Performance-controllable spiral-wound artificial muscle and preparation device and regulation method thereof

Abstract

The application discloses a controllable performance spiral winding type artificial muscle and a preparation device and a regulation method thereof. The device comprises a winding device part, a spiral device part and a controller and a main control part. The method comprises the following steps: winding a precursor polymer fiber and a metal nickel wire through the winding device part, and then performing an electric heating treatment to obtain a treatment sample; performing a spiral treatment on a mold mandrel, a spiral guide groove and the treatment sample through the spiral device part, and then performing a heat treatment to obtain a spiral sample; and removing the spiral guide groove on the spiral sample to obtain the spiral winding type artificial muscle. The application adopts special winding and spiral equipment to adjust a manufacturing process, and completes a spiral winding structure artificial muscle with specific parameters, so that the performance stability and the performance controllability are greatly improved, and then the work capacity of the artificial muscle in the face of different work objects is improved, the coordinated control on the output force and the output displacement is realized, and the application range in the fields of bionic robots, soft robots, wearable exoskeletons and the like is expanded.

Description

Technical Field

[0001] This invention relates to a spiral-wound artificial muscle, specifically to a spiral-wound artificial muscle with controllable performance, its preparation device, and its control method. Background Technology

[0002] As a flexible actuator, artificial muscles can convert external energy into mechanical energy. In recent years, they have attracted widespread attention due to their low noise, long stroke, and good biocompatibility, and have been widely used in advanced fields such as bionic robots, soft robots, and exoskeletons. Currently, many functional materials have been used to make artificial muscles, such as shape memory alloys, shape memory polymers, dielectric elastomers, ion-exchange polymer metal composites, and carbon nanotubes. Common artificial muscles can be divided into five categories: temperature-responsive, chemical-responsive, aerodynamic-responsive, electrical-responsive, and magnetic-responsive, among which temperature-responsive artificial muscles are the most common.

[0003] A new type of artificial muscle, made from inexpensive yet high-strength polymer fibers such as fishing line or sewing thread, has been proposed. This artificial muscle is created simply by inserting polymer fibers into a spiral. It can achieve a maximum length change of 49% under varying environmental temperatures and delivers mechanical work equivalent to 100 times that of a human biceps brachii of the same weight, with a power-to-weight ratio comparable to a modern jet engine. The spiral-wound artificial muscle, with its excellent actuation performance and broad application prospects, has attracted increasing research attention from scholars.

[0004] However, the structural parameters of helical coiled artificial muscles are affected by the manufacturing process, which in turn affects the output performance of the artificial muscles. The instability and uncontrollability of the manufacturing process parameters lead to a large degree of randomness in the performance of the finished muscles, which seriously affects the driving ability of the muscles after bundle formation. Furthermore, with the diversification of robot working environments and objects, helical coiled artificial muscles have put forward more diverse requirements for output performance. However, there is currently a lack of prediction, control, manufacturing, and testing methods and equipment that combine mechanical structural models, making it impossible to achieve parameterized manufacturing and performance control of helical coiled artificial muscles. This greatly limits its diversified development in the field of robotics. Summary of the Invention

[0005] To address the problems existing in the background art, this invention provides a controllable spiral-wound artificial muscle and its preparation device and control method. This invention is an artificial muscle made of nylon 66 yarn wound and twisted with nickel wire, whose performance can be adjusted through structural modification. It also includes a device and method for preparing and controlling the structural parameters of this artificial muscle. Compared to existing heat-driven polymer spiral-wound artificial muscles, this invention controls the muscle structure through a special preparation device, achieving direct control of key parameters such as the number of winding turns, twist angle, helix angle, and spring coefficient, thereby controlling the force and position performance of the artificial muscle.

[0006] The technical solution adopted in this invention is:

[0007] I. A device for preparing a spiral-wound artificial muscle with controllable performance:

[0008] The preparation apparatus includes a winding device section mounted on an apparatus mounting frame for winding a winding structure containing an accompanying polymer and metal wire.

[0009] The preparation apparatus includes a spiral device part mounted on a device mounting frame for preparing a spiral-wound artificial muscle by spiraling the coiled structure.

