DE102018112618A1 - Method for identifying a field device for an augmented reality application - Google Patents

Abstract

The invention relates to a method for identifying a field device (FG) of automation technology by means of an operating unit (BE), wherein the operating unit (BE) has a camera (KA), in particular a time-of-flight camera, comprising: - emitting a Infrared radiation, wherein the infrared radiation is directed substantially to at least one two-dimensional, infrared-reflective (MU) pattern on the field device (FG); detecting a reflection of the infrared radiation on the at least one reflective pattern (MU) by means of the camera (KA); - converting the received reflected infrared radiation into a reflection image (RB), - comparing the reflection image (RB) with at least one identification pattern (IM) of a field device (FG); and - transmitting identification data associated with the identification pattern (IM) to the operating unit (BE) in the event that there is a match between the reflection image (RB) and the identification pattern (IM).

Description

The invention relates to a method for identifying a field device of the automation technology by means of an operating unit, wherein the operating unit has a camera, in particular a time-of-flight camera.

Field devices are already known from the prior art, which are used in industrial plants. Field devices are often used in automation technology as well as in factory automation. In principle, field devices are all devices that are used close to the process and that provide or process process-relevant information. For example, field devices are used to detect and / or influence process variables. Measuring devices or sensors are used to record process variables. These are used, for example, for pressure and temperature measurement, conductivity measurement, flow measurement, pH measurement, level measurement, etc. and record the corresponding process variables pressure, temperature, conductivity, pH value, level, flow etc. Actuators are used to influence process variables. These are, for example, pumps or valves that can influence the flow of a liquid in a pipe or the level in a container. In addition to the measuring devices and actuators mentioned above, field devices are also understood as remote I / Os, radio adapters or general devices which are arranged at the field level.

A large number of such field devices are produced and sold by the Endress + Hauser Group.

Field devices that are integrated into a new application of a process plant, or replacement field devices that replace an outdated or defective field device of an application must be adapted during commissioning specifically to the respective application of the field device in the measuring point. For this, these field devices are configured and parameterized during or after production. The configuration describes, on the one hand, the hardware-side configuration, which includes, for example, the flange material of a flowmeter, as well as the software-side configuration. Parameterization refers to the definition and definition of parameters with the aid of which the operation of the field device is set to the respective features of the application, for example the measuring medium.

Depending on the field device type, a field device may have several hundreds of different parameters to which parameter values are assigned in the course of commissioning. Nowadays the parameterization of a field device is done by means of software tools. The inputs of the parameter values are possible only text-based and require a technical understanding on the part of the operator.

In the prior art, methods have become known in which the parameterization of field devices is simplified by means of augmented reality methods. In such methods, a control unit with a camera and a display unit is used, which camera detects an object from the real world. The detected object is virtually superimposed on the display unit of the operating unit with virtual components, which facilitate the parameter setting for the user, or submit parameter suggestions to the user on the basis of detected / detected gemoemtria of the measuring point in which the respective field device is installed. Examples of suitable control units are data glasses such as Microsoft Hololens or mobile devices such as tablets or smartphones.

The prerequisite for such augmented reality applications is, on the one hand, that it must be known which type of object is being recorded. On the other hand, the position of the object in three-dimensional space must be known in order to allow a correct overlay of the detected object with the virtual components. Augmented reality devices usually work with so-called 3D depth sensors to capture their environment three-dimensionally. From the depth information, a so-called 3D mesh (model) is generated at runtime, which maps the surfaces of the real environment. Based on this, applications can now superimpose real-world virtual content.

However, the resolution of the 3D depth sensors used is very inaccurate - for example, only relatively coarse structures, for example greater than 15 cm, can be detected. As a result, it is not possible, for example, to detect a field device mounted on a tank.

Based on this problem, the invention has the object to introduce a method which improves the identification of a field device for augmented reality applications.

