VEHICLE WITH A SENSOR ARRAY FOR MEASURING AN ADJUSTING ANGLE OF THE ADJUSTING ELEMENT, MEASURING ARRAY AND MEASURING METHOD

Description

[0001] The invention relates to a vehicle with a rotationally movable actuating element and with a sensor arrangement for measuring an actuating angle of the actuating element. Furthermore, the invention relates to a method for measuring the actuating angle of a rotationally movable actuating element in a vehicle, in which a sensor arrangement for measuring the actuating angle is used. Furthermore, the invention relates to a measuring arrangement configured to carry out a measuring method. Finally, the invention relates to a computer program product and a device for providing this computer program product, wherein the computer program product is equipped with program instructions for carrying out this method. Document US3897979A describes an inertia- and gravity-sensitive trailer brake control system without a reference acceleration sensor.

[0002] Vehicles have a variety of control elements whose function must be checked for any faults. This is especially true for brakes, as these are safety-relevant components of the vehicle. Brake pads are subject to wear and tear, so they must be replaced when a wear limit is reached. Furthermore, brakes can malfunction; in particular, a brake pad or a brake block supporting the brake pad can become lost, impairing the brake's function.

[0003] For example, before freight trains depart, the wagon's braking system is checked to ensure it is functioning properly. This check includes checking whether all brake blocks on the freight wagons (vehicles) are present, whether the linings are still sufficiently thick, and whether the brakes can be applied and released.

[0004] Checking whether all brake blocks on a freight car are present and have sufficient pad thickness is currently typically performed by a manual visual inspection by the car inspector upon dispatching a train. Equipping the brake pads with wear sensors, as is done in passenger cars, for example, is not done in freight cars for cost reasons. This is due not least to the fact that the number of brake pads used in a freight car far exceeds that of a passenger car.

[0005] CA 2652618 A1 describes a sensor arrangement for trucks that can monitor the function of a braking system. This is done by detecting the angle of an actuator used to actuate the brakes.

[0006] Document DE 10 2013 222 201 A1 describes a sensor arrangement for detecting pedal movement in a vehicle, comprising an evaluation and control unit and at least one at least two-channel measuring sensor moved with the pedal. A reference sensor with at least two channels is fixedly mounted in the vehicle.

[0007] The object of the invention is to provide a vehicle with a rotationally movable actuating element, for example, an actuating element for a brake, or a sensor arrangement for such an actuating element, which can be operated as reliably as possible with minimal maintenance effort. Furthermore, the object of the invention is to provide a method that can be used to operate such a vehicle with minimal maintenance effort and high reliability. Furthermore, the object of the invention is to provide a computer program product and a device for providing this computer program product, with which the aforementioned method can be carried out.

[0008] This object is achieved according to the invention with the subject matter of the claim (vehicle) specified at the outset in that the sensor arrangement comprises a measuring acceleration sensor, which is attached to the actuating element, and a reference acceleration sensor, which is immovably attached to the vehicle. Furthermore, the sensor arrangement is configured to generate angle measurement data dependent on the setting angle (α) and the vehicle position, taking into account the direction of the acceleration due to gravity (g), and to generate measurement error measurement data dependent on the vehicle position, taking into account the direction of the acceleration due to gravity (g), to calculate the setting angle (α) from the angle measurement data taking into account the measurement error measurement data, and to calculate at least one stop value for the control element (STE) as the setting angle (α), which is measured when an increase in the setting angle (α) is prevented by a stop.

[0009] The fact that the reference acceleration sensor is immovably mounted on the vehicle means that it is stationary with respect to a coordinate system firmly connected to the vehicle. "Stationary" in the context of the invention means that the reference acceleration sensor does not undergo any rotation of the actuator or any other movement relative to the vehicle (at least during the measurement).

[0010] In contrast, the measuring acceleration sensor is fixedly mounted on the actuator, meaning that the actuator is stationary with respect to a coordinate system connected to the actuator. However, this also means that when the actuator rotates, the acceleration sensor rotates together with the actuator, which can be described in a coordinate system fixedly connected to the vehicle and in a global coordinate system fixed to the Earth.

[0011] The measuring acceleration sensor determines the angle of the actuator relative to the Earth's gravity vector (aligned to the Earth's center) by measuring Earth's gravity, preferably along three orthogonal spatial axes (e.g., the global coordinate system; more on this below). It is therefore only suitable for levers whose angle does not change parallel to the Earth's surface, i.e., with a vertical axis of rotation.

[0012] An angular offset of the rotation axis greater than 0° relative to the vertical of the vehicle is therefore a prerequisite for the functioning of the measuring acceleration sensor. This means that the rotation axis of the rotationally mounted actuator must be inclined relative to the vertical of the vehicle, i.e., it must have an inclination angle greater than 0°, preferably greater than 30°, and even more preferably greater than 60°. A change in the measured acceleration can only be determined due to a change in the actuation angle if the acceleration due to gravity acts on the acceleration sensor at a different angle due to the rotation of the actuator.

[0013] The vertical axis of the vehicle refers to an imaginary axis that is precisely vertical when the vehicle is on a horizontal surface. This means that the vertical axis, in this case, corresponds exactly to the direction of the acceleration due to gravity.

