Intelligent active damping and noise reduction interior panel for suborbital space tourism vehicles

Abstract

A smart active vibration damping and noise reduction interior panel for a suborbital space tourism spacecraft belongs to the field of spacecraft structural design and vibration and noise control technology. It includes a composite structure and an active control system. In the composite structure: a lower panel secures the interior panel to the cabin; the upper panel is a visible decorative panel inside the spacecraft cabin; the core functional layer uses dynamically responsive functional materials to absorb noise and dissipate vibration energy during dynamic regulation. In the active control system: a vibration sensor network is distributed across the spacecraft cabin structure and the composite structure to monitor vibration and frequency; a central controller receives measurement data from the vibration sensor network, analyzes the dominant frequency and amplitude, and generates an optimal control signal; actuators are configured according to the dynamically responsive functional materials of the core functional layer and execute the control signals from the central controller to dynamically regulate the dynamically responsive functional materials. This invention effectively suppresses structural vibration propagation and radiated noise, providing a quiet and stable cabin environment for occupants.

Description

Technical Field

[0001] This invention relates to an intelligent active vibration reduction and noise reduction interior panel for a suborbital space tourism spacecraft, and more particularly to a spacecraft interior panel based on functional materials (phase change material PCM or smart fluid) that can actively adapt to external excitation for adaptive vibration reduction and noise reduction, belonging to the field of spacecraft structural design and vibration and noise control technology. Background Technology

[0002] Suborbital flight is accompanied by extremely harsh vibration and noise environments, such as low-frequency, high-amplitude vibrations generated by engines and high-frequency noise caused by aerodynamic turbulence. These NVH (Noise, Vibration, and Harshness) problems reduce crew comfort, affect crew health, and interfere with cabin equipment. Traditional passive methods for NVH control in spacecraft cabins (such as damping films, sound insulation cotton, and dynamic vibration absorbers) have problems such as large added weight, fixed frequency band, and poor adaptability. They cannot meet the weight and capacity requirements of commercial spaceflight, cannot cover wide-band excitation, and cannot cope with the changing vibration and noise spectrum at different stages of flight. Therefore, there is an urgent need for a lightweight, adaptive, wide-bandwidth intelligent vibration reduction and noise reduction solution. Summary of the Invention

[0003] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide an intelligent active vibration reduction and noise reduction interior panel for suborbital space tourism spacecraft. It uses phase change materials or smart fluids as core functional materials to solve the problem that the prior art cannot effectively suppress the propagation of structural vibration and radiated noise, and cannot provide the occupants with an extremely quiet and stable cabin environment.

[0004] The technical solution of this invention is: an intelligent active vibration reduction and noise reduction interior panel for suborbital space tourism spacecraft, comprising: a composite structure and an active control system; wherein: The composite structure consists of the following components from the outside to the inside: a lower panel, a core functional layer, and an upper panel. The lower panel is connected to the spacecraft cabin structure and is used to fix the interior panels to the cabin. The upper panel is a decorative panel visible on the inside of the spacecraft cabin, serving both decorative and protective functions. The core functional layer uses functional materials and absorbs noise and consumes vibration energy by dynamically adjusting the reversible changes in its physical state. The active control system includes a vibration sensing network, a central controller, and actuators. The vibration sensing network is distributed on the spacecraft cabin structure and composite structure to monitor vibration and frequency in real time. The central controller receives the measurement data from the vibration sensing network, analyzes the vibration signals in real time, and generates corresponding control commands. The actuators are set according to the functional materials of the core functional layer, receive and execute the control commands of the central controller, and dynamically control the functional materials.

[0005] Preferably, the core functional layer includes a phase change material (PCM) sublayer and a smart fluid sublayer, arranged spatially between the bottom panel and the top panel in an order from the outside to the inside; specifically: A phase change material is encapsulated in a PCM sublayer. The phase change material undergoes a solid-liquid phase transition at a corresponding phase transition temperature, and vibrations are damped during the phase transition. This is used to suppress low-frequency vibrations, which are 0.5Hz to 30Hz, during the emission phase. The intelligent fluid is encapsulated in the intelligent fluid sublayer. The intelligent fluid undergoes a reversible change in rheological properties under the action of an external magnetic field or electric field. During the change in rheological properties, vibration is attenuated and noise is absorbed. It is used to suppress high-frequency vibration and aerodynamic noise during the reentry phase. The high-frequency vibration is 500Hz~1000Hz.

