Multi-degree-of-freedom rope-driven snake-like manipulator with twist joint

Abstract

The application discloses a multi-degree-of-freedom rope-driven snake-shaped mechanical arm with a torsion joint, which comprises a mounting base and an arm body, the arm body comprises a plurality of arm segment units, connecting mechanisms and driving ropes, the plurality of arm segment units are sequentially connected through the connecting mechanisms at the heads and tails, and one end of each arm segment unit is connected with the driving ropes, so that the arm segment units control swing and torsion postures, and the other end of the driving ropes extends to the inside of the mounting base; the mechanical arm controls the swing and torsion of the arm segment units through the driving ropes, avoids the traditional snake-shaped mechanical arm from adopting swing and pitching linkage to switch work points, reduces the calculation amount of rope extension and retraction data, improves the reaction speed of the arm body, and realizes higher work efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mechanical arm devices, in particular to a multi-degree-of-freedom rope-driven snake-shaped mechanical arm with a torsion joint. BACKGROUND

[0002] The snake-shaped mechanical arm is a super-redundant continuous robot with multiple series joints, one end of which is fixed on the base like a traditional industrial robot, and the other end is connected to the working mechanism. Through the flexibility of the snake-shaped mechanical arm, various high-difficulty operations can be realized. Compared with traditional industrial robots, the biggest advantage of the snake-shaped mechanical arm is that it has super flexibility and can enter narrow and curved spaces for operation, and has wide application potential in fields such as construction, aerospace, nuclear energy, petroleum, national defense and natural gas.

[0003] The snake-shaped mechanical arm usually controls the movement of each joint in a rope-driven manner, and all joints are in series, which can complete most operation tasks in unstructured space, such as visual scanning, lighting, welding, assembly, picking, etc. in narrow space. For some special cases, for example, when a charging pile uses a snake-shaped mechanical arm to automatically charge a new energy vehicle, the end face of the arm end and the end face of the charging port need to be accurately aligned in the circumferential direction to ensure that the plug can smoothly enter the socket. For such scenarios, the traditional snake-shaped mechanical arm usually needs to add a rotary motor at the end as a torsion degree of freedom to realize the circumferential alignment function. However, this structure is not conducive to the realization of high weight-to-load ratio of the snake-shaped mechanical arm. In order to realize the high weight-to-load ratio of the mechanical arm, the arm body needs to only contain the actuator, and the power source is concentrated in the installation base. In addition, when two continuous operation points are located on the same circle perpendicular to the joint axis of a certain segment of the arm body, the traditional snake-shaped mechanical arm uses swing and pitch to realize the switching of the operation points, which needs to calculate the extension and contraction of at least three ropes. Even if the two operation points are far apart, it will involve the movement of more joint ropes, further increasing the time-consuming of calculation. Combined with the hysteresis effect of the motor, the operation of the snake-shaped mechanical arm will be more sluggish.

[0004] Therefore, based on the above problems, it is necessary to design a snake-shaped mechanical arm that moves with smaller self-weight and higher motion efficiency to overcome the shortcomings of the prior art. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a multi-degree-of-freedom rope-driven snake-shaped mechanical arm with a torsion joint, which solves the problems of low weight-to-load ratio and low motion efficiency of the existing snake-shaped mechanical arm, thereby overcoming the shortcomings of the prior art.

[0006] To solve the above-mentioned technical problems, the present invention discloses a multi-degree-of-freedom rope-driven serpentine robotic arm with a torsional joint, which includes a mounting base and an arm body. The tail end of the arm body is connected to the mounting base, and the head end of the arm body is connected to a working mechanism. The arm body includes multiple arm segment units, a connecting mechanism, and a drive rope. The multiple arm segment units are connected end to end by the connecting structure, and each arm segment unit is connected to one end of the drive rope to realize the swing and torsional posture control of the arm segment unit. The other end of the drive rope extends into the interior of the mounting base.