[0014] The acceleration sensor according to the invention can be mounted anywhere on the moving actuator. It itself has no moving mechanical parts that require protection against environmental influences, making it extremely robust and easy to install. This represents a significant advantage over other sensor designs, which must be mounted at the center of the actuator's rotational axis, which is very difficult for retrofitting, especially in freight car braking systems.

[0015] It is possible that the position of the rotation axis relative to the earth's surface changes due to operational reasons (e.g., due to a temporary tilt of the vehicle, a gradient, or a lateral inclination of the track, particularly a track). This change in position is inherently determined by the measuring acceleration sensor, but represents an unknown measurement error from a measurement point of view. According to the invention, this change in position is therefore determined using the reference acceleration sensor. The values ​​of the measuring acceleration sensor must therefore be offset against the values ​​of the reference acceleration sensor to compensate for the measurement error.

[0016] The choice of mounting location for the reference acceleration sensor is free, as long as the mounting location on the vehicle is such that the reference acceleration sensor follows all movements of the vehicle as a whole. In other words, no relative movement may occur between the vehicle and the reference acceleration sensor. Thus, the reference acceleration sensor must be fixedly attached to the vehicle. In contrast, the measuring acceleration sensor is movably attached to the vehicle, as it is located on the actuating element, which is rotationally movable on the vehicle, and therefore follows its movements. The measuring acceleration sensor is fixedly attached to the actuating element itself, at least with regard to the rotation to be measured, i.e. with regard to the degrees of freedom associated with the rotation to be measured.

[0017] The following advantages can be achieved with the construction described above. The mounting location of the measurement acceleration sensor on the actuator can be chosen completely freely and without restrictions on mechanical connections. The mounting location of the reference acceleration sensor for determining the position of the rotation axis can be chosen completely freely and without restrictions on mechanical connections, as long as its position changes with the position of the vehicle. Due to the freedom in the mounting positions, no changes to any existing structures are necessary, and the measuring arrangement according to the invention can therefore be easily retrofitted. Due to the freedom in the mounting positions, a cost-optimized mounting method can be selected for both sensors independently of each other.

[0018] According to one embodiment of the invention, it is provided that the measuring acceleration sensor and the reference acceleration sensor are designed as three-axis sensors.

[0019] The use of a three-axis sensor for the reference acceleration sensor and the measurement acceleration sensor has the advantage that rotational position changes in three-dimensional space can be measured regardless of which of the three axes of the Cartesian coordinate system the rotation actually occurs around. This advantageously enables particularly precise measurements. In particular, a lateral inclination of the vehicle as well as a gradient or slope of the surface on which the vehicle is located can be taken into account.

[0020] Minimal tilting perpendicular to the direction of rotation of the rotation axis has no significant impact on the angle measurement, since the sine component of the angle change is small at small angles, and the resulting measurement error can therefore be neglected. Therefore, a 2-axis sensor can also be used for small inclination angles, in which case the tilting is ignored.

[0021] With a rotation axis perpendicular to the direction of travel, the tipping is a lateral inclination of the vehicle (e.g., cornering). With a rotation axis in the direction of travel, the tipping is an inclination in the direction of travel (e.g., uphill or downhill).

[0022] According to one embodiment of the invention, it is provided that the rotationally mounted actuating element forms part of a brake linkage for the vehicle.

[0023] The part of the brake linkage that forms the actuating element can be a (rotatably mounted) shaft or a rotatably mounted lever. Pure push or pull rods, however, are not suitable, as these are moved in a translational manner.

[0024] Before a freight train departs, it can be ensured that the braking system of a vehicle (freight wagon) is functioning correctly. This includes ensuring, among other things, that all brake pads on a bogie or freight wagon are present and still have sufficient pad thickness.

[0025] With the sensor arrangement according to the invention, it is possible to check, on block-braked vehicles, whether all pads are still present, whether the thickness of the brake pads used is still sufficient, and whether the brakes are released or actually applied, based on the angle change of only one component of the brake linkage on the vehicle (more on this in connection with the method according to the invention).

[0026] This advantageously means that sensor-based monitoring of the brake pads is possible with minimal metrological effort. Furthermore, the vehicle according to the invention can also be implemented by retrofitting the sensor arrangement according to the invention, since the measurement acceleration sensor and the reference acceleration sensor can be attached to the surface of components of the vehicle without the relevant (possibly approval-relevant) components themselves having to be modified in their function or design. According to one embodiment of the invention, the rotational axis of the rotary actuating element is installed in the vehicle at least substantially horizontally in the installed position.

[0027] An at least substantially horizontal installation position is also given if the installation position is not exactly horizontal, preferably inclined by up to 10° from the horizontal.

[0028] With a horizontally aligned rotation axis, the change in acceleration values ​​measured due to the rotation is fully incorporated into the angle calculation, which advantageously simplifies the calculation process, as shown below. At the same time, any measurement errors that may occur are advantageously reduced.

[0029] In a global coordinate system, the actuator's rotation axis lies on the y-axis, and the acceleration due to gravity acts along the z-axis. To calculate the angle of inclination to the Earth's surface in this simple case using the acceleration sensor, simplifying assumptions can be made. The sensor is rotated by an angle α around the y-axis, which changes the acceleration in the x- or z-direction. The following applies: A z = g ⋅ cos α und − A x = g ⋅ sin α and thus: α = arctan − A x / A z where A z and A x are the respective acceleration components in the z-direction and x-direction.

