A modular truss-type assemblable deformation mechanism

Abstract

This invention discloses a modular truss-type assemblable deformable mechanism, including a first connecting rod, a second connecting rod, a third connecting rod, a fourth connecting rod, a fifth connecting rod, a sixth connecting rod, a seventh connecting rod, an eighth connecting rod, a first connector, a second connector, a third connector, and a fourth connector. Through different combinations of these structures, E-type trusses, B-type trusses, and S-type trusses can be formed. The E-type truss is called a tension-compression truss, possessing two degrees of freedom, allowing for tension and compression in the vertical direction. The S-type truss is called a shear truss, possessing one degree of freedom, undergoing shear deformation under lateral shear force, while the height and base length of the S-type truss structure remain unchanged. The B-type truss is called a bending-deformation truss, possessing one degree of freedom. This invention allows for splicing through connectors, enabling more complex deformations, and features high load-bearing capacity, large span, easy installation, and convenient storage and transportation.

Description

Technical Field

[0001] This invention relates to the field of deformable rigid body mechanisms, and more particularly to a modular truss-type assembleable deformable mechanism. Background Technology

[0002] Many mechanical systems perform functions by changing their geometry. Controllable shape change allows mechanisms to function more effectively in various working environments or to perform multiple tasks; systems with this capability are often called adaptive or deformable mechanisms. Typical applications of deformable mechanisms include deformable aircraft wings, active aperture antennas, and deformable mirrors in optical systems. Flexible mechanisms, smart materials, and rigid mechanisms can all be used to design deformable mechanisms. Flexible mechanisms induce structural deformation and displacement through input driving forces. Due to their hingeless design, flexible mechanisms offer advantages such as simple manufacturing and assembly processes, weight savings, reduced number of parts and joints, and elimination of mechanical rebound and friction (leading to wear). Compared to the compliant mechanism of flexible mechanisms, rigid mechanisms can provide larger rotations and displacements, avoid the design complexity caused by the nonlinear relationship between the geometry and elastic behavior of flexible mechanisms, and offer advantages such as sensitive response to external loads, precise axis-drift motion, and avoidance of high stress concentration at joints. Smart materials are actuators that generate volume forces and displacements through changes in material structure. The deformation of smart materials requires changes in certain elements of the surrounding environment, such as electricity, magnetic fields, temperature, and light. Different smart materials exhibit different properties. Piezoelectric actuators are small, rigid, heavy-duty, stackable, highly linear, have low thermal coefficients, and large bandwidth, but require high voltage. Magnetostrictors are suitable for applications requiring large scale, high force, and high stiffness. Magnetostrictors have good linearity and moderate hysteresis, but require a controlled magnetic field to be provided to the embedded actuator. Temperature actuators are low-stiffness, high-displacement actuators driven by temperature. Their advantages lie in larger strain, good linearity, and simplicity. Compared to rigid mechanisms, they are slower and have higher hysteresis rates. Smart materials are often expensive and do not meet the requirements of some deformable mechanisms that require large deformation under high loads. As can be seen from the above, flexible mechanisms, smart materials, and rigid mechanisms all have their own disadvantages to varying degrees. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies by providing a modular truss-type assemblable deformable mechanism. This truss deformable mechanism features simple manufacturing and assembly processes, weight saving, reduced number of parts and joints, the ability to provide large rotation and displacement, simple design, sensitive sensing of external loads, avoidance of high stress concentration at joints, and low cost.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0005] A modular truss-type assemblable deformable mechanism, characterized in that it comprises a first connecting rod, a second connecting rod, a third connecting rod, a fourth connecting rod, a fifth connecting rod, a sixth connecting rod, a seventh connecting rod, and an eighth connecting rod. The first, second, third, and fourth connecting rods are sequentially connected end-to-end to form a quadrilateral frame. Within the quadrilateral frame, the first and second connecting rods are connected by a first connecting member, the second and third connecting rods are connected by a second connecting member, the third and fourth connecting rods are connected by a third connecting member, and the fourth connecting rod is connected to the first connecting member of two quadrilateral frames. The two ends of the fifth connecting rod are respectively connected to the first connecting members of two quadrilateral frames. The two ends of the sixth connecting rod are respectively connected to the second connecting members of two quadrilateral frames. The two ends of the seventh connecting rod are respectively connected to the third connecting members of two quadrilateral frames. The two ends of the eighth connecting rod are respectively connected to the fourth connecting members of two quadrilateral frames. The fifth, sixth, seventh, and eighth connecting rods are telescopic structures.

