expresses the inclination angle α of the rail vehicle 100 relative to the horizontal plane H. Here, the controller 140 is configured to estimate the total weight m of the rail vehicle 100 tot When the power signal P indicating the amount of power generated by the onboard motor is adjusted based on the tilt angle α m and / or a speed signal indicating a second speed v2. Therefore, if the power signal P is obtained m and speed signal, the rail vehicle 100 is traveling on a non-level ground, the total weight m can be fully adjusted tot The estimated value of is such that the portion of the motor power converted into potential energy is discarded when going uphill; and conversely, the portion of the kinetic energy derived from the potential energy is discarded when going downhill.

[0075] Naturally, for the same reason, it is also preferred that when the above steps (a) to (c) are repeated to estimate the total weight m tot The corresponding parts m1, m2, ..., m2 carried by each axle 131, 132, 133 and 134 of the rail vehicle 100 n , compensate for the tilt angle α.

[0076] Figure 2 A second accelerometer 235 is shown that is eccentrically arranged relative to the rotation axis of at least one wheel, such as 121. The second accelerometer 235 is configured to generate a second vector signal VS2 that expresses the movement of the second acceleration sensor 235 in a plane orthogonal to the rotation axis of at least one wheel 121, and the second accelerometer transmits a signal containing the second vector information VS2 to the controller 140.

[0077] Figure 5 A block diagram of a controller 140 according to one embodiment of the present invention is shown. The controller 140 comprises a processing circuit in the form of at least one processor 530 and a storage unit 520 (i.e., a non-volatile data carrier) storing a computer program 525, which in turn contains software for causing the at least one processor 530 to perform the actions mentioned in the present disclosure when the computer program 525 is run on the at least one processor 530.

[0078] The controller 140 includes an input interface configured to receive the first vector signal VS1, the second vector signal VS2 and the power signal P mand speed signals representing the speeds v1 and v2, respectively. In addition, the controller 140 includes outputs configured to provide control signals B1, B2, B3 and B4 information about the weight of each axle, such as the total weight m tot The corresponding parts m1, m2, ..., m n As mentioned above, one or more of the input signals and / or the output signals may be transmitted via the data bus 150 .

[0079] According to one embodiment of the present invention, the controller 140 is configured to provide a total weight m to each brake controller 161, 162, 163 and 164. tot The corresponding parts m1, m2, ..., m n , so that the brake controller can enable its associated brake actuator 220 to generate a corresponding appropriate braking force signal BF1. The appropriate braking force signal BF1 is based on the total weight m tot The braking force signal applicable to the corresponding part m1 of the wheel axle in question (such as 131).

[0080] According to one embodiment of the present invention, the controller 140 is co-located with the brake controller. Thus, for example, the controller 140 may be integrated into the brake controller 161, or vice versa. Alternatively, the functionality of the controller 140 may be distributed across two or more of the brake controllers 161, 162, 163, and / or 164.

[0081] To summarize and refer to Figure 6 Referring to the flowchart in FIG. 1 , a computer-implemented method for a rail vehicle performed by the controller 140 will now be described.

[0082] In a first step 605, signals are obtained expressing a first speed v1 and a second speed v2 and an amount of power generated by a motor on the rail vehicle 100 to accelerate the rail vehicle from the first speed v1 to the second speed v2.

[0083] In the following step 610 , a speed signal is obtained, which indicates the rotation speed ω1 of a specific axle (such as 131 ) among the axles of the rail vehicle 100 .

[0084] In step 615, which is preferably substantially parallel to step 610, an average value is obtained, which represents the average value ω of the rotational speeds ω2, ω3 and ω4 of the axles 132, 133 and 134 of the rail vehicle 100 except for the specific axle 131. a .

[0085] In step 620 , subsequent to step 610 and preferably substantially in parallel with step 615 , a brake control signal is generated, the brake control signal being configured to cause the brake unit to apply an increased braking force to the specific wheel axle 131 .

[0086] Thereafter, step 625 checks the rotation speed of the specific axle 131 with the average rotation speed ω of the axles other than the specific axle a The absolute difference between ω1–ω a │Whether it exceeds the threshold. If yes, then the next step is step 630. Otherwise, the process loops back to steps 610 and 615.

[0087] In step 630, the friction coefficient μ between the wheels 121a and 121b on the particular axle 131 and the rails 181 and 182 on which the rail vehicle 100 travels is determined. e The parameter μ m .

