WO2022063674A1

WO2022063674A1 - Method and arrangement for controlling material treatment

Info

Publication number: WO2022063674A1
Application number: PCT/EP2021/075480
Authority: WO
Inventors: Dragos Dancila; Kristiaan PELCKMANS
Original assignee: Percyroc Ab
Priority date: 2020-09-25
Filing date: 2021-09-16
Publication date: 2022-03-31
Also published as: EP3975665A1

Abstract

A method (100), an arrangement (200) and a program are provided for processing an item (215). The arrangement comprises a source (210) for emitting electromagnetic radiation towards an item, a sensor (220) for sensing a temperature distribution of the item, and a controller (230) coupled to the source and sensor. The method comprises the steps of: providing (110) a collection of n parameter settings, BB, of the source, providing (120) a vector, p, and controlling (130) a setting of the source by selecting (140) a parameter setting in the collection of parameter settings, BB, based on a predetermined criterion of the vector, p; applying (150) the selected parameter setting via the controller for operating the source for emitting electromagnetic radiation towards the item, and updating (160) the vector, p, as a function of the temperature distribution of the item sensed by the sensor, until a predetermined threshold has been reached.

Description

METHOD AND ARRANGEMENT FOR CONTROLLING MATERIAL TREATMENT

FIELD OF THE INVENTION

The present invention generally relates to manufacturing methods, processes and/or arrangements using electromagnetic technologies such as radio-frequency (RF) and/or microwave (MW) energy for material treatment or processing and advanced manufacturing.

BACKGROUND OF THE INVENTION

Presently, there are numerous methods, processes and arrangements for material processing, including heating and/or curing of materials.

In the field of material curing, traditional heating tools integrated in large autoclave installations are often used to achieve this particular processing of the material. However, the purchase, operation and maintenance of such autoclaves may amount to a significant investment for the company in charge. For example, the operation time of such installations may imply a relatively large energy consumption. Hence, there is a wish to provide alternatives to processing of materials using autoclave installations, as the operation of these installations may be cost- and/or energy inefficient.

In the field of heating, electronic ovens are ubiquitously used. The electronic ovens heat items within a chamber by exposing materials to electromagnetic radiation. In the case of microwave ovens, the radiation most often takes the form of electromagnetic waves characterized by a specific frequency and amplitude. The waves within the microwave oven reflect within the chamber and cause standing waves, resulting from the waves with identical frequency and amplitude interfering with each other. The standing waves create nodes, being the positions on the standing waves where the waves stay in a fixed position over time because of destructive interference. The standing wave further creates antinodes, being the positions on the standing wave where the wave vibrates with a maximum amplitude. Due to the fact that no energy is delivered at the nodes whereas the maximum energy is delivered at the antinodes, the heating becomes uneven.

The problem of uneven or non-homogeneous heating of materials is addressed e.g. in US 2018/0098381 AL The document describes approaches which apply energy to an arbitrary item placed in a chamber for heating using evaluative feedback or deterministic planning to thereby solve the problem of uneven heating in an electronic oven. In some approaches, the evaluative feedback involves an evaluation of the item by sensing a surface temperature distribution for the item using an infrared sensor which is given to a control system. In some approaches, the evaluative feedback involves an evaluation of the item by sensing RF parameters associated with the application of energy to the item such as an impedance match or return loss. In some approaches, the deterministic planning is conducted using an evaluation of the parameters as implemented. For example, the deterministic planning can be guided by an evaluation of the surface temperature distribution of the item. The evaluation of the surface temperature distribution can be conducted during a discovery phase, which is conducted ex ante to the actual execution of a plan developed by such a deterministic planner, for purposes of obtaining information that can be used to generate that plan. The evaluation of the surface temperature distribution can also be conducted during execution of the plan to determine if the actual heating of the item is not progressing in accordance with what was expected when the plan was generated.

However, it should be noted that techniques and methods which are different compared to the method described in US 2018/0098381 Al for the purpose of trying to achieve an even or homogeneous heating of material are of interest.

Hence, there is an interest to improve methods and arrangements of the prior art in order to provide efficient methods and arrangements for material processing, and in particular for the purpose of obtaining a desired heating and/or curing of materials, advanced manufacturing and/or material treatment.

