T 1095/14 (Large-scale frame assembly/BOEING) of 23.9.2015

Summary of Facts and Submissions

I. The present appeal arises from the decision of the opposition division posted on 10 March 2014 revoking European Patent No. 1 719 030.

II. The opposition was based on the grounds for opposition pursuant to Article 100(a) EPC, in combination with Articles 52(1) and 54 and 56 EPC, and Article 100(c) EPC in combination with Article 123(2) EPC. The opposition division examined on its own motion the opposition ground pursuant to Article 100(b) EPC in combination with Article 83 EPC.

The opposition division came to the conclusion that, with respect to the main request, the invention was sufficiently disclosed for the skilled person to carry it out, that the independent claims 1 and 17 met the requirements of Article 123(2) EPC, and that, whilst being new over the cited prior art, the subject-matter of the independent claims 1 and 17 was not based on an inventive step (Articles 52(1) and 56 EPC).

Auxiliary request 1 was held not allowable due to a lack of inventive step (Article 56 EPC).

Auxiliary request 2 was held not allowable due to a lack of clarity (Article 84 EPC) and non-compliance with Article 123(2) EPC.

Auxiliary request 3 was held not allowable due to a lack of clarity (Article 84 EPC) and a lack of inventive step (Article 56 EPC).

III. Notice of appeal was filed against this decision by the patent proprietor (appellant). The appellant requested that the decision of the opposition division be set aside, that the case be remitted to the department of first instance, and that the appeal fee be refunded. Auxiliarily, the appellant requested that the decision be set aside and that the patent be maintained on the basis of claims of a main request or, in the alternative, on the basis of claims of a first or second auxiliary request, all filed with the statement of grounds of appeal. As an auxiliary measure, oral proceedings were requested.

IV. The respondents requested that the appeal be dismissed. Further, the respondents requested that the appellant's request for remittal to the department of first instance be dismissed. Oral proceedings were requested as an auxiliary measure.

V. In a communication pursuant to Article 15(1) RPBA accompanying a summons to oral proceedings the board gave its preliminary opinion.

VI. In reply to the summons, the appellant submitted with a letter dated 21 August 2015 an amended second auxiliary request as well as new third and fourth auxiliary requests and withdrew the first auxiliary request. Further, for the benefit of an employee of the proprietor, the appellant with another letter dated 21 August 2015 requested English interpreting during the oral proceedings in view of the fact that the respondents' representative had indicated to speak German.

VII. During the oral proceedings before the board, the appellant submitted two further versions of claims of a second auxiliary request, each time replacing the previous version of the second auxiliary request, and withdrew the request for interpreting as well as the requests for remittal to the department of first instance and reimbursement of the appeal fee. The appellant eventually, after also withdrawing the main request, requested that the decision under appeal be set aside and that the patent be maintained on the basis of claims of the second auxiliary request (labelled "adapted twice") as filed during the oral proceedings or, in the alternative, on the basis of claims of the third or the fourth auxiliary request, both filed with the letter dated 21 August 2015.

The respondents requested that the appeal be dismissed.

At the end of the oral proceedings, the chairman announced the board's decision.

VIII. Claim 1 of the second auxiliary request reads as follows:

"1.1 A method (400) of assembling first and second large-scale airframe components (102-108), comprising:

1.2 measuring (404) a first plurality of discrete point positions (116) associated with the first component (102-108) by using a first measurement system and/or measuring by scanning a first sampling surface position (124) by using a second measurement system, the first plurality of discrete point positions (116) being at least one of on and adjacent to the first component (102-108), wherein the first measurement system includes at least one of a global positioning system, an infrared global positioning system, and a laser-based point tracking system, and the second measurement system includes at least one of a radar system, a structured light measurement system, and a scanning system;

1.3 measuring by scanning (408) a second sampling surface position associated with the second component by using the second measurement system and measuring a second plurality of discrete point positions (116) associated with the second component (102-108) by using the first measurement system, the second plurality of discrete point positions (116) being at least one of on and adjacent to the second component;

