Tendon-roped artificial muscle with force displacement self-sensing function and preparation method

Abstract

The present application belongs to the technical field of motor-driven tendon artificial muscle, and particularly relates to a tendon artificial muscle with force displacement self-sensing function and a preparation method. The tendon artificial muscle comprises a skeletal fixation plate, a torque sensing unit, an internal support platform, a shell, a motor or joint module, a winding wheel, a tendon, an output guide structure, an end connecting mechanism and a control and collection unit. The present application realizes self-sensing of artificial muscle output tension, is conducive to realizing self-sensing of artificial muscle displacement, is compatible with two output forms of circular tendon and belt-shaped tendon, can improve the winding tolerance of the tendon, improve the winding stability, and reduce the risk of winding the outer tendon into the gap of the inner tendon; the present application can further obtain equivalent stiffness, load state, slip state, overload state or fracture state according to the output tension and output displacement change relationship, and provide feedback for safety control of humanoid robots and exoskeletons.

Description

Technical Field

[0001] This invention relates to the field of motor-driven tendon-and-wire artificial muscle technology, specifically to a tendon-and-wire artificial muscle with force displacement self-sensing function and its preparation method. Background Technology

[0002] Artificial muscles are a class of biomimetic actuators used to mimic the contraction, elongation, or mechanical output of biological muscles. They are widely used in humanoid robots, exoskeleton robots, rehabilitation robots, robotic arms, and biomimetic joint drive systems. Existing forms of artificial muscles include pneumatic artificial muscles, hydraulic artificial muscles, thermally driven fiber artificial muscles, electroactive polymer artificial muscles, dielectric elastomer actuators, and rope-driven or tendon-wire-driven actuators.

[0003] For the lower limb joints of humanoid robots, especially the hip joint drive system, the actuator not only needs to have a large output force and a high response speed, but also needs to have a compact structure, stable force transmission, reliable cable delivery, and real-time status perception capabilities. Traditional chord actuation devices typically use a motor to drive a winding wheel to wind a rope or flexible tendon, thereby generating tension and displacement output. However, traditional chord actuation devices still have shortcomings in output force perception, displacement perception, and stable chord delivery.

[0004] On the one hand, traditional chord drive devices mostly rely on external tension sensors to detect output force, resulting in increased structural size, complex installation, difficult wiring, and difficulty in integration into space-constrained areas such as the hip of humanoid robots. Some systems use motor current to estimate output force, but motor current is easily affected by factors such as reducer efficiency, friction, temperature rise, inertial load, and chord slippage, making it difficult to accurately reflect the actual output tension of the chord.

[0005] On the other hand, circular tendon cords and band tendon cords differ in cross-sectional shape, winding stability, exit method, and friction and wear characteristics. Circular tendon cords are suitable for output through round holes, guide eyes, or wear-resistant bushings, while band tendon cords need to avoid folding, flipping, lateral deviation, and edge wear. Therefore, existing structures are difficult to be compatible with both circular and band tendon cords simultaneously.

[0006] Furthermore, the stability of the winding reel in taking up and releasing the line directly affects the accuracy of the artificial muscle's output displacement and its lifespan. If the winding reel's structure is not designed properly, problems such as tendon cord stacking, cord tangling, outer tendon cords getting caught in inner gaps, and unstable line output direction can easily occur.

[0007] Therefore, it is necessary to propose a new motor-driven tendon-type artificial muscle that can achieve self-sensing of output force through reaction torque measurement, self-sensing of output displacement through motor encoder, and adapt to both circular tendon and band tendon output forms, while improving the winding stability of the winding wheel and the reliability of output guidance. Summary of the Invention

[0008] The purpose of this section is to outline some aspects of the embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0009] To address the aforementioned technical problems, according to one aspect of the present invention, the present invention provides the following technical solution:

