SYSTEM AND METHOD FOR THE DETECTION AND ACOUSTIC ANALYSIS OF FOAM INSULATION IN RAW BODY SERIES OF VEHICLES

Abstract

A system (100) for detecting and analyzing foam insulation in a building shell cavity comprises a shock generator (102), an acoustic sensor (104), and a control unit (106) connected to the shock generator (102) and the acoustic sensor (104). The control unit (106) is configured to enable the shock generator (102) to generate and apply a predefined force at a predefined location on the surface of the building shell (200) where the foam insulation (204) in the cavity (202) of the building shell (200) is to be detected and analyzed.The control unit (106) further measures acoustic attributes of acoustic signals generated when the predefined force is applied at the predefined location using the acoustic sensor (104) and analyzes the measured acoustic attributes using a learning unit to detect the presence or absence of the foam insulation (204) in the cavity (202).

Description

TECHNICAL AREA

[0001] The present invention relates generally to the field of acoustic foams in vehicle structures. In particular, the present invention relates to a system and method for detecting and analyzing the quality of foam insulation in vehicle body shells. BACKGROUND

[0002] In the automotive industry, effective sound insulation within the body-in-white (BIW) of vehicles is crucial for improving occupant comfort by reducing noise, vibration, and harshness (NVH). A widely adaptable method for achieving better sound insulation is the application of polyurethane (PU) foam to the cavities of the body-in-white. This process typically involves spraying a mixture of two chemical components, polyol and isocyanate, which react and expand to form the PU foam. The expanding foam fills the cavity and acts as sound insulation by damping vibrations and absorbing sound waves.

[0003] The success of this soundproofing technique depends heavily on the precise calculation of the cavity volume and the correct formulation of the foam to ensure that the mixture expands and completely fills the cavity without leaving any gaps or voids. This precision is crucial not only for maximizing sound insulation but also for maintaining the structural integrity and safety of the vehicle.

[0004] In modern manufacturing processes, robots are used to spray the polyol and isocyanate into the BIW cavities. These automated systems ensure a uniform application and reduce human error. However, a significant challenge arises once the foam has been applied. Because the PU foam expands in enclosed cavities, it is impossible to visually inspect the interior to determine whether the foam has adequately and evenly filled the cavity according to the calculated volume. This lack of visibility carries the risk that undetected problems, such as incomplete filling, voids, or an inappropriate foam density, will compromise sound insulation and potentially lead to NVH (noise, vibration, and harshness) issues.

[0005] In the field of filling foam into the body-in-white (BIW) structure of vehicles, some efforts have already been undertaken in the past. For example, patent DE102023001654A1 discloses a device for filling foam into a vehicle body frame, in particular the body frame, which is defined by a cavity and openings extending into the cavity. The device comprises a filling nozzle that can be connected to one of the openings formed in the body frame. The filling nozzle can be connected to a foam dispensing unit and a deformable membrane, which is connected to the filling nozzle and can be inserted into the cavity of the body frame through one of the openings.The deformable membrane is configured to expand within the cavity of the body frame and at least temporarily seal the openings defined in the body frame while the foam is being poured in. The deformable membrane facilitates the sealing of the openings in the vehicle's body frame. However, the cited reference does not offer a solution to the problem mentioned above.

[0006] Therefore, there is a need for a simple, reliable and non-invasive inspection solution to detect the foam insulation in the body-in-white of vehicles and to further check the integrity and quality of the foam insulation in the body-in-white after the foaming process, in order to ensure that the foam insulation meets the desired specifications and that the entire quality control process in the automotive industry is adhered to. OBJECTS OF INVENTION

[0007] A general object of the present invention is to ensure that the foam insulation is sufficiently, uniformly and completely introduced into the BIW cavities.

[0008] One object of the present invention is the development of a simple, reliable and non-invasive inspection solution for checking the integrity and quality of the acoustic foam insulation within the body shell of vehicles after the foaming process.

[0009] One object of the present invention is to provide a solution with which it can be confirmed that the foam application meets the exact calculations of the cavity volume and the requirements for the formulation, so that gaps, voids or an inappropriate foam density that could impair the NVH performance are avoided.

[0010] One object of the present invention is to maintain and verify the structural integrity and safety of the vehicle by ensuring that the foam has expanded correctly in the cavity without causing deformations or structural problems.