1.4 comparing (410, 412) the measurements associated with at least one of the first and second components (102-108) with a desired position information, wherein the desired position information are as-designed positions of the first and second components, wherein the step of comparing includes applying a best fit routine to the measurements and the desired position information, the best fit routine being a surface fitting routine, the surface fitting routine depending on fitting criteria being weighted such that certain regions of the measured sampling surface position will be assigned more importance than other regions;

1.5 computing (420) a transformation matrix based on an output of the best fit routine thereby improving the comparison between the measurements and the desired position information; and

1.6 moving (424) at least one of the first and second components (102-108) according to the transformation matrix such that a best fit position between the measured sampling surface position and a desired surface position is provided."

Independent claim 15 of the second auxiliary request reads:

"17.1 A system for positioning first and second large-scale airframe components (102-108) for assembly, comprising:

17.2 a first measurement system (110) adapted to measure a plurality of discrete point positions (116) associated with at least one of the first and second components (102-108), the discrete point positions (116) being at least one of on and adjacent to the corresponding one of the first and second components (102-108), wherein the first measurement system includes at least one of a global positioning system, an infrared global positioning system, and a laser-based point tracking system;

17.3 a second measurement system (120) adapted to measure by scanning at least one sampling surface position (124) on at least one of the first and second components (102-108), wherein the second measurement system includes at least one of a radar system, a structured light measurement system, and a scanning system;

17.4 a data management device (118) operatively coupled to the first and second measurement systems (110, 120),

17.5.1 the data management device (118) including a processing portion adapted to receive the measured positions of the plurality of discrete points (116) and the at least one sampling surface position (124),

17.5.2 compare the measured positions with a desired position information of the at least one of the first and second components (102-108), wherein the desired position information are as-designed positions of the first and second components, wherein the step of comparing includes applying a best fit routine to the measurements and the desired position information, the best fit routine being a surface fitting routine, the surface fitting routine depending on fitting criteria being weighted such that certain regions of the measured sampling surface will be assigned more importance than other regions,

17.5.3 the processing portion is adapted to compute a transformation matrix based on a best fit routine thereby improving the comparison between the measured positions and the desired position information; and

17.6 a position control system (150) operatively coupled to the data management device (118) and adapted to move at least one of the first and second components (102-108) according to the transformation matrix such that a best fit position between the measured sampling surface and a desired surface position is provided."

In view of the board's decision it is not necessary to reproduce the claims of the third and fourth auxiliary requests.

Reasons for the Decision

1. Second auxiliary request: Admissibility

1.1 The question of admissibility of the present auxiliary request is linked to the admissibility of the second auxiliary request filed with the statement of grounds of appeal. The admissibility of the latter request is therefore considered first.

1.2 The respondents requested that the second auxiliary request as filed with the statement of grounds of appeal not be admitted, arguing that the patent proprietor had had the opportunity to submit this request during the opposition proceedings, thus implicitly referring to Article 12(4) RPBA, that the request did not constitute a response to the reasons for the decision under appeal, that it was not caused by the introduction of new facts, that it was not convergent due to the deletion of the feature "at least one of a first surface position" in point 1.2 of claim 1, and that in general the appeal procedure should be for checking the correctness of the first instance decision and not for allowing trial-and-error-based submissions of new requests.

1.3 In the board's view, the second auxiliary request filed with the statement of grounds of appeal constituted a fair attempt to overcome the inventive step objection raised by the opposition division (cf. point 6 of the decision under appeal) by more specifically defining in a convergent manner the features considered relevant to the question of inventive step. In particular, the independent claims 1 and 15 of this request specifically indicate that two different measurement systems are used in the measuring step 1.3. The appellant thereby rebutted the oppositions division's findings, which did not follow the proprietor's argument that a distinction was to be made between measuring a surface position on the one hand and measuring a plurality of discrete point positions on the other hand. Further, the deletion of "at least one of ..." in point 1.2 of claim 1 did not give rise to divergency, since it was compensated for by the introduction of "and/or" in the same feature. The alternative nature of the measuring of a first plurality of discrete point positions and the scanning of a first surface sampling position was therefore not affected by this amendment.