[0010] The preparation apparatus includes a controller and a main control unit mounted on an apparatus mounting frame for controlling the winding process of the winding device and the spiral process of the spiral device. The controller and the main control unit include a stepper motor controller and a main control terminal that are electrically connected to each other. Both the stepper motor controller and the main control terminal are electrically connected to the winding device and the spiral device.

[0011] The stepper motor controller is responsible for transmitting the speed and direction drive signals of all stepper motors. The main control terminal is responsible for writing programs to coordinate and control the moving speed and direction of the moving slide and the rotation speed and direction of other stepper motors, so as to achieve the purpose of fiber winding, spiral and structural parameter control.

[0012] The winding device includes a slide stepper motor, a first trapezoidal slide rail, a movable mounting platform, a fixed mounting platform, a laser position sensor, and a first stepper motor. The first trapezoidal slide rail is horizontally mounted on the device mounting frame. The body of the slide stepper motor is mounted on the device mounting frame and located at one end of the first trapezoidal slide rail. The rotation shaft of the slide stepper motor is horizontal and synchronously connected to one end of the first trapezoidal slide rail. The fixed mounting platform is mounted on the other end of the first trapezoidal slide rail. The movable mounting platform is slidably mounted on the first trapezoidal slide rail. The movable mounting platform and the fixed mounting platform are arranged facing each other. The laser position sensor is mounted on the movable mounting platform near the fixed mounting platform. One side of the platform faces the fixed mounting platform. The body of the first stepper motor is mounted on the fixed mounting platform on the side away from the movable mounting platform. The rotating shaft of the first stepper motor passes horizontally through the fixed mounting platform and is parallel to the length direction of the first trapezoidal slide rail. One end of the polymer fiber to be wound is connected to the rotating shaft of the first stepper motor through a hanging ring and a coupling. The other end of the polymer fiber to be wound is connected to the movable mounting platform through a hook. The polymer fiber to be wound is arranged horizontally and parallel to the length direction of the first trapezoidal slide rail. The slide stepper motor and the first stepper motor are both electrically connected to the stepper motor controller, and the laser position sensor is electrically connected to the main control terminal.

[0013] The mobile mounting platform mainly controls the axial movement of the polymer fiber to be wound during the winding process. The laser position sensor can calculate the current fiber winding length in real time. The first stepper motor controls the winding of the polymer fiber to be wound. The tension and compression sensor is an additional device. During testing, one end of the artificial muscle to be tested is connected to the mobile mounting platform through a hanging ring, and the other end is connected to the tension and compression sensor through a hanging ring. The tension and compression sensor is then connected to the rotating shaft of the first stepper motor through a hanging ring and a coupling. It can work with the laser position sensor to perform performance testing of the artificial muscle and record the output force position during the artificial muscle testing process. The stepper motor controller and the main control terminal realize the transmission of drive signals for all motors and the upper computer program writing.

[0014] The spiral device includes a second trapezoidal slide rail, a second stepper motor, a moving wire feeding table, a third stepper motor, a fourth stepper motor, a tensioning spool, and a raw material spool. The second trapezoidal slide rail is horizontally mounted on the device mounting frame. The body of the second stepper motor is mounted on the device mounting frame and located at one end of the second trapezoidal slide rail. The rotation shaft of the second stepper motor is horizontal and synchronously connected to one end of the second trapezoidal slide rail. The other end of the second trapezoidal slide rail is connected to the device mounting frame. The moving wire feeding table is slidably mounted on the second trapezoidal slide rail. The bodies of the third and fourth stepper motors are both mounted on the device mounting frame. The stepper motors are located on the same side at both ends of the second trapezoidal slide rail. The rotation axes of the third and fourth stepper motors are horizontal and directly opposite each other. The rotation axes of the third and fourth stepper motors are connected to both ends of the structure to be spirally wound via couplings. The structure to be spirally wound is horizontal and parallel to the length direction of the second trapezoidal slide rail. The moving wire feeding table is located on one side of the structure to be spirally wound, and its height is consistent with that of the structure to be spirally wound. The tensioning spool and the raw material spool are mounted on the device mounting frame and located to the side of the structure to be spirally wound. The second, third, and fourth stepper motors are all electrically connected to the stepper motor controller.

