Flexible solar wing unfolding mechanism based on shape memory material and folding and unfolding method

Abstract

The invention relates to a flexible solar wing unfolding mechanism based on a shape memory material, which belongs to the technical field of aerospace engineering and comprises a mounting bracket, a substrate group, a shape memory pin puller, a winding drum, a shape memory extension arm, a connecting rod and a shape memory tensioning assembly, the shape memory pin puller is used for locking the base plate group in a folded state; one end of the shape memory stretching arm is connected with the winding drum, the other end of the shape memory stretching arm is connected with the connecting rod, and the shape memory stretching arm can generate shape recovery under excitation and drive the connecting rod to move so as to drive the substrate group to unfold; the shape memory tensioning assembly is arranged between the rigid base plate and the connecting rod and exerts tensioning force on the base plate set after the base plate set is unfolded so as to improve the structural rigidity in the unfolded state, the design of the unfolding mechanism can effectively improve the storage ratio of the unfolding mechanism, the satellite loading launching requirement of a stacked satellite is met, and the unfolding mechanism is suitable for being popularized and applied. And after being unfolded, the structure has the characteristics of adjustable tensile force and relatively high unfolding fundamental frequency.

Description

Technical Field

[0001] This invention belongs to the field of aerospace engineering technology, specifically relating to a flexible solar array deployment mechanism and deployment / retraction method based on shape memory materials. Background Technology

[0002] With the rapid development of aerospace technology, spacecraft are evolving towards miniaturization, lightweighting, and low cost, and flat-panel (stacked) satellites have become one of the important application forms. As the main power source for satellites, the solar panels' storage ratio, deployment reliability, and post-deployment stiffness directly affect the overall performance of the satellite.

[0003] Compared to traditional rigid and semi-rigid solar arrays, flexible solar arrays offer significant advantages such as lighter weight, higher power-to-weight ratio, and greater compactness, making them a crucial trend for future development. Currently, common flexible solar array compaction methods fall into two categories: roll-up and folding. Roll-up solar arrays have limited compactness due to the constraints of the bending radius of the solar cells and internal circuitry. Folding solar arrays, on the other hand, maintain a planar state throughout the folding and unfolding process, minimizing bending requirements on the solar cells and circuitry. They are directly compatible with mature and inexpensive rigid solar cells and are more suitable for the mounting layout of flat-panel satellites.

[0004] The main driving methods for flexible solar arrays include motor-driven and elastic deployment. While motor-driven deployment offers controllable deployment, it involves complex mechanisms and a relatively large mass. Elastic deployment, on the other hand, while structurally simple, suffers from significant deployment impact and is difficult to control during the deployment process. Furthermore, after deployment, the insufficient stiffness of the membrane surface results in a low fundamental frequency, which can easily lead to attitude control problems for spacecraft. Therefore, applying appropriate tension to the flexible substrate after deployment to increase the fundamental frequency is a critical engineering challenge that urgently needs to be addressed.

[0005] Current methods for monitoring the deployment process of flexible solar panels primarily rely on contact sensors or single-band optical measurements. Contact sensors impose additional loads on the flexible components, have sparse measurement points, and struggle to acquire full-field deformation information. Single-band optical measurements are prone to echo loss or signal saturation when there are differences in reflectivity, incident angle variations, or wrinkles in different regions of the flexible substrate, and they are difficult to reliably acquire continuous measurement data during dynamic deployment. Multi-beam or multi-camera non-coaxial measurement schemes often require complex registration due to parallax and extrinsic parameter drift, resulting in long error chains and making it difficult to meet the real-time and consistency requirements of the deployment process.

