AUDIO

FIELD OF THE INVENTION

The present invention generally relates to process control systems. More particularly the present

invention relates to a method, sound processing

arrangement and a computer program product for enabling a user of a process control system to determine the health of a process control object.

BACKGROUND A process control system normally comprises a number of process control objects involved in the control of the process .

In process control systems there are furthermore maintenance engineers that are most of the time working on the process floor close to these process control objects, which is typically far away from control rooms with work stations and other computers from which the system is monitored. The maintenance engineers make sure the process runs as smooth as possible by both preventive and direct maintenance.

Plant maintenance engineers thus work to ensure that the process is running as uninterrupted and smooth as possible. It is of highest importance for them to be able to predict and detect any malfunctions in the plant. Issues may need to be corrected as soon as possible to minimize disturbance to the process. When the plant maintenance engineer detects and identifies a problem it is equally important to be able to correctly diagnose the problem and do the necessary repairs. It has been confirmed in user studies that plant maintenance engineers use the generated sound from the process control objects to detect abnormalities as some of these objects sound different when there is need for maintenance. For that reason audio is a powerful tool that may be used for recognizing upcoming problems.

This however requires the plant maintenance engineer to be experienced in order to be able to detect the sounds that can indicate an upcoming malfunction. Some techniques have been developed that use audio for detecting malfunctions of equipment in various areas of technology .

US 7490011 does for instance disclose the use of sound profiles for diagnosing energy conversion appliances.

The document more particularly describes that sound can be used for recognizing correct operation or failure and also in which part of the operation there is a failure .

DE 10253564 discusses recording of sound from a

machine. The sound may be recorded as a reference with which later recorded sound may be compared and

deviations detected. The document also discusses comparing the later recorded sound with sound that was recorded earlier. Despite the teachings of these documents, there is still a need for improvement within the field.

The present invention addresses one or more of the above-mentioned issues.

SUMMARY OF THE INVENTION

The present invention addresses the problem of

simplifying the diagnostics of process control objects in a process control system using sounds.

This object is according to a first aspect of the invention achieved through a method of enabling a user of a process control system to determine the health of a process control object, the method being performed by a sound processing arrangement, the sound processing arrangement comprising a wireless terminal and the method comprising:

detecting that the wireless terminal is in the

proximity of a process control object,

recording, based on the detection, sounds of the process control object, and

providing the recorded sounds to a sound analysing unit in order to have the health of the process control object determined.

This object is according to a second aspect of the invention achieved through a sound processing

arrangement for enabling a user of a process control system to determine the health of a process control object, the sound processing arrangement comprising: a wireless terminal with a sound recording unit, and a detecting unit configured to detect that the wireless terminal is in the proximity of a process control obj ect ,

wherein the sound recording unit is configured to

record, based on the detection, sounds (RS) of the process control object, and

provide the recorded sounds to a sound analysing unit in order to have the health of the process control object determined.

This object is according to a third aspect of the invention solved through a computer program product for enabling a user of a process control system to

determine the health of a process control object, the computer program product being provided on a data carrier comprising computer program code configured to cause a sound processing arrangement comprising a wireless terminal to, when the computer program code is loaded into at least one device providing the sound processing arrangement,

detect that the wireless terminal is in the proximity of a process control object,

record, based on the detection, sounds of the process control object, and

provide the recorded sounds to a sound analyzing unit in order to have the health of the process control object determined.

The present invention has a number of advantages. Sound of process control objects are automatically recorded as a user moves in the proximity of them. This enables automatic diagnosis of the process control objects using sound. The users may be more effective as they do not have to concern themselves with the activity of recording of sound. The tasks of the user can thereby be finished faster than otherwise. The user does also not have to be experienced. The invention is

furthermore easily implemented in a process control system using the existing functionality of wireless terminals .

