Vehicle Bearing Unit Condition Monitoring Unit, System and Method

Abstract

A condition monitoring system for a vehicle bearing unit, the system comprising at least one condition monitoring unit (10) for measuring at least one operating parameter of a bearing unit and a control unit (18) for receiving and processing signals obtained by the condition monitoring unit (10). Means (19) for detecting a geographical location are also provided, wherein the condition monitoring unit (10) is configured to be started and / or deactivated based on the detected geographical location.

Description

[0001] This application is a divisional application of a Chinese patent application with application number 201510769963.2, application date November 12, 2015, applicant SKF AB, and invention title "Condition Monitoring Unit, System and Method for Vehicle Bearing Units". Technical Field

[0002] The present invention relates to a condition monitoring system for use in a vehicle to monitor the condition of a wheel axle or bearing unit, a condition monitoring unit for such a system, and a method of monitoring the condition of a bearing or wheel axle. In particular, the present invention relates to a monitoring system for a train wheel axle and / or bearing. Background Art

[0003] It is known to connect a condition monitoring unit to a train wheel axle or its bearing to monitor parameters such as vibration, temperature and acoustic emissions.

[0004] In the vehicle field, there are various wired sensors, many of which are related to the Engine Control Unit (ECU) and the On Board Diagnostic (OBD) system. These sensors are fully integrated into the vehicle's infrastructure so that they have a continuous power supply during vehicle operation. Data communication is supported by the Controller Area Network (CAN) bus. These sensor systems operate continuously to monitor their target parameters.

[0005] The locomotive and passenger carriages also have a fully integrated series of sensor systems, but these sensor systems usually relate to safety-critical functions. However, some train carriages, especially those related to freight, do not have an integrated sensor system or infrastructure to support them.

[0006] In recent years, the use of wireless sensor systems in vehicles has been steadily increasing. With the advent of wireless sensor systems, more components of a rotating mechanism can now be monitored compared to before, including components that were previously considered difficult to access. Their applications are usually related to rotating components such as drive shafts and bearings.

[0007] Many of these applications require the wireless sensors to be placed in locations where a wired power supply cannot be achieved. Although there are many mechanisms that can be used to help with energy harvesting at the location of the wireless sensors, they often cannot be achieved in a given situation and usually still need to rely on an energy storage device such as a battery. One consideration in the design of wireless sensor systems is the maintenance interval, which is usually determined by the life of their batteries. Therefore, power management is an important factor in the design of wireless sensor systems because it has a direct impact on the maintenance interval.

[0008] Currently available condition monitoring solutions with a permanent power supply are set to continuously acquire data. However, the acquired data usually contains a large amount of artefacts, and the measured curves reflect the curvature of the track, track defects, and other external influences. Therefore, it is necessary to use complex algorithms to filter the data to eliminate artefacts, and it is necessary to extract valuable and reliable information about the bearing condition from the large amount of data.

[0009] Another issue relates to the power consumption of the sensors included in the condition monitoring unit. Currently, the sensors are battery-powered, and the battery life depends on the time spent activating the sensors. The prior art has addressed the limited battery life problem by replacing the battery with a generator integrated in the axle box to meet the growing demands of railway transportation. This issue is of particular significance for systems such as electronic data transmission systems that require data transmission at short time intervals, transmit a large amount of data, or use active sensors that require a power supply.

[0010] There has been no attention paid to power saving, and there is a technical bias against the concept of power saving because these systems are generally considered safety systems.

[0011] Satellite-based positioning systems such as GPS navigation systems have become popular, especially in motor vehicles. Currently, there is a range of off-the-shelf low-cost GPS devices and chipsets. Therefore, many vehicle manufacturers have considered developing this technology to provide additional features for their customers. These products are extensive and diverse, ranging from providing basic location information to emergency contact services regarding location and vehicle condition after an accident. An opportunity that is popular among vehicle manufacturers is related to providing diagnostic information about the vehicle during servicing or repair.

[0012] The currently considered system can determine the nearest dealer / repair shop, retrieve diagnostic codes from the vehicle's OBD system, and send the data to the repair shop via a mobile phone. Patent US7142959B2 discloses an example of this system. For some obvious reasons, GPS systems are not common in railway vehicles, but asset tracking systems based on technologies such as those disclosed in patent US6339397B1 are available.

[0013] These GPS systems used in automobiles are related to operation / diagnostic data, mainly related to determining the nearest appropriate facility, or providing vehicle location information to initiate a more centralized system for such determination.

