Modular construction system

Abstract

The invention relates to a modular construction system for recreational vehicles, comprising a base module and at least one additional module which can be connected thereto. The modules can be connected to one another, to a chassis, and / or to a trailer platform via standardized, releasable connecting elements to create a structure with a variable length and interior configuration. Supporting structural surfaces of the modules are at least partly in the form of multi-layer, natural-fiber-reinforced composite elements with fiber layers extending in at least three different orientations relative to each other. The matrix of the composite elements includes a thermoplastic, recyclable polymer. Deformation elements for absorbing crash energy are provided integrally in the supporting structural surfaces and / or as separate inserts or panels.

Description

Modular building block system Description

[0001] The invention relates to a modular system for recreational vehicles, comprising a base module and at least one further module connectable to it. The modules can be connected to each other, to a chassis and / or a trailer platform via standardized, detachable connecting elements, thus creating a structure with variable length and interior configuration. Load-bearing structural surfaces of the modules are at least partially designed as multi-layered, natural fiber-reinforced composite elements, the fiber layers of which run in at least three different orientations relative to each other. The matrix of the composite elements comprises a thermoplastic, recyclable polymer. Deformation elements for crash energy absorption are integrally integrated into the load-bearing structural surfaces and / or provided as separate inserts or panels.

[0002] Furthermore, the superstructure system can include at least one secondary module, in particular a rear and / or an additional module, which can be connected to the base module, the chassis, other modules or the trailer platform by means of standardized connecting elements. Background and state of the art

[0003] Recreational vehicles can generally be divided into two categories: caravans and motorhomes. Motorhomes have their own engine, while caravans do not have their own engine and are towed by an externally powered vehicle.

[0004] Both vehicle types are based on a chassis onto which the living quarters are mounted. In the case of motorhomes, the chassis can be provided either with an integrated driver's cab or without a driver's cab, in which case the driver's cab may be at least partially separate.

[0005] Currently available motorhome models cater to a wide range of user needs and are often manufactured in small numbers using a GRP sandwich construction. This means that specific models must be individually homologated, making modifications or adaptations complicated and expensive.

[0006] WO2020212455A1 discloses a modular body system for caravans, motorhomes, campervans, or recreational vehicles. The system comprises a chassis element, a roof element, and a variety of wall elements arranged between them to form exterior walls. A key feature is that at least one exterior wall is constructed from at least two vertically stacked wall elements. A disadvantage of the document is that the following features are not disclosed: • Functional interfaces with mechanically / electrically standardized connection units / interfaces (load paths, power and data connection points), designed for structure-supporting load transfer. • Defined deformation elements in module joints with calculated energy absorption for modular type approval, so that a safety-relevant, crash-homologation-capable design is lacking. • Design for ELV requirements: targeted dismantling points, sortability by type, material classification for recovery, so that the document does not address dismantling / recycling. • Modular digital IDs (QR / RFID), material-process data, life cycle and recycling paths as the basis for the digital vehicle passport, so that no life cycle / information system is designed in the document. • Multiaxial natural fiber layers with defined fiber angle orientation to combine crash performance and recyclability, so that the document remains in conventional composite without natural fiber-based, crash-optimized laminate logic. • An integration platform (security, digitalization, circular economy, modular type approval) instead of a purely constructive modular system. • Modules that are “autonomy-ready”, designed with standardized sensor-actuator interfaces, for example for radar, LiDAR and cameras, defined cable harnesses and data buses, space and mounting standards for computing and redundancy hardware, EMC and thermal management provisions. • Architectural preparation for functional safety, such as ISO 26262ZSOTIF-compliant safety reasoning at the module level, and CybersecurityZOTA update capability, such as UNECE-compliant update and security processes, and modular safety cases. • Provisions for autonomous driving functions, neither hardware-related (interface redundancy) nor procedural (security cyber verifications).

[0007] Document EP 3 636 517 B1 shows a safety cabin for motorhomes or campervans, in which at least one stabilizing deformation element is incorporated in at least one area.

[0008] One disadvantage of the safety cabin is that it is not modularly expandable, meaning that extending or replacing components is associated with considerable effort and expense. Furthermore, the safety cabin lacks a digital infrastructure that would allow for the easy integration of sensors and cameras to support driving safety.

[0009] Document US 11,794,666 B2 reveals a roof with an integrated sensor module that captures and analyzes the vehicle's environment for the implementation of autonomous driving functions.

[0010] A disadvantage of the sensor module is that it is not scalable by adding more sensors, cameras, etc.

[0011] Document DE 20 2021 105 456 U1 discloses natural fiber composite materials for load-bearing structures in caravans, wherein the fiber orientation of the natural fiber composite materials is of 0° and 90°.

[0012] However, this arrangement leads to limited strength in intermediate directions and an increased tendency of natural fibers to fray under mechanical stress. Object of the invention

[0013] Accordingly, the object of the present invention is to develop a modular system for recreational vehicles that overcomes the limitations of the known prior art. These disadvantages include, in particular, the complex and costly homologation processes for a large number of different models, the lack of modular expandability and flexibility of existing safety cabins, and the insufficient optimization of crash safety and material recycling in conventional construction methods.

[0014] Therefore, a further objective of the invention is to provide a system that enables flexible configuration and cost-effective production of recreational vehicles. This is to be achieved through the integration of deformation elements for crash energy absorption, as well as the use of fiber-reinforced composite materials to significantly improve the safety and functionality of the overall system. Summary of the invention

[0015] The problem is solved by the features of the independent claims. Advantageous embodiments of the invention are described in the dependent claims.

[0016] In a first aspect, the invention relates to a modular system for recreational vehicles, in particular for motorhomes or caravans, comprising: a base module and at least one further module attachable thereto, wherein the modules can be connected to each other and / or to a chassis or trailer platform via standardized, detachable connecting elements, so that a structure variable in its length and interior configuration is formed, wherein the load-bearing structural surfaces of the modules consist of a recyclable, fiber-reinforced composite material, and wherein the modules include integral and / or attached deformation elements for absorbing crash energy.

[0017] The modular system comprises a base module and at least one, preferably several, connectable modules, in particular intermediate modules and / or rear modules. The modules are preferably designed to be self-supporting, so that they form complete units of the living area that can be individually mounted to the chassis. This provides the modular construction capability that allows for the erection of motorhome types with different lengths and interior configurations with standardized width and height, for example preferably 1500x1500 mm to 2500x2500 mm.