[0006] Therefore, there is an urgent need for a flexible solar array deployment mechanism and its deployment and retraction method that is simple in structure, lightweight, has a high storage ratio, controllable deployment process, high fundamental frequency after deployment, and is easy to detect during the process. Summary of the Invention

[0007] The purpose of this invention is to overcome the problems of limited retraction ratio, insufficient deployment stiffness, large deployment impact, and insufficient accuracy of deployment process state detection in the existing technology of flexible solar wings. It provides a flexible solar wing deployment mechanism and its retraction and deployment method based on shape memory materials, which can achieve high retraction ratio folding and retraction, low impact active drive deployment, adjustable tension after deployment, significantly improved deployment fundamental frequency, and compatibility with rigid solar cells and flat-panel satellite configuration requirements.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: On one hand, this invention provides a flexible solar array deployment mechanism based on shape memory materials, including a rigid substrate, a flexible substrate, a shape memory puller, a shape memory extension arm, a shape memory tensioning assembly, a roll, a mounting bracket, and a connecting rod; the rigid substrate consists of two pieces, located at both ends of the substrate group (the first and last pieces counted along the mounting bracket direction); the flexible substrate is located between the two rigid substrates, and its quantity can be customized according to mission requirements; increasing the quantity will correspondingly increase the specific power-to-mass or specific power-to-volume ratio; the shape memory puller is used to lock the solar array mechanism in a folded and retracted state during satellite launch, and its locking layer is made of shape memory polymer composite material; the shape memory puller... The shape memory extension arm is made of shape memory polymer composite material and is wound up. Under the shape memory effect of the material, it actively recovers its elongation to drive the deployment of the solar wing. The shape memory tensioning component is made of shape memory polymer composite material using 4D printing technology and is installed between the rigid substrate and the connecting rod. After the shape memory extension arm is fully deployed, it applies tension to the substrate through shape memory recovery contraction. After the excitation is released, its stiffness can be increased by about two orders of magnitude, thereby significantly improving the fundamental frequency of the flexible solar wing deployment. The flexible solar wing includes two shape memory extension arms. One end of each shape memory extension arm is fixedly connected to the roll and the other end is connected to the connecting rod. The roll is fixedly connected to the mounting bracket.

[0009] Preferably, the rigid substrate is filled with a metamaterial structure, which has the function of energy absorption and vibration reduction; the flexible substrate is made of polyimide film, which has the characteristics of high strength and light weight.

[0010] Preferably, the shape memory puller, shape memory extension arm, and shape memory tensioning assembly are all made of shape memory polymer composite material. The shape memory polymer composite material includes a matrix phase and a reinforcing phase: the matrix phase is selected from epoxy, cyanate ester, and polyaryletherketone shape memory polymers; the reinforcing phase is selected from particles, chopped fibers, and continuous fibers.

[0011] Preferably, the glass transition temperature range of the matrix phase is: 80–180°C when using epoxy-based shape memory polymers; 180–200°C when using cyanate-based shape memory polymers; and 130–200°C when using polyaryletherketone-based shape memory polymers.

[0012] Preferably, the locking plate layer of the shape memory puller and the shape memory extension arm are fixedly provided with temperature-adjustable electrothermal elements for applying thermal excitation to the shape memory material to trigger its shape memory effect.

[0013] Preferably, the cross-sectional shape of the shape memory extendable arm can be designed as a thin-shell structure such as C-shape, pod shape, herringbone shape or N-shape, depending on the storage ratio and unfolding stiffness requirements.

[0014] Preferably, the shape memory extension arm can be made entirely of shape memory polymer composite material; or it can be composed of a composite structure with conventional carbon fiber reinforced prepreg composite material as the matrix and a shape memory functional layer attached to its surface, so as to reduce the energy input required for driving the deployment.

[0015] Preferably, the shape memory tensioning component is fabricated using 4D printing technology with a conductive particle-reinforced shape memory polymer composite material. Its internal structure is filled with metamaterials, enabling it to achieve a constant tension force output within a certain elongation range and exhibiting excellent energy absorption and vibration damping performance, effectively absorbing the vibration and impact energy during rocket launch. The tension force can be adjusted by regulating the internal microstructure of a single tensioning component or changing the number of basic units.

