Patent Description:
Producing more power using a wind turbine under given wind conditions can be achieved by increasing the size of the blades. However, the manufacture of wind turbine blades is becoming increasingly difficult for increasing blade sizes.

Wind turbine blades are manufactured from plies of fiber material which are infused with a resin and cured in a mold. With blades becoming larger and larger, the ply lay-up process is crucial with regard to process cost and time.

<CIT> discloses an apparatus for laying up a component by the assembly of fibrous tapes or fabrics, preimpregnated with resin, on a molding tool, in which the written instruction lists describing the manufacturing steps are replaced by projections of images on the tool which indicate to the operator the nature and the position of the cut-outs to be laid in succession.

<CIT> discloses a foreign object video detection system comprising a television camera for producing a digital color image of a work surface, a converter having direct memory access to a computer, color detection and color image processing software, logic for discriminating objects deemed to be a foreign object on the work surface or upon a layer of material on the work surface, logic for providing appropriate warning to the operator, and input controls for selecting the area of interest for detection and for optimizing the detection technique based upon the manufacturing situation.

It is one object of the present invention to provide a production system, method and computer program product providing
an improved approach towards producing a composite fiber component.

This object is achieved by the subject-matter defined in the appended independent claims.

Accordingly, there is provided a production system for producing a composite fiber component, in particular a wind turbine blade, as recited in claim <NUM>.

In this way, the ply lay-up process can be monitored and deviations can be detected easily and as they occur. The feedback is given to a worker who can then react accordingly, e.g. he or she can adjust a position of a ply. In embodiments, the feedback may also be given to a robot, the robot being controlled to perform the lay-up of plies. "Robot" herein includes any fully or partially automated device or machine.

The reference parameter may be an expected or target value. For example, the reference parameter is read from a storage device of the system. The reference parameter may be determined empirically, through modelling (i.e. simulation) or otherwise prior to operation of the system. The reference parameter, the comparative value and/or the given feedback or guidance may be improved through machine learning (using e.g. neural networks and/or deep learning) during the operation of the system.

"Plies laid on the working surface" herein is to be understood as plies lying directly on the working surface or indirectly with other plies, balsa wood or other materials placed in-between.

Preferably, the feedback is given in real-time. This is to say that the feedback is given substantially at the same time when the captured features change. For example, the feedback is given within less than <NUM> seconds, <NUM> seconds or <NUM> second from the change.

Preferably, the features are captured continuously as a respective ply is placed on the working surface.

"Working surface" is any surface configured to support the plies. The working surface may be a surface of a mold, mold portion, mandrel or any other tool, jig or fixture used in producing a composite fiber component. On the other hand, the working surface may also be formed by a part or component (in particular a precast or cured composite fiber component). For example, in this way repairs can be done on a composite fiber component that has already been produced and used in the field.

The plies comprise fiber material, e.g. carbon and/or glass fibers. The plies may be infused with a resin after the lay-up has been completed, or the plies may already comprise the resin at the point in time when they are laid on the working surface (e.g. prepreg material or pultruded, extruded or precast segments).

The computing device may comprise one or more microprocessors, memory (e.g. RAM, ROM), a hard disc (e.g. SSD) etc. In determining the parameter (in particular a position) of the captured features and comparing said parameter to a reference parameter (in particular a reference position), the color and/or location of captured pixels may be used. In particular, the computing device may generate a height-profile and/or 3D-profile of the volume of space above and/or including the working surface. In the case of lidar, for example, distances between the sensor and a respective object may be measured. The computing device may combine these distances to generate the height-profile and/or 3D-profile of the volume of space above and/or including the mold surface.

According to an embodiment, the optical device comprises a plurality of optical cameras and/or lidar sensors.

These types of sensors are well suited towards capturing optical features of the working surface or plies.

According to a further embodiment, the system includes a mold and the working surface is a mold surface, and/or the optical device captures features within a volume above and/or including the, preferably entire, mold surface.

, the mold surface may be comprised by a mold half. The mold may be configured to cure the plies using heat and/or pressure.

Preferably, the entire mold surface is monitored. In particular, the entire mold is monitored through the entire lay-up-process (i.e. from the first to the last ply being placed).

According to a further embodiment, the captured features comprise edges, material and/or defects of the plies, reference points on the working surface and/or foreign objects and/or the parameter includes a position (e.g. 3D-coordinates), geometry, color and/or texture.

