A multi-polymer synergic thermal control deformation structure and control method

Abstract

The application discloses a kind of multi-polymer synergic heat control deformation structures and control methods, including upper end connecting plate, at least three SMA springs, SMP cylinder, lower end connecting plate, and SMP cylinder is formed by a plurality of fluctuation lattice units arranged periodically;SMP cylinder inner surface is provided with flexible PI heating film, and SMP cylinder forms heat control air channel inside, and cooling fan is arranged in heat control air channel, and SMP cylinder inner surface is provided with infrared thermal array sensor;It also includes upper controller, lower controller, PWM temperature control module and SMA drive module;Instruction analysis module and K-means multi-target heat sensing module are configured in upper controller.The application adopts SMA spring and SMP fluctuation lattice cylinder composite structure, combines K-means multi-target heat sensing temperature measurement and five-stage working condition linkage control, has multidirectional active drive and temperature control stiffness lock shape ability, can realize arbitrary bending position continuous step deformation and rapid lock shape, temperature control precision is high, repeat consistency is good, and cyclic use is reliable.

Description

Technical Field

[0001] This invention relates to the field of multi-polymer synergistic thermal control deformation technology, specifically to a multi-polymer synergistic thermal control deformation structure and control method. Background Technology

[0002] With the rapid development of soft robots, bionic robots, and reconfigurable actuators, relying solely on the deformation of flexible materials is no longer sufficient to simultaneously meet the requirements of compliant contact and load-bearing capacity. It also fails to satisfy the comprehensive requirements of attitude controllability, repeatability, and stability against external loads. Therefore, there is an urgent need for variable stiffness deformation structures that can switch between compliant deformation and rigid load-bearing. Variable stiffness structures are key actuators for soft robots to achieve environmental adaptation, attitude maintenance, and precise operation. They can adapt to unstructured environments through continuous bending, torsion, or extension, and have high application value in scenarios such as precision gripping, complex surface fitting, confined space exploration, and medical interventional devices. Constructing structures with both active deformation and stiffness adjustment capabilities using smart materials such as shape memory alloys (SMA) and shape memory polymers (SMP) has become a core technological direction in the design of current soft robot actuators.

[0003] However, the thermal response deformation structure of existing soft robot actuators still has the following shortcomings: 1. Existing thermal response deformation structures generally use single-point contact temperature measurement or overall average temperature measurement, which cannot distinguish different temperature fields such as the heating source area, polymer matrix area, heat dissipation area and environmental background area. Affected by factors such as cylinder thickness gradient, local overheating and environmental thermal radiation, the temperature data is seriously distorted, making it difficult to accurately determine the true softening and cooling state of SMP. Problems such as overmelting failure, insufficient softening or unreliable locking are prone to occur, which directly affect the deformation control accuracy and structural operation safety.

[0004] 2. Existing variable stiffness soft structures mostly use discrete joints or localized phase change materials, lacking a continuous load-bearing skeleton that runs through the axis. This results in poor structural stability under long-stroke bending and torsional conditions. At the same time, they lack built-in heat dissipation channels and rely on natural cooling or external heating to achieve stiffness switching. This leads to slow heating and cooling rates and long locking times. It is difficult to balance structural load-bearing capacity, deformation compliance, and thermal response efficiency, which cannot meet the requirements of continuous soft robots for high-frequency and rapid deformation locking.

[0005] 3. Existing shape memory composite actuators mostly adopt simple switching quantities or single threshold open-loop control, without establishing a multi-condition hierarchical control mechanism. They cannot continue to program deformation from any locked posture, nor can they pause locking and continue bending at any position within the bending stroke. At the same time, the SMP temperature control and SMA drive lack timing linkage, which poses a risk of forcibly driving the SMA before the SMP has softened sufficiently, which can easily cause overload damage. Furthermore, each step of the drive does not use the actual softening state as a criterion, resulting in large deviations in repeated bending angles and poor deformation consistency. Summary of the Invention

[0006] To address the aforementioned shortcomings of existing technologies, this invention provides a multi-polymer collaborative thermal control deformation structure and control method. By using K-means multi-target thermal sensing temperature measurement, it solves the problems of inaccurate SMP temperature field identification and softening lock-shaped judgment deviation. By using the integrated design of the wave lattice hollow cylinder, it solves the problems of weak load-bearing capacity, poor heat dissipation, and slow heating and cooling rates. By using a five-level working condition linkage interlocking control architecture, it solves the problems of inability to arbitrarily lock-shaped continuous bending and poor consistency of asynchronous driving.

[0007] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows: A multi-polymer synergistic thermally controlled deformable structure includes an upper connecting plate, at least three SMA springs, an SMP cylinder, and a lower connecting plate. The upper and lower connecting plates are fixed parallel to each other on both sides of the SMP cylinder, with the axis of the SMP cylinder perpendicular to the upper connecting plate. Each SMA spring is fixedly connected to both sides of the upper and lower connecting plates, and the SMA springs are evenly distributed around the outer circumference of the SMP cylinder between the upper and lower connecting plates. When the SMA springs are in their normal state, the axes of the SMA springs are parallel to the axis of the SMP cylinder. The SMP cylinder is composed of a number of periodically arranged wave lattice units, each consisting of periodically undulating wave-shaped lattice walls. The peaks and troughs of adjacent lattice units are connected. The wave lattice units are continuously arranged along the circumferential and axial directions and interconnected to form a hollow cylindrical lattice structure. A flexible PI heating film is provided on the inner surface of the SMP cylinder, and a thermal control air channel is formed inside the SMP cylinder. A cooling fan is installed at one end, and an infrared thermal array sensor is installed on the inner surface of the SMP cylinder. The infrared thermal array sensor is used to collect two-dimensional temperature matrix data of the deformable structure surface in real time. It also includes an upper controller, a lower controller, a PWM temperature control module, and an SMA drive module. The cooling fan is electrically connected to the lower controller. The PWM temperature control module is electrically connected to the flexible PI heating film. The SMA drive module is electrically connected to the SMA spring. The upper controller is communicatively connected to the lower controller and the infrared thermal array sensor. The upper controller is equipped with an instruction parsing module and a K-means multi-target thermal sensing module. The instruction parsing module is used to receive user interaction actions. The upper controller is also equipped with a temperature interpolation module, which is used to interpolate the two-dimensional temperature matrix data collected by the infrared thermal array sensor to obtain an interpolated temperature matrix. The K-means multi-target thermal sensing module is used to perform unsupervised partitioning of the interpolated temperature matrix and identify the SMP target hot zone from the temperature image and calculate the target temperature.

[0008] Furthermore, the K-means multi-target thermal sensing module is configured to perform the following operations: perform unsupervised clustering on the temperature matrix acquired by the infrared thermal array sensor and after interpolation, divide the temperature image into three types of regions: SMP matrix thermal region, SMA high-temperature thermal region and environmental background region, identify the SMP target thermal region from them, and output the average temperature of the target thermal region as the target temperature.

[0009] Furthermore, the upper and lower connecting plates are provided with mounting limiting holes that mate with the SMP cylinder, and both ends of the SMP cylinder are fixedly connected to the mounting limiting holes.

[0010] Furthermore, both the upper and lower connecting plates are provided with spring mounting holes for installing SMA springs, and the two ends of the SMA springs are fixed in the spring mounting holes.

[0011] Furthermore, there are three SMA springs, which are arranged at 120° angles with respect to the central axis of the SMP cylinder.