1.4 The board therefore concluded that the second auxiliary request filed with the statement of grounds of appeal constituted an admissible request.

1.5 The present second auxiliary request includes amendments with respect to the version as submitted with the statement of grounds of appeal. Its admissibility is subject to the board's discretion according to Article 13(1) RPBA.

The respondents argued that it was not convergent with respect to a previous version, in particular due to the deletion of the word "different" in point 1.2 of claim 1.

1.6 The word "different" was however deleted in response to a clarity objection raised by the board at the oral proceedings and compensated for by the explicit introduction of the two measurement systems, which led to a further narrowing of the scope of the independent claims 1 and 15.

1.7 The respondents brought forward further arguments based on Articles 83, 84 and 123(2) and (3) EPC against admitting the present second auxiliary request. These arguments are dealt with in paragraphs 2 to 4 below. As follows from these paragraphs, the board could not see an obstacle arising from these arguments against admitting the second auxiliary request to the present procedure.

1.8 Further, the amendments could easily be understood without causing significant delays.

1.9 Exercising its discretion pursuant to Article 13(1) RPBA, the board therefore admitted the second auxiliary request in its present form to the appeal procedure.

2. Second auxiliary request: Amendments (Articles 100(c) and 123(2) and (3) EPC)

2.1 The respondents objected to the feature "computing (420) a transformation matrix based on the best fit routine" in claim 1 of the main request as not having been originally disclosed. Since this feature is present in claim 1, point 1.5 of the second auxiliary request in a modified form, viz. "computing (420) a transformation matrix based on an output of the best fit routine", this objection is addressed in respect of this request as well.

2.2 The respondents argued that the term "best fit routine" was used in paragraph [0011] of the patent (in this respect identical to the application as filed) and in paragraph [0021] (in this respect identical to the application as filed) where it is applied to measured position data and the model. According to paragraph [0025] (in this respect identical to the application as filed) a transformation matrix is computed based on "the best fit routine". The respondents argued that the feature in question was taken literally from paragraph [0025], but without any reference to measurements and a model as in paragraph [0021]. The embodiment of paragraph [0025] therefore related to an alternative embodiment. Further, the reference in claim 1 to a "best fit" without reference to measurement data amounted to an unallowable generalisation, since a "best fit" had originally only been described with reference to measurement points.

2.3 The board does not agree. The step of computing of the matrix based on the best fit routine (point 1.5 of claim 1) refers to measurements to which a best fit routine is applied (point 1.4 of claim 1). These measurements are understood to be the result of the measuring steps in points 1.2 and 1.3 of claim 1, according to which discrete point positions and sampling surface positions are measured. This corresponds to the original disclosure in paragraph [0025] of the patent, according to which the best fit routine, on which computation of the transformation matrix is based, refers to method step 412. This step is further described in the originally disclosed paragraph [0021] of the patent, namely that the best fit is applied to measured position data which include the measured positions of the sampling surfaces and the discrete points, which the board understands to correspond to the measured discrete point and sampling surface positions.

2.4 Claim 1 of the second auxiliary request was further amended by introducing in point 1.5 the wording "an output of" before "the best fit routine".

This feature, although not literally mentioned in the original application, follows directly from it, since the computation of the transformation matrix is based on data representing the comparison between the measured position and the desired position, the comparison including applying the best fit routine (cf. paragraph [0007] and [0025] of the patent specification, these paragraphs being identical to the corresponding paragraphs in the application as filed). Hence, the wording "an output of" is originally, albeit implicitly, disclosed and, hence, does not contravene Article 123(2) EPC.

Further, the wording "an output of" narrows the scope of the claim compared to claim 1 of the patent as granted. According to the patent as granted, the computing of a transformation matrix was based on "a" best fit routine. By introducing a specific best fit routine in point 1.4 of claim 1 and referring to it in point 1.5, the scope of the feature in question in its form as granted was narrowed to this specific best fit routine. The additional wording "an output of" further narrows the scope by specifying which part of the best fit routine is used. Hence, the introduction of the wording "an output of" complies with the requirements of Article 123(3) EPC.