[0030] According to one embodiment of the invention, it is provided that the vehicle has an output device, which is configured to receive a result linked to the measurement of the setting angle via an output interface.

[0031] The output device advantageously enables a statement associated with the measurement of the setting angle, which may include, for example, the need for brake maintenance, to be displayed directly on the vehicle. This advantageously simplifies the assessment of required maintenance measures in the operation of a freight wagon, for example. For example, train crew can use the output device to determine whether the brakes functioned properly during the last journey or whether they require more detailed inspection to assess necessary maintenance measures. In particular, when dispatching a train, crew can determine whether the brakes are functioning properly even before it sets off. If this information is made available to the train driver live via an electronic device (e.g., a brake monitoring system), it helps to shorten the dispatch time of a train.

[0032] In the simplest case, the output device can be a warning light indicating the need for maintenance. The output device can also be a display that can transmit symbols or text information, such as "Maintenance required." It is also possible for the output device to emit a radio signal, which is received, for example, by a control center to assess the need for maintenance.

[0033] According to one embodiment of the invention, it is provided that the reference acceleration sensor and the output device are designed as a structural unit.

[0034] A sensor arrangement in which the reference acceleration sensor and the output device are designed as a single unit advantageously enables easier installation on the vehicle. The unit must be mounted in such a way that the output device is easy to operate and read for railway personnel. At the same time, the installation location must allow for a fixed connection of the unit so that the acceleration sensor can fulfill its function.

[0035] In contrast, the measuring acceleration sensor is attached to the actuator, which is normally less suitable for accommodating a display or output device due to limited accessibility.

[0036] The stated object is alternatively also achieved according to the invention with the subject matter of the claim (method) specified at the outset in that angle measurement data dependent on the setting angle and the vehicle position are generated by the sensor arrangement taking into account the direction of the acceleration due to gravity and measurement error measurement data dependent on the vehicle position are generated taking into account the direction of the acceleration due to gravity, and the setting angle is calculated from the angle measurement data with the aid of a computer, taking into account the measurement error measurement data.

[0037] The advantages associated with carrying out the method for determining an actuating angle of a rotationally moved actuating element have already been explained above in connection with the vehicle according to the invention and apply accordingly to the method according to the invention.

[0038] For the method according to the invention, the fact that the acceleration due to gravity is always aligned perpendicular to the center of the earth and thus represents a reliable reference as a vector for determining an adjustment angle, provided that the angle legs do not lie exactly in a horizontal plane (ie the axis of rotation of an adjustment element that realizes the adjustment angle is aligned vertically) is used.

[0039] The angle measurement data are thus generated relative to the vertical direction of the acceleration due to gravity, whereby the measurement method must be suitable for determining the setting angle relative to this reference.

[0040] In the context of the invention, "computer-aided" or "computer-implemented" can be understood as an implementation of the method in which at least one computer or processor carries out at least one method step of the method.

[0041] The term "computer" or "computer" covers all electronic devices with data processing capabilities. Computers can include, for example, personal computers, servers, handheld computers, mobile devices, and other communication devices that process data in a computerized manner, as well as processors and other electronic devices for data processing, which can preferably also be connected to form a network.

[0042] In the context of the invention, a "processor" can be understood as, for example, a converter, a sensor for generating measurement signals, or an electronic circuit. A processor can be, in particular, a central processing unit (CPU), a microprocessor, a microcontroller, or a digital signal processor, possibly in combination with a memory unit for storing program instructions, etc. A processor can also be understood as a virtualized processor or a soft CPU.

[0043] In the context of the invention, a "storage unit" can be understood as meaning, for example, a computer-readable memory in the form of a random-access memory (RAM) or data storage device (hard disk or data carrier).

[0044] "Interfaces" can be implemented in hardware, for example, via a wired or wireless connection, and / or in software, for example, as interaction between individual program modules or program parts of one or more computer programs.

[0045] "Program modules" are understood to mean individual functional units that enable a program sequence of method steps according to the invention. These functional units can be implemented in a single computer program or in several communicating computer programs. The interfaces implemented in this way can be implemented in software within a single processor or in hardware if multiple processors are used.

[0046] According to one embodiment of the invention, it is provided that the angle measurement data are generated with a measurement acceleration sensor which is fastened to the actuating element, and the measurement error measurement data are generated with a reference acceleration sensor which is fixedly fastened to the vehicle.

[0047] The use of acceleration sensors (measurement accelerometer and reference accelerometer) has the advantage that, due to their measuring principle, they directly utilize the acceleration due to gravity. Compared to other sensors, such as gyroscopes, which must be calibrated with respect to the direction of gravity, this makes the measurement process simpler to use and more reliable with regard to the occurrence of measurement errors.

[0048] According to the invention, it is provided that at least one stop value for the actuating element is calculated as the actuating angle, which stop value is measured when an increase in the actuating angle is prevented by a stop.

[0049] Vehicles have a multitude of rotary-mounted actuators whose positions are limited by at least one stop. Applying the method according to the invention to these actuators makes it possible to monitor their function. This can be used, for example, to check whether the intended adjustment angle is reached or maintained at the stop.