SUMMARY OF THE INVENTION

Hence, it is of interest to provide efficient methods and arrangements for material processing, such as material treatment. In particular, it is of interest to provide efficient methods and arrangements for the purpose of material processing, such as obtaining a desired heating and/or curing of materials relating to an even or homogeneous heating and/or heating of a certain (desired) location of the material.

This and other objects are achieved by providing a method, an arrangement and a program having the features in the independent claims. Preferred embodiments are defined in the dependent claims.

Hence, according to a first aspect of the present invention, there is provided a method for processing an item by an arrangement. The arrangement comprises at least one source for emitting electromagnetic radiation towards an item, at least one sensor for sensing a temperature distribution of the item, and a controller coupled to the at least one source and the at least one sensor. The method comprises the step of providing a collection of n parameter settings, a beam book (BB), of the at least one source, wherein n is an integer and wherein the collection of parameter settings, BB, comprises a plurality of parameters of which each parameter is associated with a setting of the at least one source. The method further comprises the step of providing a vector, p, comprising a plurality of n entries, pi, wherein i=l, The method further comprises the step of controlling at least one setting of the at least one source by, iteratively, selecting a parameter setting in the collection of parameter settings, BB, based on at least one predetermined criterion of the vector, p; applying the selected parameter setting via the controller for operating the at least one source for emitting electromagnetic radiation towards the item, and updating the vector, p, as a function of the temperature distribution of the item sensed by the at least one sensor, until a predetermined threshold of the temperature distribution of the item is reached.

According to a second aspect of the present invention, there is provided an arrangement for processing an item. The arrangement comprises at least one source for emitting electromagnetic radiation towards an item, at least one sensor for sensing a temperature distribution of the item, and a controller coupled to the at least one source and the at least one sensor. The controller is configured to, based on a collection of n parameter settings, BB, of the at least one source, wherein n is an integer and wherein the collection of parameter settings, BB, comprises a plurality of parameters of which each parameter is associated with a setting of the at least one source, and a vector, p, comprising a plurality of n entries, pi, wherein i=l,

select a parameter setting in the collection of parameter settings, BB, based on at least one predetermined criterion of the vector, p; apply the selected parameter setting via the controller for operating the at least one source for emitting electromagnetic radiation towards the item, and update the vector, p, as a function of the temperature distribution of the item sensed by the at least one sensor, until a predetermined threshold of the temperature distribution of the item is reached.

According to a third aspect of the present invention, there is provided a program comprising readable code for causing a processor to carry out the steps of the method according to the first aspect of the present invention when the program is carried out on the processor.

Thus, the present invention is based on the idea of processing an item by controlling one or more radiation-emitting sources by a collection of parameter settings, or a so-called beam book, BB. The method selects or chooses an entry in the collection of parameter settings, and applies this selected parameter setting via the controller for operating the at least one source for emitting electromagnetic radiation towards the item. The control is in turn effected by a feedback of the temperature distribution of the item sensed by one or more sensors. By this concept of the method, arrangement and program according to the aspects of the present invention, a desired processing and/or treatment of materials, such as e.g. heating and/or curing of materials, may be obtained very efficiently.

The present invention is advantageous in that the method, arrangement and program provide a reliable processing (e.g. heating, plasma treatment, etc.) of the item, as the processing strategy is efficiently adjusted during execution of the process. More specifically, it should be noted that existing approaches in the prior art often use a feed-forward concept, which is proven to be problematic as pre-programmed strategies of this kind lead to unreliable results. In contrast, by the control scheme implemented in the present invention, a reliable and efficient processing of one or more items may be obtained. The present invention is further advantageous in that the real-time adjustment of the vector, p, upon which the parameter setting in the control scheme is based, according to the subject-matter of the independent claims, results in a reliable processing of the item(s), as the concept adapts to the current properties, settings and/or situation of the process. It should be noted that simulation results of e.g. heating and/or curing processes may differ significantly from real heating and/or curing processes. Hence, prior art approaches based on e.g. beamforming may yield unreliable results. In contrast, the control scheme via the collection of parameter settings according to the present invention is robust, as it functions properly also in case of an occurrence of uncertain variables and/or disturbances. Due to this robustness, a reliable and efficient processing, such as a heating of the item(s), is provided by the real-time control scheme of the present invention.