• - Emittieren einer Infrarotstrahlung, wobei die Infrarotstrahlung im Wesentlichen auf ein am Feldgerät angebrachtes zweidimensionales, im Infrarotbereich reflexives Muster gerichtet ist;
• - Erfassen einer Reflexion der Infrarotstrahlung an dem reflexiven Muster mittels der Kamera;
• - Umrechnen der aufgenommen reflektierten Infrarotstrahlung in ein Reflexionsbild;
• - Vergleichen des Reflexionsbilds mit zumindest einem Identifikationsmuster eines Feldgeräts; und
• - Übermitteln von mit dem Identifikationsmuster verknüpften Identifikationsdaten an die Bedieneinheit, im Falle, dass eine Übereinstimmung zwischen dem Reflexionsbild und dem Identifikationsmuster besteht.

The object is achieved by a method for identifying a field device of automation technology by means of an operating unit, wherein the operating unit has a camera, in particular a time-of-flight camera, comprising:

• Emitting infrared radiation, the infrared radiation being directed substantially to a two-dimensional, infrared-reflective pattern applied to the field device;
• - Detecting a reflection of the infrared radiation on the reflective pattern by means of the camera;
• - converting the received reflected infrared radiation into a reflection image;
• Comparing the reflection image with at least one identification pattern of a field device; and
• - Transmitting associated with the identification pattern identification data to the operating unit, in the event that there is a match between the reflection image and the identification pattern.

The advantage of the method according to the invention is that the identification of a field device is improved by means of an augmented reality control unit. On the part of the field device no active components are needed for the identification. Due to the infrared radiation emitted by the operating unit, identification of the field device under poor lighting conditions is also possible.

The reflective pattern is, for example, a sticker which is applied to a defined location of the field device.

The reflection image is compared by means of image processing algorithms with known identification patterns. In particular, AI ("artificial intelligence") algorithms or neural networks are used here. By means of these algorithms, a known shape of the reflection image can be reliably detected even if the reflection image has a high degree of distortion due to the angle from the camera to the reflective pattern.

Field devices which are described in connection with the method according to the invention have already been mentioned by way of example in the introductory part of the description.

According to a preferred embodiment of the method according to the invention, it is provided that the infrared radiation is emitted by the operating unit, in particular by the camera. In this case, it is provided in particular that the reflective pattern is a retroreflective pattern. This means that the incident infrared radiation is largely reflected largely in the direction of the emission source, largely independent of the position of the emission source of the infrared radiation.

According to an advantageous development of the method according to the invention, it is provided that a perspective distortion of the reflection image is determined in comparison to the matching identification pattern, wherein the distortion is determined for both dimensions of the reflection image. For this purpose, the image processing algorithms described above are used. After a coincidence of the reflection image with a known identification pattern has been determined, the dimensions of the reflection image and the identification pattern are compared with each other. Since the respective identification pattern is known in its canonical form, this is used as a reference object.

A preferred embodiment of the method according to the invention provides that a relative position, in particular a relative angle of inclination, of the field device to the operating unit is determined on the basis of the determined perspective distortion. For this purpose, it is imperative that it is known at which point the reflective pattern is mounted on the field device. The position and position of the reflective pattern to the operating unit is transmitted in location coordinates of a relative coordinate system of the operating unit.

An advantageous embodiment of the method according to the invention provides that the operating unit determines an absolute position of the operating unit in three-dimensional space by means of position sensors. In addition, the operating unit can determine their respective location position, for example by means of GPS sensors.

According to a preferred embodiment of the method according to the invention, it is provided that an absolute position of the field device in three-dimensional space is calculated by comparing the relative position of the field device to the operating unit and the absolute position of the operating unit in three-dimensional space. By determining the absolute position of the operating unit in three-dimensional space, the operating unit defines an absolute coordinate system. The spatial coordinates of the reflexive pattern are then transformed into the absolute coordinate system.

According to an advantageous embodiment of the method according to the invention, it is provided that in the comparison of the reflection image to a database, in particular to a cloud-capable database, which accesses the at least one identification pattern. It is provided in particular that a plurality of identification patterns is stored in the database. It can be provided here that a different form of identification pattern is provided for each field device type.

Advantageously, it may additionally be provided that the reflective pattern contains additional shapes or areas, or symbols. These shapes or areas may be the serial number of the mapped to the respective field device and included in the identification.

