Rigid-flexible coupling metamorphic unit and rigid-flexible coupling metamorphic mechanism

Abstract

This invention discloses a rigid-flexible coupling variable cell unit, comprising: a rotating shaft, a slider, two annular elastic elements, and m planar connecting rod sub-units, where m ≥ 2; the slider is slidably mounted on the rotating shaft; the planar connecting rod sub-units are four-bar structures connected end-to-end, including a front fixed rod, a rear fixed rod, a front hinge rod, and a rear hinge rod; one end of the front fixed rod is fixedly connected to the rotating shaft, and the other end is hinged to the front hinge rod; one end of the rear fixed rod is fixedly connected to the slider, and the other end is hinged to the rear hinge rod; the front and rear fixed rods are parallel; the front and rear hinge rods are hinged; the m front fixed rods are coplanar; the m rear fixed rods are coplanar; both the front and rear hinge rods have grooves in their middle portions, namely a front groove and a rear groove; one annular elastic element is fitted onto the m front grooves; another annular elastic element is fitted onto the m rear grooves. The present invention also discloses a rigid-flexible coupling variable cell mechanism, which includes n rigid-flexible coupling variable cell units as described above, where n≥2; the n rigid-flexible coupling variable cell units are connected end to end.

Description

Technical Field

[0001] This invention relates to a rigid-flexible coupled variable cell unit and a rigid-flexible coupled variable cell mechanism. Background Technology

[0002] Variable-cell folding mechanisms are commonly used to achieve adaptive structural changes and are widely applied in deformable structures, flexible robots, and spacecraft folding. Existing variable-cell folding mechanisms are typically based on folding and unfolding geometry, enabling the mechanism to transform its structural form under static and dynamic conditions. These technologies include folding mechanisms based on rigid folding surfaces, deformable structures based on smart materials, and dynamic folding designs utilizing certain geometric principles. Current research focuses on how to achieve efficient folding and unfolding functions through specific structural designs using limited actuation sources.

[0003] Variable cell folding mechanisms typically have the following problems:

[0004] 1. Complex control of the unfolding process: Most existing variable-cell unfolding mechanisms rely on complex mechanical drive systems, which makes it difficult to control the unfolding process. In particular, error accumulation and structural instability are likely to occur in high-precision applications.

[0005] 2. The compatibility problem between structural rigidity and flexibility: In multi-degree-of-freedom variable-cell structures, how to balance the properties of rigid and flexible materials so that the mechanism can maintain good bending and unfolding performance under load is a technical problem that urgently needs to be solved.

[0006] 3. Limited adaptability and adjustability: Existing variable-cell folding and unfolding mechanisms usually lack sufficient flexibility in terms of shape transformation and stiffness adjustment after folding or unfolding, and cannot adapt to changing working environments or load conditions.

[0007] Rigid-flexible coupled variable-cell mechanisms aim to overcome the limitations of traditional mechanisms in structural deformation, especially in terms of adaptability and flexibility under complex loads and motion conditions. This technology combines rigid and flexible materials or structural designs, enabling adaptive deformation without sacrificing overall stability, thus improving system performance under various operating conditions. This technology has wide applications in robotics, aerospace, deformable structures, and intelligent control, and holds significant technological value and application prospects, particularly in scenarios requiring high flexibility and precise control.

[0008] Therefore, providing a rigid-flexible coupling variable cell mechanism that is simple to control and highly adaptable has become a problem that the industry needs to solve. Summary of the Invention

[0009] To address the shortcomings of existing technologies, the main objective of this invention is to provide a rigid-flexible coupled variable cell unit and a rigid-flexible coupled variable cell mechanism.

[0010] To achieve the above-mentioned main objectives, on the one hand, the present invention discloses a rigid-flexible coupled variable cell unit, which includes: a rotating shaft, a slider, two annular elastic elements, and m planar connecting rod sub-units, where m≥2;

[0011] The slider is mounted on the rotating shaft.

[0012] The planar linkage subunit is a four-bar structure connected end to end, including a front fixed link (frame part), a rear fixed link (slider part), a front hinge link, and a rear hinge link; one end of the front fixed link is fixedly connected to the rotating shaft, and the other end is hinged to the front hinge link; one end of the rear fixed link is fixedly connected to the slider, and the other end is hinged to the rear hinge link; the front fixed link and the rear fixed link are parallel; the front hinge link and the rear hinge link are hinged.

