Method for checking a selector valve

Abstract

The present invention relates to a method for inspecting a shuttle valve (2) in a pneumatic system (100), wherein the shuttle valve (2) has a first shuttle valve interface (2.1), a second shuttle valve interface (2.2), and a third shuttle valve interface (2.3), wherein the higher of the pressures (p1, p2) applied at the first shuttle valve interface (2.1) and the second shuttle valve interface (2.2) is always regulated to the third shuttle valve interface (2.3), wherein the method comprises the following steps: a) regulating a first pressure (p1) to the first shuttle valve interface (2.1); b) obtaining an indication value (G1, G1T) at the first shuttle valve interface (2.1) for the first pressure (p1); and c) comparing the indication value (G1, G1T) for the first pressure (p1) with a predetermined first comparison value (GV1, GS1) set for this purpose, and if the deviation is greater than a first tolerance (T1): obtaining and / or outputting a fault (E) in the shuttle valve (2).

Description

Technical Field

[0001] This invention relates to a method for inspecting a shuttle valve in a pneumatic system, preferably an electronically controlled pneumatic braking system, wherein the shuttle valve has a first shuttle valve interface, a second shuttle valve interface, and a third shuttle valve interface, wherein the higher pressure of the pressure applied at the first and second shuttle valve interfaces is always regulated to the third shuttle valve interface. The invention also relates to a pneumatic system for a vehicle, preferably a commercial vehicle, having such a shuttle valve, and to a vehicle, preferably a commercial vehicle, having a pneumatic system of the aforementioned type. Background Technology

[0002] A shuttle valve that diverts the higher pressure applied to the first and second ports to the third port is also known as a "pressure selector valve." Such shuttle valves are used in a variety of ways in braking systems, for example, to couple redundant systems, divert redundant pressure, or perform other control tasks. Within the scope of redundant systems, shuttle valves are particularly suitable for use in higher levels of automation, especially at SAE levels 2–5, and especially 3–5. It is important to provide measures and methods for inspecting such shuttle valves, because in highly automated vehicles, human drivers can no longer identify faults without limitations.

[0003] In principle, it is possible to use additional, specialized sensors to check the functionality of such shuttle valves. However, this is costly, increases structural space and cost, and is hardly economical for widespread use. This is especially true when considering the typical use of multiple such shuttle valves in braking systems. Summary of the Invention

[0004] Therefore, the objective of this invention is to describe a method for inspecting such a shuttle valve, which allows for simple, inexpensive, and safe inspection of the shuttle valve even during vehicle operation.

[0005] In the first aspect, the present invention solves the task using a method of the type described at the beginning of this document, the method comprising the steps of: a) regulating a first pressure to a first shuttle valve interface; b) obtaining an indication value for the first pressure at the first shuttle valve interface; and c) comparing the indication value for the first pressure with a predetermined first comparison value set for this purpose, and if the deviation is greater than a first tolerance: knowing and / or that the output shuttle valve has malfunctioned.

[0006] The present invention is based on the idea of ​​ensuring the trouble-free operation of the height selection valve by comparing indicated values ​​of the pressure applied to the first shuttle valve interface during inflation and deflation. That is, during the regulation of a first pressure to the first shuttle valve interface, an indicated value for that pressure is obtained and then compared with a corresponding comparison value to check the functionality of the shuttle valve. This can be activated through extended testing, for example within the scope of extended departure control, or during continuous operation or active pressure regulation.

[0007] When a first pressure is applied to the first shuttle valve port in step a), it is preferable not to apply pressure to the second shuttle valve port, but rather to vent. However, there are also embodiments, which will be described later, in which pressure regulation is performed in parallel. When a first pressure is applied to the first shuttle valve port and ambient pressure is applied to the second shuttle valve port, the shuttle valve should respond such that a first pressure is provided at the third shuttle valve port. Typical faults that may occur in the shuttle valve include leakage, such as when the valve ball is stuck, or incorrect positioning of the valve element. Leakage may exist between the first and third shuttle valve ports, between the second and third shuttle valve ports, or even between the first and second shuttle valve ports. All these faults should be identified by the method described.

[0008] In principle, and preferably, to regulate first, second, and additional pressures at the first and second shuttle valve interfaces, these shuttle valve interfaces are vented from ambient pressure, vented from another pressure, or vented from a higher pressure to achieve the first, second, or additional pressure. For example, it is possible to first regulate to a maximum pressure during operation, and then vent from the maximum pressure to the corresponding first, second, or additional pressure in order to regulate the corresponding first, second, or additional pressure. It is also possible to provide the corresponding pressure at the first or second shuttle valve interface in this manner.

[0009] The indicated value for the first pressure can be, for example, a pressure measured in MPa over a specific duration, or a pressure change curve over a specific duration, for example, in MPa. The first time derivative of this value, i.e., the pressure gradient at a specific point in time, is particularly preferably a pressure gradient over a specific time period or a pressure gradient change curve over a specific duration. The gradient value is especially preferred because it illustrates how the first pressure changes over time, from which the switching and switching characteristics of the shuttle valve can be determined in a preferred manner.

[0010] After testing the first shuttle valve interface in steps a) to c), it is preferable to test the second shuttle valve interface in additional steps d) to f). For this purpose, it is preferable to apply a second pressure to the second shuttle valve interface in step d); obtain the indicated value for the second pressure at the second shuttle valve interface in step e); and compare the indicated value for the second pressure with a predetermined second comparison value in step f), and identify and / or output a fault if the deviation exceeds a second tolerance. During these steps, the first shuttle valve interface is preferably vented to ambient pressure. That is, after testing the first shuttle valve interface and before applying the second pressure to the second shuttle valve, the first shuttle valve interface is preferably vented to ambient pressure. The same discussion described above with reference to the first shuttle valve interface is substantially applicable to the inspection of the second shuttle valve interface, and therefore these discussions can be referenced.

[0011] In a preferred embodiment, the method includes the following steps: g) comparing the difference between the indicated value for a first pressure and the indicated value for a second pressure with a predetermined first threshold; and if the value is below the first threshold: identifying and / or outputting a shuttle valve malfunction. The shuttle valve should typically operate symmetrically, so that, given that the first or second pressure is preferably consistent, the difference between the corresponding indicated values ​​for the first and second pressures is also known. If the value is below the predetermined first threshold or the difference exceeds the proposed first threshold, then preferably, an malfunction is identified and / or output. The reason for exceeding or falling below the first threshold may be that the shuttle valve ball is stuck on one side, resulting in very different indicated values ​​for the first and second pressures.