[0018] A preferred feature of the invention is that these load-bearing structural surfaces of the modules are designed from a recyclable, fiber-reinforced composite material.

[0019] Furthermore, the recyclable, fiber-reinforced composite material can consist at least partially of or comprise multilayered natural fiber-reinforced composite elements, the fiber layers of which preferably have at least three different orientations relative to each other, wherein the fiber orientation is specifically adapted, for example preferably in the sequence 0°, 10°, 20°, 30°, 40° to 360° or 0°, 30°, 60°, 90° or 0°, 15°, 30°, 45°, 60°, 75°, 90°, or 0°, 5°, 10°, 15°, 20° to 360°. The layers are preferably manufactured by laying multiaxially laid UD tapes, followed by CNC placement or draping. The layers are then preferably bonded by thermoplastic consolidation in a heated mold, under pressure and temperature similar to the organosheet process. At least seven directions of bonding are required to withstand high loads.This multi-angled fiber architecture, in combination with the modular system, prevents the fraying of natural fibers under stress and surprisingly improves the energy absorption capacity of the modules in crash situations.

[0020] The cover layers are preferably made of natural fiber UD tapes and / or multiaxial fabrics (preferably flax; alternatively, for example, hemp / kenaf / jute / sisal / balsa) in a thermoplastic matrix, preferably using, for example, PP, PA, PLA, or bio-based polyesters / co-polyesters. Pre-impregnated semi-finished products such as organosheets or UD tapes are processed preferably by hot pressing, hot-press consolidation, or consolidation. Optionally, nodes and interfaces can be reinforced by overmolding or overmolding. The process windows are preferably selected material-specifically to ensure complete wetting without fiber damage. This approach offers advantages such as material recyclability, repairability and weldability, short cycle times, and a low CO2 footprint. The use of thermoplastics ensures both recyclability and efficient industrial cycle times.

[0021] Optionally, the sandwich structure can incorporate a preferred bio-based core (paper honeycomb or biopolymer foam). The layer sequences can preferably be symmetrical or gradient-patterned, for example, by locally increasing the number of layers and / or varying fiber angles. The layers are preferably bonded by thermoplastic consolidation (pressure / temperature). This allows for the creation of single-material, recyclable structures with definable stiffness and crash energy absorption without the need to define rigid process limits.

[0022] The bio-based core can preferably consist of paper or cellulose honeycomb or biopolymer foam, for example, preferably in the form of hexagonal honeycomb or closed-cell foams. The bond to the cover layer is achieved in particular by matrix flow during consolidation or by structural bonding; edge seals or crush caps are optional. Bio-based cores advantageously increase shear stiffness and energy absorption while remaining recyclable. Product purity will be a crucial aspect in the future production of caravans, especially with regard to the expected EU ELV Directive.

[0023] The basic module is a box-shaped structure, at least partially made of natural fiber composite material, and consists of at least one roof, one floor, and two opposing walls arranged parallel to the direction of travel. The two opposing walls, oriented perpendicular to the direction of travel, with the wall closer to the driver's cab being the front wall and the opposite wall being the rear wall, can be either both open, both closed, or one open and one closed. In particular, the wall and floor structure incorporates deformation elements to enhance crash safety.

[0024] In particular, the base module can preferably be rigidly coupled to the chassis using standardized connecting elements. Preferably, the base module includes a roof pod or a "sensor bar" that is integrated into the roofline of the base module. The base module can contain integrated furniture components, such as benches, a kitchenette, and / or a single seat. Additional modules, such as rear or extension modules, can be attached to the open front and / or rear walls of the base module, preferably using standardized connecting elements.

[0025] The add-on module is a box-shaped structure, at least partially made of natural fiber composite material, comprising at least one ceiling, one floor, and preferably two opposing walls, arranged primarily parallel to the direction of travel. The two opposite sides of the box-shaped structure, arranged perpendicular to the direction of travel, with the side facing the driver's cab defined as the front and the opposite side as the rear, do not have deformation walls and are therefore open in design. In particular, the wall and floor structures are designed to include deformation elements that enhance crash safety.

[0026] In particular, the add-on module can preferably be attached to the chassis using standardized connecting elements. Furthermore, the front and / or rear of the add-on module can be attached to a base module or rear module, preferably using standardized connecting elements.

[0027] The length of the add-on module can preferably vary between one and four meters. The add-on module is functionally designed, for example, as a technical module with energy storage, a sanitary module, an office module, a sleeping module, or a wardrobe / shower module. Furthermore, the add-on module is designed to be integrated into the digital infrastructure. The add-on module can be configured as a functional module containing specific technical or residential units, in particular energy, sanitary, office, sleeping, or technical modules. This ensures that the modular architecture remains functionally consistent regardless of the specific interior design.

[0028] The rear module is a box-shaped structure, at least partially constructed from natural fiber composite material. It consists of at least one roof, one floor, and two opposing walls arranged parallel to the direction of travel. The remaining side surfaces run perpendicular to the direction of travel, with the side facing the driver's cab being the front and the opposite side the rear. It forms a structure. One of the perpendicular sides is open, while the other is closed off by a solid wall. The wall and floor structure are equipped with deformation elements that increase passive safety and energy absorption in a rear-end collision.

[0029] The rear module can preferably be attached to the chassis and / or the trailer platform using standardized connecting elements. The front or rear can be attached to a base module or add-on module using the same connecting elements. Alternatively, two rear modules can be coupled together via their open front or rear sections, with at least one add-on module positioned between them, which is connected to one of the rear modules via its open sides. The resulting assembly can then be attached directly to the chassis.

[0030] The length of the rear module is flexible and can preferably vary between one and four meters. The rear modules can be designed as functional modules containing specific technical or residential units, in particular energy, sanitary, office, sleeping, or technical modules. This ensures that the modular architecture remains functionally consistent regardless of the specific interior design. The module is fully integrated into the digital infrastructure of the modular system.

[0031] For connecting the modules, pin and plug systems or dovetail-type connectors are preferably used. These connections can be further secured with screw and clamping mechanisms. This configuration allows for surprisingly simple assembly, module interchangeability, a stable structure, and advantageously contributes to the overall system's crash-resistant safety.