[0013] m front fixed rods are coplanar; m rear fixed rods are coplanar; the middle of both the front and rear hinge rods is provided with a groove, namely the front groove and the rear groove; a ring elastic element is fitted on the m front grooves; another ring elastic element is fitted on the m rear grooves.

[0014] In this invention, a linkage-slider mechanism is used to realize the conversion of kinematic pairs from revolute pairs to prismatic pairs. The increase in the number of kinematic pairs caused by centrifugal force completes the variable topology design of the mechanism, which has efficient motion conversion, simple and reliable structure, and precise motion control.

[0015] According to one specific embodiment of the present invention, the rotating shaft is a smooth rod, and the slider is sleeved on the rotating shaft.

[0016] According to a specific embodiment of the present invention, an angle limiting mechanism is provided between the rear fixed rod and the rear hinged rod.

[0017] According to one specific embodiment of the present invention, the angle limiting mechanism is a 91° limiting mechanism.

[0018] According to one specific embodiment of the present invention, the annular elastic element is a rubber band. In this invention, the elastic force is adjusted by increasing or decreasing the number of rubber bands. It is worth noting that regardless of how many rubber bands are fitted on the m front grooves, they are all equivalent to one annular elastic element; similarly, regardless of how many rubber bands are fitted on the m rear grooves, they are all equivalent to one annular elastic element.

[0019] According to one specific embodiment of the present invention, m is an even number, and the m planar link sub-units are grouped in pairs, with the eight links of each pair of planar link sub-units being coplanar. Considering rotational inertia balance, m is set to an even number because uniform mass distribution is beneficial for stability during rotation. If the center of mass is not in the exact center, an additional torque will affect rotational stability, placing higher demands on the axis of rotation. The more planar link sub-units (an even number), the more symmetrical the mass distribution.

[0020] Considering both mass distribution and manufacturing cost, four planar link sub-units are optimal. According to one specific embodiment of the invention, m = 4; the four planar link sub-units are spaced 90° apart. Dividing the flywheel mass into two parts typically results in a symmetrical mass distribution. If the flywheel is not perfectly symmetrical or if minor manufacturing errors occur, it may generate unbalanced centrifugal forces, leading to vibration and noise, especially at high speeds. This unbalanced force may impose additional burden on the bearings, accelerating wear. Dividing the mass into four parts promotes a more uniform mass distribution, reduces manufacturing errors, and ensures symmetry.

[0021] On the other hand, the present invention provides a rigid-flexible coupling variable cell mechanism, which includes n rigid-flexible coupling variable cell units as described above, n≥2; the n rigid-flexible coupling variable cell units are connected end to end, and the n sliders are all slidably arranged on the rotating shaft and arranged in sequence; in two adjacent rigid-flexible coupling variable cell units, the rear fixed rod of the previous rigid-flexible coupling variable cell unit and the front fixed rod of the next rigid-flexible coupling variable cell unit are combined into one rod.

[0022] In this invention, two variable cell units can be combined together to achieve switching between multiple different configurations (see Example 2 for details); similarly, combining multiple variable cell units together can generate more transformation configurations. The following analyzes the combination of multiple variable cell units and the number of configurations that can be achieved.

[0023] Since the rotational speed is difficult to stabilize at a single point, a single variable cell unit cannot be stabilized in an intermediate configuration. The most convenient configurations to achieve are folded and unfolded states. Assuming that each variable cell unit has two configurations that can be adjusted with speed, and multiple variable cell units can be individually adjusted with different speeds, then the number of configurations of a variable cell mechanism composed of multiple variable cell units can be considered to be: 2. n To achieve this number of configurations, the rubber bands of the variable cell units need to be replaced. Under the operation of a multi-variable cell unit mechanism composed of individual combinations, the number of configurations that can be achieved is n+1 (the number of configurations that each variable cell unit unfolds in sequence is n, in addition to one completely folded configuration).

