Paper folding configuration shape memory alloy wire tensioning integral supporting self-sensing self-adaption deformable wheel

Abstract

A self-sensing self-adaptive deformable wheel tensioned and integrally supported by a paper folding configuration shape memory alloy wire belongs to the technical field of mechanical engineering and robots and is composed of a paper folding deformable module, a self-sensing module and a driving module, and the modules cooperate to realize the functions of wheel diameter dynamic adjustment, load self-sensing, terrain self-adaptive deformation and rigid-flexible coupling adjustment. The paper folding deformable module is designed based on an improved water bomb inlaid paper folding pattern, and an overlapping face, a small flexible piece and an additional face are additionally arranged to improve deformation flexibility. The self-sensing module comprises a tensegrity structure, continuous rigidity switching is achieved through pre-tightening force adjustment, and the load is monitored in real time through the strain-resistance effect of a shape memory alloy wire; and the driving module is directly driven by a radial electric push rod to realize wheel diameter change to adapt to terrains. By means of the structure-sensing-driving integrated design, the intelligent self-adaptive robot has the advantages of being light in weight, high in bearing capacity and intelligent and self-adaptive, and is suitable for complex terrain moving platforms such as deep space probe vehicles and disaster relief robots.

Description

Technical Field

[0001] The present invention relates to the field of mechanical engineering and robotics, and in particular to a self-sensing deformable wheel based on shape memory alloy (SMA), which is suitable for special mobile platforms such as deep space exploration vehicles and disaster relief robots. Background Art

[0002] With the increasing complexity of tasks such as deep space exploration, urban rescue, and polar scientific research, mobile robots have increasingly higher requirements for wheel adaptability. For example, Mars rovers need to avoid sinking in soft soil, disaster relief robots need to flexibly pass through narrow gaps in collapsed ruins, and polar vehicles need to adjust the wheel surface texture in real time to enhance the adhesion of ice and snow roads. Traditional fixed wheels cannot actively adapt to terrain changes, which seriously limits the scope of robot tasks. Therefore, the development of wheels with self-sensing and adaptive deformation capabilities has become a key technical requirement.

[0003] Existing deformable wheel technologies are mainly divided into two categories: mechanical deformable wheels, which achieve wheel diameter adjustment through mechanisms such as column cylinders and connecting rods, but have problems such as complex structure, heavy weight, and slow response; flexible material wheels, which use polylactic acid flexible materials, can adapt to terrain, but have serious insufficient load-bearing performance.

[0004] The advantages of the deformable wheel based on origami configuration design of the present invention over the traditional deformable wheel are as follows: rigid-flexible coupling design, which realizes continuous adjustable stiffness through the synergistic effect of the tensegrity skeleton and the origami unit; self-sensing function, which utilizes the strain-resistance effect of the SMA wire to monitor the load in situ and trigger deformation decisions; radial push rod drive, which directly acts on the origami structure to improve mechanical efficiency; lightweight and modular, the hot pressing molding process and the non-mechanical deformable structure can greatly reduce weight and manufacturing costs.

[0005] In general, the present invention has broad application prospects in deep space exploration, disaster relief robots, military reconnaissance and other fields. Its core innovation is the integrated design of "structure-perception-drive", which breaks through the technical bottleneck of traditional wheels. Summary of the invention

[0006] The purpose of the present invention is to provide an origami-shaped shape memory alloy wire tensegrity-supported self-sensing adaptive deformable wheel, which realizes dynamic adjustment of wheel diameter, real-time load perception and terrain adaptation functions through the geometric programmable characteristics of the origami structure and the stiffness adjustability of the tensegrity spokes, thereby significantly improving the passability, stability and intelligence level of the mobile robot in complex environments.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] An origami-shaped shape memory alloy wire tensegrity-supported self-sensing adaptive deformable wheel comprises an origami deformable module 1, a self-sensing module 2 and a driving module 3.