The present invention is further advantageous in that the control scheme via the collection of parameter settings (beam book) inhibits feedback instability. For example, whereas feedback instability may potentially lead to radiation exceeding predetermined limits, the concept of the present invention results in that predetermined radiation limits may not be exceeded.

According to the innovative concept of the present invention, only a single entry of the collection of parameter settings is applied, and it is not possible to implement parameter settings which are not encoded in the collection. It will be appreciated that this approach is different from more traditional methods of feedback control or adaptive control where such constraints are relatively difficult to implement. It will be appreciated that the technique of the present invention is related to methods of Model Predictive Control (MPC) which explicitly encode such constraints. However, the concept of the collection of parameter settings (beam book) of the present invention is more suitable for operation in settings involving relatively complex signaling. For example, the present invention is particularly suitable for processes wherein complexities of the process cannot be encoded as linear constraints, or wherein computation resources are restricted.

According to the subject-matter of the present invention, there is provided a method for processing an item by an arrangement. By the term “processing”, it is here meant a processing of an item via electromagnetic radiation. In particular, the term “processing” may refer to material treatment such as e.g. heating (warming) and/or curing of an item. It will be appreciated that by the term “item”, it is here meant substantially any kind of material, product, sample, etc., and that the item may take on different forms, shapes or configurations. The arrangement comprises at least one source for emitting electromagnetic radiation towards an item. Hence, the source(s) may constitute or comprise substantially any unit(s), emitter(s) or the like for emitting electromagnetic radiation. The arrangement further comprises at least one sensor for sensing a temperature distribution of the item. Hence, the sensor(s) may be or comprise substantially any sensor(s), element(s), probe(s) or the like for sensing, registering and/or measuring a temperature distribution of the item. The arrangement further comprises a controller coupled to the at least one source and the at least one sensor. By “controller”, it is here meant substantially any control unit, device, or the like, which is coupled to the source(s) for a control thereof, and that the sensor(s) is coupled to the controller via feedback. The method comprises the step of providing a collection of n parameter settings, BB, of the at least one source, wherein n is an integer and wherein the collection of parameter settings, BB, comprises a plurality of parameters of which each parameter is associated with a setting of the at least one source. Hence, the collection of parameter settings, BB, which also may be referred to as the beam book, is associated with the setting of the source(s). The method further comprises the step of providing a vector, p, comprising a plurality of n entries, pi, wherein i=l,

Hence, the number of n entries is the same as the n parameter settings, BB. The method further comprises the step of controlling at least one setting of the at least one source by, iteratively, performing certain steps. The method steps include selecting a parameter setting in the collection of parameter settings, BB, based on at least one predetermined criterion of the vector, p. Hence, via one or more predetermined (pre-selected) criteria of the vector, p, the parameter setting in the collection of parameter settings, BB, is selected. In other words, an entry of the collection of parameter settings, BB, is sampled according to the distribution of the vector, p. The method steps further comprise applying the selected parameter setting via the controller for operating the at least one source for emitting electromagnetic radiation towards the item. Hence, the source(s) are operated by means of the parameter setting in the collection of parameter settings, BB, which in turn is selected based on the predetermined criterion(s) of the vector, p. The method steps further comprise updating the vector, p, as a function of the temperature distribution of the item sensed by the at least one sensor. Hence, based on temperature distribution feedback by the sensor(s), the vector, p, is updated. The above-mentioned steps of selecting the parameter setting in the collection of parameter settings, BB, applying the selected parameter setting, and updating the vector, p, are performed until a predetermined threshold of the temperature distribution of the item has been reached (met, obtained or satisfied). By the term “threshold”, it is here meant a predetermined threshold or criterion. For example, the threshold may be based on a difference between a desired and a sensed (measured) temperature distribution of the item.

