A template-free construction and operation method and system for a prefabricated building free-form curved enclosure structure

Abstract

The present application provides a template-free construction and operation method and system for the free-form surface enclosure structure of fabricated buildings. The method can form a continuous thin enclosure structure by spraying polymer modified fiber reinforced composite slurry on the outside of the enclosure structure base structure using unmanned aerial vehicles based on the free-form surface morphology of fabricated buildings to complete the forming of the free-form surface enclosure structure of fabricated buildings. During the operation of the building, the unmanned aerial vehicle is used to non-contact scanning detection of the outer surface of the enclosure structure, and the cracks, thinning or insufficient thickness areas are identified according to the scanning results, and the corresponding areas are implemented directional spraying by the unmanned aerial vehicle to realize the repair and thickness supplement of the enclosure structure. The present application constructs a closed-loop technical scheme integrating assembly forming, state detection and maintenance and repair, reduces the dependence on the overall template and manual high-altitude operation, and improves the safety, efficiency and maintainability of the construction and operation of the free-form surface enclosure structure of fabricated buildings.

Description

Technical Field

[0001] This invention relates to the field of robot construction technology for free-form ice shells of prefabricated buildings, and in particular to a template-free construction and operation and maintenance method and system for free-form ice shell structures of prefabricated buildings. Background Technology

[0002] Prefabricated free-form building envelopes are a type of spatial thin-shell structure using polymer-modified fiber-reinforced ice composite materials as the main shelling material. They are commonly used in ice and snow architecture, public activity spaces, and ice and snow landscape facilities in cold regions. This type of material is prepared using water as a base and fibers as an additive, with polymer components used to improve the performance of the slurry spraying application and the overall integrity after freezing. These structures typically feature complex curved surfaces, high requirements for overall continuity, and low construction temperatures, placing high demands on construction methods, safety, and construction organization during their construction and maintenance.

[0003] Existing construction methods for this type of structure largely rely on on-site casting to create formwork or molds, followed by manual segmented construction and handheld spraying equipment to define the structural form. In actual engineering projects, this method generally suffers from problems such as uncontrollable precision, high costs for formwork fabrication and dismantling, long construction periods, and significant material waste. Furthermore, in cases of complex curved surfaces or large spans, ensuring forming accuracy and structural continuity is difficult, heavily reliant on the experience and skill level of the workers. Simultaneously, the construction process typically requires manual labor in high-altitude, low-temperature, and slippery environments, posing significant safety risks.

[0004] After the free-form ice shell structure of prefabricated buildings is put into use, the outer surface of the ice shell is prone to damage such as local melting, thinning, or cracking due to factors such as changes in ambient temperature, wind load, sunlight, and usage. Existing maintenance methods mostly rely on manual inspection and local repairs, which have low detection efficiency and make it difficult to detect hidden defects in a timely manner. When the structure is large in scale or the surface is complex, the maintenance difficulty increases further.

[0005] In addition, some prefabricated buildings use a one-time molding method for their free-form ice shell structure. Once the molding is completed, it is difficult to repair or supplement the thickness locally. Once local damage occurs, it often requires large-scale respraying or even complete reconstruction, resulting in high maintenance costs and resource consumption.

[0006] With the development of prefabricated building technology, using prefabricated components for on-site assembly to improve construction efficiency and safety has become an important direction in the field of building engineering. However, the application of existing prefabricated technology in ice shell structures is still relatively limited, and there is a lack of a systematic technical solution that can achieve formwork-free molding of ice shells under the premise that the overall shape and component shape are determined, while also taking into account the inspection and maintenance during operation.

[0007] Therefore, how to complete the on-site construction of free-form ice shell structures based on prefabricated components without relying on integral prefabricated templates, and how to achieve efficient, safe, and repeatable inspection and maintenance during the operation of the ice shell, remains a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0008] The purpose of this invention is to solve the problems in the prior art and to propose a template-free construction and operation and maintenance method and system for prefabricated building free-form surface enclosure structures.

[0009] This invention is achieved through the following technical solution: This invention proposes a formworkless construction and operation method for prefabricated building free-form surface enclosure structures, the method comprising the following steps: S1, Construction preparation, site leveling and positioning With the overall spatial form, component types, and individual component shapes of the prefabricated building's free-form surface enclosure structure already determined, the construction site is cleaned, leveled, and its foundation is positioned. An unmanned aerial vehicle (UAV) is used to perform non-contact scanning of the construction site, acquiring surface elevation and flatness information. Based on the scanning feedback, the grounding area of ​​the enclosure structure and the working area of ​​the robotic arm are leveled to ensure the grounding area meets preset flatness and uniform elevation requirements. On this basis, installation baselines and elevations for rigid components, as well as assembly positioning baselines for EPS components, are established. S2, rigid components and EPS components are assembled to form a free-form surface base structure. According to the predetermined spatial location and assembly sequence, the rigid components are first installed at the corresponding positioning reference to form the boundary constraint of the free-form surface enclosure structure; then, the robotic arm is used to grab, transport and position the EPS components, so that each EPS component is connected to the rigid component and adjacent EPS components in sequence, gradually forming the base structure of the continuous free-form surface enclosure structure. The installation position, splicing relationship and node connection status of the EPS components are all controlled by the preset positioning reference. S3, Assembly result verification and base structure inspection After the base structure of the enclosure structure is assembled, it is subjected to assembly verification and construction inspection. The verification and inspection include at least: spatial position verification of rigid components, splicing continuity inspection of EPS components, node connection status inspection, surface continuity inspection of the base structure of the enclosure structure, and overall stability inspection. When the verification results meet the preset requirements, the material preparation and spraying molding stage begins. S4, Slurry Formulation of Polymer-Modified Fiber-Reinforced Composite Ice Water, fiber components, and polymer components are metered, mixed, and stirred according to a preset formula to prepare a polymer-modified fiber-reinforced ice composite slurry suitable for spraying on unmanned aerial vehicles. The fiber components are used to improve the crack resistance and toughness of the composite ice material after freezing, and the polymer components are used to improve the adhesion, spraying layering performance, and overall integrity of the slurry after freezing. S5, Unmanned Aerial Vehicle, Template-Free Spray Coating and Freezing Shell Formation Without setting an integral molding template, an unmanned aerial vehicle is used to perform a spraying operation along the outer surface of the base structure of the enclosure structure, spraying the polymer-modified fiber-reinforced composite ice slurry onto the outer surface of the enclosure structure; the slurry freezes layer by layer and is continuously stacked in a low-temperature environment to form a finish covering the outside of the free-form enclosure structure; when the thickness of the finish reaches the preset design range, the templateless molding of the prefabricated building free-form enclosure structure is completed; the base structure of the enclosure structure is a permanent supporting component after molding and is not an integral molding template to be removed after construction; S6, Non-contact scanning monitoring After the freeform surface enclosure structure is formed and during operation, an unmanned aerial vehicle is used to perform non-contact scanning monitoring on the outer surface of the cladding to obtain geometric morphology information, surface temperature information and / or thickness status information of the outer surface of the cladding, so as to characterize the operating status of the cladding. S7, Defect Identification and Repair Area Determination Based on the scanning and monitoring results, the condition of the outer surface of the finish is analyzed to identify cracks, thinning, local insufficient thickness or abnormal surface continuity areas, and the abnormal areas are determined as areas to be repaired or areas to be thickened according to preset judgment conditions. S8, directional touch-up repair and thickness compensation The unmanned aerial vehicle is controlled to perform directional spraying on the area to be repaired or the area to be thickened, and the polymer modified fiber reinforced composite ice slurry is sprayed onto the corresponding target area and then re-frozen and molded in a low temperature environment to achieve crack filling, restoration of surface continuity and local thickness compensation. S9, Repair Result Re-inspection and Cyclic Maintenance After the targeted spraying is completed, an unmanned aerial vehicle is used to conduct non-contact scanning and monitoring of the repaired area and to re-inspect the repair results. During the operation of the enclosure structure, the steps of scanning and monitoring, defect identification, targeted spraying and re-inspection are repeated to form a cyclical maintenance mechanism for the free-form surface enclosure structure.

[0010] Furthermore, in step S1, the robot arm base layout area, track installation center line, and rigid component installation positioning reference are further determined. The robot arm base layout area is determined jointly based on the planar projection boundary of the freeform surface enclosure structure, the assembly sequence of EPS components, and the reachable workspace of the robot arm, so that the robot arm can continuously cover the target assembly area and have overlapping working ranges between adjacent layout stations, thereby reducing repeated displacement and assembly interruptions of the robot arm during construction.

[0011] Furthermore, in step S2, the EPS components are installed sequentially according to a predetermined assembly sequence, which is determined based on the spatial position of the EPS components in the enclosure structure, their splicing relationship, construction stability requirements, and their connection relationship with rigid components.

[0012] Furthermore, in step S3, the construction inspection is carried out using a collaborative operation mode of unmanned aerial vehicles. The unmanned aerial vehicle performs non-contact cruise scanning on the assembled enclosure structure base structure to obtain the spatial position, surface morphology and splicing status information of rigid components, EPS components and node areas, and identifies and provides feedback on assembly deviations, surface discontinuities and local installation anomalies based on the scanning results.