[0088] Subsequently, step 635 checks whether all axles 131, 132, 133 and 134 of the rail vehicle 100 have been tested. If yes, the process ends. If not, the process continues to step 640, in which an axle that has not yet been tested is selected.

[0089] Then, in step 645 , a speed signal is obtained, which is indicative of the rotation speed ω1 of the selected axle.

[0090] In step 650, which is preferably substantially parallel to step 645, an average value is obtained, which represents the average value of the rotational speeds of the axles of the rail vehicle 100 other than the selected axle ω a .

[0091] In step 655 subsequent to step 645 and preferably substantially in parallel with step 650 , a brake control signal is generated that is configured to cause the brake unit to apply an increased braking force to the selected wheel axle.

[0092] Thereafter, step 660 checks the rotational speed of the selected axle with the average rotational speed ω of the axles other than the selected axle. a Whether the absolute difference between exceeds the threshold. If so, the next step is step 665. Otherwise, the process loops back to steps 645 and 650.

[0093] In step 665, the total weight m is estimated. tot The corresponding part carried by the selected axle in the wheel is determined. Thereafter, the process loops back to step 635. It should be noted that when the corresponding parts on all other axles have been determined, the total weight m tot The portion of the mass carried by the first wheel axle can be determined as the total mass m tot the remainder of .

[0094] refer to Figure 6All 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 an optical signal that can be transmitted via a cable or an optical cable or by radio or 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.

[0095] When used in this specification, the term "comprising" is used to specify the presence of stated features, integers, steps or components. The term does 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 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.

[0096] 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.

[0097] 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.

[0098] 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. A controller (140) for estimating the weight of each axle of a rail vehicle (100), the rail vehicle comprising a plurality of axles (131, 132, 133, 134) and a set of brake units (101, 102, 103, 104), the set of brake units being configured to apply a corresponding braking force to each of the axles (131, 132, 133, 134) to slow down the rail vehicle (100), the controller (140) being configured to obtain: Power signal (P m ), the power signal indicating an amount of power generated by an onboard motor to accelerate the rail vehicle (100) from a first speed (v1) to a second speed (v2), a speed signal indicating respective values ​​of the first speed (v1) and the second speed (v2), and estimating a total weight (m) of the rail vehicle (100) based on the power signal and the speed signal. tot ), characterized in that The controller (140) is also configured to: (a) obtaining wheel speed signals indicating respective rotational speeds (ω1, ω2, ω3 and ω4) of the wheel axles (131, 132, 133, 134), (b) generating a braking control signal (B1) for a specific braking unit (101) in the group of braking units, so that the braking unit applies a gradually increasing braking force to a specific wheel axle (131) in the wheel axle, (c) repeatedly determining the rotation speed of the specific wheel axle (131) and the average rotation speed (ω) of the wheel axles other than the specific wheel axle during the generation of the brake control signal (B1); a ) between the absolute difference (│ω1–ω a │), and in response to the absolute difference exceeding a threshold: (d) determining a coefficient of friction (μ) between a pair of wheels (121a, 121b) on the specific wheel axle (131) and a pair of rails (181, 182) on which the rail vehicle (100) travels; e ) parameters (μ m ), Repeat steps (a) to (c) for each of the axles and estimate the total weight (m tot ) carried by each of the axles (m1, m2, m n ).

2. The controller (140) according to claim 1, comprising at least one interface (511, 512), the at least one interface being configured to receive a first vector signal (VS1) and a second vector signal (VS2), wherein: The first vector signal (VS1) expresses the acceleration (a) of the rail vehicle (100) in at least one dimension. X 、a Y 、a Z 、a R 、a P 、a W ),and The second vector signal (VS2) expresses the respective rotational motion of the wheels (121a, 121b; 122a, 122b; 123a, 123b; 124a, 124b) on each of the axles (131, 132, 133, 134), the rotational motion being performed in a plane orthogonal to the respective rotational axis of the axles, and The controller (140) is configured to obtain the wheel speed signal indicating the corresponding rotation speed (ω1, ω2, ω3, ω4) based on the first vector signal (VS1) and the second vector signal (VS2).

3. The controller (140) according to claim 2, wherein the first vector signal (VS1) further expresses an inclination angle (α) of the rail vehicle (100) relative to a horizontal plane (H), and the controller (140) is configured to estimate the total weight (m tot ), adjusting the power signal (P) indicating the amount of power generated by the onboard motor based on the tilt angle (α) m ) and at least one of the speed signals indicating the second speed (v2).