[0007] The connecting mechanism includes a connecting cap, a first bevel gear, and a second bevel gear. The connecting cap is located at the end gap of adjacent arm segment units, and one end of the connecting cap is connected to the beginning end of the arm segment unit. The other end of the connecting cap is hinged to the tail of another arm segment unit, and the adjacent arm segment unit is driven to swing by a drive rope. The second bevel gear is coaxially fixed to the middle of the connecting cap. The first bevel gear is located at the beginning end of the arm segment unit, and the axis of the first bevel gear is perpendicular to the axis of the second bevel gear. When the connecting cap is installed at the beginning end of the arm segment unit, the first bevel gear meshes with the second bevel gear. The first bevel gear is driven to rotate by the drive rope, which in turn drives the second bevel gear and the connecting cap to rotate circumferentially.

[0008] As a further improvement of the present invention, the first end of the arm segment unit is provided with a cap connecting part, which is coaxially connected with the connecting cap; the middle part of the cap connecting part is provided with a first mounting shaft and a second mounting shaft, the second mounting shaft is located at the central axis position of the cap connecting part, the first mounting shaft is located to the side of the second mounting shaft, and the axis of the first mounting shaft is perpendicular to the axis of the second mounting shaft, and the first bevel gear is mounted on the first mounting shaft; the middle part of the connecting cap is provided with a third mounting shaft with a connecting hole, the second mounting shaft is sleeved in the connecting hole of the third mounting shaft, the second bevel gear is fixedly connected to the third mounting shaft, and the first bevel gear meshes with the second bevel gear.

[0009] As a further improvement of the present invention, a first bearing is provided between the cap connecting part and the connecting cap, the inner ring of the first bearing is connected to the outer wall of the cap connecting part, and the outer ring of the first bearing is connected to the inner wall of the connecting cap, so that the arm segment unit and the connecting cap can rotate freely in the circumferential direction through the first bearing; a second bearing is provided between the connecting holes of the second mounting shaft and the third mounting shaft, the inner ring of the second bearing is connected to the second mounting shaft, and the outer ring of the second bearing is connected to the inner wall of the connecting hole of the third mounting shaft; a third bearing is provided at the shaft hole position of the first bevel gear, the inner ring of the third bearing is connected to the first mounting shaft, and the outer ring of the third bearing is connected to the shaft hole of the first bevel gear.

[0010] As a further improvement of the present application, the tail end of the arm segment unit is provided with a first pin shaft connecting seat, one end surface of the connecting rotary cap is provided with a second pin shaft connecting seat, and the first pin shaft connecting seat and the second pin shaft connecting seat are hingedly connected through a connecting pin shaft.

[0011] As an improvement of the present application, at least three driving ropes are connected to each arm segment unit, two of which are arranged in the arm segment unit and are spaced 180 degrees relative to the arm segment unit axis, one end of each of the two driving ropes is fixedly connected to the tail end position of the arm segment unit, and the other end of each of the two driving ropes is sequentially threaded through the subsequent arm segment unit and connected to the first driving mechanism in the mounting base, and the two groups of first driving mechanisms respectively drive the two driving ropes to control the swinging action of the arm segment unit; at the same time, one driving rope is arranged in the arm segment unit, one end of the driving rope is fixedly connected to the second driving mechanism in the mounting base, and the other end of the driving rope is connected to another second driving mechanism in the mounting base through the first bevel gear of the corresponding arm segment unit, and a pair of second driving mechanisms drive the same driving rope to control the torsional action of the connecting rotary cap connected to the first end of the arm segment unit.

[0012] As a further improvement of the present application, the first driving mechanism and the second driving mechanism both adopt a linear drive assembly, which includes a driving motor, a linear lead screw, a linear guide rail, and a slider, the linear lead screw is arranged inside the connecting base through a mounting seat, the linear guide rail is arranged in parallel with the linear lead screw, the driving motor is connected to one end of the linear lead screw, the slider is threadedly connected with the linear lead screw, and the linear guide rail is slidingly connected with the slider, when the driving motor drives the linear lead screw to rotate, the slider will move axially relative to the linear lead screw, thereby driving the driving rope connected to the slider to perform a pulling action.

