This invention relates to a module tracking system and method for tracking the history of modules of an apparatus which consists of a plurality of modules and to a module tracking device suitable for use in such a system. In particular the invention relates to a system for tracking operation of modules of an engine such as a turbine engine.

Some large or complex equipment or machinery is constructed on a modular basis and the separate modules assembled to provide the final equipment. Gas turbine engines, for example, typically comprise a number of different modules, for instance a compressor module and a turbine module etc. In such equipment different maintenance and replacement schedules may apply to the different modules and these schedules may depend on the actual usage of the equipment. There is therefore a desire to track usage of the equipment and the history of individual modules.

As used herein the term module refers to a distinct part of an apparatus which has a particular function in the apparatus and which is manufactured or maintained as a separate item. As the skilled person will appreciate a module may be a complex item and may comprise a number of different components.

US Patent No. 4,280,185 discloses a life tracking system that provides life history recording for each module of a gas turbine engine. A life tracking unit is provided for the engine and a plurality of module identifier units are mounted on associated engine modules. The module identifier units are such that they can be interrogated automatically by the life tracking unit and encode some unique identifier, such as the serial number, for each module. The life tracker unit then records appropriate usage data in memory for each module of the engine. This data can be downloaded by connecting a readout unit to the life tracker unit. The downloaded data can then be used to inform maintenance schedules. Replacement of an individual module will be detected by the life tracker unit as the new module will have a different identity to the old module.

It is an object of the present invention to provide an improved system for tracking the history of modules of a modular apparatus and to ensure that data is not lost in the event that one or more of the modules fails.

Thus according to the present invention there is provided a module tracking system for apparatus comprising a plurality of modules, said module tracking system comprising: a plurality of distinct module tracking devices, each module tracking device being associated with a different module, and an interface device for receiving operational data from an apparatus monitoring system wherein each module tracking device is arranged to receive said operational data from the interface device and to record operational data relating to usage of its associated module characterised in that each item of operational data is recorded by at least two module tracking devices.

The present invention provides a module with its own associated module tracking device for that module. This has several advantages compared to use of a single tracking device collecting operational data for all of the modules.

One advantage is that the operational data regarding usage of a module is stored in a module tracking device that it dedicated to that module. The module tracking device can remain with the module throughout its life and provide a complete history of the life of that module which can be accessed directly, i.e. without having to access some remote database. Thus, according to the present invention, an apparatus can be assembled using various modules, each with its own associated module tracking device, and the configuration and usage data for the overall apparatus can be automatically determined without requiring any external data. For instance, for some applications, modules could be taken from one apparatus, together with their module tracking devices, and used in a different apparatus and the history of the new apparatus configuration would be directly and automatically available. In the life tracking system described in US4,280,185, where there is a single life tracking unit for an apparatus, were a module of the apparatus to be replaced the history of the new module would not be automatically available. Any historic data regarding usage of the replacement module would have to be entered manually or uploaded from a device which contains the relevant usage data, such as the life tracking unit of the apparatus from which the module has been removed or a separate database containing module usage data.

Further the recording of operational data regarding usage of the modules of an apparatus in each of a plurality of module tracking devices provides automatic data redundancy in the event of failure of a module tracking device. With a single life tracker unit for the entire apparatus, such as described in US4,280,185, in the event of a memory or recording failure operational data regarding usage of all of the modules is lost. However in the system of the present invention failure of one module tracker device may result in no overall data loss. Depending on the particular apparatus, and the operational data recorded, each module tracking device may record the same data, for instance the operating parameters of the apparatus as a whole. Thus if data recoding fails in one module tracking device during use of the apparatus, the relevant data can be found in each of the other module tracking devices associated with the other modules. Also if the memory of one module tracking device fails, thus losing historic data, then the historic operational data for that module can be obtained from the other module tracking devices for at least all operation of the module in that particular apparatus configuration. If a backup of data from each module tracking module is taken every time an apparatus configuration is changed, ie at least one of the modules of the apparatus is changed, then in the event of failure of the memory of a module tracking device all data recorded prior to the last configuration change can be retrieved from the back-up and operational data recorded since the configuration change can be obtained from the module tracking devices of the other modules.

The operational data recorded by the module tracking devices will depend upon the particular apparatus and the use of the apparatus. However operational data such as temperature, operating speed/rate, efficiency, flow rate etc. may be recorded. The data may comprise data relating to the operation of the apparatus as a whole and/or to the specific operation of one or more modules of the apparatus. The overall duration of operation of the apparatus and/or relevant module(s) may be recorded as well as the duration when the operating parameters are above or below set thresholds. The skilled person will be well aware of various operational data that could be measured.