[0024] The main analysis focuses on the possibility of individual adjustment of multiple variable-cell units at different speeds. First, the variable-cell unit of the head is analyzed. The frame of the head's variable-cell unit is fixed, and the slider slides under the influence of the elastic band tension and the centrifugal force generated by the connecting rod. The criterion for determining the folding and unfolding of the head's variable-cell unit is as follows:

[0025] Centrifugal force of connecting rod > maximum tension of rubber band

[0026] Analyzing the middle variable cell unit, since its frame is connected to the slider of the previous variable cell unit, and the slider is connected to the frame of the next variable cell unit, the influence of both the previous and next variable cell units must be considered when analyzing the folding / unfolding behavior of the middle variable cell unit. This variable cell unit is subjected to tensile forces from two adjacent variable cell units; these are external forces. In a steady state, the two external forces cancel each other out. Therefore, the criterion for determining whether this variable cell unit folds / unfolds remains the same:

[0027] Centrifugal force of connecting rod > maximum tension of rubber band

[0028] Similarly, in a steady state, the terminal variable cell has no connection and no force at its end, therefore the terminal variable cell is not under tension. Thus, the criterion for determining whether the variable cell has unfolded in a steady state is also:

[0029] Centrifugal force of connecting rod > maximum tension of rubber band

[0030] From the above analysis, when multiple variable-cell units are combined, their unfolded state only needs to be determined by the centrifugal force on the connecting rod and the maximum tension of the rubber band. Since the multiple variable-cell units are rigidly connected, their rotational speed is the same. If the mass of the connecting rods is the same, then the centrifugal force they experience is the same. In this case, only the number of rubber bands needs to be adjusted to adjust the unfolding order of different variable-cell units. However, since the tension of each rubber band is fixed, when there are many variable-cell units, there may be situations where the centrifugal force is insufficient to overcome the tension of the rubber bands. In this case, it is only necessary to adjust the mass of the connecting rods to increase the centrifugal force to overcome the tension of the rubber bands.

[0031] Therefore, the theory of multiple variable cell unit combinations can be summarized as follows: multiple variable cell units are combined in a head-to-tail manner, and the number of configurations that can be achieved by adjusting the number of elastic bands in a combination of n variable cell units is 2. n The number of configurations that can be achieved by controlling the rotation speed of different variable cell units when the combination operates independently without adjusting the mass of the rubber band and connecting rod is n+1.

[0032] By combining rigid and flexible components, this invention enables more precise folding and unfolding processes through rotational speed adjustment, while maintaining structural stability and exhibiting greater adaptability and adjustability. In particular, thanks to the adjustment and control of the flexible components and the supporting force of the rigid components, this invention significantly outperforms traditional technologies in terms of adaptability and folding / unfolding accuracy under varying working conditions. Furthermore, through optimized geometric design and driving strategies, this invention can reduce the complexity of mechanical components and improve the efficiency and reliability of the overall folding / unfolding process while ensuring structural stability, thus having broader application prospects in fields such as deformable structures and flexible robots.

[0033] The present invention has the following beneficial effects:

[0034] 1. Simplified Control Process and Improved Precision: Existing folding and unfolding processes typically rely on complex multi-drive mechanical systems, resulting in low control precision and a tendency for error accumulation. This invention optimizes the control strategy for the folding and unfolding process by combining the collaborative work of rigid and flexible components. This allows for higher precision folding and unfolding through single-motor drive without relying on complex mechanical structures, reducing operational difficulty and improving overall performance. It achieves the effect of multiple drives from a single motor. When the rigid-flexible coupling variable cell mechanism of this invention is connected to the motor, it is equivalent to a flywheel. While it consumes energy during the folding and unfolding process, it does not affect the motor's output performance after folding and unfolding is complete, only its response speed. When the motor is connected to the variable cell unit or variable cell mechanism of this invention, other components can also be connected simultaneously for output.

[0035] 2. Optimizing the compatibility of rigid and flexible materials and enhancing stability: Existing folding mechanisms often face the problem of poor compatibility between rigid and flexible materials, leading to structural instability under high loads or complex motion conditions. Through the design of rigid-flexible coupling, this invention effectively overcomes this problem, achieving an organic combination of rigid and flexible components, with the rigid component as the motion element and the flexible component as the control element.

[0036] 3. Enhanced Adaptability and Adjustability: Existing variable-cell folding mechanisms have certain limitations in terms of adaptability and adjustability, failing to meet the needs of varying working conditions. This invention, through innovative geometric structure and drive control strategy, combines multiple variable-cell units to improve the mechanism's adaptability, working force, and workspace under different environments and loads, ensuring superior performance in practical applications.