[0012] A method for controlling the thermally deformable structure of multiple polymers, comprising the following steps: S11: After starting the upper controller and the lower controller, the upper controller first completes the initialization configuration of the infrared thermal array sensor, the K-means multi-target thermal sensing module and the instruction parsing module, and the lower controller simultaneously completes the initialization configuration of the PI heating film PWM drive channel, the cooling fan control channel and the SMA spring MOSFET drive channel. S12: By checking the data integrity and temperature range, the validity of the output of the infrared thermal array sensor is verified based on the criteria that the data matrix is ​​free of omissions and abnormal out-of-bounds values. If the verification result is valid, proceed to step S13; otherwise, directly enter the fault protection state. S13: Detects the working status of the upper controller communication link, lower controller communication link, PI heating film circuit, cooling fan circuit and SMA drive module, and determines whether to trigger emergency stop protection based on the detected working status results, and enters fault protection state when triggered. If at least one of the following is detected to be in an abnormal working state: the upper controller communication link, the lower controller communication link, the PI heating film circuit, the cooling fan circuit, or the SMA drive module, all outputs are immediately locked and the system enters a fault protection state; otherwise, a temperature monitoring and execution control closed loop is established, and the system enters the standby preheating mode of the next step S2. S2: SMP cylinder preheating stage; After preheating the SMP cylinder to a low-stiffness softened state from its initial posture, it enters the S3 step bending stage upon receiving the step bending command input by the user through the interactive interface; Specifically: S21: The host controller sequentially calls the infrared temperature matrix acquisition and interpolation method and the K-means multi-target thermal sensing model to identify the hot zone of the SMP cylindrical target and calculate the real-time temperature of the SMP target hot zone. S22: Call the viscoelastic temperature change equivalent model to determine the stiffness state of the SMP cylinder in real time. The stiffness state includes a high-stiffness glass state and a low-stiffness rubber state. S23: Based on the deviation between the real-time temperature of the SMP target hot zone and the preset preheating temperature threshold, the upper controller gradually heats up the SMP cylinder in the initial state through the PID closed-loop temperature control algorithm, and adjusts it through the PID closed-loop temperature control algorithm to keep the temperature of the SMP cylinder stable within the preheating range of low stiffness rubber state. S24: After the SMP cylinder reaches a low-stiffness rubber state, keep all SMA drive circuits de-energized and continue to wait for action commands. S25: When the upper controller receives the step bending command input by the user, it proceeds to step S3; when it receives the recovery reset command, it proceeds to step S5; when it receives an abnormal trigger, it enters the emergency stop protection state, that is, it proceeds to step S6. S3: Stepping Bending Phase; After completing the target number of steps or target posture in stepping bending, stop SMA driving and enter the S4 shaping and locking phase; Specifically: S31: After receiving the stepping bending command, the host controller uses the command parsing module to extract the features of the input command string, parses out the bending direction parameters, execution step parameters, and stepping type parameters involved in the drive, and re-calls the infrared temperature matrix acquisition and interpolation method and the K-means multi-objective thermal sensing model to obtain the current SMP cylinder temperature information. It then uses the viscoelastic temperature change equivalent model to determine whether the SMP cylinder has reached the low stiffness softening state. When the SMP cylinder is preheated to the low stiffness rubber state, the host controller releases the safety state that prohibits SMA power supply and allows current output; otherwise, it continues to return to step S2 to preheat the SMP cylinder until it reaches the low stiffness softening state. S32: The upper controller selects the corresponding SMA spring according to the bending direction parameters obtained from S31, and calculates the required driving pulse parameters using the SMA thermo-coupling constitutive model in combination with the execution step number parameters and step type parameters obtained from the analysis; then it instructs the lower controller to output the driving pulse through the SMA driving module, so that the target SMA spring heats up and contracts in a phase change, completing a single step action. S33: After a single stepping action is completed, the upper controller calls the infrared temperature matrix acquisition and interpolation method and the K-means multi-objective thermal sensing model to acquire temperature and identify hot zones, calls the viscoelastic temperature change equivalent model to determine the stiffness state of the SMP cylinder, and combines the SMA thermo-coupling constitutive model to evaluate the current bending attitude. If the evaluation result shows that the set number of execution steps or the target attitude has been reached, the stepping bending stage ends and automatically enters the next step S4. If the evaluation result shows that the set number of execution steps or the target attitude has not been reached, the controller returns to step S32, continues to calculate and output the next driving pulse to perform the stepping action until the target attitude is reached. S4: Forming and locking control stage; after cooling and locking, the structure maintains its current configuration for an extended period, while simultaneously returning to the command listening state, awaiting a secondary deformation or reset command; specifically: S41: When a forming command is received or the step bending reaches the target posture, the lower controller shuts down or reduces the output power of the PI heating film and starts the cooling fan to cool down the SMP cylinder. S42: During the cooling process, the infrared temperature matrix acquisition and interpolation method and the K-means multi-objective thermal sensing model are continuously called to detect the real-time temperature of the SMP target hot zone of the SMP cylinder in real time, and the stiffness state of the SMP cylinder is judged in real time by combining the viscoelastic temperature change equivalent model. S43: When the real-time temperature of the SMP target hot zone drops to the locking temperature threshold and this state is maintained for a preset time, it is determined that the SMP cylinder has recovered to the high-stiffness glass state, that is, the physical locking of the current bending posture is achieved by using the high-stiffness glass state itself. S44: After the current bending posture is locked, turn off the cooling fan and keep all SMA spring drives powered off, so that the SMP cylinder maintains the current bending posture. At the same time, the upper controller continues to listen and wait to receive user commands. When the next bending posture deformation command is received, return to step S3. When the recovery reset command is received, proceed to the next step S5. When the abnormal trigger command is received, proceed to step S6. S5: Reset Phase; Upon receiving a reset command, the system enters the S5 reset phase. After reset, it automatically returns to the S2 standby warm-up mode. Specifically: S51: When the upper controller receives the recovery reset command, it restarts the PI heating film to heat the SMP cylinder, and obtains the real-time temperature of the SMP target hot zone of the SMP cylinder in real time through the infrared temperature matrix acquisition and interpolation method and the K-means multi-objective thermal sensing model. Then, it uses the viscoelastic temperature change equivalent model to determine whether the SMP cylinder has returned to the low stiffness rubber state. S52: When the SMP cylinder reaches a low-stiffness rubber state, the SMP cylinder regains its deformation freedom. S53: After the SMP cylinder recovers its deformation degrees of freedom, it combines the SMA thermo-coupling constitutive model and utilizes the restoring force of the SMA spring after cooling and elongation to its original length. Combined with the shape memory recovery effect of the SMP cylinder itself, it drives the SMP cylinder to return to its initial posture. The SMP cylinder returns to its initial posture and enters the next step. S54: After the SMP cylinder returns to its initial position or when the upper controller receives an interactive command from the user confirming the completion of the reset, the drive power supply of the PI heating film and all SMA springs is turned off, and the process returns to step S2.

[0013] Furthermore, during the operation of steps S2 to S5, the control system synchronously executes emergency stop monitoring step S6, which specifically includes: S61: During the operation of steps S2 to S5, abnormal information is monitored in real time. Abnormal information includes electrical abnormalities of the PI heating film circuit, cooling fan circuit and SMA drive module defined in step S1, as well as temperature exceeding the limit in the temperature monitoring closed-loop feedback in steps S2-S5. S62: When abnormal information is detected, the control system immediately calls the infrared temperature matrix acquisition and interpolation method and the K-means multi-objective thermal sensing model to complete the thermal zone identification of the SMP main body thermal zone, the SMA local high temperature thermal zone and the background thermal zone, and combines the viscoelastic temperature change equivalent model and the SMA thermo-coupling constitutive model to determine whether the current temperature of the SMP cylinder and the SMA spring exceeds the safe working range preset in the upper controller. S63: If step S62 determines that the safe operating range is exceeded, then immediately cut off the power supply to all SMA drive circuits and PI heating film; if the temperature exceeds the safe temperature threshold preset by the upper controller, then start the cooling fan for forced heat dissipation, otherwise maintain the fan as before; if it is determined that the safe operating range is not exceeded, then maintain the current operating state of the system. S64: After the temperature recovers to the safe temperature range preset in the upper controller and the fault is eliminated, return to step S2; if the upper controller detects that the drive circuit current is continuously abnormal or the sensor data is missing, it is determined to be an unrecoverable hardware fault. The upper controller immediately triggers the fault lock state, cuts off all function outputs, and waits for manual reset after the hardware fault is eliminated.

[0014] Furthermore, the infrared temperature matrix acquisition and interpolation method specifically includes: M11: Reads the raw two-dimensional temperature matrix data collected by the infrared thermal array sensor. The raw resolution of the raw temperature matrix is ​​32×24. M12: The original temperature matrix is ​​upsampled and interpolated using a cubic interpolation algorithm to obtain an interpolated temperature matrix with improved resolution, which is then used for subsequent K-means hot zone identification.

[0015] Furthermore, the execution steps of the K-means multi-objective thermal sensing model include: M21: Set the number of clusters and initial cluster centers; using each temperature data point in the interpolated temperature matrix as a sample, set the number of clusters and initialize the cluster centers; M22: Calculate the distance between temperature data points and cluster centers; calculate the distance from each temperature data point to each cluster center separately; M23: Data point cluster allocation; each temperature data point is assigned to the cluster corresponding to the nearest cluster center, forming multiple temperature data point sets; M24: Update cluster centers; recalculate the average value of all temperature data points within each cluster and use this average value as the new cluster center for the corresponding cluster; M25: Iterative convergence judgment; Repeat steps M22 to M24 until the change in each cluster center meets the convergence condition, and the clustering is completed. M26: Target hot zone selection; Select the SMP main hot zone as the target hot zone from multiple hot zones obtained by clustering; M27: Target Temperature Calculation; Calculates the average temperature of all temperature data points within the SMP main thermal zone, and outputs the real-time temperature of the SMP target thermal zone.