[0016] Preferably, the flexible solar array deployment mechanism further includes a multi-wavelength coaxial laser scanning system for non-contact detection of the geometric state of the substrate assembly during deployment. The laser scanning system includes a multi-wavelength laser emitting unit, a beam-combining optical assembly, a scanning assembly, and a signal receiving and processing assembly. Different wavelength lasers are coaxially combined by the beam-combining optical assembly to form a composite beam, which is then driven by the scanning assembly to scan and measure the substrate assembly during deployment. Since different wavelength lasers share the same emission optical axis and scanning path, echo data from each band can be processed under a unified coordinate reference, thereby reducing registration errors caused by the non-coaxial arrangement of multiple sensors. The signal receiving and processing assembly can dynamically select or fuse the main band based on the quality of the echo signals from each band to improve the continuity and stability of geometric state detection during deployment.

[0017] On the other hand, the present invention provides a method for deploying and retracting a flexible solar wing deployment mechanism based on shape memory material, which is implemented using the aforementioned flexible solar wing deployment mechanism and includes a deployment process and a retraction process.

[0018] The unfolding process includes the following steps: Step 1: Initial state: The solar panels are folded and pressed against the satellite module, and the shape memory pins are locked. Step 2: Unlocking the shape memory pin puller: The locking plate of the shape memory pin puller is heated by electricity. Driven by the shape memory effect, the plate actively returns from a flat locking state to an Ω shape, causing the locking pin to retract, releasing the constraint on the locking ring, thereby unlocking the solar panel; disconnect the heating of the locking plate. Step 3: The shape memory extension arm unfolds and drives the substrate to unfold: The shape memory extension arm is heated by electricity. Under the action of the material shape memory effect, the extension arm rotates around the drum, pushing the connecting rod to move linearly along the extension direction. The rigid substrate and the flexible substrate unfold in sequence until they are coplanar with the mounting bracket; the heating of the shape memory extension arm is turned off. Step 4: Tensioning the substrate with the shape memory tensioning component: The shape memory tensioning component is heated by electricity to bring it to a softened state above the glass transition temperature. Under the force of the shape memory extension arm, it is stretched and generates a restoring force, applying a tensioning preload to the substrate. After the heating is turned off, the modulus of the shape memory material increases as the temperature decreases, the stiffness of the component is greatly improved, and the fundamental frequency of the solar array system deployment is significantly increased. The solar array deployment is complete.

[0019] The gathering process includes the following steps: Step 1: Initial state: The solar panels are fully deployed; Step 2: Apply pre-deformation to the shape memory tensioning component: Heat the shape memory tensioning component to above its glass transition temperature, apply tension to stretch it to the preset length, maintain the tension and turn off the power, and remove the tension after cooling to room temperature. The tensioning component is then fixed in the stretched deformation state. Step 3: Shape memory extension arm winding and folding substrate: The shape memory extension arm is heated to above its glass transition temperature. The drum is rotated to wind and fold the extension arm, while the rigid and flexible substrates are folded and stacked in a Z-shape. The torque is maintained and the power is turned off. After cooling to room temperature, the torque is removed and the extension arm remains in the winding state. Step 4: Shape Memory Pin Locking: Make the clamping assembly fit tightly against the folded rigid substrate, and use a rope to align the locking ring with the locking pin coaxially through the pulley; heat the shape memory locking sheet to above the glass transition temperature, apply pressure to the upper surface of the Ω-shaped sheet to flatten it, maintain the pressure and turn off the power, and release the pressure after cooling to room temperature. The locking sheet remains flat, and the locking pin passes through the locking ring to lock the solar panel; the solar panel retraction is complete.

[0020] Compared with the prior art, the beneficial effects of the present invention are reflected in the following aspects: 1. Simple structure, light weight, and high reliability. Utilizing shape memory polymer composite materials as the active drive element eliminates the need for complex motor drive mechanisms, significantly reducing the weight and complexity of the mechanism while improving on-orbit deployment reliability.