[0015] II. A method for controlling the preparation of a spiral-wound artificial muscle using a preparation device, comprising:

[0016] 1) The precursor polymer fiber is used as the polymer fiber to be wound. One end of the precursor polymer fiber is connected to the mobile mounting platform through a hook, and the other end of the precursor polymer fiber is connected to the rotating shaft of the first stepper motor. The controller and the main control terminal of the main control part drive the slide stepper motor and the first stepper motor to run through the stepper motor controller, rotate the precursor polymer fiber in the direction of fiber untwisting, and finally completely untwist it to obtain untwisted sample A.

[0017] 2) The nickel wire is evenly wound onto the untwisted sample A. The main control terminal drives the slide stepper motor and the first stepper motor through the stepper motor controller, rotating the untwisted sample A and the nickel wire together in the direction of fiber twisting. The laser position sensor calculates the current fiber winding length in real time, and the first stepper motor feeds back the number of pulses in real time to calculate the number of winding turns n. i After reaching the preset winding length, number of turns and twist angle, the drive slide stepper motor and the first stepper motor are turned off to obtain the wound fiber sample B; the nickel wire in the wound fiber sample B is heated by electricity to finally obtain the processed sample C.

[0018] 3) Select copper wire as the mold mandrel according to the preset spring coefficient and helix angle, and nickel-chromium alloy wire as the helical guide groove. Connect the two ends of the mold mandrel to the rotating shafts of the third and fourth stepper motors respectively through couplings. Connect one end of the helical guide groove to the rotating shaft of the third or fourth stepper motor through a coupling. The other end of the helical guide groove is a free end. The moving wire feeding table has a groove and fits on the mold mandrel and the helical guide groove. The main control terminal drives the second, third and fourth stepper motors through the stepper motor controller. The moving wire feeding table moves from one end of the second trapezoidal slide rail to the other end, and the helical guide groove is evenly wound onto the mold mandrel according to the preset pitch to obtain the mandrel mold. The mold mandrel remains unchanged.

[0019] 4) Connect both ends of the mandrel mold to the rotating shafts of the third and fourth stepper motors respectively via couplings. Wind the processed sample C onto the raw material spool. Connect one end of the processed sample C to the coupling of the rotating shaft of the fourth stepper motor via the grooves of the tension spool and the moving feed table. Drive the second, third, and fourth stepper motors to run. Move the moving feed table from the fourth stepper motor to the third stepper motor. Wind the processed sample C onto the mandrel mold along the spiral guide groove according to the preset number of spiral turns to obtain the first spiral sample D. After heat treatment of the first spiral sample D, obtain the second spiral sample E.

[0020] 5) Connect the two ends of the second spiral sample E to the rotating shafts of the third and fourth stepper motors respectively through couplings. Move the groove of the wire feeding table onto the second spiral sample E, and remove the spiral guide groove on the second spiral sample E at a constant speed. Then remove the mold mandrel to obtain the second spiral sample E as the final spiral-wound artificial muscle, thus completing the preparation and control.

[0021] If it is necessary to test the force and position performance of the finished artificial muscle, one end can be fixed to the movable mounting platform of the winding device, and the other end can be fixed to the tension and compression sensor. Then, the tension and compression sensor can be fixed to the rotating shaft of the first stepper motor mounted on the fixed mounting platform. With the tension control of the movable mounting platform, the force and position experimental data of the muscle can be obtained.

[0022] In step 1), the precursor polymer fiber is specifically made of three strands of nylon 66 material of 210D to 1260D, which are composite wound together. The length of the precursor polymer fiber is l0 = 50-250mm and the diameter is d0 = 0.3-0.7mm.

[0023] In step 2), uniformly winding the nickel wire onto the untwisted sample A specifically involves winding a nickel wire with a diameter of 0.1-0.3 mm and a length approximately 80 mm longer than the untwisted sample A around the untwisted sample A 4-5 times along the fiber twisting direction. Heating the nickel wire wound in the fiber sample B involves first connecting both ends of the nickel wire to a DC power supply, adjusting the power supply output current, and applying a constant square wave current with a period of 90-120 seconds and a duty cycle of 50%. The current temperature T is then detected using a thermal imaging sensor. i The peak temperature of the nickel wire is controlled at around 90-110℃, the thermal imaging sensor is turned off, and the timer records the current temperature holding time t. i The sample was heat-treated for approximately 15-25 minutes to reset its stress equilibrium state. After the heat treatment was completed, the DC power supply was turned off to obtain the treated sample C. The temperature coefficient of resistivity α of the nickel wire was 0.005495 ​​Ω / ℃.

