TECHNICAL FIELD

The present invention relates to a control system for an engine such as a die- sel engine, a gas engine or a liquid natural gas (LNG) engine, where the control system is equipped with a safety control means that may be employed e.g. to ensure safety of the maintenance personnel during maintenance operations applied to the engine.

BACKGROUND

Engines of several types, such as internal combustion engines (ICE) like diesel engines, gas engines and LNG engines, are commonly used for various industrial purposes to supply power e.g. in power plants, in marine vessels, in offshore platforms such as oil rigs, etc. In this regard, a single engine or an engine system of a plurality (e.g. two or more) engines may be employed as the power source. In such use of one or more engines, a high operational reliability and early reaction to any need for maintenance of an engine is typically a critical characteristic for the performance of the engine or engine system, while any maintenance operation to be carried out for an engine preferably requires as short downtime of the engine as possible to limit the interruptions or reduc- tions in the power supply from the engine or engine system.

On the other hand, a maintenance operation performed on a large engine typically employed in such usage scenarios requires special attention to the safety of the maintenance personnel. As a particular example, there is typically a need to ensure that the engine is not accidentally started during a mainte- nance operation for safety reasons, which in known solutions is typically provided via a mechanical or electro-mechanical switch provided for the purpose of switching off the power from the engine. However, in many occasions this may lead to a cumbersome and/or unsatisfactory solution that may result in prolonged or sometimes even unnecessary downtime of the engine in view of the characteristics of the maintenance operation in question. SUMMARY

Therefore, it is an object of the present invention to provide a technique for ensuring safety during maintenance of an engine in a flexible manner.

The object(s) of the invention are reached by an apparatus, by a method and by a computer program as defined by the respective independent claims.

According to an example embodiment, an engine control system for controlling user access to one or more engine control functions is provided, where the engine control system is communicatively coupled to an engine via an engine control interface and where the engine control system comprises one or more human-machine interface, HMI, units, each HMI unit comprising a respective user interface, Ul, for providing user access to respective one or more engine control functions, wherein at least one HMI unit comprises a respective lock means for receiving a safety key that represents a key identification, ID, which key ID has at least one engine control function associated therewith, wherein the engine control system is arranged to, when the lock means in a first HMI unit is in receipt of the safety key that represents a first key ID, selectively provide via the Ul of said first HMI unit one of the following: a locking function for locking, by the first key ID, said at least one engine control functions associated with the first key ID to disable user access, via said Uls, to said at least one engine control function or an unlocking function for releasing said at least one engine control function from locking by the first key ID to re-enable user access, via said Uls, to those ones of said at least one engine control function that are not locked by one or more other key IDs.

According to another example embodiment, an engine control arrangement is provided, the engine control arrangement comprising one or more engine control systems according to the example embodiment described in the foregoing and a local central control unit, LCCU, communicatively coupled to said one or more engine control systems, wherein the LCCU comprises a Ul for providing user access to one or more engine control functions in said one or more en- gine control systems and further comprises at least one lock means for receiv- ing a safety key that represents a key ID, which key ID has at least one engine control function associated therewith, and wherein the engine control arrangement is configured to, when the lock means in the LCCU is in receipt of the safety key that represents a first key ID, selectively provide via the Ul of the LCCU one of the following: a locking function for locking, by the first key ID, the at least one engine control function associated with the first key ID to disable user access, via all Uls in the engine control arrangement, to said at least one engine control function or an unlocking function for releasing the at least engine control function from locking by the first key ID to re-enable user access, via all Uls in the engine control arrangement, to those ones of said at least one engine control function that are not locked by one or more other key IDs.

According to another example embodiment, a method for controlling user access to one or more engine control functions in an engine control system that is communicatively coupled to an engine via an engine control interface is pro- vided, the method comprising operating one or more HMI units, each HMI unit comprising a respective Ul for providing user access to respective one or more engine control functions, wherein at least one HMI unit comprises a respective lock means for receiving a safety key that represents a key ID which key ID has at least one engine control function associated therewith, and selectively providing, via the Ul of a first HMI unit, when the lock means in the first HMI unit is in receipt of the safety key that represents a first key ID, one of the following: a locking function for locking, by the first key ID, said at least one engine control function associated with the first key ID to disable user access, via said Uls, to said at least one engine control function or an unlocking function for releasing said at least one engine control function from locking by the first key ID to re-enable user access, via said Uls, to those ones of said at least one engine control function that are not locked by one or more other key IDs.

According to another example embodiment, a computer program is provided, the computer program comprising computer readable program code configured to cause performing at least the method according to the example embodiment described in the foregoing when said program code is executed on one or more computing apparatuses.