[0012] The previous discussion preferably involved the so-called "sequential" regulation of the first and second pressures, where the first and second pressures were regulated sequentially, while the other shuttle valve port of the first and second shuttle valve ports was vented. However, in a preferred improvement, parallel regulation is performed. Preferably, in step d), as explained above, the second pressure is regulated to the second shuttle valve port while the first pressure has already been regulated to the first shuttle valve port. That is, in this case, the first pressure is first regulated to the first shuttle valve port and maintained, and then the second pressure is regulated to the second shuttle valve port after a predetermined period of time. For cases where the first and second pressures are at the same level and the shuttle valves are symmetrically constructed, the known indicated value for the first or second pressure should not change. When regulating the second pressure, even when the second pressure is at the same level, the first pressure is controlled to pass as always and the shuttle valve does not switch. Deviation from the expected indicated value for the first or second pressure can indicate a defect in the shuttle valve, thereby revealing and / or outputting a fault.

[0013] The indicated value for the first pressure is preferably a pressure gradient. A predetermined first comparison value in this case is a first comparative pressure gradient. The indicated value for the second pressure is also preferably a pressure gradient, i.e., a second pressure gradient. A predetermined second comparison value in this case is a second comparative pressure gradient. Preferably, multiple pressure gradients can also be detected separately within a specific time period, thus obtaining pressure gradient change curves. Therefore, in a preferred embodiment, the indicated value for the first pressure is a pressure gradient change curve, and the predetermined first comparison value is a first rated change curve. The indicated value for the second pressure is also preferably a pressure gradient change curve, and the predetermined second comparison value is a second rated change curve. The same discussion can also be applied to third, fourth, and other pressures and the corresponding indicated values ​​for these pressures.

[0014] The rated variation curve then involves the change of the pressure gradient over time, preferably starting from the point where a first pressure is regulated at the first shuttle valve interface. If this deviation exceeds a predetermined first tolerance, a fault is detected or output. The fault can preferably be output to the driver, or it can be output internally in the control unit only, in order to move the vehicle to a safe state.

[0015] The first and second pressures, or other pressures, can in principle be at different levels. Preferably, the method includes the following steps: adjusting a third pressure, less than the maximum pressure, to the second shuttle valve interface; adjusting a fourth pressure, higher than the third pressure, to the first shuttle valve interface; obtaining a pressure gradient change curve over time at the first shuttle valve interface; and obtaining the deviation of the obtained pressure gradient change curve from a predetermined rated change curve; and, upon confirmation of a deviation: identifying and / or outputting a shuttle valve malfunction. When the third pressure is first adjusted, the first shuttle valve interface is vented, and then the fourth pressure is adjusted, while the third pressure is still adjusted, the shuttle valve should be reversed, connecting the first and third shuttle valve interfaces. This is because the fourth pressure is higher than the third pressure. The fourth pressure can also substantially correspond to the first pressure. When the fourth pressure exceeds the third pressure, the reversal of the shuttle valve yields a characteristic line corresponding to the rated change curve. When the shuttle valve malfunctions, the actually measured characteristic line deviates from the rated change curve, thus identifying and / or outputting a malfunction.

[0016] It should be understood that this aspect can also be discussed independently of the first aspect described. That is to say, there is no mandatory requirement to perform steps a) to f) first as described above; rather, it is preferable to first regulate the third pressure, then regulate the fourth pressure and thus obtain the characteristic line, which is then compared with the nominal characteristic line.

[0017] In another preferred embodiment, the method includes the following steps: regulating a fifth pressure to the first shuttle valve interface; regulating a sixth pressure to the second shuttle valve interface during the regulation of the fifth pressure, wherein the sixth pressure is a very small pressure; detecting the pressure applied to the second shuttle valve interface over a period of time; and, upon a rise in the pressure applied to the second shuttle valve interface: detecting and / or outputting a shuttle valve malfunction. It is also possible to regulate the sixth pressure first, followed immediately by the fifth pressure, or to regulate both pressures simultaneously. The sixth pressure is a very small pressure, preferably a minimum pressure, preferably the smallest pressure that the corresponding system can provide at the second shuttle valve interface. The pressure level is, for example, in the range of 0.01 MPa to 0.05 MPa. When detecting a rise in the pressure applied to the second shuttle valve interface, it is either in the form of a pressure value measured in MPa or a gradient measured in MPa / s, preferably using a threshold that takes into account a certain tolerance range. If the pressure at the second shuttle valve interface rises over a period of time, this may be an indication that air is overflowing from the first shuttle valve interface to the second shuttle valve interface. This should generally be prevented in the shuttle valve, and in the current implementation, the pressure of the first shuttle valve interface should only be provided at the third shuttle valve interface, without any pressure being regulated from the second shuttle valve interface to the first or third shuttle valve interface.

[0018] However, since it is conceivable in principle that the module regulating the sixth pressure at the second shuttle valve interface has a leak, and due to this leak, the pressure at the second shuttle valve interface rises for a period of time, the method preferably includes the following steps: venting the first shuttle valve interface from the fifth pressure to the ambient pressure, and regulating the second shuttle valve interface to the sixth pressure; detecting the pressure applied to the second shuttle valve interface for a period of time; and when the pressure applied to the second shuttle valve interface remains within a predetermined tolerance: identifying and / or outputting a shuttle valve malfunction. These steps are performed immediately following the steps described above. When the pressure at the second shuttle valve interface rises during the regulation of the fifth pressure, but does not rise when no pressure is regulated at the first shuttle valve interface, this indicates that it is not the module connected to the second shuttle valve interface that is leaking, but rather that air is overflowing from the first shuttle valve interface to the second shuttle valve interface. It is precisely in this case that a malfunction should be identified or output. Pressure can also be known as a pressure value or pressure change curve measured in units such as MPa, or as the time derivative of the pressure, i.e., as a pressure gradient or pressure gradient change curve measured in units such as MPa / s.