[0016] Furthermore, the viscoelastic temperature-dependent equivalent model is used to determine the stiffness state of the SMP cylinder, specifically including the following steps: M31: Obtain the real-time temperature of the target hot zone of SMP at the current moment, establish the correspondence between the relaxation modulus of SMP material and time based on the superimposed generalized Maxwell viscoelastic model, and extract the SMP relaxation time parameter in the correspondence to characterize the viscoelastic properties of SMP. M32: Using the WLF temperature-time equivalence relationship, the SMP relaxation time at different temperatures is equivalently converted to obtain the influence law of temperature on the SMP relaxation response speed. M33: Using the glass transition temperature of SMP material as the judgment threshold, the real-time temperature of the target hot zone of SMP is compared with the glass transition temperature; when the real-time temperature of the target hot zone of SMP is lower than the glass transition temperature, the SMP cylinder is determined to be in a high-stiffness glass state, suitable for lock-holding; when the real-time temperature of the target hot zone of SMP is higher than or equal to the glass transition temperature, the SMP cylinder is determined to be in a low-stiffness rubber state, suitable for SMA spring-driven deformation or shape recovery.

[0017] Furthermore, the SMA thermo-coupled constitutive model is used for driving pulse parameter calculation and bending attitude assessment, specifically including the following steps: M41: Obtain the current state parameters of the SMA spring, including the current temperature, martensite volume fraction, and elastic strain; M42: Based on the isotropic thermomechanical constitutive framework, the total free energy density of the SMA spring is decomposed into three parts: elastic performance density, phase transition free energy density, and pure thermal free energy density, which are calculated separately. M43: By differentiating the Helmholtz free energy with respect to elastic strain, the second Piola-Kirchhoff stress tensor is obtained, and the current stress state of the SMA spring is determined. M44: Based on the inelastic phase transition strain evolution relationship, calculate the phase transition deformation gradient rate of the SMA spring to obtain the phase transition shrinkage deformation amount; M45: Based on the current stress state and phase change shrinkage deformation, outputs the correspondence between the shrinkage driving force and deformation of the SMA spring, which is used for driving pulse parameter calculation and bending posture evaluation.

[0018] The beneficial effects of this invention are as follows: This invention employs a programmable deformation structure consisting of a circumferential SMA spring and a wave lattice unit SMP cylinder. The SMA is responsible for driving the shape, while the SMP relies on temperature changes to achieve stiffness locking. This breaks the limitations of single shape memory materials having limited stable states or insufficient driving force, enabling the structure to have both active driving capability and temperature-controlled shape locking capability. It can maintain its posture at any position within the bending stroke, achieving multi-posture continuous programmable deformation.

[0019] This invention is based on a multi-objective thermal sensing algorithm that combines interpolation preprocessing with K-means clustering. It divides the temperature measurement area into five physical partitions, accurately separating the heating zone, the cylinder wall substrate zone, the heat dissipation zone, and the invalid temperature measurement zone. It extracts dual-feature temperature to match the temperature gradient caused by the thickness of the cylinder, avoiding the data distortion problem caused by single-point temperature measurement and average temperature measurement. It significantly improves the data reliability and control interpretability of SMP closed-loop temperature control, and effectively prevents SMP from failing at the super-melting temperature or failing to soften due to insufficient heating.

[0020] This invention constructs a five-level working condition state machine control logic, which, through standby, large / small stepping, forming, and recovery processes, enables the deformable structure to continue to be programmed to deform from the initial configuration or the locked configuration, and to brake and hold at any intermediate position, thus solving the problem that existing technical solutions can only form once and cannot make fine adjustments in the middle.

[0021] This invention improves response speed through a standby preheating thread, while maintaining the SMP cylinder within a safe range that does not significantly reduce stiffness, thus balancing rapid start-up and attitude stability.

[0022] This invention significantly improves structural stiffness, resilience, and load-bearing capacity by combining built-in air ducts and air cooling to accelerate SMP cooling and curing during the molding stage; and enhances the structure's reusability by unlocking it through a recovery mode and returning it to its initial state.

[0023] This invention links and matches the SMP closed-loop temperature control with the SMA pulse drive, so that the control system only allows the SMA spring to be energized and pulled after the SMP cylinder reaches the low stiffness temperature range. This avoids overloading the SMA, local stress concentration in the SMP cylinder, or damage to the connection parts caused by forcibly driving when the SMP is still in a high stiffness state. At the same time, since each step drive uses the actual temperature state of the SMP as the trigger condition, it can reduce the bending angle deviation caused by inconsistent softening degree, improve the consistency of repeated deformation of the structure, and improve the overall machine coordinated control accuracy.

[0024] This invention employs a composite structure of SMA spring and SMP wave lattice cylinder, combined with K-means multi-target thermal sensing temperature measurement and five-level working condition linkage control. It has both multi-directional active drive and temperature control stiffness locking capability, enabling continuous step deformation and rapid locking at any bending position. It features high temperature control accuracy, good repeatability and consistency, and reliable cyclic use.

[0025] The composite structure of this invention combines active driving and stiffness-locking capabilities, enabling multi-directional programmable continuous deformation. It adopts a combination configuration of circumferentially distributed SMA springs and wave lattice unit SMP cylinders. The SMA springs provide multi-directional bending driving force, while the SMP cylinders achieve high-stiffness glass-state locking and low-stiffness rubber-state deformation through temperature switching. It breaks through the limitations of single shape memory materials, enabling the structure to have both active driving capability and temperature-controlled shape locking capability, and can maintain its posture at any position within the bending stroke, realizing multi-posture continuous programmable deformation.

[0026] The integrated design of the wave lattice hollow cylinder of this invention takes into account load-bearing, shaping and heat dissipation. The SMP cylinder adopts a hollow configuration composed of periodic wave lattice units, which provides bending resistance, torsion resistance and shape retention in the glass state, and provides a low-resistance bending channel in the rubber state. The inside of the cylinder also serves as a thermal control air channel, which, together with the built-in PI heating film and cooling fan, achieves efficient heating and cooling. This solves the problems of traditional structures lacking integrated support and heat dissipation channels, and poor stability under long-stroke deformation and torsional conditions.

[0027] The multi-target thermal sensing temperature measurement scheme of this invention significantly improves the accuracy and reliability of temperature control. Based on infrared thermal array interpolation preprocessing combined with K-means clustering algorithm, the temperature measurement area is divided into five physical zones: SMP main hot zone, SMA local high temperature hot zone, PI heating affected hot zone, ambient heat dissipation hot zone, and background hot zone. The dual-feature temperature is extracted to match the temperature gradient caused by the thickness of the cylinder. It avoids the data distortion problems of single-point temperature measurement and average temperature measurement, effectively prevents SMP from failing at the super-melting temperature or failing to soften due to insufficient heating, and provides accurate data support for closed-loop temperature control and time-series driving.

[0028] The five-level working condition state machine control architecture of this invention supports arbitrary point locking and continuous fine-tuning. It constructs five-level hierarchical control logic, including initialization self-test, standby preheating, step bending, forming locking, and recovery reset, in conjunction with a global emergency stop protection mechanism. This allows the deformable structure to continue programming deformation from the initial configuration or the locked configuration, and to brake and hold at any intermediate position. This solves the problem that the prior art can only form once and cannot make fine-tuning in the middle, and realizes continuous step-by-step programmable adjustment.

[0029] The present invention features an interlocking mechanism between the SMP temperature control and SMA drive, which improves deformation consistency and operational safety. The SMP closed-loop PID temperature control and SMA pulse drive are linked and matched, allowing the SMA spring to be energized and pulled only after the SMP cylinder reaches its low stiffness temperature range. This avoids overloading the SMA, causing localized stress concentration in the SMP, or damage to the connection points due to forced driving while the SMP is still in a high stiffness state. Each step of the drive is triggered by the actual temperature state of the SMP, reducing bending angle deviations caused by inconsistent softening levels and improving the consistency of repeated deformation.

[0030] The air-cooled accelerated cooling and curing of this invention provides fast locking response and strong recyclability. During the molding stage, the built-in air duct and cooling fan provide forced air cooling to accelerate the cooling and curing of SMP, significantly shortening the locking time, greatly improving structural stiffness, and enhancing resistance to springback and load-bearing capacity. In the recovery mode, the structure is reheated and softened, and the SMA spring cooling recovery force and the SMP's own shape memory effect are used to return it to its initial posture, improving the recyclability of the structure.

[0031] The standby preheating mechanism of this invention takes into account both response speed and attitude stability. During the standby preheating stage, the SMP cylinder is maintained in a safe preheating range close to the glass transition temperature without significantly reducing stiffness. This ensures that the cylinder can quickly enter a deformable state after receiving a bending command, while avoiding the decrease in structural stiffness during standby that would affect attitude maintenance, thus balancing rapid start-up and attitude stability. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall structure of the programmable deformable structure in this invention; Figure 2 This is a front view of the programmable deformable structure in this invention; Figure 3 This is a schematic diagram of the wave lattice unit structure of the SMP cylinder in this invention; Figure 4 This is a top-view cross-sectional view of the present invention; Figure 5 A flowchart for the overall model management process; Figure 6 Flowchart for initialization and standby mode.