[0050] According to one embodiment of the invention, it is provided that a brake stop value is calculated as the stop value, which is formed in the event of a stop by a frictional connection between the friction partners of a brake, and / or a release stop value is calculated, which is formed in the event of a stop in the brake mechanism in the released state of the brake.

[0051] The application of the method to brakes requires that the brakes are adjusted using at least one rotary actuating element. The stop that needs to be monitored for such brakes is the contact of the brake pad with the other friction partner of the brake. In most freight wagons on the market, for example, the power is transmitted from the actuator (e.g. brake cylinder) to the brake via a brake linkage that has at least one rotatable shaft and / or a pivoting bellcrank. In freight wagons, the power is transmitted, for example, via a drawbar in the wagon body that pulls on a bellcrank attached to the wheelset. Via the bellcrank and another linkage, the tractive force is distributed to all brake blocks of a bogie or wagon chassis, resulting in the brake blocks pressing evenly onto the wheel tires.

[0052] The angle change of the lever or shaft is directly related to the total distance traveled by the brake pads between the released and applied positions during braking. The more worn the brake pads are, the greater the angle change compared to the new condition of the brake pads when applied, i.e., at the stop (more on this below).

[0053] According to one embodiment of the invention, it is provided that the brake stop value is stored as a calibration value for the brake stop and / or the release stop value is stored as a calibration value for the release stop.

[0054] The calibration process step is particularly advantageous when the brake pads have just been replaced and no measured values ​​for the serviced (or even new) brake system are yet available. The stop values, which are then calculated from the corresponding measured values ​​by activating or deactivating the brake as the brake stop value and the release stop value, then form a reference for the new condition of the brake pads, which can be stored in the memory device.

[0055] However, a calibration step can also be performed during the service life of brake pads. For example, brake pad wear can be precisely measured during regular maintenance, and new calibration values ​​can then be created for the measured condition of the brake pads.

[0056] According to one embodiment of the invention, it is provided that the brake stop value is compared with a limit value in a computer-aided manner and an output is given as to whether the stop value falls below and / or reaches and / or exceeds the limit value.

[0057] If the design-related relationship between the change in angle of brand-new brake pads and the residual pad thickness to be detected is known, the pad thickness of the brake pads can be determined from the angular position of the lever and an angle can be assigned to the wear limit to be detected.

[0058] As the pads wear, the angle increases until the stop, and thus the stop value with the brake applied, slowly but steadily increasing between the new condition and the wear limit, until it reaches the predefined limit. However, the angle change between two braking operations hardly differs. Over time, however, during normal operation, the limit is reached and subsequently exceeded.

[0059] When this angle is reached, the information can either be sent electronically to the employee responsible for maintenance or visualized to the vehicle inspector using a display device attached to the vehicle (e.g. the display of a brake monitoring system).

[0060] According to one embodiment of the invention, a computer-aided measurement series of brake stop values ​​and / or a measurement series of release stop values ​​is created, and the last calculated brake stop value and / or release stop value is compared with at least one previous brake stop value and / or release stop value in the measurement series. Of course, brake stop values ​​are always compared with other brake stop shafts in the respective measurement series, and release stop values ​​are always compared with other release stop values ​​in the respective measurement series.

[0061] Since the wear of the brake pads between braking applications is in the micrometer range, under normal circumstances, no change in the angle can be measured between braking applications. However, creating a series of measurements makes it possible to track the development. This allows, for example, predictions about the progression of wear and upcoming maintenance measures such as replacing the brake pads.

[0062] According to one embodiment of the invention, it is provided that the difference between the last calculated brake stop value and a brake stop value of the measurement series prior to this brake stop value is calculated and an output is made as to whether this difference falls below and / or reaches and / or exceeds a maximum permissible difference.

[0063] The maximum permissible difference is determined from empirical values ​​for a specific brake type such that it lies above a value applicable to normal wear of the brake pads. This means that a brake stop value exceeding this maximum permissible difference was measured due to an extraordinary event. Assuming that the measuring method is functioning correctly, exceeding the maximum permissible difference therefore indicates the loss of at least one brake pad. This loss is compensated for in the brake linkage by adjusting the relevant actuating element to a larger angle until all brake pads and at least one holder for the missing brake pad have reached the brake stop.

[0064] If at least one of the brake pads is lost, the distance the linkage has to travel during braking increases dramatically. This increase in distance also results in a sudden and measurable change in the setting angle. This can be determined by a simple comparison with the last calculated stop value in the series of measurements.

[0065] Since a lost brake pad cannot be replaced during a trip, it is usually sufficient to perform the measurement before starting or after the trip and save the measured value. The comparison is then always made between the current value and the stored value (for this application, therefore, considering a series of measurements with two stop values, the current and the previous one, is sufficient).

[0066] According to one embodiment of the invention, the measurement of the setting angle is carried out when the vehicle is stationary.

[0067] In principle, it is also possible to measure the setting angle while driving. Any accelerations that occur are eliminated by the reference acceleration sensor (or by the measurement result generated by it). However, the measurement errors that occur and need to be eliminated can be advantageously minimized if the measurement is taken while the vehicle is stationary. Therefore, more accurate measurement results can be obtained while stationary.

[0068] A further advantage is that, while the vehicle is stationary during the measurement process, the brakes can be (briefly) activated and deactivated to generate the measured values. This makes it possible to determine both a braking stop value and a release stop value in quick succession.