[0006] Furthermore, the fifth, sixth, seventh, and eighth connecting rods are curved rod structures with constant curvature. The centers of the circles containing the fifth and sixth connecting rods coincide, and the centers of the circles containing the seventh and eighth connecting rods coincide, forming a B-1 type truss structure.

[0007] Furthermore, the first and third connecting rods are telescopic curved rod structures with constant curvature. The centers of the circles containing the first and third connecting rods in the same quadrilateral frame coincide. Four ninth connecting rods are also provided. One end of each ninth connecting rod is connected to the second and fourth connecting rods through a rotating connector, and the other end is connected to each other through a cross connector.

[0008] Furthermore, the first connecting member is fixedly connected to the second connecting rod, the first connecting rod and the fifth connecting rod respectively; the second connecting member is fixedly connected to the second connecting rod, the third connecting rod and the sixth connecting rod respectively; the third connecting member is fixedly connected to the fourth connecting rod, the third connecting rod and the seventh connecting rod respectively; and the fourth connecting member is fixedly connected to the fourth connecting rod, the first connecting rod and the eighth connecting rod respectively, forming a B-2 type truss structure.

[0009] Furthermore, a first support rod and a second support rod are connected between the two quadrilateral frames. One end of the first support rod is slidably connected to the first connecting rod of one quadrilateral frame via a first sliding block, and the other end is fixedly connected to the first connecting rod of the other quadrilateral frame via a first fixing block. One end of the second support rod is slidably connected to the third connecting rod of one quadrilateral frame via a second sliding block, and the other end is fixedly connected to the third connecting rod of the other quadrilateral frame via a second fixing block, forming an S-shaped truss structure.

[0010] Furthermore, the first connecting member is fixedly connected to the first connecting rod and the second connecting rod, and rotatably connected to the fifth connecting rod; the second connecting member is fixedly connected to the second connecting rod and the third connecting rod, and rotatably connected to the sixth connecting rod; the third connecting member is fixedly connected to the third connecting rod and the fourth connecting rod, and rotatably connected to the seventh connecting rod; the fourth connecting member is fixedly connected to the fourth connecting rod and the first connecting rod, and rotatably connected to the eighth connecting rod.

[0011] Furthermore, the first and third connecting rods are telescopic structures, forming an E-type truss structure.

[0012] Compared with existing technologies, the advantages of this invention are: 1. An assemblable truss structure with different deformation modes can achieve tensile and compressive deformation, shear deformation, and bending deformation through simple assembly of connecting rods. 2. The truss deformation mechanism features simple manufacturing and assembly processes, weight saving, reduced number of parts and joints, large rotation and displacement capabilities, simple design, sensitive sensing of external loads, avoidance of high stress concentration at joints, and low cost. 3. It has processing advantages; components can be produced according to different needs. If a large truss is required with high rigidity, components can be produced separately using materials such as synthetic steel and then assembled uniformly. If a small truss is required with low rigidity, it can be manufactured using 3D printing, which is simple and convenient. 4. Multiple different types of trusses can be spliced ​​using connectors, such as hinges. These connectors are simple to process and inexpensive. 5. The connectors and trusses of the truss deformation mechanism can be driven by individual stepper motors, making it easy to program and achieve the required mechanism deformation forms. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0014] Figure 2 This is a schematic diagram of the structure of Embodiment 2 of the present invention;

[0015] Figure 3 This is a schematic diagram of the structure of Embodiment 3 of the present invention;

[0016] Figure 4 This is a schematic diagram of the structure of Embodiment 4 of the present invention;

[0017] Figure 5 A schematic diagram of the splicing structure between three E-type trusses and two S-type trusses;

[0018] Figure 6 A schematic diagram of the splicing structure of four B-2 type trusses;

[0019] Figure 7 This is a schematic diagram of the splicing structure of eight B-1 type trusses.