[0032] All modules can preferably be attached to each other, as well as to the chassis and / or a trailer platform, using standardized connecting elements. Preferred designs of these connecting elements are pin and plug systems, as well as dovetail-type elements. Screw and clamping mechanisms can be used for additional securing.

[0033] The use of these connecting elements enables surprisingly simple assembly and straightforward module replacement. At the same time, the systems ensure a stable construction and contribute significantly to the crash-resistant safety of the overall structure.

[0034] The modular design can be combined in any way from selectable modules, with the standardized connecting elements ensuring both the internal coupling of the modules and the connection to the chassis or transport vehicle.

[0035] Deformation elements are preferably integrated into all modules, especially wall and floor structures. They can be integrally formed within the laminate, for example preferably through local layer thickenings, layer number or angular gradients, and / or core modulations to enable surprisingly progressive bending and shear deformation. Optionally, they can feature local composite ribs, which allow for improved energy dissipation across the surface and minimize joints. Alternatively or additionally, deformation elements can be used as preferred separate crash boxes, panels, or Inserts made of ductile materials, such as aluminum, steel, or thermoplastic polymers, may be provided. These can be bonded to the laminate using form-fitting or material-bonding methods, for example, by co-bonding, overmolding, or laminate edging. Typical installation positions are preferably sidewall hotspots, transverse walls, seat and belt path connections, as well as front and rear areas.

[0036] Separate inserts or panels can advantageously act as the first plastic deformation phase, followed by the energy absorption of the composite material. Suitable embodiments preferably include aluminum C / U profiles, ductile thermoplastic panels, or hybrid ribs made of natural fiber composite (NFC) with a ductile surface layer. The connection can be achieved, for example, via co-bonding, overmolding, and / or mechanical fastening, such as screwing or riveting with inserts. Advantageously, separate elements provide a defined plastic phase, are replaceable and repairable, and thus enable hybrid crash management with sequential energy absorption and reduced load path bypass. However, a pure NFC structure with calculated load paths may alternatively be preferred.

[0037] The materials used advantageously not only contribute to weight reduction and sustainability, but also enable the integration of additional structural functions, in particular energy absorption and vibration damping, into the respective module segments.

[0038] The deformation elements are preferably made of multiaxially oriented natural fiber composites. An inventive further development lies in an adaptive layer structure in which the fiber orientation and / or fiber density is selectively varied to achieve functionally graded energy absorption for specific crash scenarios or load paths. The natural fibers can be woven or arranged in multiple layers, with the fiber orientation varying between adjacent layers in a fine angular sequence, for example 0°, 10°, 20°, 30°, 40° to 360°, or 0°, 30°, 60°, 90°, or 0°, 15°, 30°, 45°, 60°, 75°, 90°, or 0°, 5°, 10°, 15°, 20°, 25°, 30°. Preferably, the fiber sizes of multilayer natural fibers, of fiber-reinforced composite materials, run in at least three different orientations relative to each other.Surprisingly, this gradually graduated arrangement improves energy absorption in lateral crash loads through more even load distribution and increased material resistance.

[0039] The natural fiber composites integrated into the deformation elements can consist of flax, hemp, jute, balsa, kenaf, or sisal. Advantageously, the natural fibers are woven or arranged in multiple layers with varying fiber orientations to ensure high energy absorption and structural integrity. Preferably, as many layers as possible are used to further increase energy absorption capacity.

[0040] The deformation elements preferably have a length of 1 m to 4 m and a height of 1.5 m to 2.5 m. These dimensions allow for surprisingly precise control of the energy absorption behavior, as the impact load acting on the structure is distributed evenly.

[0041] In particular, bench seats and / or individual seats in the base module are configured as crash-relevant deformation elements, preferably being made at least partially of natural fibers. Surprisingly, it has been shown that this specific design of the seat surfaces, integrated into the modular system's structure, enables a significantly efficient transfer of the impact loads into the chassis' load paths, thus increasing the crash safety of the base module.

[0042] Natural fibers are used to implement these fiber-reinforced deformation elements. Their processing and arrangement are analogous to the principles already outlined for deformation elements. The natural fibers can preferably be arranged as woven fabrics or in unidirectional layers, with a preferred, differing fiber orientation between adjacent layers. Suitable materials include flax, kenaf, hemp, jute, balsa, or sisal, each offering specific mechanical advantages such as low density, high strength, or good elongation at break. This design using natural fibers demonstrably improves energy absorption in lateral crash loads.

[0043] Alternatively or additionally, ductile materials such as aluminium, high-strength steels or polymers can also be implemented as components of these deformation elements in the seat or furniture elements, which also exhibit improved energy absorption in the event of a lateral crash load.

[0044] In a further preferred embodiment, the recyclable, fiber-reinforced composite materials comprise that they are at least partially formed from multilayered natural fibers, the fiber layers of which run in at least three different orientations relative to each other.

[0045] This multi-angled and multi-layered fiber architecture of the natural fibers particularly prevents the fraying of the natural fibers under stress and at the same time surprisingly improves the energy absorption capacity of the modules under crash loads.

[0046] In another preferred embodiment, the natural fibers comprise flax, hemp, jute, cellulose or wood fibers.

[0047] Flax has the advantage of low density, which allows for lighter components and therefore lighter deformation elements. This reduced mass facilitates module assembly and contributes to improved fuel efficiency of the entire caravan body.

[0048] Advantageously, hemp is characterized by high strength, which means that the deformation elements offer increased protection in vehicle collisions.

[0049] Advantageously, the processing of jute requires little energy, which makes the production of the deformation elements more environmentally friendly.

[0050] Advantageously, balsa wood exhibits high stiffness combined with low weight. This allows for more collision-resistant deformation elements. design, while at the same time making the assembly and disassembly of the individual modules easier.

[0051] Advantageously, sisal has a high elongation at break, which allows the deformation elements to absorb a greater amount of energy before failure occurs.

[0052] In combination with the described angular sequence and layer architecture, this results in significantly improved, direction-dependent energy absorption, especially under lateral crash loads. This allows for a surprisingly substantial increase in the passive safety of the entire structure without compromising modularity or ease of assembly.