According to an embodiment of the present invention, the setting of the at least one source may comprise at least one of a frequency, phase and power of the electromagnetic radiation emitted from the at least one source during operation. Hence, the setting of the source(s) such as unit(s), emitter(s) or the like for emitting electromagnetic radiation, may comprise a setting of the frequency, phase and/or power of the emitted electromagnetic radiation of the source(s). The present embodiment is advantageous in that the exemplified settings of the source(s) may to an even further extent improve the processing of the item. According to an embodiment of the present invention, the collection of parameter settings, BB, may be a predetermined collection of parameter settings based on at least one of a calibration process of the arrangement and a simulation process of the arrangement. In other words, the collection of parameter settings, BB, may be a predetermined collection of parameters settings based on a calibration process and/or a simulation process of the arrangement. For example, the collection of parameter settings, BB, may be determined from a calibration process of the arrangement, which is advantageous in that the calibration process may comprise availability of real-time data. According to another example, the collection of parameter settings, BB, may be determined from a simulation process. It will be appreciated that the simulation process, e.g. comprising (extended) electromagnetic simulations, is advantageous in that the collection of parameter settings, BB, may be obtained in a time- and/or cost-efficient manner, without pre-exposing the materials.

According to an embodiment of the present invention, the at least one sensor comprises a camera. For example, the camera may be an analog camera, a digital camera, an infrared, IR, camera, or the like. By the term “infrared, IR, camera”, it is here meant a thermographic camera, a thermal imaging camera, or the like. Hence, the infrared, IR, camera is able to sense a temperature distribution of the item using infrared radiation. The present embodiment is advantageous in that the use of one or more cameras, such as infrared, IR, cameras, is particularly suitable for determining or estimating the temperature distribution of the heated item. In turn, this leads to an even further improved control of the processing of the item via the control scheme of the method.

According to an embodiment of the present invention, the at least one source may comprise an antenna configured to emit electromagnetic radiation in at least one of a radio frequency, RF, range of 30 kHz - 300 MHz and a microwave frequency, MW, range of 300 MHz - 300 GHz. Hence, the antenna(s) of the source(s) is (are) configured to emit electromagnetic radiation in a RF range and/or a MW range. The present embodiment is advantageous in that the electromagnetic radiation of the antenna(s) may be conveniently selected and/or adapted for the purposes of the method. For example, the radiation frequency of the antenna(s) may be selected and/or adapted to one or more properties of the item to be heated in the method.

According to an embodiment of the present invention, each entry, pi, of the vector, p, may satisfy pi G [0, 1] and wherein r” pi = 1. Hence, each entry, pi, of the vector, t—~ A p, may take on a value in the closed interval [0, 1], In other words, the vector, p, is a (distribution) vector with n (positive) entries, pi, in the closed interval [0, 1], Furthermore, the summation of all entries, pi, is 1.

According to an embodiment of the present invention, selecting the parameter setting in the collection of parameter settings, BB, may be performed randomly before a predetermined number of steps, n_s, of updating the vector, p, has been attained. In other words, in an initial phase of the method, and as long as a predetermined number of steps, n_s, of updating the vector, p, has not been attained or reached in the control loop, the selection of the parameter setting in the collection of parameter settings, BB, may be performed randomly.

According to an embodiment of the present invention, selecting the parameter setting in the collection of parameter settings, BB, may be based on the highest value of the entries, pi, of the vector, p. Hence, the highest value of the entries, pi, of the vector, p, may be determined, and the selection of the parameter setting may be performed according to that entry, pi.

According to an embodiment of the present invention, the step of providing the vector, p, may comprise initializing the vector, p, and wherein the step of updating the vector, p, may comprise updating the vector, p, at least based on an exponential function of the temperature distribution of the item sensed by the at least one sensor, and a normalization factor. Hence, the step of providing the vector, p, may, first comprise initializing the vector, p. Thereafter, the step of updating the vector, p, may comprise updating the vector, p, based on an exponential function of the temperature distribution of the item sensed by the sensor(s), and/or a normalization factor.