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will in the following be

described with reference being made to the accompanying drawings, where Fig. 1 schematically shows an industrial plant with a process control system operating an industrial process together with a wireless terminal associated with a maintenance engineer,

Fig. 2 schematically shows a front view of a wireless terminal,

Fig. 3 schematically shows a block schematic of the wireless terminal,

Fig. 4 shows premises of the industrial plant with a number of rooms, where the wireless terminal is in a first of the rooms comprising two process control obj ects ,

Fig. 5 schematically shows the user in the first room in the proximity of a first of the two process control obj ects ,

Fig. 6 schematically shows a view shown on the display of the wireless terminal, Fig. 7 shows a flow chart of a number of method steps being performed in a method of enabling a user of the process control system to determine the health of a process control object, and

Fig. 8 schematically shows a data carrier with computer program code, in the form of a CD-ROM disc, for

performing the steps of the method.

DETAILED DESCRIPTION OF THE INVENTION

In the following, a detailed description of preferred embodiments of a method, sound processing arrangement and a computer program product for enabling a user of a process control system to determine the health of a process control object will be given.

Fig. 1 schematically shows an industrial plant where a process control system 10 is provided. The process control system 10 is a computerized process control system for controlling an industrial process. The process can be any type of industrial process, such as electrical power generation, transmission and

distribution processes as well as water purification and distribution processes, oil and gas production and distribution processes, petrochemical, chemical, pharmaceutical and food processes, and pulp and paper production processes. These are just some examples of processes where the system can be applied. There exist countless other industrial processes. The processes may also be other types of industrial processes such as the manufacturing of goods. A process may be monitored through one or more process monitoring computers, which communicate with a server handling monitoring and control of the process.

In fig. 1 the process control system 10 therefore includes a number of process monitoring computers 12 and 14. These computers may here also be considered to form operator terminals and are connected to a first data bus Bl . There is also a gateway 16 connected to this first data bus Bl, which gateway 16 is connected to at least one wireless network WN. To the wireless network WN there is connected a wireless terminal 32. It should be realized that it is possible with more wireless terminals in the wireless network WN. However, only one is shown for simplifying the understanding of the present invention. The wireless network WN may be a local network, such as a wireless local area network (WLAN) . It may also be a Bluetooth network, i.e. a network with a number of interconnected Bluetooth nodes .

There is furthermore a second data bus B2 and between the first and second data busses Bl and B2 there are connected a server 18 providing control and protection of the process and a database 20 where data relating to control and protection of the process is stored. Such data relating to control and protection may here comprise process data such as measurements and control commands, while data relating to protection may

comprise alarm and event data as well as data on which alarms and events can be generated, such as

measurements made in the process. There is furthermore a sound handling server 23 connected between the two buses Bl and B2. The sound handling server 23 comprises a positioning block 21 and a sound handling block 22.

To the second data bus B2 there is furthermore

connected a number of further devices 24, 26, 28 and 30. These further devices 24, 26, 28 and 30 are field devices, which are devices that are interfaces to the process being controlled. A field device is typically an interface via which measurements of the process are being made and to which control commands are given. Because of this the field devices are furthermore process control objects. In one variation of the invention a first field device is a first process control object 24, as an example a motor, and the second field device is a second process control object 26, as an example a centrifuge.

Fig. 2 schematically shows a front view of the wireless terminal 32. It simply comprises a display 34 and a microphone 35. The display 34 is in some variations of the invention a touch screen via which data can be presented for the user of the wireless terminal 32 as well as via which data can be entered by the user, such as selections of various features in applications. It should be realized that in other variations of the invention the display may only be a display and the inputs provided through a keypad or a keyboard, a trackball, a joystick or some other buttons. Fig. 3 shows a block schematic of the wireless terminal 32. The wireless terminal 32 comprises a bus 33 and to this bus there is connected the display 34, a recording controller 36, a program memory 39, a processor 40, as well as a radio communication circuit 42. The radio communication circuit 42 is furthermore connected to an antenna 44, where the radio communication unit 42 and first antenna 44 are provided for communication with the wireless network WN. The recording controller 36 is in turn connected to the microphone 35.

In the program memory 39 there is provided optional software code or computer program instructions which when being run by the processor forms a positioning element 37 and a sound handling element 38.