[0053] In the prior art, natural fiber composites for load-bearing structures are designed with fiber orientations of 0° and 90°. However, this arrangement leads to limited strength in intermediate directions and an increased tendency of the natural fibers to fray under mechanical stress. The present invention overcomes this limitation by using natural fiber composites in the load-bearing structural components of the modules, the fiber layers of which are arranged in at least three different orientations relative to each other, preferably in sequences such as 0°, 30°, 60°, 90° or 0°, 15°, 30°, 45°, 60°, 75°, 90°. This multi-angled fiber architecture results in a quasi-isotropic load distribution and enables a surprisingly significant improvement in energy absorption during crash loads.It simultaneously results in a surprisingly increased bending and torsional stiffness of the modules according to the invention, as well as targeted control of the deformation under crash load.

[0054] Preferably, the design of the fiber architecture corresponds to that described in an earlier structure by the applicant (DE 20 2021 105 456 U 1), the fiber architecture disclosed in this document being incorporated into the application by reference. This fiber architecture, in combination with the technical features of the independent claims and preferably in combination with the preferred embodiments of the invention, leads to a particularly good solution to the problem according to the invention. Therefore, the design of the fiber architecture preferably corresponds to the structure described in DE 20 2021 105 456 U 1, the disclosure of which is hereby incorporated. Thus, in one aspect, the invention does not relate to the fiber orientation itself, but rather to the novel combination of the multi-angled natural fiber architecture with the modular, crash-optimized design of the recreational vehicle structure.This combination creates an independent technical doctrine in which the modular design, the standardized connecting elements, the integrated deformation elements and the described natural fiber layers with at least three orientations work together functionally to significantly improve both the crash safety and the recyclability of the modules.

[0055] The present subject matter therefore does not concern fiber orientation per se, but rather the novel combination of multi-angled natural fiber architecture with the modular, crash-optimized design of the recreational vehicle structure. This combination creates an independent technical doctrine in which the modular design, the standardized Connecting elements, the integrated deformation elements and the described natural fiber layers with at least three orientations work together functionally to significantly improve both the crash safety and the recyclability of the modules.

[0056] Alternatively, ductile materials, such as aluminum, high-strength steels, or polymers, can also be fully or partially integrated into the deformation elements. Surprisingly, it has been shown that these materials enable improved energy absorption in lateral crash loads.

[0057] In another preferred embodiment, the connecting elements comprise a matrix comprising thermoplastic, recyclable polymer.

[0058] The thermoplastic, recyclable polymers preferably include, for example, PP, PA, PLA, or bio-based polyester / co-polymers. The cover layers of the fasteners preferably consist of natural fiber UD tapes and / or multiaxial fabrics (preferably flax; alternatively, e.g., hemp, kenaf, jute, sisal, or balsa) in a thermoplastic matrix of the aforementioned recyclable polymers. Pre-impregnated semi-finished products such as organosheets or UD tapes are preferably processed by hot pressing, hot-press consolidation, or consolidation. Optionally, nodes and interfaces can be reinforced by overmolding or overmolding. The process windows are preferably selected material-specifically to ensure complete wetting without fiber damage. This approach offers advantages such as material recyclability, repairability and weldability, short cycle times, and a low CO2 footprint.The use of thermoplastics ensures both recyclability and efficient industrial cycle times.

[0059] In another preferred embodiment, the attached deformation elements are integral to the load-bearing structural surfaces and / or provided as separate inserts / panels.

[0060] If the deformation elements are integrally integrated into the load-bearing structural surfaces, they exhibit progressive bending and shear deformation.

[0061] Alternatively, the deformation elements can be designed as separate inserts or panels and preferably connected to the load-bearing structural surfaces by means of co-bonding, overmolding, or mechanical fastening, such as screwing or riveting with inserts. Separate deformation elements allow for a defined plastic phase, are replaceable and repairable, and permit hybrid crash management with sequential energy absorption and reduced load path bypass.

[0062] In another preferred embodiment, the matrix of the modular system comprises PP, PA, PLA or bio-based polyester.

[0063] Advantageously, PP (polypropylene) has a low density, resulting in particularly favorable lightweight construction properties combined with high chemical resistance.

[0064] Advantageously, PA (polyamide) is characterized by high mechanical strength and temperature resistance, making it suitable for structurally stressed composites.

[0065] Advantageously, PLA (polylactide) enables a bio-based and potentially biodegradable material solution, thereby improving the environmental balance of the overall structure.

[0066] Advantageously, polyester / co-polyesters exhibit good thermal and mechanical stability with a reduced fossil content, thereby increasing sustainability while maintaining performance.

[0067] In another preferred embodiment, the modular system comprises a fiber orientation that forms a multi-angled architecture, providing quasi-isotropic stiffness and increased energy absorption.

[0068] This is achieved through defined orientation sets, preferably 0° ± 15° ± 30° ± 45° ± 60° ± 9°, and through local variations in the number of layers in the form of a gradient laminate. The target parameters preferably include isotropic membrane stiffness, increased shear stiffness, progressive energy absorption, and controlled load paths. These features allow for targeted adjustment of the crash behavior and the initiation of load paths via the laminate architecture.

[0069] In another preferred embodiment, the modular system includes zones with an increased number of layers and / or altered fiber orientation, which are provided in crash-critical areas of the structure.

[0070] Manufacturing is carried out using tailored layup, preferably through additional UD strakes or tapes, modified fiber angles, and, if necessary, local core densification. Preferred positions include edges, cutouts, interfaces to module connectors, cross wall and seat support connections, as well as roof and floor transitions. These zones specifically define the deformation and energy flow, or load paths, where the highest stresses occur in a crash.

[0071] In a further preferred embodiment, the composite elements of the modular system comprise a bio-based core selected from paper honeycomb or biopolymer foam.

[0072] The bio-based core can preferably consist of paper or cellulose honeycomb or biopolymer foam, for example in the form of hexagonal honeycomb or closed-cell foams. The bond to the cover layer is achieved primarily through matrix flow during consolidation or through structural bonding; edge seals or crush caps are optional. Bio-based cores surprisingly increase shear stiffness and energy absorption while remaining recyclable. Product purity will be a crucial aspect in the future production of caravans, particularly with regard to the anticipated EU ELV Directive.

[0073] In another preferred embodiment, the modular system comprises connecting elements including pin-Z plug systems, dovetail-like geometries and / or screw-Z clamping mechanisms.