2.5 Further, the term "sampling surface position" in points 1.2 and 1.3 of claim 1, which replaces the term "surface position" as used in claim 1 of the patent application as originally filed and in claim 1 as granted, follows directly from paragraph [0021], first sentence, of the patent (in this respect identical to the application as filed), which refers, in relation to the measurements at blocks 404, 406 and 408 of Figure 3, to the "measured positions of the ... sampling surfaces".

2.6 The respondents further argued that the alternative "and/or" in point 1.2 of claim 1 broadened the scope of protection as compared to claim 1 of the patent (Article 123(3) EPC). The board does not agree. According to claim 1 of the patent, the measuring step (cf. point 1.2 of present claim 1) was for at least one of a first surface position and a first plurality of discrete point positions associated with the first component. Hence, claim 1 of the patent comprised a measuring step which related alternatively to a first surface position or a first plurality of discrete point positions or both. As specified in point 1.2 of present claim 1, a first plurality of discrete point positions and/or a first sampling surface position is measured. Hence, present claim 1 comprises a measuring step relating to discrete point positions or to a sampling surface position or to both. Hence, Article 123(3) EPC is complied with.

2.7 The respondents further argued that in point 1.6 of claim 1 the feature "a best fit position between the measured sampling surface position and a desired surface position is provided" relied on a best fit between two positions instead of between a shape and a position as originally disclosed (now paragraph [0011] of the patent in suit) and thus violated Article 123(2) EPC. The board does not agree and refers to paragraph [0031] (in this respect identical to the application as filed) from which it follows that at least the "as-built" component is moved to provide a best fit between the "as-built" component and the "as-designed" model. A best fit cannot actually be achieved between a "component" and a "model", but only between the corresponding measured and desired positions which, in the context of the patent, are the "measured position data", which comprise discrete point positions and the sample surface position (see paragraph [0010]) and the desired surface position. Hence, the feature in point 1.6 of claim 1 does not contravene the requirement of Article 123(2) EPC.

2.8 The board concludes that claim 1 does not infringe Article 123(2) and (3) EPC. Nor does the ground for opposition pursuant to Article 100(c) EPC prejudice the maintenance of the patent on the basis of this claim.

2.9 Analogous considerations apply to claim 15.

3. Second auxiliary request: clarity (Article 84 EPC)

3.1 The respondents argued that the term "measurements" in points 1.4 and 1.5 of claim 1 were, in comparison to claim 1 as granted, unclear due to the introduction in points 1.2 and 1.3 of the wording "measuring by scanning", since it was not clear whether the term "measurements" related to measuring by scanning in addition to the measuring of discrete point positions. This problem was further compounded by the term "measured sampling surface position" in point 1.4 of claim 1 which would leave it open whether or not it was the result of any of the previous measurement steps in points 1.2 and 1.3.

3.2 The board is of the view that these amendments in present claim 1 as compared to claim 1 as granted do not render the claim unclear. In claim 1 as granted, the term "measurement" would have been understood to relate to the measuring of discrete point positions and of surface positions. In present claim 1, the measuring of a surface position was replaced by measuring by scanning a sampling surface position. This amendment is understood as a restriction of the method used for measuring the surface position. The fact that measurements are performed on surface positions remains unchanged. Likewise, the board understands the term "measured sampling surface position" as relating to the measuring by scanning of the first (if this alternative applies, cf. feature 1.2 of claim 1) and second sampling surface position.

3.3 The respondents further argued that it was unclear whether the best fit routine in point 1.4 of claim 1 applied to the measurements, the desired position information or both. The board notes that according to claim 1 "a best fit routine [is applied] to the measurements and the desired position information". Hence, it is clearly applied to both, as also supported by paragraph [0021] of the patent.