[0011] One object of the present invention is to provide a portable and non-invasive device to check the integrity and quality of the acoustic foam insulation in raw vehicle bodies after the foaming process. SUMMARY

[0012] Aspects of the present invention relate to the technical field of acoustic foam insulation in vehicle structures. In particular, the present invention relates to a system and method for detecting and analyzing the quality of acoustic foam insulation in vehicle body shells.

[0013] In one aspect, a system for detecting and analyzing foam insulation in a cavity of a body-in-white (BIW) is disclosed. The system comprises a shock-generating device, an acoustic sensor located at a predefined distance from the shock-generating device, and a control unit connected to the shock-generating device and the acoustic sensor. The control unit includes one or more processors coupled to a memory that stores instructions which can be executed by the processors. This causes the control unit to output a control signal so that the shock-generating device can generate and apply a predefined force at a predefined location on a surface of the BIW where the foam insulation in the cavity of the BIW is to be detected and analyzed.The control unit further measures acoustic attributes of acoustic signals generated when the predefined force is applied at the predefined location using the acoustic sensor, and analyzes the measured acoustic attributes using a learning unit to detect the presence or absence of foam insulation in the cavity.

[0014] The device for generating the shock can be configured to generate and apply the predefined force at the predefined location with a predefined frequency upon output of the control signal, and accordingly measure and analyze the acoustic properties of the generated acoustic signals to detect the presence or absence of the foam insulation in the cavity.

[0015] In one aspect, the control unit can be configured to detect whether the measured acoustic properties lie within a predetermined range. This range is selected based on the applied predefined force and the surface material of the BIW (Building Intermediate Water). Accordingly, in response to a positive detection, the control unit can indicate that the foam insulation should be filled into the BIW cavity at the predefined location. Conversely, in response to a negative detection, the control unit can determine that the foam insulation is not filled, or only partially filled, into the BIW cavity at the predefined location.

[0016] In one aspect, the acoustic attributes include sound intensity, with a specified range of 5 to 10 dB.

[0017] The device for generating the impact can comprise an arm movably arranged within a housing with an open end, and an actuator operationally connected to the arm and configured to move the arm between a stowed position, in which the arm remains within the housing, and an impact position, in which a predefined length of the arm protrudes from the open end of the housing. Furthermore, the actuator can be configured to move the arm into the impact position at a predefined speed upon output of the control signal in order to generate the predefined force.

[0018] Furthermore, the device for generating the impact can be configured to be positioned at the predefined location on the surface of the BIW, so that an impact end of the arm remains in the stowed position at a predefined distance from the predefined location.

[0019] Furthermore, the system can include a human-machine interface (HMI) that communicates with the control unit. The HMI can allow one or more users to set the predefined force to be applied, monitor the measured acoustic properties, and also display a result relating to the presence or absence of foam insulation in the cavity of the BIW.

[0020] In another aspect, a method for detecting and analyzing foam insulation in a cavity of a body-in-white (BIW) is disclosed. The method may include the following steps: activating a device for generating an impact by a control unit to generate and apply a predefined force at a predefined location on a surface of the body-in-white where foam insulation in the cavity of the body-in-white is to be detected and analyzed; measuring acoustic attributes of acoustic signals generated when the predefined force is applied at the predefined location by the control unit using the acoustic sensor; and analyzing the measured acoustic attributes by the control unit using a learning unit to detect the presence or absence of foam insulation in the cavity.

[0021] The procedure may include the following steps: enabling the impact to generate and apply the predefined force at the predefined location with a predefined frequency, and appropriately measuring and analyzing the acoustic properties of the generated acoustic signals to detect the presence or absence of foam insulation in the cavity.

[0022] In one aspect, the method for analyzing the measured acoustic attributes can include the steps of detecting whether the measured acoustic attributes lie within a predetermined range, where the predetermined range is selected based on the applied predefined force and the material of the BIW's surface. Accordingly, in response to a positive detection, the method can include the steps of detecting the presence or filling of the BIW's cavity at the predefined location with foam insulation. Furthermore, in response to a negative detection, the method can include the steps of detecting the absence or partial filling of the BIW's cavity with foam insulation at the predefined location.