[0010] A chord-type artificial muscle with force and displacement self-sensing function includes a skeletal fixation plate, a torque sensing unit, an internal support platform, a shell, a motor or joint module, a winding wheel, a tendon ligament, an output guide structure, an end connection mechanism, and a control and acquisition unit. The first end face connection of the torque sensing unit is connected to the skeletal fixation plate, and the second end face connection of the torque sensing unit is connected to the internal support platform. The shell is fixedly sleeved on the outside of the internal support platform. The motor or joint module is disposed inside the shell, and the end fixing hole of the motor or joint module is fixed to the lower surface connection hole of the shell via a threaded connection, and the motor or joint module is not directly connected to the skeletal fixation plate. The winding wheel is fixed to the motor... On the output end face of the motor or joint module, a device is used for winding or releasing the tendon rope; one end of the tendon rope is connected to a winding wheel, and the other end is led out through an output guide structure and connected to an end connection mechanism; the control and acquisition unit is connected to a torque sensing unit and a motor or joint module; the reaction torque generated when the motor or joint module drives the winding wheel to wind or release the tendon rope is transmitted to the torque sensing unit through the end fixing hole of the motor or joint module, the outer shell, and the internal support platform; the control and acquisition unit obtains the output tension of the tendon rope based on the reaction torque detected by the torque sensing unit and the equivalent winding radius of the winding wheel, and obtains the output displacement of the tendon rope based on the output angle of the motor or joint module and the equivalent winding radius of the winding wheel.

[0011] As a preferred embodiment of the tendon-type artificial muscle with force displacement self-sensing function described in this invention, the torque sensing unit is a ring-shaped static torque sensor, which includes a ring-shaped elastomer, a first end face connection part, a second end face connection part, a strain-sensitive element, a signal conditioning circuit, and a signal lead-out part; the strain-sensitive element is used to detect the elastic deformation of the ring-shaped elastomer under the action of reaction torque.

[0012] As a preferred embodiment of the tendon-type artificial muscle with force displacement self-sensing function described in this invention, the first end face connection part and the second end face connection part of the torque sensing unit are respectively connected to the bone fixation plate and the internal support platform by fasteners. The internal support platform is connected to the outer shell by fasteners. The end fixing hole of the motor or joint module is connected to the lower surface connection hole of the lower surface of the outer shell by fasteners. The winding wheel is connected to the output end face of the motor or joint module by fasteners.

[0013] The internal support platform is provided with multiple mounting holes in its circumference, and the outer shell is provided with side surface connection holes corresponding to the mounting holes. The internal support platform and the outer shell are fixedly connected by fasteners passing through the mounting holes and side surface connection holes.

[0014] The inner surface of the housing is provided with multiple lower surface connection holes, fixing ring grooves or connecting bosses for fixing the motor or joint module. The motor or joint module is fixedly connected to the lower surface connection holes, fixing ring grooves or connecting bosses of the housing through its end fixing holes.

[0015] As a preferred embodiment of the tendon-type artificial muscle with force displacement self-sensing function described in this invention, the winding wheel includes a first winding wheel and a second winding wheel. The first winding wheel is used to adapt to the circular tendon rope, and the second winding wheel is used to adapt to the band-shaped tendon rope. The wheel height, winding groove width, or flange spacing of the second winding wheel is greater than that of the first winding wheel.

[0016] The first winding wheel is provided with a narrow groove winding section, which is one of a U-shaped groove, a V-shaped groove, a semi-circular groove, an annular groove or a spiral groove, used to limit the displacement of the circular tendon rope during the winding process;

[0017] The second winding wheel is provided with a wide groove winding section, a lateral limiting stop, and a rounded transition wire exit section, which are used to make the band tendon rope be wound flat in the width direction and to limit the lateral deviation of the band tendon rope.

[0018] As a preferred embodiment of the tendon-type artificial muscle with force displacement self-sensing function described in this invention, the winding wheel is provided with a trumpet-shaped winding structure. The trumpet-shaped winding structure is set with the outer width and the inner width along the direction in which the tendon enters the winding wheel, so as to guide the tendon to enter the winding area stably and limit the outer tendon to be wound into the gap of the inner tendon.

[0019] The trumpet-shaped winding structure includes an outer guide area and an inner limiting area. The opening width of the outer guide area is greater than the width of the inner limiting area. The outer guide area is used to improve the tolerance of tendon cord entry, and the inner limiting area is used to limit the interlayer displacement of tendon cord winding.

[0020] As a preferred embodiment of the tendon-type artificial muscle with force displacement self-sensing function described in this invention, when the tendon is a circular tendon, the output guide structure includes a first lead-out boss disposed on the outer shell, the first lead-out boss having a circular guide hole, and a wear-resistant guide bushing installed in the circular guide hole; the wear-resistant guide bushing is one of tungsten carbide guide eye, hard alloy guide bushing, ceramic guide bushing, zirconium oxide guide bushing, or low-friction polymer guide bushing.