Edges are particularly useful in determining the correct location of a respective ply. Further, the material (fibers, steel, wood) may be identified using, e.g., color. A "foreign object" is an object that is not to be combined with other parts to form the composite components to be produced. The computing device may be configured to determine that an object is a foreign object by (i) evaluating the comparative value (i.e. in particular evaluating the question of what the respective surface should look like without the object; therein, the parameters evaluated in respect of the object may be its position, geometry, color etc.) and/or (ii) evaluating contextual data for example relating to workers in the vicinity of the object. For example, if no worker interacts with an object that cannot be associated with any of the materials (plies, balsa wood etc.) making up the composite component to be produced or with the working surface itself for more than a predefined period of time (e.g., <NUM> minutes), then the computing device decides that the object is a foreign object. Foreign objects may be tools (e.g. scissors or washers) etc..

According to a further embodiment, the feedback includes a visual and/or acoustic feedback.

This feedback can be easily recognized by a worker operating on the working surface. In one embodiment, the feedback is provided through an augmented reality device (e.g. glasses) According to a further embodiment, the visual feedback includes a pattern of light projected on the working surface and/or on an upwardly exposed surface of a ply.

Thus, the mold surface and/or a ply that has already been placed is efficiently used as a screen.

As recited in claim <NUM>, the system includes a projector device for projecting a pattern of light on the working surface and/or on an upwardly exposed surface to guide placement of plies on the working surface and/or on the said ply.

For example, the pattern may include markings, symbols, letters, numbers etc. The projector device may be (at least in parts) identical to the feedback device. Besides guiding the worker, the projected pattern may also provide feedback. , the projected pattern may (i) indicate a target position of a ply (as described below) and (ii) blink or change color to include feedback (e.g. blinking in red meaning that the current and target position do not yet correspond). According to a further embodiment, the projector device including one or more lasers.

Thereby, the pattern can be generated easily.

According to a further embodiment, the pattern demarcates a target position of a ply to be placed on the working surface and/or on the upwardly exposed ply, said pattern preferably demarcating a target position of edges of the ply.

For example, the pattern may include markings (lines, triangles etc.) which indicate where edges of the plies should come to be arranged once the respective ply lies on the working surface (or on another pile).

According to a further embodiment, the system further comprises a control device, the control device being configured for controlling:.

For example, the system will only proceed to guide the workers towards placing the second ply if the position of the first ply is correct. Otherwise, the markings for the second ply will not show up on the first ply and/or other plies or the working surface.

Thus, each time a ply is placed, the system checks for any changes that may have occurred in the meantime on plies that have already been placed on the working surface or on other (free) portions of the working surface. This ensures that the lay-up is correct.

As recited in claim <NUM>, the system further comprising a control device, the control device being configured for controlling:.

Therefore, at least two teams can work in parallel. For example, the two teams can start from opposite ends of the component with laying the plies. This makes the lay-up process faster.

According to a further embodiment, the system further comprises a storage device for storing the captured features. In particular, all features captured during the lay-up process are stored. Thereby, a digital twin is produced which can be used later during fault-analysis, for example, during a service or after failure of the component, e.g. a wind turbine blade.

According to a further embodiment, the computing device uses a machine learning algorithm and/or uses edge computing. According to a further aspect, there is provided a method for producing a composite fiber component, in particular a wind turbine blade, as recited in claim <NUM>.

According to a further embodiment not covered by the appended claims, the method comprises the steps of:.

For example, the second pattern is only projected if the first ply is found to be in the correct position by way of the comparative result.

Thus, each time a ply is placed, the system checks for any changes that may have occurred in the meantime.

According to a further embodiment, the method comprises the steps of:.

Thereby, the lay-up work can be done in parallel.

According to a further aspect, there is provided a computer program product as recited in claim <NUM>.

A computer program product, such as a computer program means, may be embodied as a memory card, USB stick, CD-ROM, DVD or as a file which may be downloaded from a server in a network. For example, such a file may be provided by transferring the file comprising the computer program product from a wireless communication network.

The respective device, e.g. the optical, computing, control or feedback device, may be implemented - at least partially - in hardware and/or in software. If said device is implemented in hardware, it may be embodied as a computer or as a processor or as a part of a system, e.g. a computer system. If said device is implemented in software it may be embodied as a computer program product, as a function, as a routine, as a program code or as an executable object.

The embodiments and features described with reference to the system of the present invention apply mutatis mutandis to the method and/or computer program product of the present invention.

The person skilled in the art may also add individual or isolated aspects and features to the most basic form of the invention, the scope of h is defined by the appended claims.

<FIG> shows a production system <NUM>. The production system <NUM> includes a mold <NUM> having a mold surface <NUM>. The mold <NUM> - of which only one mold half is shown in <FIG> - is configured for manufacturing a composite fiber component, in the case of the example, a wind turbine blade.

To this end, plies <NUM> - <NUM> of fiber material are picked up by workers from a storage or cutting station (not shown) and laid on the mold surface <NUM> or on a ply that has previously been placed on the mold surface <NUM>. The fiber material may comprise, e.g., carbon fibers or glass fibers. In addition, balsa wood, foam or other materials (not shown) may be placed on the mold surface <NUM> or on existing plies.