[0021] 2. The deployment process is controllable and has low impact. The shape recovery rate of the shape memory material can be adjusted by heating power. Compared with elastic deployment, the deployment impact load is significantly reduced, which helps protect on-board equipment.

[0022] 3. High compactness, suitable for stacked satellites. The substrate is folded in a Z-shape, and the shape memory extension arm is rolled up, resulting in a high overall compactness that fully meets the satellite mounting layout requirements of stacked flat-panel satellites.

[0023] 4. High fundamental frequency and adjustable tension. After the shape memory tensioning component is fully deployed and powered off, its stiffness increases by approximately two orders of magnitude, significantly improving the fundamental frequency of the flexible solar array system's deployment. The tension can be flexibly adjusted by regulating the number of microstructures or basic units.

[0024] 5. Compatible with rigid solar cells, low cost. The substrate remains flat throughout the entire process of folding and unfolding, allowing the direct use of mature and inexpensive rigid solar cells, thus reducing overall costs.

[0025] 6. High scalability. The power generation capacity can be increased by increasing the number of flexible substrates and the length of the extension arms, without a significant increase in the overall mass of the mechanism. The specific power-to-mass ratio and specific power-to-volume ratio can be greatly improved, making it suitable for tasks with different power requirements.

[0026] 7. Strong deployment process detection capability. Employing a multi-wavelength coaxial laser scanning system, it can perform non-contact geometric state detection during the solar array deployment process. Since different laser bands share the same output optical axis and scanning path, the complexity of multi-source measurement data registration is reduced. When a single band is affected by differences in substrate surface reflection characteristics, changes in incident angle, or local wrinkles, other bands can still provide supplementary information, thereby helping to improve the continuity and consistency of measurement data during the dynamic deployment phase.

[0027] The technical solution of the present invention will be further described in detail below through embodiments. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the flexible solar array deployment mechanism based on shape memory material provided in an embodiment of the present invention in a folded and retracted state. Figure 2 This is a schematic diagram of the flexible solar array deployment mechanism based on shape memory material provided in an embodiment of the present invention in its fully deployed state. Figure 3This is a schematic diagram of the shape memory pin puller in the locked state according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the shape memory pin puller in the unlocked and released state according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the C-shaped cross-section of the shape memory extender arm provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the pod-shaped cross-section of the shape memory extender arm provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the herringbone cross-section of the shape memory extender arm provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of the N-shaped cross-section of the shape memory extender arm provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the C-shaped cross-section shape memory extension arm composite structure (shape memory functional layer + carbon fiber reinforced prepreg base layer) provided in an embodiment of the present invention; Figure 10 This is a schematic diagram of the shape memory tensioning component structure provided in an embodiment of the present invention; Figure label: 1. Rigid substrate; 2. Flexible substrate; 3. Shape memory pin puller; 4. Shape memory extension arm; 5. Shape memory tensioning assembly; 6. Roller; 7. Mounting bracket; 8. Linkage rod.

[0029] 3-1. Shape memory locking plate; 3-2. Locking pin; 3-3. Locking ring; 3-4. Pulley; 3-5. Pressing assembly.

[0030] 4-1. Shape memory functional layer; 4-2. Conventional carbon fiber reinforced prepreg composite material. Detailed Implementation

[0031] To enable those skilled in the art to better understand the present application, the technical solutions in specific embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by those skilled in the art.

[0032] The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects.

[0033] Example 1 like Figure 1 and Figure 2 As shown, the flexible solar wing deployment mechanism based on shape memory material provided by the present invention includes a rigid substrate 1, a flexible substrate 2, a shape memory puller 3, a shape memory extension arm 4, a shape memory tensioning assembly 5, a roll 6, a mounting bracket 7, and a connecting rod 8.