[0006] Preferably, the actuator in the active control system includes a thermoelectric cooler placed in a phase change material.

[0007] Preferably, the active control system dynamically regulates the functional materials, specifically as follows: When the vibration sensing network detects a low-frequency vibration signal, it collects and outputs the signal to the central controller. The central controller receives vibration signals transmitted by sensors, identifies the dominant frequency, queries the built-in database, determines the optimal operating state of the phase change material at the current dominant frequency and the temperature corresponding to the optimal operating state, generates a temperature control command and sends it to the thermoelectric cooling plate. The thermoelectric cooling plate executes the temperature control command to heat or cool the phase change material, keeping the temperature of the phase change material at the phase change point, converting the mechanical energy of vibration into heat energy, and achieving vibration attenuation.

[0008] Preferably, the smart fluid includes magnetorheological fluid and electrorheological fluid; the rheological properties include viscosity and shear modulus.

[0009] Preferably, the actuators in the active control system include electromagnetic coils or electrode plates placed in the smart fluid.

[0010] Preferably, the active control system dynamically regulates the functional materials, specifically as follows: The vibration sensing network monitors the vibration and outputs the high-frequency vibration signal to the central controller. The central controller receives high-frequency vibration signals transmitted by sensors, determines the structural damping required to suppress the high-frequency resonance, determines the magnitude of the current to be applied to the actuator, and generates a current regulation command to send to the actuator. The actuator executes the current regulation command to adjust the viscosity of the smart fluid and increase the shear modulus of the smart fluid, thereby suppressing vibration and its radiated noise.

[0011] Preferably, the vibration sensing network includes accelerometers or fiber optic strain sensors distributed on the cabin structure and interior panels.

[0012] Compared with the prior art, the present invention has the following advantages: This invention changes the traditional passive sound insulation method, enabling it to sense external stimuli and actively adjust its own properties. It can effectively suppress broadband, time-varying vibration noise, with vibration reduction and noise reduction effects far exceeding those of passive materials, and has the advantage of active self-adaptation. At the same time, it replaces multiple layers of passive materials with a single intelligent material layer, significantly reducing the system weight while achieving better NVH performance, meeting the stringent weight reduction requirements of aerospace, and combining high efficiency and lightweight characteristics. In addition, the interior panel is not only a structural component and a decorative component, but also a vibration reduction and noise reduction functional component, achieving a highly integrated multi-functional effect. Moreover, the system can call different control strategies for different flight stages (with different vibration spectra) to always provide optimal performance, and has adjustable performance capabilities. Attached Figure Description

[0013] Figure 1 This is an exploded view of the sandwich structure of the intelligent interior panel of the present invention; Figure 2 This is a block diagram illustrating the closed-loop control principle of the system of the present invention. Detailed Implementation

[0014] To address the problem that existing technologies cannot effectively suppress structural vibration propagation and radiated noise, the present invention adopts the following technical solution: An intelligent active vibration damping and noise reduction interior panel, its innovation lies in its sandwich composite structure and active control system, such as... Figure 1 As shown, it specifically includes: The sandwich composite structure consists of a lower panel, a core functional layer, and an upper panel, arranged from the outside in. The lower panel connects to the spacecraft cabin structure, securing the interior panels to the cabin. The core functional layer is the core of this invention, divided into a phase change material (PCM) sublayer and a smart fluid sublayer, both encapsulating functional materials. The PCM sublayer uses encapsulated paraffin-based phase change material, which undergoes a solid-liquid phase transition at a specific temperature, absorbing significant noise and consuming vibration energy (latent heat) during the transition. When the phase change material is encapsulated paraffin-based, the specific temperature is 30°C to 35°C. The smart fluid sublayer uses magnetorheological or electrorheological fluids, whose rheological properties (viscosity, shear modulus) can undergo rapid, reversible, and dramatic changes under the influence of an external magnetic or electric field. The upper panel is a decorative panel visible on the interior side of the cabin, serving both decorative and protective functions.

[0015] The specific configuration of phase change materials and smart fluids in the core functional layer is as follows: The core functional layer is divided into a phase change material (PCM) sublayer and a smart fluid sublayer. The PCM sublayer is used to suppress low-frequency vibrations (0.5Hz~30Hz) generated during the emission phase, while the smart fluid sublayer is used to suppress high-frequency vibrations (500Hz~1000Hz) generated during the reentry phase. After the PCM sublayer and the smart fluid sublayer are independently packaged, they are arranged in space from the outside to the inside between the bottom panel and the top panel, without the need for isolation in between.