[0074] Examples include preferably conical pins with locking mechanism, dovetail profiles with sliding or locking function, eccentric clamps, and screw nodes with metal inserts. The connecting elements are detachable via releasable locking mechanisms. Thermoplastic composites are preferred for profiles, while metal, particularly aluminum or stainless steel, is used for highly stressed joints. The operating principle allows for a releasable, tolerance-compensating coupling with load transfer in both longitudinal and transverse directions; locking sensors can be integrated as an option. This industrially proven, service-friendly, and tolerance-resistant connection technology enables easy assembly and disassembly as well as modular homologation.

[0075] In another preferred embodiment, the modular system comprises modules, each designed as a self-supporting unit and individually homologable.

[0076] Self-supporting means that the module bears its structural and crash-relevant loads without an additional frame. This preferably includes the load-bearing outer shell, floor, and roof with deformation zones, as well as standardized and defined interfaces to the chassis, forming a closed structure. In contrast to the interior fittings, this is a load-bearing, verifiable structure. The modules meet surprisingly relevant structural safety requirements independently of the chassis, which enables modular homologation—the core of the modular system logic.

[0077] The individual modules can be homologated by testing organizations such as TÜV, DEKRA, or GTÜ. This allows a manufacturer or customer to advantageously mount the modules in any combination on a chassis without having to subject the fully assembled caravan to further homologation. This results in a significant reduction in time and costs for both the manufacturer and the customer.

[0078] Furthermore, the self-supporting design surprisingly facilitates the single-material recycling of the modules. Once the individual modules have reached the end of their useful life, they can be detached from the structure and disassembled into their basic components. This improves the recyclability of the materials and significantly reduces disposal costs.

[0079] In another preferred embodiment, the modular system comprises deformation elements that form integral zones of the composite structure and differ from adjacent areas by a graduated number of layers and / or differing fiber angles.

[0080] The deformation elements are preferably integrally formed within the laminate, for example, by locally varying the number of layers, the fiber angles, and / or the core. The transitions occur continuously as gradients without sharp steps. This integral design avoids component separation points and improves energy transfer.

[0081] In another preferred embodiment, the modular system comprises that the deformation elements additionally have separate profiles and / or panels and / or include ductile materials such as aluminium, high-strength steels or polymers.

[0082] The profiles / panels can, for example, preferably include aluminum C / U profiles, ductile thermoplastic panels, and / or hybrid ribs (NFC plus ductile facing). The profiles / panels They are preferably joined via co-bonding, overmolding, and / or screwing / riveting with inserts. Advantageously, separate elements provide a defined plastic phase and remain interchangeable and repairable.

[0083] Preferred ductile materials, such as aluminum, high-strength steels, and polymers, preferably exhibit high ductility and energy absorption, low weight, low corrosion susceptibility, and low cost. They can preferably be joined by structural bonding, mechanical inserts, overmolding, or laminate-side tabs. Surprisingly, these ductile materials enable a reliable force-fit connection and a coordinated deformation sequence within the framework of hybrid crash management.

[0084] In another preferred embodiment, the modular system comprises a digital infrastructure including power and data bus (12 / 24 V; CAN / CAN-FD; Automotive Ethernet; LIN; spare lines), standardized connectors (M 12, FAKRA, HSD, H-MTD) and sensors (camera, radar, LiDAR, ultrasound, GNSS / IMU, environmental sensors) which can be integrated into a roof pod / sensor bar and / or decentrally via sub-controllers.

[0085] Preferably, all modules are equipped with a digital infrastructure. This infrastructure is monitored and controlled by a central control unit (ECU) and serves both sensor data fusion and the support of driving-related functions. A central power and data line extends from the control unit, routed in protected channels and connected to the module interfaces in all modules via standardized connectors, preferably taking EMC and sealing concepts into account. This embodiment advantageously features a standardized and scalable network without being tied to a specific bus. This line is designed for the transmission of supply voltage (12 / 24 V) and data lines. This automatically integrates each module connection into the network, which includes both the roof pod and externally mounted sensors.

[0086] The data line can include, for example, CAN, Ethernet, LIN, and / or FlexRay. Data communication can preferably be based on existing or future communication protocols, in particular CAN, CAN-FD, Automotive Ethernet, LIN / FlexRay, TSN, wireless module communication, or comparable communication protocols.

[0087] The central control unit can be flexibly positioned; it can be integrated either into the chassis or the body, provided its functional connection to the modular infrastructure is ensured. An innovative advancement lies in the intelligent, dynamic resource management of the control unit, which enables adaptive allocation of computing power and bandwidth for sensor data fusion and driving functions across the entire modular structure, depending on current needs and module configuration.

[0088] The roof pod is preferably a compact, aerodynamic, and encapsulated sensor housing, preferably equipped with a seal and vibration isolation. It is integrated into the roofline of the base module and preferably mechanically connected to both the base module and the digital infrastructure, with defined Interface nodes and electrical connections to the bus and power supply are utilized. A service access point to the roof pod is also preferably provided. The roof pod preferably includes a power bus system for a 12 / 24 V vehicle electrical system, a communication bus consisting of, for example, CAN, CAN-FD, Automotive Ethernet, FlexRay, LIN, or comparable systems, and a spare line. Various sensor types can be connected to the communication and power buses via standardized connectors, such as preferably M12, FAKRA, HSD, and Rosenberger HFM / H-MTD, to enhance driving safety. This configuration significantly simplifies the integration of heterogeneous sensor systems, substantially increases driving safety, and neatly integrates the sensors into the modular system without compromising the crash structure.

[0089] The types of sensors that can be used in accordance with the invention are, in particular: • Cameras • Radar sensors • LiDAR sensors • GNSS and / or GPS antenna • Inertial Measurement Units (IMUs) • Ultrasonic sensors and / or • Environmental sensors

[0090] The types of standardized connectors that can be used in accordance with the invention are, in particular: • M12 • FAKRA • HSD • Rosenberger HFM / H-MTD • MicroQuadlock System • AMP Superseal / DT German • LEMO / Binder round connectors • Coaxial connectors (SMA, SMB) • USB-C / Automotive USB Thus, the roof pod is designed in such a way that additional or improved sensors can be integrated by removing sensors that are no longer needed via plug connections and replacing them with new or expanded sensors.

[0091] Sensors can also be mounted outside the roof pod. Examples include radar sensors in the front bumper, ultrasonic sensors in the side panels, or interior cameras. External mounting advantageously allows for enhanced environmental perception, thus significantly improving driving safety. The external sensors are integrated into the digital infrastructure via local connection boxes, particularly sub-controllers.