[0019] In a preferred improvement, the method further includes the following steps: obtaining the current reservoir pressure; wherein, at least step c) above is performed, taking into account the obtained current reservoir pressure. Depending on the level of the reservoir pressure, the gradient or gradient change curve may present differently, thus it is preferable to take into account the reservoir pressure. The same description also applies to step f) above. Higher reservoir pressure may result in a proportionally higher pressure gradient, thus by taking into account the reservoir pressure, the obtained pressure gradient and pressure gradient change curve can be standardized.

[0020] The predetermined comparison value for comparing with the indicated value for the first pressure is preferably a value learned from previously measured values. During normal vehicle operation, the indicated values ​​for the first pressure and other values, such as the indicated values ​​for the second pressure, are detected and stored. These values ​​are referred to as learned values. If a deviation from these values ​​is confirmed, it indicates a defect in the shuttle valve. This applies to all indicated values ​​for pressure, particularly individual pressure values, pressure variation curves, gradients, and gradient variation curves.

[0021] Preferably, the first and second gradients at the first and second shuttle valve interfaces, as well as the first and second gradient change curves, are compared with each other to identify faults in this manner. In another preferred embodiment, a predetermined first comparison value is received at least from internal storage media and / or wirelessly from a cloud service. The same description preferably applies to other values, such as a predetermined second comparison value, a predetermined first threshold, and a predetermined rated change curve, as well as other comparison values ​​for the first and second gradient change curves and other values ​​used therein. On the one hand, it is conceivable that the manufacturer pre-stores these values ​​in internal memory and updates them as needed during service. On the other hand, it is also conceivable and preferred that these values ​​be provided via a cloud service. This allows for updating on a server and, accordingly, providing these values ​​via a cloud service. Here, other characteristics, such as lifespan and runtime, can also be considered.

[0022] To connect to cloud services, a corresponding interface is preferably provided, which is capable of wirelessly receiving one or more corresponding values. Therefore, a vehicle implementing the aforementioned method can include a radio module, such as an LTE module.

[0023] In another preferred embodiment, a first valve module, preferably a first axle modulator, is connected to a first shuttle valve interface, and a second valve module, preferably a second axle modulator, is connected to a second shuttle valve interface. The first and second valve modules communicate electronically with each other indirectly or directly, and a third shuttle valve interface is connected to a consumer, preferably a brake actuator. The first axle modulator is preferably configured for normal vehicle operation, and the second axle modulator is configured for redundant vehicle operation. The indirect or direct communication between the first and second axle modulators is then used to transmit both operating signals and stop signals, fault signals, etc. Indirect communication can be accomplished, for example, through an intermediate connected module, vehicle bus, etc. It is in these cases that the shuttle valve's operational capability becomes crucial if, in redundant operation, the second axle modulator must take over the task of safely braking the vehicle.

[0024] Preferably, the steps of the method are performed during vehicle braking, wherein the first pressure is a first braking pressure used to brake the vehicle. When providing the first braking pressure for braking the vehicle, it is always preferable to test the shuttle valve's operational capability after the preceding steps. In this case, it is not necessary to implement or execute separate test routines for the vehicle, thus enabling an effective testing process overall.

[0025] Preferably, the method is implemented when the vehicle is stopped, wherein the method further includes the steps of: receiving a departure control signal to implement departure control; and, in response to receiving the departure control signal, performing at least steps a) to c). According to this embodiment, the method, at least steps a) to c), and preferably additional steps are performed within the scope of extended departure control for the vehicle. This improves overall vehicle safety.

[0026] In a second aspect, the invention solves the task described at the beginning of this document using a pneumatic system of the type described at the beginning of this document, wherein, in addition to the shuttle valve described at the beginning of this document, it further includes a first valve module connected to a first shuttle valve interface to regulate a first pressure to the first shuttle valve interface and includes a first pressure sensor for detecting an indication value for the first pressure; and also includes a second valve module connected to a second shuttle valve interface to regulate a second pressure to the second shuttle valve interface and having a second pressure sensor for detecting an indication value for the second pressure; and further includes an electronic control unit connected to the first and second valve units for receiving first and second pressure signals from the first and second pressure sensors, the first and second pressure signals representing the first and second indication values, wherein the electronic control unit also has means suitable for implementing the steps of the method according to the first aspect of the invention.

[0027] It should be understood that the method according to the first aspect of the invention and the pneumatic system according to the second aspect of the invention have the same and similar sub-aspects, as particularly as written in the dependent claims. In this regard, reference can be made fully to the foregoing description of the first aspect of the invention for particular embodiments and their advantages and combinations of features.

[0028] The pneumatic system is preferably part of an electronically controlled braking system for commercial vehicles, especially those with higher levels of automation, particularly those classified as SAE Level 3, 4, or 5. Devices suitable for implementing the steps of the method according to the first aspect of the invention preferably include a processor and a memory storing software code.

[0029] In a first preferred embodiment of the pneumatic system, the first valve unit is configured as a first axle modulator, and the second valve unit is configured as a second axle modulator, wherein the third shuttle valve interface is connected to the brake actuator in a fluid-guiding manner.

[0030] Furthermore, it is preferable that the first axle modulator is constructed and configured for normal vehicle operation, and the second axle modulator is constructed and configured for redundancy, in which the first axle modulator is unable to operate or cannot operate correctly. The cause of the first axle modulator's failure may be a failure of the upstream system or a direct fault within the first axle modulator itself.

[0031] Preferably, no additional pressure sensor is present in the path downstream of the third shuttle valve interface. The third shuttle valve interface is preferably connected to the brake actuator directly or via a short hose or fitting. The inspection according to the method of the first aspect of the invention is preferably carried out using only the sensors in the first and second valve units. Specifically, the pressure applied at the first shuttle valve interface is detected by a first pressure sensor and the pressure applied at the second shuttle valve interface is detected by a second pressure sensor. This allows the determination of corresponding indication values ​​for the first or second pressure, such as pressure gradients or pressure gradient change curves. Additional sensors are not necessary and can be omitted within the scope of the invention.

[0032] In the third aspect, the task mentioned at the beginning of this document is solved by a vehicle, preferably a commercial vehicle, having a pneumatic system according to a second aspect of the invention, as described in one of the preferred embodiments of the previously described pneumatic system.