[0009] The origami deformable module 1 is composed of an origami structure 11 and an end cap structure 12. The origami structure 11 is designed and folded based on an improved water bomb mosaic pattern. The improved origami pattern adds overlapping surfaces 111, flexible small pieces 112 and additional surfaces 113. The overlapping surfaces 111 will overlap in pairs during the folding process to achieve edge control; the flexible small pieces 112 are distributed in the connection area between the hub and the rim, and are designed as isosceles obtuse triangles to enhance local deformation capabilities; the additional surface 113 is connected to the overlapping surface 111 to limit the movement of the overlapping surface to ensure that the end face is always a regular octagon, which is convenient for controlling the end face. The origami structure 11 uses a PVC plastic plate 116 as a rigid sheet, and the TPU hot melt adhesive 115 is compounded with the blended fabric 114 through a hot pressing process to form a rigid-flexible composite unit; the end cap structure 12 cooperates with the overlapping surface 111 of the origami structure 11 through an aluminum alloy hinge 121 to constrain the end face to be a regular octagon to prevent structural instability;

[0010] The self-sensing module 2 is composed of a tensegrity structure 21 and an axle 22. The tensegrity structure 21 is composed of an outer plate 211, a pin 212, an inner plate 213, a short shape memory alloy wire 214, a long shape memory alloy wire 215, a connecting rod 216, an inner plate rod connecting hole 217, an inner plate wire connecting hole 218, an outer plate wire connecting hole 219, and an outer plate rod connecting hole 2110. The outer plate 211 is arranged in parallel with the inner plate 213, and six connecting rods 216 are interference-fitted in the inner plate rod connecting hole 217 and the outer plate rod connecting hole 2110; the short shape memory alloy wire 214 and the long shape memory alloy wire 215 are wedged in the inner plate wire connecting hole 218 and the outer plate wire connecting hole 219 through the pin 212, forming a prestressed self-balancing network, and realizing continuous stiffness switching by dynamically adjusting the tension of the SMA wire.

[0011] The driving module 3 is composed of a radial push rod connector 31 and a radial electric push rod 32. The radial push rod connector is composed of a paddle 311, a screw 312, a cover plate 313 and a base 314. The paddle 311 is clearance-matched with the rigid sheet of the PVC plastic plate 116 of the origami structure 11 (H7 / g6). The base 314 is connected to the radial electric push rod 32 through the base thread. The radial electric push rod 32 is bonded to the tensegrity structure 21 through an adhesive, and the tensegrity structure 21 is fixed to the four surfaces of the wheel shaft 22 in the same way.

[0012] The working process of the present invention is as follows:

[0013] (1) Load sensing and signal transmission: The external load is transmitted to the origami structure 11 through the wheel surface, and then transmitted to the radial electric push rod 32 through the radial push rod connector 31 to act on the tensegrity structure 21, causing the short shape memory alloy wire 214 and the long shape memory alloy wire 215 to be strained; the resistance change signal of the short shape memory alloy wire 214 and the long shape memory alloy wire 215 is transmitted to the control circuit module through the bus, and the main control chip identifies the terrain type (such as rugged, flat or soft road surface) through frequency domain feature analysis.

[0014] (2) Terrain adaptive deformation: In the rugged mode, the main control triggers the radial electric push rod 31 to extend, pushing the origami structure 11 to expand to the maximum wheel diameter, increasing the wheel surface curvature and improving the obstacle crossing ability; in the flat mode, the main control triggers the electric push rod 31 to retract, the origami structure 11 shrinks to the minimum wheel diameter, and the wheel surface presents a serrated texture to enhance the grip. During the deformation process, the end cover structure 12 constrains the overlapping surface 111 through the aluminum alloy hinge 121 to ensure the geometric stability of the end surface during the deformation process.

[0015] (3) Rigid-flexible coupling adjustment: In high-rigidity mode, the tension of the short shape memory alloy wire 214 and the long shape memory alloy wire 215 is increased to the maximum, the diameter of the origami structure 11 changes to the minimum, close to the locked state, and the overall rigidity of the wheel is maximized; in high-flexibility mode, the tension of the short shape memory alloy wire 214 and the long shape memory alloy wire 215 is reduced to the minimum, the diameter of the origami structure 11 changes to the maximum, allowing the origami unit to deform locally to absorb impact energy, and the overall flexibility of the wheel is maximized. The rigid-flexible coupling is a technical effect, which is formed by the rigid PVC plastic plate 116 and the flexible TPU hot melt adhesive 115, that is, the rigid part provides support and the flexible part absorbs impact.