[0013] Further, in step S4, the proportion of the polymer-modified fiber-reinforced composite slurry is calculated using the mass fraction method, assuming the total mass of the slurry is... The mass of the fiber component is The polymer component mass is The mass of water is Then the following conditions are met: The relationship between the total mass and the masses of each component satisfies:

[0014] The mass percentage of fiber components is The mass percentage of polymer components is The mass percentage of water is And satisfy Based on the preset total amount of ingredients and the mass fraction of each component, the actual mass of each component is calculated.

[0015] Furthermore, the formulation of the polymer-modified fiber-reinforced composite ice slurry is determined based on the following factors: ambient temperature during construction, spraying method using unmanned aerial vehicles, slurry spray flowability requirements, spray adhesion performance requirements, interlayer freezing time requirements, crack resistance requirements after freezing and molding, and overall finish requirements. Specifically, when it is necessary to improve the crack resistance and toughness of the slurry after freezing and molding, the fiber component ratio is increased; when it is necessary to improve the adhesion of the slurry to the substrate surface and the stability of the spray layer, the polymer component ratio is increased; when it is necessary to ensure the slurry's pumping performance, atomization performance, and spray uniformity, the water ratio is adjusted.

[0016] Furthermore, in step S6, an unmanned aerial vehicle equipped with a non-contact scanning module is used to perform body-to-body scanning along a preset cruising path on the outer surface of the freeform surface. Under the condition of maintaining a preset working distance and scanning attitude, geometric contour data, surface temperature data and surface image data of the outer surface of the surface are collected, and the collected data are converted into geometric morphology information, surface temperature information and / or thickness status information that characterize the operating state of the surface.

[0017] Further, in step S7, based on the point cloud data, appearance image data, and temperature field data acquired and registered by the unmanned aerial vehicle, anomaly identification and state determination are performed on the freeform surface finish outer surface; by comparing the measured geometric contour with the design model, the base structure benchmark model, and / or the historical scan model, cracks, thinning, local insufficient thickness, or abnormal surface continuity areas on the finish outer surface are identified, and the spatial location, influence range, and defect type of the abnormal area are determined according to preset judgment conditions, and it is divided into areas to be repaired or areas to be thickened, and target area information is generated to guide the subsequent unmanned aerial vehicle to carry out directional spraying repair and thickness compensation.

[0018] Furthermore, in step S8, based on the target area information generated in step S7, the unmanned aerial vehicle is controlled to perform directional spraying on the area to be repaired or the area to be thickened, and the polymer-modified fiber-reinforced composite ice slurry is sprayed onto the corresponding target area; the unmanned aerial vehicle controls the spraying path, spraying range and spraying amount according to the spatial location, boundary range, defect type and thickness compensation requirements of the target area, and makes the slurry refreeze and solidify in a low temperature environment to achieve crack filling, restoration of surface continuity and local thickness compensation.

[0019] This invention also proposes a formworkless construction and operation system for prefabricated building free-form surface enclosure structures, the system comprising: The site scanning and benchmark establishment module is used to perform non-contact scanning of the construction site before construction, obtain elevation and flatness information of the construction site surface, and establish a unified elevation benchmark for the grounding area of ​​the freeform surface structure, the installation benchmark line of the ring beam component, the installation elevation, and the assembly positioning benchmark of the EPS component. The robotic arm layout and track support module is used to determine the robotic arm base layout area and track installation centerline based on the planar projection boundary of the freeform surface enclosure structure, the component assembly sequence, and the reachable workspace of the robotic arm, and to form a track support system suitable for the robotic arm to run along the periphery of the freeform surface; The low-temperature operation protection module is used to implement zoned preheating, start-stop thermal stability control and position compensation control for the robot arm base, joint drive unit and end effector in extremely cold environments, so as to ensure the assembly accuracy of the robot arm under low-temperature start-stop conditions. The rigid component and EPS component assembly module is used to install the ring beam rigid component according to the installation datum line, installation elevation and assembly positioning datum, and to use a robotic arm to grab, transport and position the EPS component to form a free-form surface base structure. The assembly verification and construction inspection module is used to perform spatial position verification, splicing continuity inspection, node connection status inspection, surface continuity inspection, and overall stability inspection on the assembled freeform surface base structure. The composite slurry preparation module is used to meter, mix, and stir water, fiber components, and polymer components according to a preset ratio to prepare a polymer-modified fiber-reinforced composite ice slurry suitable for spraying on unmanned aerial vehicles. The unmanned aerial vehicle (UAV) spray coating shell module is used to control the UAV to perform spray coating operations along the outer surface of the EPS substrate structure without setting an overall molding template, so that the polymer modified fiber reinforced composite ice paste is frozen layer by layer in a low temperature environment and continuously stacked to form a free-form composite ice finish. The non-contact scanning monitoring module is used to control an unmanned aerial vehicle to carry a scanning device to perform non-contact scanning on the outer surface of the cladding after the enclosure structure is formed and during operation, so as to obtain geometric morphology information, surface temperature information and / or thickness status information of the outer surface of the cladding. The defect identification and area determination module is used to identify cracks, thinning, local insufficient thickness or abnormal surface continuity areas on the outer surface of the finish based on the scanning monitoring results, and determine them as areas to be repaired or areas to be thickened. The directional spraying repair module is used to control the unmanned aerial vehicle to perform directional spraying on the target area according to the spatial location, boundary range and defect type of the area to be repaired or thickened, so as to refreeze and mold the polymer modified fiber reinforced composite ice slurry to achieve crack filling, restoration of surface continuity and local thickness compensation. The re-inspection and cyclic maintenance module is used to perform non-contact scanning and monitoring of the repaired area again after the directional spraying is completed, and to repeat the scanning and monitoring, defect identification, directional spraying and re-inspection steps during the operation of the enclosure structure; The collaborative control module is connected to each of the above modules to establish a unified coordinate benchmark, a unified data interface, and a unified task scheduling relationship. It controls the collaborative operation of each module in the order of "site scanning and benchmark establishment - robotic arm assembly into base - assembly verification - UAV spraying into shell - scanning monitoring - defect identification - directional touch spraying - re-inspection and maintenance", thereby forming a template-free construction and operation and maintenance closed-loop system for prefabricated building free-form surface enclosure structures.

[0020] The beneficial effects of this invention are: 1) Achieve formwork construction of free-form building envelope structures without formwork. This invention uses rigid components such as ring beams and EPS components to assemble a free-form surface base structure. Then, an unmanned aerial vehicle is used to spray polymer-modified fiber-reinforced composite ice slurry on the outside of the base structure. The slurry freezes layer by layer in a low-temperature environment to form a free-form surface composite ice finish. The free-form surface enclosure structure is formed without the need for an integral molding template, avoiding the problems of complex manufacturing, difficult dismantling, high cost and material waste caused by traditional integral template construction.

[0021] 2) Improve the construction accuracy and shape controllability of complex free-form surface enclosure structures. Before construction, this invention uses unmanned aerial vehicles (UAVs) to acquire site elevation and flatness information and establish a unified installation benchmark. During the assembly stage, a robotic arm combined with vision, laser ranging, and inertial measurement information is used to achieve high-precision positioning and installation of EPS components. The UAVs are also used to conduct cruise verification of the assembled base structure, thereby improving the construction accuracy and shape controllability of free-form surface enclosure structures in terms of site adaptability, boundary control, node connection, and surface continuity.

[0022] 3) Reduce the risks of manual construction in high-altitude, low-temperature, and slippery environments. This invention transfers key operations such as site scanning, construction inspection, spraying and forming, operation monitoring, and touch-up repair to unmanned aerial vehicles and robotic arms, reducing the need for direct manual operation in high-altitude, cold, and slippery environments, and lowering the safety risks caused by high-altitude spraying, low-temperature operation, and complex curved surface construction.

[0023] 4) Enhance the continuity of the building envelope construction process and the efficiency of construction organization. This invention achieves continuous coverage of assembly construction through the arrangement of robotic arms and a track support system. It enables multi-equipment phased collaborative operation by connecting the scanning-assembly-spraying sequence under a unified coordinate reference. This reduces the interruptions caused by repeated erection and dismantling of supports, manual transportation, and experience-based adjustments in traditional construction processes, and improves the construction efficiency and controllability of free-form surface enclosure structures.

[0024] 5) Improve the operational monitorability and defect identification capability of composite ice finishes. This invention employs an unmanned aerial vehicle equipped with a non-contact scanning module to continuously acquire point cloud, image, and temperature field information of the outer surface of the cladding after the enclosure structure is formed and during operation. By comparing this information with the design model, the base structure benchmark model, and historical scanning results, it enables the identification of cracks, thinning, local thickness deficiencies, and surface continuity anomalies, thereby improving the perception capability of the enclosure structure's operational status and the timeliness of defect detection.

[0025] 6) Achieve directional repair and thickness compensation of the building envelope. This invention generates target area information for the area to be repaired or thickened based on scanning and monitoring results, and controls an unmanned aerial vehicle to perform directional spraying on the corresponding area. This causes the polymer-modified fiber-reinforced composite ice slurry to refreeze and solidify in the target area, thereby achieving crack filling, restoration of surface continuity, and local thickness compensation. Compared with overall respraying or manual local repair, this method is more conducive to reducing material consumption and maintenance interference.