Fig. 4 schematically shows a facility 45 of the

industrial plant. The facility 45 is here in the form of a building with a number of rooms. There is here a first room. In this first room the first and second process control objects 24 and 26 are located. In the first room there is a first wireless access point 46 of the wireless network. In this figure also the first wireless terminal 32 is located in the first room, which indicates that also the corresponding user is in this first room. Next to the first room there is a second room with a second wireless access point 48. The second room in turn leads to a third larger room with a third wireless access point 50. In the third room there is a door leading out of the premises 49 and outside of the premises there is a fourth wireless access point 52. The access points 46, 48 50 and 52 are here

furthermore located close to doors leading to or from the rooms. The first wireless access point 46 is therefore provided close to a door interconnecting the first and the second rooms, the second wireless access point 48 is located close to a door interconnecting the second and the third rooms, the third wireless access point 50 is provided close to the door leading out of the building 45 and the fourth wireless access point 52 is provided close to the same door at the exterior of the building 45. The above described access point positions close to doors are only exemplary. The invention is thus in no way limited to these positions. Others may be used. The first room is here also shown as providing an area A, that surrounds the first process control object 24. The area A is here exemplified by a circular area, which thereby has a radius r. Furthermore the positions of the wireless access points 46, 48 and 50 and 52 are typically known and because of this also the positions of the wireless terminals and consequently the users may be known. A first embodiment of the invention will now be

described with reference also being made to fig. 5 - 7, where fig. 5 schematically shows the user 54 of the wireless terminal WT 32 in the first room in proximity of the first process control objects M 24, fig. 6 schematically shows a view shown on the display 34 of the wireless terminal 32 and fig. 7 shows a flow chart of a number of method steps being performed in a method of enabling a user of the process control system to determine the health of a process control object.

The wireless terminals available today are equipped with a lot of different sensors, such as Global

Positioning System (GPS) , Bluetooth, and Near Field Communication (NFC) . Using these sensors as well as other communication systems it is possible to detect the position of the wireless terminal in a number of ways. If the process control system 10 is also aware of the physical position of process control objects then it is possible to determine when a wireless terminal is moving close to a certain process control object.

Furthermore, wireless terminals are also often equipped with high quality microphones with noise reduction capabilities. These may be used in order to detect abnormalities in plant equipment such as the process control objects. Plant maintenance engineers work to ensure that the process is running as uninterrupted and smooth as possible. It is of highest importance for them to be able to predict and detect any malfunctions in the plant. Issues must be corrected as soon as possible to minimize disturbances to the process. When a plant maintenance engineer detects and identifies a problem it is equally important to be able to correctly

diagnose the problem and perform the necessary repairs. It has been confirmed in user studies that plant maintenance engineers use the generated sound from the industrial equipment to detect abnormalities as some of these objects sound different when there is need for maintenance. For that reason audio is a powerful instrument to recognize upcoming problems. This however requires the plant maintenance engineer to be

experienced in order to be able to detect the sounds that can indicate an upcoming malfunction. However, not all maintenance engineers are that experienced,

As a result there is a strong need for a tool to help every maintenance engineer, regardless of their

experience level, to detect upcoming problems based on sounds .

However, there are a number of problems associated with the manual detecting of sounds.

• It takes lots of experience to be able to detect errors in equipment using hearing. Only few plant maintenance engineers are able to detect errors and this may be a growing problem as those experienced plant maintenance engineers may be close to retiring.

• Plant maintenance engineers often need to wear ear protection as noise levels are very high in the plant. This can affect their ability to detect sounds that indicate problems with the equipment. However these sounds can be an important source of information as they can indicate problems in the equipment. · The plant maintenance engineers have to remember how different equipment should sound and then try to compare that with how the equipment sounds at the moment. This can lead to very subjective

conclusions .

• Some sounds differ from one day to another.

These differences may be too hard to detect even for the most experienced plant maintenance engineer. The present invention provides a way to use automatic comparisons of sounds in order to detect abnormalities in process equipment. The detection is furthermore carried out with a minimum of interaction with the maintenance engineer, which simplifies and speeds up the work of the maintenance engineer.

Plant maintenance engineers will use their wireless terminals equipped with microphones to record sounds from process control objects. The captured sound of a process control object may then be compared with earlier recordings when this process control object was known to be functional. Through the comparison it will then be possible to detect signs of abnormalities. Some aspects of the invention are directed towards a sound processing arrangement comprising a sound

recording unit and a detecting unit, which detecting unit is in some variations of the invention a

positioning unit. In some aspects the sound processing arrangement also comprises a sound analysing unit.