As mentioned above each module tracking device may record the same operational data as the other module tracking devices. This may be because the operational data which constitutes directly relevant usage data is the same for each module. However in some applications the relevant operational data which is useful usage data may vary from module to module. For instance a temperature of operation may be operational data which is recorded as usage data for one module but, for another module which is located in a cool part of the apparatus the temperature of operation may not be relevant. In one embodiment therefore at least one module tracking device may record a subset of the operational data, eg only that operational data which is useful usage data for its associated module. Each module tracking device may record only a subset of the operational data. However, provided that each item of operational data is recorded by more than one module tracking device there will still be data redundancy. For example, for two connected modules in a part of an apparatus that becomes hot in use both of the associated module tracking devices may record the temperature of operation. Thus in the event of failure of one of these module tracking devices the operational data regarding temperature of operation may be recovered from the other relevant module tracking device.

For data redundancy purposes the module tracking system is arranged such that each item of operational data which is recorded as usage data for a module is recorded by at least two module tracking devices. Thus, even in the case where a particular operational parameter is relevant data for only one module of the apparatus, the system is arranged to record the operational data not only in the module tracking device associated with the relevant module but also in at least one other module tracking device.

In some embodiments, where the operational data which constitutes relevant usage data is not the same for each module, each module tracking device may nevertheless be arranged to record all the operational data which is generated. This provides complete data backup in the module tracking system itself. Further, although some of the operational data may not be relevant to a life usage calculation for a module it may nevertheless be of interest for general analysis of the history of the module. Depending on the amount of operational data recorded it may not be practical to store all such operational data indefinitely. Therefore any operational data which is stored in a module tracking device which is not directly relevant to usage of its associated module, i.e. required to perform a life usage calculation, may be periodically deleted, for instance after such operational data has been downloaded to a backup system. The data storage capability of the module tracking devices is preferably such as to be able to store all the operational data which is generated in the life of that module which is directly relevant to module usage. Thus all operational data which is directly relevant to that module may be maintained in the associated module tracking device for the lifetime of the module but data which is stored for redundancy purposes may be periodically deleted to free memory space.

The interface device communicates with the apparatus monitoring system and provides relevant operational data to each of the module tracking devices. One of the module tracking devices maybe arranged to function as the interface device and to receive operational data from the apparatus monitoring system and communicate it to the other module tracking devices. However in some embodiments a separate interface device is provided as part of the module tracking system. Such a separate interface device may have its own data store and may store at least some operational data for data redundancy purposes. The interface device may also process the data received from the apparatus monitoring system into a form which is useful operational data relevant to usage of the modules.

The apparatus may include more than one apparatus monitoring system. The interface device may interface with each apparatus monitoring system or there may be more than one interface device, each interface device receiving operational data from one or more apparatus monitoring systems and communicating such operational data to the module monitoring devices.

The operational data may comprise data which is measured in normal performance of the apparatus, i.e. monitored for automatic control or health monitoring of the apparatus in use. In this case the interface device of the module tracking system may be arranged to receive data from a monitoring system of the apparatus which comprises part of a control or health monitoring system of the apparatus. For example, turbine engines have an engine controller which connects to various sensors and monitoring devices. The module tracking system of the present invention therefore interfaces with the engine controller to determine the operational parameters of the engine.

The operational data may additionally or alternatively comprise data which is measured purely for tracking usage of modules to allow life usage calculations to be performed and which is not otherwise monitored in use of the apparatus. In such case the module tracking system may itself comprise at least one apparatus monitoring system comprising various sensors for monitoring operation of the apparatus.

In some applications the amount of information that is monitored in use may vary between different apparatuses that a module may be used in. For instance older installations of apparatus may record different or less operational data than newer installations. A particular module may be compatible with both the older and the newer installations and may, in its life, be used in either or both. The module tracking device is therefore preferably adapted to record whatever operational data is available. The module tracking devices record appropriate operational data for the associated module during its life. The module tracking devices may also store other data about the associated module. The module tracking device may store data regarding the module identity, serial number and part number. Information such build records and pass-off certificates or other certificates of quality may be stored. Technical data regarding the module such as drawings, installation and servicing notes, repair manuals etc. may also be stored in the module tracking device along with data on the release life of the module. Data regarding the set ^: up or configuration of the module may be stored in the module tracking device. Some additional data may be uploaded to the module tracking device when it is associated with a particular module. Other data will be added during the life of the module, for instance the data may be updated as part of the maintenance and repair of the module to add servicing notes or indicate changed settings etc. The data may also include data regarding who to contact for advice or assistance with module servicing, repair or installation and information regarding replacement parts.

Providing data regarding the complete history of the module allows all necessary records to maintained with the module itself throughout its life. This will greatly aid in assessing use of the relevant module and aid in servicing and repair. Providing the relevant repair and servicing instructions means that service engineers do not need to take the associated documentation with them when visiting the site of the module. This improves flexibility and the engineer may not need advance notice regarding what modules are to be serviced or repaired. Providing contact details for assistance further enables engineers to deal with any problems they encounter without prior warning. This may reduce the need for call out of specialist engineers.