[0026] 7) A closed-loop operation and maintenance mechanism This invention establishes a closed-loop operation and maintenance process of "scanning and monitoring—defect identification—target area determination—directional repair spraying—re-inspection feedback". When the re-inspection results do not meet the preset repair requirements, the system can trigger subsequent repair operations again, thereby enabling the enclosure structure to have continuous monitoring, repeated repair and dynamic maintenance capabilities, improving the long-term service stability of free-form surface enclosure structures.

[0027] 8) Form a collaborative work chain between scanning, assembly and painting. In this invention, the scanning, robotic arm assembly, and unmanned aerial vehicle (UAV) painting are not independent processes, but are carried out collaboratively under a unified construction coordinate system, a unified data interface, and a unified task scheduling relationship. The scanning results serve as the basis for site leveling and installation positioning, as well as for assembly verification, painting execution, and subsequent repairs, thus forming a collaborative work chain of "scanning for foundation building—assembling for foundation formation—painting for shell formation—monitoring and identification—touch-up painting and repair," thereby improving the integration of the entire technical system.

[0028] 9) It facilitates the promotion and application of free-form building envelope structures in prefabricated buildings. This invention clearly states that the overall shape and component shape are determined in the early stage, without relying on specific shape generation methods or single component production methods. It can be used in conjunction with different design, processing and prefabrication systems, and has good versatility and engineering adaptability. It provides a feasible technical basis for the application of prefabricated free-form building envelope structures in ice and snow buildings, public activity spaces and seasonal landscape facilities in cold regions. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0030] Figure 1 A flowchart of the overall process for the formwork-free construction and operation and maintenance of free-form building envelopes in prefabricated buildings; Figure 2 A flowchart outlining the sequential collaborative process for the formwork-free construction stages of prefabricated building free-form surface enclosure structures. Figure 3 Diagram showing the modular composition of a formworkless construction and operation system for free-form surface enclosure structures in prefabricated buildings; Figure 4 This diagram illustrates the collaborative operation of a robotic arm and an unmanned aerial vehicle during the formworkless construction phase of a prefabricated building's free-form surface enclosure structure. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] This invention proposes a template-free construction and operation system for free-form surface enclosure structures of prefabricated buildings. Based on prefabricated structural components, the method and system utilize a robotic arm to assemble discrete prefabricated units on-site. Combined with unmanned aerial vehicles (UAVs), a polymer-modified fiber-reinforced composite slurry is sprayed onto the exterior of the enclosure structure, freezing layer by layer at low temperatures to form a continuous free-form surface finish, thus achieving template-free forming of the free-form surface enclosure structure. During building operation, UAVs perform non-contact scanning and inspection of the outer surface of the enclosure structure, identifying cracks, thinning, and areas of insufficient thickness. Targeted spraying and freezing repair are then implemented in these areas, achieving condition monitoring, defect repair, and thickness compensation of the enclosure structure. This solution constructs a closed-loop technical path integrating robotic assembly, UAV spraying and forming, non-contact inspection, and targeted maintenance and repair.

[0033] Specifically, in combination Figures 1-4 This invention proposes a formwork-free construction and operation method for prefabricated building free-form surface enclosure structures, the method comprising the following steps: S1, Construction preparation, site leveling and positioning With the overall spatial form, component types, and individual component shapes of the prefabricated building's free-form surface enclosure structure already determined, the construction site is cleaned, leveled, and its foundation is positioned. An unmanned aerial vehicle (UAV) is used to perform non-contact scanning of the construction site, acquiring surface elevation and flatness information. Based on the scanning feedback, the grounding area of ​​the enclosure structure and the working area of ​​the robotic arm are leveled to ensure the grounding area meets preset flatness and uniform elevation requirements. On this basis, installation baselines and elevations for rigid components such as ring beams, as well as assembly positioning baselines for EPS components, are established.

[0034] In step S1, the unmanned aerial vehicle performs a non-contact scan of the construction site to obtain elevation and flatness information of the construction site surface. Based on the scan results, the grounding area of ​​the enclosure structure is leveled and the elevation is adjusted so that the grounding area forms an installation reference surface with a uniform elevation. On the basis of the installation reference surface, the layout area of ​​the robotic arm base, the center line of the track installation, and the installation positioning reference of the rigid components are further determined.

[0035] The arrangement area of ​​the robotic arm base is determined by combining the planar projection boundary of the freeform surface enclosure structure, the assembly sequence of EPS components, and the reachable workspace of the robotic arm, so that the robotic arm can continuously cover the target assembly area and have overlapping working ranges between adjacent arrangement stations, thereby reducing repeated relocation of the robotic arm and assembly interruptions during the construction process.

[0036] The grounding area of ​​the enclosure structure, the grounding area of ​​the robotic arm base or guide rail need to meet the flatness and elevation requirements after leveling construction. On this basis, the installation reference line, installation elevation and assembly positioning reference component of the ring beam component and the robotic arm base structure component should be established.

[0037] The track installation centerline is generated by offsetting the outer contour of the freeform surface enclosure structure outward and inward by a preset safety distance, and is continuously arranged as a segmented arc track or a closed loop track along the periphery of the enclosure structure; the installation elevation of the track is uniformly controlled based on the installation reference plane to ensure the consistency of the base height and positioning accuracy of the robotic arm when running along the track.

[0038] In frigid environments, the robotic arm preheats the base, drive units of each joint, and end effector in separate zones before starting and stopping. After reaching the preset thermal stability conditions, it performs origin reset and position calibration. After the robotic arm stops, it records the joint temperature changes and position drift. When restarting, it performs compensation control based on the shutdown duration, ambient temperature, and temperature feedback of each joint to reduce positioning errors caused by thermal expansion and contraction and changes in lubrication during low-temperature start-up and shutdown.

[0039] S2, rigid components and EPS components are assembled to form a free-form surface base structure. According to the predetermined spatial location and assembly sequence, rigid boundary components such as ring beams are first installed at the corresponding positioning references to form the boundary constraints of the free-form surface enclosure structure. Then, a robotic arm is used to grab, transport, and position the EPS components, so that each EPS component is connected to the rigid components and adjacent EPS components in sequence, gradually forming the base structure of the continuous free-form surface enclosure structure. The installation position, splicing relationship, and node connection status of the EPS components are all controlled by the preset positioning references.

[0040] The EPS components are installed sequentially according to a predetermined assembly sequence, which is determined based on the spatial position of the EPS components in the enclosure structure, their splicing relationships, construction stability requirements, and their connection relationships with the ring beam components. During the positioning and installation process, the EPS components undergo fusion calculation based on the component pose information obtained from visual sensors, laser rangefinders, and inertial measurement units to establish the relative pose relationship between the EPS components and the robotic arm end effector, the ring beam components, and other installed EPS components. The robotic arm installation trajectory is then corrected online based on the calculation results to improve the positioning accuracy of the EPS components.

[0041] S3, Assembly result verification and base structure inspection After the base structure of the enclosure structure is assembled, it is subjected to assembly verification and construction inspection. The verification and inspection include at least: spatial position verification of rigid components, splicing continuity inspection of EPS components, node connection status inspection, surface continuity inspection of the base structure of the enclosure structure, and overall stability inspection. When the verification results meet the preset requirements, the material preparation and spraying molding stage begins.

[0042] In step S3, the assembly verification and construction inspection of the base structure of the enclosure structure are carried out. The assembly verification and construction inspection include at least: spatial position verification of the ring beam components, splicing continuity inspection of EPS components, node connection status inspection, surface continuity inspection of the base structure of the enclosure structure, and overall stability inspection. The construction inspection is carried out by a collaborative operation mode of unmanned aerial vehicles (UAVs). The UAVs perform non-contact cruise scanning of the assembled base structure of the enclosure structure to obtain the spatial position, surface morphology, and splicing status information of the ring beam components, EPS components, and node areas. Based on the scanning results, assembly deviations, surface discontinuities, and local installation anomalies are identified and feedback is provided.

[0043] During construction inspection, the unmanned aerial vehicle (UAV) performs cruise scanning of the free-form surface enclosure structure and base structure, acquiring image information and / or point cloud information of the ring beam components, EPS component splicing areas and node areas, and identifying component misalignment, discontinuous splicing seams, abnormal node installation, or local surface unevenness based on the information.

[0044] S4, Slurry Formulation of Polymer-Modified Fiber-Reinforced Composite Ice Water, fiber components, and polymer components are metered, mixed, and stirred according to a preset formula to prepare a polymer-modified fiber-reinforced ice composite slurry suitable for spraying on unmanned aerial vehicles. The fiber components are used to improve the crack resistance and toughness of the composite ice material after freezing, and the polymer components are used to improve the adhesion, spraying layering performance, and overall integrity of the slurry after freezing.

[0045] In step S4, the polymer-modified fiber-reinforced composite ice slurry is prepared by water, fiber components and polymer components in a preset ratio. Water serves as the continuous phase matrix, the fiber components serve as the reinforcing phase to improve the crack resistance and toughness of the ice-based material after freezing, and the polymer components serve as the modifying phase to improve the adhesion, spraying layering performance and overall integrity of the slurry after freezing, so as to meet the requirements of unmanned aerial vehicle spraying construction and low-temperature freezing shell formation.