[0021] As a preferred embodiment of the tendon-type artificial muscle with force displacement self-sensing function described in this invention, when the tendon is a band-shaped tendon, the output guide structure includes a second lead-out boss disposed on the outer shell, and a pair of columnar guide members are installed on the second lead-out boss. A band-shaped tendon guide gap is formed between the two columnar guide members, and the band-shaped tendon is led out through the band-shaped tendon guide gap to limit the lateral displacement and overturning of the band-shaped tendon.

[0022] As a preferred embodiment of the tendon-type artificial muscle with force displacement self-sensing function described in this invention, the control and acquisition unit is further used to acquire the working current of the motor or joint module, and obtain an auxiliary torque estimate based on the working current. The auxiliary torque estimate is used to verify, compensate, or determine the anomaly of the reaction torque detected by the torque sensing unit. The control and acquisition unit obtains the equivalent stiffness, load state, slippage state, overload state, or breakage state of the artificial muscle based on the relationship between the tendon output tension and the tendon output displacement.

[0023] A method for preparing a tendon-type artificial muscle with force displacement self-sensing function includes the following steps:

[0024] S1, prepare or select a bone fixation plate, torque sensing unit, internal support platform, shell, motor or joint module, winding wheel, tendon rope, output guide structure, end connection mechanism and control and acquisition unit;

[0025] S2, connect the first end face of the torque sensing unit to the bone fixation plate;

[0026] S3 connects the internal support platform to the second end face connection of the torque sensing unit;

[0027] S4, fit the outer shell onto the outside of the inner support platform and fix the outer shell to the inner support platform;

[0028] S5, assemble the motor or joint module into the housing, and fix the end fixing hole of the motor or joint module to the lower surface connection hole of the housing by thread;

[0029] S6, mount the winding wheel to the output end face of the motor or joint module;

[0030] S7, fix one end of the tendon rope to the winding wheel, and lead the other end out through the output guide structure and connect it to the end connection mechanism;

[0031] S8 applies pretension to the tendon ligament and completes the calibration of the zero torque point and zero displacement point;

[0032] S9, establish the mapping relationship between reaction torque, equivalent winding radius of the winding wheel and tendon cable output tension;

[0033] S10, establish the mapping relationship between the output angle of the motor or joint module, the equivalent winding radius of the winding wheel and the output displacement of the tendon rope;

[0034] S11, The mapping relationship or calibration parameters are written into the control and acquisition unit so that the artificial muscle can realize self-sensing of output tension and output displacement during the working process.

[0035] As a preferred embodiment of the method for preparing a tendon-type artificial muscle with force displacement self-sensing function according to the present invention, when the tendon is a circular tendon, a first winding wheel and a first lead-out boss with a wear-resistant guide bushing are selected; when the tendon is a strip-shaped tendon, a second winding wheel and a second lead-out boss with paired columnar guide members are selected.

[0036] Compared with existing technologies, the advantages of this invention are as follows: This invention allows the motor or joint module to be indirectly supported on the bone fixation plate via a shell, internal support platform, and torque sensing unit, rather than directly connected to the bone fixation plate. This enables the reaction torque generated when the motor drives the tendon cable to be detected by the torque sensing unit, thereby achieving self-sensing of the artificial muscle's output tension. This invention utilizes the encoder of the motor or joint module itself to obtain the output angle, and combines this with the equivalent winding radius of the winding wheel to obtain the tendon cable's output displacement, which is beneficial for achieving self-sensing of artificial muscle displacement. This invention is compatible with round tendon cables and straps. The invention offers two output forms of tendon cords: a circular tendon cord version using a wear-resistant guide bushing, and a strip tendon cord version using a double-column guide to form a guide gap, thereby improving the output stability of the tendon cord. The winding reel of this invention can be configured with a trumpet-shaped outer wide and inner narrow winding structure, which can improve the tendon cord infeed tolerance, improve winding stability, and reduce the risk of the outer tendon cord getting caught in the gap of the inner tendon cord. Furthermore, this invention can obtain equivalent stiffness, load state, slippage state, overload state, or fracture state based on the relationship between output tension and output displacement, providing feedback for the safety control of humanoid robots and exoskeletons. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and detailed embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0038] Figure 1 This is a schematic diagram of a circular tendon ligament version of the artificial muscle with force displacement self-sensing function according to the present invention.

[0039] Figure 2 This is a schematic diagram of the band tendon version of a tendon-type artificial muscle with force displacement self-sensing function according to the present invention.

[0040] Figure 3 This is an exploded view of the structure of a tendon-type artificial muscle with force displacement self-sensing function according to the present invention.