[0016] The advantages of the present invention are:

[0017] (1) Structural innovation: The tensegrity-origami composite configuration breaks through the load-bearing-flexibility contradiction of traditional wheels; the improved water bomb pattern and end cover structure 12 are designed to avoid structural instability during the folding process.

[0018] (2) Self-sensing function: In-situ load monitoring is achieved by utilizing the strain-resistance effect of the short shape memory alloy wire 214 and the long shape memory alloy wire 215; the stiffness is supported to be switched steplessly through dynamic adjustment of the preload force to adapt to the requirements of various terrains.

[0019] (3) High-efficiency drive: The radial electric push rod 31 directly acts on the origami structure 11, which greatly improves the efficiency compared with the traditional axial drive; the "1 push rod-2 origami units" staggered layout reduces the number of actuators and reduces energy consumption.

[0020] (4) Lightweight and reliability: The origami unit 11 prepared by the hot pressing process can greatly reduce the weight of the wheel; the radially arranged electric push rod can ensure the load-bearing capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is the overall assembly diagram of the wheel of the present invention;

[0022] Figure 2 The figure is a whole assembly diagram of the wheel of the present invention (section view);

[0023] Figure 3 The improved origami pattern of the present invention;

[0024] Figure 4 The improved origami structure of the present invention;

[0025] Figure 5 The invention provides a process for preparing an origami structure;

[0026] Figure 6 A three-dimensional model of the tensegrity structure of the present invention;

[0027] Figure 7 An exploded view of a three-dimensional model of a tensegrity structure of the present invention;

[0028] Figure 8 A three-dimensional model of the radial push rod connector structure of the present invention;

[0029] Fig. 9 It is a schematic diagram of a deformation of the present invention.

[0030] Among them: 1. Origami deformable module 11. Origami structure 12. End cover structure 111. Overlapping surface 112. Flexible small piece 113. Additional surface 114. Blended fabric 115. TPU hot melt adhesive 116. PVC plastic plate 121. Aluminum alloy hinge 122. Bolt 123. Nut 124. Cover body 2. Self-sensing module 21. Tensile integral structure 22. Axle 211. Outer plate 212. Pin 213. Inner plate 214. Short shape memory alloy wire 215. Long shape memory alloy wire 216. Connecting rod 217. Inner plate rod connecting hole 218. Inner plate wire connecting hole 219. Outer plate wire connecting hole 2110. Outer plate rod connecting hole 3. Driving module 31. Radial push rod connector 32. Radial electric push rod 311. Paddle 312. Screw 313. Cover plate 314. Base DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the accompanying drawings:

[0032] like Figure 1The origami deformable module 1 is composed of an origami structure 11 and an end cover structure 12. The origami structure 11 and the end cover structure 12 are connected by an aluminum alloy hinge 121, which is fixed on the overlapping surface 111 of the origami structure 11 by bolts 122 and nuts 123.

[0033] like Figure 2 As shown, from top to bottom, the paddle 311 is clearance-matched with the rigid sheet of the PVC plastic plate 116 of the origami structure 11 (H7 / g6), the base 314 is connected to the radial electric push rod 32 via the base thread, the radial electric push rod 32 is bonded to the tensegrity structure 21 via an adhesive, and the tensegrity structure 21 is fixed to the four surfaces of the axle 22 in the same way.

[0034] like Figure 3 , Figure 4 As shown, the structure of the origami structure 11 is based on the improved water bomb mosaic origami pattern design, and an overlapping surface 111, a flexible small piece 112, and an additional surface 113 are added. The unit pattern length of the origami pattern can be freely selected according to one's own needs; the flexible small piece 112 is distributed in the connection area between the hub and the rim, and adopts an isosceles obtuse triangle design; the additional surface 113 is formed by splicing two identical right triangles; the overlapping surface 111 is composed of two identical isosceles triangles.