[0046] The proportions of the polymer-modified fiber-reinforced composite ice slurry were calculated using the mass fraction method, assuming the total mass of the slurry was [missing information]. The mass of the fiber component is The polymer component mass is The mass of water is Then the following conditions are met: The relationship between the total mass and the masses of each component satisfies:

[0047] The mass percentage of fiber components is The mass percentage of polymer components is The mass percentage of water is And satisfy Based on the preset total amount of ingredients and the mass fraction of each component, the actual mass of each component is calculated.

[0048] The formulation of the polymer-modified fiber-reinforced composite ice slurry is determined based on the following factors: ambient temperature during construction, spraying method using unmanned aerial vehicles, slurry spray flowability requirements, spray adhesion performance requirements, interlayer freezing time requirements, crack resistance requirements after freezing and molding, and overall finish requirements. Specifically, when it is necessary to improve the crack resistance and toughness of the slurry after freezing and molding, the fiber component ratio is increased; when it is necessary to improve the adhesion of the slurry to the substrate surface and the stability of the sprayed layer, the polymer component ratio is increased; when it is necessary to ensure the slurry's pumpability, atomization performance, and spray uniformity, the water ratio is adjusted.

[0049] The formulation of the polymer-modified fiber-reinforced composite ice slurry was determined by comparing the spraying performance and freeze-forming performance of different candidate formulations. The spraying performance includes at least the slurry's stirability, pumpability, sprayability, and adhesion stability. The freeze-forming performance includes at least the freezing speed, interlayer bonding, crack resistance, and shell integrity. The formulation that simultaneously meets the spraying requirements of unmanned aerial vehicles (UAVs) and the forming requirements of free-form surface enclosure structures was selected as the target formulation. After metering, mixing, and stirring, the polymer-modified fiber-reinforced composite ice slurry forms a slurry material suitable for UAV spraying.

[0050] S5, Unmanned Aerial Vehicle, Template-Free Spray Coating and Freezing Shell Formation Without using a prefabricated template, an unmanned aerial vehicle (UAV) performs a spraying operation along the outer surface of the base structure of the enclosure structure, applying the polymer-modified fiber-reinforced composite slurry to the outer surface of the enclosure structure. The slurry freezes layer by layer and is continuously stacked at low temperatures, forming a finish covering the outside of the free-form enclosure structure. Once the finish thickness reaches the preset design range, the prefabricated free-form enclosure structure is formed without a template. The base structure of the enclosure structure is a permanent supporting component after forming and is not part of the prefabricated template to be removed after construction.

[0051] S6, Non-contact scanning monitoring After the freeform surface enclosure structure is formed and during operation, an unmanned aerial vehicle is used to perform non-contact scanning monitoring on the outer surface of the cladding to obtain geometric morphology information, surface temperature information and / or thickness status information of the outer surface of the cladding, so as to characterize the operating status of the cladding.

[0052] In step S6, an unmanned aerial vehicle equipped with a non-contact scanning module is used to perform body-to-body scanning along a preset cruising path on the outer surface of the freeform surface. Under the condition of maintaining a preset working distance and scanning attitude, geometric contour data, surface temperature data and surface image data of the outer surface of the surface are collected, and the collected data are converted into geometric shape information, surface temperature information and / or thickness status information that characterize the operating state of the surface.

[0053] The non-contact scanning module includes one or more of a laser scanner, a visible light vision camera, and an infrared thermal imager. The laser scanner is used to acquire spatial point cloud data and geometric contour data of the outer surface of the finish, the visible light vision camera is used to acquire the appearance image and crack texture information of the outer surface of the finish, and the infrared thermal imager is used to acquire the temperature field distribution information of the outer surface of the finish.

[0054] During the scanning process, the unmanned aerial vehicle performs partitioned scanning of the outer surface of the decorative surface according to a preset flight speed, scanning interval, and body-fitting distance. It obtains point cloud data, image data, and temperature field data of each scanning area. After registering the data to a unified coordinate system, it compares the data with the design model data and / or historical scanning data to calculate the morphological deviation, temperature anomaly areas, and local thickness change status of the outer surface of the decorative surface, thereby characterizing the operating status of the decorative surface.

[0055] The thickness status information is obtained by comparing and analyzing the measured geometric profile of the outer surface of the finish with the designed outer surface model of the finish, the base structure benchmark model and / or the historical scanning model. It is used to characterize the degree of thinning, insufficient thickness or thickness change trend of local areas of the finish.

[0056] S7, Defect Identification and Repair Area Determination Based on the scanning and monitoring results, the condition of the outer surface of the finish is analyzed to identify cracks, thinning, insufficient local thickness, or abnormal surface continuity areas. Based on preset judgment conditions, the abnormal areas are determined as areas to be repaired or areas to be thickened.

[0057] In step S7, based on the point cloud data, appearance image data, and temperature field data acquired and registered by the UAV, anomaly identification and state determination are performed on the freeform surface finish outer surface. By comparing the measured geometric contour with the design model, the base structure benchmark model, and / or the historical scan model, cracks, thinning, insufficient local thickness, or abnormal surface continuity areas on the finish outer surface are identified. The spatial location, influence range, and defect type of the abnormal area are determined according to preset judgment conditions, and the area is divided into areas to be repaired or areas to be thickened. Target area information is generated to guide the subsequent directional spraying repair and thickness compensation by the UAV.

[0058] S8, directional touch-up repair and thickness compensation The unmanned aerial vehicle is controlled to perform directional spraying on the area to be repaired or the area to be thickened, spraying polymer-modified fiber-reinforced composite ice slurry onto the corresponding target area, and then refreezing it in a low-temperature environment to achieve crack filling, restoration of surface continuity, and local thickness compensation.

[0059] In step S8, based on the target area information generated in step S7, the unmanned aerial vehicle is controlled to perform directional spraying on the area to be repaired or the area to be thickened, and the polymer-modified fiber-reinforced composite ice slurry is sprayed onto the corresponding target area. The unmanned aerial vehicle controls the spraying path, spraying range and spraying amount according to the spatial location, boundary range, defect type and thickness compensation requirements of the target area, and makes the slurry refreeze and solidify in a low temperature environment to achieve crack filling, surface continuity restoration and local thickness compensation.

[0060] The thickness compensation requirement is determined based on the difference between the designed thickness and the current normal equivalent thickness; let the first... The design thickness of each area to be thickened is: The current normal equivalent thickness is The effective thickness increase after a single re-spraying freeze is The theoretical number of additional sprays is: in, This represents the effective thickness increment after a single touch-up spray and freezing process. For the first The theoretical number of times to re-spray the area to be thickened.

[0061] S9, Repair Result Re-inspection and Cyclic Maintenance After the targeted spraying is completed, an unmanned aerial vehicle is used to conduct non-contact scanning and monitoring of the repaired area and to re-inspect the repair results. During the operation of the enclosure structure, the steps of scanning and monitoring, defect identification, targeted spraying and re-inspection are repeated to form a cyclical maintenance mechanism for the free-form surface enclosure structure.

[0062] In step S9, after directional spraying is completed, an unmanned aerial vehicle is used to perform non-contact scanning and monitoring of the repaired area again to obtain geometric morphology information, surface temperature information and / or thickness status information of the repaired area. The re-inspection results are compared with the target area information before spraying and the preset repair requirements to determine whether the repaired area meets the requirements for crack filling, surface continuity restoration and local thickness compensation. During the operation of the enclosure structure, the steps of scanning and monitoring, defect identification, target area determination, directional spraying and re-inspection are repeated to form a closed-loop maintenance mechanism for the free-form surface enclosure structure.

[0063] In the method described, UAV scanning, robotic arm assembly, and UAV painting are carried out collaboratively according to a unified coordinate reference and phased operation logic. Specifically, the UAV first obtains site elevation, flatness, component assembly status, and surface operation status information by non-contact scanning the construction site and freeform base structure. The scanning results are used as the basis for robotic arm assembly positioning, assembly verification, UAV painting shell formation, and directional touch-up spraying repair. The robotic arm completes the positioning and assembly of rigid components and EPS components based on the installation reference established by the scanning, forming a freeform base structure. After the freeform base structure meets the preset requirements after scanning verification, the UAV performs template-free spraying on the outside of the freeform base structure and performs directional touch-up spraying on the target area based on the scanning identification results during the operation of the enclosure structure. This forms a collaborative operation chain consisting of scanning base establishment, base assembly, painting shell formation, monitoring identification, and touch-up spraying repair.

[0064] This method, based on the free-form surface shape of prefabricated buildings, coordinates multiple robotic platforms such as drones and robotic arms to achieve template-free construction of free-form surface enclosure structures. It utilizes drones to spray polymer-modified fiber-reinforced composite slurry onto the outer side of the enclosure structure's base structure, forming a continuous thin enclosure structure to complete the prefabricated building's free-form surface enclosure structure molding. During building operation, drones perform non-contact scanning and inspection of the outer surface of the enclosure structure. Based on the scanning results, cracks, thinning, or insufficient thickness areas are identified, and the drones then perform directional spraying on the corresponding areas to repair and supplement the thickness of the enclosure structure. This invention constructs a closed-loop technical solution integrating assembly molding, condition monitoring, and maintenance repair, reducing reliance on integral templates and manual high-altitude operations, and improving the safety, efficiency, and maintainability of the construction and operation of prefabricated building free-form surface enclosure structures.