[0092] The local connection boxes or sub-controllers are connected to the digital infrastructure, primarily via standardized ports such as Ethernet, CAN, LIN, or comparable interfaces. The sub-controllers preferably operate at 12 / 24 V and are protected against moisture and electromagnetic interference (EMI). They can preferably be attached to predefined module interfaces or flexibly positioned using magnetic or clip mounts. This allows for surprisingly flexible customization of the sub-controllers, and consequently the connected sensors, enabling local control and sensor fusion at the module level without compromising the integrity of the crash structure. Furthermore, the sub-controllers feature a surprisingly decentralized architecture, shorter cable runs, and increased robustness and scalability.

[0093] The digital infrastructure preferably comprises standardized interfaces to the chassis of the base vehicle. These interfaces serve both to supply power to the modules and to facilitate data communication with the chassis's control units. These connections allow sensor data from the modules to be integrated into the chassis, and conversely, vehicle-side data (e.g., speed, steering angle, brake pressure) to be incorporated into the control system of the modular structure. The interfaces are advantageously designed to be based on existing automotive bus systems such as CAN, CAN-FD, Automotive Ethernet, or comparable standards, with additional provision for future expansions such as TSN, FlexRay, and wireless module communication.

[0094] The connection to the chassis is made via a preferred standardized adapter unit, which is preferably attached to the module closest to the base chassis. The standardized adapter unit is standardized both mechanically and electrically. Power is preferably supplied via standardized high-current connectors. For different chassis lengths or types, the connection can be adapted using flexible cable sets or adapter plates.

[0095] The ability to integrate the various sensors into the body system, some of which are mounted in the roof pod and others at external locations on the modules, makes the body system ready for autonomous driving of levels 4 / 5.

[0096] The automation levels of autonomous driving are defined by SAE International (Society of Automotive Engineers). Level 4 and Level 5 automation levels are classified as highly automated driving. At these levels, the vehicle is capable of performing all driving functions independently without requiring human intervention, although operation is limited to predefined areas, known as control zones. Operational Design Domains (ODD) may be limited. The following paragraphs describe the possible functions as well as the preferred integration and positioning of the sensor systems used within the scope of the invention.

[0097] The LiDAR sensor can be used in particular for depth measurement, object detection and environmental scanning.

[0098] To make this function feasible, the LiDAR sensor could ideally be positioned centrally at the front of the roof module (for example, above the driver's cab) to ensure all-around visibility. Alternatively, the LiDAR sensor could be integrated into a streamlined sensor pod that is flush with the roofline. Another preferred placement option is in the corners of the roof or slightly in front of / above the A-pillars to cover blind spots. Finally, the sensor could also be mounted under the rear spoiler for reversing detection.

[0099] The radar (or millimeter wave radar) could be used preferably for detection in poor visibility conditions (such as fog or rain), for measuring distance to objects, or as a supplement to camera / LiDAR.

[0100] Furthermore, the radar could preferably be positioned under the front bumper, especially in the corners of the front flanks, in side surfaces of the base modules or rear modules (for example along the side edge at the level of the windows or the lower wall panels) or in connecting elements or connecting frames if they are structurally accessible.

[0101] The ultrasound (or proximity sensor) could be used preferably for parking assistance or in tight maneuvering areas.

[0102] The ultrasonic sensor could preferably be placed in the front and rear bumpers, on the side of the lower wall or floor threshold, or in the connecting elements between modules.

[0103] Other sensors, such as GPS, GNSS, IMU / inertial sensors, RTK, environmental sensors (such as rain, light, temperature, camera, light sensors for control, etc.) can still be used preferentially for localization, orientation, weather situation assessment, or for adaptation to environmental conditions.

[0104] The GPS or GNSS antennas are preferably arranged in an elevated, central position on the roof or rear module, so that an unobstructed line of sight to the sky is ensured and thus optimized satellite signal reception quality is guaranteed.

[0105] The IMU / inertial sensors would preferably be embedded in the rigid structure of the base module to provide a stable reference.

[0106] Ultimately, sensors for rain or light would preferably be installed on exterior surfaces, roof edges, or close to windbreaks or side windows.

[0107] The existing digital infrastructure enables the modular system to Implementation of driving functions according to autonomy levels 4 / 5. It integrates the capacity for this purpose. The system integrates various sensor components into the superstructure, with some components implemented in the roof pod and others in external module positions. The implementation of communication modules for V2X functionality and compatibility with fifth-generation (5G) and higher (6G) mobile communication standards are essential for networking the system with the external environment and ensuring safe operation in complex traffic scenarios.

[0108] An integral part of the autonomous driving architecture is the roof pod, designed to enable vehicle-to-environment communication. It serves as the technical basis for combining and connecting different types of sensors to the digital infrastructure. The sensor components are connected primarily via standardized connectors, enabling comprehensive monitoring of the vehicle's surroundings.

[0109] To further enhance environmental perception, the sensor components in the sub-controller units can also be used preferentially. The functional arrangement of these sub-controllers surprisingly serves the purpose of specialized data acquisition for autonomous driving.

[0110] The digital infrastructure also includes the standardized interface to the chassis of the base vehicle, ensuring data communication with the chassis-mounted control units for autonomous driving. This connection allows data acquired by the modular sensors to be integrated into the chassis and, conversely, vehicle-side data, such as speed, steering angle, or brake pressure, to be used to control the modular structure.

[0111] In a further preferred embodiment, the modular system comprises a structural module consisting of a self-supporting, natural fiber-reinforced composite structure with a thermoplastic matrix and at least three different fiber orientations, and featuring integral and / or separate deformation elements for absorbing crash energy.

[0112] In a further preferred embodiment, the invention comprises a method for producing a structural module comprising: a) providing and drying natural fiber layers, b) laminating / consolidating in a thermoplastic matrix under pressure / temperature, c) optionally introducing a bio-based core, d) forming multi-angled fiber architectures (> 3 orientations), e) forming integral deformation zones by layer number-orientation variation, f) joining modular connectors at defined interfaces.

[0113] The tools that are preferably used for lamination and consolidation include, for example, heated flat presses, molds, or continuous systems. The manufacturing step using the aforementioned tools enables a surprisingly improved reduction in porosity, complete wetting, and high dimensional accuracy. Time and temperature profiles are designed specifically for the material and component, with defined ramps and plateaus to protect the fibers.