[0033] In the fourth aspect, the task mentioned at the beginning of this document is solved by a computer program comprising instructions that cause the pneumatic system according to the second aspect of the invention to perform the method steps of the method according to the first aspect of the invention in one of the aforementioned preferred embodiments of the method.

[0034] Embodiments of the invention will now be described below with the aid of the accompanying drawings. These drawings are not necessarily to scale; rather, the drawings used for illustration are presented in a schematic and / or slightly distorted form. For supplementary information regarding the teachings readily apparent from the drawings, refer to the relevant prior art. It should be considered that a variety of modifications and changes to the form and details relating to the embodiments are possible without departing from the overall spirit of the invention. The features of the invention disclosed in the specification, drawings, and claims, whether individually or in any combination, are of great importance to improvements of the invention. Furthermore, all combinations of at least two features disclosed in the specification, drawings, and / or claims fall within the scope of the invention. The overall spirit of the invention is not limited to the exact form or details of the preferred embodiments shown and described below, nor is it limited to the subject matter restricted compared to the claims. Values ​​within the limits of the established measurement range should also be disclosed as limit values ​​and can be used freely and protected by law. For simplicity, the same reference numerals are used below for consistent or similar parts or parts having consistent or similar functions. Attached Figure Description

[0035] Further advantages, features, and details of the present invention will become apparent from the following description of preferred embodiments and with reference to the accompanying drawings; wherein:

[0036] Figure 1 A pneumatic system according to a first embodiment is shown;

[0037] Figure 2 A pneumatic system according to a second embodiment is shown;

[0038] Figure 3 A vehicle with a braking system is shown;

[0039] Figure 4 A graph showing the pressure gradient is displayed;

[0040] Figure 5 A second graph with a pressure gradient is shown; and

[0041] Figure 6 The diagram illustrates a schematic flow of the method. Detailed Implementation

[0042] According to the first embodiment, the pneumatic system 100 ( Figure 1 The device includes a shuttle valve 2, constructed according to conventional methods. Shuttle valve 2 has a first shuttle valve port 2.1, a second shuttle valve port 2.2, and a third shuttle valve port 2.3. The shuttle valve 2 is constructed such that the higher pressure applied to the first and second shuttle valve ports 2.1 and 2.2 is always directed to the third shuttle valve port 2.3. Shuttle valve 2 is therefore also referred to as a "high-pressure selector valve." Such high-pressure selector valves are widely used in electro-hydraulic braking systems and have become standard components.

[0043] according to Figure 1 In the illustrated embodiment, the first shuttle valve interface 2.1 is connected to the first valve module 4, and the second shuttle valve interface 2.2 is connected to the second valve module 6. The third shuttle valve interface 2.3 can be connected to a consumable, such as, in particular, a brake actuator 8 (see...). Figure 3 However, other consumables can also be connected to the third shuttle valve interface 2.3, such as (not shown) modulators, spring accumulators, brake cylinders, trailer control valves, and similar consumables.

[0044] The first and second valve modules 4 and 6 can be preferably configured as follows: Figure 2 The first and second axle modulators 10 and 12 are configured as shown in the second embodiment. This will be explained further in more detail.

[0045] The first valve module 4 is used to regulate at least a first pressure P1 to the first shuttle valve interface 2.1. Furthermore, the first valve module 4 is also capable of regulating an additional pressure to the first shuttle valve interface 2.1, as will be described more precisely below. To detect the pressure regulated to the first shuttle valve interface 2.1, the first valve module 4 includes a first pressure sensor 14, which provides a first pressure signal SP1. The second valve module 6 is uniformly configured to regulate at least a second pressure p2 to the second shuttle valve interface 2.2. Furthermore, the second valve module 6 is capable of regulating an additional pressure to the second shuttle valve interface 2.2, as will be described precisely below. The second valve module 6 includes a second pressure sensor 16, which is configured to detect the pressure regulated to the second shuttle valve interface 2.2 and provide a corresponding second pressure signal SP2.

[0046] In addition, by Figure 1It is understood that the first and second valve modules 4 communicate with each other. For this purpose, signal lines 20 are drawn between these valve modules. Signal lines 20 are hereby described for illustrative purposes only and should clarify that the first and second valve modules 4 and 6 can communicate with each other indirectly or directly. Signal lines 20 can be constructed, for example, by direct wiring between the first and second valve modules 4 and 6, i.e., by a vehicle bus, which also interconnects other modules not shown herein, or by indirect connections via other modules (also not shown). However, signal lines 20 can also be formed by multiple signal lines. The first and second pressure signals SP1 and SP2 are also preferably provided via signal lines 20.

[0047] In such Figure 2 In the first practical design shown, the first valve module 4 is formed by the first axle modulator 10 and the second valve module 6 is formed by the second axle modulator 12. The first axle modulator 10 in this embodiment ( Figure 2 It has its own intelligence in the form of a first electronic control unit ECU1. The second valve module 6, which is configured as a second axle modulator 12, also has its own intelligence in the form of a second electronic control unit ECU2.

[0048] In addition to the first electronic control unit ECU1 and the first pressure sensor 14, the first valve module 4 also has a first valve device 22, which is not described in detail here, but is used to receive the reservoir pressure pV from the reservoir interface 24 of the first valve module 4 and provide this reservoir pressure as, for example, a first pressure p1 to the first shuttle valve interface 2.1. This occurs depending on the switching of one or more switching valves within the first valve device 22. The structure of the axle modulator is known in principle, so its exact structure need not be discussed further here. The second valve module 6, configured here as the second axle modulator 12, is correspondingly constructed and has a second valve device 26, which receives the reservoir pressure pV via the second reservoir interface 28. Depending on the position of one or more switching valves in the second valve device 26, at least a second pressure p2 is regulated to the second shuttle valve interface 2.2. The reservoir pressure pV can be provided by one or more different compressed air reservoirs, as referenced. Figure 3 To elaborate further. Figure 2In the illustrated embodiment, the first pressure sensor 14 is connected to the first electronic control unit (ECU1) and provides a first pressure signal SP1 to the ECU. The ECU1 is then connected to signal line 20 and can provide the first pressure signal SP1 to another unit, such as, in particular, the second valve module 6, via this signal line. Alternatively, the ECU1 can provide a signal derived from the first pressure signal SP1 via signal line 20. The second pressure sensor 16 of the second valve module 6 is also connected to the second electronic control unit (ECU2) in a similar manner and provides a second pressure signal SP2 to the ECU. The second ECU2 is then itself connected to signal line 20 and can provide the second pressure signal SP2 to this signal line. Likewise, the ECU2 can provide a signal derived from the second pressure signal SP2 via signal line 20.