[0065] This invention also proposes a formworkless construction and operation system for prefabricated building free-form surface enclosure structures, the system comprising: The site scanning and benchmark establishment module is used to perform non-contact scanning of the construction site before construction, obtain elevation and flatness information of the construction site surface, and establish a unified elevation benchmark for the grounding area of ​​the freeform surface structure, the installation benchmark line of the ring beam component, the installation elevation, and the assembly positioning benchmark of the EPS component. The robotic arm layout and track support module is used to determine the robotic arm base layout area and track installation centerline based on the planar projection boundary of the freeform surface enclosure structure, the component assembly sequence, and the reachable workspace of the robotic arm, and to form a track support system suitable for the robotic arm to run along the periphery of the freeform surface; The low-temperature operation protection module is used to implement zoned preheating, start-stop thermal stability control and position compensation control for the robot arm base, joint drive unit and end effector in extremely cold environments, so as to ensure the assembly accuracy of the robot arm under low-temperature start-stop conditions. The rigid component and EPS component assembly module is used to install rigid components such as ring beams according to the installation reference line, installation elevation and assembly positioning reference, and to use a robotic arm to grab, transport and position EPS components to form a free-form surface base structure. The assembly verification and construction inspection module is used to perform spatial position verification, splicing continuity inspection, node connection status inspection, surface continuity inspection, and overall stability inspection on the assembled freeform surface base structure. The composite slurry preparation module is used to meter, mix, and stir water, fiber components, and polymer components according to a preset ratio to prepare a polymer-modified fiber-reinforced composite ice slurry suitable for spraying on unmanned aerial vehicles. The unmanned aerial vehicle (UAV) spray coating shell module is used to control the UAV to perform spray coating operations along the outer surface of the EPS substrate structure without setting an overall molding template, so that the polymer modified fiber reinforced composite ice paste is frozen layer by layer in a low temperature environment and continuously stacked to form a free-form composite ice finish. The non-contact scanning monitoring module is used to control an unmanned aerial vehicle to carry a scanning device to perform non-contact scanning on the outer surface of the cladding after the enclosure structure is formed and during operation, so as to obtain geometric morphology information, surface temperature information and / or thickness status information of the outer surface of the cladding. The defect identification and area determination module is used to identify cracks, thinning, local insufficient thickness or abnormal surface continuity areas on the outer surface of the finish based on the scanning monitoring results, and determine them as areas to be repaired or areas to be thickened. The directional spraying repair module is used to control the unmanned aerial vehicle to perform directional spraying on the target area according to the spatial location, boundary range and defect type of the area to be repaired or thickened, so as to refreeze and mold the polymer modified fiber reinforced composite ice slurry to achieve crack filling, restoration of surface continuity and local thickness compensation. The re-inspection and cyclic maintenance module is used to perform non-contact scanning and monitoring of the repaired area again after the directional spraying is completed, and to repeat the scanning and monitoring, defect identification, directional spraying and re-inspection steps during the operation of the enclosure structure; The collaborative control module is connected to each of the above modules to establish a unified coordinate benchmark, a unified data interface, and a unified task scheduling relationship. It controls the collaborative operation of each module in the order of "site scanning and benchmark establishment - robotic arm assembly into base - assembly verification - UAV spraying into shell - scanning monitoring - defect identification - directional touch spraying - re-inspection and maintenance", thereby forming a template-free construction and operation and maintenance closed-loop system for prefabricated building free-form surface enclosure structures.

[0066] The collaborative control module is used to convert the elevation information, flatness information and installation positioning reference obtained by the site scanning and benchmark establishment module into a unified construction coordinate system, and provide the unified construction coordinate system to the robotic arm layout and track support module, the rigid component and EPS component assembly module, the assembly verification and construction inspection module, the unmanned aerial vehicle spraying shell module and the non-contact scanning and monitoring module, respectively, so as to realize unified positioning and collaboration between scanning, assembly, spraying, monitoring and repair.

[0067] The collaborative control module controls the operation of each module according to a phased operation mode. Specifically: during the construction preparation phase, the site scanning and benchmark establishment module is activated first; during the base structure formation phase, the robotic arm deployment and track support module, the low-temperature operation guarantee module, and the rigid component and EPS component assembly module are activated; after the base structure is verified to be qualified, the composite slurry preparation module and the unmanned aerial vehicle spraying shell formation module are activated; during the operation of the enclosure structure, the non-contact scanning monitoring module, the defect identification and area determination module, the directional repair spraying module, and the re-inspection and cyclic maintenance module are activated.

[0068] The scanning results obtained by the site scanning and benchmark establishment module and the non-contact scanning monitoring module serve as the positioning basis for the rigid component and EPS component assembly module, the verification basis for the assembly verification and construction inspection module, the spraying execution basis for the UAV spraying shell module, and the spraying decision basis for the directional repair module.

[0069] The rigid component and EPS component assembly module and the UAV spraying shell module adopt a coordinated approach with front and rear connections. After the robotic arm completes the assembly of the free-form surface base structure and the assembly verification and construction inspection module confirms that the spraying conditions are met, the UAV spraying shell module performs the free-form surface composite ice finish spraying operation. During the operation and maintenance phase, the UAV spraying shell module performs directional touch-up spraying repair based on the output results of the non-contact scanning monitoring module and the defect identification and area determination module.

[0070] After completing the directional respraying, the non-contact scanning and monitoring module re-inspects the repaired area and feeds back the re-inspection results to the collaborative control module. When the re-inspection results do not meet the preset repair requirements, the collaborative control module triggers the defect identification and area determination module and the directional respraying repair module again to perform subsequent repair operations, so as to form a repair closed loop.

[0071] The non-contact scanning monitoring module includes one or more of a laser scanner, a visible light vision camera, and an infrared thermal imager, used to acquire spatial point cloud data, appearance image data, and temperature field data of the outer surface of the finish, respectively.

[0072] The rigid component and EPS component assembly module includes a multi-sensor positioning unit located at the end of the robotic arm and / or the construction site. The multi-sensor positioning unit includes one or more of a visual sensor, a laser rangefinder, and an attitude detection sensor, used to identify and correct the spatial position and installation attitude of the EPS component in real time.

[0073] The low-temperature operation protection module is used to collect joint temperature, downtime and posture deviation data before and after the robotic arm starts and stops, and corrects the joint zero position deviation, trajectory start point deviation and end effector posture deviation of the robotic arm through temperature compensation algorithm, so as to improve the assembly accuracy in cold environments.

[0074] The unmanned aerial vehicle (UAV) coating and shelling module and the directional touch-up repair module are both connected to the collaborative control module. The collaborative control module controls the UAV's flight path, body-hugging distance, coating range, coating amount, and number of local repeated coatings based on the target area information.

[0075] Example This invention provides a template-free construction and operation system for prefabricated free-form surface enclosure structures, applicable to on-site construction, condition monitoring, and maintenance of free-form surface enclosure structures in cold regions or low-temperature environments. This technical solution uses a free-form surface enclosure base structure formed by assembling rigid components such as ring beams and EPS components as the supporting foundation. Through phased collaborative operations of UAV scanning, robotic arm assembly, and UAV spraying, the entire process of the enclosure structure, from construction preparation, component assembly, spraying, to operation and maintenance, is controlled. Before construction, a UAV performs a non-contact scan of the site to complete site leveling, unify elevation, and establish installation benchmarks. Subsequently, a robotic arm assembles the rigid components and EPS components to form a continuous free-form surface base structure. After assembly verification, a polymer-modified fiber-reinforced composite ice slurry is prepared and applied template-free by the UAV to the outside of the base structure, allowing the slurry to freeze layer by layer in a low-temperature environment to form a free-form surface composite ice finish. After the enclosure structure is formed and during operation, unmanned aerial vehicles continue to be used to conduct non-contact scanning and monitoring of the outer surface of the cladding, obtain information on geometric shape, surface temperature and thickness status, identify cracks, thinning and local areas with insufficient thickness, and achieve defect repair and thickness compensation through directional spraying, forming a closed-loop maintenance mechanism of "scanning-identification-spraying-re-inspection".

[0076] like Figure 1 As shown, the method of the present invention includes construction preparation and site leveling and positioning, base structure assembly and verification, composite ice slurry preparation, template-free spraying and molding of unmanned aerial vehicles, and scanning and monitoring during operation, defect identification, directional touch-up spraying and re-inspection and maintenance, forming a closed-loop technical process extending from the construction stage to the operation and maintenance stage.

[0077] In this embodiment, the overall spatial form, boundary conditions, component types, and shapes of each component of the prefabricated building free-form surface enclosure structure are determined before construction. The components include at least rigid components such as ring beams for defining boundaries and bearing boundary constraints, and EPS components for forming a continuous support surface. The initial design and production stages only provide geometric and component inputs for this invention; the invention focuses on on-site assembly, template-free spray coating, and operation and maintenance processes under a given form.