[0114] The formation of integral deformation zones through variations in the number of layers and fiber orientation enables their implementation as a tailored layup, for example, through additional layers, modified fiber angles, and / or core variations. This surprisingly results in improved load path control, stiffness profiling, progressive energy absorption, and reduction of core stresses.

[0115] The modular connectors are preferably joined at defined interfaces by screws, clamps, snap-fit ​​systems, structural bonding, or thermoplastic welding in suitable materials. Tolerances are preferably defined by mating surfaces and adjustment clearances. The joining technology may preferably include overmolded inserts, overmolding, and / or co-bonding. These methods, tolerance designs, and joining technologies are surprisingly suitable for industrial applications and enable repeatable assembly as well as easy disassembly.

[0116] The defined interfaces can preferably include either mechanical coupling, such as pins, dovetails, clamps, and / or screws, and / or co-located power / data connectors. They are manufactured using laminated / overmolded inserts and mating parts and can preferably be positioned at module edges, crossbeams, and / or chassis nodes. This results in surprisingly secure and repeatable assembly, as well as reliable electrical integration.

[0117] In a further preferred embodiment, the modular system comprises that each module bears a machine-readable identification, selected from QR code, RFID tag or a comparable digital marking, for documenting material composition, manufacturing parameters and recycling path within the framework of life cycle management, wherein the identification is permanently integrated into the component or applied to its surface and is linked to a digital vehicle passport or a cloud-based data management system.

[0118] The integration of machine-readable identification into each module is a key aspect of the modular system, enabling the achievement of sustainability, cost-efficiency, and comprehensive lifecycle management. This identification, which can be implemented using QR codes, RFID tags, or similar digital markers, serves as a digital fingerprint for each module. It allows for detailed documentation and tracking throughout the entire lifecycle, from manufacturing and use to recycling. This overcomes the limitations of current technology, which does not provide for module-specific digital IDs as the basis for a digital vehicle passport.

[0119] Specifically, the documentation on these machine-readable identifiers includes a wide range of critical information. This includes the exact material composition of the modules, including specific natural fibers such as flax, hemp, jute, cellulose, or Information on wood fibers, the thermoplastic polymers used (such as PP, PA, PLA, or bio-based polyesters), and bio-based cores made of paper honeycomb or biopolymer foam is recorded. Furthermore, detailed manufacturing parameters are captured, including fiber orientation in the multilayer composite elements, thermoplastic consolidation process parameters, and the specific design of integral deformation elements through variations in layer count and fiber orientation. This data can also include information on the precise positioning of deformation elements in crash-critical areas.

[0120] This comprehensive data collection is crucial for effective lifecycle management and optimizing the recycling pathway. By clearly assigning the material composition and manufacturing processes to each module, the separation of materials by type at the end of their service life is significantly simplified and made more cost-effective, representing a substantial improvement over the current state of the art. This supports compliance with future environmental regulations, such as the ELV Directive, and promotes a circular economy by maximizing the recycling and reuse of materials. Furthermore, transparency regarding manufacturing parameters enables improved quality control and the optimization of maintenance and repair processes.

[0121] The machine-readable identification is permanently integrated into the component or applied to its surface to ensure reliable and long-lasting information availability. It is also linked to a digital vehicle passport or a higher-level, cloud-based data management system. This link enables real-time access to all relevant data, supports maintenance and repair processes by providing precise material and design information, and allows for a transparent history of the module. Integration into such a data management system complements the previously described digital infrastructure of the modular system and creates a continuous data chain that increases the efficiency, safety, and sustainability of the entire vehicle production and use process. This forms an essential basis for modular type approval and the scalability of the system. Detailed description

[0122] The invention will be explained in more detail below using examples and figures, without being limited to these. Brief description of the images

[0123] Figure 1 shows a three-dimensional representation of a structure in which a combination of a base module and a rear module is formed, wherein the base module has at least one open and one closed wall.

[0124] Figure 2 shows a three-dimensional representation of a structure in which a combination of a base module and a rear module is formed, wherein the base module has at least two open walls.

[0125] Figure 3 shows a three-dimensional representation of a structure in which a combination of a base module and a rear module is formed, wherein the base module has at least two open walls.

[0126] Figure 4 shows a three-dimensional representation of a structure in which a combination of a base module and a rear module is formed, wherein the base module has at least one open and one closed wall.

[0127] Figure 5 shows a three-dimensional representation of a structure in which a combination of a base module and a rear module is formed, wherein the base module has at least one open and one closed wall.

[0128] Figure 6 shows a three-dimensional representation of a structure in which a combination of a base module and a rear module is formed, wherein the base module has at least one open and one closed wall.

[0129] Figure 7 shows a three-dimensional representation of a structure in which a combination of a base module and a rear module is formed, wherein the base module has at least one open and one closed wall.

[0130] Figure 8 shows a three-dimensional representation of a structure in which a combination of a base module and a rear module is formed, wherein the base module has at least one open and one closed wall.

[0131] Figure 9 schematically shows a fabric made of natural fiber composites, with two fiber orientations. Detailed description of the illustration

[0132] Figure 1 shows a three-dimensional, connected representation of a structure 10, which is composed of an extended base module 1 and a rear module 2. The right side of the base module 1, arranged perpendicular to the direction of travel, has a deformation wall 4 and is thus formed as a closed side. The base module 1 also includes a horizontally arranged window n. The base module 1 and the rear module 2 are positively coupled to each other via standardized connecting elements 5.

[0133] Figure 2 shows a three-dimensional, unconnected representation of a superstructure 10, consisting of a shortened base module 1 and a rear module 2. The base module 1 and the rear module 2 can be connected to each other via standardized connecting elements 5. The right side of the base module 1, arranged perpendicular to the direction of travel, has no deformation wall 4 and is thus designed as an open side 8. A driver's cab or another module, for example a rear or additional module, can preferably be arranged or attached to the open side 8 by means of the standardized connecting elements 5.