[0037] 4. Wide Range of Applications: The rigid-flexible coupling variable-cell mechanism of this invention can be widely used in environments where motors are present and various complex drives are required. Its speed regulation feature makes it a potential candidate for practical applications in multiple fields, especially systems requiring high-precision folding and unfolding. The following are some possible applications:

[0038] (1) Adjustable aircraft: In aircraft (such as drones, deformable wing aircraft, etc.), the motors continuously run to drive the flapping or rotation of the wings. Combined with a rigid-flexible coupling variable cell mechanism, the folding and unfolding of the wings or the attitude of the aircraft can be controlled. By adjusting the speed of the motors, the flight performance can be optimized, and the continuous and stable operation of the aircraft can be achieved.

[0039] (2) Intelligent Transportation Vehicles: In scenarios such as electric vehicles, autonomous vehicles, or intelligent scooters, the motor operates continuously and, when combined with a rigid-flexible coupling variable cell mechanism, can be used to drive an adjustable vehicle body structure or power system. For example, in autonomous vehicles, the motor can be used to adjust the wheel suspension system to adapt to different road conditions.

[0040] (3) Medical rehabilitation equipment: Some medical equipment (such as adjustable rehabilitation beds, gait trainers, etc.) may require the motor to run continuously. A rigid-flexible coupling variable cell mechanism is used to deform the equipment to precisely adjust the patient's posture or movement, ensuring that the equipment works stably for a long time and helping the patient to carry out rehabilitation training.

[0041] (4) Wind power generation system: In the wind power generation system, the motor is equipped with a rigid-flexible coupling variable cell mechanism to adjust the angle (windward angle) of the wind turbine, ensuring that it always faces the most suitable direction to generate electricity. Especially when the wind speed is unstable, the motor needs to run continuously to maintain the optimal angle of the turbine.

[0042] To more clearly illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0043] Figure 1A This is a schematic diagram of the unfolded state of the rigid-flexible coupled variable cell unit in Embodiment 1;

[0044] Figure 1B This is a schematic diagram of the folded state of the rigid-flexible coupled variable cell unit in Example 1;

[0045] Figure 1C This is a simplified structural diagram of the folded state of the rigid-flexible coupled variable cell unit in Example 1;

[0046] Figure 1D This is a simplified structural diagram of the unfolded state of the rigid-flexible coupled variable cell unit in Example 1;

[0047] Figure 2A This is a force analysis diagram of a single planar link sub-unit in the non-elastic folding state in the rigid-flexible coupled variable cell unit of Example 1.

[0048] Figure 2B This is a force analysis diagram of a single planar link sub-unit in the non-elastic unfolded state in the rigid-flexible coupled variable cell unit of Example 1.

[0049] Figure 2C This is a force analysis diagram of a single planar link sub-unit in the elastic unfolding state of the rigid-flexible coupled variable cell unit of Example 1.

[0050] Figure 2D This is a force analysis diagram of a single planar link sub-unit in the rigid-flexible coupled variable cell unit of Example 1, showing the state of elastic folding.

[0051] Figure 3 This is a force analysis diagram of one configuration (E1 folding, E2 unfolding) of the rigid-flexible coupled variable cell mechanism of Example 1;

[0052] Figure 4 These are all configurations of the rigid-flexible coupled variable cell mechanism (double variable cell mechanism) of Example 2;

[0053] Figure 5 These are all configurations of the rigid-flexible coupled variable cell mechanism (quadruple variable cell mechanism) of Example 3. Detailed Implementation

[0054] Many specific details are set forth in the following description in conjunction with embodiments in order to provide a full understanding of the invention. However, it should be understood that the following embodiments and detailed descriptions are for illustrative purposes only and do not limit the scope of protection of the invention.

[0055] Example 1 (Four-plane element)

[0056] like Figures 1A-1B As shown, this embodiment provides a rigid-flexible coupled variable cell unit, which includes: a rotating shaft 1, a slider 2, two annular elastic elements (e.g., rubber bands 301 and 302), and four planar connecting rod sub-units 41, 42, 43, and 44. The slider 2 is slidably disposed on the rotating shaft 1. Specifically, the rotating shaft 1 is a smooth rod, and the slider 2 is sleeved on the rotating shaft 1.

[0057] The planar connecting rod subunit 41 is a four-bar structure connected end to end, including a front fixed rod 411, a rear fixed rod 412, a front hinge rod 413, and a rear hinge rod 414. One end of the front fixed rod 411 is fixedly connected to the rotating shaft 1 (e.g., through a coupling), and the other end is hinged to the front hinge rod 413. One end of the rear fixed rod 412 is fixedly connected to the slider 2, and the other end is hinged to the rear hinge rod 414. The front fixed rod 411 and the rear fixed rod 412 are parallel; the front hinge rod 413 and the rear hinge rod 414 are hinged. An angle limiting mechanism (e.g., a 91° limiting mechanism) is provided between the rear fixed rod 412 and the rear hinge rod 414.