[0078] The system used in this embodiment includes: a site scanning and benchmark establishment module, a robotic arm layout and track support module, a cryogenic operation assurance module, a rigid component and EPS component assembly module, an assembly verification and construction inspection module, a composite slurry preparation module, an unmanned aerial vehicle spraying and shell forming module, a non-contact scanning and monitoring module, a defect identification and area determination module, a directional touch-up spraying and repair module, a re-inspection and cyclic maintenance module, and a collaborative control module. The collaborative control module is used to establish a unified construction coordinate system and a unified task scheduling relationship, and coordinate the operation of each module in the order of construction preparation, base assembly, shell forming, scanning and monitoring, defect identification, directional touch-up spraying, and re-inspection and maintenance.

[0079] like Figure 2 As shown, the present invention includes the following steps in the construction phase: site scanning and benchmark establishment, robotic arm deployment, rigid boundary component installation, EPS component assembly, assembly verification and inspection, composite ice slurry preparation, and UAV-based body coating and freezing molding. The site scanning results are used to establish a unified construction benchmark, and the assembly verification results are used to determine whether to proceed to the coating molding stage, thereby ensuring the sequential connection of each process in the construction phase and the controllable implementation conditions.

[0080] (1) Construction preparation, site leveling and positioning Before construction, the site was first cleared, snow removed, and obstacles cleared to create a construction area suitable for equipment access and work arrangement. Then, an unmanned aerial vehicle (UAV) equipped with a scanning module was used to perform a non-contact scan of the construction site, acquiring elevation and flatness information of the site surface and creating a three-dimensional surface model of the construction area. Based on the scanning results, the grounding areas of the freeform surface enclosure structure, the robotic arm base, and the guide rails were leveled and their elevations adjusted to meet uniform elevation and flatness requirements.

[0081] Based on this, the installation baseline and elevation of the ring beam components are established, and the assembly positioning baseline of the EPS components is also established. Combining the planar projection boundary of the freeform surface enclosure structure, the component assembly sequence, and the reachable workspace of the robotic arm, the layout area of ​​the robotic arm base and the center line of the track installation are further determined, providing a unified positional reference for subsequent robotic arm assembly.

[0082] (2) Rigid components and EPS components are assembled to form a free-form surface base structure. After establishing the construction baseline, rigid boundary components such as ring beams are first installed according to the installation baseline and installation elevation to form the boundary constraints of the free-form surface enclosure structure. After the ring beam components are installed, their spatial position serves as the boundary reference for the subsequent assembly and spraying of EPS components.

[0083] Subsequently, a robotic arm is used to grasp, transport, and position the EPS components for installation. The EPS components are installed sequentially according to a predetermined assembly sequence, determined based on their spatial position within the enclosure structure, splicing relationships, construction stability requirements, and connection relationships with the ring beam components. A multi-sensor positioning unit is installed at the end of the robotic arm and / or at the construction site to acquire the EPS component pose information through visual sensors, laser rangefinders, and inertial measurement units, and then performs fusion calculations.

[0084] Let the measured location of the EPS component be... The design location is The position error is: Let the measured attitude matrix be... The designed attitude matrix is ​​as follows Then the attitude error is: in, The measured attitude matrix of the EPS component. To design the attitude matrix, Represents the trace of a matrix. This indicates the attitude angle error. The robotic arm's installation trajectory is corrected online based on position and attitude errors to improve the positioning accuracy of EPS component installation. As EPS components are continuously installed, a continuous free-form surface enclosure base structure is gradually formed. This base structure serves both as a continuous support surface for subsequent composite ice finish spraying and freezing, and as a permanent component retained after the enclosure structure is formed.

[0085] (3) Verification of assembly results and inspection of base structure After the assembly of the freeform surface enclosure structure's base structure is completed, assembly verification and construction inspection are carried out. The inspection content includes at least: spatial position verification of ring beam components, splicing continuity inspection of EPS components, node connection status inspection, surface continuity inspection of the base structure, and overall stability inspection.

[0086] To improve verification efficiency and inspection accuracy, this embodiment introduces a collaborative construction inspection method using unmanned aerial vehicles (UAVs). Specifically, an UAV is used to perform a cruise scan of the assembled base structure, acquiring image and / or point cloud information of the ring beam components, EPS components, and node areas. The scan results are compared with the installation reference model to identify component misalignment, discontinuous joints, abnormal node installation, or uneven local surfaces. After verification that the preset requirements are met, the process proceeds to the slurry preparation and spraying stage.

[0087] (4) Preparation of polymer-modified fiber-reinforced composite ice slurry Before spraying, water, fiber components, and polymer components are metered, mixed, and stirred according to a preset ratio to prepare a polymer-modified fiber-reinforced composite ice slurry suitable for spraying on unmanned aerial vehicles. Water serves as the continuous matrix phase, and the fiber component acts as the reinforcing phase to improve the crack resistance and toughness of the composite ice material after freezing. The polymer component acts as the modifying phase to improve the slurry's adhesion, spray layering performance, and overall integrity after freezing.

[0088] Let the total mass of the slurry be The masses of water, fiber components, and polymer components are respectively , and Then the following conditions are met: The corresponding quality fractions are as follows: The target mix ratio was determined based on the ambient temperature, the spraying method for unmanned aerial vehicles (UAVs), the requirements for slurry flowability, adhesion performance, interlayer freezing time, and the overall integrity of the frozen shell. When it was necessary to improve the crack resistance and toughness after freezing, the fiber component ratio was appropriately increased; when it was necessary to improve the adhesion of the slurry to the substrate surface and the stability of the sprayed layers, the polymer component ratio was appropriately increased; when it was necessary to ensure the slurry's pumpability, atomization performance, and spray uniformity, the water ratio was adjusted. By comparing the spraying performance and freezing performance of different candidate mix ratios, the mix ratio that simultaneously met the requirements for spraying performance and shell formation was selected as the target mix ratio.

[0089] (5) Template-free spraying and freezing shell formation for unmanned aerial vehicles Without using a pre-formed template, an unmanned aerial vehicle (UAV) performs a spraying operation along the outer surface of the free-form surface enclosure structure's base, applying a polymer-modified fiber-reinforced composite ice slurry to the base structure's outer surface. During the spraying process, the UAV controls the slurry application according to a preset flight path, contact distance, and spraying attitude, allowing the slurry to freeze layer by layer and continuously stack in a low-temperature environment, gradually forming a free-form surface composite ice finish covering the outer surface of the free-form surface enclosure structure.

[0090] During the spraying process, the flight path, spraying range, and spraying amount can be adjusted according to local curvature changes, boundary positions, and the current coverage state to ensure the continuity and uniformity of the surface coverage. Once the thickness of the free-form composite ice surface reaches the preset design range, the template-free forming of the free-form enclosure structure is completed. The base structure described here is a permanent support and forming foundation, not a temporary template used to define the overall free-form surface shape; therefore, this process still falls under the template-free construction technology scheme.

[0091] (6) Non-contact scanning monitoring After the freeform surface enclosure structure is formed and during operation, an unmanned aerial vehicle (UAV) equipped with a non-contact scanning module is used to perform close-contact cruise scanning of the outer surface of the freeform surface composite ice cladding. The non-contact scanning module includes one or more of a laser scanner, a visible light vision camera, and an infrared thermal imager. During the scanning process, the UAV scans the outer surface of the cladding in sections according to a preset flight speed, scanning interval, and close-contact distance, obtaining point cloud data, image data, and temperature field data, and then uniformly registers the data to the construction coordinate system.

[0092] Based on the comparison between the measured surface model of the finish and the reference model of the substrate structure, the current thickness and thickness deviation of the local area can be calculated. Let the first... The current equivalent thickness at this location is:

[0093] in, For the first Measured points on the outer surface of the decorative finish. For the corresponding point on the base structure reference model, Let be the unit vector normal to the basis at that location. For the first The current normal equivalent thickness. Assume the design thickness at this location is The thickness deviation is: Based on the thickness deviation and combined with image data and temperature field data, geometric morphology information, surface temperature information, and thickness status information that characterize the operating state of the finish can be generated.

[0094] (7) Defect identification and repair area determination Based on point cloud data, appearance image data, and temperature field data acquired and registered by the unmanned aerial vehicle, anomalies and status determination are performed on the outer surface of the freeform composite ice veneer. Cracks can be identified through texture interruptions, edge features, and local temperature differences in visual images; thinning, insufficient local thickness, and surface continuity anomalies are identified through thickness deviations, changes in point cloud morphology, and comparison with historical scan data.

[0095] Upon identifying cracks, thinning, localized insufficient thickness, or abnormal surface continuity areas, the spatial location, influence range, and defect type of the abnormal area are determined based on preset judgment conditions, and it is then classified as an area to be repaired or an area to be thickened. Simultaneously, target area information is generated to guide subsequent directional spraying repair and thickness compensation. This target area information includes at least the target area's location coordinates, boundary range, defect type, and thickness compensation requirements.

[0096] (8) Targeted touch-up spraying repair and thickness compensation After identifying the area to be repaired or thickened, the unmanned aerial vehicle (UAV) is controlled to fly to the corresponding target area and perform directional spraying based on the target area information generated in step S7. The UAV controls the spraying path, spraying range, spraying amount, and number of local re-spraying operations according to the spatial location, boundary range, defect type, and thickness compensation requirements of the target area, spraying the polymer-modified fiber-reinforced composite slurry onto the corresponding target area.