The sound recording unit is in embodiments of the invention provided through the combination of recording controller 36 and microphone 35.

In some embodiments of the invention the positioning element 37 of the wireless terminal 32 forms a

positioning unit. In other embodiments the positioning block 21 of the sound handling server 23 forms a positioning unit. In some embodiments the sound handling element 38 of the wireless terminal 32 forms a sound analysing unit. In other embodiments of the invention, the sound handling block 22 of the sound handling server 23 forms a sound analysing unit.

It should be realized that a sound processing

arrangement may be provided through any combination of the above-mentioned sound recording unit with

positioning unit and possibly also sound analyzing unit .

In this first embodiment the positioning block 21 of the sound handling server 23 keeps track of the users and their positions in the plant 10. In this first embodiment of the invention, the positioning block 21 of the sound handling server 22 therefore forms a positioning unit of the sound processing arrangement. Furthermore, the positioning element 37 of the memory 39 in the wireless terminal 32 may be omitted in this embodiment .

The sound handling server 22 may obtain the position of the wireless terminal 32. This position may be obtained via the wireless network WN. The position of the wireless terminal 32 may more particularly be obtained through knowledge of which wireless access point 46, 48, 50 and 52 it is in contact with. The signal

strength of the communication between the wireless terminal and access point may be used to determine the distance between the wireless terminal and the access point, which gives a radius around the access point at which the wireless terminal may be located. This together with knowledge of the layout of the premises, such as where walls, floors and ceilings are provided, may be used for estimating the position. Furthermore, if a wireless terminal is in contact with more access points, then triangulation may be used. Here the points of intersection of the radiuses of two or three access points may be used for determining the position. Also this may be combined with knowledge of the layout of the premises in order to determine the position of the wireless terminal. The positioning block 21 of the sound handling server 23 may also have knowledge of the positions of the process control objects. The

positioning block 21 may thereby have knowledge of the positions of the various objects in the premises such as the positions of process control objects, like the first process control object 24.

The user 54 of the wireless terminal 32 is initially in some other location of the premises than the first room.

During an inspection of the plant the user 54 may move through the premises 45 and may then also enter the first room. The position of the wireless terminal 32 may then be continuously reported to the positioning block 21 of the sound handling server 23. The

positioning block 21 may now detect that the user 54 with his or her wireless terminal WT 32 moves to in the proximity of the first process control object 24, step 56, i.e. in proximity of the motor M. This may be done through detecting that the wireless terminal moves to within the area A, i.e. to within a radius r of the first process control object 24. When this happens the positioning block 21 may send an instruction, via the gateway 16 and wireless network WN to the recording controller 32 of the wireless terminal 32 that sound is to be recorded.

This instruction is then received in the wireless terminal 32 by the radio communication unit 42 via the antenna 44 and forwarded to the recording controller 36 of the sound recording unit. The sound recording unit then records sounds RS of the first process control object 24, step 58, which is done through the recording controller 36 receiving sounds from the microphone 35. The sounds are thereby recorded automatically as the user moves to within proximity of the first process control object 24. The sounds are thus recorded based on the detection of the wireless terminal 32 being in the proximity of the first process control object 24. The recording is thus triggered by the detection. The positioning block 21 of the server 23 may in a similar manner detect that the user is leaving the proximity of the first process control object, step 60, i.e. it may detect that the user leaves the above mentioned area A defined by the radius around the object 24. When this happens the positioning block 21 may send an instruction, via the gateway 16 and the wireless network WN, to the sound recording unit of the wireless terminal 32 that sound recording is to be stopped. Alternatively recording may be automatically stopped by the sound recording unit after a recording time out period has elapsed. If an instruction is sent, this instruction is then received by the radio communication unit 42 via the antenna 44 and forwarded to the recording controller 36 of the sound recording unit. The sound recording unit then ends or stops the recording of sounds, step 62, which may be done through the recording controller 36 stopping to receive sounds from the microphone 35. The recording of sound may thus be stopped based on the detection that the wireless terminal 32 leaves the proximity of the first process control object 24. In this way a sound recording RS has been made, for instance in the form of a locally created sound file, which is then provided to a sound analyzing unit, step 64. In this first embodiment the sound analyzing unit is provided in the sound handling server 23. The sound handling block 22 more particularly forms the sound analyzing unit. For this reason it should also be realized that in this first embodiment the sound handling element 38 may also be omitted from the memory 39 of the wireless terminal 32.