[0058] The four front fixed rods of the four planar connecting rod subunits are coplanar, and the four rear fixed rods are coplanar; the front hinge rod and the rear hinge rod are provided with grooves in the middle, namely front groove 501 and rear groove 502 respectively; rubber band 301 is fitted on the four front grooves 501; rubber band 302 is fitted on the four rear grooves 502.

[0059] like Figures 1C-1DAs shown, the variable-topology unit in this embodiment consists of four planar linkage sub-units (planar linkage slider mechanisms), with the rotation axis being l1. In a single planar linkage sub-unit, the front hinge rod (link bc) is driven to rotate around point b, pushing the slider e to move outward along the l1 axis. When the rear hinge rod (link cd) moves to a position of 91° with the rear fixed rod (link de), the movement of the mechanism is restricted by a 91° limiting mechanism, thereby reducing the number of kinematic pairs and completing the variable topology design of the mechanism. These four planar linkage sub-units are combined in a spatial form, with their planes perpendicular to each other, forming a complete variable-topology unit. To achieve simultaneous driving of the four planar linkage sub-units, it is considered to connect the variable-topology unit to a motor. Through the rotation of the entire variable-topology unit, centrifugal force is generated on the front hinge rod (link bc) and the rear hinge rod (link cd) in a single planar linkage sub-unit, thereby realizing the parallel deployment action of the four planar linkage mechanisms (e.g., Figures 2A-2B (As shown).

[0060] A variable-cell unit consisting of four parallel planar linkage sub-units reduces kinematic pairs based on the law of variable topology kinematic pairs. To enhance the flexibility of this unit, flexible elements (such as rubber bands) are introduced into the designed variable-cell unit to control and regulate the mechanism's transformation process. Figures 2C-2D As shown, the rigid-flexible coupled variable cell unit, after introducing the elastic band, is held in place by the groove on the connecting rod. The unit's bc and cd connecting rods are simultaneously subjected to centrifugal force F and the tension f of the elastic band. By adjusting the relative relationship between the centrifugal force F and the tension f, the changing characteristics of the unit can be flexibly controlled: when the centrifugal force on the bc and cd connecting rods is greater than the elastic force f, the variable cell unit unfolds, and the slider is driven outwards, as shown... Figure 2C As shown in the unfolded state; when the centrifugal force F on links bc and cd is less than the elastic force f, the unit folds, and the slider contracts inward, as shown. Figure 2D As shown in the folded state.

[0061] By adjusting the number of rubber bands and the mass of the connecting rod in the variable cell unit, the centrifugal force F and the tension f of the rubber bands on the connecting rods when the variable cell unit rotates can be adjusted, thereby adjusting the rotational speed of the variable cell unit during deployment.

[0062] Example 2 (Double-celled structure)

[0063] This embodiment provides a rigid-flexible coupling variable cell mechanism, which includes two rigid-flexible coupling variable cell units E1 and E2 of Embodiment 1; the two rigid-flexible coupling variable cell units E1 and E2 are connected end to end, and the two sliders are slidably arranged on the rotating shaft and arranged in sequence; in the two rigid-flexible coupling variable cell units, the rear fixed rod of the first rigid-flexible coupling variable cell unit E1 and the front fixed rod of the second rigid-flexible coupling variable cell unit E2 are combined into one rod.

[0064] When the connecting rod mass is the same, the centrifugal force required for a variable-cell unit varies depending on the number of elastic bands it is bound with, resulting in different rotational speeds. By combining two variable-cell units and binding them with different numbers of elastic bands, it is possible to achieve a specific rotational speed where one variable-cell unit unfolds while the other remains bound. The two variable-cell units are combined end-to-end, meaning the frame portion of the latter variable-cell unit E2 is connected to the slider portion of the former variable-cell unit E1, as shown below. Figure 3 The de rod shown is the slider part of the variable cell unit E1 and also the frame part of the variable cell unit E2. Since the two parts are connected together, when the de rod of the variable cell unit E1 slides, it will also drive the variable cell unit E2 to slide.