[0097] For the area to be thickened, let the design thickness be... The current thickness is The required compensation thickness for:

[0098] If the effective thickness increment formed by a single spray is The theoretical number of additional sprays is: in, This represents the effective thickness increment after a single touch-up spray and freezing process. For the first The theoretical number of times to re-spray the area to be thickened. Based on this, the unmanned aerial vehicle is controlled to perform directional spraying on the target area, so that the polymer-modified fiber-reinforced composite ice slurry is re-frozen and molded in a low-temperature environment to achieve crack filling, restoration of surface continuity and local thickness compensation.

[0099] (9) Re-inspection of repair results and cyclical maintenance After the targeted spraying is completed, an unmanned aerial vehicle is used to conduct non-contact scanning and monitoring of the repaired area to obtain geometric morphology, surface temperature and thickness information of the repaired area. The re-inspection results are compared with the target area information and preset repair requirements before spraying to determine whether the repaired area meets the requirements for crack filling, restoration of surface continuity and local thickness compensation.

[0100] During the operation of the enclosure structure, the steps of scanning and monitoring, defect identification, target area determination, directional spraying, and re-inspection are repeatedly executed, forming a closed-loop maintenance mechanism for the free-form surface enclosure structure. When the re-inspection results do not meet the preset requirements, the system can trigger the defect identification and area determination module and the directional spraying repair module again to perform subsequent repair work, thereby forming a continuous feedback operation and maintenance closed loop.

[0101] (10) System Cooperative Control Logic In this embodiment, the collaborative control module is used to establish a unified coordinate reference, a unified data interface, and a unified task scheduling relationship, enabling UAV scanning, robotic arm assembly, and UAV painting to be carried out collaboratively according to a phased operation logic. This collaboration does not emphasize simultaneous construction by different devices in the same space, but rather emphasizes sequential connection and feedback control under a unified coordinate and data chain.

[0102] like Figure 3 As shown, the system of this invention consists of a site scanning and benchmark establishment module, a robotic arm layout and track support module, a low-temperature operation assurance module, a rigid component and EPS component assembly module, an assembly verification and construction inspection module, a composite slurry preparation module, an unmanned aerial vehicle spraying and shell forming module, a non-contact scanning and monitoring module, a defect identification and area determination module, a directional touch-up spraying and repair module, a re-inspection and cyclic maintenance module, and a collaborative control module. All modules are sequentially connected under a unified construction coordinate system and a unified task scheduling relationship, and data integration and feedback control are achieved through scanning results, assembly results, and repair results.

[0103] Specifically, during the construction preparation phase, the UAV prioritizes site scanning and benchmark establishment, providing a unified construction coordinate system and positioning benchmark for the robotic arm assembly. During the base structure formation phase, the robotic arm assembles rigid components and EPS components based on the aforementioned positioning benchmark. After the base structure assembly is completed, the UAV scans and verifies it, and performs external shell coating after the verification meets the requirements. During the operation and maintenance phase, the UAV continues to perform scanning and monitoring of the outer surface of the finish, triggering defect determination, target area generation, directional touch-up spraying, and re-inspection feedback based on the monitoring and identification results. This forms a collaborative work chain of "scanning and base establishment—assembling into a base—coating into a shell—monitoring and identification—touch-up repair—re-inspection feedback."

[0104] like Figure 4 As shown, in one embodiment of the present invention, multiple robotic arms are arranged on tracks or fixed positions around the outer perimeter of the enclosure structure, respectively undertaking the tasks of installing rigid boundary components such as ring beams and positioning and assembling EPS components; multiple unmanned aerial vehicles (UAVs) are located in the airspace above the enclosure structure, respectively undertaking tasks such as assembly verification cruise scanning, external composite ice slurry spraying, and operational verification and inspection. The robotic arms are used to form a continuous free-form surface base structure, and the UAVs perform body-fit spraying and subsequent scanning and inspection on the outside of the base structure, thereby achieving the forming and maintenance of the free-form surface enclosure structure without setting an overall forming template. The robotic arm assembly and UAV operation adopt a phased and functional collaborative implementation method: in the base structure formation stage, robotic arm assembly is the main method, and UAV verification is secondary; in the surface forming and operation and maintenance stage, UAV spraying and scanning are the main methods, thus forming a collaborative operation chain of "scanning base construction—assembling base—spraying shell formation—monitoring and identification—touch spraying and repair".

[0105] This invention provides a formworkless construction and operation system for free-form surface enclosure structures in prefabricated buildings. Under the premise that the overall spatial form and component forms are already determined, this technical solution uses a free-form surface base structure formed by assembling rigid components such as ring beams and EPS components as the supporting foundation. Through phased collaborative operations of unmanned aerial vehicle (UAV) scanning, robotic arm assembly, and UAV spraying, it achieves full-process control of the free-form surface enclosure structure from construction preparation, base assembly, formworkless forming to operation and maintenance.

[0106] Compared to existing construction methods that rely on monolithic templates, manual high-altitude spraying, or experience-based construction organization, this invention first utilizes an unmanned aerial vehicle (UAV) to scan the construction site, provide leveling feedback, and establish installation benchmarks. Then, a robotic arm positions and assembles rigid and EPS components according to a pre-set assembly sequence, forming a continuous free-form surface base structure. Based on this, the UAV sprays polymer-modified fiber-reinforced composite ice slurry onto the outer side of the base structure without using a monolithic template. The slurry freezes layer by layer at low temperatures, forming a free-form composite ice finish, thereby improving geometric control, construction continuity, and on-site implementation efficiency during the construction of complex curved surface enclosure structures.

[0107] During the operation and maintenance phase, this invention continues to employ unmanned aerial vehicles (UAVs) to perform non-contact scanning and monitoring of the outer surface of the composite ice finish, acquiring information on its geometric shape, surface temperature, and thickness. This information is then compared with the design model, the base structure benchmark model, and historical scanning results to identify cracks, thinning, areas of insufficient local thickness, and areas with abnormal surface continuity. Based on this, target area information for areas to be repaired or thickened is generated, and the UAV performs directional spraying, causing the polymer-modified fiber-reinforced composite ice slurry to refreeze and solidify in the target area. This achieves crack filling, restoration of finish continuity, and local thickness compensation, thus forming a closed-loop operation and maintenance mechanism of "scanning monitoring—defect identification—directional spraying—re-inspection feedback."

[0108] Through the above technical solutions, this invention organically integrates site scanning and benchmark establishment, high-precision assembly of robotic arms under low-temperature conditions, template-free spraying and molding of unmanned aerial vehicles, and non-contact monitoring and repair during operation, and constructs an integrated technical system suitable for the construction and maintenance of free-form surface enclosure structures in cold regions. It provides a feasible engineering implementation path for the safe construction, continuous molding, condition perception, and sustainable maintenance of prefabricated building free-form surface enclosure structures.

[0109] The foregoing has provided a detailed description of the template-free construction and operation and maintenance method and system for prefabricated building free-form surface enclosure structures proposed in this invention. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this invention. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A method for the formwork-free construction and operation and maintenance of a prefabricated building free-form surface enclosure structure, characterized in that, The method includes the following steps: S1, Construction preparation, site leveling and positioning With the overall spatial form, component types, and individual component shapes of the prefabricated building's free-form surface enclosure structure already determined, the construction site is cleaned, leveled, and its foundation is positioned. An unmanned aerial vehicle (UAV) is used to perform non-contact scanning of the construction site, acquiring surface elevation and flatness information. Based on the scanning feedback, the grounding area of ​​the enclosure structure and the working area of ​​the robotic arm are leveled to ensure the grounding area meets preset flatness and uniform elevation requirements. On this basis, installation baselines and elevations for rigid components, as well as assembly positioning baselines for EPS components, are established. S2, rigid components and EPS components are assembled to form a free-form surface base structure. According to the predetermined spatial location and assembly sequence, the rigid components are first installed at the corresponding positioning reference to form the boundary constraint of the free-form surface enclosure structure; then, the robotic arm is used to grab, transport and position the EPS components, so that each EPS component is connected to the rigid component and adjacent EPS components in sequence, gradually forming the base structure of the continuous free-form surface enclosure structure. The installation position, splicing relationship and node connection status of the EPS components are all controlled by the preset positioning reference. S3, Assembly result verification and base structure inspection After the base structure of the enclosure structure is assembled, it is subjected to assembly verification and construction inspection. The verification and inspection include at least: spatial position verification of rigid components, splicing continuity inspection of EPS components, node connection status inspection, surface continuity inspection of the base structure of the enclosure structure, and overall stability inspection. When the verification results meet the preset requirements, the material preparation and spraying molding stage begins. S4, Slurry Formulation of Polymer-Modified Fiber-Reinforced Composite Ice Water, fiber components, and polymer components are metered, mixed, and stirred according to a preset formula to prepare a polymer-modified fiber-reinforced ice composite slurry suitable for spraying on unmanned aerial vehicles. The fiber components are used to improve the crack resistance and toughness of the composite ice material after freezing, and the polymer components are used to improve the adhesion, spraying layering performance, and overall integrity of the slurry after freezing. S5, Unmanned Aerial Vehicle, Template-Free Spray Coating and Freezing Shell Formation Without setting an integral molding template, an unmanned aerial vehicle is used to perform a spraying operation along the outer surface of the base structure of the enclosure structure, spraying the polymer-modified fiber-reinforced composite ice slurry onto the outer surface of the enclosure structure; the slurry freezes layer by layer and is continuously stacked in a low-temperature environment to form a finish covering the outside of the free-form enclosure structure; when the thickness of the finish reaches the preset design range, the templateless molding of the prefabricated building free-form enclosure structure is completed; the base structure of the enclosure structure is a permanent supporting component after molding and is not an integral molding template to be removed after construction; S6, Non-contact scanning monitoring After the freeform surface enclosure structure is formed and during operation, an unmanned aerial vehicle is used to perform non-contact scanning monitoring on the outer surface of the cladding to obtain geometric morphology information, surface temperature information and / or thickness status information of the outer surface of the cladding, so as to characterize the operating status of the cladding. S7, Defect Identification and Repair Area Determination Based on the scanning and monitoring results, the condition of the outer surface of the finish is analyzed to identify cracks, thinning, local insufficient thickness or abnormal surface continuity areas, and the abnormal areas are determined as areas to be repaired or areas to be thickened according to preset judgment conditions. S8, directional touch-up repair and thickness compensation The unmanned aerial vehicle is controlled to perform directional spraying on the area to be repaired or the area to be thickened, and the polymer modified fiber reinforced composite ice slurry is sprayed onto the corresponding target area and then re-frozen and molded in a low temperature environment to achieve crack filling, restoration of surface continuity and local thickness compensation. S9, Repair Result Re-inspection and Cyclic Maintenance After the targeted spraying is completed, an unmanned aerial vehicle is used to conduct non-contact scanning and monitoring of the repaired area and to re-inspect the repair results. During the operation of the enclosure structure, the steps of scanning and monitoring, defect identification, targeted spraying and re-inspection are repeated to form a cyclical maintenance mechanism for the free-form surface enclosure structure.