[0023] Various objects, features, aspects and advantages of the subject matter according to the invention will become clearer from the following detailed description of preferred embodiments together with the accompanying drawing figures, in which the same numbers represent the same components. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings serve to further understand the present invention and are an integral part of this description. The drawings illustrate exemplary embodiments of the present invention and, together with the description, serve to explain the principles of the present invention. Fig. Figure 1 shows an exemplary view of the proposed system for the detection and quality analysis of acoustic foam insulation in body-in-white (BIW) vehicles according to an embodiment of the present invention. Fig. Figure 2 shows an exemplary view of the system or device for generating shocks, which is arranged on a surface of the BIW according to an embodiment of the present invention. Fig. Figure 3 shows exemplary steps of the proposed method for detecting and analyzing the quality of acoustic foam insulation in the body shells of vehicles according to an embodiment of the present invention. Fig. Figure 4A shows an exemplary view of the device for generating an impact that tests a BIW cavity filled with foam insulation, according to an embodiment of the present invention. Fig. Figure 4B shows an exemplary view of the device for generating the shock that tests an empty BIW cavity, according to an embodiment of the present invention. Fig. Figure 5 shows an exemplary architecture representing the functional modules of the system and the associated control unit according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] A detailed description of the embodiments of the invention illustrated in the accompanying drawings follows. The embodiments are described in sufficient detail to ensure the invention is clearly understandable. However, this level of detail is not intended to limit foreseeable embodiments; on the contrary, it is intended to cover all modifications, equivalents, and alternatives that fall within the spirit and scope of the present invention as defined by the accompanying claims.

[0026] The embodiments described here relate to a system and a method for detecting and analyzing the quality of acoustic foam insulation in vehicle body shells.

[0027] With reference to the Fig. 1, Fig. 2 and Fig. Section 5 discloses the proposed system 100 for detecting the presence and quality analysis of the foam insulation 204 in a cavity 202 of a body-in-white (BIW) 200. The system 100 may include a device 102 for generating an impact and an acoustic sensor 104, such as a microphone, located at a predefined distance from the device 102 for generating the impact. The device 102 for generating the impact may be configured to generate and apply a predefined force or impact. Furthermore, the acoustic sensor 104 may be configured to measure acoustic attributes, such as the intensity of acoustic signals generated when the force or impact is applied to a surface, but is not limited to this. The detailed design and operation of the device 102 for generating impacts are described in subsequent sections.

[0028] In one embodiment, the system 100 may further comprise a control unit 106, which is connected to the device 102 for generating the shock and the acoustic sensor 104. With reference to Fig. 5. The control unit 106 can comprise one or more processors 502 coupled with a memory 504 that stores instructions executable by the processors 502, which can cause the control unit 106 to perform one or more specific operations. Furthermore, the control unit 106 can be configured with a learning unit 506 that enables the control unit 106 to analyze data relating to the acoustic attributes measured by the acoustic sensor 104.

[0029] In one embodiment, the control unit 106 can be configured to output a control signal that enables the impact generation device 102 to generate and apply a predefined force or impact at a predefined location on the surface S of the BIW 200, where the foam insulation 204 in the cavity 202 of the BIW 200 is to be detected and analyzed. Furthermore, the control unit 106 can use the acoustic sensor 104 to measure acoustic attributes of acoustic signals generated when the predefined force is applied at the predefined location on the surface S of the BIW 200. Finally, the control unit 106 can use the learning unit 506 to analyze the measured acoustic attributes to detect the presence or absence of the foam insulation 204 in the cavity 202.

[0030] In another embodiment, the control unit 106 can be configured to output the control signal so that the device 102 can generate and apply a predefined force or shock at a predefined frequency or for a predefined number of times to the surface S of the BIW 200. Furthermore, the control unit 106 can use the acoustic sensor 104 to measure the acoustic attributes of the acoustic signals generated at the predefined location with each application of the predefined force or shock. Finally, the control unit 106 can use the learning unit 506 to analyze the measured acoustic attributes to detect the presence or absence of the foam insulation 204 in the cavity 202.

[0031] In one embodiment, the control unit 106 can coordinate and synchronize the operation of the shock-generating device 102 and the acoustic sensor 104 at the predefined frequency, so that the acoustic sensor 104 can effectively detect and measure the acoustic attributes of the acoustic signals generated by the shock-generating device 102 when each shock is applied to the predefined location on the surface S of the BIW 200, while simultaneously preventing the acoustic sensor 104 from detecting multiple acoustic signals during a single shock.