According to an embodiment of the present invention, the arrangement may further comprise an enclosure arranged to enclose the item, wherein the item may comprise at least one of carbon and graphite, and wherein the method may further comprise the step of providing a homogeneous electromagnetic energy density in the enclosure and in the item. The method may hereby constitute or comprise an exfoliation process of graphite into graphene of the item. The present embodiment is advantageous in that the provision of a homogeneous electromagnetic energy density in the enclosure of the arrangement and in the item results in a relatively high throughput and/or high yield of the process.

It will be appreciated that several embodiments of the arrangement of the second aspect of the present invention and the program of the third aspect of the present invention correspond to the described embodiments of the method of the first aspect of the present invention, and it is hereby referred to the above for the description of the embodiments and the advantages thereof.

Further objectives of, features of, and advantages with, the present invention will become apparent when studying the following detailed disclosure, the drawings and the appended claims. Those skilled in the art will realize that different features of the present invention can be combined to create embodiments other than those described in the following.

BRIEF DESCRIPTION OF THE DRAWINGS

This and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing embodiment(s) of the invention. Figs. 1 and 2 schematically show arrangements for processing an item according to an exemplifying embodiment of the present invention,

Fig. 3 schematically shows a feedback loop of the method according to an exemplifying embodiment of the present invention, and

Fig. 4 schematically shows a method for processing an item according to an exemplifying embodiment of the present invention.

DETAILED DESCRIPTION

Fig. 1 schematically shows an arrangement 200 for processing an item according to an exemplifying embodiment of the present invention. The arrangement 200 comprises one or more sources 210 for emitting electromagnetic radiation towards an item 215. It should be noted that the sources 210 are merely schematically indicated in their function, numbers, etc. For example, the arrangement 200 may comprise an arbitrary number of sources 210 for emitting electromagnetic radiation. The sources 210, such as unit(s), emitter(s) or the like, may comprise any components for the purpose of electromagnetic radiation emission, such as e.g. signal generators, (pre-) amplifiers, etc. The sources 210 further comprise antennas 300 configured to emit electromagnetic radiation in a radio frequency, RF, range of 30 kHz - 300 MHz and/or a microwave frequency, MW, range of 300 MHz - 300 GHz. The frequency emitted by the antennas 300 of the arrangement 200 may be selected and/or adapted for the purposes of the method and/or adapted to one or more properties of the item 215 to be heated in the method.

The arrangement 200 as exemplified in Fig. 1 comprises a first enclosure 240 (“exposure box”) in which the item 215 is arranged, such that the item 215 is subjected or exposed to the electromagnetic radiation from the sources 210 inside the first enclosure 240 during operation of the arrangement 200. The antennas 300 of the sources 210 project into the first enclosure 240, whereas the sources 210 are arranged outside the first enclosure 240.

According to an example, the item 215 may comprise carbon, graphite and/or derived components thereof, and the sources 210 may be configured to provide a homogeneous electromagnetic energy density in the first enclosure 240 and in the item 215. The arrangement 200 may hereby be configured to achieve an exfoliation process of graphite into graphene of the item 215. More specifically, microwave energy from the sources 210 may be applied to excite intercalant molecules that find their way into the graphite stacked layers of the item 215, which consequently causes the breakage of the Van der Waals forces’ bonds between successive layers of the item 215.

During operation of the arrangement 200, the item 215 is exposed to the electromagnetic radiation as emitted by the source(s) 210 via the antennas 300, and the item 215 is consequently heated. The item 215, which the arrangement 200 is arranged to heat, is merely schematically indicated in Fig. 1 for reasons of simplicity, and it will be appreciated that the innovative concept of the present invention may be applied to substantially any kind of item. Hence, the item 215 may constitute substantially any kind of material, product, sample, etc., and may take on different forms, shapes or configurations.

The arrangement 200 in Fig. 1 further comprises a sensor 220 for sensing a temperature distribution of the item 215. It will be appreciated that the number of sensors 220 of the arrangement 200 is arbitrary. Furthermore, the position of the sensor(s) 220 in the arrangement is arbitrary. Hence, the disclosure of the (single) sensor 220 and its position in the arrangement 200 is for illustrative purposes only and serves for an increased understanding of the operation of the arrangement 200. The sensor 220 may comprise or constitute a camera, such as an analog or digital camera, an infrared, IR, camera, or the like. The infrared, IR, camera may be a thermographic camera, a thermal imaging camera, or the like, for sensing the temperature distribution of the item 215 as a result of the electromagnetic radiation emitted towards the item 215 from the source(s) 210 via the antennas 300. The sensor 220 may furthermore, or alternatively, comprise or constitute a fiber-optic sensor, a thermocouple, etc.