[0014] Furthermore, it has been proposed to provide geo-boundaries or GPS gates to provide a location-based triggering mechanism. Examples of such systems are disclosed in patents US7319412B1 and US2010 / 0156712A1. Such systems are mainly used for security-related products, for example, for tracking or identifying criminals regarding unauthorized movement of a vehicle. Although these systems provide a potential location-based triggering mechanism, they are mainly used to initiate an information system to provide limited information to a higher-level system. Even considering vehicle diagnostic information, the system simply transmits codes from an OBD system. Summary of the Invention

[0015] The present invention is directed to solving the above problems of the prior art by providing a condition monitoring system having a long service life and reduced complexity in data processing.

[0016] A first aspect of the present invention relates to a condition monitoring system for a vehicle bearing unit, the system comprising at least one system monitoring unit for measuring at least one operating parameter of a bearing unit and a control unit for receiving and processing signals from the condition monitoring unit.

[0017] It is proposed that the system further comprises means for detecting the geographical location of the vehicle or the condition monitoring unit, wherein the condition monitoring unit is configured to be enabled and / or disabled according to the detected geographical location.

[0018] The advantage of the possibility of triggering monitoring according to the geographical location is that the acquisition of data can be limited to a part of the track or the vehicle route, in which case reliable data is expected to be collected. This solution can repeatedly determine when and where to trigger data recording.

[0019] The present invention greatly simplifies power management by providing reliable triggering, enabling the system to operate on an intermittent basis rather than continuously. Not only is the optimal operating cycle determined, but also the optimal operating cycle is implemented, thus achieving an intermittent operating strategy that can pose a challenge. Triggering the system to start an operating cycle can be difficult to achieve, and using a simple time trigger to minimize energy consumption is not sufficient.

[0020] Taking into account the need to minimize energy consumption, the present invention enables the sensor systems to operate only when their monitoring of the components is necessary or can produce the most effective results. When the mechanical devices being monitored are part of a moving system such as a train, external factors also need to be considered. The nature of these external factors varies, and their relevance is usually related to the parameters of interest of the wireless sensor system. For example, if the sensor system is monitoring the axle bearings on a train, the nature of the track on which the train travels is highly relevant. The axle bearings may reach their maximum and minimum loads in the curved sections of the track, and these points can affect the sensor data.

[0021] The nature of the parameters being monitored usually determines the methods employed. It is also necessary to consider the termination of the operating cycle. Additionally, when dealing with a moving system such as a vehicle, it may be necessary to transfer data from the wireless sensor system to an external system. When short-range RF communication is used and the external system is a fixed device, it may be appropriate to consider using a location-based trigger communication system, i.e., triggering the communication system only when the external system is within the communication range.

[0022] When monitoring rotating mechanical devices, it is usually useful to be able to collect data during steady-state operation and minimize noise from unwanted sources. If we consider the example of a wireless sensor system for monitoring train axle bearings, this is equivalent to traveling at a constant speed within a specified speed band in good condition on a straight track. In this simple example, we assume that the train has a fixed route and passes a certain distance of the straight track at a constant speed once a day. The paths immediately before and after this track section in the route are more curved and pass through numerous points that can cause a significant reduction in the quality of the data collected from this part of the route. In this case, it is also highly desirable to collect data from exactly the same track section every day, which enables analogies to be made between the data. The sensor system "sleeps" to save energy before reaching this track section, but it needs to be fully operational and collect data within a given time or at a given distance along the track. All of the above objectives can be easily achieved by the present invention.

[0023] In the case where the train travels the same route every day, it is possible to simply use a clock as a basis to make a "wake-up" call at the same time every day and operate for a fixed period of time. However, even the most punctual rail systems may experience unpredictable delays, which makes it difficult to use this method. As a result, it is very likely that variations in the starting position of the sensing operation will lead to a lower quality of the data collected and potentially be associated with different operating conditions. In this case, the main requirement for ensuring consistency is a location-based trigger system.

[0024] There are existing wayside systems that can be used both to track the movement of trains and to be associated with hot box detection. These wayside systems may serve as position markers. Unfortunately, these wayside devices may be at a certain distance from the track sections to be monitored and may also be placed on different sides of the tracks at different locations. Identifying these wayside devices is very difficult without installing additional devices for monitoring operation or integrating additional devices into the wayside system. Neither of these two options is satisfactory.

[0025] However, combining a GPS navigation system and a monitoring system can provide a basis for a location-based triggering system without the need for infrastructure. Such a mechanism enables a wireless sensor system to monitor parameters of interest each time a train passes the same location on the track, regardless of the time or frequency of its daily passage through that track section.