[0033] The symbols for each component are as follows: 1. Upper connecting plate; 2. SMA spring; 3. SMP cylinder; 4. Lower connecting plate. Detailed Implementation

[0034] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0035] Example: like Figure 1 As shown, the multi-polymer synergistic thermally controlled deformation structure includes an upper connecting plate 1, at least three SMA springs 2, an SMP cylinder 3, and a lower connecting plate 4. The upper connecting plate 1 and the lower connecting plate 4 are preferably polymethyl methacrylate (PMMA) plates. In this embodiment, three SMA springs 2 are preferably provided, arranged at 120° angles to the central axis of the SMP cylinder 3. The upper connecting plate 1 and the lower connecting plate 4 are fixed parallel to each other on both sides of the SMP cylinder 3. The axis of the SMP cylinder 3 is perpendicular to the upper connecting plate 1. Each SMA spring 2 is fixedly connected to both sides of the upper connecting plate 1 and the lower connecting plate 4, respectively. Each SMA spring 2 is evenly distributed around the outer circumference of the SMP cylinder 3 between the upper connecting plate 1 and the lower connecting plate 4. When the SMA springs 2 are in their normal state, the axes of several SMA springs 2 are parallel to the axis of the SMP cylinder 3. The normal state is when the SMA springs 2 are in their natural state without being energized and without undergoing phase change contraction. The SMP cylinder 3, located at the structural center, serves as the core for stiffness adjustment and shape locking. Three SMA springs act as the driving source, with their ends connected to the upper connecting plate 1 and the lower connecting plate 4, respectively, to generate unilateral or combined contraction torques. The SMP cylinder 3 adopts a hollow cylindrical configuration, defined by a wave lattice unit. This structure provides bending, torsional, and shape-holding capabilities in the glassy state. In the rubbery state, it provides a low-resistance bending channel, allowing the SMA springs 2 to drive the structure to deform in a specified direction. Mounting holes for the SMP cylinder 3 are provided on the upper connecting plate 1 and the lower connecting plate 4, with both ends of the SMP cylinder 3 fixedly connected to these holes. Spring mounting holes for the SMA springs 2 are also provided on both the upper connecting plate 1 and the lower connecting plate 4, with both ends of the SMA springs 2 fixed within these holes.

[0036] like Figure 2 , Figure 3 and Figure 4As shown, the SMP cylinder 3 is composed of several periodically arranged wave lattice units. Each wave lattice unit consists of periodically undulating wavy lattice walls. The peaks and troughs of adjacent lattice units intersect tangentially and solidify into one unit. Several wave lattice units are continuously arranged along the circumferential and axial directions and interconnected to form a hollow cylindrical lattice structure. (See figure) The horizontal coordinate axis is... The vertical coordinate axes are used for coordinates. The SMP cylinder length is 220. , The inner diameter of the SMP cylinder is 17.5 mm. , The SMP cylinder wall thickness is 2.5mm; The height of the wave lattice unit is 8.97 mm. The total length of the wave lattice unit cell is 23.21 mm. The inter-unit spacing of the wave lattice is 21.21 mm. The upper layer of the wave lattice unit is 1.48 mm thick. The thickness of the lower layer of the wave lattice unit is 3.72 mm; The SMA spring is 2.3mm thick. The SMA spring has a diameter of 6.15mm; The radius of the distribution circle for the SMA spring mounting holes is 55mm, which is the distance from the center of the spring hole to the center of the circle; The total diameter of the connecting plate is 126mm. The connecting plate thickness is 3mm. For example... Figure 3 This is a schematic diagram of the wave lattice unit.

[0037] A flexible PI heating film is provided on the inner surface of the SMP cylinder 3. A thermal control air channel is formed inside the SMP cylinder 3, and a cooling fan is provided at one end of the thermal control air channel to drive airflow axially through the thermal control air channel for heat dissipation. The PI heating film is used to heat the SMP, and the cooling fan is used to quickly dissipate heat along the thermal control air channel. An infrared thermal array sensor is provided on the inner surface of the SMP cylinder 3 to collect two-dimensional temperature matrix data of the deformable structure surface in real time. It also includes an upper controller, a lower controller, a PWM temperature control module, and an SMA drive module. The cooling fan is electrically connected to the lower controller. The PWM temperature control module is electrically connected to the flexible PI heating film. The SMA drive module is electrically connected to the SMA spring 2. The upper controller is communicatively connected to the lower controller and the infrared thermal array sensor. The upper controller is equipped with an instruction parsing module and a K-means multi-target thermal sensing module. The instruction parsing module is used to receive user interaction actions. The upper controller is also equipped with a temperature interpolation module to interpolate the two-dimensional temperature matrix data collected by the infrared thermal array sensor to obtain an interpolated temperature matrix. The K-means multi-target thermal sensing module is used to perform unsupervised partitioning of the interpolated temperature matrix and identify SMP target hot zones from the temperature image and calculate the target temperature. The K-means multi-target thermal sensing module is configured to perform the following operations: perform unsupervised clustering partitioning on the temperature matrix acquired by the infrared thermal array sensor and after interpolation, dividing the temperature image into SMP main hot zones, SMA local high-temperature hot zones, PI heating-affected hot zones, ambient heat dissipation hot zones, and background hot zones; identify the SMP target hot zones from these zones; and output the average temperature of the target hot zone as the target temperature.

[0038] An infrared thermal array sensor serves as the detection component, used to acquire two-dimensional temperature matrix data of the deformable structure surface in real time and transmit it to the upper controller. The upper controller communicates with the infrared thermal array sensor and the lower controller. Internally, it includes an instruction parsing module and a K-means multi-target thermal sensing module for parsing action commands, processing global temperature data, and sending action commands down to the lower level. The lower controller internally includes a PI heating film PWM drive channel, a cooling fan control channel, and an SMA spring MOSFET drive channel to receive commands from the upper controller and output corresponding PWM and switching signals. The cooling fan is electrically connected to the lower controller's cooling fan control channel for rapid forced cooling of the SMP cylinder during the forming and locking stage. The PWM temperature control module connects the lower controller's PI heating film PWM drive channel to the flexible PI heating film, dynamically adjusting the heating power of the PI heating film. The PWM temperature control module can utilize the existing mature IRF520 MOSFET drive module. The SMA drive module connects the SMA spring MOSFET drive channel of the lower-level controller to each SMA spring, and is used to control the energization and contraction of a specified SMA spring. The SMA drive module can use the existing mature AOD4184 high-power MOSFET switching module.

[0039] A method for controlling the thermally deformable structure of multiple polymers includes the following steps: S1: The upper-level controller and lower-level controller initialize and perform self-tests. After confirming that everything is normal, a temperature monitoring and execution control closed loop is established, and the process proceeds to the next step, S2; specifically: S11: After starting the upper controller and lower controller, the upper controller first completes the initialization configuration of the infrared thermal array sensor, K-means multi-target thermal sensing module, and instruction parsing module. The lower controller simultaneously completes the initialization configuration of the PI heating film PWM drive channel, cooling fan control channel, and SMA spring MOSFET drive channel. The instruction parsing module is used to receive user interaction actions. S12: The validity of the output of the infrared thermal array sensor is verified by checking the data integrity and temperature range, with the criteria being that the data matrix is ​​free of omissions and abnormal out-of-bounds values; if the verification result is valid, proceed to step S13; if the verification is invalid, directly enter the fault protection state; the conventional communication error verification, temperature data matrix integrity verification and temperature range threshold comparison methods in this field are used. S13: Detects the operating status of the upper controller communication link, lower controller communication link, PI heating film circuit, cooling fan circuit, and SMA drive module. Based on the detected operating status results, it determines whether to trigger an emergency stop, and if triggered, the protection enters fault protection mode; specifically: If at least one of the following is detected to be in an abnormal working state: the upper controller communication link, the lower controller communication link, the PI heating film circuit, the cooling fan circuit, or the SMA drive module, all outputs are immediately locked and the system enters a fault protection state; otherwise, a temperature monitoring and execution control closed loop is established, and the system enters the standby preheating mode of the next step S2.