3.4 The board is thus satisfied that the amendments to claim 1 comply with the requirements of Article 84 EPC.

3.5 Analogous considerations apply to claim 15.

4. Second auxiliary request: sufficiency of disclosure (Articles 83 and 100(b) EPC)

4.1 In this respect, the respondents referred to the feature "computing (420) a transformation matrix based on the best fit routine" in claim 1 and argued that according to steps 410 and 412 of Figure 3 of the patent first and second components are compared with a CAD-model using a best fit. According to paragraph [0021], however, the measurement data may be transformed into a coordinate system compatible with the CAD-model of the first component before the best fit routine according to step 412 is performed. Consequently, the skilled person would not know whether the best fit routine would be used for a comparison with the CAD-model as indicated in Figure 3 or that it would be applied to previously transformed data for calculation of a transformation matrix as indicated in paragraph [0025] of the patent.

4.2 It follows from column 6, lines 40 to 42, that a transformation of measurement data into the coordinate system of the CAD model may be performed. Thereafter, it is stated that a best fit routine may be applied to the measured data and the "as-designed" model, which the board understands to be the CAD model. The "best fit" routine is further described with reference to known fitting routines (column 6, lines 45 to 54). Hence, the "best fit" routine is performed after a possible transformation of the coordinate system. This is not in contradiction with Figure 3, since the statements in blocks 410 and 412 (viz. "compare (best fit) first/second component to CAD") do not mention a transformation into another coordinate system, this transformation being optional. Hence, whenever a transformation of the measurement data into another coordinate system is performed, this transformation will be performed before the the "best fit" routine is applied.

4.3 The board concludes that the amendments to claim 1 do not give rise to objections under Article 83 EPC. Nor does the opposition ground pursuant to Article 100(b) EPC prejudice the maintenance of the patent on the basis of claim 1.

4.4 Analogous considerations apply to claim 15.

5. Second auxiliary request: inventive step (Articles 52(1), 56 and 100(a) EPC)

5.1 It was common ground between the parties that D1 (US 2003/0090682 A1) represented the closest prior art.

Further, with respect to the subject-matter of claim 1 of the second auxiliary request, the respondents did not maintain their objection under Articles 52(1) and 54(1) and (2) EPC, i.e. lack of novelty.

5.2 D1 (paragraph [0001]) discloses a method of positioning one part with respect to another part which in a first embodiment is an aircraft fuselage (paragraph [0021]). The method finds application in the aircraft industry (paragraph [0002]). Hence, D1 discloses the feature in point 1.1 of claim 1.

According to the method of D1, a first and a second plurality of discrete point positions of the first part and of the second part (the fuselage), respectively, are measured, the positions being on or adjacent to the first part and second part, respectively (paragraph [0028] and Figure 1). Hence, D1 discloses the feature in point 1.2, with the exception of the specific first measurement systems, and only part of the feature in point 1.3 of claim 1. It is noted that in point 1.2 of claim 1 "measuring by scanning a first surface portion" is merely an alternative feature ("and/or").

Further, according to D1, a comparison is made between the measurements of the second part and a CAD model (paragraphs [0045] and [0046]). The CAD model is understood by the board to contain desired position information. Further, the positioning and orientation of the part can be established from the measured position of selected points which are fitted to a CAD model of the part using a "best fit" technique (paragraphs [0045] and [0046]). Hence, the comparison according to D1 is understood by the board as including applying a best fit routine. The board interprets the term "surface" in "surface fitting routine" broadly, such that a fitting routine which is used to fit the "three dimensional position of six or more non-coplanar, non-colinearly placed targets" (paragraph [0046] of D1) can be considered to be a "surface fitting routine". The board further considers that the "least mean squares" technique used to implement a "best fit" (paragraph [0046] of D1) is such that fitting criteria are weighted in such a way that certain regions of the measured positions are assigned more importance than other regions.