[0020] Wherein: 1-First connecting rod, 2-Second connecting rod, 3-Third connecting rod, 4-Fourth connecting rod, 5-Fifth connecting rod, 6-Sixth connecting rod, 7-Seventh connecting rod, 8-Eighth connecting rod, 9-Ninth connecting rod, 11-First connecting piece, 12-Second connecting piece, 13-Third connecting piece, 14-Fourth connecting piece, 15-Rotating connecting piece, 16-Cross connecting piece, 17-First support rod, 18-Second support rod, 19-First sliding block, 20-First fixed block, 21-Second sliding block, 22-Second fixed block. Detailed Implementation

[0021] To enhance understanding of the present invention, we will now describe it in further detail with reference to the accompanying drawings. These embodiments are for illustrative purposes only and do not constitute a limitation on the scope of protection of the present invention.

[0022] Example 1

[0023] Figure 1The diagram illustrates a structural schematic of Embodiment 1 of the present invention, namely the B-1 type truss. The B-1 type truss, as a type of in-plane bending deformation truss, includes two identical quadrilateral frames. Each quadrilateral frame is formed by a first connecting rod 1, a second connecting rod 2, a third connecting rod 3, and a fourth connecting rod 4 connected end-to-end in sequence. Within each quadrilateral frame, the first connecting rod 1 and the second connecting rod 2 are connected by a first connecting member 11; the second connecting rod 2 and the third connecting rod 3 are connected by a second connecting member 12; the third connecting rod 3 and the fourth connecting rod 4 are connected by a third connecting member 13; and the fourth connecting rod 4 and the first connecting rod 1 are connected by a fourth connecting member 14. The two ends of the fifth connecting rod 5 are respectively connected to the first connecting members 11 of the two quadrilateral frames; the two ends of the sixth connecting rod 6 are respectively connected to the second connecting members 12 of the two quadrilateral frames; the two ends of the seventh connecting rod 7 are respectively connected to the third connecting members 13 of the two quadrilateral frames; and the two ends of the eighth connecting rod 8 are respectively connected to the fourth connecting members 14 of the two quadrilateral frames. The fifth connecting rod 5, the sixth connecting rod 6, the seventh connecting rod 7, and the eighth connecting rod 8 are all telescopic curved rod structures using sliding pairs with constant curvature. The circles containing the fifth connecting rod 5 and the sixth connecting rod 6 are in the same plane and their centers coincide, as are the circles containing the seventh connecting rod 7 and the eighth connecting rod 8. When one of these connecting rods undergoes telescopic sliding, the remaining connecting rods also undergo the same movement; that is, the B-1 type truss structure has a single degree of freedom.

[0024] Example 2

[0025] Figure 2 The diagram shows a schematic of the structure of the B-2 type truss, which is a spatial bending variant truss. Based on the structure of the first embodiment, the B-2 type truss adds four ninth connecting rods 9. The first connecting rod 1 and the third connecting rod 3 adopt a telescopic bending rod structure with constant curvature. The circles containing the first connecting rod 1 and the third connecting rod 3 in the same quadrilateral frame are in the same plane and their centers coincide. One end of the ninth connecting rod 9 is connected to the second connecting rod 2 and the fourth connecting rod 4 through a rotating connector 15, and the other end is connected to each other through a cross connector 16.

[0026] The first connecting member 11 is welded and fixed to the second connecting rod 2, the first connecting rod 1 and the fifth connecting rod 5 respectively. The second connecting member 12 is welded and fixed to the second connecting rod 2, the third connecting rod 3 and the sixth connecting rod 6 respectively. The third connecting member 13 is welded and fixed to the fourth connecting rod 4, the third connecting rod 3 and the seventh connecting rod 7 respectively. The fourth connecting member 14 is welded and fixed to the fourth connecting rod 4, the first connecting rod 1 and the eighth connecting rod 8 respectively.

[0027] When the cross connector 16 moves along the centerline of the B-2 truss, the four identical ninth connecting rods 9 push the second connecting rod 2, the fourth connecting rod 4, the fifth connecting rod 5, the sixth connecting rod 6, the seventh connecting rod 7, and the eighth connecting rod 8, causing the B-2 truss to expand or contract as a whole.