[0016] Active control systems, such as Figure 2 The system includes: a vibration sensing network, a central controller, and actuators. The vibration sensing network consists of accelerometers or fiber optic strain sensors distributed on the cabin structure and interior panels, used to monitor vibration acceleration and frequency in real time, providing data support for subsequent control. The central controller receives sensor data transmitted from the vibration sensing network and incorporates adaptive filtering algorithms, fuzzy control algorithms, and other control algorithms to analyze the dominant vibration frequency and amplitude in real time and generate the optimal control signal. The actuators are configured according to different sub-layers of the core functional layer, specifically: For the phase change material (PCM) sublayer, the actuator is a thermoelectric heating / cooling plate integrated in the PCM sublayer. The central controller precisely controls the changes of the PCM near the solid / liquid phase by controlling the temperature, thereby maximizing its damping energy dissipation effect. For the smart fluid sublayer, the actuator is an electromagnetic coil or electrode plate embedded in the smart fluid sublayer. The central controller adjusts the viscosity and modulus of the smart fluid in real time and continuously by changing the current (magnetic field) of the input coil or the voltage (electric field) between the electrodes, thereby changing the stiffness and damping characteristics of the entire sandwich structure.

[0017] A smart control method based on the aforementioned interior trim panel includes the following steps: S1: Vibration sensing network collects structural vibration data in real time; S2: The central controller analyzes the data and identifies the main oscillation frequency and the frequency band where energy is concentrated; S3: The central controller calculates and outputs targeted control signals based on the built-in algorithm; S4: Execute control actions based on different sub-layers of the core functional layer: For the PCM sublayer: The central controller drives the thermoelectric element through the control signal to locally heat or cool the PCM sublayer, so that the PCM works near the phase change point and reaches the optimal energy absorption state. For the intelligent fluid sublayer: The central controller drives the electromagnetic coil or electrode plate through control signals to generate a corresponding magnetic field or electric field, which changes the viscosity / modulus of the intelligent fluid, thereby "hardening" or "softening" the interior panel and specifically suppressing vibration in this frequency band; S5: The system forms a closed-loop control process of "perception-analysis-control" to continuously and adaptively optimize the vibration reduction and noise reduction effect, ensuring a quiet and stable cabin environment.

[0018] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0019] Example Phase change material (PCM) sublayer: Suppresses low-frequency vibrations during launch. This embodiment addresses the scenario where the engine generates strong low-frequency vibrations during spacecraft launch. The specific implementation steps are as follows: S1: Sensing. Accelerometers distributed on the cabin structure and interior panels are activated to monitor vibration data in real time, detecting low-frequency vibration signals in the range of 0.5Hz-30Hz.

[0020] S2: Decision. The central controller receives vibration data transmitted from the sensors, identifies the dominant frequency, and determines the optimal operating state of the phase change material (PCM) at the current dominant frequency as a "solid-liquid mixed phase" by querying the built-in database.

[0021] S3: Execution. The controller precisely controls the thermoelectric element integrated in the corresponding area of ​​the interior panel to heat the phase change material (PCM) capsule, keeping its temperature at the phase change point, in a solid-liquid coexistence state.

[0022] S4: Effect. A significant amount of vibrational energy is consumed by disrupting the crystal structure of the phase change material PCM (resulting in a phase change), rather than being transmitted through the structure, thus significantly reducing the vibrational amplitude transmitted into the crew cabin.

[0023] Intelligent fluid sublayer: Suppressing aerodynamic noise during reentry. This embodiment addresses the scenario where aerodynamic turbulence causes high-frequency vibration and radiated noise in the interior panels during spacecraft reentry into the atmosphere. The specific implementation steps are as follows: S1: Sensing. The fiber optic strain sensor in the vibration sensing network is activated, detects high-frequency vibration signals of 500-1000Hz, and transmits the data to the central controller.

[0024] S2: Decision. The central controller analyzes the received high-frequency vibration data and determines whether to suppress high-frequency resonance in this frequency band by increasing structural damping.

[0025] S3: Execution. The central controller applies a current of a specific intensity to the electromagnetic coil embedded in the smart fluid sublayer cellular cell, causing the coil to generate a corresponding magnetic field.

[0026] S4: Effect. The viscosity of the intelligent fluid instantly increases to a near-solid state, significantly improving the shear modulus and damping loss factor of the core layer, thereby greatly enhancing the structural damping of the interior panel and effectively suppressing high-frequency vibrations and their radiated noise.