[0040] S2: SMP cylinder preheating stage: After the SMP cylinder is preheated to a low stiffness softening state in the initial posture, it enters the S3 step bending stage after receiving the step bending command input by the user through the interactive interface; Specifically: After the control system enters the standby preheating mode, the control system simultaneously performs command listening and real-time temperature monitoring. S21: The host controller sequentially calls the infrared temperature matrix acquisition and interpolation method M1 and the K-means multi-target thermal sensing model M2 to identify the target hot zone of the SMP cylinder 3 and calculate the real-time temperature of the SMP target hot zone. ; S22: Call the viscoelastic temperature change equivalent model M3 to determine the stiffness state of the SMP cylinder 3 in real time. The stiffness state includes a high-stiffness glass state and a low-stiffness rubber state. S23: Based on the real-time temperature of the target hot zone in the SMP system. To mitigate the deviation from the preset preheating temperature threshold, the upper-level controller uses a PID closed-loop temperature control algorithm to gradually increase the temperature of the SMP cylinder 3 in its initial state. This PID closed-loop temperature control algorithm is used to maintain the temperature of the SMP cylinder 3 stably within the preheating range of its low-stiffness rubber state. The upper-level controller calculates the control input and instructs the temperature control module via the lower-level controller to adjust the closed-loop output, thus gradually increasing the temperature of the SMP cylinder 3 in its initial state. The target preheating temperature is a parameter pre-set based on the glass transition temperature of the SMP material, and the preheating range is a tolerance range for fluctuations around this target preheating temperature. The PID closed-loop temperature control algorithm in step S23 is a common existing algorithm, specifically: The upper controller sets the target temperature according to the current mode. The current feedback temperature is calculated by the multi-target thermal sensing system. The error was obtained. The PID controller outputs the control quantity based on the proportional error, integral error, and derivative error. The controller converts this control quantity into a PWM duty cycle, fan control signal, or temperature control execution command. The lower-level controller adjusts the PI heating film and cooling fan according to this command, enabling the SMP temperature to rapidly approach the target range and suppress oscillations. When the system is in heating mode, the control quantity mainly acts on the PI heating film; when the system is in cooling or forming lock mode, the control quantity mainly acts on the cooling fan, and the PI heating film is turned off if necessary. For SMA springs, since precise temperature control is not required, the controller outputs short pulses, step pulses, or continuous energizing commands through the SMA drive module to achieve bending in a specified direction and amplitude. S24: After the SMP cylinder 3 reaches the low-stiffness rubber state, keep all SMA drive circuits de-energized and continue to wait for action commands; S25: When the upper controller receives the step bending command input by the user, it proceeds to step S3; when it receives the recovery reset command, it proceeds to step S5; when it receives an abnormal trigger, it enters the emergency stop protection state, that is, it proceeds to step S6. S3: Stepping Bending Phase: After completing the target number of steps or target posture in stepping bending, stop SMA driving and enter the S4 shaping and locking phase; specifically: S31: After receiving the step bending command, the upper controller uses the command parsing module to extract the features of the input command string, and parses out the bending direction parameters (i.e., the target SMA spring number), the number of execution steps (i.e., the number of action pulses), and the step type parameters (i.e., the pulse width pattern). It then calls the infrared temperature matrix acquisition and interpolation method M1 and the K-means multi-target thermal sensing model M2 to obtain the current temperature information of the SMP cylinder 3, and uses the viscoelastic temperature change equivalent model M3 to determine whether the SMP cylinder 3 has reached the low stiffness softening state. When the SMP cylinder 3 is preheated to the low stiffness rubber state, the upper controller releases the safety state that prohibits the SMA from being powered on, and allows current output; otherwise, it continues to return to step S2 to preheat the SMP cylinder 3 until it reaches the low stiffness softening state. S32: The upper controller selects the corresponding SMA spring 2 according to the bending direction parameters obtained from S31, and calculates the required driving pulse parameters using the SMA thermo-coupling constitutive model M4, in conjunction with the execution step number parameters and step type parameters obtained from the analysis. Then, it instructs the lower controller to output the driving pulse through the SMA driving module, so that the target SMA spring 2 heats up and contracts in a phase change, completing a single step action. S33: After a single step action is completed, the upper controller calls the infrared temperature matrix acquisition and interpolation method M1 and the K-means multi-objective thermal sensing model M2 to acquire temperature and identify hot zones, calls the viscoelastic temperature change equivalent model M3 to determine the stiffness state of the SMP cylinder 3, and combines the SMA thermo-coupling constitutive model M4 to evaluate the current bending attitude; specifically: If the evaluation results show that the set number of execution steps or target posture has been reached, the step bending phase ends and the next step S4 is automatically entered. If the evaluation result shows that the set number of execution steps or target posture has not been reached, return to step S32, continue to calculate and output the next drive pulse to perform the stepping action until the target posture is reached; S4: Forming and locking control stage; after cooling and locking, the structure maintains its current configuration for an extended period, while simultaneously returning to the command listening state, awaiting a secondary deformation or reset command; specifically: S41: When a forming command is received or the step bending reaches the target posture, the lower controller shuts down or reduces the output power of the PI heating film and starts the cooling fan to cool down the SMP cylinder 3. S42: During the cooling process, the infrared temperature matrix acquisition and interpolation method M1 and the K-means multi-objective thermal sensing model M2 are continuously invoked to detect the real-time temperature of the SMP target hot zone of the SMP cylinder 3. The stiffness state of the SMP cylinder 3 is determined in real time by combining the viscoelastic temperature change equivalent model M3. S43: Real-time temperature of the SMP target hot zone The temperature drops to the locking temperature threshold, which is preset based on the characteristics of SMP material. After this state is maintained for a preset time, it is determined that the SMP cylinder 3 has recovered to the high-stiffness glass state, that is, the physical locking of the current bending posture is achieved by using the high-stiffness glass state itself. S44: After the current bending posture is locked, turn off the cooling fan and keep all SMA spring 2 drives de-energized, so that the SMP cylinder 3 maintains the current bending posture. At the same time, the upper controller continues to listen and wait to receive user commands. When the next bending posture deformation command is received, return to step S3. When the recovery reset command is received, proceed to the next step S5. When the abnormal trigger command is received, proceed to step S6. S5: Reset Phase; Upon receiving a reset command, the system enters the S5 reset phase. After reset, it automatically returns to the S2 standby warm-up mode. Specifically: S51: After the host controller receives the reset command, it restarts the PI heating film to heat the SMP cylinder 3, and obtains the real-time temperature of the SMP target hot zone of the SMP cylinder 3 in real time through infrared temperature matrix acquisition and interpolation method M1 and K-means multi-objective thermal sensing model M2. Then, the viscoelastic temperature change equivalent model M3 is used to determine whether the SMP cylinder 3 has returned to the low stiffness rubber state. S52: When the SMP cylinder 3 reaches the low-stiffness rubber state, the SMP cylinder 3 regains its deformation freedom. S53: After the SMP cylinder 3 recovers its deformation degrees of freedom, it is combined with the SMA thermo-coupling constitutive model M4. The restoring force of the SMA spring 2 after cooling and stretching back to its original length, together with the shape memory recovery effect of the SMP cylinder 3 itself, jointly drive the SMP cylinder 3 to return to its initial posture. The SMP cylinder 3 returns to its initial posture and enters the next step. S54: After the SMP cylinder returns to its initial position or when the upper controller receives an interactive command from the user confirming the completion of the reset, the drive power supply of the PI heating film and all SMA springs is turned off, and the process returns to step S2; S6: During the operation of steps S2 to S5, the control system synchronously executes emergency stop monitoring step S6, which specifically includes: S61: During the operation of steps S2 to S5, abnormal information is monitored in real time. Abnormal information includes electrical abnormalities of the PI heating film circuit, cooling fan circuit and SMA drive module defined in step S1, as well as temperature exceeding the limit in the temperature monitoring closed-loop feedback in steps S2-S5. S62: When abnormal information is detected, the control system immediately calls the infrared temperature matrix acquisition and interpolation method M1 and the K-means multi-objective thermal sensing model M2 to complete the thermal zone identification of the SMP main body hot zone, the SMA local high temperature hot zone and the background hot zone. It also combines the viscoelastic temperature change equivalent model M3 and the SMA thermo-coupling constitutive model M4 to determine whether the current temperature of the SMP cylinder 3 and the SMA spring 2 exceeds the safe operating range preset in the upper controller. The safe operating range is based on the overheating melting temperature boundary of the SMP material and the allowable maximum phase change temperature boundary of the SMA spring, which are pre-calibrated and stored in the upper controller. S63: If step S62 determines that the safe operating range is exceeded, then immediately cut off the power supply to all SMA drive circuits and PI heating film; if the temperature exceeds the safe temperature threshold preset by the upper controller, then start the cooling fan for forced heat dissipation, otherwise maintain the fan as before; if it is determined that the safe operating range is not exceeded, then maintain the current operating state of the system. S64: After the temperature recovers to the safe temperature range preset in the upper controller (i.e., below the melting overheating temperature of SMP and in the normal phase change safe zone of SMA) and the fault is eliminated, return to step S2; if the upper controller detects that the drive circuit current is continuously abnormal or the sensor data is missing, it is determined to be an unrecoverable hardware fault. The upper controller immediately triggers the fault lock state, cuts off all function outputs, and waits for manual reset after the hardware fault is eliminated. M1: Infrared Temperature Matrix Acquisition and Interpolation Method; The infrared temperature matrix acquisition and interpolation model is used to preprocess the raw temperature data acquired by the infrared array sensor through interpolation, providing a high-resolution temperature matrix for subsequent hot zone identification and temperature detection. The infrared array sensor is used to acquire two-dimensional temperature information of the deformable structure surface, with an original resolution of 32×24. Since the original resolution is insufficient to accurately delineate the target hot zone, the original temperature matrix needs to undergo three interpolation processes before being used for subsequent K-means hot zone identification; the specific steps include the following: M11: Reads the raw two-dimensional temperature matrix data acquired by the infrared thermal array sensor. The raw resolution of the temperature matrix is ​​32×24. Specifically: Let the first The original temperature matrix collected in each control cycle is as follows: ; In the formula, The first in the infrared thermal array line, number The temperature values ​​of the listed temperature points, This represents the system control cycle number, and 32×24 represents the original resolution of the infrared array sensor. M12: A cubic interpolation algorithm is used to upsample and interpolate the original temperature matrix, resulting in an improved interpolated temperature matrix for subsequent K-means thermal region identification; specifically: Perform cubic interpolation on the original temperature matrix to obtain the interpolated temperature matrix: ; In the formula, This is a cubic interpolation function used to perform cubic spline interpolation operations on the input matrix. This is the interpolated high-resolution temperature matrix; In step S1, the infrared temperature matrix acquisition and interpolation model is used to determine whether the infrared sensor outputs a valid temperature matrix; in step S2, the infrared temperature matrix acquisition and interpolation model is used for standby preheating temperature identification; in step S3, the infrared temperature matrix acquisition and interpolation model is used for SMP temperature determination before and during step bending; in step S4, the infrared temperature matrix acquisition and interpolation model is used for cooling lock-shaped temperature determination; in step S5, the infrared temperature matrix acquisition and interpolation model is used for SMP softening state determination during recovery; and in step S6, it is used for abnormal temperature detection. M2: K-means multi-objective thermal sensing model; the K-means multi-objective thermal sensing model uses the K-means clustering algorithm to perform unsupervised partitioning of the interpolated temperature matrix, identifies SMP target hot zones from the temperature image and calculates the target temperature, and is used to cooperate with the temperature control of SMA-SMP deformable structures. Temperature is the only feature in the clustering process. The temperature image is divided into different thermal target regions through clustering methods; specifically, it includes the following steps: M21: Set the number of clusters and initial cluster centers; using each temperature data point in the interpolated temperature matrix as a sample, set the number of clusters to... and initialize Cluster centers; Let the interpolated temperature data points be... , , Represents the first element in the interpolated temperature matrix. One temperature data point, This represents the total number of temperature points. Set the number of clusters to and cluster center as , ; M22: Calculate the distance between temperature data points and cluster centers; calculate the distance from each temperature data point to each cluster center separately; The distance from each temperature data point to the cluster center is: ; M23: Data point cluster allocation; each temperature data point is assigned to the cluster corresponding to the nearest cluster center, forming multiple temperature data point sets; Divide the temperature data points into the nearest cluster centers: ; In the formula, Representing data points With cluster center The Euclidean distance between them The index variable for the cluster centers. For the first The set of temperature data points contained in each cluster; M24: Update cluster centers; recalculate the average value of all temperature data points within each cluster and use this average value as the new cluster center for the corresponding cluster; Update cluster centers: ; M25: Iterative convergence judgment; Repeat steps M22 to M24 until the change in each cluster center meets the convergence condition, and the clustering is completed. M26: Target hot zone selection; Select the SMP main hot zone as the target hot zone from multiple hot zones obtained by clustering; In this invention, the clustered hot zones correspond one-to-one with the five theoretically defined characteristic regions, which, in the corresponding order, may include the SMP main hot zone, the SMA local high-temperature hot zone, the PI heating-affected hot zone, the environmental heat dissipation hot zone, and the background hot zone. The SMP main hot zone is selected. As the primary target hot zone: ; M27: Target Temperature Calculation; Calculates the average temperature of all temperature data points within the SMP main body thermal zone, and outputs the real-time temperature of the SMP target thermal zone. And calculate the real-time temperature of the target hot zone in SMP: ; In the formula, For the first Real-time temperature of the target hot zone in the SMP cylinder during each control cycle.