A module tracking device may be fitted to a module which is already in service and thus has an existing usage history. In such a case information regarding the previous operational data may be available in various forms depending on the records available regarding previous usage. It may be possible to obtain all such relevant historic usage data and add this data to the module tracking device. However obtaining and uploading all available historic data may take significant time. Thus for existing modules all data readily available, for example part and serial number, any settings data and the condition of the module at the last overhaul may be stored in the module tracking device along with details regarding where records about any previous usage are stored and how to access the data. Thus a route to obtaining the historic data regarding usage prior to fitting of the module tracking device may be provided. A rough estimate of previous usage or remaining life may be included in the module tracking device and/or any life usage algorithm may be adjusted to account for the previous usage and the accuracy to which it is known. Whilst the module tracking device for such a module with previous use may therefore not provide a complete usage history it will track all future usage and provides, where possible, an indication of what additional historic information is available and where to obtain such information and thus still represents an improved store of information.

Where the module tracking device stores data regarding the settings of the module and the interface device of the module tracking system is connected to a control system of the apparatus the setting information of one or more modules may be automatically supplied to the control system of the apparatus on assembly or commissioning of the apparatus.

Upload and/or download of data to/from a module tracking device or the module tracking system may require some sort of security verification, for instance password protected access or the like. Access to some data or performance of some actions may require a different level of verification, for instance service personnel of the module manufacturer may have different set of permissions to service personnel or the module operator or third party personnel. As an example operational data may be freely downloadable without verification but deleting data held in a module tracking unit which is held for redundancy purposes may require a password or access code - which may only be provided by a central database when a back-up has been successfully completed. Sensitive data such as module settings may be protected so as to prevent accidental changes from being made or to allow changes to be made by only certain classes of personnel. Some data regarding the specifications or servicing of the module may be commercially sensitive and thus may be protected so that it can only be accessed by authorised engineers. The identify of the author of changes to the stored data may be recorded by the module tracking device.

When a new module is added to an apparatus, whether as part of a new build of an apparatus or replacement of an individual module, the module tracking system may be arranged to ensure that all data in each module tracking device is duplicated in at least one other module tracking device. This ensures that all data regarding a module is available in the event of a failure of its associated module tracking device. As mentioned above, a back-up of the data from all modules is preferably made each time the configuration of the apparatus is changed and thus, in the event of failure, full data recovery can be made with access to the backup. However ensuring that all data is duplicated in other module tracking devices means that data recovery can be made using the module tracking system alone without requiring access to a remote database.

Copying historic module data for data redundancy purposes does however require a relatively large data storage capability. Therefore it may be preferred not to duplicate all data and instead to rely on the back-up of data taken when an apparatus configuration is changed. However any data added to any of the devices of the module tracking system between back-ups may be duplicated for data redundancy purposes. This will include any operational data relating to usage of the apparatus and the modules and may also include any updates or additions to any other data stored for a particular module. For instance if an updated repair manual or new service guide is released for a particular module it will be necessary to update the data held the appropriate module tracking device. If the relevant module is part of an apparatus configuration it may be wished to update the module tracking device in situ. Thus new or updated information relevant for a module may be uploaded to a module tracking device which is part of an apparatus configuration. The data may be uploaded directly to the relevant module tracking device if conveniently accessible or it may be uploaded via another device of the module tracking system such as another module tracking device or the interface device. Such updated data, however supplied, may be duplicated in the module tracking system for data redundancy purposes until the next complete back-up of data is taken. Thus if the relevant module tracking device fails the back-up data will contain all data which was relevant at the time that the back-up was acquired. Operational data regarding usage of the apparatus since the time of the back-up and any other updated data, such as an updated repair manual for instance, can be obtained from the other devices of the module tracking system. This arrangement provides an acceptable balance of convenience, data security and storage requirements.

The module tracking system conveniently include a means of determining the life usage of the modules based on the stored operational data. There may be a single life usage calculator located in the module tracking system for receiving data from the modules and determining life usage. The results of the calculation can be stored in the relevant module tracking device. In another embodiment however each module tracking device may have a means for determining life usage for its associated module based on the stored operational data. The life usage may include a figure representing the total usage of the module over its lifetime and/or since it last underwent maintenance or repair. The life usage may indicate the remaining life of the module before maintenance and/or replacement is necessary. The module tracking device may therefore comprise a processor for performing at least one life usage calculation based on the stored operational data. The module tracking device may apply one or more stored life usage algorithms to determine the life usage for the module based on the available operational data.