[0069] The above-mentioned object is alternatively achieved according to the invention with the subject matter of the claim specified at the outset (measuring arrangement) in that the measuring arrangement comprises: a measuring acceleration sensor for generating measurement data dependent on an actuating angle of an actuating element and on a vehicle position, a reference acceleration sensor for generating measurement data dependent on a vehicle position, an output device, a computer, a first interface between the measuring acceleration sensor and the computer, a second interface between the reference acceleration sensor and the computer, and an output interface between the output device and the computer.

[0070] The measuring system can be installed in a vehicle described above to implement the method described above. The measuring system is particularly suitable for retrofitting into an existing braking system of a freight car. The measuring system represents an independent functional system because it also includes a computer for calculating the setting angle from the measured values ​​(from the measurement acceleration sensor and the reference acceleration sensor).

[0071] Furthermore, a computer program product with program instructions for carrying out the said method according to the invention and / or its embodiments is claimed, wherein the method according to the invention and / or its embodiments can be carried out by means of the computer program product.

[0072] Furthermore, a provision device for storing and / or providing the computer program product is claimed. The provision device is, for example, a storage unit that stores and / or provides the computer program product. Alternatively and / or additionally, the provision device is, for example, a network service, a computer system, a server system, in particular a distributed, for example, cloud-based computer system and / or virtual computer system, which stores and / or provides the computer program product, preferably in the form of a data stream.

[0073] The provision takes place in the form of a program data block as a file, in particular as a download file, or as a data stream, in particular as a download data stream, of the computer program product. However, this provision can also take place, for example, as a partial download consisting of multiple parts. Such a computer program product is, for example, read into a system using the provision device, so that the method according to the invention is executed on a computer.

[0074] Further details of the invention are described below with reference to the drawings. Identical or corresponding elements of the drawings are provided with the same reference numerals and are explained several times only to the extent that differences arise between the individual figures.

[0075] The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments each represent individual, independently considered features of the invention, which also further develop the invention independently of one another and are thus also to be considered as components of the invention, either individually or in a combination other than that shown. Furthermore, the described components can also be combined with the features of the invention described above.

[0076] They show: Figure 1 an embodiment of the vehicle according to the invention with its functional relationships schematically, Figure 2 an embodiment of a computer infrastructure of the measuring arrangement according to the invention, as it is also used in a vehicle according to Figure 1can be used as a block diagram, where the individual functional units contain program modules, each of which can run in one or more processors and the interfaces can accordingly be implemented in software or hardware, Figure 3 a diagram showing the change in the setting angle α as a function of individual measurements n, which result in series of measurements, Figure 4 and 5 Embodiments of the method according to the invention as flow diagrams, wherein the individual method steps can be implemented individually or in groups by program modules and wherein the functional units and interfaces according to Figure 3 are indicated as examples.

[0077] In Figure 1A vehicle FZ is depicted in the form of a freight wagon. This vehicle FZ has a bogie DG at the end shown, which supports the wheels RD on two axles. Also shown schematically is a brake linkage BRG, which transmits the movement of an actuator AKT to the brake pads BRB, whereby the brake pads BRB act directly on the wheel rims (not shown) of the wheels RD. The brake linkage BRG is shown schematically. It is a mechanical transmission for transmitting the actuating movement of the actuator AKT, for example a hydraulic cylinder, to the brake pads BRB. The transmission consists of push and pull rods ZSS, which at least primarily perform a translational movement, indicated in Figure 1by double arrows parallel to the rod alignment. There are also levers that can be pivoted about a pivot axis, indicated by curved double arrows perpendicular to the lever alignment. Pivot axes or joints are indicated by circles at the ends of the pull or push rods (ZSS) and the levers, or in their center. Furthermore, the axle mounting on the vehicle (FZ) is indicated by fixed bearings (FL), with the respective hatching indicating the rigid connection to the vehicle (FZ) (including the bogie).

[0078] One of the levers is the actuator STE, which is pivoted around the indicated fixed bearing FL and is moved by the pull or push rod ZSS coming from the actuator AKT. A measuring acceleration sensor MBS is rigidly attached to this actuator, so that it pivots back and forth with the actuator STE. There is also a reference acceleration sensor RBS, which is rigidly connected to the vehicle FZ, according to Figure 1connected to the bogie DG (which forms part of the vehicle FZ). The measuring acceleration sensor MBS and the reference acceleration sensor RBS communicate via radio interfaces (not shown in detail) with an output device AE, whereby the output device AE also contains a computer for evaluating the received measured values ​​(see also Figure 2 ) Alternatively, cable interfaces can be used (not shown).

[0079] In Figure 2 The interaction of the functional elements involved in the method according to the invention is shown schematically as a block diagram. In this case, the vehicle FZ is divided into a block symbolizing the vehicle FZ and a housing GH, which, in contrast to Figure 1accommodates both the reference acceleration sensor RBS and the output device AE and is rigidly connected to the vehicle FZ. In the vehicle FZ, the actuating element STE is shown as an example, which rotates around a rotation axis DA (corresponds to the marked fixed bearing FL according to Figure 1 ) is rotatably mounted. The MBS measurement acceleration sensor is rigidly connected to the STE actuator.

[0080] In contrast to the Figure 1 In the variant shown, the output device AE and the reference acceleration sensor RBS are housed in a common housing GH. This advantageously simplifies installation, with the reference acceleration sensor RBS automatically being permanently connected to the vehicle FZ.