[0013] The arm segment unit in the arm body is provided with 8 segments, the corresponding driving rope is provided with 24 ropes, the first driving mechanism is provided with 16 groups, and the second driving mechanism is provided with 16 groups.

[0014] When all the arm segment units in the arm body are located at the same axis position, the corresponding slider in the first driving mechanism is located at one half of the stroke of the linear lead screw, and the corresponding slider in the second driving mechanism is located at one half of the stroke of the linear lead screw.

[0015] The first driving mechanism and the second driving mechanism adopt a 6x6 matrix structure distribution, and four groups of positions in the middle of the 6x6 matrix structure are vacant.

[0016] The first bearing, the second bearing, and the third bearing all adopt angular contact ball bearings.

[0017] After adopting such a design, the present application at least has the following advantages:

[0018] The serpentine mechanical arm of the present application adopts an axis rotation structure instead of a universal joint structure of a conventional mechanical arm at a joint position, so as to realize the torsion of the joint and further expand the applicable environment of the mechanical arm. The mechanical arm only needs to control the torsion freedom of a certain arm segment unit to continuously perform multi-point operation on the same circumferential surface perpendicular to the arm segment unit, avoids the conventional serpentine mechanical arm to switch the operation points by swing and pitch linkage, reduces the calculation amount of the rope extension data, improves the arm body reaction speed, and realizes higher working efficiency. Meanwhile, the mechanical arm avoids the installation of a rotating motor at the end of the arm body to increase the self-weight of the arm body, so that the mechanical arm has a high load ratio. Moreover, the mechanical arm structure can cover the entire working space of a conventional serpentine mechanical arm of the same size, and has a larger working range. BRIEF DESCRIPTION OF DRAWINGS

[0019] The above is only a summary of the technical solutions of the present application. In order to more clearly understand the technical means of the present application, the present application is further described in detail below in combination with the drawings and specific embodiments.

[0020] Figure 1 is a structural schematic diagram of a multi-freedom degree rope-driven serpentine mechanical arm in an embodiment of the present application.

[0021] Figure 2 is a distribution structure schematic diagram of a driving mechanism located in the bottom layer in a mounting base of a serpentine mechanical arm in an embodiment of the present application.

[0022] Figure 3 is a structural schematic diagram of a first end of an arm segment unit in an embodiment of the present application.

[0023] Figure 4 is a structural schematic diagram of a tail end of an arm segment unit in an embodiment of the present application.

[0024] Figure 5 is a structural schematic diagram of a corresponding joint between adjacent arm segment units in an embodiment of the present application.

[0025] Figure 6 is a structural schematic diagram of a connecting screw cap in an embodiment of the present application.

[0026] Figure 7 is an assembly structure schematic diagram of a first bevel gear and a second bevel gear in an arm segment unit in an embodiment of the present application.

[0027] Figure 8 is a structural schematic diagram of a pitch (or swing) posture of a corresponding joint between arm segment units in an embodiment of the present application.

[0028] Figure 9 is a structural schematic diagram of a torsion initial posture of a corresponding joint between arm segment units in an embodiment of the present application.

[0029] Figure 10is a structure diagram of a torsion final posture of a corresponding joint between arm segment units in an embodiment of the present application.

[0030] Figure 11 is a joint coordinate system diagram of a snake-shaped mechanical arm in an embodiment of the present application.

[0031] Figure 12 is a joint coordinate system diagram of a traditional snake-shaped mechanical arm.

[0032] Figure 13 is a state diagram of a reachable space range of an end of a traditional snake-shaped mechanical arm.

[0033] Figure 14 is a state diagram of a reachable space range of an end of a snake-shaped mechanical arm in an embodiment of the present application.