The recording controller 36 of the sound recording unit therefore sends the recorded sound RS to the sound handling block 22 of the sound handling server 23 using the radio communication unit 42, antenna 44 and

wireless network WN.

The recorded sound RS is then received by the sound handling block 22 in the sound handling server 23 via the gateway 16 and wireless network WN. In the sound handling block 22, the recorded sound RS is compared with at least one reference sound. In this embodiment it is compared with a healthy reference sound HRS, step 66, e.g. with a sound file, which may be a recording of the first process control element 24 when functioning properly. The healthy reference sound HRS is thus the sound that the first process control object 24 emits when it is healthy.

If there is a match, step 68, then the first process control object 24 is deemed healthy, step 70, while if there is no match, step 68, the sound analyzing unit continues and compares the recorded sound RS with another type of reference sound, malfunction reference sound MRS, step 72. There may here exist a number of different such sounds for a number of different types of malfunctions that the process control object 24 may experience. If there is now a match, step 74, then the type of malfunction MF that corresponds to the

malfunction reference sound MRS is indicated, step 76. This indication may be sent to the wireless terminal 32 of the user 54 and may furthermore be presented on the display 34. The user 54 may then take appropriate action, such as repair the process control device.

If there is no such match, step 74, then the sound analyzing unit may store the sound recording RS as a new or further malfunction reference sound MRS, step 78, and may also indicate that the fault is unknown, step 80. Also this indication may be sent to the wireless terminal 32. If the type of malfunction is new, the maintenance engineer 54 may now inspect the process control object 24 and see what kind of malfunction it is. This type of malfunction may thereafter be reported back to the sound analyzing unit, where it is linked to the new malfunction reference sound for later use.

It can in this way be seen that sound of the process control object 24 is automatically recorded and

analyzed as the maintenance engineer 54 moves in the proximity of it. The same procedure can then be applied in a similar manner for all process control objects. In this way it is possible to perform automatic

diagnosis of the process control objects using sound as the maintenance engineer moves through the plant.

The invention has a number of further advantages. · The use of a sound analyzing unit instead of human evaluation provides better diagnostics of the process control device. This will in turn result in improved preventive maintenance, which will increase the productivity in the plant as unexpected production shutdowns can be minimized.

• Plant maintenance engineers will be more effective as they need only concentrate on the results of the analysis and not the activity of recording of sound as such. The plant maintenance engineer may now further be inexperienced.

• When a sound deviation is found it is possible to automatically scan the sound history of the process control object to find any earlier reported deviation that seems to have the same pattern. If found, the plant maintenance engineer can now check how this issue was solved earlier, and in many cases solve the problem much quicker.

• The invention also provides the plant

maintenance engineers with an effective tool to help him or her make objectively based diagnostics which will result in preventive maintenance that avoids production stops.

• There is no need to install separate audio sensors on every process control object. The wireless terminals can in many cases replace these sensors and therefore substantially cut the costs for the feature of recording audio in devices.

Imagine the following scenario: 1. As seen in Figure 5, the plant maintenance engineer 54 performs the weekly inspection of the motors in the plant. He or she routinely moves with his or her wireless terminal 32 close to every motor to get a sound sample from the device. A sound sample is then automatically obtained as the maintenance engineer gets close to the object 24.

2. This sound sample is immediately uploaded to the dedicated sound analyzing unit.

3. The sound analyzing unit then analyzes and compares the recorded sound RS with earlier recordings, like the healthy reference sound HRS . The sound

analyzing unit may then detect an abnormality or deviation DEV from an earlier snapshot and conclude that there is an abnormality in the equipment. 4. The result may then be compared with earlier recordings, i.e. with malfunction reference sounds to detect if the deviation has been seen before. These recordings may be provided in a library of reference recordings for the object, which library may also comprise state information about object states, such as various fault states, associated with the recordings.