Preferably there may be a separate module tracking device associated with each module which it is desired to track. In some embodiments each separate module of the apparatus may have a separate module tracking device associated with it. However in some embodiments some modules that form part of the apparatus may not require tracking. For instance if two distinct modules that form part of an apparatus must always be replaced at the same time and can't be reused or separately refurbished it may be sufficient to use just one module tracking device associated with one of the modules. Similarly if one or more modules of the apparatus do not have a maintenance schedule based on usage there may be no need to monitor usage thereof. However it should be noted that the present invention is not restricted to monitoring usage for the purposes of deciding maintenance schedules. Operational data regarding usage of modules may be tracked and analysed for a variety of purposes, for instance overall apparatus performance against module usage could be analysed or module usage could be analysed in failure analysis.

At least one module tracking device may be mounted on or within its associated module. This arrangement helps ensure that the module tracking device always stays with the associated module. However for some modules it may not be practical to mount the module tracking device directly on or within the module. For instance if the module experiences harsh operating conditions in use, such as very high or very low temperature, it may be more convenient to locate the module tracking device in another part of the device than to provide a protective environment or a sufficiently ruggedized module tracking device. Preferably however each module tracking device is physically attached to its associated module. This may be achieved be directly mounting the module tracking device on or within the module as describe above or, where such direct mounting is not possible, by use of a suitable connector, for instance a connecting wire or chain. This means that the module can not be easily moved without its associated module tracking device and also provides a physical indication of which module tracking device is associated with which module.

Each module tracking device is arranged to receive operational data from the interface device. Each module tracking device may receive operational data directly from the interface device or at least some of the module tracking devices may receive data from the interface device via at least one other module tracking device.

Conveniently the module tracking devices in an apparatus are operably connected for serial data transfer in a chain type arrangement where data can be passed along the chain and at least one module tracking device is linked to the interface device. Adjacent module tracking devices in the chain may be linked with a serial data bus. It will be clear however that other data connection arrangements are possible. For instance one module tracking device could act as a hub for at least some of the other module tracking devices.

The module tracking system in one embodiment may further comprise at least one configuration tracking device arranged to communicate with each of the module tracking devices. The configuration tracking device is capable of communicating with the module tracking devices to determine the current apparatus configuration. The configuration tracking device is conveniently associated with a permanent part of the apparatus structure. The configuration tracking device can provide a unified view of the current apparatus configuration and the history of the current configuration and usage of the modules of the apparatus. The configuration tracking device may have its own data store for recording data regarding the current configuration of the apparatus and the identity and usage of the modules forming the apparatus. This data store may also be used to duplicate data held elsewhere in the system, for instance in a module tracking device, for data redundancy.

The configuration tracking device is preferably associated with the apparatus whereas the individual module tracking devices are associated with individual modules. When a module is replaced the configuration tracking device will communicate with the module tracking device of the replacement module and automatically provide an updated configuration. The configuration tracking device may conveniently comprise the interface device and thus provide the interface with the apparatus monitoring systems.

The configuration tracking device may be located in the apparatus in a location offering relatively ease of access in the assembled apparatus. The configuration tracking device is conveniently provided with an input/output port for upload/download of data, either to the configuration tracking device itself or any one or more of the module tracking devices. Thus, in the assembled apparatus, the configuration tracking device allows easy data transfer to or from the whole module tracking system of a particular apparatus, avoiding the need to access each module tracking device separately.

Updated data which is uploaded to a particular module tracking device, such as an updated service manual or updated life usage algorithm, may therefore be uploaded via the configuration tracking device. The configuration tracking device ensures that the data is supplied to the relevant module tracking device and also ensures that any data uploaded between system back-ups is duplicated for data redundancy.

The configuration tracking device may also be provided with a visible display for displaying the current apparatus configuration and/or the related usage information, i.e. the usage data of one or more modules and/or the calculated life usage of one or more modules. Additionally or alternatively the module tracking system may communicate the usage data and any calculated life usage for the modules to the apparatus control system for display on a general control display associated with the apparatus.

The module tracking system for a particular apparatus may be integrated into a larger tracking system. Thus a module tracking system for an apparatus may also be arranged to communicate with or be part of a larger module tracking system. For example if a turbine engine is used as part of a the drive train of some industrial equipment or a vehicle a tracking system may be provided for all the apparatus of the drive train. Thus the module tracking system may be arranged with some module tracking devices being provided on different modules of equipment. In one embodiment the module tracking system of a particular modular apparatus may, in effect act as a single apparatus tracking device and be linked with other apparatus tracking devices in an apparatus tracking system, ie taking the drive train example the turbine engine is provided with a module tracking system for tracking the usage of modules and the current configuration of the turbine engine. This module tracking system also acts as a single apparatus tracking device and communicates with other apparatus tracking devices associated with the other pieces of apparatus forming the drive train. The overall apparatus tracking system may operate in the same way for the whole drive train as the module tracking system does for the turbine engine.