[0034] Meaning of reference signs in the drawings:

[0035] 1 - mounting base; 101 - driving motor; 102 - shaft coupling; 103 - linear screw; 104 - sliding block; 105 - linear guide rail; 106 - mounting seat; 2 - arm body; 201 - arm segment unit; 202 - screw cap connecting part; 203 - first pin shaft connecting seat; 204 - first mounting shaft; 205 - second mounting shaft; 206 - connecting screw cap; 207 - third mounting shaft; 208 - second pin shaft connecting seat; 209 - connecting pin shaft; 210 - first bevel gear; 211 - second bevel gear; 212 - second bearing; 213 - first bearing; 214 - third bearing; 3 - driving rope. DETAILED DESCRIPTION

[0036] Examples of the embodiments described in the present application are shown in the drawings, wherein the same or similar reference signs represent the same or similar components or components having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application.

[0037] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", and "connecting" should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or integrally connected; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium, or can be the interconnection inside two components. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0038] Combination Figure 1As shown, the embodiment specifically discloses a multi-degree-of-freedom rope-driven snake-like mechanical arm with a torsion joint, which comprises a mounting base 1 and an arm body 2, the tail end of the arm body 2 is connected to the mounting base 1, and the head end of the arm body 2 is connected with a working mechanism; the arm body 2 comprises a plurality of arm segment units 201, a connecting mechanism and a driving rope 3, the plurality of arm segment units 201 are connected in sequence through the connecting structure at the head and tail, and each arm segment unit 201 is connected with one end of the driving rope 3, so as to realize the control of the swing and torsion posture of the arm segment unit 201, and the other end of the driving rope 3 extends to the inside of the mounting base 1. In the embodiment, the arm segment unit 201 is provided with 8 segments, and there are 8 joints between the adjacent arm segment units 201 and the mounting base 1, wherein each joint position comprises two degrees of freedom, that is, the corresponding joint can perform torsion and swing action; in the embodiment, 3 driving ropes 3 are used to control two degrees of freedom at each joint position, so that the whole arm body 2 has 16 degrees of freedom, and is jointly driven and controlled by 24 driving ropes 3, so as to realize the posture control of the arm body 2 in the mechanical arm.

[0039] In combination with Figure 3 , Figure 5 and Figure 6 As shown, the connecting mechanism in the embodiment comprises a connecting screw cap 206, a first bevel gear 210 and a second bevel gear 211, the connecting screw cap 206 is located in the gap between the end portions of the adjacent arm segment units 201, and one end of the connecting screw cap 206 is connected with the head end of the arm segment unit 201; specifically, the head end of the arm segment unit 201 is provided with a screw cap connecting portion 202, the screw cap connecting portion 202 is coaxially connected with the connecting screw cap 206, a first bearing 213 is arranged between the screw cap connecting portion 202 and the connecting screw cap 206, the inner ring of the first bearing 213 is connected with the outer wall of the screw cap connecting portion 202, and the outer ring of the first bearing 213 is connected with the inner wall of the connecting screw cap 206, so that the arm segment unit 201 and the connecting screw cap 206 are kept free to rotate circumferentially through the first bearing 213.

[0040] As Figure 5As shown, in this embodiment, to drive the adjacent arm segment units 201 to rotate, a first mounting shaft 204 and a second mounting shaft 205 are provided in the middle of the cap connecting part 202. The second mounting shaft 205 is located at the central axis of the cap connecting part 202, and the first mounting shaft 204 is located to the side of the second mounting shaft 205, with the axis of the first mounting shaft 204 perpendicular to the axis of the second mounting shaft 205. The first bevel gear 210 is located at the beginning of the arm segment unit 201. The first mounting shaft 204 is mounted on the second mounting shaft 205. The connecting cap 206 has a third mounting shaft 207 with a connecting hole in its center. The second mounting shaft 205 is sleeved in the connecting hole of the third mounting shaft 207. The second bevel gear 211 is coaxially fixed to the center of the connecting cap 206, i.e., the second bevel gear 211 is fixedly connected to the third mounting shaft 207. The axis of the first bevel gear 210 is perpendicular to the axis of the second bevel gear 211, and the first bevel gear 210 and the second bevel gear 211 are in a meshing state. Figure 7 As shown, when the connecting cap 206 is installed at the first end of the arm segment unit 201, the first bevel gear 210 and the second bevel gear 211 are meshed and connected. The first bevel gear 210 is driven to rotate by the drive rope 3, which in turn drives the second bevel gear 211 and the connected connecting cap 206 to rotate circumferentially.