Fig. 1 further shows a controller 230 of the arrangement 200. The controller 230, which is schematically indicated, is coupled to the sources 210 and is also coupled to the sensor 220 via feedback. The controller 230 is configured to control the processing (such as a heating) of the item 215 via the sources 210 and antennas 300 and the resulting temperature distribution of the item 215 sensed by the sensor 220, which is provided to the controller 230 via feedback. The control scheme of the controller 230 is based on a collection of parameter settings, or a so-called beam book, as further described in Fig. 3 and the associated text.

Fig. 2 schematically shows an arrangement 200 for processing an item 215 according to an exemplifying embodiment of the present invention. It should be noted that the arrangement 200 in Fig. 2 largely corresponds to the arrangement 200 according to Fig. 1, and it is hereby referred to Fig. 1 and the associated text for an increased understanding of the arrangement 200. In Fig. 2, the first enclosure 240 is arranged around the (other) components of the arrangement 200. The arrangement 200 further comprises a second enclosure 250 (“shielding box”) arranged to enclose the sources 210, the sensor 220 and the controller 230. As the sources 210 are arranged inside the first enclosure 240 according to this example, the second enclosure 250 is arranged to accommodate the sources 210 and is configured to protect/ shield the sources 210 from electromagnetic radiation.

Fig. 3 schematically shows a feedback loop of the method according to an example of the present invention. Fig. 3 corresponds to Fig. 1, albeit in a much more simplified form, wherein e.g. the sources, the item, and the sensor have been omitted for reasons of simplicity. The controller 230, which is coupled to the source(s) and the sensor(s) (not shown), is configured to perform a control based on a collection of n parameter settings, BB, of the at least one source, wherein n is an integer and wherein the collection of parameter settings, BB, comprises a plurality of parameters of which each parameter is associated with a setting of the at least one source. For example, the collection of parameter settings, BB, may comprise n parameter settings of which each parameter is associated with a setting of j sources. The setting of the source(s) may, for example, comprise a setting of the frequency, phase and/or power of the emitted electromagnetic radiation of the source(s). According to the example of the collection of parameter settings, BB, in Fig. 3, a,j denotes the parameter setting of the z-th entry associated to the /-th source.

The controller 230 in Fig. 3 is further configured to perform the control based on a vector, p, comprising a plurality of n entries, pi, wherein i=l,

Each entry, pi, of the vector, p, may fulfil pi G [0, 1], Furthermore, the vector, p, may be normalized such that r” pi = 1. Based on the collection of parameter settings, BB, and the vector, p, the I — 1 controller 230 is configured to select a parameter setting in the collection of parameter settings, BB, based on at least one predetermined criterion of the vector, p. The controller 230 may select the parameter setting in the collection of parameter settings, BB, randomly before a predetermined number of steps, n_s, of updating the vector, p, has been attained. Alternatively, the controller 230 may select the parameter setting in the collection of parameter settings, BB, based on the highest value of the entries, pi, of the vector, p. This selection of the controller 230, which is indicated by the arrow from the vector, p, to the collection of parameter settings, BB, results in a selected parameter setting. The controller 230 is further configured to apply this selected parameter setting for operating the source(s) for emitting electromagnetic radiation towards the item, which is indicated by the outgoing arrows from the controller 230 in Fig. 3. As a result of the temperature distribution of the item sensed by the sensor(s), provided as a feedback from the sensor(s) to the controller 230 as indicated by the arrow towards the controller 230 in Fig. 3, the controller 230 is configured to update the vector, p, as a function of this temperature distribution. It will be appreciated that the updating of vector, p, as a function of this temperature distribution may be performed in many different ways, e.g. dependently on one or more previously obtained vectors, p.