[0035] like Figure 5 As shown, the origami structure 11 is prepared by using a composite layer of a blended fabric 114 and a TPU hot melt adhesive 115, and a PVC plastic plate 116 is wrapped by a hot pressing molding process to form a rigid-flexible coupling structure.

[0036] like Figure 6 , Figure 7 As shown, the assembly steps of the tensioned integral structure 21 are as follows: the inner plate 213 and the outer plate 211 are interference fit in the inner plate rod connecting hole 217 and the outer plate rod connecting hole 2110 through 6 connecting rods 216 to form a parallel rod type skeleton, and 8 long shape memory alloy wires 215 and short shape memory alloy wires 214 are wedged and fixed in the inner plate wire connecting hole 218 and the outer plate wire connecting hole 219 through pins 212 to form a prestressed tensioning network.

[0037] like Figure 8 As shown, the paddle 311 of the connector 31 has a clearance fit (H7 / g6) with the PVC plastic plate 116 in the hub area of ​​the origami structure 11, allowing an assembly error of ±2°; the tail cylinder of the paddle 311 is coaxially matched with the cylindrical groove formed by the cover plate 313 and the base 314; the base 314 is fixedly connected to the cover plate 313 by screws 312; the base 314 is connected to the radial electric push rod 32 by the thread at its tail;

[0038] like Fig. 9As shown, the diameter of the origami structure 11 increases after deformation, and the end cover structure 12 restricts the end surface to always remain a regular octagon with a constant side length.

[0039] The present invention realizes adaptive deformation and real-time status monitoring of wheels through the collaborative design of the geometric programming characteristics of the origami structure and the tensegrity-SMA sensing architecture, and is suitable for mobile platforms in complex terrains such as Mars exploration rovers and disaster relief robots.

Claims

1. An origami-shaped shape memory alloy wire tensegrity-supported self-sensing adaptive deformable wheel, characterized in that: It consists of an origami deformable module (1), a self-sensing module (2) and a driving module (3), and each module cooperates to realize terrain adaptive deformation and rigid-flexible coupling adjustment functions.

2. The wheel according to claim 1, characterized in that The origami deformable module (1) comprises an origami structure (11) and an end cover structure (12); the drive module (3) comprises a radial push rod connector (31) and a radial electric push rod (32); the origami structure (11) is a rigid-flexible coupling body, formed by a composite of a rigid PVC plastic plate (116) and a flexible TPU hot melt adhesive (115); the end cover structure (12) constrains the end surface stability of the origami structure (11) through an aluminum alloy hinge (121); the terrain adaptive deformation function achieved by the linkage of the origami deformable module (1) and the drive module (3) of the wheel comprises: in a rugged mode, the radial electric push rod (32) extends to push the origami structure (11) to expand to the maximum wheel diameter, the wheel surface curvature increases, and the obstacle crossing capability is improved; in a flat mode, the radial electric push rod (32) retracts, the origami structure (11) shrinks to the minimum wheel diameter, the wheel surface presents a serrated texture, and the grip is enhanced.

3. The wheel according to claim 1, characterized in that The self-sensing module (2) comprises a tensegrity structure (21) and a wheel axle (22); the tensegrity structure (21) comprises an outer plate (211), an inner plate (213), a connecting rod (216), a long shape memory alloy wire (215) and a short shape memory alloy wire (214), forming a prestressed tension network, and utilizing the strain-resistance effect of the shape memory alloy wire to monitor the load in real time; the rigid-flexible coupling adjustment function realized by the linkage of the self-sensing module (2) and the origami deformable module (1) of the wheel comprises: in a high rigidity mode, the tension of the short shape memory alloy wire (214) and the long shape memory alloy wire (215) is increased to a maximum, the diameter of the origami structure (11) is changed to a minimum, close to a locked state, and the overall rigidity of the wheel is maximized; in a high flexibility mode, the tension of the short shape memory alloy wire (214) and the long shape memory alloy wire (215) is reduced to a minimum, the diameter of the origami structure (11) is changed to a maximum, allowing the origami unit to deform locally to absorb impact energy, and the overall flexibility of the wheel is maximized.

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