The computer program referred to above may be embodied on a volatile or a non-volatile computer-readable record medium, for example as a computer program product comprising at least one computer readable non-transitory medium having program code stored thereon, the program which when executed by an apparatus cause the apparatus at least to perform the operations described hereinbefore for the computer program according to an example embodiment of the invention. The exemplifying embodiments of the invention presented in this patent application are not to be interpreted to pose limitations to the applicability of the appended claims. The verb "to comprise" and its derivatives are used in this patent application as an open limitation that does not exclude the existence of also unrecited features. The features described hereinafter are mutually freely combinable unless explicitly stated otherwise.

Some features of the invention are set forth in the appended claims. Aspects of the invention, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of some example embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF FIGURES

The embodiments of the invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings, where

Figure 1 illustrates a block diagram of some components of an engine control system according to an example embodiment;

Figure 2 schematically illustrates a user interface (Ul) of a human-machine interface (HMI) unit according to an example embodiment; Figure 3A schematically illustrates some aspects of a Ul of a HMI unit according an example embodiment;

Figure 3B schematically illustrates some aspects of a Ul of a HMI unit according an example embodiment; Figure 4 illustrates a block diagram of some components of an engine control system according to an example embodiment;

Figure 5 illustrates a block diagram of some components of an engine control arrangement according to an example embodiment;

Figure 6 illustrates a flowchart depicting a method according to an example embodiment; and

Figure 7 schematically illustrates some components of an exemplifying apparatus for providing the diagnostics system according to an example embodiment.

DESCRIPTION OF SOME EMBODIMENTS Figure 1 illustrates a block diagram of some components of an engine control system 100 according to an example. The engine control system 100 is illustrated with local human-machine interface (HMI) units 1 10-1 , 1 10-2, 1 10-K. Each HMI unit 1 10-k comprises a user interface (Ul) that provides user access to one or more engine control functions for controlling operation of an engine 102. Each of the HMI units 1 10-k is communicatively coupled to an engine control interface (ECl) 101 for transfer of engine control information and engine status information therebetween.

The ECl 101 is coupled to an engine 102 and it serves to convert the engine control information received from the HMI units 1 10 to respective control ac- tions for controlling the engine 102 (e.g. by using respective drivers or actuators provided as part of the ECl 101 ) and to convert the engine status information (obtained e.g. by using respective sensors provided as part of the ECl 101 ) in format suitable for provision to the HMI units 1 10. The ECl 101 may be provided by hardware or as a combination of hardware and software. The engine 102 may be, for example, an internal combustion engine such as a diesel engine, a gas engine or a LNG engine, and the engine 102 may be a standalone engine or the engine 102 may operate as part of an engine system of a plurality (e.g. two or more) engines. The details of operation of the ECl 101 and/or the engine 102, however, are not directly relevant to embodiments of the present invention but they are outlined here to illustrate the relationship between the engine 102 and the engine control system 100.

The HMI units 1 10-1 , 1 10-2, 1 10-k illustrated in Figure 1 represent one or more HMI units 1 10 and for a given engine the number of HMI units 1 10 may be one, two, three, etc., depending on the physical size of the engine 102 in view of the desired 'ease' of accessing the HMI units 1 10 by the persons operating the engine 102. As an example, an engine that is small in size may require only single HMI unit 1 10, whereas an engine that is large in size likely benefits from a plurality of HMI units 1 10 to enable timely and convenient access to the control functions enabled by the HMI units 1 10 at multiple locations.

The engine control system 100 further comprises a safety control database (SCDB) 120, which may be provided in a data storage means that is communi- catively coupled to the HMI units 1 10. The data storage means applied for storing the SCDB 120, in turn, may be provided e.g. as a dedicated data storage entity (as depicted in the example of Figure 1 ), as part of the ECl 101 or as part of one of the HMI units. Due to the communicative coupling, each of the HMI units 1 10-k is able to read data from the SCDB 120 and write data to the SCDB 120. The information content and purpose of the SCDB 120 is described later in this text.

In the example of Figure 1 the communicative coupling between components of the engine control system 100 is provided by a bus 105, which may comprise e.g. a controller area network (CAN) bus or another suitable bus known in the art. Although depicted as a single bus entity that serves as means for connecting the HMI units 1 10, the ECI 101 and to the SCDB 120 to each other, the bus 105 may be provided as one or more separate buses.

A HMI unit 1 10-k may be integrated to a component or part of the engine 102, e.g. by arranging the HMI unit 1 10-k in a housing of the engine 102. As anoth- er example, the HMI unit 1 10-k may be arranged in close proximity to the engine 102, e.g. in a respective 'control desk' arranged in immediate proximity to the engine 102, in an engine room or in an engine control room.