[0028] Example 3

[0029] Figure 3 The diagram shows a schematic of the structure of an S-shaped truss according to Embodiment 3 of the present invention. The S-shaped truss is a type of shear-variant truss. Based on Embodiment 1, the structure of the S-shaped truss is improved by adding a first support rod 17 and a second support rod 18. One end of the first support rod 17 is slidably connected to the first connecting rod 1 of one quadrilateral frame through a first sliding block 19, and the other end is fixedly connected to the first connecting rod 1 of another quadrilateral frame through a first fixing block 20. One end of the second support rod 18 is slidably connected to the third connecting rod 13 of one quadrilateral frame through a second sliding block 21, and the other end is fixedly connected to the third connecting rod 13 of another quadrilateral frame through a second fixing block 22. The first connecting member 11 is fixedly welded to the first connecting rod 1 and the second connecting rod 2, and rotatably connected to the fifth connecting rod 5; the second connecting member 12 is fixedly welded to the second connecting rod 2 and the third connecting rod 3, and rotatably connected to the sixth connecting rod 6; the third connecting member 13 is fixedly welded to the third connecting rod 3 and the fourth connecting rod 4, and rotatably connected to the seventh connecting rod 7; the fourth connecting member 14 is fixedly welded to the fourth connecting rod 4 and the first connecting rod 1, and rotatably connected to the eighth connecting rod 8. The fifth connecting rod 5, the sixth connecting rod 6, the seventh connecting rod 7, and the eighth connecting rod 8 are straight rod structures.

[0030] When the S-shaped truss is subjected to a shear force parallel to the direction of the first connecting rod 1, the fifth connecting rod 5, the sixth connecting rod 6, the seventh connecting rod 7, and the eighth connecting rod 8 undergo expansion and contraction. The fifth connecting rod 5, the sixth connecting rod 6, the seventh connecting rod 7, and the eighth connecting rod 8 rotate relative to the first connecting member 11, the second connecting member 12, the third connecting member 13, and the fourth connecting member 14, respectively. At this time, the first sliding block 19 and the second sliding block 21 slide along the first connecting rod 1 and the third connecting rod 3, respectively. Under the support of the first support rod 17 and the second support rod 18, the distance between the two quadrilateral frames is determined by the length of the first support rod 17 and the second support rod 18 and does not change.

[0031] Example 4

[0032] Figure 4The diagram shows a structural schematic of the fourth embodiment of the present invention, namely the E-type truss. As a type of tension-compression truss, the E-type truss, based on the first embodiment, has the first connecting rod 1 and the third connecting rod 3 adopting a telescopic straight rod structure, while the fifth connecting rod 5, the sixth connecting rod 6, the seventh connecting rod 7 and the eighth connecting rod 8 adopt a straight rod structure.

[0033] When the first connecting rod 1 extends or retracts, the third connecting rod 3 also extends or retracts in the same way. When one of the fifth connecting rod 5, the sixth connecting rod 6, the seventh connecting rod 7, and the eighth connecting rod 8 extends or retracts, the other three rods also extend or retract in the same way.

[0034] E-type trusses, S-type trusses, B-1 type trusses, and B-2 type trusses can establish splicing between trusses by sharing members. The truss deformation mechanism can complete complex shape deformation. The truss deformation mechanism changes its own shape in a controlled manner, which can enable it to play a more effective role under various operating conditions. Figure 5-7 A schematic diagram of the composite truss is shown. Figure 5 The diagram illustrates the connection between three E-type trusses and two S-type trusses. The E-type trusses, due to the constraint of shared members, have only one degree of freedom. Figure 5 The combined truss on display resembles scaffolding, but this combined truss can be extended using E-type trusses or rotated using S-type trusses. Figure 6 The exhibition showcases the assembly of four B-2 type trusses, which can be considered part of a deployable mechanism. Deployable mechanisms have the ability to significantly reduce the volume of the vehicle when folded and are widely used in aerospace vehicles. Figure 7 The demonstration showcased the assembly of eight B-1 type composite trusses, resembling a two-jaw robotic arm. Each claw is composed of four B-1 type trusses, with one end of the truss at the bottom of each claw welded to a fixed platform. Compared to traditional robotic claws, the presence of sliding pairs greatly increases the gripping range of the robotic claws.

[0035] The truss deformation mechanism is driven by a stepper motor. The connectors and the truss are driven by separate stepper motors, and the desired deformation form of the mechanism can be easily programmed.

[0036] The above specific embodiments are only for illustrating the technical concept and structural features of the present invention, and are intended to enable those skilled in the art to implement them. However, the above content does not limit the scope of protection of the present invention. Any equivalent changes or modifications made in accordance with the spirit and essence of the present invention should fall within the scope of protection of the present invention.