[0034] The unfolding mechanism has two working states: folded and fully unfolded. In the folded state, the rigid substrates 1 and flexible substrates 2 are stacked in a Z-shaped folding manner, the shape memory extension arm 4 is wound onto the roll 6, the internal locking plate of the shape memory puller 3 is in a flat (extended) locking state, and is fixed by the locking pin 3-2 passing through the locking ring 3-3. The pressing component 3-5 is pressed tightly on the surface of the folded substrate, so that the solar array as a whole is kept in a pressed and folded state.

[0035] After the satellite is launched into orbit, electrothermal excitation is applied to the shape memory puller 3, shape memory extension arm 4, and shape memory tensioning assembly 5 in sequence. By utilizing the shape recovery effect of the shape memory material, the solar array can be autonomously unlocked, deployed, and tensioned.

[0036] The substrate assembly consists of two rigid substrates 1 (internally filled with metamaterials) at both ends and several flexible substrates 2 (polyimide films) in the middle. The rigid substrates 1 maintain a planar state throughout the entire process of folding and unfolding, and are directly compatible with rigid solar cells, reducing the cost of cell selection. The number of flexible substrates 2 can be flexibly customized according to the power generation required for the task.

[0037] like Figure 3 and Figure 4 As shown, the shape memory pin puller 3 includes a shape memory locking plate layer 3-1, a locking pin 3-2, a locking ring 3-3, a pulley 3-4, and a pressing assembly 3-5.

[0038] Locked state ( Figure 3 The shape memory polymer composite sheet 3-1 is in a flat and elongated state (pre-deformed state). The locking pin 3-2 on the puller passes through the locking ring 3-3. The locking ring 3-3 is connected to the pressing assembly 3-5 by a rope passing around the pulley 3-4. The pressing assembly 3-5 is pressed tightly against the surface of the folded rigid substrate 1 to achieve reliable locking of the solar array and prevent accidental deployment in the vibration environment of rocket launch.

[0039] Unlocked status ( Figure 4 When the shape memory locking layer 3-1 is heated to above its glass transition temperature, the layer actively recovers from its flat state to its initial Ω shape under the drive of the shape memory effect, which causes the locking pin 3-2 to retract and disengage from the locking ring 3-3, thereby releasing the constraint on the clamping component 3-5, releasing the lock on the substrate, and allowing the solar panel to deploy.

[0040] The shape memory locking layer 3-1 is made of shape memory polymer composite material. The matrix phase can be epoxy (glass transition temperature Tg = 80–180℃), cyanate ester (Tg = 180–200℃), or polyaryletherketone (Tg = 130–200℃) shape memory polymers. The reinforcing phase can be granular, chopped, or continuous fibers to meet different requirements for stiffness, recovery force, and adaptability to on-orbit thermal environments. Temperature-adjustable electrothermal elements are fixedly installed on the layer to precisely control the timing and rate of shape recovery.

[0041] The shape memory extender arm 4 is a thin-shell structure made of shape memory polymer composite material. It is wound onto the roll 6 and automatically unfolded by the shape memory recovery of the material.

[0042] like Figures 5 to 8 As shown, the cross-sectional shape of the shape memory extender 4 can be selected according to the specific requirements of the task regarding the storage ratio and deployment stiffness, including C-shape ( Figure 5 ), pod-shaped ( Figure 6 ), herringbone shape ( Figure 7 ) and N-shaped ( Figure 8 Thin shell cross-sections, etc.

[0043] like Figure 9 As shown, the shape memory extender arm 4 can also adopt a composite structure: using a conventional carbon fiber reinforced prepreg composite material 4-2 as the matrix structure layer, and attaching a shape memory functional layer 4-1 with a shorter arc length to its surface. The driving torque generated by the shape memory functional layer 4-1 after excitation drives the entire extender arm to unfold along the drum. This implementation scheme can significantly reduce the energy consumption required to drive shape memory recovery while retaining the shape memory driving characteristics.