[0032] In one embodiment, the control unit 106 can be configured to detect whether the measured acoustic properties during the generation of the impact on the surface S of the BIW 200 lie within a predetermined range. This predetermined range can be selected based on the magnitude of the applied predefined force and the material of the surface S of the BIW 200. In a non-restrictive example, the predetermined range of acoustic intensity can be chosen between 5 and 10 dB for a hard material such as steel or iron used in the BIW 200. In general, the sound intensity emitted by an empty BIW cavity 404 (as in Fig. 4B) is generated, be louder than the sound intensity generated by a BIW cavity 404 filled with foam insulation (such as the foam insulation 204) (as shown in Fig. 4A), is generated upon impact 406. Accordingly, the control unit 106 can detect, in response to a positive detection where the measured acoustic attributes are within the predetermined range, that the foam insulation 204 in the cavity 202 of the BIW 200 is filled or present at the predefined location, as shown in Fig. 4A shown. Furthermore, the control unit 106 can detect, in response to a negative detection where the measured acoustic attributes are outside the predetermined range, that the foam insulation 204 in the cavity 202 of the BIW 200 is not filled or only partially filled at the predefined location, as shown in Fig. 4B is shown. Furthermore, the quality of the foam insulation 204 filled into the BIW cavity 202 can also be analyzed based on the analysis of the measured acoustic signals.

[0033] In one embodiment, as described in Fig. As shown in Figure 1, the device 102 for generating impacts can comprise an arm 102-2 or a longitudinal element, which is movably arranged in a housing 102-1 with an open end. The device 102 for generating impacts can further comprise an actuator 102-3, which is functionally connected to the arm 102-2 and configured to move the arm 102-2 between a stowed position 108, in which the arm 102-2 remains in the housing 102-1, and an impact position 110, in which a predefined length of the arm 102-2 extends from the open end of the housing 102-1. Furthermore, the actuator 102-3 can be configured to move the arm 102-2 at a predefined speed in the direction of the impact position 110 in order to generate the predefined force or impact that is desired.which is required to inspect the BIW cavity 202 and thereby detect the presence or absence of the foam insulation 204 in the BIW cavity 200. In this way, it can be determined whether the foam application meets the exact calculations of the cavity volume and the formulation requirements, thus eliminating gaps, voids, or an inappropriate foam density that could impair NVH performance.

[0034] In an exemplary embodiment, the actuator 102-3 may comprise a motor which can be connected to the arm 102-2 using a linear actuating mechanism selected from, but not limited to, a leadscrew, rack and pinion mechanism, cam and drive mechanism, belt and pulley mechanism and slider-crank mechanism.

[0035] As in Fig. As shown in Figure 2, the device 102 for generating the impact can be configured to be positioned at the predefined location on the surface S of the BIW 200, such that the impact end of the arm 102-2 remains at a predefined distance from the predefined location in the stowed position 108. Accordingly, upon receiving the control signal from the control unit 106, the device 102 for generating impacts can generate and apply the predefined force or impact at the predefined location, which can produce acoustic signals upon impact with the surface S of the BIW 200. Consequently, the control unit 106 can measure and analyze the acoustic attributes of the generated acoustic signals to detect the presence or absence of the foam insulation 204 in the cavity 202.

[0036] Furthermore, the system 100 can include a human-machine interface (HMI) 508 that communicates with the control unit 106. In an exemplary embodiment, the HMI device 508 can comprise any display, buttons, a touchscreen display, and status LEDs. The HMI device 508 can allow one or more users to set the predefined force or impact to be applied to the surface S of the BIW 200, to monitor the acoustic attributes measured by the acoustic sensor 104, and to display a result relating to the presence or absence of the foam insulation 204 in the cavity 202 of the BIW 200.

[0037] In one embodiment, the impact generator device 102, the acoustic sensor 104, the control unit 106 and the HMI device 508 can be enclosed in a single housing and / or configured to form a self-contained device (100A in Fig. 1) form a device capable of detecting the presence of the foam insulation 204 in the BIW cavity 202 and analyzing its quality. This independent device 100A can be configured to be positioned at the predefined location on the surface S of the BIW 200 where the foam insulation 204 in the cavity 202 of the BIW 200 is to be detected and analyzed, as shown in Fig. 2 shown, so that an impact end of the arm 102-2 protrudes from the housing and remains at a predefined distance from the predefined location in the stow position 108.