[0049] exist Figure 3 The diagram shows a pneumatic system 100 in the installation state within the braking system 102. Figure 3 More precisely, vehicle 200, or commercial vehicle 202, includes an electronically controlled pneumatic braking system 102 with the aforementioned pneumatic system 100. Vehicle 200 has a front axle VA and a rear axle HA, but may also include an additional rear axle. Braking system 102 has a rear axle braking circuit 204, a front axle braking circuit 206, and a parking brake circuit 208. The rear axle braking circuit 204 is supplied by a first compressed air reservoir 210, the front axle braking circuit 206 by a second compressed air reservoir 212, and the parking brake circuit 208 by a third compressed air reservoir 214. All three compressed air reservoirs 210, 212, and 214 provide a reservoir pressure pV.

[0050] For controlling the braking system 102, a central unit 220 is provided, which has a central electronic control unit (ECUZ). The central unit 220 is connected to a unit 224 for autonomous driving via a vehicle bus 222 to obtain control signals, braking request signals, or similar signals from the autonomous driving unit. The vehicle bus 222 also forms part of the signal line 20.

[0051] The braking system 102 includes a brake actuator 8 at the front axle VA, which is located at the right front wheel of the front axle VA. The braking system 102 includes an additional brake actuator 226 at the left front wheel of the front axle VA and rear axle brake actuators 228a and 228b at the rear axle HA. The braking system 102 also includes a front axle modulator 230 at the front axle VA, which is configured as either a first axle modulator 10 or a first valve module 4. The front axle modulator 230 is connected to and receives a switching signal from the central unit 220 via a front axle brake signal line 232. Furthermore, the front axle modulator 230 is connected to and receives a reservoir pressure pV from a second compressed air reservoir 212. The front axle modulator 230 is designed to regulate the front axle brake pressure pBVA based on the signal received via the front axle brake signal line 232, which is also part of the signal line 20. This is done in a manner known in principle. The front axle braking pressure pBVA is then supplied to the brake actuator 8 and the additional brake actuator 226 via the first and second ABS valves 234a and 234b to achieve braking adapted to the wheels.

[0052] A rear axle modulator 236 is provided at the rear axle HA in a similar manner. This rear axle modulator is connected to the first compressed air reservoir 210 and to the central unit 220 via the rear axle brake signal line 238. The rear axle modulator 236 regulates the rear axle brake pressure pBHA to the rear axle brake actuators 228a and 228b.

[0053] In response to a failure in the braking system 202, such as in the autonomous driving unit 224, the central unit 20, or the front axle modulator 230 and rear axle modulator 236, the braking system 202 includes a redundant control unit 240. This redundant control unit is also connected to the autonomous driving unit 224 via the vehicle bus 222 and to the central unit 220 via internal signal lines 242. The redundant central unit 240 is configured to take over control of the braking system 202 in the event of a failure.

[0054] In addition to the redundant central unit 240, the braking system 202 also includes a redundant front axle modulator 244, which is in the form of a second axle modulator 12 or a second valve module 6. The redundant front axle modulator 244 is also connected to the brake actuator 8 or another brake actuator 226 via redundant front axle ABS valves 246a, 246b. In case of failure, the redundant central unit 240 controls the redundant front axle modulator 244 to regulate the front axle braking pressure pBVA. For this purpose, the redundant front axle modulator 244 is also connected to the second compressed air reservoir 2 and to the redundant central unit 240 via a redundant front axle brake signal line 248. The redundant front axle brake signal line 248 also forms part of the signal line 20. The redundant front axle modulator 244 is connected to the front axle modulator 230 in this way via the redundant front axle brake signal line 248, the redundant central unit 40, the central unit 240, and the front axle brake signal line 232, so that it can exchange signals and communicate with the front axle modulator.

[0055] A shuttle valve 2 or another shuttle valve 250 is connected between the ABS valves 234a, 234b or the redundant front axle ABS valves 246a, 246b and the brake actuator 8 or another brake actuator 226. The following description focuses primarily on the shuttle valve 2; it should be understood that the shuttle valves 250 are identically constructed and operate in the same manner. More precisely, the right-hand ABS valve 234a is connected to the first shuttle valve interface 2.1, and the right-hand redundant front axle ABS valve 246a is connected to the second shuttle valve interface 2.2. The third shuttle valve interface 2.3 is directly connected to the brake chamber of the brake actuator 8.

[0056] A similar connection is provided for the other brake actuator 226. A redundant rear axle modulator 252 is provided for the rear axle brake circuit 204, which can replace the rear axle modulator 236 in case of failure. This redundant rear axle modulator is also connected to the rear axle brake actuators 228a and 228b via the first and second rear axle shuttle valves 254a and 254b, as has been substantially explained with reference to the front axle VA. Therefore, this connection will not be discussed in detail here.

[0057] Therefore, the braking system 102 has a total of four shuttle valves: shuttle valve 2, additional shuttle valve 250, and first and second rear axle shuttle valves 254a and 254b. In principle, these shuttle valves are used to divert the front axle braking pressure pBVA or the rear axle braking pressure pBHA to the corresponding brake actuators during normal operation. If, in the event of a failure, the redundant central unit 240 must take over, then the front axle braking pressure pBVA or the rear axle braking pressure pBHA is regulated via the redundant front axle modulator 244 or the redundant rear axle modulator 252, and thus supplied to the corresponding brake actuators via the corresponding shuttle valves. Therefore, the proper operation of all shuttle valves is crucial.