A module tracking device suitable for use in the present invention preferably comprises a data store, a communication unit for communicating with at least one other module tracking device and/or the interface device and a local data input/output port. The data store, which may be any suitable memory, stores operational data and any other data relating to the module. The communication unit controls the transfer of data over a suitable communication link such as a data bus and passes relevant operational data to the data store. The local data input/output port allows data to be uploaded/downloaded through direct connection to the module tracking device which is useful for when the module tracking device is not connected as part of a module tracking system. The module tracking device may also comprise a life usage calculator for determining life usage figures based on the stored operational data.

As mentioned above one of the features of the module tracking system of the present invention is that each module which it is wished to track is provided with its own dedicated module tracking system. Thus in another aspect of the invention there is provided a module of a modular apparatus comprising a module tracking device attached to the module, the module tracking device comprising a communication unit for receiving operational data relating to usage of the module, a data store for storing said operational data relating to usage of said module and a life usage calculator for determining the life usage of the associated module based on the stored operational data.

The module tracking device, in use in an assembled apparatus, forms part of the module tracking system described above and all of the features and embodiments described above apply to this aspect of the invention.

In particular the life usage calculator is conveniently a suitable processing means for determining life usage based on the stored operational data in accordance with one or more stored algorithms. As described above the life usage may include a figure relating to total usage of the module and/or remaining life of the module before maintenance or replacement is due.

The present invention also relates to a module tracking device itself and thus, according to another aspect of the invention there is provided a module tracking device for tracking usage of a module in an apparatus, said module tracking device comprising a communication unit for receiving operational data relating to usage of the module, a data store for storing said operational data relating to usage of said module and a life usage calculator for determining the life usage of the associated module based on the stored operational data

The invention also relates to a method of tracking the history of modules of modular apparatus and to a method of using a module tracking system as described above. Thus according to another aspect of the invention there is provided a method of tracking the history of modules of an apparatus comprising the steps of: providing each module which is to be tracked with a module tracking device; monitoring, via a monitoring system, the usage of the apparatus and/or the modules; communicating operational data from the monitoring system to each of the module tracking devices; and recording in each module tracking device operational data relating to usage of at least two of the associated modules. The method of the present invention benefits from all the advantageous described above in relation to the first aspect of the invention. The method of the present invention may use the module tracking system as described above and any of the embodiments described above may be used in the method of the present invention.

In particular the method involves storing each item of operational data in more than one module tracking device to provide data redundancy. The method may also comprise the step of, in the event of failure of a module tracking device associated with a module, providing a replacement module tracking device for that module and loading the replacement module tracking device with historic operational data for that module and from at least one other module of the apparatus. As described above the method of the present invention allows full data recovery in the event of failure of an individual module tracking device.

The step of providing a module with a module tracking device may comprise physically attaching the module tracking device to the module, for instance by mounting the module tracking device on or within the module or attaching it via a connector. The step of providing a module with a module tracking device may also comprise loading the module tracking device with additional data regarding the module, the additional data being at least one of: the identity of the module; technical data regarding the module; the release life of the module; the configuration of the module. Contact details for assistance regarding the module may be also be provided. As described above the module tracking device may comprise a complete history of the relevant module.

The method may involve modules which are newly fabricated being provided with module tracking devices. The method may also involve providing a module with previous usage with a module tracking device. In this case the method may involve loading the historic data regarding previous usage of the module into the associated module tracking device. In some instances however it may be not possible or practical to provide operational data regarding previous usage of the module. In such a case the method may involve including in the module tracking device data about where any information regarding previous usage of the module may be obtained. The method may include providing an estimated previous usage or adjusting the remaining life of the module, or a life usage algorithm used by the module tracking device, to account for the previous usage of the module and the accuracy to which such previous usage is known.

Where the additional data comprises data regarding the configuration of the module and the method may comprise the step of communicating the data regarding the configuration of the module to a control system of the apparatus. This allows the control system to be automatically responsive to a new apparatus configuration.

The method may involve the step of arranging each module tracking device to perform a life usage calculation for its associated module based on the recorded operational data and a stored life usage algorithm. The life usage calculation may calculate total usage of the appropriate module or usage of the module in relation to certain operating modes, for instance duration of use above a certain speed or temperature. The life usage calculation may additionally or alternatively calculate remaining life before maintenance or replacement of the module is required. Each module tracking device may communicate the results of the life calculation to a configuration tracking device associated with the apparatus. The configuration tracking device may display information regarding the results of the life usage calculation on a display and/or may pass the results to an apparatus control system.

The method may involve periodically taking a copy of the data held in a module tracking device. For instance the method may involve taking a copy of the data held in the module tracking devices of an apparatus every time at least one of the modules in the apparatus is changed. This data can be held in one or more databases as backup data. The method may involve updating the data held in a module tracking module every time a module is repaired or maintained to include data relating to the maintenance or repair performed.