[0041] In step S2, Used for standby preheating control; in step S3 Used to determine whether SMA stepper drive is allowed; in step S4 Used to determine whether cooling lock-up is complete; in step S5. Used to determine whether the SMP has re-entered a low-stiffness state; in step S6, with Temperatures of other hot zones are used to determine whether a temperature breach has occurred; M3: SMP generalized Maxwell viscoelastic model and WLF temperature-time equivalent model (viscoelastic temperature change equivalent model); specifically including the following steps: The viscoelastic temperature-dependent equivalent model uses the superimposed generalized Maxwell model and WLF equation to describe the viscoelastic properties and temperature dependence of SMP, which is used to reveal the relationship between temperature change and stiffness change of SMP, and to provide a theoretical basis for the state judgment of preheating, softening, shaping and recovery stages. M31: Obtain the real-time temperature of the target hot zone of SMP at the current moment, and establish the correspondence between the relaxation modulus of SMP material and time based on the superimposed generalized Maxwell viscoelastic model to characterize the viscoelastic properties of SMP. The generalized Maxwell model of SMP is represented as follows: ; In the formula, for Constant stress, For the initial strain, For instantaneous modulus, For the first The elastic modulus of each Maxwell branch, For the first The relaxation time of each Maxwell branch This represents the total number of Maxwell branches. This is the Maxwell branch index variable.

[0042] The relaxation modulus is: ; And satisfy: ; M32: Using the WLF temperature-time equivalence relationship, the SMP relaxation time at different temperatures is equivalently converted to obtain the influence law of temperature on the SMP relaxation response speed; WLF Temperature-Time Equivalence: To describe the effect of temperature on the relaxation time and modulus response rate of SMP, the WLF temperature-time equivalence is adopted. Specifically: ; In the formula, It is the displacement factor. The relaxation time at the current temperature. Relaxation time at reference temperature, The current temperature. For reference temperature, , These are material constants; M33: Using the glass transition temperature of the SMP material as the threshold, the real-time temperature of the target hot zone of the SMP is compared with the glass transition temperature. When the real-time temperature of the target hot zone of the SMP is lower than the glass transition temperature, the SMP cylinder is determined to be in a high-stiffness glassy state, suitable for lock-fitting. When the real-time temperature of the target hot zone of the SMP is higher than or equal to the glass transition temperature, the SMP cylinder is determined to be in a low-stiffness rubbery state, suitable for SMA spring-driven deformation or shape recovery. Specifically: SMP stiffness condition determination: based on current temperature The real-time temperature of the corresponding SMP target hot zone can be obtained from M2. Characterization, based on Glass transition temperature Determine the stiffness state of the SMP: when At this time, SMP is in a high-stiffness glassy state, which is suitable for lock-type applications; when When this occurs, the SMP enters a low-stiffness rubber state, making it suitable for deformation or recovery driven by the SMA spring.

[0043] In step S2, the viscoelastic temperature change equivalent model is used to determine that the standby preheating temperature should not cause the SMP to remain in an over-softened state for an extended period of time; in step S3, the viscoelastic temperature change equivalent model is used to determine whether the SMP has reached the low stiffness temperature range; in step S4, the viscoelastic temperature change equivalent model is used to determine whether the SMP has cooled back to a high stiffness lock-in state; in step S5, the viscoelastic temperature change equivalent model is used to determine whether the SMP has re-softened and is allowed to recover; and in step S6, it is used to determine the safe temperature boundary of the SMP. M4: SMA thermo-coupled constitutive model; specifically including the following steps: M41: Obtain the current state parameters of the SMA spring, including the current temperature, martensite volume fraction, and elastic strain; The SMA thermo-mechanical coupling constitutive model is used to describe the mechanical mechanism of the contraction driving force generated by the SMA spring after energization and heating, as well as the cooling and recovery. The finite element method is used to model the behavior of the SMA, and the phase transition behavior of the SMA is simulated based on the isotropic thermomechanical constitutive model. ; In the formula, The total free energy density; , , These are the elastic energy density, phase transition free energy density, and pure thermal free energy density, respectively. M42: Based on the isotropic thermomechanical constitutive framework, the total free energy density of the SMA spring is decomposed into three parts: elastic performance density, phase transition free energy density, and pure thermal free energy density, which are calculated separately. The expressions for each part are as follows: ; ; ; In the formula, For elastic strain, It is a fourth-order elastic modulus tensor. For thermal expansion tensor, This is the current temperature of the SMA. For SMA reference temperature, This represents the volume fraction of martensite. The latent heat constant of phase transition, The phase transition temperature; M43: By differentiating the Helmholtz free energy with respect to elastic strain, the second Piola-Kirchhoff stress tensor is obtained, and the current stress state of the SMA spring is determined. The second Piola-Kirchhoff stress tensor can be obtained by differentiating the Helmholtz free energy: ; In the formula, For the second Piola-Kirchhoff stress second-order tensor, The total free energy density; M44: Based on the inelastic phase transition strain evolution relationship, calculate the phase transition deformation gradient rate of the SMA spring to obtain the phase transition shrinkage deformation amount; Inelastic phase transition distortion satisfies: ; In the formula, For inelastic deformation gradient rate tensor, For the maximum phase transition strain, For inelastic flow direction, This represents the inelastic phase transition distortion gradient.