[0058] To inspect shuttle valves 2, 250, 254a, and 254b, it is preferable to perform the method for inspecting shuttle valves according to the invention when the vehicle 200 is stationary or during operation. Inspecting shuttle valve 2 can be performed both within the scope of extended vehicle departure control, before the vehicle 200 begins to move, and also during the operation of the vehicle 200, for example, when the front axle braking pressure pBVA and / or the rear axle braking pressure pBHA are regulated. Within the scope of the method, it is preferable to first perform the following steps: regulating a first pressure p1 to the first shuttle valve interface 2.1; obtaining an indication value for the first pressure p1 at the first shuttle valve interface 2.1; and comparing the indication value for the first pressure with a predetermined first comparison value set for this purpose. In one embodiment, the indication value for the first pressure is represented on the one hand as a first pressure gradient G1 at the first shuttle valve interface 2.1, but on the other hand, it is also represented as a pressure gradient change curve G1T at this location. After comparing the first pressure gradient G1 with a predetermined first comparison value GV1, or comparing the pressure gradient change curve G1T with the first rated change curve GS1 in the case of pressure gradient change curve G1T, if the deviation is greater than the first tolerance T1, the fault E of the output shuttle valve 2 is known and / or the fault E is detected.

[0059] Figure 6 The method flow is shown in the figure, while Figure 4 and Figure 5 Different indications for the first or second pressure are shown in the form of pressure gradients and pressure gradient variation curves, and are explained in detail below. It should be understood that other values, such as absolute pressure values ​​in particular, or pressure gradients over specific time intervals, can also be used as indications for pressure.

[0060] according to Figure 6 For example, the inspection method is first initialized in step St1. Then, in step St2, tolerance, rated variation curves, or other comparison values ​​can be retrieved, for example, from the memory M inside the central control unit 220 or the first or second electronic control unit ECU1, ECU2. Alternatively, these values ​​may be obtained via cloud service C. Then, in step St3, the first valve module 4 regulates the first pressure p1 to the first shuttle valve interface 2.1 (see...). Figures 1-3 When no pressure is regulated to the second shuttle valve interface 2.2 in this step, and instead an ambient pressure p0 is applied, the first pressure p1 regulated to the first shuttle valve interface 2.1 is provided to the third shuttle valve interface 2.3 via shuttle valve 2. Here, a characteristic first pressure gradient G1 and a first pressure gradient variation curve G1T are obtained. This is in... Figure 4 As shown in the image.

[0061] Figure 4The response of shuttle valve 2 is explained (regarding both the first pressure p1 and the second pressure p2). If the first pressure p1, shown here as a jump function, is applied to the first shuttle valve interface 2.1, then shuttle valve 2 functions and applies this pressure to the third shuttle valve interface 2.3. Figure 4 The diagram also shows the first rated variation curve GS1 for the first pressure gradient ratio variation curve G1T and the first comparison value GV1. Figure 4 It can be seen that both the first pressure gradient change curve GS1 and the first pressure gradient G1 are below the first rated change curve GS1 and the first comparison value GV1. However, both are still within the first tolerance T1, which is exemplarily drawn only at one part of the graph. As long as the first pressure gradient change curve G1T and / or the first pressure gradient G1 are within the first tolerance T1, fault E is not output. That is to say, in step St4, the first pressure gradient G1 or the first pressure gradient change curve G1T at the first shuttle valve interface 2.1 is first obtained, and then a comparison is performed in step St5 to determine whether the obtained value is within the tolerance T1. If the obtained value is within the tolerance T1, then the method is terminated in step St6. Then it can be restarted in step St1, for example, after a predetermined time, after the vehicle 200 is restarted, or after a similar time. However, if the obtained value is outside the first tolerance T1, then fault E is output. The fault E can be output either to a higher-level unit, such as unit 224 for autonomous driving, or also to the driver of vehicle 200 via a screen display.

[0062] However, it is also possible that after step St6, the shuttle valve 2 is further inspected, more specifically the second shuttle valve interface 2.2. When this is to be done, in step St7, a second pressure p2 is regulated to the second shuttle valve interface 2.2, while the first shuttle valve interface 2.1 is preferably vented, that is, the ambient pressure p0 is applied to the first shuttle valve interface 2.1. Then, in step St8, the second pressure gradient G2 or the second pressure gradient change curve G2T at the second shuttle valve interface 2.2 is obtained. Then, in step St9, the obtained second pressure gradient G2 or the second pressure gradient change curve G2T is compared with a predetermined second comparison value GV2 and / or a second rated change curve GS2. The predetermined second comparison value GV2 and the second rated change curve GS2 have preferably been retrieved from memory M or C in step St2. Then, in step St9, a comparison is performed again, and if the value of the second pressure gradient G2 or the second pressure gradient change curve G2T is within the second tolerance T2, either return to step St6 and terminate the method, or return to step St1 to restart the method directly or at a later time point. However, if it is confirmed in step St9 that the measured value is outside the second tolerance T2, then fault E is output. The second pressure gradient change curve G2T and the second pressure gradient G2 are within... Figure 4 It is drawn in the middle.

[0063] However, it is also possible that the pressure is not strictly controlled sequentially, that is, sequentially, to the first and second shuttle valve interfaces 2.1 and 2.2, but rather partially or completely in parallel. Figure 5 This illustration is shown in the image. According to... Figure 5 In the method for inspecting shuttle valve 2, a third pressure p3 is first applied to the second shuttle valve interface 2.2, where the third pressure p3 is less than the maximum pressure pMAX that the second valve module 6 can control. At this point, the first shuttle valve interface 2.1 is first vented and the ambient pressure p0 is applied. After the second shuttle valve interface 2.2 is vented with the third pressure p3, the first shuttle valve interface 2.1 is now vented with the fourth pressure p4 through the first valve module 4. Figure 5 In the illustrated embodiment, inflation is performed using the maximum pressure pMAX. With shuttle valve 2 operating correctly, the shuttle valve must now be redirected and no longer control the third pressure p3 from the second shuttle valve port 2.2 to the third shuttle valve port 2.3, but instead control the fourth pressure p4 from the first shuttle valve port 2.1 to the third shuttle valve port 2.3. Here, the fourth pressure gradient G4 and the fourth pressure gradient variation curve G4T are obtained. Figure 5The fourth rated variation curve GS4 and the fourth comparison value GV4 are also plotted. Here, it is also possible to check again whether the fourth pressure gradient variation curve G4T corresponds sufficiently to the fourth rated variation curve GS4, and whether the fourth pressure gradient G4 is within the tolerance range (not shown) for the fourth comparison value GV4.