[0134] Figure 3 shows a three-dimensional, unconnected representation of a structure 10, which consists of a central base module 1 and a rear module 2. The right side of the base module 1, arranged perpendicular to the direction of travel, has no deformation wall 4 and forms an open side 8. Furthermore, the base module 1 has a horizontally arranged window 11. A [missing information - likely a specific component] can preferably be mounted on the open side 8. The driver's cab or another module, for example a rear or additional module, can be arranged using the standardized connecting elements 5. Base module 1 and rear module 2 can be detachably connected to each other using standardized connecting elements 5.

[0135] Figure 4 shows a three-dimensional, connected representation of a structure 10, which is composed of a shorter base module 1 and a rear module 2. The right side of the base module 1, oriented perpendicular to the direction of travel, is provided with a deformation wall 4 and is thus designed as a closed side. The base module 1 and the rear module 2 are rigidly connected to each other via standardized connecting elements 5.

[0136] Figure 5 shows a three-dimensional, connected representation of a structure 10, which is composed of a central base module 1 and a rear module 2. The base module 1 and the rear module 2 are coupled to each other via standardized connecting elements 5. The right side of the base module 1, arranged perpendicular to the direction of travel, has a deformation wall 4 and thus forms a closed side. Furthermore, the base module 1 is provided with a horizontally arranged window n.

[0137] Figure 6 shows a three-dimensional, connected representation of a structure 10, formed from a shortened base module 1 and a rear module 2. The right side of the base module 1, arranged perpendicular to the direction of travel, is equipped with a deformation wall 4 and is thus formed as a closed side. The connection between the base module 1 and the rear module 2 is made via standardized connecting elements 5.

[0138] Figure 1 shows a three-dimensional, unconnected representation of a structure 10, consisting of a shorter base module 1 and a rear module 2. The right side of the base module 1, oriented perpendicular to the direction of travel, has a deformation wall 4 and is accordingly designed as a closed side. The base module 1 and the rear module 2 can be connected to each other via standardized connecting elements 5.

[0139] Figure 8 shows a three-dimensional, unconnected representation of a superstructure 10, which is composed of two rear modules 2. The right side of the left rear module 2, oriented perpendicular to the direction of travel, lacks a deformation wall 4 and is therefore designed as an open side 8. Similarly, the left side of the right rear module 2, also oriented perpendicular to the direction of travel, lacks a deformation wall 4 and is likewise designed as an open side 8. The two open sides 8 can be coupled together using the standardized connecting elements 5 to create a complete superstructure, which can then be mounted on a chassis.

[0140] Figure 9 schematically shows a fiber orientation of two fiber layers, 12 and 13, where the fibers of each layer are arranged approximately orthogonally to the next layer. Additionally or alternatively, several layered components can be used together, so that the fiber orientation changes between adjacent components. List of reference signs

[0141] 1. Basic module 2. Rear module 3. Roof 4. Deformation wall (perpendicular to the direction of travel) 5. Connecting elements 6. Floor 7. Opposite wall (parallel to the direction of travel) 8. Open side 9. Gap 10. Structure 11. Horizontal window 12. Fiber orientation 13. Fiber orientation

Claims

Patent claims 1. Modular system for recreational vehicles, comprising: a. a base module and at least one further attachable module, b. standardized, detachable connecting elements by means of which the modules can be connected to each other and / or to a chassis and / or a trailer platform, so that a structure variable in length and interior configuration is formed, c. wherein the modules comprise load-bearing structural surfaces made of a recyclable, fiber-reinforced composite material, d. and wherein the modules comprise integral and / or attached deformation elements for absorbing crash energy.

2. System according to claim 1, wherein the fiber-reinforced composite materials are at least partially formed from multilayered natural fibers, the fiber layers of which run in at least three different orientations relative to each other.

3. System according to claim 1, wherein the natural fibers comprise flax, hemp, jute, cellulose or wood fibers.

4. System according to claim 1, wherein the connecting elements comprise a matrix comprising a thermoplastic, recyclable polymer.

5. System according to claim 1, wherein the attached deformation elements are integrally integrated into the load-bearing structural surfaces and / or provided as separate inserts / panels.

6. System according to claim 4, wherein the matrix comprises PP, PA, PLA or bio-based polyester.

7. System according to one of claims 1-3, wherein the fiber orientations form a multi-angled architecture providing quasi-isotropic stiffness and increased energy absorption.

8. System according to one of claims 1-4, wherein zones with an increased number of layers and / or altered fiber orientation are provided in the crash-critical area of ​​the structure.

9. System according to any one of claims 1-5, wherein the composite elements comprise a bio-based core selected from paper honeycomb or biopolymer foam.

10. System according to any one of claims 1-6, wherein the connecting elements comprise pin / plug systems, dovetail geometries and / or screw / clamping mechanisms.

11. System according to one of claims 1-7, wherein each module is designed as a self-supporting unit that can be homologated individually.

12. System according to one of claims 1-8, wherein the deformation elements are integral zones of the composite structure which differ from adjacent areas by means of a graduated number of layers and / or differing fiber angles.

13. System according to one of claims 1-9, wherein the deformation elements additionally comprise separate profiles / panels and / or ductile materials (aluminium, high-strength steels, polymers).

14. System according to one of claims 1-10, comprising a digital infrastructure including power and data bus (12 / 24 V; CAN / CAN-FD; Automotive Ethernet; LIN; spare lines), standardized connectors (M 12, FAKRA, HSD, H-MTD) and sensors (camera, radar, LiDAR, ultrasound, GNSS / IMU, environmental sensors) that can be integrated into a roof pod / sensor bar and / or decentrally via sub-controllers.

15. Structural module for a system according to one of claims 1-11, comprising a self-supporting, natural fiber reinforced composite structure with a thermoplastic matrix and at least three different fiber orientations, as well as integral and / or separate deformation elements for crash energy absorption.

16. Method for producing a structural module according to claim 12, comprising: a. providing and drying natural fiber layers, b. laminating / consolidating in a thermoplastic matrix under pressure / temperature, c. optionally incorporating a bio-based core, d. forming multi-angled fiber architectures (> 3 orientations), e. forming integral deformation zones by varying the number of layers / orientation, f. joining modular connectors at defined interfaces.

17. System according to any one of claims 1 to 13, wherein each module bears a machine-readable identification selected from QR code, RFID tag or a comparable digital marking, for documenting material composition, manufacturing parameters and recycling path within the framework of life cycle management, wherein the identification is permanently integrated into the component or applied to its surface and is linked to a digital vehicle passport or a cloud-based data management system.

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