The method may involve the step of, following replacement of at least one module of the apparatus, performing an initialisation step to ensure all data held in each module tracking device is also recorded in at least one other place. The data may be duplicated in another module tracking device and/or an interface device or configuration tracking device of the module tracking system.

The invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 illustrates a schematic of one embodiment of the module tracking system of the present invention;

Figure 2 shows a schematic of a module tracking device according to the present invention.

The invention will be described in relation to a gas turbine engine formed from a plurality of modules. However it will be appreciated that invention is applicable to other equipment or machinery which is assembled from a number of modules, which can be independently replaced, wherein the usage and life history of modules may advantageously be tracked.

Figure 1 illustrates a gas turbine 1 which, in this instance, consists of five separate modules 2a - 2e. The skilled person will appreciate that the arrangement shown in Figure 1 is shown for illustrative purposes only and does not necessarily represent the arrangement of modules in an actual engine. The modules which form part of a gas turbine will be well known to one skilled in the art and, for instance, may include a turbine module, a compressor module etc. Each of these modules can be replaced independently of the others. A new engine will normally be assembled from new modules, each of which will have a different release life. Under normal circumstances the engine will be overhauled several times during its operational life and on some of these occasions modules will be replaced with either new units or serviced exchange units. The present invention provides a system and method for tracking individual modules so that a complete life history of the module is always available and so that calculations regarding the usage of the module and/or the remaining life of the module can be performed.

Each module 2a - 2e is attached to an associated module tracking device 3a - 3e. As shown in Figure 1 , module tracking device 3a is directly attached to module 2a. The module tracking device may mounted on, or within, any convenient part of the module where it will not interfere with the operation or fitting of the module in use. Similarly module tracking devices 3b and 3c are directly attached to their associated modules 2b and 2c.

Module tracking devices 3d and 3e are not located on or within the associated modules 2d and 2e as these modules experience harsh operating conditions in use. For instance the modules 2d and 2e may become very hot in use. Whilst it may be possible to mount the module tracking devices 2d and 2e on the modules in suitably insulated and/or cooled packages it may be more convenient to locate the module tracking devices 2d and 2e in a part of the apparatus where no special packaging is required. The module tracking devices could be located elsewhere on the apparatus or a support for the apparatus and could be located on one of the modules 2a - 2c. Module tracking devices 2d and 3e are however connected to their associated modules 2d and 2e by connectors 4. The connectors 4 may be any suitable connector such metal wires or chains that can withstand the operating temperatures and are provided such that a module tracking device can not easily be separated from its associated module during maintenance or overhaul of the engine. The connectors 4 also serve as a visible indicator of which module tracking device is associated with which module. Clearly the connectors 4 are arranged in use so as not to interfere with the operation or maintenance of the engine.

The module tracking devices 3a - 3e are serially connected to one another by data buses 5 in a chain arrangement. As illustrated each module tracking device 3a - 3e has two serial data links, one for exchanging data with the previous link in the chain and one for exchanging data with the subsequent link in the chain although it will be appreciated that other communication arrangements are possible. The skilled person will be aware of suitable data buses that can be used for data transfer in the environment of an operating gas turbine.

Each module tracking device 3a -3e also has a local data input/output port 6 to for direct connection to a data reading and/or writing equipment. This allows data to be downloaded/uploaded directly to/from the module tracking device in accordance with security/authentication protocols. Conveniently the module tracking devices 3a - 3c, which are located on their associated modules, are located somewhere which offers relatively easy access to the module tracking device, or at least the local data port 6 of the module tracking module, when the module is removed from the apparatus. The local data port 6 may therefore be connected to the main body of the module tracking device by suitable data cable, allowing the data port to be located in a more accessible position than the main body of the module tracking device.

An identity module 7 is also serially connected to the module tracking devices by data buses 5. Together the identity module 7 and the module tracking devices 3a - 3e are linked by data buses 5 in a ring network. Communications may be arranged to flow in one direction around the ring and the buses 5 may be unidirectional buses. Preferably however data may flow in both directions and the data buses are bidirectional buses so that failure of any one data link does not prevent data transfer. The identity module is preferably located in a more permanent part of the apparatus or apparatus support as the identify module will remain in situ for the life of the apparatus. The purpose of the identity module is to track the configuration and usage of the whole apparatus. The identity module therefore comprises a configuration tracker 8 which communicates with each of the module tracking devices to determine the identity of the modules that form part of the apparatus and the results of the life usage calculations performed by each of the module tracking devices as will be described later. The data regarding the current apparatus configuration is stored in the configuration tracker.

The identity module also comprises an interface device 9 which acts as a portal for accessing operational data for the apparatus. The way in which this is configured will be application dependent.