[0064] Another method for inspecting shuttle valve 2 is as follows: First, adjust the fifth pressure p5 to the first shuttle valve interface 2.1 (see...). Figure 1 The fifth pressure p5 corresponds to the maximum pressure pMAX, or a slightly reduced pressure. A sixth pressure p6 is then, simultaneously with or beforehand, regulated to the second shuttle valve interface 2.2. This sixth pressure is preferably a very small pressure, especially the minimum pressure achievable by the second valve module 6, or the smallest possible pressure. The sixth pressure p6 is, for example, in the range of 0.01 to 0.05 MPa. The pressure applied to the second shuttle valve interface 2.2 is then detected over a period of time. This is achieved using the second pressure sensor 16. The detected pressure p6.2 is observed. If this detected pressure p6.2 rises over a period of time, it indicates a defect in the shuttle valve 2 and that the fifth pressure p5 overflows to the second shuttle valve interface 2.2. That is, if the gradient known in this way exceeds a threshold corresponding to that gradient, a fault is known and / or output. To verify this, the first shuttle valve interface 2.1 can then be vented to the ambient pressure p0 in a separate step, and the sixth pressure p6 can be regulated to the second shuttle valve interface 2.2. If the applied pressure p6.2 is observed and it does not rise, i.e., the corresponding gradient is approximately 0, it usually indicates that shuttle valve 2 is defective. In this case, a fault E in the output is known.

[0065] List of reference numerals

[0066] 2. Shuttle valve

[0067] 2.1 First shuttle valve interface

[0068] 2.2 Second shuttle valve interface

[0069] 2.3 Third shuttle valve interface

[0070] 4 First Valve Module

[0071] 6 Second Valve Module

[0072] 8. Brake actuator

[0073] 10 First Axle Modulator

[0074] 12 Second Axle Modulator

[0075] 14 First pressure sensor

[0076] 16 Second pressure sensor

[0077] 20 signal lines

[0078] 22 First valve device

[0079] 24 First memory interface

[0080] 26 Second valve device

[0081] 28 Second memory interface

[0082] 100 pneumatic system

[0083] 102 Electronically controlled pneumatic braking system

[0084] 200 vehicles

[0085] 202 Commercial Vehicles

[0086] 204 Rear Axle Braking Circuit

[0087] 206 Front axle braking circuit

[0088] 208 Parking Brake Circuit

[0089] 210 First Compressed Air Receiver

[0090] 212 Second Compressed Air Receiver

[0091] 214 Third Compressed Air Receiver

[0092] 220 Central Unit

[0093] 222 Vehicle Bus

[0094] 224 Units for autonomous driving

[0095] 226. Additional brake actuator (VA)

[0096] 228a, 228b Rear Axle Brake Actuator

[0097] 230 Front Axle Modulator

[0098] 232 Front axle brake signal circuit

[0099] 234a, 234b ABS valves

[0100] 236 Rear Bridge Modulator

[0101] 238 Rear Axle Brake Signal Circuit

[0102] 240 redundant central units

[0103] 242 Internal signal lines

[0104] 244 redundant front-bridge modulators

[0105] 246a and 246b redundant front axle ABS valves

[0106] 248 Redundant front axle brake signal circuit

[0107] 250 additional shuttle valves

[0108] 252 redundant rear bridge modulators

[0109] 254a, 254b Rear Axle Shuttle Valve

[0110] C cloud services

[0111] E Fault

[0112] ECU1 First Electronic Control Unit

[0113] ECU2 Second Electronic Control Unit

[0114] ECUZ central unit electronic control unit

[0115] G1 First pressure gradient

[0116] G2 Second pressure gradient

[0117] G4 Fourth Pressure Gradient

[0118] G1T First Pressure Gradient Variation Curve

[0119] G2T Second Pressure Gradient Variation Curve

[0120] G4T Fourth Pressure Land Change Curve

[0121] GS1 First Rated Variation Curve

[0122] GS2 Second Rated Variation Curve

[0123] GS4 Third Rating Variation Curve

[0124] GV1 First Comparison Value

[0125] GV2 second comparison value

[0126] GV4 Fourth Comparison Value

[0127] M memory

[0128] T1 First Tolerance

[0129] T2 Second Tolerance

[0130] p1 First pressure

[0131] p2 Second pressure

[0132] p3 Third pressure

[0133] p4 Fourth pressure

[0134] p5 Fifth Pressure

[0135] p6 Sixth Pressure

[0136] p6.2 The sixth pressure observed

[0137] pBHA Rear Axle Braking Pressure

[0138] pBVA Front axle braking pressure

[0139] pMAX maximum pressure

[0140] pV storage pressure

[0141] SP1 First Pressure Signal

[0142] SP2 Second Pressure Signal

Claims

1. A method for inspecting a shuttle valve (2) in a pneumatic system (100), wherein, The shuttle valve (2) has a first shuttle valve port (2.1), a second shuttle valve port (2.2), and a third shuttle valve port (2.3), wherein the higher of the pressures (p1, p2) applied at the first shuttle valve port (2.1) and the second shuttle valve port (2.2) is always regulated to the third shuttle valve port (2.3), wherein the method includes the following steps: a) Adjust the first pressure (p1) to the first shuttle valve interface (2.1); b) Obtain the indicated value (G1, G1T) for the first pressure (p1) at the first shuttle valve interface (2.1); c) Compare the indicated value (G1, G1T) for the first pressure with a predetermined first comparison value (GV1, GS1) set for this purpose, and if the deviation is greater than the first tolerance (T1): detect and / or output the fault (E) of the shuttle valve (2); d) Adjust the second pressure (p2) to the second shuttle valve interface (2.1); e) Obtain the indicated value (G2, G2T) at the second shuttle valve interface (2.2) for the second pressure (p2); and f) Compare the indicated value (G2, G2T) for the second pressure with a predetermined second comparison value (GV2, GS2) set for this purpose, and if the deviation is greater than the second tolerance (T2): know and / or output the fault (E) of the shuttle valve (2).

2. The method according to claim 1, wherein the method comprises the following steps: g) Compare the difference between the indicated value (G1) for the first pressure (p1) and the indicated value (G2) for the second pressure with a predetermined first threshold; and if the value is below the first threshold: detect and / or output a fault (E) in the shuttle valve (2).

3. The method according to claim 1, wherein, In step d), while the first pressure (p1) has been regulated to the first shuttle valve interface (2.1), the second pressure (p2) is regulated to the second shuttle valve interface (2.2).