[0026] The present invention combines the functions of a GPS system with a wireless sensor system to optimally control the intermittent monitoring operation of vehicles and other mobile machinery. This is different from its standard usage method in which the operation of the sensor is continuous. Therefore, a method has been developed that uses GPS position information as the start and stop trigger for the operation of the wireless sensor.

[0027] In the case of the present invention being applied to track-based or road-based vehicles, no complex geographical boundaries / gates are required. Instead, road signs are used as the basis for triggering a series of operations of the wireless sensor system. The road signs can be manually input into the system locally or remotely.

[0028] Alternatively, the GPS-based triggering system is equipped with map data and details of the driving route, which can identify possible road signs from the specific requirements of the monitoring to be implemented.

[0029] This method requires relying on a route map to compare user requirements. Based on a similar principle, a more advanced system can also be developed, in which the GPS system input can be used to generate a detailed route map before being used to control the sensor system. The latter method can generate a more detailed route map than that obtained by using only general map data and is beneficial for discovering useful features of the route. In the simplest case, this can help notify the user that a particular track section is very noisy or that the train's operation is too unstable to consider using the wireless sensor system thereon; alternatively, it can be used to identify specific situations in which monitoring by the wireless sensor is useful.

[0030] To ensure continuous and reliable data reading, the status monitoring unit should collect data in known high-quality track sections. Preferably, the track or route should be straight, level and allow the train to reach and maintain a constant speed. Additionally, these track trigger coordinates are used as reference points for the trends of all measurement data and thus also as references for the same points on the track or route.

[0031] The system can be applied to any type of vehicle, particularly including trains and trucks.

[0032] By powering on and recording data within a short time period that meets suitable conditions, the energy consumption can be significantly reduced. Triggering measurements in known track sections reduces data acquisition errors or anomalies and optimizes energy utilization. The reduction in energy consumption allows for the use of a generator or energy harvesting device with a reduced rated power, or the battery life can be extended.

[0033] According to another aspect of the present invention, it has been proposed that the control unit is equipped with a memory for storing route data of the vehicle, the route data including a plurality of route segments along which the vehicle may travel, wherein the control unit is arranged to: activate the status monitoring unit when the vehicle is traveling on one of the route segments in a predetermined group of route segments, and deactivate the status monitoring unit when the route segment where it is located is not included in the predetermined group of route segments. The predetermined group of routes or track sections can be selected such that high-quality data as described above can be expected.

[0034] In another embodiment of the present invention, the control unit is equipped with a memory for storing route data of the vehicle, the route data including a plurality of route segments along which the vehicle may travel, wherein the control unit is configured to evaluate at least one characteristic of the route segments in the route data, and activate the status monitoring unit when the characteristic of the route segment on which the vehicle is traveling meets at least one predetermined criterion, and deactivate the status monitoring unit when the characteristic of the route segment does not meet the at least one predetermined criterion. The control unit can automatically evaluate the parameters of the next route or track section and activate the status monitoring unit when the criterion is met. The parameters can include but are not limited to slope, curvature or degree of bend, and the number of expected stops and departure stations of the vehicle.

[0035] In a preferred embodiment of the present invention, the device for detecting the geographical location includes a device for receiving signals from satellites of the Global Positioning System (GPS). It is considered that GPS provides the most suitable enabling mechanism to meet the requirements of the system according to the present invention.

[0036] A GPS system integrated in a system control unit located in a train or a truck can accurately monitor and determine the position and speed of the train. Long and straight track sections suitable for obtaining data can be identified, and the coordinates can be programmed into the control unit. When these coordinates are reached, the central control unit can issue an instruction to wake up the status monitoring unit from the sleep mode, convey the appropriate train speed, and trigger data measurement. If the correct GPS and / or speed conditions are not met, data recording will not be performed, thus saving energy.

[0037] The combined triggering of the automatic "awakening" of the status monitoring unit, the start of data recording, and the return to the "sleep mode" by the GPS position and the track network map is a very effective method, which can reduce the energy consumption and the computational complexity of data processing as described above.

[0038] Another aspect of the present invention relates to the status monitoring system as described above, wherein the status monitoring unit includes a battery as an energy source. The present invention is particularly advantageous in this case. By powering on and recording data for a short period of time when the correct conditions are met, the battery life can be significantly extended. By triggering measurements in known track sections, data acquisition errors or anomalies are reduced, and the energy utilization of the battery is optimized.

[0039] According to another aspect of this aspect, it is proposed that the status monitoring unit is configured to communicate with the control unit wirelessly. In a wiring harness system, the power supply problem is obviously less serious.