The identity module may communicate with a control/health monitoring system 10 of the apparatus. The control/health monitoring system 10 may include a plurality of sensors 11 for monitoring the operating parameters of the various modules and the apparatus as a whole.

In new apparatus designs the module tracking system may be an integral part of the control and health monitoring systems of the apparatus and the identity module 7 may be provided as part of the apparatus control/health monitoring system 10.

Where the module tracking system is integral with an engine control system it will enable module data to be read directly by the engine controller during engine commissioning. This will allow data, such as trim settings etc., which are stored in a module tracking device to be directly uploaded into the controller without the need for manual intervention.

For some older engine designs a health monitoring system may have been retrofitted to the engine and the module tracking system may be linked to receive data from such a health monitoring system. Where the module tracking system is implemented separately from the engine controller, for instance where it is fitted to an existing design, additional sensors may be required to gather the operational data. This is shown in Figure 1 where an additional sensor 12 is provided on module 2d. The additional sensor 12 is arranged to communicate with the module tracking device 3d associated with module 2d, although it could be arranged to communicate with any of the other module tracking devices or directly with the identity module. Module tracking device 3d communicates the data received from the additional sensor 11 to the other module tracking devices.

The identity module 7 has a display 13 for displaying data regarding the current configuration of apparatus, the usage data or results of the life usage calculations in respect of the modules and/or any warnings regarding modules that need attention. Additionally or alternatively this data may be communicated to the control/health monitoring system 10 and displayed on a display 14 of the control/health monitoring system 10.

The identity module has a local data port 6 for allowing data download or upload from or to the identity module or any or all of the modules in the module tracking system. The identity module can therefore allow ease of access to the data stored in the whole system.

A module tracking device according to one aspect of the invention is shown schematically in Figure 2. The device has a communication component 20 for receiving data from and transferring data to each of the two serial data links. The communication component also controls data exchange via the local data port 6.

The module tracking device has a processor 22 connected to a data store 23. The processor may be any suitable device for performing the required processing, it may comprise a dedicated logic circuit or a suitably programmed FPGA or the like or could comprise a suitably programmed microprocessor. Preferably the processor is programmable so that the processing performed may be changed in use, for instance where the algorithms for performing life usage calculations are updated in use. The data store may be any suitable memory which is capable of storing the required data.

The processor may process operational data received to determine whether such data needs to be stored in the data store. The processor may for instance store only a subset of all data received as not all data may be relevant for the associated module. The processor may perform some processing to reduce data storage requirements. For instance individual temperature readings may be initially stored and subsequently processed to record only the duration at which the temperature was above a certain threshold.

The processor is also arranged to apply one or more life usage algorithms to the stored data to determine life usage figures. These figures may indicate the usage history of the module and/or may determine the usage left before the module needs maintenance or replacement. The skilled person will be aware of various life usage calculations that may be performed.

To illustrate how the invention will be used the various stages in the life of a typical module will be described.

New Module

A new module will be assembled with a new module tracking device attached to it. Depending on the type of module the module tracking device may be located on or within the module or connected via a connector as described above. The module tracking device will be supplied with the basic operating software pre-installed and during the build and test process it will be programmed with all the information that is relevant to the module. The loaded data will include the module identity, part number, release life, trim settings, drawings, installation notes, concession notes and any other data deemed to be useful such as contact details for help or assistance with the module.

It will also be loaded with any module specific programs that the unit will be required to run, such as the life usage calculation.

When the equipment module is fully completed and the module tracking device is fully programmed, a copy of the complete software and data installed in the device is downloaded to secure storage. A copy of this software and data may be sent to and stored in a central database.

New module is installed

The module is assembled into the equipment and prior to operation the equipment will be commissioned. As part of this process the module tracking system will be set to work.

The commissioning engineer will power the module tracking devices and check that each of the devices is operating correctly. The commissioning engineer will take with him copies of the programming of each of the modules and some spare module tracking devices, so that, for example, a transit damaged device may be replaced.

The next stage is to initialise the module tracking system. This is an automatic process that will be controlled by a program, most likely to be resident within the Identity Module.

This initialisation will load the Identity Module with relevant data from all the module tracking devices and also supervise the distributing of data held in each of the module tracking devices to multiple storage locations within the module tracking system. Where the module tracking system has been designed to integrate fully with the equipment control system it will be possible to upload all the trim setting directly to the engine control system.

When the module tracking system has been fully commissioned, the commissioning engineer will take copies of all the data held within each of the module tracking device and the Identity Module. This is the Baseline Installation Data. One copy of the Baseline Installation data will be retained with the equipment and a second copy will be sent to the central database for archiving.