[0041] A second bearing 212 is provided between the connecting holes of the second mounting shaft 205 and the third mounting shaft 207. The inner ring of the second bearing 212 is connected to the second mounting shaft 205, and the outer ring of the second bearing 212 is connected to the inner wall of the connecting hole of the third mounting shaft 207. A third bearing 214 is provided at the shaft hole position of the first bevel gear 210. The inner ring of the third bearing 214 is connected to the first mounting shaft 204, and the outer ring of the third bearing 214 is connected to the shaft hole of the first bevel gear 210. Preferably, in this embodiment, the first bearing 213, the second bearing 212, and the third bearing 214 are all angular contact ball bearings.

[0042] Combination Figure 4 and Figure 5 As shown, in this embodiment, the other end of the connecting cap 206 is hinged to the tail of another arm segment unit 201, and the adjacent arm segment unit 201 is driven to swing by the drive rope 3; specifically, the tail end of the arm segment unit 201 is provided with a first pin connecting seat 203, and one end face of the connecting cap 206 is provided with a second pin connecting seat 208. The first pin connecting seat 203 and the second pin connecting seat 208 are hinged together by a connecting pin.

[0043] More specifically, each arm segment unit 201 in the embodiment is connected with at least three driving ropes 3. In the embodiment, since the arm segment unit 201 is provided with eight segments, the corresponding driving ropes 3 in the arm body 2 are provided with at least 24 driving ropes 3. In each arm segment unit 201, two driving ropes 3 are arranged in the arm segment unit 201, and the two driving ropes 3 are spaced 180° relative to the axis of the arm segment unit 201. One end of each of the two driving ropes 3 is fixedly connected to the tail end position of the arm segment unit 201, and the other end of each of the two driving ropes 3 passes through the subsequent arm segment unit 201 and is connected to the first driving mechanism in the mounting base 1. The two groups of first driving mechanisms drive the two driving ropes 3 to control the arm segment unit 201 to swing. Meanwhile, one driving rope 3 is arranged in the arm segment unit 201, one end of the driving rope 3 is fixedly connected to the second driving mechanism in the mounting base 1, and the other end of the driving rope 3 is connected to another second driving mechanism in the mounting base 1 around the first bevel gear 210 of the corresponding arm segment unit 201. The pair of second driving mechanisms drive the same driving rope 3 to control the connecting cap 206 connected to the head end of the arm segment unit 201 to twist.

[0044] In combination Figure 2 As shown in the drawings, the first driving mechanism and the second driving mechanism in the embodiment both adopt a linear driving assembly. The linear driving assembly includes a driving motor 101, a linear lead screw 103, a linear guide rail 105, and a sliding block 104. The linear lead screw 103 is arranged inside the mounting base through a mounting seat 106. The linear guide rail 105 is arranged in parallel with the linear lead screw 103. The driving motor 101 is located at one end of the linear lead screw 103, and the driving motor 101 is drivingly connected to the linear lead screw 103 through a shaft coupling 102. The sliding block 104 is threadedly connected to the linear lead screw 103. The linear guide rail 105 is slidingly connected to the sliding block 104. When the driving motor 101 drives the linear lead screw 103 to rotate, the sliding block 104 moves axially relative to the linear lead screw 103, thereby driving the driving rope 3 connected to the sliding block 104 to pull. It should be noted that the first driving mechanism in the embodiment is provided with 16 groups, and the second driving mechanism is provided with 16 groups. The first driving mechanism and the second driving mechanism adopt a 6x6 matrix structure distribution. Four groups of positions in the middle of the 6x6 matrix structure are vacant, and the vacant positions are used to arrange the arm body 2.