According to a first variant of the method according to the invention, it is provided that data goggles are used as the operating unit. As an example of such data glasses is called the Microsoft Hololens. The data glasses have a display unit. In the simplest case, the display unit is a combined transparent glass with a projector. The operator looks through the glass. The environment viewed through the glass is called the field of vision. The projector is designed to project a projection on the glass which the operator perceives. Over the current field of view of the operator so the virtual objects can be placed. After determining the position from the field device to the data glasses, the virtual objects can now be laid over the field of view of the operator in such a way that they are located on or in the vicinity of the field device. If the position of the camera changes with respect to the field device, the image visualized on the display unit changes accordingly. However, the virtual objects remain in the assigned position of the field device and "wander", or rotate accordingly depending on the displacement of the field device on the image.

Alternatively, it is provided that the display unit as a field of view of the operator visualized by the camera, constantly updated image, and wherein the virtual objects overlay the image displayed on the display unit at least partially. The display unit of the control unit shows the live image, which is taken by the camera. The operator should direct the operating unit to the measuring point in such a way that the field device is detected by the camera. The virtual objects are placed over the current live image of the camera. This method is suitable for control units, which do not have transparent glass, but have a conventional display as a display unit.

According to a second variant of the method according to the invention, it is provided that a mobile terminal is used as the operating unit. A mobile terminal is in particular a tablet or a smartphone. For the visualization of virtual objects, the above variant is used with respect to a conventional display.

Alternatively, other types of devices can be used as operating units, insofar as they have a display unit and a camera, and can provide sufficient computing power.

• 1: ein Ausführungsbeispiel des erfindungsgemäßen Verfahrens.

The invention will be explained in more detail with reference to the following figures. Show it

• 1 : an embodiment of the method according to the invention.

In 1 is a measuring point MS a process automation system. The measuring point comprises a component KO in the form of a tank. At this tank KO is a field device FG mounted, which for detecting the level of the in the tank KO located process medium is used.

The field device must be commissioned FG be parameterized. The operator BD would like the parameterization of the field device FG using a virtual reality application. For example, the application should automatically detect relevant tank geometries and propose specific parameter values on this basis. The operator BD would like the virtual reality application on its control unit BE in the form of data glasses.

In order to be able to propose specific parameter values, the operating unit must BE be communicated to which type of field device FG it is about. In addition, in the virtual reality application may be special virtual objects, such as visualization models, or similar. used on the display unit AE the control unit BE are displayed and are specific to the particular field device type. Furthermore, it is necessary that the virtual reality application the positioning and location of the field device FG knows in three-dimensional space.

For this purpose, be on the field device FG at defined position one or more reflection images MU appropriate. These are retroreflective stickers with a defined shape.

For capturing the shape of the reflection image is a so-called time-of-flight camera KA used. This has a light source which emits infrared radiation. Based on the duration of the reflexive pattern MU reflected infrared radiation can be a 3D reflection image RM to be created.

Alternatively, a normal infrared camera KA which uses a two-dimensional reflection image RM detected.

The detected reflection image RM is received from the operation unit BE via internet to a database DB transmitted. Database DB has a plurality of pre-recorded identification pattern IN THE , which are each assigned to a corresponding field device type. By means of image processing algorithms, the captured reflection image RM with those in the database DB located identification patterns IN THE compared. Database DB executes the image processing algorithms and transmits the operating unit BE in case of a match identification information of the field device FG , for example the type of field device FG ,

Alternatively, it is provided that the operating unit BE the identification patterns IN THE from the database DB retrieves and executes the image processing algorithms themselves, using the identification patterns IN THE are associated with identification information of the corresponding field device type.

After the identification of the field device FG is completed, the absolute location of the field device FG determined in three-dimensional space. For this purpose, in a first step, a perspective distortion of the reflection image RM compared to the matching identification pattern IN THE determines the distortion for both dimensions of the reflection image RM is determined. For this purpose, new image processing algorithms described above are executed to determine a length deviation in both dimensions. Because the respective identification pattern IN THE is known in its canonical form, this is used as a reference object.