[0044] One end of each shape memory extension arm 4 is fixedly connected to the drum 6, and the other end is connected to the connecting rod 8. When powered on for heating, the extension arm rotates around the drum 6, pushing the connecting rod 8 to move linearly along the unfolding direction, sequentially unfolding the rigid substrate 1 and the flexible substrate 2 from a Z-shaped folded state to a coplanar position. After unfolding, the unfolded length of the solar panel is greater than the total length of the substrate assembly, ensuring that the substrate is completely stretched and flattened.

[0045] Both the shape memory extension arm 4 and the shape memory locking plate layer 3-1 are equipped with temperature-adjustable electrothermal elements to precisely control the excitation temperature and heating rate, ensuring the consistency and reliability of the shape memory recovery process.

[0046] like Figure 10 As shown, the shape memory tensioning component 5 is installed between the rigid substrate 1 and the connecting rod 8. It is made of a shape memory polymer composite material reinforced with conductive particles using 4D printing technology and is filled with a metamaterial structure.

[0047] The complex microstructure within the metamaterial enables the tensioning component 5 to achieve a nearly constant tensile force output within a certain displacement and stretching range, avoiding problems such as uneven distribution of tension force on the substrate or torsional deformation caused by differences in deformation between basic units. The magnitude of the tension force can be flexibly adjusted by adjusting the internal microstructure parameters of a single tensioning component 5 or changing the number of basic units to adapt to the tensioning requirements of solar arrays of different sizes.

[0048] At the end of the shape memory extension arm 4's deployment, the shape memory tensioning component 5 is heated by electricity, causing its modulus to decrease rapidly (entering the glass transition state). Under the force of the extension arm, the tensioning component 5 is moderately stretched and generates a shape recovery force, applying a tension preload to the flexible substrate 2. Since the material is in a high-temperature softened state at this time, the stress is small and will not cause damage to the flexible substrate 2.

[0049] After the shape memory extension arm 4 is fully deployed, the excitation to the shape memory tensioning component 5 is disconnected. Its modulus increases significantly as the temperature decreases (by about two orders of magnitude), the overall stiffness of the component increases significantly, and the fundamental frequency of the flexible solar array system increases significantly, effectively solving the problem of insufficient stiffness after deployment of traditional flexible solar arrays.

[0050] In addition, the metamaterial structure inside the shape memory tensioning component 5 has excellent energy absorption and vibration reduction characteristics, which can effectively dissipate the vibration and impact energy during the rocket launch phase and protect the integrity of the solar array structure.

[0051] Example 2 In this embodiment, the flexible solar array deployment mechanism is also equipped with a blue-green-red three-beam coaxial laser scanning system (LBS) for non-contact real-time detection of the geometric state during the deployment process.

[0052] The LBS system includes a blue light emitting unit, a green light emitting unit, a red light emitting unit, a beam combining optical assembly (dichroic mirror group), a scanning assembly, and a signal receiving and processing assembly. Three laser beams of different wavelengths are coaxially combined using dichroic optical elements. The combined beam shares the same scanning actuator and is projected onto the substrate surface during the deployment process to acquire geometric information such as the solar array deployment angle, end displacement, and out-of-plane deflection.

[0053] Since the three beams share the same optical axis and scanning angle, the obtained echo data of different bands are naturally in the same spatial coordinate system. Multi-band data fusion can be achieved without complex external parameter calibration, reducing multi-source data registration errors and improving the consistency of geometric reconstruction during the unfolding process.

[0054] In another embodiment, the signal processing component performs weighted fusion or dynamic selection of the main band based on the intensity, signal-to-noise ratio, or saturation level of the echo signals in each band. When a certain band experiences weak echoes, saturation, or abnormal scattering due to differences in the reflectivity of the flexible substrate surface, specular reflection, or wrinkles, other bands can still maintain effective measurements, thereby reducing the missed detection rate and improving the continuity and stability of measurement data during the dynamic deployment phase. Coaxial projection of the three beams also ensures that the three bands operate under the same shading / shadowing conditions, avoiding inconsistencies in visibility between bands caused by different emission directions, and facilitating the consistent identification of abnormal echoes.