[0040] In a preferred embodiment of the present invention, it is proposed that the device for detecting the geographical location is part of a control unit located in the center of the vehicle, such as in the locomotive of a train or the cargo box of a truck. The existing GPS receiver of the vehicle control system can be used.

[0041] As an alternative embodiment of the present invention, it is proposed that the device for detecting the geographical location is part of a status monitoring unit connected to a bearing unit. The device for detecting the geographical location can be a simple GPS receiver known in mobile phone technology, which is small enough to be integrated into the status monitoring unit in / on the axle box.

[0042] In a preferred embodiment of the present invention, the status monitoring unit is configured to be connected to a wheel hub unit of a train, wherein the control unit is configured to monitor the status of a plurality of wheel hub units of the train.

[0043] Another aspect of the present invention relates to a status monitoring unit for use in a status monitoring system as described above, wherein the status monitoring unit includes a controller configured to operate in an energy-saving sleep mode and an activation mode, wherein at least some parameters are monitored in the activation mode and not monitored in the sleep mode, and wherein the controller is configured to switch the status monitoring unit from the sleep mode to the activation mode and from the activation mode to the sleep mode based on signals received by the controller.

[0044] Further, it is proposed that the controller is configured to switch the status monitoring unit from the sleep mode to the activation mode for performing status monitoring when a wake-up signal is received from a vehicle control unit, and to switch the status monitoring unit from the activation mode to the sleep mode when a sleep signal from the control unit is received.

[0045] Another aspect of the present invention relates to a method for monitoring the status of a vehicle bearing unit, which uses at least one status monitoring unit for measuring at least one operating parameter of a bearing unit and a control unit for receiving and processing signals obtained by the status monitoring unit.

[0046] Further, it is proposed to detect the geographical location of the vehicle and activate and / or deactivate the status monitoring unit according to the detected geographical location.

[0047] The present invention enables selective data acquisition, wherein data is only acquired from known good track sections. The advantages include the following:

[0048] Data measurements are all referenced to the same point on the track, so each measurement is comparable to the previous one, making analysis and data trends easier;

[0049] Battery life is increased because the sensor only starts for a short period of time when suitable conditions are met;

[0050] Low-cost solution, only requiring an external GPS antenna and a GPS module in a PC.

[0051] Another aspect of the present invention relates to a method for triggering synchronous measurements by multiple nodes at a specified geographical location. This can reduce the impact that the track status may have on the measurement results collected by the sensors. This helps to ensure that the measurement quality of all sensors remains consistent. Coupling GPS and a time-synchronized sensor network can also be used to provide this feature.

[0052] Another aspect of the present invention relates to the use of the system specifically described above for measuring track quality and using the track quality as a tool for infrastructure monitoring. Since the wireless sensors are configured to acquire bursts of acoustic emissions and vibrations at specific locations, they can also be used to characterize the condition of a track section at a specific location. In cases where railway operators suspect that a particular track section may be damaged, which may in turn cause discomfort to passengers or damage to rail vehicles, the system can be configured to acquire data on these specific sections, enabling railway operators to identify trend degradation or confirm whether the track is actually damaged.

[0053] The following non-limiting description of embodiments of the present invention, together with the appended claims and drawings, shows several distinct features of the present invention in specific combinations. A person skilled in the art should be able to readily conceive of further combinations or sub-combinations of these features so that the invention defined in the claims can be adapted to his or her specific needs. Description of the Drawings

[0054] Figure 1 is a schematic diagram of a train including a condition monitoring system for a vehicle bearing unit according to the present invention; and

[0055] Figure 2 is a system component diagram of the monitoring system according to the present invention;

[0056] Figure 3 is an example of a waymark alarm activity algorithm in the monitoring method according to the present invention. Detailed Description of the Invention

[0057] Figure 1 is a schematic diagram of a train including a condition monitoring system for a vehicle bearing unit according to the present invention. The system includes a plurality of condition monitoring units 10, that is, one is provided on each wheel of the train for measuring at least one operating parameter of a bearing unit of a train axle box. The condition monitoring unit 10 is formed as a wireless sensor node, which is connected to or embedded in an end plate (not shown) of a double-row roller bearing assembly of a wheel hub. The measured operating parameters include vibration, acoustic emission, and bearing temperature, and each condition monitoring unit 10 includes a corresponding sensor 12.

[0058] A system concentrator serving as a control unit 18 is provided in the locomotive of the train for receiving and processing signals obtained by the condition monitoring units 10. The control unit 18 is essentially a personal computer equipped with software for controlling and monitoring various mechanical devices of the train and for issuing warning signals based on signals received by the condition monitoring units 10 in the event of detecting a dangerous or potentially dangerous situation.