[0081] The measuring acceleration sensor MBS is connected to a computer CP via a first interface S1, and the reference acceleration sensor RBS is connected to a computer CP via a second interface S2, which evaluates the measurement results. Furthermore, the computer CP is connected to a storage device SE via a third interface S3. Calculated setting angles can be stored in the storage device SE in the form of a series of measurements, as well as calibration values ​​for commissioning the brakes and limit values ​​for their wear. The computer CP is connected to the output device AE via an output interface AS. The output device AE is preferably a display that can show information regarding the operation of the brake, or a system with, for example, a radio interface that can transmit the information directly to a central location, e.g., the locomotive (not shown).In the simplest case, the output device AE can be designed by (at least) one light which, without any further information, only indicates the need for maintenance (flashing when the brake pads BRB are worn beyond the wear limit, loss of brake pads / brake pads) and the current state of the brake (lighting corresponds to applied / not lit corresponds to released).

[0082] In Figure 2A setting angle α is defined as the deviation of the alignment of the actuating element STE (indicated by its dash-dotted axis of symmetry) from the vertical in which the acceleration due to gravity g acts (indicated by a downward-pointing arrow). This is an advantageous variant for the method of calculating angles from acceleration values, as the calculated angle then corresponds exactly to the setting angle α. In principle, the setting angle α can also be calculated from any other position of the actuating element STE. For example, the position of a calibrated position of the actuating element at the release stop, i.e. when the brake is released, or at the brake stop, i.e. when the brake is applied, can be set to zero.

[0083] If the entire vehicle FZ is tilted relative to the gravitational acceleration g (not shown), the angle α also contains a component due to the inclination of the vehicle FZ. This must then be calculated by subtracting the angle value measured by the reference acceleration sensor from the angle value measured by the measuring acceleration sensor to obtain the setting angle.

[0084] In Figure 3 is shown how the setting angle α (measured as Figure 2described) changes over the course of individual measurements n due to the wear of the brake pads. This makes it clear that measurements are only carried out at discrete points in time, for example before the vehicle is put into operation, resulting in a stepped progression. Shown are individual measurements for the brake stop value BAW n and individual measurements n for the release stop value LAW n . The release stop value LAW and the brake stop value BAW are each calculated from the measured accelerations of the measuring acceleration sensor MBS and the reference acceleration sensor RBS (cf. Figure 1 ) was determined.

[0085] At the first measurement according to Figure 3(n = 1) the brake pads are in new condition. This measurement calibrates the measuring arrangement according to the invention, whereby a calibration value CL for the release stop value LAW 1 and a calibration value CB for the brake stop value BAW 1 are calculated. These can be stored in the memory device SE (see Figure 2 ) can be stored.

[0086] In the following measurements, the setting angles α increase due to wear of the brake pads (brake stop values ​​BAW n ). The release stop values ​​LAW n can also change, as shown in Figure 3 This is shown when, depending on the brake pad wear, a mechanical adjustment of the release stop provided in the brake linkage when the brake is released is carried out (depending on the vehicle design). If such adjustment of the release stop does not occur, the release stop value LAW remains constant, so the calibration value for the release stop CL does not change.

[0087] For the development of the brake stop value BAW n, Figure 3 A limit value GW is drawn, indicating that the brake pads have reached their wear limit. The calibration value for the brake stop CB and the limit value GW define a drift range for the brake stop DBB. A drift range DBL for the release stop value is automatically generated by the mechanical adjustment of the release stop.

[0088] As already mentioned, the steps in the progression of the brake stop value BAW are caused by the wear of the brake pads, whereby between individual measurements n, n + 1, there is a wear-related difference between two brake stop values ​​ΔBAW. This is normally small and lies in the micrometer range. To avoid measurement inaccuracies, when creating a series of measurements (which are determined by the step progression according to Figure 3shown) can also be used for a measurement from further back, for example for a measurement n on the brake stop value BAW n-10.

[0089] In Figure 3 A jump in the brake stop value BAW is also shown when one brake block (KV1) is lost, or when two brake blocks (KV2) are lost. It is clear that the difference ΔBAW1 and the difference ΔBAW2 are significantly higher, as the brake linkage compensates for the loss, and the actuator (STE) thus suddenly achieves a larger actuation angle during braking. This detects the loss of brake blocks and can be output via the output device (AE).

[0090] The Figure 4The method sequence for the measuring method according to the invention can be seen as an example. After the method has been started, the available parameters are loaded from the storage device SE. In a query step, a check is made to see whether a limit value GW is already available. If not, the brake pads are new, which is why a calibration step CALIB is carried out. During calibration, the brakes are first released in a deactivation step UNLOCK. Then, in a measuring step ANGL of the measuring acceleration sensor, a setting angle measured value for the angular position of the actuating element is determined and in a measuring step REFC for the reference value by the reference acceleration sensor, a measurement error measured value is generated. In a subsequent calculation step CALC, the calibration value for the release stop CL is calculated and transferred to the storage device SE.