[0041] Figure 4 This is a diagram showing the connection structure of the torque sensing unit and internal support platform of a tendon-type artificial muscle with force displacement self-sensing function according to the present invention.

[0042] Figure 5 This is a schematic diagram of the torque sensing unit structure of a tendon-type artificial muscle with force displacement self-sensing function according to the present invention.

[0043] Figure 6 This is a schematic diagram of the internal support platform structure of a tendon-type artificial muscle with force displacement self-sensing function according to the present invention.

[0044] Figure 7 This is a schematic diagram of a circular tendon cord output guide structure for a tendon cord type artificial muscle with force displacement self-sensing function according to the present invention.

[0045] Figure 8 This is a schematic diagram of a band tendon output guide structure for a tendon-type artificial muscle with force displacement self-sensing function according to the present invention.

[0046] Figure 9 This is a schematic diagram of the first winding wheel structure of a tendon-type artificial muscle with force displacement self-sensing function according to the present invention.

[0047] Figure 10 This is a schematic diagram of the second winding wheel and the trumpet-shaped winding structure of a tendon-type artificial muscle with force displacement self-sensing function according to the present invention.

[0048] Figure 11 This is a schematic diagram illustrating the principle of force displacement self-sensing control and acquisition of a tendon-type artificial muscle with force displacement self-sensing function according to the present invention.

[0049] In the diagram: 1. Skeletal fixation plate; 2. Torque sensing unit; 21. First end face connection; 22. Second end face connection; 3. Internal support platform; 31. Mounting hole; 4. Housing; 41. Lower surface of housing; 42. Lower surface connection hole; 43. Side surface connection hole; 44. First cable exit boss; 45. Second cable exit boss; 5. Motor or joint module; 51. End fixing hole; 52. Output end face; 6. Winding reel; 61. First winding reel 611. Narrow-slot winding section; 62. Second winding wheel; 621. Wide-slot winding section; 622. Lateral limiting stop; 623. Rounded corner transition wire exit section; 63. Trumpet-shaped winding structure; 631. Outer guide area; 632. Inner limiting area; 7. Circular tendon rope; 71. Strip tendon rope; 8. Output guide structure; 81. Circular guide hole; 82. Wear-resistant guide bushing; 83. Columnar guide component; 84. Strip tendon rope guide gap; 9. Fastener. Detailed Implementation

[0050] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0051] Secondly, the present invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not according to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In addition, actual fabrication should include three-dimensional spatial dimensions of length, width, and depth.

[0052] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0053] This invention provides a tendon-type artificial muscle with force displacement self-sensing function, comprising:

[0054] Overall structure of artificial muscle: such as Figures 1 to 3 and Figure 5 As shown, it includes a bone fixation plate 1, a torque sensing unit 2, an internal support platform 3, a shell 4, a motor or joint module 5, a winding wheel 6, a circular tendon rope 7, and an output guide structure 8.

[0055] The skeleton fixation plate 1 is used to simulate the fixed end of the pelvis, the fixed end of the robot skeleton, or the installation end of the exoskeleton. The first end of the torque sensing unit 2 is connected to the skeleton fixation plate 1, and the second end of the torque sensing unit 2 is connected to the internal support platform 3. The internal support platform 3 is used to connect the outer shell 4 and support the internal structure of the actuator. The outer shell 4 is fitted onto the outside of the internal support platform 3 and is connected to the internal support platform 3 by fasteners 9.

[0056] The motor or joint module 5 is housed inside the housing 4. The end fixing hole 51 of the motor or joint module 5 is fixed to the lower surface 41 of the housing 4 via a threaded connection, thus fixing the housing portion of the motor or joint module 5 inside the housing 4. The motor or joint module 5 is not directly connected to the bone fixation plate 1. The winding wheel 6 is located on the output end face 52 of the motor or joint module 5 and is fixedly connected to the output end face 52.

[0057] One end of the circular tendon rope 7 is connected to the winding reel 6, and the other end is led out through the output guide structure 8 for connection to external loads, robot joints, hip joints, skeletal structures, or mechanical testing platforms.

[0058] The control and acquisition unit can be a host computer, industrial computer, microcontroller, internal processing unit of motor driver, data acquisition module, motion control card, PLC, or a combination thereof. The control and acquisition unit is not limited to being installed inside the artificial muscle body, but can also be externally connected to the artificial muscle body.