As described in the foregoing, the HMI unit 1 10 comprises a Ul that provides access to one or more user functions that enable a user to control a respective aspect of the engine operation. In this regard, Figure 2 schematically illustrates the Ul aspect of the HMI unit 1 10 according to an example. Herein, the HMI unit 1 10 comprises display means 1 12 for displaying visual information to a user. The display means may be provided as an electronic display, such as a light-emitting diode (LED) display, an organic light-emitting diode (OLED) dis- play, an electroluminescent display (ELD), a liquid crystal display (LCD), etc. The HMI unit 1 10 further comprises a user input means 1 14 for receiving input from the user. In the example of Figure 2, the user input means 1 14 includes an arrangement of programmable push-buttons, which may referred to as soft- keys. The function invoked by operating a given softkey may be described by a text or by a visual identifier in a portion of the display means 1 12 adjacent to the given softkey, whereas the remaining part of the display 1 12 may be employed e.g. for displaying information that is indicative of the current status one or more aspects of the engine operation.

Instead of or in addition to the softkeys shown in the example of Figure 2, the user input means may comprise elements or components of other type, e.g. one or more of the following: one or more further arrangements of keys or buttons (in another location(s)) of the Ul, a keyboard, a mouse or a pointing device of other type, a touchpad, etc. In a further example, the display means 1 12 is provided as a touchscreen, thereby providing at least part of the user input means 1 14 as a component integrated to the display means 1 12. In the example of Figure 2 the engine control functions accessible by the user via the softkeys of the user input means 1 14 are described in a generic manner as Tunc 1 ", Tunc 2" and Tunc 3" and they serve to represent any suitable respective engine control functions. As examples in this regard, the engine functions that are controllable via the Ul provided in the HMI unit 1 10-k typically include at least an engine control function for starting the engine 102 and an engine control function for stopping the engine 102. The Ul, however, may provide a number of additional control functions for adjusting a certain operating characteristic of the engine 102 and/or for selecting information indicative of a certain operating characteristic of the engine 102 to be displayed via the display means 1 12. As a few examples in this regard, control functions for adjusting an operating characteristic of the engine 102 or for selecting information indicative of a certain operating characteristic of the engine 102 to be displayed may comprise one or more of the following: - adjusting the speed of the engine 102;

- switching a function of the engine 102 on or off;

- selecting a predefined operating characteristic of the engine to be displayed via the display means 1 12;

- resetting any user-controllable functions of the engine 102 to their re- spective predefined default statuses (e.g. on or off);

- resetting any user-adjustable control parameters of the engine 102 to their respective predefined default values.

In case the engine control system 100 comprises a plurality of HMI units 1 10, the engine control functions available via user functions provided in the re- spective Uls of the HMI units 1 10 may vary from one HMI unit 1 10 to another. In other words, a first set of engine control functions that are accessible via the Ul in a first HMI unit 1 10-k need not be the same as a second set of engine control functions that are accessible via a second HMI unit 1 10-j (where k≠ j). Typically, though, the engine control functions available in different HMI units 1 10, e.g. the first and second sets of engine control functions, share one or more engine control functions, e.g. the engine control function for starting the engine 102 and/or the engine control function for stopping the engine 102.

At least one of the HMI units of the engine control system 100, referred to herein as the HMI unit 1 10-k, further comprises a lock means 1 16 for receiving a safety key. The HMI unit 1 10-k is configured to selectively provide via its Ul a locking function or unlocking function for controlling availability of one or more engine control functions (otherwise) provided via respective Uls of one or more HMI units 1 10 of the engine control system 100 when the lock means 1 16 is in receipt of the safety key. A safety key represents a predefined key identifier (ID) assigned therefor, which key ID serves as a unique identification of the particular safety key. Each key ID, and hence each safety key, is associated with one or more engine control functions that are (normally) available via respective Ul of at least one HMI unit 1 10 of the engine control system 100.

The information that defines the mapping between a key ID and the associated engine control function may be stored in the SCDB 120. As a non-limiting example in this regard, in order to provide the mapping between a key ID and the associated engine control functions whose availability the key ID serves to control, the SCDB 120 may include a key information table that comprises a respective table entry for each key ID configured for use in the engine control system 100. Therein, each table entry includes the respective key ID, identifications of one or more associated engine control functions associated with the key ID (i.e. one or more engine control functions whose availability via the HMI units 1 10 is controllable by the key ID) of the same table entry, and an indication whether the respective key ID is currently applied to lock the associated engine control function(s).

Table 1 in the following provides an illustrative example of a content of a key information table. Therein, three key IDs (#1 , #2 and #3) are considered, where the key IDs #1 and #2 are associated with the engine control functions Tunc 1 " and Tunc 2", whereas the key ID #3 is associated with the engine control functions Tunc 1 ", Tunc 2" and Tunc 3". Moreover, the example of Table 1 further indicates the key ID #2 is currently being applied to lock the engine control functions associated therewith (i.e. the engine control function Tunc 1 "), whereas there is no indication of other key IDs being currently applied to lock the respective associated engine control functions.