[0091] The calculation of the calibration value for the release stop CL as well as further release stop values ​​LAW and brake stop values ​​BAW (including the calibration value for the brake stop CB) are carried out in the embodiment according to Figure 4 by a sensor module SB, which also provides computing capacity for the calculation step CALC. However, this is only an example. It is also possible that the measurement steps for the angular position ANGL and the reference value REFC are transferred to the computer CP to perform the calculation step for the setting angle CALC. This represents the configuration, which according to Figure 2 described. For Figure 4 (and also for Figure 5 ) In this case, the system boundary indicated by a dot-dash line for the sensor module SB would be omitted without any other changes to the procedure.

[0092] The next step is a LOCK activation step for the brake, so that the brake pads are in contact with the brake stop. The measurement and calculation steps ANGL, REFC, CALC described above are repeated and provide the calibration value for the brake stop CB, which is transferred by the computer CP to the storage device SE.

[0093] In the following step, based on the calibration value for the brake stop CB and the knowledge of the conditions of the braking system, which can be stored in the memory device SE using formulas, the limit value GW can be calculated in a determination step for the limit value SET GW and transferred to the memory device SE by the computer CP.

[0094] If a limit value GW already exists, the calibration step CALIB can be skipped and a test step TEST is carried out to check the condition of the brake. For this purpose, an activation step of the brake LOCK is carried out, provided it is not yet applied. Subsequently, the calculation ANGL, REFC, CALC of the setting angle is carried out by the sensor module SB, as already explained above. The current brake stop value BAW n can then be transferred by the computer CP to the storage device SE. The computer CP then checks whether the current brake stop value BAW n falls below the limit value GW. For this purpose, the limit value GW is read from the storage device SE. In the event that the limit value GW is reached or exceeded, a maintenance signal is issued in an output step OUTPUT, which is sent directly to the output device AE according to Figure 2can be sent or stored as a maintenance signal MAINT in the storage device SE for later display.

[0095] If the brake stop value BAW n falls below the limit value GW, a further query is performed, for which the previously determined brake stop value BAW n-1 and the maximum permissible difference ΔMAX for a change in the brake stop value BAW are read from the memory device SE. If the calculated difference between the brake stop values ​​BAW n and BAW n-1 is smaller than the maximum permissible difference ΔMAX, the test is terminated and the process is stopped. If the said maximum is exceeded, this means that the brake has lost at least one brake pad, so that in the output step OUTPUT for the maintenance signal, an output is also made by the output device AE or the maintenance requirement MAINT is transferred by the computer CP to the memory device SE for later output. The process is also stopped after this.

[0096] In Figure 5shows another function that can be performed by the sensor arrangement according to the invention. This involves detecting the braking state, i.e. whether the brake pads are in the activated (applied) position or the deactivated (released) position. After the process has started, the measuring and calculation steps ANGL, REFC, CALC are carried out by the sensor module SB. This calculates the value W, which is then available for the further process. In a subsequent query, it is checked whether the value W approximately corresponds to the current brake stop value BAW n. If this is the case, an output step OUT LCK follows that the brake is activated, i.e. is in the braking position. Optionally, the value W can be transferred from the computer CP to the storage device SE as the new brake stop value BAW n+1. The process is then stopped.

[0097] If the value W does not approximately correspond to the brake stop value BAW n , a further query step checks whether the value W approximately corresponds to the current release stop value LAW n . If this is the case, an output step OUT UNL is performed, indicating that the brake is deactivated, i.e., open. Optionally, the value W can be transferred by the computer CP to the storage device SE as the current release stop value LAW n+1. The process is then stopped.

[0098] If the second query step also returns a negative result, i.e., there is no similarity between the value W and the current release stop value LAW n, the output step OUTPUT for a maintenance signal is initiated. Furthermore, the computer CP transmits a maintenance request MAINT to the storage device SE. The process is then stopped.

[0099] When considering whether the value W corresponds approximately to the brake stop value BAW n or the release stop value LAW n, measurement errors must be taken into account, which can be easily determined given the accuracy of the measurement method (therefore, an approximate agreement, i.e., within a confidence interval, is required). Furthermore, it must be taken into account that, as already mentioned, Figure 3 explained that, due to wear, a difference ΔBAW may occur between the determined brake stop values ​​between measurements. The same may also apply to the release stop value LAW. This change, referred to as drift, occurs in the drift ranges for the brake stop DBB and the release stop DBL (see Figure 3 ) must also be taken into account when setting the confidence interval for an approximate agreement of the value W. List of reference symbols

[0100] FZVehicle DGBogie RDWheel ACAxle FLFixed bearing ZSSPush-pull rod BRGBrake linkage AKTActuator BRBBrake pad STEActuator DARotary axis MBSMeasurement acceleration sensor RBSReference acceleration sensor GHGosealing AEInput device CPComputer SEStorage device SBSensor module ASOutput interface S1 ... S3Interface CALIB Calibration step UNLOCK Deactivation step for brake ANGLMeasurement step for angular position REFCMeasurement step for reference value CALCCalculation step for setting angle LOCK Activation step for brake SET GW Determination step for limit value TEST Test step OUTPUT Output of maintenance signal MAINT Maintenance requirement OUT LCK Output step for activated brake OUT UNL Output step for deactivated brake αSetting angle gAcceleration due to gravity nMeasurement CLCalibration value for the release stop CBCalibration value for the brake stop DBBDrift range of the brake stop DBLDrift range of the release stop BAWBrake stop value LAWLelease stop value ΔBAWDifference between two brake stop values ​​ΔMAXMaximum permissible difference GWLimit value KV1Pad loss (one brake pad) KV2Pad loss (two brake pads) WValue