[0045] In addition, for more accurate control, the position of the driving rope 3 and the sliding block 104 needs to be adjusted after installation. When all the arm segment units 201 in the arm body 2 are in the same axial position, that is, the arm body 2 is in a straight line state, the corresponding sliding block 104 in the first driving mechanism is adjusted to be located at half of the stroke of the linear lead screw 103, and the corresponding sliding block 104 in the second driving mechanism is adjusted to be located at half of the stroke of the linear lead screw 103. Through the above-mentioned adjustment of the sliding block 104 and the driving rope 3, the posture control of the arm body 2 is more accurate, and the activity range is maximum.

[0046] Specifically, in the embodiment, the implementation mode of each degree of freedom of the corresponding joint between the arm segment units 201 of the snake-shaped mechanical arm is as follows:

[0047] Firstly, in the embodiment, the pitch (or swing) degree of freedom between the units of the arm body 2 is controlled by two driving ropes 3. The fixed positions of the two driving ropes 3 are spaced 180° relative to the axis of the arm segment unit 201, and the end of the driving rope 3 is fixed to the tail end position of the arm segment unit 201. It should be noted that in the embodiment, the fixed positions of the driving rope 3 and the arm segment unit 201 are not limited to the above-mentioned manner, and the fixed positions can be set at the head end or the tail end of the arm segment unit 201, and the control force has a difference. In the embodiment, the driving motor 101 associated with the pitch (or swing) degree of freedom is controlled to rotate in forward and reverse directions. Due to the existence of the linear lead screw 103, the rotary motion of the driving motor 101 is converted into the linear reciprocating motion of the sliding block 104, which in turn pulls the corresponding driving rope 3.

[0048] For example, as shown in Figure 8 In the embodiment, the length change Δl1, Δl2 of the two driving ropes 3 controlling the pitch swing and the angle θ1 of the pitch (or swing) of the corresponding joint are related as follows:

[0049] According to the cosine theorem, we have:

[0050]

[0051]

[0052] Based on the similarity principle, we have:

[0053]

[0054]

[0055]

[0056]

[0057] Δl1=DC1+DC2-A1B1 (7)

[0058] Δl2 = A2B2 - DC1 + DC2 (8)

[0059] wherein the pitch (or swing) angle θ1 is in the range [-60°, 60°], and DC1 = DC2, DC1, DC2, A1C1 are known values, which can be obtained by measurement.

[0060] Secondly, the torsional freedom of the corresponding joint between each arm segment unit 201 in the arm body 2 in this embodiment is controlled by one driving rope 3. In this embodiment, the driving rope 3 is controlled by the driving motor 101 to pull the driving rope 3. Since the driving rope 3 is wound around the shaft end of the first bevel gear 210, the extension and contraction movement of the driving rope 3 can be converted into the rotation of the first bevel gear 210. The first bevel gear 210 and the second bevel gear 211 rotate at a speed ratio of 2:1, thereby driving the rotation of the rotary cap 206, and realizing the torsion of the joint. As shown in Figure 9 and Figure 10 As shown, the corresponding driving rope 3 extension and contraction length Δl3 and the corresponding joint torsion angle θ2 are related as follows:

[0061]

[0062] wherein the torsion angle θ2 is in the range [-180°, 180°], and the shaft end diameter of the first bevel gear 210 is l, which is a known value, which can be obtained by measurement.

[0063] The pitch (or swing) and torsion linkage of the corresponding joint of the arm segment unit 201 described above can realize the mechanical arm posture control. According to the relationship between θ1, θ2 and Δl1, Δl2, Δl3 obtained above, by controlling the 32 driving motors 101 in the installation base 1 to reverse, the shape required by the snake-shaped mechanical arm when performing different tasks can be realized.