[0059] The control and acquisition unit is communicatively connected to the torque sensing unit 2, the encoder, motor driver and / or current acquisition module of the motor or joint module 5, respectively, and is used to receive the reaction torque signal output by the torque sensing unit, the encoder angle signal output by the motor or joint module 5 and the motor operating current signal.

[0060] The control and acquisition unit calculates the tendon cable output tension based on the reaction torque detected by the torque sensing unit 2 and the equivalent winding radius of the winding wheel 6, calculates the tendon cable output displacement based on the output angle of the motor or joint module 5 and the equivalent winding radius of the winding wheel 6, and judges the load state, slippage state, overload state or breakage state of the artificial muscle based on the tendon cable output tension, tendon cable output displacement and motor operating current.

[0061] Reaction torque measurement structure: such as Figure 1 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 11 As shown, the torque sensing unit 2 is disposed between the skeletal fixation plate 1 and the internal support platform 3. The motor or joint module 5 is not directly fixed to the skeletal fixation plate 1, but is connected to the outer shell 4 through the end fixing hole 51. The outer shell 4 is connected to the internal support platform 3, and the internal support platform 3 is connected to the skeletal fixation plate 1 via the torque sensing unit 2.

[0062] When the output end face 52 of the motor or joint module 5 drives the winding wheel 6 to wind the tendon rope, the output tension of the tendon rope generates a reaction torque on the winding wheel 6. This reaction torque is transmitted to the housing 4 through the end fixing hole 51 of the motor or joint module 5, then to the internal support platform 3 through the housing 4, and finally to the torque sensing unit 2. The torque sensing unit 2 detects the reaction torque and outputs a torque signal.

[0063] The control and acquisition unit calculates the output tension of the tendon rope based on the torque signal and the equivalent winding radius of the winding wheel 6. In one embodiment, the output tension F of the tendon rope satisfies:

[0064] F=T / R_eq

[0065] Where T is the reaction torque detected by torque sensing unit 2, and R_eq is the equivalent winding radius of winding wheel 6.

[0066] The control and acquisition unit also calculates the tendon ligament output displacement x based on the output angle θ of the motor or joint module 5 and the equivalent winding radius R_eq of the winding wheel 6.

[0067] x = R_eq·θ

[0068] When considering changes in the elastic elongation, slippage, or number of winding layers of the tendon ligament, the control and acquisition unit can correct the output tension and output displacement based on calibration parameters or compensation models.

[0069] Torque sensing unit 2: such as Figure 4 and Figure 5 As shown, the torque sensing unit 2 is a ring-shaped static torque sensor. The attached diagram illustrates the torque sensing unit 2 as a ring-shaped structure with mounting holes and a signal lead-out section to show its installation position and force transmission relationship. The static torque sensor internally includes an elastic body, a strain-sensitive element, a signal conditioning circuit, and a signal lead-out section. The reaction torque generated when the motor or joint module 5 drives the winding wheel 6 to wind the tendon rope is transmitted to the torque sensing unit 2 via the outer shell 4 and the internal support platform 3, causing the elastic body to undergo slight elastic deformation. The strain-sensitive element detects the elastic deformation and outputs an electrical signal. The signal conditioning circuit amplifies, filters, or converts the electrical signal before outputting it to the control and acquisition unit. The ring-shaped static torque sensor includes a first end face connection section 21, a second end face connection section 22, and a signal lead-out section.

[0070] In other embodiments, the torque sensing unit 2 may also employ a flange-type static torque sensor, a disc-type static torque sensor, or a shaft-type torque sensor.

[0071] Connection structure between motor or joint module 5 and housing 4: such as Figure 3 and Figure 7As shown, the motor or joint module 5 is connected to the lower surface connection hole 42 of the lower surface of the housing 4 through its end fixing hole 51. This structure fixes the motor or joint module 5 inside the housing 4 while preventing the motor or joint module 5 from being directly connected to the bone fixation plate 1. Thus, the reaction torque generated by the motor or joint module 5 when driving the winding wheel 6 can be transmitted to the torque sensing unit 2 through the housing 4 and the internal support platform 3.

[0072] Connection structure between internal support platform 3 and outer shell 4: such as Figure 6 and Figure 7 As shown, the internal support platform 3 has multiple mounting holes 31 arranged circumferentially, and the outer shell 4 has side surface connection holes 43 corresponding to the mounting holes 31. Fasteners 9 pass through the mounting holes 31 and the side surface connection holes 43 to fix the internal support platform 3 to the outer shell 4. This connection structure is used to reliably transmit the reaction torque borne by the outer shell 4 to the internal support platform 3, and further to the torque sensing unit 2.