Once all plies <NUM> - <NUM> (and balsa wood etc.) have been placed correctly in the mold <NUM>, the mold <NUM> is closed and a vacuum is created inside. Next, the plies <NUM> - <NUM> inside the mold <NUM> are infused with a resin and cured. The cured blade can then be removed from the mold <NUM>.

The plies <NUM> - <NUM> must be placed in the right locations inside the mold <NUM>. These locations are defined by a CAD (Computer Aided Design) model, for example. The CAD model contains 3D-coordinate data defining the layout of the plies and other materials. The CAD model is e.g. generated during the design phase of the blade. Therein, the plies and other materials have been arranged to obtain the desired blade properties, e.g. strength or weight.

The production system <NUM> is designed to guide the workers (or robots in other embodiments) when placing the plies <NUM> - <NUM> and also to give feedback to them. To this end, the production system <NUM> comprises an optical device <NUM> (<FIG>) having multiple cameras <NUM> (<FIG>). The cameras <NUM> capture, using CCD (charge coupled device) chips or the like, the volume <NUM> above and including the mold surface <NUM>. Instead or in addition to the cameras <NUM>, the optical device <NUM> may include lidar sensors (not shown).

Preferably, the cameras <NUM> cover the entire mold <NUM> or volume <NUM>. In the case of <FIG>, the cameras <NUM> will record the plies <NUM> - <NUM>, the free mold portion <NUM> as well as a pair of scissors <NUM> lying on the mold surface <NUM>. In particular, the cameras <NUM> capture features such as reference points <NUM> of the mold <NUM> as well as edges <NUM> of respective plies <NUM> - <NUM>.

Further, the production system <NUM> comprises a computing device <NUM> shown in <FIG>. The computing device <NUM>, for example a server including a plurality of GPUs (graphics processing units), is in data communication with IoT devices <NUM>. The IoT devices <NUM> include the optical device <NUM> as well as a combined feedback and projector device <NUM>.

Both, the computing device <NUM> and the IoT devices <NUM>, are located on the factory site <NUM> for minimal latency which will be explained in more detail. The computing device <NUM> is further in data communication with a data storage device <NUM> in the cloud <NUM>.

The computing device <NUM> uses machine learning, i.e. algorithms that improve automatically through experience (for example using deep learning and/or neural networks developed by labelling data sets), to analyze the data recorded by the cameras <NUM> in <FIG>. Therein, the features (in particular, the scissors <NUM>, the reference points <NUM> and edges <NUM>) are extracted (the extraction process may be error checked using chi squared statistical analysis) and associated with 3D-coordinates (also termed "determined parameter" herein). These actual coordinates are compared to target coordinates (also termed "reference parameter" herein) from the CAD model. The computing device <NUM> then yields a comparative result.

The productions system <NUM> of <FIG> further comprises an onsite control device <NUM> which, depending on the comparative result, gives instructions to the feedback and projector device <NUM>.

The feedback and projector device <NUM> comprises a number of lasers <NUM> as shown in <FIG>. The lasers <NUM>, controlled by the control device <NUM> (see <FIG>), projects visible markings <NUM> onto the ply <NUM> which has already been placed and onto the mold surface <NUM> indicating where the edges <NUM> of the ply <NUM> (also termed "kth pile" herein) should be arranged when the ply <NUM> is laid into the mold <NUM>. Once the ply <NUM> has been correctly placed (which is decided based on the comparative result mentioned above, i.e. when the actual and target coordinates agree), the control device <NUM> will control the lasers <NUM> to generate a green triangle <NUM> as shown in <FIG> (or any other useful pattern) on the correctly placed ply <NUM>. This gives the workers immediate feedback that the job is complete and that they can start with the next ply, for example. The lasers <NUM> will then proceed to generate markings <NUM> that will indicate the correct position of the next ply.

On the other hand, if the edges <NUM> of the ply <NUM> that has been placed do not correspond to the target positions from the CAD model, then the lasers <NUM> will show a red cross on ply <NUM>. Also, the control device <NUM> will control the lasers <NUM> not to show the markings <NUM> for the next ply to be placed until the position of the ply <NUM> has been corrected.

Also, when for some reason the ply <NUM> that has already been placed should move - for example with its edges <NUM>' - out of its correct position, this ply will be marked accordingly. For example, the control device <NUM> will control the lasers <NUM> to show the edge markings <NUM>' for this ply. This function is obtained through the control device <NUM> controlling the cameras <NUM> to continuously capture all features of the entire mold surface <NUM> as well as of all plies <NUM> - <NUM> (also termed plies "<NUM>st to kst" herein) and other materials on the mold surface <NUM> that have been placed until then.