Table 1

While the mapping between the available key IDs and the respective associated engine control functions complemented with information that indicates whether the key ID is currently being applied to lock the associated engine control functions would be sufficient for the HMI units 1 10 of the engine control system 100 to acquire information regarding the engine control functions they are currently allowed to make accessible for a user via the respective Uls, the SCDB 120 may additionally include information that defines for each engine control function that is accessible via at least one of the HMI units 1 10 of the engine control system 100 and whose availability is controllable through at least one key ID whether it is currently available (and/or currently non- available).

As an example in this regard, the SCDB 120 may additionally include a control function status table that comprises a respective table entry for each engine control function whose availability is controllable though at least one key ID configured for use in the engine control system 100. Therein, each table entry includes an identification of the respective engine control function and an indication whether any key IDs are currently applied to lock this engine control function. As non-limiting examples, the latter piece of information may be provided as a list of zero or more key IDs that identify those safety keys that are currently applied to lock this engine control function or as an indication of the number of key IDs that are currently applied to lock this engine control function.

Table 2 in the following provides an illustrative example of a content of a control function status table. Therein, three engine control functions (Tunc 1 ", Tunc 2" and Tunc 3") are considered. According to the example provided by Table 2, the control function Tunc 1 " is indicated as currently locked via usage of the key ID #1 and the control function Tunc 2" is indicated currently locked via usage of the key IDs #1 and #3 (the Table 2 hence exemplifying the approach where the indication whether any key IDs are currently applied to lock this engine control function is provided by listing the associated key IDs), while no key IDs are currently applied to lock the engine control function Tunc 3".

Table 2

In the following, we refer to a key ID read from a safety key received by the lock means 1 16 in a HMI unit 1 10-k as the key ID(k). In response to the lock means 1 16 in a HMI unit 1 10-k receiving a safety key, the key ID(k) is obtained (e.g. read) from the safety key and the SCDB 120 is accessed to determine whether the key ID(k) is currently being applied to lock the one or more engine control functions associated therewith. This determination may be carried out e.g. by identifying the table entry of the key information table in the SCDB 120 that corresponds to the key ID(k) and determining whether the identified table entry indicates locking of the associated control function(s).

In case the determination is non-affirmative (i.e. no current locking of the associated engine control functions by using the key ID(k)), the Ul of the HMI unit 1 10-k is updated to enable the locking function that serves to disable the en- gine control functions associated with the key ID(k). An illustrative example in this regard is provided in Figure 3A, where the lowermost softkey of the user input means 1 14 (identified by the text "LOCK" in a portion of the display means 1 12 adjacent thereto) enables locking of the associated engine control functions by using the key ID(k).

In case the determination is affirmative (i.e. the associated engine control functions are currently locked by using the key I D(k)), the Ul of the HMI unit 1 10-k is updated to enable the unlocking function that serves to release (unlock) the engine control functions associated with the key ID(k) from being locked by us- ing the key ID(k). An illustrative example in this regard is provided in Figure 3B, where the lowermost softkey of the user input means 1 14 (identified by the text "UNLOCK" in a portion of the display means 1 12 adjacent thereto) enables unlocking of the associated engine control functions. The illustrative example of Figure 3B further shows the engine control function Tunc 1 " associated with the key ID(k) being disabled (indicated by the de-emphasized associated text Tunc 1 " in a portion of the display means 1 12 adjacent to the uppermost soft- key of the user input means 1 14) due to locking (at least) by the key ID(k).

Referring back to the scenario exemplified by Figure 3A (where there is no current locking of the associated engine control functions by using the key ID(k)), if the user engages the locking function via the Ul of the HMI unit 1 10-k (e.g. operates the softkey identified with the text "LOCK" in Figure 3A), these control functions become (temporarily) locked by the key I D(k), which may result in at least the following operations to be carried out by components of the engine control system 100: - The SCDB 120 is updated to indicate the locking of the engine control functions associated with the key ID(k) by the key ID(k). In an example, this results in the HMI unit 1 10-k updating the respective table entry of the key information table in the SCDB 120 to indicate disablement of the associated engine control functions and possibly also updating the con- trol function status table in the SCDB 120 to indicate that the engine control functions associated with the key ID(k) are disabled at least due to engagement of the locking function using the key ID(k).

- The Ul of the HMI unit 1 10-k is updated to disable the associated engine control functions and Ul of the HMI unit 100-k is further updated to enable, instead of the respective locking function, the unlocking function that allows the user to release (unlock) the associated engine control functions from being locked by the key ID(k). An illustrative example in this regard is provided in Figure 3B, where the lowermost softkey of the user input means 1 14 enables unlocking of the associated engine con- trol functions and where the engine control function Tunc 1 " associated with the key ID(k) is disabled (as described above).