[0065] This combined dual-cell mechanism achieves multiple motion states by changing the number of elastic bands, and the extension length can be changed by varying the mechanism's own rotational speed. In terms of displacement characteristics, the extended length of the mechanism doubles, from 34mm to 70.8mm. In terms of configuration transformation, the mechanism can remain in two configurations: the end slider can extend to either 52.4mm or 70.8mm. Due to the different number of elastic bands binding these two configurations, the rotational speeds differ significantly, yet the mechanism can stably maintain either configuration, allowing for some fluctuations in rotational speed.

[0066] Through this combination, the dual-cell mechanism of this embodiment can achieve four configurations: configuration 1, where both cell units E1 and E2 are folded; configuration 2, where both cell units E1 and E2 are unfolded; configuration 3, where cell unit E1 is folded and cell unit E2 is unfolded; and configuration 4, where cell unit E1 is unfolded and cell unit E2 is folded. Figure 4 As shown.

[0067] Example 3 (Quadruple Variable Cell Mechanism)

[0068] The difference between this embodiment and Embodiment 2 is that n = 4. That is, the rigid-flexible coupled variable cell mechanism in this embodiment includes 4 rigid-flexible coupled variable cell units of Embodiment 1.

[0069] The quadruple variable cell mechanism in this embodiment can achieve 16 configurations, with each variable cell unit achieving 5 configurations through rotational speed adjustment, such as... Figure 5 As shown, configurations 15, 14, 5, 1, and 16 are four configurations realized when unfolded in the order of variable cell units 4, 3, 2, and 1.

[0070] Although the present invention has been described above by way of embodiments, the above embodiments are only used to exemplify possible implementations of the present invention and are not intended to limit the scope of protection of the present invention. Any equivalent substitutions or changes made by those skilled in the art in accordance with the present invention should also be covered by the scope of protection defined by the claims of the present invention.

Claims

1. A rigid-flexible coupled variable cell unit, characterized in that, The rigid-flexible coupling variable cell unit includes: a rotating shaft, a slider, two annular elastic elements, and m planar connecting rod sub-units, where m ≥ 2; The slider is slidably mounted on the rotating shaft; The planar connecting rod subunit is a four-bar structure connected end to end, including a front fixed rod, a rear fixed rod, a front hinge rod, and a rear hinge rod; one end of the front fixed rod is fixedly connected to the rotating shaft, and the other end is hinged to the front hinge rod; one end of the rear fixed rod is fixedly connected to the slider, and the other end is hinged to the rear hinge rod; the front fixed rod and the rear fixed rod are parallel; the front hinge rod and the rear hinge rod are hinged. m of the front fixed rods are coplanar; m of the rear fixed rods are coplanar; both the front hinge rod and the rear hinge rod have a groove in the middle, namely a front groove and a rear groove; one of the annular elastic elements is fitted on the m of the front grooves; another of the annular elastic elements is fitted on the m of the rear grooves.

2. The rigid-flexible coupled variable cell unit according to claim 1, characterized in that, The rotating shaft is a smooth rod, and the slider is fitted onto the rotating shaft.

3. The rigid-flexible coupled variable cell unit according to claim 1, characterized in that, An angle limiting mechanism is provided between the rear fixed rod and the rear hinge rod.

4. The rigid-flexible coupled variable cell unit according to claim 3, characterized in that, The angle limiting mechanism is a 91° limiting mechanism.

5. The rigid-flexible coupled variable cell unit according to claim 1, characterized in that, The annular elastic element is a rubber band.

6. The rigid-flexible coupled variable cell unit according to claim 1, characterized in that, m is an even number, and the m planar link sub-units are grouped in pairs, with the eight links of each pair of planar link sub-units being coplanar.

7. The rigid-flexible coupled variable cell unit according to claim 6, characterized in that, m = 4; the four planar connecting rod sub-units are spaced 90° apart.

8. A rigid-flexible coupled variable-cell mechanism, characterized in that, The rigid-flexible coupling variable cell mechanism includes n rigid-flexible coupling variable cell units as described in any one of claims 1-7, where n ≥ 2; the n rigid-flexible coupling variable cell units are connected end to end, and the n sliders are all slidably disposed on the rotating shaft and arranged in sequence; in two adjacent rigid-flexible coupling variable cell units, the rear fixed rod of the preceding rigid-flexible coupling variable cell unit and the front fixed rod of the following rigid-flexible coupling variable cell unit are combined into a single rod.

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