Further, according to paragraph [0047] of D1, the position and orientation of the fuselage section may be uniquely defined by setting three or more of the target positions on the CAD data to the measured three dimensional positions for the corresponding targets on the fuselage section. After that, the processor outputs control signals to a robot in order to re-orient and translate the first part, i.e. part 2, for eventual assembly (paragraphs [0049] to [0051]). This process requires transformation data, which is based on the previous best fit, to be transmitted to the robot. The board considers such transformation data to be, at least in a broad sense, in the form of a transformation matrix. Further, the re-orientation and translation of part 2, which is based on the previous measuring and fitting steps, leads, according to D1, to an improvement of the comparison between the measurements and the desired position information, since they determine the relationship between the CAD data of the fuselage and the measured positions.

Further, part 2 is subsequently moved according to the transformation matrix (paragraphs [0050] and [0051]).

The board notes that in D1, the measurement system maybe a photogrammetry system including two cameras (paragraphs [0025] and [0026]). Alternatively, two sets of cameras may be used, each set being used for a respective one of the parts (paragraph [0067]). Further, other measuring systems are suggested (paragraph [0069]). However, in D1, there is no disclosure of using two different measurement systems for measuring positions of one of the parts.

5.3 Hence, the subject-matter of claim 1 differs from the disclosure of D1 at least in that, in respect of the second component, measurements are made of a second sampling surface position and of a plurality of discrete point positions by using different measurement systems which are further specified in the claim (point 1.2 of claim 1).

5.4 The above distinguishing feature, which ultimately provides the "best fit" between the measured shape (which the board understands to result from the measuring by scanning of a sampling surface position) and the desired position of a component (paragraph [0011] of the patent) solves the problem of improving the assembly of large components which may deviate from their nominal design due to their complexity and non-uniform material properties (paragraph [0004] of the patent).

The method disclosed in D1, though also being concerned with the possibility of one or both parts being compliant and, hence, deviating from their nominal shape (D1, paragraph [0012], last sentence), is in such a case concerned with the position and orientation of the two parts relative to a localised area of the part to be machined or assembled; thus allowing a geometrically optimised fit with respect to the local geometries of the interface between the two parts (D1, paragraph [0012]). Hence, the teaching of D1 in a situation of compliant parts is to measure the position and orientation of the parts relative to a localised area instead of applying two different measurement methods to at least one of the parts.

5.5 Hence, even if in D1 measuring a number of targets were interpreted as measuring a sampling surface position, D1 neither discloses nor suggests the application of two different measurement methods and using the two different measurement systems to one (viz. the second) of the components. Nor is the board aware of this being part of the common general knowledge of the person skilled in the art.

5.6 For these reasons, the subject-matter of claim 1 of the second auxiliary request involves an inventive step, having regard to the disclosure of D1 and taking into account the common general knowledge (Articles 52(1) and 56 EPC).

5.7 Analogous considerations apply to system claim 15.

6. Remittal (Article 111(1) EPC)

The subject-matter of claims 1 and 15 comprises features which have not been considered by the opposition division in its decision, viz. in particular the feature in point 1.3 of claim 1 "measuring by scanning a second sampling surface position associated with the second component by using the second measurement system and measuring a second plurality of discrete point positions (116) associated with the second component (102-108) by using the first measurement system, the second plurality of discrete point positions (116) being at least one of on and adjacent to the second component" (emphasis by the board), in which these measurement systems are as defined in point 1.2 of claim 1, viz. "wherein the first measurement system includes at least one of a global positioning system, an infrared global positioning system, and a laser-based point tracking system, and the second measurement system includes at least one of a radar system, a structured light measurement system, and a scanning system". It is also noted that in the present appeal proceedings the parties exclusively considered D1 in connection with the questions of novelty and inventive step, whilst before the opposition division the opponents cited further documents D2 to D15.

The board making use of its discretion under Article 111(1) EPC thus considers it appropriate to remit the case for further prosecution, thereby giving the parties the opportunity to have their case considered by two instances.

Order

For these reasons it is decided that:

- The decision under appeal is set aside.

- The case is remitted to the department of first instance for further prosecution on the basis of claims 1 and 15 of the second auxiliary request (labelled "adapted twice") filed during the oral proceedings.