- The respective Uls of the other HMI units 1 10 are updated to disable the engine control functions associated with the key ID(k) where necessary, i.e. in the respective Uls of those HMI units 1 10 that otherwise en- able one or more of the engine control functions associated with the key

ID(k). The other HMI units 1 10 may obtain an indication of the engine control functions to be disabled in their respective Uls by accessing the key information table and/or the control function status table in the SCDB 120. The other HMI units 1 10 may receive such indication, for example, by periodically (e.g. at predefined time intervals) accessing the respective table(s) of the SCDB 120 or via the HMI unit 1 10-k sending, to the other HMI units 1 10, an indication regarding the locking function for locking the engine control functions associated with the key ID(k) having been engaged. Referring back to the scenario exemplified by Figure 3B (where the associated engine control functions are currently locked by using the key ID(k), if the user engages the unlocking function via the Ul of the HMI unit 1 10-k (e.g. operates the softkey identified with the text "UNLOCK" in Figure 3B), these control functions are released from locking by the key ID(k), which may result in at least the following operations to be carried out by components of the engine control system 100: The SCDB 120 is updated to indicate the release (unlocking) of the engine control functions associated with the key ID(k) from locking by the key ID(k). In an example, this results in the HMI unit 1 10-k updating the respective table entry of the key information table in the SCDB 120 to indicate release of the associated engine control functions from locking by the key ID(k) and possibly also updating the control function status table in the SCDB 120 to indicate that the engine control functions associated with the key ID(k) are not any more locked due to engagement of the locking function with the key ID(k).

The Ul of the HMI unit 1 10-k is updated to re-enable the associated engine control functions in case there are no other key IDs that are currently being applied to lock one or more of these engine control functions. Moreover, the Ul of the HMI unit 100-k is updated to enable, instead of the respective unlocking function, the locking function that allows the user to lock the associated engine control functions. As an example, these operations may return the Ul in the HMI unit 1 10-k back into the state exemplified in Figure 3A.

The respective Uls of the other HMI units 1 10 are updated to re-enable the engine control functions associated with the key ID(k) where necessary, provided that there are no other key IDs that are currently being applied to lock the one or more of these engine control functions. The other HMI units 1 10 may obtain an indication of the engine control functions to be re-enabled in their respective Uls by accessing the key information table and/or the control function status table in the SCDB 120. The other HMI units 1 10 may receive such indication, for example, by periodically (e.g. at predefined time intervals) accessing the respective table(s) of the SCDB 120 or via the HMI unit 1 10-k sending, to the other HMI units 1 10, an indication regarding the unlocking function for releasing (unlocking) the engine control functions associated with the key ID(k) having been engaged.

As described in the foregoing, the locking function or the unlocking function for controlling availability of one or more engine control functions associated with the key ID(k) is available only when the lock means 1 16 in the HMI unit 1 10-k is in receipt of the safety key that represents the key ID(k). Thus, when the safety key is disconnected from the lock means 1 16 of the HMI unit 1 10-k, the Ul of the HMI unit 1 10-k is updated such that the locking function or the un- locking function is no longer available via the Ul. However, in case a safety key representing the key ID(k) was applied to lock the engine control functions associated therewith, these engine functions remain locked by the key ID(k) and thereby disabled through the respective Uls of the HMI units 1 10 of the engine control system 100 until released (unlocked) using the same safety key. As becomes apparent from the example provided in the foregoing, the locking function or the unlocking function for controlling availability of one or more engine control functions associated with the key I D(k) is available only via the Ul of the HMI unit 1 10-k in which the lock means 1 16 is in receipt of the safety key representing the key ID(k). This ensures that only the person accessing the engine control functions via the Ul in the HMI unit 1 10-k has the control for locking or unlocking the associated engine control functions, thereby facilitating prevention of unauthorized persons from disabling or re-enabling the associated engine control functions.

In an example, the user may use his/her safety key to (first) enable and en- gage the locking function to lock the engine control functions associated with the key ID represented by his/her safety key via the Ul of the HMI unit 1 10-k, carry out desired maintenance operations on the engine 102, and (subsequently) enable and engage the unlocking function to release the respective associated engine control functions via the Ul of the same HMI unit 1 10-k. In another example, the user uses his/her safety key to (first) enable and engage the locking function to lock the associated engine control functions via the Ul of the HMI unit 1 10-k, carry out desired maintenance operations on the engine 102, and (subsequently) enable and engage the unlocking function to release the respective associated engine control functions via the Ul of another HMI unit 1 10-j (where j≠ k). In an example, locking of the associated engine control functions may further require, in addition to the user engaging the locking function via the Ul of the HMI-unit 1 10-k, receiving a valid personal identification code via the Ul of the HMI-unit 1 10-k. Along similar lines, additionally or alternatively, releasing (un- locking) of the associated engine control functions may further require, in addition to the user engaging the unlocking function via the Ul of the HMI-unit 1 10- k, receiving the valid personal identification code via the Ul of the HMI-unit 1 10-k.