[0055] Example 3 This embodiment illustrates the deployment process, using a stacked flat-panel satellite as an example. Initially, the solar panels are folded and retracted, pressed firmly against the satellite's surface. After the satellite enters orbit, the solar panels are deployed according to the following steps: Step 1 (Unlocking): A ground-based command is injected to energize and heat the locking layer 3-1 of the shape memory pin puller 3 (heating power is selected based on the layer material's Tg, typically set to Tg+20℃). Within approximately 30–60 seconds, the locking layer 3-1 returns from a flat state to its initial Ω-shape, causing the locking pin 3-2 to retract and disengage from the locking ring 3-3, thus releasing the solar panel from its lock. Heating is then discontinued.

[0056] Step 2 (Deployment): The two shape memory extension arms 4 are simultaneously energized and heated. Within approximately 3–10 minutes, the extension arms smoothly retract around the roll 6, pushing the connecting rod 8 to move along the deployment direction. The rigid substrate 1 and flexible substrate 2 sequentially deploy to their coplanar positions. During deployment, the laser scanning system performs real-time or near-real-time detection of the solar array deployment angle, end displacement, and out-of-plane deflection for deployment status monitoring and anomaly detection. Heating is disconnected after deployment is complete.

[0057] Step 3 (Tensioning): The shape memory tensioning component 5 is energized and heated. After softening, it is moderately stretched under the force of the extension arm, simultaneously generating a shape recovery contraction force, applying a uniform tension force to the flexible substrate 2. After power is turned off, the stiffness of the tensioning component 5 increases by approximately two orders of magnitude, and the fundamental frequency of the overall solar array deployment is significantly improved. The solar array deployment is complete, and it enters normal on-orbit operation.

[0058] Example 4 This embodiment is a folding process embodiment, with ground testing or on-orbit reconfiguration scenarios as the background: Step 1 (Pre-deformation of tensioning component): Heat the shape memory tensioning component 5 to above Tg, apply tension to stretch it to the preset length, maintain the tension and turn off the power, cool it to room temperature and then remove the tension. The tensioning component 5 remains in a stretched and deformed state.

[0059] Step 2 (Extending Arm Winding and Folding Substrate): Heat the shape memory extending arm 4 to above Tg, rotate the roller 6 to rewind and reassemble the extending arm, simultaneously causing the substrate to fold and stack in a Z-shape. Maintain torque and disconnect power, cool to room temperature, and then remove the torque, keeping the extending arm in a wound state.

[0060] Step 3 (Pin Locking): Position the clamping assembly 3-5 against the surface of the folded substrate. Align the locking ring 3-3 with the locking pin 3-2 via a rope passing over the pulley 3-4. Heat the shape memory locking layer 3-1 to above Tg. Apply pressure to the upper surface of the Ω-shaped layer to flatten it. Maintain pressure and disconnect the power. After cooling to room temperature, remove the pressure. The locking layer 3-1 will remain fixed and flat. The locking pin 3-2 will pass through the locking ring 3-3 to complete the locking. The solar panel retraction is complete.

[0061] This invention enables the active-driven deployment of flexible solar panels. Compared with motor-driven solutions, it has a simpler structure, lighter weight, and higher reliability; compared with elastic deployment solutions, the deployment process is controllable and the deployment impact is small; compared with the roll-up solution, it is compatible with rigid solar cells, has lower cost, and meets the requirements for flat-panel satellite mounting, thus having broad engineering application prospects.