[0059] The communication between the control unit 18 and the status monitoring unit 10 is at least partially wireless and uses the antenna 17a. If necessary, each carriage or part of a carriage is provided with a remote network manager 15 to act as a wireless network manager, a power supply manager for the unit 10, and a wireless network extender. The wireless network can be a single-band 2.4 GHz network or a dual-band 2.4 GHz and 5 GHz network. Those skilled in the art can use other communication frequencies or other communication protocols according to the environment, including different protocols for the backbone network and for the communication between the extender and the unit 10.

[0060] The control unit 18 is also equipped with a GPS antenna 17c and an antenna 17b for a mobile communication interface, and the mobile communication interface adopts standards such as GSM, GPRS, UMTS, LTE, or HSDPA.

[0061] In Figure 1 the embodiment of, the control unit 18 includes a GPS receiver 19, which is used to receive position signals from the satellite system 30 so as to act as a device for detecting the geographical location. The system is configured such that the status monitoring unit 10 is started and / or deactivated according to the detected geographical location, which will be further explained below.

[0062] Figure 2 A system component diagram of the monitoring system according to the present invention is shown.

[0063] The status monitoring unit 10 is provided with a controller 14, a transmitter 16 for wireless communication, and a battery for supplying power to the sensor, the controller 14, and the transmitter 16.

[0064] The control unit 18 is equipped with a memory 20 for storing vehicle route data and other data, and the other data includes sensor data acquired by the sensor 12. In this embodiment, the vehicle is a train and the route data is a railway network map. In other embodiments, the route data can be a collection of road signs or a database. The railway network includes a plurality of sections or connection segments stored in the database in the memory 20 and parameters describing the nature of the sections, such as slope, average curvature, and maximum allowable driving speed. The database in the memory 20 includes a plurality of route segments along which the vehicle may travel.

[0065] The trigger designer 22 is configured to set trigger points at appropriate sections of the track for starting the status monitoring unit 10 having the sensor 12. Deactivation trigger points can also be set by the trigger designer 22. In an alternative embodiment, the status monitoring unit 10 can be deactivated after a predetermined period of time. The trigger designer 22 can be part of the control unit 18 or part of a remote server, and the remote server uses a mobile communication interface to send the trigger points to the control unit 18.

[0066] Each trigger point is a data structure that includes not only GPS coordinates but also an optional field indicating the direction of travel of the train for which monitoring should be triggered. Additionally, the data structure can include fields for upper and lower speed limits, and in one embodiment of the invention, a field for a radius, which is the minimum distance from the GPS coordinates required to trigger a wayside alarm. Accordingly, the system can be configured such that an alarm is not triggered every time the train passes the wayside, but rather when the train passes in one of the two possible directions on the track and when the speed is within a desired range suitable for obtaining high-quality measurement results.

[0067] In the embodiment of the figure, the trigger designer 22 is a graphical interface application (GUI) program for planning data collection waysides on the train route. These may particularly include true coordinate points on a straight path, where the speed is known to be constant in the case of a straight path. The trigger designer 22 in this embodiment provides a Keyhole Markup Language (KML) file or other type of standard file format (such as GML), which is standard for GIS data used by various map providers. This general file can be used by the server of the condition monitoring system to download and use the waysides or trigger points stored in the trigger design database 23.

[0068] The trigger point is the starting point of a route segment that is part of a predefined group of route segments in which data collection by the condition monitoring unit 10 should be initiated.

[0069] When the train passes a trigger point, that is, enters a new route segment included in the predefined group of route segments, the control unit 18 is configured to start the condition monitoring unit 10 by sending a wake-up signal. When the train passes a deactivation trigger point, that is, leaves a route segment for which measurements should already have been performed, the control unit 18 deactivates the condition monitoring unit 10 by sending a sleep signal.

[0070] After the measurement is completed, the measurement data is stored in the memory 20 and sent to the remote condition monitoring server using the mobile communication interface of the control unit 18.

[0071] In a preferred embodiment of the invention, the GPS module 27 is implemented as a program library or a GPS processing thread of the control unit 18. It will have the necessary functions to obtain GIS data from the Global Navigation Satellite System (GNSS) receiver 19. A thread in the control unit 18 downloads software modules and starts GPS message interpretation. This thread is managed by option settings in the service manager of the control unit 18. If the GPS option is selected and the appropriate KML data is downloaded, the thread is started.