[0038] In one embodiment, the control unit 106, the shock-generating device 102, the acoustic sensor 104, and the HMI device 508 may include a transceiver or a communication module 510 to connect the control unit 106 to one or more components of the system 100 via a network using wired and / or wireless media. Furthermore, the control unit 106 may communicate via the network with a central server or computer device and the associated database to transmit data regarding the predefined force or shock set by the user or applied to the surface S of the BIW 200, the monitored acoustic attributes measured by the acoustic sensor 104, and the result regarding the presence or absence of the foam insulation 204 in the cavity 202 of the BIW 200 to the central server or computer device for recording or further analysis.

[0039] In Fig. Section 3 describes method 300 for the detection and quality analysis of acoustic foam insulation in vehicle body shells. Method 300 can include the control unit, the shock generation device, the acoustic sensor, and the HMI device connected to the system of Fig. 1 are connected.

[0040] In one embodiment, method 300 may include step 302, in which the control unit activates a shock-generating device to generate and apply a predefined force at a predefined location on a surface of the BIW where the foam insulation in the cavity of the BIW is to be detected and analyzed. Method 300 may simultaneously include step 304, in which the control unit, using the acoustic sensor, measures the acoustic properties of the acoustic signals generated when the predefined force is applied at the predefined location in step 302. Furthermore, method 300 may include step 306, in which the control unit, using a learning unit, analyzes the acoustic attributes measured in step 304 to detect the presence or absence of the foam insulation in the cavity.

[0041] In another embodiment, the method 300 in step 302 may include the steps of activating the device for generating the shock in order to generate and apply the predefined force at the predefined location with a predefined frequency, followed by steps 304 and 306 for measuring and analyzing the acoustic attributes of the generated acoustic signals in order to detect the presence or absence of the foam insulation in the cavity.

[0042] In one embodiment, method 300 in step 306 may include the steps of detecting whether the measured acoustic attributes during the generation of the impact on the BIW surface are within a predetermined range. This predetermined range may be selected based on the magnitude of the applied predefined force and the material of the BIW surface. In a non-restrictive example, the predetermined range of acoustic intensity may be chosen to be between 5 and 10 dB for a hard material such as steel or iron used in the BIW. Accordingly, in response to a positive detection where the measured acoustic attributes are within the predetermined range, method 300 may include the steps of detecting the foam insulation that is filled into or present in the cavity of the BIW at the predefined location.Furthermore, in response to a negative detection where the measured acoustic attributes are outside the predetermined range, the procedure 300 may include the steps of detecting the foam insulation as not being, or only partially being, filled in the cavity of the BIW at the predetermined location.

[0043] Thus, the present invention provides a simple, reliable and non-invasive system and device to detect the foam insulation in the body cavities of vehicles and to check the integrity and quality of the foam insulation in the body shell after the foaming process, in order to ensure that the foam insulation meets the desired specifications and that the entire quality control process in the automotive industry is fulfilled.

[0044] It is obvious to the person skilled in the art that, although various embodiments and figures of the present invention have been developed for the proposed system for the detection and quality analysis of acoustic foam insulation in vehicle body shells, the teachings of the present invention are equally applicable to the detection and quality analysis of acoustic foam insulation filled into cavities of non-vehicle structures, and that all such embodiments fall within the scope of the present invention without any limitations.

[0045] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention can be developed without deviating from the fundamental scope of the invention. The scope of the invention is defined by the following claims. The invention is not limited to the described embodiments, variants, or examples, provided that they are included to enable a person with ordinary technical knowledge to manufacture and use the invention when combined with information and knowledge available to such a person. ADVANTAGES OF THE INVENTION

[0046] The present invention ensures that the foam insulation is sufficiently, evenly and completely introduced into the BIW cavities.

[0047] The present invention offers a simple, reliable and non-invasive inspection solution for checking the integrity and quality of the acoustic foam insulation within the body shell of vehicles after the foaming process.

[0048] The present invention provides a solution for confirming that the foam application meets the exact calculations of the cavity volume and the formulation requirements, thereby avoiding gaps, voids or an inappropriate foam density that could impair NVH performance.

[0049] The present invention contributes to maintaining and verifying the structural integrity and safety of the vehicle by ensuring that the foam in the cavity expands correctly without causing deformations or structural problems.