[0044] M45: Based on the spring stress state and phase change contraction deformation, outputs the correspondence between the contraction driving force and deformation of the SMA spring, which is used for driving pulse parameter calculation and bending posture evaluation. In step S3, when the downstream controller energizes the target SMA spring, the SMA temperature rises, and the martensite volume fraction increases. Changes occur, resulting in stress and shrinkage deformation, which drives the SMP cylinder to bend. In step S5, the SMA spring cooling or auxiliary energizing pulse generates a recovery effect, which, together with the low-stiffness SMP cylinder, completes the initial shape recovery. In step S6, the SMA thermo-coupling constitutive model is used to determine whether the SMA temperature is within the safe operating range, avoiding overheating that could lead to performance degradation.

Claims

1. A multi-polymer synergistic thermally controlled deformation structure, characterized in that, The device includes an upper connecting plate (1), at least three SMA springs (2), an SMP cylinder (3), and a lower connecting plate (4). The upper connecting plate (1) and the lower connecting plate (4) are fixed parallel to each other on both sides of the SMP cylinder (3). The axis of the SMP cylinder (3) is perpendicular to the upper connecting plate (1). The two sides of each SMA spring (2) are fixedly connected to the upper connecting plate (1) and the lower connecting plate (4) respectively. Each SMA spring (2) is evenly distributed around the outer circumference of the SMP cylinder (3) between the upper connecting plate (1) and the lower connecting plate (4). When the SMA springs (2) are in normal condition, the axes of several SMA springs (2) are parallel to the axis of the SMP cylinder (3). The SMP cylinder (3) is composed of several periodically arranged wave lattice units. The wave lattice units are composed of periodically undulating wave-shaped lattice walls. The peaks and valleys of adjacent lattice units are connected accordingly. Several wave lattice units are continuously arranged along the circumferential direction and the axial direction and connected to each other to form a hollow cylindrical lattice structure. The SMP cylinder (3) has a flexible PI heating film on its inner surface. A thermal control air channel is formed inside the SMP cylinder (3). A cooling fan is provided at one end of the thermal control air channel. An infrared thermal array sensor is provided on the inner surface of the SMP cylinder (3). The infrared thermal array sensor is used to collect two-dimensional temperature matrix data of the deformable structure surface in real time. It also includes an upper controller, a lower controller, a PWM temperature control module and an SMA drive module; the cooling fan is electrically connected to the lower controller; the PWM temperature control module is electrically connected to the flexible PI heating film; the SMA drive module is electrically connected to the SMA spring (2); the upper controller is connected to the lower controller and the infrared thermal array sensor for communication; the upper controller is equipped with an instruction parsing module and a K-means multi-target thermal sensing module. The instruction parsing module is used to receive user interaction actions. The upper controller is also equipped with a temperature interpolation module, which is used to interpolate the two-dimensional temperature matrix data collected by the infrared thermal array sensor to obtain the interpolated temperature matrix.

2. The multi-polymer synergistic thermally controlled deformation structure according to claim 1, characterized in that, The upper connecting plate (1) and the lower connecting plate (4) are provided with mounting limit holes that cooperate with the SMP cylinder (3), and the two ends of the SMP cylinder (3) are fixedly connected to the mounting limit holes.

3. The multi-polymer synergistic thermally controlled deformation structure according to claim 1, characterized in that, Both the upper connecting plate (1) and the lower connecting plate (4) are provided with spring mounting holes for installing SMA springs (2), and the two ends of the SMA springs (2) are fixed in the spring mounting holes.

4. The multi-polymer synergistic thermally controlled deformation structure according to claim 1, characterized in that, There are three SMA springs (2), and the three SMA springs (2) are arranged at 120° with the central axis of the SMP cylinder (3) as the reference.

5. A method for controlling the thermally controlled deformation structure of a multi-polymer synergistic structure according to any one of claims 1-4, characterized in that, Includes the following steps: S1: The upper-level controller and lower-level controller initialize and perform self-tests. After confirming that everything is normal, a temperature monitoring and execution control closed loop is established, and the process proceeds to the next step, S2; specifically: S11: After starting the upper controller and the lower controller, the upper controller first completes the initialization configuration of the infrared thermal array sensor, the K-means multi-target thermal sensing module and the instruction parsing module, and the lower controller simultaneously completes the initialization configuration of the PI heating film PWM drive channel, the cooling fan control channel and the SMA spring MOSFET drive channel. S12: By checking the data integrity and temperature range, the validity of the output of the infrared thermal array sensor is verified based on the criteria that the data matrix is ​​free of omissions and abnormal out-of-bounds values. If the verification result is valid, proceed to step S13; otherwise, directly enter the fault protection state. S13: Detects the working status of the upper controller communication link, lower controller communication link, PI heating film circuit, cooling fan circuit and SMA drive module, and determines whether to trigger emergency stop protection based on the detected working status results, and enters fault protection state when triggered. If at least one of the following is detected to be in an abnormal working state: the upper controller communication link, the lower controller communication link, the PI heating film circuit, the cooling fan circuit, or the SMA drive module, all outputs are immediately locked and the system enters a fault protection state; otherwise, a temperature monitoring and execution control closed loop is established, and the system enters the standby preheating mode of the next step S2. S2: SMP cylinder preheating stage; After preheating the SMP cylinder to a low-stiffness softened state from its initial posture, it enters the S3 step bending stage upon receiving the step bending command input by the user through the interactive interface; Specifically: S21: The upper controller sequentially calls the infrared temperature matrix acquisition and interpolation method and the K-means multi-target thermal sensing model to identify the target hot zone of the SMP cylinder (3) and calculate the real-time temperature of the SMP target hot zone; S22: Call the viscoelastic temperature change equivalent model to determine the stiffness state of the SMP cylinder (3) in real time. The stiffness state includes high stiffness glass state and low stiffness rubber state. S23: Based on the deviation between the real-time temperature of the SMP target hot zone and the preset preheating temperature threshold, the upper controller gradually heats up the SMP cylinder (3) in the initial state through the PID closed-loop temperature control algorithm, and adjusts it through the PID closed-loop temperature control algorithm to keep the temperature of the SMP cylinder (3) stable within the preheating range of low stiffness rubber state. S24: After the SMP cylinder (3) reaches the low stiffness rubber state, keep all SMA drive circuits de-energized and continue to wait for action commands; S25: When the upper controller receives the step bending command input by the user, it proceeds to step S3; when it receives the recovery reset command, it proceeds to step S5; when it receives an abnormal trigger, it enters the emergency stop protection state. S3: Stepping Bending Phase; After completing the target number of steps or target posture in stepping bending, stop SMA driving and enter the S4 shaping and locking phase; Specifically: S31: After receiving the step bending command, the upper controller uses the command parsing module to extract the features of the input command string, parses out the bending direction parameters, execution step parameters and step type parameters involved in the drive, and calls the infrared temperature matrix acquisition and interpolation method and K-means multi-objective thermal sensing model to obtain the current temperature information of the SMP cylinder (3), and judges whether the SMP cylinder (3) has reached the low stiffness softening state through the viscoelastic temperature change equivalent model; when the SMP cylinder (3) is preheated to the low stiffness rubber state, the upper controller releases the safety state that prohibits the SMA from being powered and allows the current output; otherwise, it continues to return to step S2 to preheat the SMP cylinder (3) until it reaches the low stiffness softening state; S32: The upper controller selects the corresponding SMA spring (2) according to the bending direction parameters obtained from S31, and calculates the required driving pulse parameters using the SMA thermo-coupling constitutive model in combination with the execution step parameters and step type parameters obtained from the analysis; then instructs the lower controller to output the driving pulse through the SMA driving module, so that the target SMA spring (2) heats up and contracts in a phase change, completing a single step action; S33: After a single stepping action is completed, the upper controller calls the infrared temperature matrix acquisition and interpolation method and the K-means multi-target thermal sensing model to acquire temperature and identify hot zones, calls the viscoelastic temperature change equivalent model to judge the stiffness state of the SMP cylinder (3), and combines the SMA thermo-coupling constitutive model to evaluate the current bending posture; if the evaluation result shows that the set number of execution steps or target posture has been reached, the stepping bending stage ends and automatically enters the next step S4; if the evaluation result shows that the set number of execution steps or target posture has not been reached, the controller returns to step S32, continues to calculate and output the next driving pulse to perform the stepping action until the target posture is reached. S4: Forming and locking control stage; after cooling and locking, the structure maintains its current configuration for an extended period, while simultaneously returning to the command listening state, awaiting a secondary deformation or reset command; specifically: S41: When a forming command is received or the step bending reaches the target posture, the lower controller shuts down or reduces the output power of the PI heating film and starts the cooling fan to cool down the SMP cylinder (3); S42: During the cooling process, the infrared temperature matrix acquisition and interpolation method and the K-means multi-target thermal sensing model are continuously called to detect the real-time temperature of the SMP target hot zone of the SMP cylinder (3) in real time, and the stiffness state of the SMP cylinder (3) is judged in real time by combining the viscoelastic temperature change equivalent model. S43: When the real-time temperature of the SMP target hot zone drops to the lock-in temperature threshold and this state is maintained for a preset time, it is determined that the SMP cylinder (3) has recovered to the high-rigidity glass state, that is, the physical locking of the current bending posture is achieved by using the high-rigidity glass state itself. S44: After the current bending posture is locked, turn off the cooling fan and keep all SMA springs (2) driven off, so that the SMP cylinder (3) maintains the current bending posture. At the same time, the upper controller continues to listen and wait to receive user instructions. When the next bending posture deformation instruction is received, return to step S3. When the recovery reset instruction is received, proceed to the next step S5. When the abnormal trigger instruction is received, proceed to step S6. S5: Reset Phase; Upon receiving a reset command, the system enters the S5 reset phase. After reset, it automatically returns to the S2 standby warm-up mode. Specifically: S51: When the upper controller receives the recovery reset command, it restarts the PI heating film to heat the SMP cylinder (3), and obtains the real-time temperature of the SMP target hot zone of the SMP cylinder (3) in real time through the infrared temperature matrix acquisition and interpolation method and the K-means multi-objective thermal sensing model. Then, it uses the viscoelastic temperature change equivalent model to determine whether the SMP cylinder (3) has reached the low stiffness rubber state again. S52: When the SMP cylinder (3) reaches the low stiffness rubber state, the SMP cylinder (3) restores its deformation freedom; S53: After the SMP cylinder (3) recovers its deformation degree of freedom, it combines the SMA thermo-coupling constitutive model and utilizes the restoring force of the SMA spring (2) after cooling and stretching back to its original length. Combined with the shape memory restoration effect of the SMP cylinder (3) itself, it drives the SMP cylinder (3) to return to its initial posture. The SMP cylinder (3) returns to its initial posture and enters the next step. S54: After the SMP cylinder returns to its initial position or when the upper controller receives an interactive command from the user confirming the completion of the reset, the drive power supply of the PI heating film and all SMA springs (2) is turned off, and the process returns to step S2.