[0072] After startup, the GPS module 27 automatically connects to the GPS device and detects the connected simulator. Subsequently, the GPS system listens to and interprets information about position, speed, and direction, which is encoded according to the standards set by the National Marine Electronics Association (NMEA). Subsequently, the data received from the trigger designer 22 is used to update the trigger design database 23 in memory and the set of waypoints in the memory 20. Based on the position, the GPS system determines the waypoint arrival of each provided waypoint and notifies the customer when the waypoint is reached.

[0073] The system also includes a server management application 21 that provides configuration data, an acquisition application 24 for manually triggering measurements, a device management application 25 for managing the settings of the on-vehicle unit 10, and a communication server 26.

[0074] Optionally, the GPS system monitors speed changes that exceed the tolerance limit (if any) and notifies of the change. To this end, the NMEA information is repeatedly received and processed until a stop message is received. After stopping, the necessary cleanup is carried out.

[0075] Figure 3 A more detailed description of the waypoint alert activity algorithm executed in the GPS module 27 is shown, which determines Figure 3 the waypoint arrival of the waypoints. The GPS module starts and operates on two parallel paths. In Figure 3 the left hand side of Figure 3 waypoint processing is shown, while in

[0076] the right hand side of

[0077] In an embodiment where a radius for a road sign is set, the radius should be set to be less than the search radius, and a road sign alert should be triggered only when the distance to the road sign is both within the search radius and within the radius for the road sign. Once a road sign alert is generated, the road sign is marked as processed.

[0078] This radius avoids triggering at missed road signs, and it also makes the setting of road signs easier because the setting does not need to be 100% accurate. The receiver has errors due to GPS signal reflection and is sometimes slightly inaccurate.

[0079] A trigger radius is set around the perimeter of the road sign. This can be used, for example, in a situation where the road sign is several meters away from the railway track and not directly on it. The user can specify that if the receiver is within 100m or within any other appropriate distance from any road sign, it should be triggered. This is also useful when the user wants to trigger at a very specific point on the track, perhaps for track quality assessment. This can be achieved by setting a smaller radius.

[0080] An alternative method of triggering the measurement is facilitated by the system, in which case the precise network time is specified as the measurement start time. The system application software monitors the position data continuously provided by the GPS module and estimates the time required to reach the road sign position. Before reaching the road sign, the system application software sends a broadcast message to the gateway manager via TCP / IP to instruct the nodes to trigger at a given future network time. When that time arrives, each node performs the measurement and stores the data together with the time indicating the stored data set internally.

[0081] In another embodiment of the present invention, the control unit 18 does not rely on a predetermined instruction in the map data, but instead the control unit 18 online evaluates whether the next route segment is likely to meet a predetermined standard based on the route data and using the characteristics of the route segment stored in the route data. Subsequently, the control unit 18 activates the status monitoring unit 10 when the characteristics of the route segment traveled by the vehicle meet the standard, and deactivates the status monitoring unit 10 when the characteristics of the route segment traveled by the vehicle do not meet the predetermined standard. The activation and deactivation can further depend on other parameters, such as the traveling speed, the external temperature, and the time elapsed since the last activation.

[0082] As described above, the status monitoring unit 10 used in the above status monitoring system includes a controller 14, which is configured to operate in an energy-saving sleep mode and a startup mode. The controller 14 is configured to switch the status monitoring unit 10 from the sleep mode to the startup mode and from the startup mode to the sleep mode based on signals received by the controller 14 from the control unit 18 via the transmitter 16. More specifically, the controller 14 is configured to switch the status monitoring unit 10 from the sleep mode to the startup mode for running status monitoring when receiving a wake-up signal from the control unit 18, and to switch the status monitoring unit 10 from the startup mode to the sleep mode when receiving a sleep signal from the control unit 18.

[0083] The above system implements a method for monitoring the status of a vehicle bearing unit, which uses at least one status monitoring unit 10 to measure at least one operating parameter of a bearing unit, and uses a control unit 18 to receive and process signals obtained by the status monitoring unit 10, wherein the geographical location of the vehicle is detected and the status monitoring unit 10 is started and / or deactivated according to the detected geographical location.

[0084] Another aspect of the present invention relates to a method for triggering synchronous measurements by multiple nodes at a specified geographical location, which is expected to reduce the impact that the track status may have on the measurement results collected by sensors. In the case of a long train, the geographical location of the control unit 18 may be substantially different from the geographical location of a specific axle box. This helps to ensure that the measurement quality of all sensors remains consistent. The coupling of a GPS and a time synchronization sensor network can also be used to provide this feature.

[0085] Another aspect of the present invention relates to using the system specifically described above to measure the track quality and using the track quality as a tool for infrastructure monitoring.