[0073] Circular tendon rope version 7: as shown Figure 1 and Figure 7 As shown, the tendon cord is a circular tendon cord 7. The circular tendon cord 7 can be a high-strength fiber cord, a composite fiber cord, a flexible steel cable, or a circular rope with a flexible coating.

[0074] When the tendon cord is a circular tendon cord 7, the output guide structure 8 includes a first lead-out boss 44 disposed on the housing 4. A circular guide hole 81 is provided within the first lead-out boss 44, and a wear-resistant guide bushing 82 is installed within the circular guide hole 81. The wear-resistant guide bushing 82 can be a tungsten carbide guide eye, a cemented carbide guide bushing, a ceramic guide bushing, a zirconia guide bushing, or a low-friction polymer guide bushing. After the circular tendon cord 7 is led out from the winding reel 6, it is guided to the outside through the wear-resistant guide bushing 82.

[0075] This structure can reduce friction and wear between the circular tendon cord 7 and the outer shell 4, and improve the stability of the tendon cord exit and the lifespan of the artificial muscle.

[0076] Stretch band 71 version: as Figure 2 and Figure 8 As shown, in another embodiment, the tendon cord is a banded tendon cord 71. The banded tendon cord 71 can be a banded braided tendon, a flat rope, or a composite flexible banded force transmission element.

[0077] When the tendon cord is a band-shaped tendon cord 71, the output guide structure 8 includes a second lead-out boss 45 disposed on the housing 4. A pair of columnar guide members 83 are mounted on the second lead-out boss 45, forming a band-shaped tendon cord guide gap 84 between the two columnar guide members 83. The band-shaped tendon cord 71 is led out through the band-shaped tendon cord guide gap 84.

[0078] The columnar guide 83 can be a cylindrical threaded pin, a smooth shaft pin, a guide pin with a low-friction sleeve, or a rolling guide pin. The band tendon guide clearance 84 is used to limit the lateral displacement and overturning of the band tendon 71, so that the band tendon 71 is stably output in a predetermined direction.

[0079] Winding reel 6 structure: such as Figure 9 As shown, the winding reel 6 includes a first winding reel 61 and a second winding reel 62. The first winding reel 61 is used to adapt the circular tendon rope 7, and the second winding reel 62 is used to adapt the band-shaped tendon rope 71.

[0080] The first winding wheel 61 may be provided with a narrow-slot winding section 611 to accommodate the circular tendon rope 7. The second winding wheel 62 may be provided with a wide-slot winding section 621, a lateral limiting flange 622, and a rounded transition exit section 623 to accommodate the strip tendon rope 71. The wheel height, winding slot width, or flange spacing of the second winding wheel 62 may be greater than that of the first winding wheel 61.

[0081] like Figure 10 As shown, the winding reel 6 is provided with a trumpet-shaped winding structure 63. The trumpet-shaped winding structure 63 is wider on the outside and narrower on the inside along the direction in which the tendon cord enters the winding reel 6. The trumpet-shaped winding structure 63 includes an outer guide area 631 and an inner limiting area 632. The opening width of the outer guide area 631 is greater than the width of the inner limiting area 632. The outer guide area 631 is used to improve the feed tolerance when the tendon cord enters the winding reel 6, so that the tendon cord can stably enter the winding area. The inner limiting area 632 is used to limit the interlayer displacement of the tendon cord after winding, reducing the risk of the outer tendon cord getting caught in the gap of the inner tendon cord.

[0082] This structure can improve the stability of tendon cord reeling and reduce cord tangling, cord clamping, and tendon cord wear.

[0083] This invention also provides a method for preparing a tendon-type artificial muscle with force displacement self-sensing function, comprising the following steps:

[0084] S1, Prepare or select the following components: 1. Bone fixation plate; 2. Torque sensing unit; 3. Internal support platform; 4. Outer shell; 5. Motor or joint module; 6. Winding wheel; 7. Tendon rope; 8. Output guide structure.