2. The method according to claim 1, characterized in that, In step S1, the robot arm base layout area, track installation center line, and rigid component installation positioning reference are further determined. The robot arm base layout area is determined jointly based on the planar projection boundary of the freeform surface enclosure structure, the assembly sequence of EPS components, and the reachable work space of the robot arm, so that the robot arm can continuously cover the target assembly area and have overlapping working ranges between adjacent layout stations, thereby reducing repeated displacement and assembly interruption of the robot arm during construction.

3. The method according to claim 1, characterized in that, In step S2, the EPS components are installed sequentially according to a predetermined assembly sequence, which is determined based on the spatial position of the EPS components in the enclosure structure, splicing relationship, construction stability requirements, and connection relationship with rigid components.

4. The method according to claim 1, characterized in that, In step S3, the construction inspection is carried out using a collaborative operation mode of unmanned aerial vehicles. The unmanned aerial vehicle performs non-contact cruise scanning on the assembled enclosure base structure to obtain the spatial position, surface morphology and splicing status information of rigid components, EPS components and node areas, and identifies and provides feedback on assembly deviations, surface discontinuities and local installation anomalies based on the scanning results.

5. The method according to claim 1, characterized in that, In step S4, the proportion of the polymer-modified fiber-reinforced composite ice slurry is calculated using the mass fraction method, assuming the total mass of the slurry is... The mass of the fiber component is The polymer component mass is The mass of water is Then the following condition is met: The relationship between the total mass and the masses of each component satisfies: The mass percentage of fiber components is The mass percentage of polymer components is The mass percentage of water is And satisfy Based on the preset total amount of ingredients and the mass fraction of each component, the actual mass of each component is calculated.

6. The method according to claim 5, characterized in that, The formulation of the polymer-modified fiber-reinforced composite ice slurry is determined based on the following factors: ambient temperature during construction, spraying method using unmanned aerial vehicles, slurry spray flowability requirements, spray adhesion performance requirements, interlayer freezing time requirements, crack resistance requirements after freezing and molding, and overall finish requirements. Specifically, when it is necessary to improve the crack resistance and toughness of the slurry after freezing and molding, the fiber component ratio is increased; when it is necessary to improve the adhesion of the slurry to the substrate surface and the stability of the sprayed layer, the polymer component ratio is increased; when it is necessary to ensure the slurry's pumpability, atomization performance, and spray uniformity, the water ratio is adjusted.

7. The method according to claim 1, characterized in that, In step S6, an unmanned aerial vehicle equipped with a non-contact scanning module is used to perform body-to-body scanning along a preset cruising path on the outer surface of the freeform surface. Under the condition of maintaining a preset working distance and scanning attitude, geometric contour data, surface temperature data and surface image data of the outer surface of the surface are collected, and the collected data are converted into geometric shape information, surface temperature information and / or thickness status information that characterize the operating state of the surface.

8. The method according to claim 1, characterized in that, In step S7, based on the point cloud data, appearance image data, and temperature field data acquired and registered by the UAV, anomaly identification and state determination are performed on the freeform surface finish outer surface. By comparing the measured geometric contour with the design model, the base structure benchmark model, and / or the historical scan model, cracks, thinning, insufficient local thickness, or abnormal surface continuity areas on the finish outer surface are identified. The spatial location, influence range, and defect type of the abnormal area are determined according to preset judgment conditions, and the area is divided into areas to be repaired or areas to be thickened. Target area information is generated to guide the subsequent directional spraying repair and thickness compensation by the UAV.

9. The method according to claim 8, characterized in that, In step S8, based on the target area information generated in step S7, the unmanned aerial vehicle is controlled to perform directional spraying on the area to be repaired or the area to be thickened, and the polymer-modified fiber-reinforced composite ice slurry is sprayed onto the corresponding target area. The unmanned aerial vehicle controls the spraying path, spraying range, and spraying amount according to the spatial location, boundary range, defect type, and thickness compensation requirements of the target area, and makes the slurry refreeze and solidify in a low-temperature environment to achieve crack filling, surface continuity restoration, and local thickness compensation.

10. A formworkless construction and operation system for prefabricated building free-form surface enclosure structures, characterized in that, The system includes: The site scanning and benchmark establishment module is used to perform non-contact scanning of the construction site before construction, obtain elevation and flatness information of the construction site surface, and establish a unified elevation benchmark for the grounding area of ​​the freeform surface structure, the installation benchmark line of the ring beam component, the installation elevation, and the assembly positioning benchmark of the EPS component. The robotic arm layout and track support module is used to determine the robotic arm base layout area and track installation centerline based on the planar projection boundary of the freeform surface enclosure structure, the component assembly sequence, and the reachable workspace of the robotic arm, and to form a track support system suitable for the robotic arm to run along the periphery of the freeform surface; The low-temperature operation protection module is used to implement zoned preheating, start-stop thermal stability control and position compensation control for the robot arm base, joint drive unit and end effector in extremely cold environments, so as to ensure the assembly accuracy of the robot arm under low-temperature start-stop conditions. The rigid component and EPS component assembly module is used to install the ring beam rigid component according to the installation datum line, installation elevation and assembly positioning datum, and to use a robotic arm to grab, transport and position the EPS component to form a free-form surface base structure. The assembly verification and construction inspection module is used to perform spatial position verification, splicing continuity inspection, node connection status inspection, surface continuity inspection, and overall stability inspection on the assembled free-form surface base structure. The composite slurry preparation module is used to meter, mix, and stir water, fiber components, and polymer components according to a preset ratio to prepare a polymer-modified fiber-reinforced composite ice slurry suitable for spraying on unmanned aerial vehicles. The unmanned aerial vehicle (UAV) spray coating shell module is used to control the UAV to perform spray coating operations along the outer surface of the EPS substrate structure without setting an overall molding template, so that the polymer modified fiber reinforced composite ice paste is frozen layer by layer in a low temperature environment and continuously stacked to form a free-form composite ice finish. The non-contact scanning monitoring module is used to control an unmanned aerial vehicle to carry a scanning device to perform non-contact scanning on the outer surface of the cladding after the enclosure structure is formed and during operation, so as to obtain geometric morphology information, surface temperature information and / or thickness status information of the outer surface of the cladding. The defect identification and area determination module is used to identify cracks, thinning, local insufficient thickness or abnormal surface continuity areas on the outer surface of the finish based on the scanning monitoring results, and determine them as areas to be repaired or areas to be thickened. The directional spraying repair module is used to control the unmanned aerial vehicle to perform directional spraying on the target area according to the spatial location, boundary range and defect type of the area to be repaired or thickened, so as to refreeze and mold the polymer modified fiber reinforced composite ice slurry to achieve crack filling, restoration of surface continuity and local thickness compensation. The re-inspection and cyclic maintenance module is used to perform non-contact scanning and monitoring of the repaired area again after the directional spraying is completed, and to repeat the scanning and monitoring, defect identification, directional spraying and re-inspection steps during the operation of the enclosure structure; The collaborative control module is connected to each of the above modules to establish a unified coordinate benchmark, a unified data interface, and a unified task scheduling relationship. It controls the collaborative operation of each module in the order of "site scanning and benchmark establishment - robotic arm assembly into base - assembly verification - UAV spraying into shell - scanning monitoring - defect identification - directional touch spraying - re-inspection and maintenance", thereby forming a template-free construction and operation and maintenance closed-loop system for prefabricated building free-form surface enclosure structures.

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