Based on the determined perspective distortion, in a second step, a relative position, in particular a relative angle of inclination, of the field device FG to the control unit BE determined. For this it is imperative that it is known at which point the reflexive pattern MU on the field device FG is appropriate. The position and location of the reflexive pattern MU to the control unit BE is transmitted in location coordinates of a relative coordinate system of the operating unit.

In a third step, the operating unit determines an absolute position of the operating unit by means of position sensors BE in three-dimensional space. The absolute position of the control unit BE includes the inclination of the operating unit BE and their respective location position, which detects the operating unit, for example by means of GPS sensors.

In a final step, the control unit determines BE by comparing the relative position of the field device FG to the control unit BE and the absolute position of the operating unit BE in three-dimensional space, the absolute position of the field device FG in three-dimensional space. By determining the absolute position of the operating unit BE in three-dimensional space defines the control unit BE an absolute coordinate system. The location coordinates of the reflexive pattern MU are then transformed into the absolute coordinate system and thereby the position of the field device FG , and possibly its position in relation to the control unit BE certainly.

Will be a time-of-flight camera KA used, the process can be abbreviated. The operating unit BE For this, it must determine its absolute position in three-dimensional space. Subsequently, the time-of-flight camera captures KA the distance of the control unit BE to the respective vertices of the reflexive pattern MU and then calculates the distance to the field device FG , or from this the absolute position and spatial position of the field device FG in three-dimensional space.

After the determination of the field device FG Completed in three-dimensional space, the actual augmented reality application can be on the control unit BE be performed, which, for example, to said application to assist the operator in the parameterization of the field device FG is.

As an alternative to a data goggles can serve as a control unit BE also a mobile terminal can be used. This is for example a smartphone or a tablet, but also a laptop with a webcam.

The method according to the invention is suitable for all types of field device types and is not limited to level measuring devices.

LIST OF REFERENCE NUMBERS

AE

display unit

BD

operator

BE

operating unit

DB

Database

FG

field device

IN THE

identification patterns

KA

camera

KO

Component of a measuring point

MS

measuring point

MU

reflexive pattern

RB

reflection image

Claims (9)

Method for identifying a field device (FG) of automation technology by means of an operating unit (BE), wherein the operating unit (BE) has a camera (KA), in particular a time-of-flight camera, comprising: - Emitting infrared radiation, wherein the infrared radiation is directed substantially to at least one two-dimensional, infrared-reflective (MU) pattern attached to the field device (FG); Detecting a reflection of the infrared radiation at the at least one reflective pattern (MU) by means of the camera (KA); - converting the received reflected infrared radiation into a reflection image (RB); Comparing the reflection image (RB) with at least one identification pattern (IM) of a field device (FG); and - transmitting identification data associated with the identification pattern (IM) to the operating unit (BE) in the event that there is a match between the reflection image (RB) and the identification pattern (IM). Method according to Claim 1 , wherein the infrared radiation from the operating unit (BE), in particular from the camera (KA), emitted. Method according to at least one of the preceding claims, wherein a perspective distortion of the reflection image (RB) is determined in comparison to the matching identification pattern (IM), wherein the distortion is determined for both dimensions of the reflection image (RB). Method according to Claim 3 , wherein a relative position, in particular a relative angle of inclination, of the field device (FG) to the operating unit (BE) is determined on the basis of the determined perspective distortion. Method according to Claim 3 or 4 , wherein the operating unit (BE) by means of position sensors determines an absolute position of the operating unit (BE) in three-dimensional space. Method according to Claim 5 in which, by comparing the relative position of the field device (FG) to the operating unit (BE) and the absolute position of the operating unit (BE) in three-dimensional space, an absolute position of the field device (FG) in three-dimensional space is calculated. Method according to at least one of the preceding claims, wherein in the comparison of the reflection image (RB) to a database, in particular to a cloud-capable database (DB), is accessed, which maintains the at least one identification pattern (IM). Method according to at least one of the preceding claims, wherein as a control unit (BE) a data glasses is used. Method according to at least one of Claims 1 to 7 , wherein as a control unit (BE) a mobile terminal is used.

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