[0050] The present invention provides a portable and non-invasive device for checking the integrity and quality of the acoustic foam insulation in raw vehicle bodies after the foaming process. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 102023001654A1

[0005]

Claims

[1] System (100) for detecting and analyzing a foam insulation (204) in a cavity (202) of a body-in-white (BIW) 200, wherein the system (100) comprises: a device (102) for generating a shock; an acoustic sensor (104) positioned at a predefined distance from the device (102) for generating the shock; and a control unit (106) connected to the device (102) for generating shocks and the acoustic sensor (104), wherein the control unit (106) comprises one or more processors (502) coupled to a memory (504) which stores instructions that can be executed by the processors (502), causing the control unit (106) to: to output a control signal to enable the device (102) to generate the shock, to generate and apply a predefined force at a predefined location on a surface of the BIW (200) where the foam insulation (204) in the cavity (202) of the BIW (200) is to be detected and analyzed; using the acoustic sensor (104) to measure acoustic attributes of acoustic signals generated when the predefined force is applied at the predefined location; and to analyze the measured acoustic properties using a learning unit in order to detect the presence or absence of the foam insulation (204) in the cavity (202). [2] System (100) according to claim 1, wherein the device (102) for generating the shock is configured such that, upon output of the control signal, it generates and applies the predefined force at the predefined location with a predefined frequency and accordingly measures and analyzes the acoustic attributes of the generated acoustic signals in order to detect the presence or absence of the foam insulation (204) in the cavity (202). [3] System (100) according to claim 1, wherein the control unit (106) is configured such that it: detects whether the measured acoustic attributes are within a predetermined range, the predetermined range being selected based on the applied predefined force and the material of the surface of the BIW (200); In response to a positive detection, the foam insulation (204) is detected, which is to be filled into the cavity (202) of the BIW (200) at the predefined location; and In response to a negative detection, it was detected that the foam insulation (204) in the cavity (202) of the BIW (200) is not filled or only partially filled at the predefined location. [4] System (100) according to claim 3, wherein the acoustic attributes include the sound intensity and wherein the predetermined range is 5 to 10 dB. [5] System (100) according to claim 1, wherein the device (102) for generating shocks comprises: an arm (102-2) which is movably arranged in a housing (102-1) with an open end; and an actuator (102-3) that is functionally connected to the arm (102-2) and configured to move the arm (102-2) between a stowed position (108) in which the arm (102-2) remains inside the housing (102-1) and an impact position (110) in which a predefined length of the arm (102-2) protrudes from the open end of the housing (102-1), wherein the actuator (102-3) is configured upon output of the control signal to move the arm (102-2) to the impact position (110) at a predefined speed in order to generate the predefined force. [6] System (100) according to claim 5, wherein the device (102) for generating the impact is configured to be positioned at the predefined location on the surface of the BIW (200) such that an impact end of the arm (102-2) remains at a predefined distance from the predefined location in the stowed position (108). [7] System (100) according to claim 1, wherein the system (100) comprises a human-machine interface (HMI interface) in communication with the control unit (106), wherein the HMI interface enables one or more users to set the predefined force to be applied, to monitor the measured acoustic attributes and to display a result relating to the presence or absence of the foam insulation (204) in the cavity (202) of the BIW (200). [8] Method (300) for detecting and analyzing a foam insulation (204) in a cavity (202) of a body-in-white (BIW (200)), wherein the method (300) comprises the following steps: Enabling (302) a control unit (106) to generate and apply a predefined force at a predefined location on a surface of the BIW (200) by means of a shock generation device (102), where foam insulation (204) in the cavity (202) of the BIW (200) is to be detected and analyzed; Measuring (304), by the control unit (106), using the acoustic sensor (104), acoustic attributes of acoustic signals generated when the predefined force is applied at the predefined location; and Analyzing (306) the measured acoustic attributes by the control unit (106) using a learning unit to detect the presence or absence of the foam insulation (204) in the cavity (202). [9] Method (300) according to claim 8, wherein the method (300) comprises the steps of enabling the impact to generate and apply the predefined force at the predefined location with a predefined frequency, and accordingly measuring and analyzing the acoustic attributes of the generated acoustic signals to detect the presence or absence of the foam insulation (204) in the cavity (202). [10] Method (300) according to claim 8, wherein the method (300) for analyzing the measured acoustic attributes comprises the following steps: Detect whether the measured acoustic attributes are within a predetermined range, wherein the predetermined range is selected based on the applied predefined force and the material of the surface of the BIW (200); as a response to a positive detection, detecting the foam insulation (204) that is filled into or present in the cavity (202) of the BIW (200) at the predefined location; and as a reaction to a negative detection, the detection that the foam insulation (204) in the cavity (202) of the BIW (200) is not or only partially filled at the predefined location.

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