As an example in this regard, the user engaging the locking or unlocking func- tion (e.g. via operating the respective softkey of the user input means 1 14) may be followed by the HMI unit 1 10-k requesting, via the Ul, the user to enter the personal identification code, such as a password or a PIN code, assigned to the key ID(k) before the HMI unit 1 10-k proceeds with implementing the locking or release of the associated engine control functions. The user may apply e.g. a keyboard provided in the HMI unit 1 10-k or a touchscreen of the HMI unit 1 10-k to enter the personal identification code. The code entered by the user is compared to the personal identification code assigned to the key ID(k) and the HMI unit 1 10-k may proceed with implementing the locking or release of the associated engine control functions in response to the user- entered code matching the personal identification code assigned to the key ID(k). Usage of the personal identification code serves as an additional safety measure that facilitates prevention of unauthorized persons from locking or releasing the associated engine control functions.

In an example, the lock means 1 16 and the safety key(s) are provided using universal serial bus (USB) technology known in the art. As an example in this regard, the lock means 1 16 may be provided as an USB port and one or more safety keys may be provided as respective USB devices, e.g. as respective US memory sticks, each arranged to store information that serves as an indication of the respective key ID assigned thereto in a predefined format. In this exam- pie, the lock means 1 16 is in receipt of a safety key when the USB device is connected to the USB port such that HMI unit 1 10-k is able to read the key ID therefrom.

In another example, the lock means 1 16 and the safety key(s) are provided by employing a radio frequency identification (RFID) technique known in the art. As an example in this regard, the lock means 1 16 may be provided as an RFID reader and one or more safety keys may be provided as respective RFID tags, each arranged to store information that serves an indication of the respective key ID assigned thereto. In this example, the lock means 1 16 is in receipt of a safety key when the RFID reader is able to read the key ID from the ID tag.

In a further example, the lock means 1 16 and the safety key(s) are provided by employing a near field communication (NFC) technique known in the art. As an example in this regard, the lock means 1 16 may be provided as a first NFC device and one or more safety keys may be provided as respective second NFC devices, each arranged to store information that serves an indication of the respective key ID assigned thereto. In this example, the lock means 1 16 is in receipt of a safety key when the first NFC device is able to read the key ID from the second NFC device.

In a further example, the lock means 1 16 and the safety key(s) are provided by employing a fingerprint recognition technique known in the art. As an example in this regard, the lock means 1 16 may be comprise a fingerprint sensor and a safety key for a certain user comprises a finger of the certain user. In such an approach, the lock means 1 16 may store one or more predefined fingerprint templates, each fingerprint template associated with a respective key ID. The lock means 1 16 further compares a fingerprint obtained via the fingerprint sensor to the stored one or more predefined fingerprint templates and obtains the key ID as the key ID associated with the predefined fingerprint template recognized to match (e.g. to be similar or substantially similar to) the fingerprint obtained via the fingerprint sensor.

In a further example, the lock means 1 16 and the safety key(s) are provided by employing a facial recognition system or technique known in the art. As an ex- ample in this regard, the lock means 1 16 may comprise imaging means (such as a digital camera) and a safety key for a certain user comprises the face of the certain user (or part thereof). In such an approach, the lock means 1 16 may store one or more sets of predefined facial features, each set associated with a respective key I D. The lock means 1 16 further compares facial features extracted from an image of a face obtained from the imaging means to the stored one or more sets of predefined facial features and obtains the key ID as the key ID associated with the set of predefined facial features found to match (e.g. to be similar or substantially similar to) the facial features extracted from the image of a face obtained from the imaging means.

In a further example, the lock means 1 16 and the safety key(s) are provided by employing an iris recognition system or technique known in the art. As an example in this regard, the lock means 1 16 may comprise imaging means (such as a digital camera) and a safety key for a certain user comprises an iris of the certain user (or part thereof). In such an approach, the lock means 1 16 may store one or more predefined iris templates, each associated with a respective key ID. The lock means 1 16 further compares an image of an iris obtained from the imaging means to the stored one or more iris templates and obtains the key ID as the key ID associated with the predefined iris template found to match (e.g. to be similar or substantially similar to) the image of an iris obtained from the imaging means.

Figure 4 illustrates a block diagram of some components of an engine control system 200 according to an example, which is a variation of the engine control system 100, operation of which is described in the foregoing by a number of examples. In addition to the one or more HMI units 1 10 and the SCDB 120, the engine control system 200 further comprises a local central control unit (LCCU) 130 that is communicatively coupled to the SCDB 120 and to the ECI 101 , and possibly also to the HMI units 1 10.