[0064] The comparison of the motion space of the snake-shaped mechanical arm in this embodiment with that of the conventional snake-shaped mechanical arm of the same size is as follows:

[0065] The joint coordinate system established according to the snake-shaped mechanical arm in this embodiment is shown in Figure 11 The DH parameters are shown in Table 1 below. (Note: In the following table, L is the length of the arm segment unit 201)

[0066] Table 1 DH parameter table of the snake-shaped mechanical arm of the present application

[0067]

[0068]

[0069] The joint coordinate system established according to the conventional snake-shaped mechanical arm mechanical structure is shown in Figure 12 The DH parameters are shown in Table 2 below.

[0070] Table II DH parameter table of traditional snake-like manipulator

[0071]

[0072]

[0073] Based on the above-obtained kinematic formula of the twist, pitch (or swing) angle of the corresponding arm segment unit 201, and in combination with the established DH table and the joint coordinate system, the homogeneous transformation matrix of each joint of the manipulator can be solved, and the homogeneous transformation matrix of the snake-like manipulator obtained in sequence is shown in formulas 10-13. In the following formula, L is the arm barrel length, cθ represents cosθ, and sθ represents sinθ.

[0074]

[0075]

[0076]

[0077]

[0078] Referring to the above formulas 10-13, the homogeneous transformation matrix of the subsequent joint can be sequentially solved, and finally the forward kinematics expression of the snake-like manipulator is obtained. 0 T 15 :

[0079] 0 T 15 = 0 T1 1 T2 2 T3 3 T4 4 T5 5 T6 6 T7 7 T8 8 T9 9 T 10 10 T 11 11 T 12 12 T 13 13 T 14 14 T 15

[0080] Finally, the simulation software MATLAB can be used to establish the simulation of the snake-like manipulator in the embodiment, and the working space of the snake-like manipulator is solved based on the Monte Carlo method, and the comparison diagram of the working space range of the traditional snake-like manipulator and the snake-like manipulator of the embodiment is obtained, as shown in Figure 13 and 14 .

[0081] The above description is only the preferred embodiment of the present application, and is not intended to limit the present application in any form. Those skilled in the art can make some simple modifications, equivalent changes or modifications to the above disclosed technical contents, which all fall within the protection scope of the present application.

Claims

1. A multi-degree-of-freedom rope-driven serpentine robotic arm with a torsion joint, characterized in that, The device includes a mounting base and an arm. The tail end of the arm is connected to the mounting base, and the head end of the arm is connected to a working mechanism. The arm includes multiple arm segments, a connecting mechanism, and a drive rope. The multiple arm segments are connected end to end by the connecting mechanism, and each arm segment is connected to one end of the drive rope to control the swing and twisting posture of the arm segment. The other end of the drive rope extends into the mounting base. The connecting mechanism includes a connecting cap, a first bevel gear, and a second bevel gear. The connecting cap is located at the end gap of adjacent arm segment units, and one end of the connecting cap is connected to the beginning end of the arm segment unit. The other end of the connecting cap is hinged to the tail of another arm segment unit, and the adjacent arm segment unit is driven to swing by a drive rope. The second bevel gear is coaxially fixed to the middle of the connecting cap. The first bevel gear is located at the beginning end of the arm segment unit, and the axis of the first bevel gear is perpendicular to the axis of the second bevel gear. When the connecting cap is installed at the beginning end of the arm segment unit, the first bevel gear and the second bevel gear mesh with each other. The first bevel gear is driven to rotate by the drive rope, which in turn drives the second bevel gear and the connecting cap to rotate circumferentially. Each boom segment unit is connected to at least three drive ropes. Two drive ropes are threaded inside the boom segment unit and spaced 180° apart from the boom segment unit axis. One end of each drive rope is fixedly connected to the tail end of the boom segment unit, and the other end of each drive rope passes through the subsequent boom segment unit and is connected to the first drive mechanism in the mounting base. The two sets of first drive mechanisms drive the two drive ropes to control the boom segment unit to swing. At the same time, one drive rope is threaded inside the boom segment unit, and one end of the drive rope is fixedly connected to the second drive mechanism in the mounting base. The other end is wrapped around the first bevel gear of the corresponding boom segment unit and connected to another second drive mechanism in the mounting base. The pair of second drive mechanisms drive the same drive rope to control the twisting action of the connecting cap connected to the head end of the boom segment unit.