4. A controller (140) according to any one of the preceding claims, wherein the controller (140) is configured to provide the total weight (m tot ) of the corresponding part (m1, m2, m n ), so that the brake controller can generate a corresponding braking force signal (BF1) for each brake unit (101) in the group of brake units (101, 102, 103, 104), wherein the corresponding braking force signal (BF1) is based on the total weight (m tot ) of the corresponding part (m1, m2, m n ).

5. The controller (140) according to claim 4, wherein the controller (140) and the brake controller (161, 162, 163, 164) are located at the same location.

6. A controller (140) according to any of the preceding claims, wherein the controller (140) is configured to transmit the brake control signal (B1, B2, B3, B4) via a data bus (150) in the rail vehicle (100).

7. A computer-implemented method for estimating individual axle weights of a rail vehicle (100), the rail vehicle comprising a plurality of wheel axles (131, 132, 133, 134) and a set of brake units (101, 102, 103, 104), the set of brake units being configured to apply a respective braking force to each of the wheel axles (131, 132, 133, 134) to slow the rail vehicle (100), the method being executed in at least one processor (530) and comprising: Get the power signal (P m ), the power signal indicating an amount of power generated by an onboard motor to accelerate the rail vehicle (100) from a first speed (v1) to a second speed (v2), obtaining a speed signal indicating respective values ​​of the first speed (v1) and the second speed (v2), and based on the power signal and the speed signal, Estimate the total weight (m) of the rail vehicle (100) tot ), Features: (a) obtaining wheel speed signals indicating respective rotational speeds (ω1, ω2, ω3 and ω4) of the wheel axles (131, 132, 133, 134), (b) generating a braking control signal (B1) for a specific braking unit (101) in the group of braking units, so that the braking unit applies a gradually increasing braking force to a specific wheel axle (131) in the wheel axle, (c) repeatedly determining the rotation speed of the specific wheel axle (131) and the average rotation speed (ω) of the wheel axles other than the specific wheel axle during the generation of the brake control signal (B1); a ) between the absolute difference (│ω1–ω a │), and in response to the absolute difference exceeding a threshold: (d) determining a coefficient of friction (μ) between a pair of wheels (121a, 121b) on the specific wheel axle (131) and a pair of rails (181, 182) on which the rail vehicle (100) travels; e ) parameters (μ m ), Steps (a) to (c) are repeated for each of the axles, and based thereon, Estimated total weight (m tot ) carried by each of the axles n ).

8. The method according to claim 7, comprising: A first vector signal (VS1) and a second vector signal (VS2) are received via at least one interface (511, 512), wherein the first vector signal (VS1) expresses the acceleration (a) of the rail vehicle (100) in at least one dimension. X 、a Y 、a Z 、a R 、a P 、a W ), the second vector signal (VS2) expresses the respective rotational motion of the wheels (121a, 121b; 122a, 122b; 123a, 123b; 124a, 124b) on each of the wheel axles (131, 132, 133, 134), the rotational motion being performed in a plane orthogonal to the respective rotational axis of the wheel axles, and The wheel speed signals indicating the respective rotational speeds (ω1, ω2, ω3, ω4) are obtained based on the first vector signal (VS1) and the second vector signal (VS2).

9. The method according to claim 8, wherein the first vector signal (VS1) further expresses an inclination angle (α) of the rail vehicle (100) relative to a horizontal plane (H), and the method comprises: In estimating the total weight (m tot ), adjusting the power signal (P) indicating the amount of power generated by the onboard motor based on the tilt angle (α) m ) and at least one of the speed signals indicating the second speed (v2).

10. The method according to any one of claims 7 to 9, further comprising: Provide the total weight (m tot ) of the corresponding part (m1, m2, m n ), so that the brake controller can generate a corresponding braking force signal (BF1) for each brake unit (101) in the group of brake units (101, 102, 103, 104), wherein the corresponding braking force signal (BF1) is based on the total weight (m tot ) of the corresponding part (m1, m2, m n ).

11. The method according to any one of claims 7 to 10, comprising: The brake control signals (B1, B2, B3, B4) are transmitted via a data bus (150) in the rail vehicle (100).

12. A computer program (525) loadable into a non-volatile data carrier (520) communicatively connected to at least one processor (530), the computer program (525) comprising software for performing a method according to any one of claims 10 to 16 when the computer program (525) is run on the at least one processor (530).

13. A non-volatile data carrier (520) comprising a computer program (425) according to claim 12.

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