Advantageously, since the computing device <NUM> uses edge computing the guidance or feedback to the user can be given in real time. Latency from the point in time when, for example, the position of a ply <NUM> - <NUM> changes until the guidance or feedback is produced by the lasers <NUM> is less than <NUM> or <NUM> seconds.

Another feature of the production system <NUM> is that the computing device <NUM> will also recognize any foreign objects such as the scissors <NUM> in <FIG> that have accidently been left on the mold surface <NUM>. The control device <NUM> will then control the lasers <NUM> to, for example, circle the foreign object with a red line of light (illustrated in <FIG> with a circle around the scissors <NUM>). This will avoid any foreign objects to become integrated into the finished blade, removal of which being expensive and detrimental to structural integrity of the blade. Similarly, the computing device <NUM> may be configured to spot defects as they occur in the plies <NUM> - <NUM> and other materials used to build the blade on the mold <NUM>. When such a defect is spotted, the control device <NUM> will control the lasers <NUM> to circle or otherwise highlight the defect.

Put more generally, the production system <NUM> is capable of spotting new 'anomalies' for categorization as accepted or not, thereby allowing for continuous learning. When the production system <NUM> registers something for the first time that looks abnormal, this is flagged to the production staff and forwarded to the quality department who can then allow this to be passed as acceptable or teach the system <NUM> that this should from now on be flagged as an error to be fixed.

As shown at the far end of <FIG>, there is a second team of workers laying the ply <NUM> simultaneous with the workers of the first team laying the ply <NUM>. Therein, markings (not shown) are also generated for the ply <NUM> (also termed "jth pile" herein) to guide the lay-up process. Thus, two or more teams can work in parallel in the production system <NUM> to build the blade in shorter time.

Also, the captured features (e.g. edges <NUM>) are stored in the data storage device <NUM> (see <FIG>). Based on the color, texture etc., the computing device <NUM> may also be configured to recognize the material of which the blade is made of. Thus, a digital twin of the blade produced may be generated and saved. This data can be accessed when, for example during the lifetime of the blade (e.g. in operation), problems occur and knowledge of the exact position of plies and other materials is needed.

<FIG> illustrates an embodiment of a method for producing composite fiber components, in particular wind turbine blades.

In step S1, features of the mold surface <NUM> (see <FIG>) and of plies <NUM> - <NUM> laid on the mold surface <NUM> are optically captured.

In step S2, a position of the captured features <NUM>, <NUM>, <NUM> and a comparative result depending on a comparison of the determined position (measured 3D coordinates) and a reference position (3D coordinates from CAD model or at least derived therefrom) is determined.

In step S3, feedback <NUM> (or guidance such as the markings <NUM> in <FIG>) is given to the workers depending on the comparative result in real time.

Claim 1:
A production system (<NUM>) for producing a composite fiber component, in particular a wind turbine blade, comprising:
a working surface (<NUM>);
an optical device (<NUM>) for optically capturing features (<NUM>, <NUM>, <NUM>) of the working surface (<NUM>) and/or of plies (<NUM> - <NUM>) laid on the working surface (<NUM>), said plies (<NUM> - <NUM>) comprising fiber material;
a computing device (<NUM>) for determining a parameter of the captured features (<NUM>, <NUM>, <NUM>) and a comparative result depending on a comparison of the determined parameter and a reference parameter;
a feedback device (<NUM>) configured to give feedback (<NUM>) depending on the comparative result;
a projector device (<NUM>) for projecting a pattern (<NUM>) of light on the working surface (<NUM>) and/or on an upwardly exposed surface of a ply (<NUM> - <NUM>) to guide placement of plies (<NUM> - <NUM>) on the working surface (<NUM>) and/or on said ply (<NUM> - <NUM>); and
a control device (<NUM>), characterized in that the control device is configured for controlling:
the projector device (<NUM>) to project a kth pattern (<NUM>) corresponding to a target position of a kth ply (<NUM>), and, at the same time, to project a jth pattern corresponding to a target position of a jth ply (<NUM>);
the optical device (<NUM>) for optically capturing features (<NUM>, <NUM>, <NUM>) of the kth and jth ply (<NUM> - <NUM>) laid on the working surface (<NUM>);
the computing device (<NUM>) for determining a position of the captured features (<NUM>) and a comparative result depending on a comparison of the determined position and a reference position for the kth and jth ply (<NUM>, <NUM>) respectively; and
the feedback device (<NUM>) to give feedback depending on the respective comparative result;
wherein k is incremented from <NUM> to N, with N designating the total number of plies (<NUM>, <NUM>) making up a first portion of the composite component to be produced, and j is incremented from <NUM> to M, with M designating the total number of plies (<NUM>, <NUM>) making up a second portion of the composite component to be produced.