[0086] Considering the example of the above train, the GUI trigger designer 22 application in the central control unit 18 is used to pre-record the road sign coordinates in the database, and the control unit 18 manages the operation of the monitoring system as a central hub.

[0087] The hardware GNSS receiver module receives GIS signals from multiple satellites 30 and converts the signals into information in NMEA format for the GPS module. The GPS module continuously provides the application software with location information containing longitude and latitude data, and the PC application can use this location information to determine the approximate distance (and approximate arrival time) to the target road sign.

[0088] Once reaching the landmark position, the GPS module creates an exception message and determines whether various parameters are met before proceeding to the next step, including determining that the train is operating within the acceptable speed range configured in the system and that the change in speed itself is within the specified deviation. If these conditions are accepted, the system software continues to run to mark the exception and trigger a broadcast message to all nodes on the network. This includes transmitting the message to all gateway managers on the network via TCP / IP. Once the message is received, each gateway manager wirelessly forwards the broadcast message to the status monitoring unit 10 acting as a sensor node.

[0089] When each status monitoring unit 10 receives the message, it starts data capture, powers the acquisition circuit for a period of time before storing the recorded data, and then shuts down the circuit. The data can be unloaded directly after capture or later. Subsequently, the node re-enters the low-power state until the central control unit 18 requests it to perform another measurement or task.

[0090] In the case of a manually requested measurement, the system does not require GPS data. If GPS is not used, default speed and empty position values are used. When GPS is available, the speed and position are obtained from the GPS module. Subsequently, a broadcast message is sent. Once the status monitoring unit 10 receives the broadcast command message, it performs the necessary sampling according to the pre-configured settings and the recommended speed.

[0091] The application software in the control unit 18 maintains a dynamic table in the database to adjust the received data and use it as feedback for the broadcast command. This is to prevent data loss during power failures or connection problems. The dynamic data needs to be refreshed at a predetermined time interval.

[0092] As an optional feature, the GPS module continuously reports speed changes, and if a speed change event is processed, the database is updated accordingly.

[0093] When all the data is received, the date / time and speed are compared with the database to determine any speed changes. If the speed remains constant, the sample is recorded and a waveform is requested. If any observed speed change value exceeds the threshold, the sample is considered invalid and not stored in the database.

[0094] Upon reaching a landmark, the status monitoring unit 10 is triggered by the control unit 18 to "wake up" and start operating. For this purpose, the method used by the trigger designer 22 first determines the appropriate landmark position based on speed, position, and track conditions, and then inputs the landmark parameter details into the on-vehicle software running on the control unit 18. According to the data input by the trigger designer 22, there is one or more operating cycles on the train route.

[0095] Wireless sensor systems associated with monitoring wheel bearings typically have means for detecting the rotational speed of the wheel and, therefore, have some ability to adapt to speed changes.

[0096] However, a sensor system with wheel rotation detection may not require speed information on straight sections of the track. Embodiments using a condition monitoring unit 10 without rotation detection can benefit from GPS-generated data for speed calculation. A simple solution only requires a starting point and an ending point, which are either coupled to the time data of the GPS system or use the wireless sensor system clock, but the system lag of GPS may cause some problems, especially when acceleration information is required.

[0097] In another embodiment of the present invention, the condition monitoring system may include an Inertial Navigation System (INS). Further, the condition monitoring unit 10 can be equipped with a 3-axis or 6-axis accelerometer or gyroscope, and the data measured by these devices can be used to process waveforms and / or determine the reliability of the data. This will be able to improve the control of the sensor system and provide additional environmental information to assist data processing by integrating some track-related variables in addition to accurate acceleration measurement results.

[0098] Taking these factors into account helps to maintain the consistency of the conditions for performing the monitoring. It can also be shown that providing angular acceleration and speed readings when monitoring in curved sections of the track is useful. After all, these same operating principles are not simply applied to straight sections of the track, but to any track section on which the train operates. For example, monitoring the bearing under maximum load can provide useful information.

Claims

1. A condition monitoring system for a vehicle bearing unit, the system comprising at least one condition monitoring unit (10) for measuring at least one operating parameter of a bearing unit and a control unit (18) for receiving and processing signals obtained by the condition monitoring unit (10). It is characterized in that It further comprises means (19) for detecting the geographical location of the vehicle, wherein the condition monitoring unit (10) is configured to be started and / or deactivated according to the detected geographical location, and further comprises an acquisition application (24) for manually triggering measurements; The control unit (18) comprises a trigger designer (22) configured to set trigger points for starting the condition monitoring unit (10) having sensors (12); The deactivation trigger points are also set by the trigger designer (22); Wherein, the condition monitoring unit (10) is started and deactivated according to the geographical location and the driving direction of the vehicle relative to the trigger point.