[0062] Finally, it should be noted that the described embodiments are merely some, not all, of the embodiments of the present invention. Those skilled in the art will understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents; that is, all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A flexible solar array deployment mechanism based on shape memory material, characterized in that, Includes mounting brackets, base plate assemblies, shape memory pin pullers, reels, shape memory extension arms, connecting rods, and shape memory tensioning components; The substrate assembly includes rigid substrates located at both ends and at least one flexible substrate disposed between the rigid substrates; The shape memory pin is used to lock the substrate assembly in a folded or retracted state; One end of the shape memory extension arm is connected to the drum, and the other end is connected to the connecting rod. The shape memory extension arm can recover its shape under excitation and drive the connecting rod to move, thereby driving the substrate assembly to unfold. The shape memory tensioning component is disposed between the rigid substrate and the connecting rod, and applies tension force to the substrate assembly after the substrate assembly is unfolded, so as to improve the structural rigidity in the unfolded state.

2. The flexible solar array deployment mechanism according to claim 1, characterized in that, At least one of the shape memory puller, the shape memory extension arm, and the shape memory tensioning assembly is made of shape memory polymer composite material and is equipped with an electrothermal excitation unit for triggering shape memory recovery.

3. The flexible solar array deployment mechanism according to claim 2, characterized in that, The shape memory polymer composite material includes a matrix phase and a reinforcing phase. The matrix phase is selected from one of epoxy, cyanate ester and polyaryletherketone, and the reinforcing phase is selected from one of particles, chopped fibers and continuous fibers.

4. The flexible solar array deployment mechanism according to claim 3, characterized in that, When the matrix phase is an epoxy-based shape memory polymer, the glass transition temperature range is 80~180℃; when the matrix phase is a cyanate-based shape memory polymer, the glass transition temperature range is 180~200℃; and when the matrix phase is a polyaryletherketone-based shape memory polymer, the glass transition temperature range is 130~200℃.

5. The flexible solar array deployment mechanism according to claim 1, characterized in that, The shape memory pin puller includes a locking plate layer, a locking pin, and a locking ring. Under excitation, the locking plate layer recovers its shape and drives the locking pin to retract relative to the locking ring, thereby releasing the lock.

6. The flexible solar array deployment mechanism according to claim 1, characterized in that, The shape memory extender arm is a thin-shell structure, or a composite structure consisting of a structural layer and a shape memory functional layer.

7. The flexible solar array deployment mechanism according to claim 6, characterized in that, The cross-sectional shape of the shape memory extender can be C-shaped, pod-shaped, herringbone-shaped, or N-shaped, depending on the storage ratio and unfolding stiffness.

8. The flexible solar array deployment mechanism according to claim 1, characterized in that, The shape memory tensioning component is made of a shape memory polymer composite material reinforced with conductive particles using 4D printing technology, and it outputs a constant tension force within a preset stretching range.

9. The flexible solar array deployment mechanism according to claim 1, characterized in that, It also includes a laser scanning system for non-contact detection of the substrate assembly unfolding process; the laser scanning system includes a multi-wavelength laser emitting unit, a beam combining optical component, a scanning component, and a signal receiving and processing component; the multi-wavelength laser emitting unit includes at least two different wavelength laser emitting sources, preferably including blue, green, and red laser emitting sources; the beam combining optical component is used to coaxially combine lasers of different wavelengths, so that each band of lasers shares the same output optical axis; the scanning component is used to drive the combined beam to scan the substrate assembly during the unfolding process; the signal receiving and processing component is used to receive echo signals of each band, and perform main band selection or weighted fusion according to signal strength, signal-to-noise ratio, or saturation state to obtain the geometric state information of the substrate assembly during the unfolding process.

10. A method for deploying and retracting a flexible solar array based on shape memory materials, characterized in that, The unfolding mechanism according to any one of claims 1-8 comprises: The shape memory puller is activated to release the lock on the substrate assembly; The shape memory extension arm is stimulated to return from a retracted state to an extended state and drive the base plate assembly to extend via a connecting rod. The shape memory tensioning component is excited to apply tension to the substrate assembly at the end of the unfolding process, and the structural stiffness in the unfolded state is improved after the excitation is stopped. During the retraction process, the shape memory tensioning component is pre-deformed, the shape memory extension arm is wound and retracted, and the shape memory puller is re-locked to the substrate assembly.

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