Like the HMI units 1 10, the LCCU 130 comprises a Ul that provides one or more engine control functions for controlling operation of an engine 102. Typically, although not necessarily, the Ul of the LCCU 130 provides an enlarged selection of engine control functions in comparison to the respective Uls of the HMI units 1 10. As an example in this regard, the Ul of the LCCU 130 may provide all those engine control functions that are available via the respective Uls of any of the HMI units 1 10 of the engine control system 200 and it may pro- vide one or more further engine control functions that are not available via the respective Uls of any of the HMI units 1 10 of the engine control system 200.

The LCCU 130 is, typically, provided in a control center or in a control room that is located in the site of the engine 102, e.g. in or close to an engine room of a marine vessel (at least in part) powered by the engine 102 or in or close to engines of an engine-powered power plant that is (at least in part) powered by the engine 102. The control center/room that hosts the LCCU 130 is typically provided somewhat further away from the engine 102 (and possible other engines of the site) than any of the HMI units 1 10 of the engine control system 200.

Due to the communicative coupling, the LCCU 130 is able to read data from the SCDB 120 and write data to the SCDB 120. Therefore, in case the any of the HMI units 1 10 have been applied to engage the locking function to lock some of the engine control functions available in the engine control system 200, the LCCU 130 may access the SCDB 120 (e.g. the key information table and/or the control function status table therein) to obtain an indication in this regard and disable access to the associated engine control functions via the Ul of the LCCU 130 accordingly. Along similar lines, if any of the HMI units 1 10 have been applied to engage the unlocking function after a time period of some of the engine control functions (otherwise) available via the Ul of the LCCU 130 having been disabled due to engagement of the respective locking function, the LCCU 130 may access the SCDB 120 (e.g. the key information table and/or the control function status table therein) to obtain an indication in this regard and re-enable access to the associated engine control functions via the Ul of the LCCU 130 accordingly. Like the HMI units 1 10, also the LCCU 130 may comprise a lock means 136 for receiving the safety key. The operation of the LCCU 130 when in receipt of the safety key is similar to that described in the foregoing in context of the HMI unit 1 10-k, mutatis mutandis. In particular, a safety key may be applied in the LCCU 130 to enable, via the Ul of the LCCU 130, locking or releasing (unlocking) the associated engine control functions in the HMI units 1 10 (as well as via the Ul of the LCCU 130) of the engine control system 200.

Figure 5 illustrates a block diagram of some components of an engine control arrangement that comprises the engine control system 100 and the LCCU 130. Although not shown in the illustration Figure 5, the LCCU 130 connects to the engine control system 100 via the bus 105. Moreover, in the example of Figure 5 the LCCU 130 is provided outside the engine control system 100 and it is connected to one or more further engine control systems 100' (represented in the Figure 5 by two instances denoted by the reference designator 100'). Each of the engine control systems 100' is arranged to control operation of the respective engine via a respective ECI (e.g. along the lines described in the foregoing for the engine control system 100). Hence, in this engine control arrangement the LCCU 130 serves to provide control over a plurality of (e.g. two or more) engines via the respective engine control systems 100, 100'.

In an example in this regard, the LCCU 130 is provided with a single lock means via which control over availability of the engine control functions in each of the engine control systems 100, 100' coupled thereto may be provided by using a single safety key (e.g. by reading/writing the respective SCDBs 120 of the engine control systems 100, 100' and controlling availability of the engine control functions via respective Uls of the HMI units 1 10 in the engine control systems 100, 100' (and via the Ul of the LCCU 130) accordingly, e.g. as described in the foregoing in context of the HMI units 1 10 of the engine control system 100). Alternatively, in this scenario the Ul of the LCCU 130 may enable the user selecting the engine control systems 100, 100' to be affected in response to receiving the safety key in the lock means.

In another example, the LCCU 130 (in the engine control arrangement of Fig- ure 5) may be provided with a dedicated lock means for each of the engine control systems 100, 100' coupled to the LCCU 130. In this scenario, a single safety key is useable to control availability of the engine control functions in single one of the engine control systems 100, 100' coupled to the LCCU 130 at a time, in the engine control system 100, 100' that is associated with the lock means that is currently in receipt of the safety key. Figure 6 depicts a flowchart that outlines a method 300 according to an example embodiment. The method 300 may implement some aspects of the engine control system 100 described in the foregoing by a number of examples. The method 300 may be carried out by one or more computing devices that are arranged to implement at least the one or more HMI units 1 10 and the SCDB 120. The method 300 serves to control user access to one or more engine control functions in the engine control system 100 that is communicatively coupled to the engine 102 via the ECI 101 . The method 300 comprises operating the one or more HMI units 1 10, each HMI unit 1 10 comprising a respective Ul for providing user access to respective one or more engine control functions, wherein at least one HMI unit 1 10 comprises the respective lock means 1 16 for receiving a safety key storing a key ID, which key ID has at least one engine control function associated therewith, as indicated in block 310. The method further comprises selectively providing, via the Ul of a first HMI unit, when the lock means 1 16 in the first HMI unit is in receipt of the safe- ty key storing a first key ID one of the following: a locking function for locking said at least one engine control function by the first key ID and an unlocking function for releasing said at least one engine control function from locking by the first key ID, as indicated in block 320.