[0027] The above description is merely an illustrative embodiment of the present invention and is not intended to limit the scope of the invention. Any equivalent changes, modifications, and combinations made by those skilled in the art without departing from the concept and principles of the present invention should fall within the scope of protection of the present invention.

[0028] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

Claims

1. A smart active vibration damping and noise reduction interior panel for a suborbital space tourism spacecraft, characterized in that... include: Composite structure and active control system; wherein: The composite structure consists of the following components from the outside to the inside: a lower panel, a core functional layer, and an upper panel. The lower panel is connected to the spacecraft cabin structure and is used to fix the interior panels to the cabin. The upper panel is a decorative panel visible on the inside of the spacecraft cabin, serving both decorative and protective functions. The core functional layer uses functional materials and absorbs noise and consumes vibration energy by dynamically adjusting the reversible changes in its physical state. The active control system includes a vibration sensing network, a central controller, and actuators. The vibration sensing network is distributed on the spacecraft cabin structure and composite structure to monitor vibration and frequency in real time. The central controller receives the measurement data from the vibration sensing network, analyzes the vibration signals in real time, and generates corresponding control commands. The actuators are set according to the functional materials of the core functional layer, receive and execute the control commands of the central controller, and dynamically control the functional materials. The core functional layer includes a phase change material (PCM) sublayer and a smart fluid sublayer, arranged spatially between the bottom and top panels in an order from the outside to the inside; specifically: A phase change material (PCM) sublayer is encapsulated within the PCM sublayer. This PCM undergoes a solid-liquid phase transition at a corresponding phase transition temperature, damping vibrations during the phase transition process. This damping is used to suppress low-frequency vibrations (0.5Hz~30Hz) during the launch phase. A smart fluid sublayer is encapsulated within the PCM sublayer. This smart fluid undergoes a reversible change in its rheological properties under the influence of an external magnetic or electric field. During this rheological property change, vibrations are damped and noise is absorbed. This smart fluid is used to suppress high-frequency vibrations and aerodynamic noise (500Hz~1000Hz) during the reentry phase. The phase change material is a capsuled paraffin-based phase change material, which undergoes a solid-liquid phase change at a specific temperature. The phase change process absorbs noise and consumes vibration energy. When the phase change material is a capsuled paraffin-based material, the specific temperature is 30℃~35℃. After the phase change material (PCM) sublayer and the smart fluid sublayer are encapsulated independently, they are arranged in space from the outside to the inside between the bottom panel and the top panel, without the need for isolation in between. The actuators in the active control system include thermoelectric cooling plates placed in the phase change material; The active control system dynamically regulates the functional materials, specifically as follows: When the vibration sensing network detects a low-frequency vibration signal, it collects and outputs the signal to the central controller. The central controller receives vibration signals transmitted by the sensors, identifies the main vibration frequency, queries the built-in database, determines the optimal working state of the phase change material at the current main vibration frequency and the temperature corresponding to the optimal working state, generates a temperature control command and sends it to the thermoelectric cooling plate. The thermoelectric cooling plate executes the temperature control command to heat or cool the phase change material, keeping the temperature of the phase change material at the phase change point, in a solid-liquid coexistence state, converting the mechanical energy of vibration into heat energy, and realizing vibration attenuation. The intelligent fluid includes magnetorheological fluid and electrorheological fluid; the rheological properties include viscosity and shear modulus. The actuators in the active control system include electromagnetic coils or electrode plates placed in the smart fluid; The active control system dynamically regulates the functional materials. Specifically, the vibration sensor network monitors the vibration and outputs the high-frequency vibration signal to the central controller. The central controller receives high-frequency vibration signals transmitted by sensors, determines the structural damping required to suppress the high-frequency vibration signals, determines the magnitude of the current to be applied to the actuator, and generates a current control command to send to the actuator. The actuator executes the current control command to adjust the viscosity of the smart fluid. The central controller applies a current of a specific intensity to the electromagnetic coil in the smart fluid, causing the electromagnetic coil to generate a corresponding magnetic field, thereby increasing the shear modulus of the smart fluid and suppressing vibration and its radiated noise.

2. The intelligent active vibration reduction and noise reduction interior panel for a suborbital space tourism spacecraft according to claim 1, characterized in that: The vibration sensing network includes accelerometers or fiber optic strain sensors distributed on the cabin structure and interior panels.

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