5. The sound analyzing unit may then note that a similar deviation was detected earlier, like 2 years ago.

6. As seen in Figure 6 the sound analyzing unit may return a report to the wireless terminal 32, which report may comprise a deviation diagram. This diagram may be accompanied by information that the deviation DEV between the recorded sound RS and the healthy reference sound HRS also was detected when uploaded from the wireless terminal earlier, like 2 years ago.

7. The maintenance engineer may then review the report and may thereafter report the problem to

management.

8. The maintenance engineer can now continue the inspection of the remaining motors, knowing that the manager will read the error report and assign someone to fix the problem. 9. The assigned person to fix the problem may handle the issue with the help of the input from the maintenance engineer regarding the earlier similar case . There are a number of different variations that are possible to make of the invention apart from those already mentioned. The positioning unit may be provided in the wireless terminal. The positioning element in the memory of the wireless terminal may thus provide the positioning unit. In this case the positioning element may determine that the wireless terminal is at a certain location through communication with the access points in the building and knowledge about the positions of these. The positioning unit may also be a Global Positioning System (GPS) unit obtaining the position through communicating with a GPS satellite. This positioning unit may then also know of the

positions of the process control objects.

The determination of if a wireless terminal is in the proximity of an object may differ between different process control objects. Some may be louder and

therefore the radius used may be larger than for some other process control objects. It is furthermore possible that the starting and possibly also the ending of recording is determined based on a sound level. If for instance the wireless terminal is found to be near a certain process control object, then recording may be started when the microphone detects that certain sound pressure level is exceeded and recording of the sound may be ended if the sound pressure falls below the same or another sound pressure level. However, it is also here possible with recording being ended after a time out. It can thereby be seen that the sound recording unit may assist in the detecting that that the wireless terminal is in the proximity of a process control object through detect sounds exceeding a first sound pressure level and that it may assist in the detecting that the wireless terminal leaves the proximity of process control object through detecting sounds falling below the first or another sound pressure level.

It is furthermore possible that the sound analyzing unit is provided in the wireless terminal, in which case the sound handling element of the wireless terminal memory may form a sound analyzing unit. In this case the sound handling element may receive reference sounds from the sound handling server, and perform and indicate comparisons as well as report results to the sound handling block of the sound handling server. There may as an alternative be stored a number of reference sounds in the wireless terminal for the sound handling element to use. Reporting may furthermore be performed after an inspection round is finished . The sound processing arrangement of the invention comprises the wireless terminal with sound recording unit. The sound processing arrangement also comprises the positioning unit, which may thus also be provided in the wireless terminal. However the sound analyzing unit may be omitted from the sound processing

arrangement. For this reason the sound processing arrangement may be configured to send sounds to a sound handling device that comprises the sound analyzing unit, which sound handling device may be implemented through the sound handling server.

The sound processing arrangement may also comprise the sound analyzing unit, for instance in the form of the sound handling element of the wireless terminal. In this case the sound handling arrangement may receive the at least one reference sound from a sound handling device, which may again be provided through the sound handling server.

The detection that a wireless terminal is in proximity of a process control object may also be made by the process control object itself. It may detect that a wireless terminal is in the proximity and order it to record sounds. Thereby the detecting unit of the sound processing arrangement may also be a sensor provided in the process control object. The positioning unit, sound analyzing unit and

recording controller may all be provided in the form of one or more processors together with computer program memory including computer program code for performing their functions. As an alternative they may be provided in the form of one or more Application Specific

Integrated Circuits (ASIC) or Field-Programmable Gate Arrays (FPGA) . This computer program code may also be provided on one or more data carriers which perform the functionality of the present invention when the program code thereon is being loaded into one or more devices implementing the sound processing arrangement, such as the sound handling server and/or the wireless terminal. One such data carrier 82 with computer program code 84, in the form of a CD ROM disc, is schematically shown in fig. 8. Such computer program may as an alternative be provided on another server and downloaded therefrom into the presentation control server and/or the mobile terminal . The invention can be varied in many more ways than the ones already mentioned. It should therefore be realized that the present invention is only to be limited by the following claims.