Normal Operation of the Engine

During use of the engine the interface device within the identity module obtains the operational data on use of the engine. This operational data is supplied to each of module tracking device where the data is stored in such a way that each item of operational data is stored in at least two places in the module tracking system. Conveniently each of the module tracking devices stores all of the operational data.

Each of the module tracking devices continually or periodically uses the stored operational data and one or more life usage calculations based on the release life of the module to determine life usage. The results, which may indicate the remaining life before replacement or maintenance is necessary may be provided to the Identity Module for display.

An equipment module is exchanged

During the life of the equipment it is expected that some of the equipment modules will need to be replaced. Prior to removing the module to be replaced, the service engineer will take a copy of all the data from the module tracking devices and the identity module. This is a precaution in case any of the module tracking devices or the identity module becomes damaged during the equipment module exchange. The module is then exchanged. The module tracking system is then initialised, in the same way as for a new installation. Copies of data from the module tracking devices will form the Baseline Installation Data for the new equipment configuration. One copy of the Baseline Installation data will be retained with the equipment and a second copy will be sent to the central database for archiving.

Where appropriate the service engineer will issue a report concerning the reasons for the removal and outlining possible issues with the module. A copy of this report will be loaded into the module tracking device for that module.

An equipment module is refurbished

When a module is returned for repair or a rebuild, a copy is taken of the data held within its module tracking device. The service history, usage information and current modification status of the equipment module are all stored in the module tracking device and may be used to identify the remedial work required.

Once the equipment module has been rebuilt and fully tested the module tracking device will be updated by adding details of the work carried out, amending trim parameters and adjusting the release life, as appropriate.

When the equipment module is fully completed and the module tracking device is fully programmed, a copy of the complete software and data installed in the module tracking device is downloaded to secure storage. A copy of this software will be sent to and stored by the central database. The module is then ready to be re-installed in an apparatus. A module tracking device becomes faulty in service

In the event that one of the module tracking device fails in service there is no requirement to immediately replace the unit as it is possible to rebuild all the information contained within the unit at the point at which it ceased to work. It is also possible to update the operational information to bring it fully up to date.

During the initialisation of the Module Tracking System all the information retained within the module tracking device, is copied into multiple storage locations within the system. The new replacement module tracking device will be supplied with the basic operating software pre-installed. A restore program will be used to reinstate the baseline information; the data that was copied from the unit at the point the module became part of the equipment as a whole. Depending on the amount of data that is stored within the module tracking devices it may better not to distribute the storage of all the baseline data and use a copy of the stored baseline data to rebuild this part of the information. This restores the data contained within the module tracking device to the baseline state. The operational information for the relevant module will be the same as for the other modules and a second restore program will enable this data to be retrieved from other locations within the module tracking system and trigger the calculation of the life usage up to the present time.

In order to ensure that the latest data is always present it is important that when additional information is added to any of the module tracking devices that a minor initialisation program is run to ensure that the data is distributed around the system properly. Algorithm changes to life calculation or similar

It is likely that during the life of the equipment advances may be made allowing better assessment of module life to be made. This is easily accommodated because at any stage the way in which the module tracking device works can be modified. The module tracking device data should be stored as a baseline, whenever a new algorithm is introduced.

If any data is added to a module tracking device in use and a copy of the updated data is not taken as a Baseline back-up the module tracking system is arranged to duplicate the new or updated data within the module tracking system. Thus there is always data redundancy of all data stored in any module tracking device.

Some equipments do not have the same information available

During its life a module may be used several equipments. The information available to calculate life may be different from equipment to equipment. This does not present any problem because the module tracking devices will be programmed such that they determine the usage as accurately as possible based on the information available. The algorithm used and the equipment configuration is stored within the module tracking device, enabling life extension or reductions to be considered in the future, in the event that a better understanding of the life usage becomes available.

Fitting a module tracking device to an existing module

Engine modules already in service will have a history and for several applications data regarding previous usage may be available from various sources. However obtaining all this historical data and loading it into a module tracking unit may take an unreasonable amount of time. An existing module can therefore be treated as if it is a new module and thus loaded with the data described above regarding module identity, part number, release life, trim settings, drawings, installation notes, concession notes etc. Further, information regarding the condition of the module at the last overhaul and usage since the last overhaul will be added along with current service reports and bulletins to give an indication of the current condition of the module. A route to obtain further information regarding the past history of the module is also included, for instance contact details of relevant personnel.

Once the module has been associated with a suitably programmed module tracking device it can be used as described above. The life usage calculator of the module tracking device may however be adjusted to account for the unrecorded past usage of the module.

The present invention therefore provides a flexible and efficient system and method of tracking the history of modules of an apparatus wherein a data regarding the history of the module remains with the module throughout its life. The system includes data redundancy and thus minimises the chance of data loss in use. Further each module is provided with a means for calculation of life usage of that module without requiring any external data.