6. The control method for the multi-polymer synergistic thermally controlled deformation structure according to claim 5, characterized in that, During the operation of steps S2 to S5, the control system synchronously executes emergency stop monitoring step S6, which specifically includes: S61: During the operation of steps S2 to S5, abnormal information is monitored in real time. Abnormal information includes electrical abnormalities of the PI heating film circuit, cooling fan circuit and SMA drive module defined in step S1, as well as temperature exceeding the limit in the temperature monitoring closed-loop feedback in steps S2-S5. S62: When abnormal information is detected, the control system immediately calls the infrared temperature matrix acquisition and interpolation method and the K-means multi-objective thermal sensing model to complete the thermal zone identification of the SMP main body hot zone, the SMA local high temperature hot zone and the background hot zone, and combines the viscoelastic temperature change equivalent model and the SMA thermo-coupling constitutive model to determine whether the current temperature of the SMP cylinder (3) and the SMA spring (2) exceeds the safe working range preset in the upper controller. S63: If step S62 determines that the safe operating range is exceeded, then immediately cut off the power supply to all SMA drive circuits and PI heating film; if the temperature exceeds the safe temperature threshold preset by the upper controller, then start the cooling fan for forced heat dissipation, otherwise maintain the fan as before; if it is determined that the safe operating range is not exceeded, then maintain the current operating state of the system. S64: After the temperature recovers to the safe temperature range preset in the upper controller and the abnormal information is eliminated, return to step S2; if the upper controller detects that the drive circuit current is continuously abnormal or the sensor data is missing, it is determined to be an unrecoverable hardware fault. The upper controller immediately triggers the fault lock state, cuts off all function outputs, and waits for manual reset after the hardware fault is eliminated.

7. The control method for the multi-polymer synergistic thermally controlled deformation structure according to claim 6, characterized in that, The specific methods for infrared temperature matrix acquisition and interpolation include: M11: Reads the raw two-dimensional temperature matrix data collected by the infrared thermal array sensor. The raw resolution of the raw temperature matrix is ​​32×24. M12: The original temperature matrix is ​​upsampled and interpolated using a cubic interpolation algorithm to obtain an interpolated temperature matrix with improved resolution, which is then used for subsequent K-means hot zone identification.

8. The control method for the multi-polymer synergistic thermally controlled deformation structure according to claim 7, characterized in that, The execution steps of the K-means multi-objective thermal sensing model include: M21: Set the number of clusters and initial cluster centers; using each temperature data point in the interpolated temperature matrix as a sample, set the number of clusters and initialize the cluster centers; M22: Calculate the distance between temperature data points and cluster centers; calculate the distance from each temperature data point to each cluster center separately; M23: Data point cluster allocation; each temperature data point is assigned to the cluster corresponding to the nearest cluster center, forming multiple temperature data point sets; M24: Update cluster centers; recalculate the average value of all temperature data points within each cluster and use this average value as the new cluster center for the corresponding cluster; M25: Iterative convergence judgment; Repeat steps M22 to M24 until the change in each cluster center meets the convergence condition, and the clustering is completed. M26: Target hot zone selection; Select the SMP main hot zone as the target hot zone from multiple hot zones obtained by clustering; M27: Target Temperature Calculation; Calculates the average temperature of all temperature data points within the SMP main thermal zone, and outputs the real-time temperature of the SMP target thermal zone.

9. The control method for the multi-polymer synergistic thermally controlled deformation structure according to claim 8, characterized in that, The viscoelastic temperature-dependent equivalent model is used to determine the stiffness state of an SMP cylinder, and specifically includes the following steps: M31: Obtain the real-time temperature of the target hot zone of SMP at the current moment, establish the correspondence between the relaxation modulus of SMP material and time based on the superimposed generalized Maxwell viscoelastic model, and extract the SMP relaxation time parameter in the correspondence to characterize the viscoelastic properties of SMP. M32: Using the WLF temperature-time equivalence relationship, the SMP relaxation time at different temperatures is equivalently converted to obtain the influence law of temperature on the SMP relaxation response speed. M33: Using the glass transition temperature of SMP material as the judgment threshold, the real-time temperature of the target hot zone of SMP is compared with the glass transition temperature; when the real-time temperature of the target hot zone of SMP is lower than the glass transition temperature, the SMP cylinder is determined to be in a high-stiffness glass state, suitable for lock-holding; when the real-time temperature of the target hot zone of SMP is higher than or equal to the glass transition temperature, the SMP cylinder is determined to be in a low-stiffness rubber state, suitable for SMA spring-driven deformation or shape recovery.

10. The control method for the multi-polymer synergistic thermally controlled deformation structure according to claim 9, characterized in that, The SMA thermo-coupled constitutive model is used for driving pulse parameter calculation and bending attitude evaluation, and specifically includes the following steps: M41: Obtain the current state parameters of the SMA spring, including the current temperature, martensite volume fraction, and elastic strain; M42: Based on the isotropic thermomechanical constitutive framework, the total free energy density of the SMA spring is decomposed into three parts: elastic performance density, phase transition free energy density, and pure thermal free energy density, which are calculated separately. M43: By differentiating the Helmholtz free energy with respect to elastic strain, the second Piola-Kirchhoff stress tensor is obtained, and the current stress state of the SMA spring is determined. M44: Based on the inelastic phase transition strain evolution relationship, calculate the phase transition deformation gradient rate of the SMA spring to obtain the phase transition shrinkage deformation amount; M45: Based on the current stress state and phase change shrinkage deformation, outputs the correspondence between the shrinkage driving force and deformation of the SMA spring, which is used for driving pulse parameter calculation and bending posture evaluation.

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