The controller 230 in Fig. 3 is configured to perform the above-mentioned sequence of steps (or loop) of selecting the parameter setting in the collection of parameter settings, BB, applying the selected parameter setting, and updating the vector, p, until a predetermined threshold of the temperature distribution of the item has been reached. For example, the threshold may be based on a difference between a desired temperature distribution of the item and a sensed (measured) temperature distribution of the item.

Table 1 describes an algorithm of the method and arrangement according to an exemplifying embodiment of the present invention. It should be noted that the algorithm may be constructed in many different ways, and hence merely represents an example of how the part of the control scheme of the method and the arrangement of the present invention may be implemented for an increased understanding. Table 1

(1) Initialize p° as p = 1/m for all i = 1, m. Set s = 0 andH° = 0

(2) for t = 1, 2, ...do

Reset _rj 0 for all i = 1, ...., m while max i r, < 1 do

At (1) in Table 1, the vector, p, is initialized. The index s is set to 0, and H represents a heat distribution of the item as observed by the sensor(s). At (2), the for loop starts for the time steps, t. A vector, r, is reset, and the while loop is performed until a predetermined criterion is fulfilled. In the while loop, the index 5 is increased in (3)(a). In (3)(b), the parameter setting in the collection of parameter settings, BB, is selected based on at least one predetermined criterion of the vector, p. The parameter setting in the collection of parameter settings, BB, may be selected randomly before a predetermined number of steps of updating the vector, p, has been attained. Alternatively, the parameter setting in the collection of parameter settings, BB, may be selected based on the highest value of the entries, pi, of the vector, p. In (3)(c), the temperature distribution, H, of the item sensed by the sensor is determined. In (3)(d), the parameter /; is updated as a function of an exponential function of a desired heat distribution, M, and the temperature distribution, H, of the item sensed by the sensor(s) at different indexes, 5. In (4), outside the while loop and within the for loop, the vector, p, is updated, wherein Nt is a normalization factor.

Fig. 4 schematically shows a method 100 for processing an item according to an exemplifying embodiment of the present invention. The method 100 is provided for processing an item by an arrangement comprising at least one source for emitting electromagnetic radiation towards an item, at least one sensor for sensing a temperature distribution of the item, and a controller coupled to the at least one source and the at least one sensor. The method 100 comprises the step of providing 110 a collection of n parameter settings, BB, of the at least one source, wherein n is an integer and wherein the collection of parameter settings, BB, comprises a plurality of parameters of which each parameter is associated with a setting of the at least one source. The method further comprises the step of providing 120 a vector, p, comprising a plurality of n entries, pi, wherein i=l,

The method further comprises the step of controlling 130 at least one setting of the at least one source by, iteratively, perform the following steps: selecting 140 a parameter setting in the collection of parameter settings, BB, based on at least one predetermined criterion of the vector, p; applying 150 the selected parameter setting via the controller for operating the at least one source for emitting electromagnetic radiation towards the item, and updating 160 the vector, p, as a function of the temperature distribution of the item sensed by the at least one sensor. The steps 140, 150, 160 of the method 100 are performed until a predetermined threshold of the temperature distribution of the item has been reached.

It will be appreciated that the method 100 may have several different applications in the semiconductor industry. Examples include etching or deposition of thin films using microwave plasmas, such as plasma-enhanced chemical vapor deposition (MW- PECVD or PECVD), sputtering processes, physical vapour deposition (PVD), reactive ion etching (RIE). More generally, the method 100 may be a microwave assisted process in the semiconductor industry. One or more of these applications include areas such as e.g. thin film deposition, etching, crystal growth, epitaxial growth, diamond, nanowires, graphene synthesis, etc.

The person skilled in the art realizes that the present invention by no means is limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. For example, the number of one or more components or parts of the arrangement 200, such as the source(s) 210, sensor(s) 220, etc., may be different than those depicted/described, and may furthermore, have different shapes, dimensions and/or sizes than those depicted/described.