4. The method according to any one of claims 1 to 3, wherein, The indicated value for the first pressure (p1) is the pressure gradient (G1), and the predetermined first comparison value (GV1) is the first comparison pressure gradient (GV1).

5. The method according to any one of claims 1 to 3, wherein, The indicated value for the first pressure (p1) is the pressure gradient change curve (G1T), and the predetermined first comparison value is the rated change curve (GS1).

6. The method according to any one of claims 1 to 3, the method comprising the following steps: - Adjust the second shuttle valve interface (2.2) to produce a third pressure (p3) that is less than the maximum pressure (pMAX); - A fourth pressure (p4) is regulated to the first shuttle valve interface (2.1), wherein the fourth pressure (p4) is higher than the third pressure (p3). - Obtain the pressure gradient change curve (G4T) with respect to time (t) at the first shuttle valve interface (2.1); - To know the deviation between the known pressure gradient change curve (G4T) and the predetermined rated change curve (GS4); and when a deviation is confirmed: to know and / or output the fault (E) of the shuttle valve (2).

7. The method according to any one of claims 1 to 3, the method comprising the following steps: - Adjust the fifth pressure (p5) to the first shuttle valve interface (2.1); - During the regulation of the fifth pressure (p5), a sixth pressure (p6) is regulated to the second shuttle valve interface (2.2), wherein the sixth pressure (p6) is a very small pressure; - Detect the pressure (p6.2) applied to the second shuttle valve interface (2.2) over a period of time; and when the pressure (p6.2) applied to the second shuttle valve interface (2.2) rises: detect and / or output the fault (E) of the shuttle valve (2).

8. The method according to claim 7, wherein the method comprises the following steps: - Release the first shuttle valve port (2.1) from the fifth pressure (p5) to the ambient pressure (p0) and regulate the second shuttle valve port (2.2) to the sixth pressure (p6); - Detect the pressure (p6.2) applied to the second shuttle valve interface (2.2) for a period of time; and when the pressure (p6.2) applied to the second shuttle valve interface (2.2) remains within a predetermined tolerance: detect and / or output the fault (E) of the shuttle valve (2).

9. The method according to any one of claims 1 to 3, the method comprising the following steps: - Obtain the current reservoir pressure (pVT); wherein step c is performed at least in consideration of the known current reservoir pressure (pVT).

10. The method according to any one of claims 1 to 3, wherein, At least the predetermined first comparison value is a value learned from previously measured values.

11. The method according to any one of claims 1 to 3, the method comprising the following steps: - Recall at least the predetermined first comparison value (GV1, GV2, GV4) from the internal storage medium (M) and / or wirelessly from the cloud service (C).

12. The method according to any one of claims 1 to 3, wherein, The first valve module (4) is connected to the first shuttle valve interface (2.1), and the second valve module (6) is connected to the second shuttle valve interface (2.2), wherein the first and second valve modules (4, 6) communicate with each other electronically, either indirectly or directly, and wherein the third shuttle valve interface (2.3) is connected to the consumer.

13. The method according to claim 12, wherein, The steps are performed during braking of the vehicle (200), wherein the first pressure (p1) is a first braking pressure (pB1, pBVA, pBHA) for braking the vehicle (200).

14. The method according to claim 12, wherein, The steps are performed when the vehicle is stationary, wherein the method further includes the following steps: - Receive a departure control signal to implement departure control; and in response to receiving the departure control signal: at least perform steps a) to c).

15. The method according to claim 1, wherein, The pneumatic system (100) is an electronically controlled pneumatic braking system (102).

16. The method according to claim 12, wherein, The first valve module (4) is configured as a first axle modulator (10).

17. The method according to claim 12, wherein, The second valve module (6) is configured as a second axle modulator (12).

18. The method according to claim 12, wherein, The consumer is configured as a braking actuator (8).

19. A pneumatic system (100) for a vehicle (200), said pneumatic system having A shuttle valve (2) having a first shuttle valve interface (2.1), a second shuttle valve interface (2.2), and a third shuttle valve interface (2.3), wherein, The higher of the pressures (p1, p2) applied at the first shuttle valve port (2.1) and the second shuttle valve port (2.2) is always regulated to the third shuttle valve port (2.3). A first valve module (4) is connected to the first shuttle valve interface (2.1) to regulate a first pressure (p1) to the first shuttle valve interface, and has a first pressure sensor (14) for detecting an indication value for the first pressure (p1); The second valve module (6) is connected to the second shuttle valve interface (2.2) to regulate a second pressure (p2) to the second shuttle valve interface, and has a second pressure sensor (16) for detecting the indicated value for the second pressure (p2); and An electronic control unit (ECU1, ECU2) is connected to a first and a second valve module (4, 6) for receiving first and second pressure signals (SP1, SP2) from a first and a second pressure sensor (14, 16), wherein the electronic control unit (ECU1, ECU2) further has devices suitable for implementing the steps of the method according to any one of claims 1 to 18.

20. The pneumatic system (100) according to claim 19, wherein, The first valve module (4) is configured as a first axle modulator (10), and the second valve module (6) is configured as a second axle modulator (12), wherein the third shuttle valve interface (2.3) is connected to the brake actuator (8) in a fluid-guiding manner.

21. The pneumatic system (100) according to claim 20, wherein, The first axle modulator (10) is constructed and configured for normal operation of the vehicle (200), and the second axle modulator (12) is constructed and configured for a redundancy situation in which the first axle modulator (10) is not working or is not working properly.

22. The pneumatic system (100) according to any one of claims 19 to 21, wherein, There are no additional sensors in the path downstream of the third shuttle valve interface (2.3).

23. The pneumatic system (100) according to claim 19, wherein, The vehicle in question is a commercial vehicle (202).

24. The pneumatic system (100) according to claim 19, wherein, The pneumatic system (100) is an electronically controlled pneumatic braking system (102).

25. A vehicle (200) having a pneumatic system (100) according to any one of claims 19 to 24.

26. The vehicle (200) according to claim 25, wherein, The vehicle (200) is a commercial vehicle (202).

27. A computer program comprising instructions that cause the pneumatic system (100) according to claim 19 to perform the steps of the method according to claim 1.

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