2. The multi-degree-of-freedom rope-driven serpentine robotic arm according to claim 1, characterized in that, The first end of the arm segment unit is provided with a cap connecting part, which is coaxially connected to the connecting cap; the middle part of the cap connecting part is provided with a first mounting shaft and a second mounting shaft, the second mounting shaft is located at the central axis of the cap connecting part, the first mounting shaft is located to the side of the second mounting shaft, and the axis of the first mounting shaft is perpendicular to the axis of the second mounting shaft, and the first bevel gear is mounted on the first mounting shaft; the middle part of the connecting cap is provided with a third mounting shaft with a connecting hole, the second mounting shaft is sleeved in the connecting hole of the third mounting shaft, the second bevel gear is fixedly connected to the third mounting shaft, and the first bevel gear meshes with the second bevel gear.

3. The multi-degree-of-freedom rope-driven serpentine robotic arm according to claim 2, characterized in that, A first bearing is provided between the cap connecting part and the connecting cap. The inner ring of the first bearing is connected to the outer wall of the cap connecting part, and the outer ring of the first bearing is connected to the inner wall of the connecting cap. The first bearing enables the arm segment unit and the connecting cap to rotate freely in the circumferential direction. A second bearing is provided between the connecting holes of the second mounting shaft and the third mounting shaft. The inner ring of the second bearing is connected to the second mounting shaft, and the outer ring of the second bearing is connected to the inner wall of the connecting hole of the third mounting shaft. A third bearing is provided at the shaft hole position of the first bevel gear. The inner ring of the third bearing is connected to the first mounting shaft, and the outer ring of the third bearing is connected to the shaft hole of the first bevel gear.

4. The multi-degree-of-freedom rope-driven serpentine robotic arm according to claim 1, characterized in that, The tail end of the arm segment unit is provided with a first pin connecting seat, and one end face of the connecting screw cap is provided with a second pin connecting seat. The first pin connecting seat and the second pin connecting seat are hinged together by a connecting pin.

5. The multi-degree-of-freedom rope-driven serpentine robotic arm according to claim 1, characterized in that, Both the first and second drive mechanisms employ linear drive components. Each linear drive component includes a drive motor, a linear screw, a linear guide rail, and a slider. The linear screw is mounted inside a mounting base via a mounting bracket. The linear guide rail is parallel to the linear screw. The drive motor is connected to one end of the linear screw. The slider is threadedly connected to the linear screw, and the linear guide rail is slidably connected to the slider. When the drive motor drives the linear screw to rotate, the slider will move axially relative to the linear screw, thereby causing the drive rope connected to the slider to perform a pulling action.

6. The multi-degree-of-freedom rope-driven serpentine robotic arm according to claim 1, characterized in that, The arm body has 8 arm segments, and there are 24 corresponding drive ropes. The first drive mechanism has 16 sets, and the second drive mechanism has 16 sets.

7. The multi-degree-of-freedom rope-driven serpentine robotic arm according to claim 5, characterized in that, When all arm segment units in the arm body are in the same axial position, the corresponding slider in the first drive mechanism is located at half the stroke of the linear screw; the corresponding slider in the second drive mechanism is located at half the stroke of the linear screw.

8. The multi-degree-of-freedom rope-driven serpentine robotic arm according to claim 1, characterized in that, The first drive mechanism and the second drive mechanism are distributed in a 6×6 matrix structure, and the four sets of positions located in the middle of the 6×6 matrix structure are left vacant.

9. The multi-degree-of-freedom rope-driven serpentine robotic arm according to claim 3, characterized in that, The first, second, and third bearings are all angular contact ball bearings.

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