Claims

1. A method (100) for processing an item (215) by an arrangement (200) comprising at least one source (210) for emitting electromagnetic radiation towards an item, at least one sensor (220) for sensing a temperature distribution of the item, and a controller (230) coupled to the at least one source and the at least one sensor, the method comprising the steps of: providing (110) a collection of n parameter settings, BB, of the at least one source, wherein n is an integer and wherein the collection of parameter settings, BB, comprises a plurality of parameters of which each parameter is associated with a setting of the at least one source; providing (120) a vector, p, comprising a plurality of n entries, pi, wherein i=l,

and controlling (130) at least one setting of the at least one source by, iteratively, selecting (140) a parameter setting in the collection of parameter settings, BB, based on at least one predetermined criterion of the vector, p; applying (150) the selected parameter setting via the controller for operating the at least one source for emitting electromagnetic radiation towards the item, and updating (160) the vector, p, as a function of the temperature distribution of the item sensed by the at least one sensor, until a predetermined threshold of the temperature distribution of the item has been obtained.

2. The method according to claim 1, wherein the setting of the at least one source comprises at least one of a frequency, phase and power of the electromagnetic radiation emitted from the at least one source during operation.

3. The method according to claim 1 or 2, wherein the collection of parameter settings, BB, is a predetermined collection of parameter settings based on at least one of a calibration process of the arrangement and a simulation process of the arrangement.

4. The method according to any one of the preceding claims, wherein each entry, pi, of the vector, p, satisfies pi G [0, 1] and wherein

pi = 1.

5. The method according to any one of the preceding claims, wherein selecting the parameter setting in the collection of parameter settings, BB, is performed randomly before a predetermined number of steps, n_s, of updating the vector, p, has been attained.

6. The method according to any one of claims 1-4, wherein selecting the parameter setting in the collection of parameter settings, BB, is based on the highest value of the entry, pi, of the vector, p.

7. The method according to any one of the preceding claims, wherein the step of providing the vector, p, comprises initializing the vector, p, and wherein the step of updating the vector, p, comprises updating the vector, p, at least based on an exponential function of the temperature distribution of the item sensed by the at least one sensor, and a normalization factor.

8. The method according to any one of the preceding claims, wherein the arrangement further comprises an enclosure (240) arranged to enclose the item and wherein the item comprises at least one of carbon and graphite, wherein the method further comprises the step of providing a homogeneous electromagnetic energy density in the enclosure and in the item.

9. An arrangement (200) for processing an item, comprising at least one source (210) for emitting electromagnetic radiation towards an item (215), at least one sensor (220) for sensing a temperature distribution of the item, and a controller (230) coupled to the at least one source and the at least one sensor, wherein the controller is configured to, based on a collection of n parameter settings, BB, of the at least one source, wherein n is an integer and wherein the collection of parameter settings, BB, comprises a plurality of parameters of which each parameter is associated with a setting of the at least one source, and a vector, p, comprising a plurality of n entries, pi, wherein i=l, ..., «; select a parameter setting in the collection of parameter settings, BB, based on at least one predetermined criterion of the vector, p; apply the selected parameter setting via the controller for operating the at least one source for emitting electromagnetic radiation towards the item, and update the vector, p, as a function of the temperature distribution of the item sensed by the at least one sensor, until a predetermined threshold of the temperature distribution of the item has been obtained.

10. The arrangement according to claim 9, wherein the setting comprises at least one of a frequency, phase and power of the electromagnetic radiation emitted from the at least one source during operation. 15

1 l.The arrangement according to claim 9 or 10, wherein the collection of parameter settings, BB, is a predetermined collection of parameter settings based on at least one of a calibration process of the arrangement and a simulation process of the arrangement.

12. The arrangement according to any one of claims 9-11, wherein the at least one sensor comprises a camera.

13. The arrangement according to any one of claims 9-12, wherein the at least one source comprises an antenna (300) configured to emit electromagnetic radiation in at least one of a radio frequency, RF, range of 30 kHz - 300 MHz and a microwave frequency, MW, range of 300 MHz - 300 GHz.

14. The arrangement according to any one of claims 9-13, further comprising an enclosure (240) arranged to enclose the item, wherein the item comprises at least one of carbon and graphite, and wherein the at least one source is configured to provide a homogeneous electromagnetic energy density in the enclosure and in the item.

15. A program comprising readable code for causing a processor to carry out the steps of the method according to any one of claims 1-8 when the program is carried out on the processor.