[0085] S2, connect the first end of the torque sensing unit 2 to the bone fixation plate 1;

[0086] S3, connect the internal support platform 3 to the second end of the torque sensing unit 2;

[0087] S4, the outer shell 4 is fitted onto the outside of the inner support platform 3, and the outer shell 4 is fixedly connected to the inner support platform 3;

[0088] S5, install the motor or joint module 5 into the housing 4, and fix the end fixing hole 51 of the motor or joint module 5 to the lower surface of the housing 4 by threaded connection;

[0089] S6, mount the winding wheel 6 to the output end face 52 of the motor or joint module 5;

[0090] S7, fix one end of the tendon rope to the winding wheel 6, and guide the other end out through the output guide structure 8;

[0091] S8 applies pretension to the tendon ligament and completes the calibration of the zero torque point and zero displacement point;

[0092] S9 establishes the mapping relationship between the reaction torque, the equivalent winding radius of the winding wheel 6, and the output tension of the tendon rope;

[0093] S10, establish the mapping relationship between the output angle of the motor or joint module 5, the equivalent winding radius of the winding wheel 6, and the output displacement of the tendon rope;

[0094] S11, write the mapping relationship or calibration parameters into the control and acquisition unit, so that the artificial muscle can realize self-sensing of output tension and output displacement during the working process.

[0095] Status determination method: The control and acquisition unit can acquire the operating current of the motor or joint module 5 and obtain an auxiliary torque estimate based on the operating current. The auxiliary torque estimate can be used to verify, compensate for, or determine anomalies in the reaction torque detected by the torque sensing unit 2.

[0096] The control and acquisition unit can obtain the equivalent stiffness of the artificial muscle based on the relationship between the output tension and displacement of the tendon ligament. When an abnormal decrease in output tension, abnormal change in output displacement, sudden change in reaction torque, or abnormal increase in current is detected, the control and acquisition unit can determine that the tendon ligament is at risk of slackness, slippage, overload, or breakage, and control the motor or joint module 5 to stop, decelerate, release, or issue an alarm.

[0097] Although the present invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, as long as there is no structural conflict, the features in the disclosed embodiments can be combined with each other in any manner. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A tendon-type artificial muscle with force displacement self-sensing function, characterized in that, The system includes a bone fixation plate, a torque sensing unit, an internal support platform, a housing, a motor or joint module, a winding reel, tendon ties, an output guide structure, an end connection mechanism, and a control and acquisition unit. The first and second end face connections of the torque sensing unit are respectively connected to the bone fixation plate and the internal support platform. The housing is fixedly sleeved on the outside of the internal support platform. The end fixing holes of the motor or joint module are threadedly connected to the lower surface connection holes of the housing, and the motor or joint module is not directly connected to the bone fixation plate. The winding reel is fixed to the output end face of the motor or joint module for winding or releasing the tendon ties. One end of the tendon ties is connected to the winding reel, and the other end is led out through the output guide structure and connected to the end connection mechanism. The winding reel includes a first winding reel for adapting to the circular tendon ties and a... A second winding wheel is used to adapt to the tendon cord; the wheel height, winding groove width, or flange spacing of the second winding wheel is greater than that of the first winding wheel; the first winding wheel is provided with a narrow groove winding section; the second winding wheel is provided with a wide groove winding section, a lateral limiting flange, and a rounded transition wire exit section; the control and acquisition unit is connected to the torque sensing unit and the motor or joint module; the reaction torque generated when the motor or joint module drives the winding wheel to wind or release the tendon cord is transmitted to the torque sensing unit through the end fixing hole of the motor or joint module, the outer shell, and the internal support platform; the control and acquisition unit obtains the output tension of the tendon cord based on the reaction torque detected by the torque sensing unit and the equivalent winding radius of the winding wheel, and obtains the output displacement of the tendon cord based on the output angle of the motor or joint module and the equivalent winding radius of the winding wheel.

2. The tendon-type artificial muscle with force displacement self-sensing function according to claim 1, characterized in that, The torque sensing unit is a ring-shaped static torque sensor, which includes a ring-shaped elastomer, a first end face connection portion, a second end face connection portion, a strain-sensitive element, a signal conditioning circuit, and a signal output portion; the strain-sensitive element is used to detect the elastic deformation of the ring-shaped elastomer under the action of reaction torque.