Claims

1. A modular truss-type assembleable and deformable mechanism, characterized in that: The system includes a first connecting rod (1), a second connecting rod (2), a third connecting rod (3), a fourth connecting rod (4), a fifth connecting rod (5), a sixth connecting rod (6), a seventh connecting rod (7), and an eighth connecting rod (8). The first connecting rod (1), the second connecting rod (2), the third connecting rod (3), and the fourth connecting rod (4) are connected end to end to form a quadrilateral frame. Within the quadrilateral frame, the first connecting rod (1) and the second connecting rod (2) are connected by a first connecting piece (11), the second connecting rod (2) and the third connecting rod (3) are connected by a second connecting piece (12), and the third connecting rod (3) and the fourth connecting rod (4) are connected by a third connecting piece (13). The fourth connecting rod (4) and the first connecting rod (1) are connected by the fourth connecting piece (14). The two ends of the fifth connecting rod (5) are respectively connected to the first connecting piece (11) of the two quadrilateral frames. The two ends of the sixth connecting rod (6) are respectively connected to the second connecting piece (12) of the two quadrilateral frames. The two ends of the seventh connecting rod (7) are respectively connected to the third connecting piece (13) of the two quadrilateral frames. The two ends of the eighth connecting rod (8) are respectively connected to the fourth connecting piece (14) of the two quadrilateral frames. The fifth connecting rod (5), the sixth connecting rod (6), the seventh connecting rod (7) and the eighth connecting rod (8) are telescopic structures. The fifth connecting rod (5), the sixth connecting rod (6), the seventh connecting rod (7) and the eighth connecting rod (8) are curved rod structures with constant curvature. The centers of the circles where the fifth connecting rod (5) and the sixth connecting rod (6) are located coincide, and the centers of the circles where the seventh connecting rod (7) and the eighth connecting rod (8) are located coincide, forming a B-1 type truss structure. The first connecting rod (1) and the third connecting rod (3) are telescopic bent rod structures with constant curvature. The centers of the circles containing the first connecting rod (1) and the third connecting rod (3) in the same quadrilateral frame coincide. There are also four ninth connecting rods (9). One end of the ninth connecting rod (9) is connected to the second connecting rod (2) and the fourth connecting rod (4) through a rotating connector (15), and the other end is connected to each other through a cross connector (16). The first connector (11) is fixedly connected to the second connector (2), the first connector (1) and the fifth connector (5) respectively. The second connector (12) is fixedly connected to the second connector (2), the third connector (3) and the sixth connector (6) respectively. The third connector (13) is fixedly connected to the fourth connector (4), the third connector (3) and the seventh connector (7) respectively. The fourth connector (14) is fixedly connected to the fourth connector (4), the first connector (1) and the eighth connector (8) respectively, forming a B-2 type truss structure.

2. The modular truss-type assembleable deformable mechanism according to claim 1, characterized in that: A first support rod (17) and a second support rod (18) are connected between the two quadrilateral frames. One end of the first support rod (17) is slidably connected to the first connecting rod (1) of one quadrilateral frame through a first sliding block (19), and the other end is fixedly connected to the first connecting rod (1) of the other quadrilateral frame through a first fixing block (20). One end of the second support rod (18) is slidably connected to the third connecting rod (3) of one quadrilateral frame through a second sliding block (21), and the other end is fixedly connected to the third connecting rod (3) of the other quadrilateral frame through a second fixing block (22).

3. The modular truss-type assembleable deformable mechanism according to claim 2, characterized in that: The first connector (11) is fixedly connected to the first connecting rod (1) and the second connecting rod (2) respectively, and is rotatably connected to the fifth connecting rod (5); the second connector (12) is fixedly connected to the second connecting rod (2) and the third connecting rod (3) respectively, and is rotatably connected to the sixth connecting rod (6); the third connector (13) is fixedly connected to the third connecting rod (3) and the fourth connecting rod (4) respectively, and is rotatably connected to the seventh connecting rod (7); the fourth connector (14) is fixedly connected to the fourth connecting rod (4) and the first connecting rod (1) respectively, and is rotatably connected to the eighth connecting rod (8), forming an S-shaped truss structure.

4. The modular truss-type assembleable deformable mechanism according to claim 1, characterized in that: The first connecting rod (1) and the third connecting rod (3) adopt a telescopic straight rod structure, and the fifth connecting rod (5), the sixth connecting rod (6), the seventh connecting rod (7) and the eighth connecting rod (8) adopt a straight rod structure to form an E-truss structure.

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