Claims

1. Vehicle (FZ) with a rotationally movable actuating element (STE) and with a sensor arrangement for measuring an actuating angle (α) of the actuating element (STE), wherein the sensor arrangement • has a measuring acceleration sensor (MBS), which is fastened to the actuating element (STE), and • has a reference acceleration sensor (RBS), which is fastened immovably to the vehicle (FZ), wherein the sensor arrangement is configured • taking in account the direction of the acceleration due to gravity (g), to generate angle measurement data dependent on the actuating angle (α) and the vehicle position and • taking in account the direction of the acceleration due to gravity (g), to generate error measurement data dependent on the vehicle position, wherein the vehicle is configured for computer-aided calculation of the actuating angle (α) from the angle measurement data, taking into account the measurement error measurement data, characterised in that the vehicle is configured to calculate as actuating angle (α) at least one stop value for the actuating element (STE), which is measured when an increase in the actuating angle (α) is prevented by a stop.

2. Vehicle (FZ) according to claim 1 characterised in that the measuring acceleration sensor (MBS) and the reference acceleration sensor (RBS) are designed as three-axis sensors.

3. Vehicle (FZ) according to one of the preceding claims, characterised in that the rotationally supported actuating element (STE) forms a part of a brake linkage (BRG) for the vehicle (FZ).

4. Vehicle (FZ) according to one of the preceding claims, characterised in that the axis of rotation of the rotational actuating element (STE) in the vehicle (FZ) is installed at least essentially horizontally in its installation position.

5. Vehicle (FZ) according to one of the preceding claims, characterised in that the vehicle (FZ) has an output facility (AE), wherein said facility is configured to receive a result linked to the measurement of the actuating angle (α) via an output interface (AS) .

6. Vehicle (FZ) according to claim 5, characterised in that the reference acceleration sensor (RBS) and the output facility (AE) are designed as one structural unit.

7. Method for measuring the actuating angle (α) of a rotationally movable actuating element (STE) in a vehicle (FZ) in which a sensor arrangement for measuring the actuating angle (α) is employed, wherein by the sensor arrangement • taking account of the direction of the acceleration due to gravity (g), measurement data dependent on the actuating angle (α) and the vehicle position is generated and • taking account of the direction of the acceleration due to gravity (g), measurement error measurement data dependent on the vehicle position is generated, there is computer-aided calculation of the actuating angle (α) from the angle measurement data, taking into account the measurement error measurement data, characterised in that at least one stop value is calculated for the actuating element (STE) as the actuating angle (α), which is measured when an increase in the actuating angle (α) is prevented by a stop.

8. Method according to claim 7, characterised in that • the angle measurement data is generated with a measuring acceleration sensor (MBS), which is fastened to the actuating element (STE) and • the measurement error measurement data is generated with a reference acceleration sensor (RBS), which is fastened immovably to the vehicle (FZ).

9. Method according to claim 8, characterised in that, as stop values • a brake stop value (BAW) is calculated, which is formed by a frictional contact between the friction partners of a brake, and / or • a release stop value (LAW) is calculated, which is formed by a stop in the brake mechanism in the released state of the brake.

10. Method according to claim 9, characterised in that the brake stop value (BAW) is stored as a calibration value (CL) for the brake stop and / or the release stop value (LAW) is stored as a calibration value (CL) for the release stop.

11. Method according to claim 9 or 10, characterised in that there is a computer-aided comparison between the brake stop value (BAW) and a limit value (GW) and there is an output as to whether the stop value is less than the limit value (GW) and / or reaches and / or exceeds it.

12. Method according to one of claims 9 to 11, characterised in that there is computer-aided generation of a series of measurements of brake stop values (BAW) and / or a series of measurements of release stop values (LAW) and the last brake stop value (BAW) and / or release stop value (LAW) calculated is compared with at least one earlier brake stop value (BAW) and / or release stop value (LAW) of the series of measurements.

13. Method according to claim 12, characterised in that the difference between the last brake stop value (BAW) calculated and a brake stop value (BAW) of the series of measurements lying before this brake stop value (BAW) is calculated and there is an output as whether this difference is below a maximum allowed difference and / or reaches and / or exceeds it.

14. Method according to one of claims 7 to 13, characterised in that the measurement of the actuating angle (α) is made when the vehicle (FZ) is stationary.

15. Measurement arrangement, which is configured for carrying out a method for measurement, characterised in that said method has: a measuring acceleration sensor (MBS) for generation of measurement data dependent on an actuating angle (α) of an actuating element (STE) and a vehicle position, • a reference acceleration sensor (RBS) for generation of measurement data dependent on a vehicle position, • an output facility (AE), • a computer (CP), • a first interface (S1) between the measuring acceleration sensor (MBS) and the computer (CP), a second interface (S2) between the reference sensor (RBS) and the computer (CP) and an output interface (AS) between the output facility (AE) and the computer (CP).

16. Computer program product with program commands, which, when executed by a computer, lead to the method according to one of claims 7 - 14 being carried out.

17. Provision apparatus for the computer program product according to the last preceding claim, wherein the provision apparatus stores and / or provides the computer program product.