2. The state monitoring system according to claim 1, characterized in that The control unit (18) is equipped with a memory (20) for storing route data of the vehicle, the route data including a plurality of possible route segments along which the vehicle can travel, wherein the control unit (18) is configured to: start the condition monitoring unit (10) when the vehicle is traveling on one of the route segments in a predetermined set of route segments, and deactivate the condition monitoring unit (10) when the vehicle is traveling on a route segment not included in the predetermined set of route segments.

3. The state monitoring system according to claim 1, characterized in that The control unit (18) is equipped with a memory (20) for storing route data of the vehicle, the route data including a plurality of possible route segments along which the vehicle can travel, wherein the control unit (18) is configured to: evaluate at least one feature of the route segments in the route data, start the condition monitoring unit (10) when the feature of the route segment on which the vehicle is traveling meets at least one predetermined criterion, and deactivate the condition monitoring unit (10) when the feature of the route on which the vehicle is traveling does not meet the at least one predetermined criterion.

4. The state monitoring system according to claim 1 described above, characterized in that The control unit (18) is equipped with a memory (20) for storing the coordinates of a plurality of road signs and at least one radius, wherein the control unit (18) is configured to: start and / or deactivate the condition monitoring unit (10) when the distance between at least one of the road signs and the detected geographical location is less than the radius.

5. The state monitoring system according to claim 1 above, characterized in that The memory (20) of the control unit (18) is configured to store the driving direction associated with at least one road sign, wherein the control unit (18) is configured to: start and / or deactivate the condition monitoring unit (10) when the distance between at least one of the road signs and the detected geographical location is less than the radius and further when the driving direction of the vehicle matches the driving direction stored in association with the at least one road sign.

6. The state monitoring system according to claim 1 above, characterized in that The means for detecting the geographical location comprises means (19) for receiving signals from satellites (30) of the global positioning system.

7. The state monitoring system according to claim 1 as described above, characterized in that The condition monitoring unit (10) is configured to communicate with the control unit (18) wirelessly.

8. The state monitoring system according to claim 1 above, characterized in that The means (19) for detecting the geographical location is a part of the condition monitoring unit (10) connected to the bearing unit.

9. The state monitoring system according to claim 1 described above, characterized in that The means (19) for detecting the geographical location is a part of the control unit (18) of the vehicle.

10. The state monitoring system according to claim 1 above, characterized in that The status monitoring unit (10) is configured to be connected to the wheel hub unit of a train, wherein the control unit (18) is configured to monitor the status of a plurality of wheel hub units of the train.

11. The state monitoring system according to claim 1 described above, characterized in that The control unit (18) is configured to trigger synchronous measurements through a plurality of status monitoring units (10) at a given geographical location.

12. The state monitoring system according to claim 1 described above, characterized in that The control unit (18) is configured to use the data collected by the status monitoring unit (10) for measuring track quality and use the track quality as a tool for infrastructure monitoring.

13. A state detection unit for use in a state monitoring system as described in any one of the preceding claims, characterized in that The status monitoring unit (10) includes a controller (14), and the controller (14) is configured to operate in an energy-saving sleep mode and an activation mode, wherein at least some parameters are monitored in the activation mode and not monitored in the sleep mode, and the controller (14) is configured to switch the status monitoring unit (10) from the sleep mode to the activation mode and from the activation mode to the sleep mode based on signals received by the controller (14).

14. The status monitoring unit according to claim 13, wherein the controller (14) is configured to: switch the status monitoring unit (10) from the sleep mode to the activation mode when a wake-up signal is received from the control unit (18) of the vehicle, the status monitoring system operates in the activation mode, and switch the status monitoring unit (10) from the activation mode to the sleep mode when a sleep signal is received from the control unit (18).

15. A method for monitoring the state of a vehicle bearing unit, the method using at least one condition monitoring unit (10) to measure at least one operating parameter of a bearing unit and using a control unit (18) to receive and process signals obtained by the condition monitoring unit (10), characterized in that Detect the geographical location of the vehicle and start and / or deactivate the monitoring unit (10) according to the detected geographical location, and further includes an acquisition application (24) for manually triggering measurements; The control unit (18) includes a trigger designer (22), which is configured to set trigger points for activating the status monitoring unit (10) with sensors (12); The deactivation trigger points are also set by the trigger designer (22); Wherein, the status monitoring unit (10) is started and deactivated according to the geographical location and traveling direction of the vehicle relative to the trigger point.

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