The method 300 may further comprise one or more of operations described in blocks 330A and 330B: disable, via the respective Ul of each of the HMI units 100, in response to a user engaging the locking function via the Ul of the first HMI unit, user access to said at least one engine control function associated with the first key ID (block 330A) and/or re-enable, via the respective Ul of each of the HMI units 100, in response to a user engaging the unlocking func- tion via the Ul of the first HMI unit, user access to those ones of said at least one engine control function associated with the first key ID that are not locked by one or more other key IDs (block 330B).

The method 300 outlined herein may be varied in a number of ways, e.g. as described in context of the engine control system 1 00, 100' or the engine con- trol arrangement described with references to Figure 5.

Components of the engine control system 100, 100' may be provided by using respective hardware means, respective software means, or respective combination of hardware means and software means. In particular, each of the HMI units 1 10, the SCDB 120 and the LCCU 130 may be provided respective hardware means, respective software means, or respective combination of hardware means and software means.

As an example of providing a component of the engine control system 100, 100' using a combination of hardware means and software means, Figure 7 schematically illustrates some components of an exemplifying apparatus 400 suited for this purpose. The apparatus 400 comprises a processor 402 and a memory 404 for storing data and computer program code 406. In case of the SCDB 120 the memory 404 may store information that constitutes the SCDB 120. The processor 402 is configured to read from and write to the memory 404. The apparatus 400 further comprises a communication means 408 for communicating with another apparatuses or devices, e.g. with other components of the engine control system 100, 100'. The apparatus 400 further comprise user I/O (input/output) components 410 that may be arranged, together with the processor 402 and a portion of the computer program code 406, to provide a user interface for receiving input from a user and/or providing output to the user. The user I/O components 410 may comprise hardware components such as a display, a touchscreen, a touchpad, a mouse, a keyboard and/or an arrangement of one or more keys or buttons, etc. In particular, at least some of the user I/O components 410 may serve to provide the display means 1 12 and the user input means 1 14 of a HMI unit 1 10 described in the foregoing. The processor 402 may be arranged to control operation of the apparatus 400 in accordance with a portion of the computer program code 406 stored in the memory 404 and possibly further in accordance with the user input received via the user I/O components 410 and/or in accordance with information re- ceived via the communication means 408. The memory 404 and a portion of the computer program code 406 stored therein may be further arranged, with the processor 402, to provide a control function or control means for controlling operation of the apparatus 400. The processor 402, the memory 404, the communication means 408 and the user I/O components 410 may be inter- connected by a bus 412 that enables transfer of data and control information. The apparatus 400 may comprise further components in addition to those shown in the illustration of Figure 7.

Although the processor 402 is depicted as a single component, the processor 402 may be implemented as one or more separate processing components. Similarly, although the memory 402 is depicted as a single component, the memory 404may be implemented as one or more separate components, some or all of which may be integrated/removable and/or may provide permanent / semi-permanent/ dynamic/cached storage.

The computer program code 406 stored in the memory 404 may comprise computer-executable instructions that control the operation of the apparatus 400 when loaded into the processor 402. The computer program code 406 may include one or more sequences of one or more instructions. The processor 402 is able to load and execute the computer program code 406 by reading the one or more sequences of one or more instructions included therein from the memory 404. The one or more sequences of one or more instructions may be configured to, when executed by the processor 402, cause the apparatus 400 to carry out operations, procedures and/or functions described in the foregoing in context of the respective component of the engine control system 100, 100', e.g. those described for the HMI unit 1 10, the SCDB 120 or the LCCU 130. The computer program code 406 may be provided e.g. as a computer program product comprising at least one computer-readable non-transitory medium having program code stored thereon, the computer program code 406, when executed by the apparatus 400, arranged to cause the apparatus 400 to carry out operations, procedures and/or functions described in the foregoing in context of the respective component of the engine control system 100, 100', e.g. those described for the HMI unit 1 10, the SCDB 120 or the LCCU 130. The computer-readable non-transitory medium may comprise a memory device or a record medium such as a CD-ROM, a DVD, a Blu-ray disc or another article of manufacture that tangibly embodies the computer program. As another example, the computer program may be provided as a signal configured to reliably transfer the computer program.

Reference(s) to a processor should not be understood to encompass only programmable processors, but also dedicated circuits such as field-programmable gate arrays (FPGA), application specific circuits (ASIC), signal processors, etc. Features described in the preceding description may be used in combinations other than the combinations explicitly described.

Features described in the preceding description may be used in combinations other than the combinations explicitly described. Although functions have been described with reference to certain features, those functions may be performa- ble by other features whether described or not. Although features have been described with reference to certain embodiments, those features may also be present in other embodiments whether described or not.