3. The tendon-type artificial muscle with force displacement self-sensing function according to claim 1, characterized in that, The first end face connection part and the second end face connection part of the torque sensing unit are respectively connected to the bone fixation plate and the internal support platform by fasteners. The internal support platform is connected to the outer shell by fasteners. The end fixing hole of the motor or joint module is connected to the lower surface connection hole of the lower surface of the outer shell by fasteners. The winding wheel is connected to the output end face of the motor or joint module by fasteners. The internal support platform is provided with multiple mounting holes in its circumference, and the outer shell is provided with side surface connection holes corresponding to the mounting holes. The internal support platform and the outer shell are fixedly connected by fasteners passing through the mounting holes and side surface connection holes. The inner surface of the housing is provided with multiple lower surface connection holes, fixing ring grooves or connecting bosses for fixing the motor or joint module. The motor or joint module is fixedly connected to the lower surface connection holes, fixing ring grooves or connecting bosses of the housing through its end fixing holes.

4. The tendon-type artificial muscle with force displacement self-sensing function according to claim 1, characterized in that, The winding wheel is provided with a trumpet-shaped winding structure. The trumpet-shaped winding structure is set with the outer part being wider and the inner part being narrower along the direction in which the tendon rope enters the winding wheel. It is used to guide the tendon rope to enter the winding area stably and to limit the outer tendon rope from winding into the gap of the inner tendon rope. The trumpet-shaped winding structure includes an outer guide area and an inner limiting area. The opening width of the outer guide area is greater than the width of the inner limiting area. The outer guide area is used to improve the tolerance of tendon cord entry, and the inner limiting area is used to limit the interlayer displacement of tendon cord winding.

5. A tendon-type artificial muscle with force displacement self-sensing function according to claim 4, characterized in that, When the tendon cord is a circular tendon cord, the output guide structure includes a first lead-out boss disposed on the housing, the first lead-out boss having a circular guide hole, and a wear-resistant guide bushing installed in the circular guide hole; the wear-resistant guide bushing is one of tungsten carbide guide eye, hard alloy guide bushing, ceramic guide bushing, zirconium oxide guide bushing or low-friction polymer guide bushing.

6. A tendon-type artificial muscle with force displacement self-sensing function according to claim 4, characterized in that, When the tendon cord is a band tendon cord, the output guide structure includes a second lead-out boss disposed on the housing, and a pair of columnar guide members are installed on the second lead-out boss. A band tendon cord guide gap is formed between the two columnar guide members, and the band tendon cord is led out through the band tendon cord guide gap to limit the lateral displacement and overturning of the band tendon cord.

7. A tendon-type artificial muscle with force displacement self-sensing function according to claim 1, characterized in that, The control and acquisition unit is also used to acquire the operating current of the motor or joint module, and obtain an auxiliary torque estimate based on the operating current. The auxiliary torque estimate is used to verify, compensate, or judge the abnormality of the reaction torque detected by the torque sensing unit. The control and acquisition unit obtains the equivalent stiffness, load state, slippage state, overload state, or breakage state of the artificial muscle based on the relationship between the output tension and displacement of the tendon rope.

8. A method for preparing a ligament-type artificial muscle with force displacement self-sensing function, used to prepare a ligament-type artificial muscle with force displacement self-sensing function as described in any one of claims 1-7, characterized in that, Includes the following steps: S1, prepare or select a bone fixation plate, torque sensing unit, internal support platform, shell, motor or joint module, winding wheel, tendon rope, output guide structure, end connection mechanism and control and acquisition unit; S2, connect the first end face of the torque sensing unit to the bone fixation plate; S3 connects the internal support platform to the second end face connection of the torque sensing unit; S4, fit the outer shell onto the outside of the inner support platform and fix the outer shell to the inner support platform; S5, assemble the motor or joint module into the housing, and fix the end fixing hole of the motor or joint module to the lower surface connection hole of the housing by thread; S6, mount the winding wheel to the output end face of the motor or joint module; S7, fix one end of the tendon rope to the winding wheel, and lead the other end out through the output guide structure and connect it to the end connection mechanism; S8 applies pretension to the tendon ligament and completes the calibration of the zero torque point and zero displacement point; S9, establish the mapping relationship between reaction torque, equivalent winding radius of the winding wheel and tendon cable output tension; S10, establish the mapping relationship between the output angle of the motor or joint module, the equivalent winding radius of the winding wheel and the output displacement of the tendon rope; S11, The mapping relationship or calibration parameters are written into the control and acquisition unit so that the artificial muscle can realize self-sensing of output tension and output displacement during the working process.

9. The method for preparing a tendon-type artificial muscle with force displacement self-sensing function according to claim 8, characterized in that, When the tendon cord is circular, a first winding wheel and a first lead-out boss with a wear-resistant guide bushing are selected; when the tendon cord is ribbon-shaped, a second winding wheel and a second lead-out boss with paired columnar guides are selected.

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