[0024] In step 3), the diameter D0 of the copper wire is 0.2-1 mm, and the diameter of the nickel-chromium alloy wire is 0.1-0.5 mm.

[0025] In step 4), the heat treatment specifically involves heat treatment in a constant temperature chamber at 160-180℃ for 20-30 minutes.

[0026] III. The spiral-wound artificial muscle prepared using the above-described preparation device or the spiral-wound artificial muscle prepared using the above-described control method.

[0027] The beneficial effects of this invention are:

[0028] In the field of polymer helical wound artificial muscles and their fabrication, compared with existing artificial muscles and their fabrication equipment and methods, this invention uses mechanical analysis methods to establish a mathematical model between the structural parameters and force properties of artificial muscles, and uses special winding and helical equipment to adjust the fabrication process to complete helical wound artificial muscles with specific parameters. This invention can greatly improve the performance stability and controllability of helical wound artificial muscles, thereby improving the working ability of artificial muscles when facing different work objects, realizing coordinated control of output force and output displacement of helical wound artificial muscles, and expanding their application scope in fields such as bionic robots, soft robots, and wearable exoskeletons. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of a spiral-wound artificial muscle preparation device with controllable performance according to the present invention;

[0030] Figure 2 This is a schematic diagram of the winding device.

[0031] Figure 3This is a schematic diagram of the screw mechanism.

[0032] Figure 4 This is a schematic diagram of the controller and main control unit;

[0033] Figure 5 A flowchart of a method for preparing a spiral-wound artificial muscle with controllable performance (wound part);

[0034] Figure 6 A flowchart of a method for preparing a spiral-wound artificial muscle with controllable performance (spiral part);

[0035] Figure 7 A schematic diagram of the mandrel mold used in the screw device;

[0036] Figure 8 This is a schematic diagram of a spiral-wound artificial muscle with controllable performance.

[0037] Figure 9 A schematic diagram illustrating the dimensions involved in modeling a spiral-wound artificial muscle;

[0038] In the diagram: 100, winding device; 110, slide stepper motor; 120, first trapezoidal slide rail; 130, movable mounting platform; 140, fixed mounting platform; 150, polymer fiber to be wound; 160, laser position sensor; 170, tension / compression sensor; 180, first stepper motor; 200, spiral device; 210, second stepper motor; 220, movable wire feeding platform; 230, third stepper motor; 240, fourth stepper motor; 250, tensioning spool; 260, raw material spool; 300, controller and main control unit; 310, stepper motor controller; 320, main control terminal. Detailed Implementation

[0039] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] like Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, the apparatus for preparing a controllable spiral-wound artificial muscle according to the present invention includes a winding device part 100, a spiral device part 200, and a controller and main control part 300. The winding device part 100 is mounted on the device mounting frame and is used to wind a winding structure accompanied by polymer and metal wire. The spiral device part 200 is mounted on the device mounting frame and is used to spiral the winding structure to prepare a spiral-wound artificial muscle. The controller and main control part 300 is mounted on the device mounting frame and is used to control the winding process of the winding device part 100 and the spiral device part 200. The controller and main control part 300 includes a stepper motor controller 310 and a main control terminal 320 that are electrically connected to each other. Both the stepper motor controller 310 and the main control terminal 320 are electrically connected to the winding device part 100 and the spiral device part 200.

[0041] The stepper motor controller 310 is responsible for transmitting the speed and direction drive signals of all stepper motors, while the main control terminal 320 is responsible for writing programs to coordinate and control the moving speed and direction of the moving slide and the rotation speed and direction of other stepper motors, so as to achieve the purpose of fiber winding, spiral and structural parameter control.

[0042] This invention discloses a performance-controllable spiral-wound artificial muscle fabrication device, specifically comprising two moving slides consisting of stepper motors, ball screws with a diameter of 6mm and a lead of 1mm, and trapezoidal grooves with an effective length of 300mm; three 28-stepper motors with a torque of 0.07 N·m; a laser position sensor with an accuracy of ±0.3mm; a tension / compression sensor with a range of 0-1kg and a sensitivity of 1-2mV / V; and necessary structural components, a controller, and a main control terminal. The device is constructed with an aluminum profile frame, with most structural components manufactured using 3D printing FDM technology. The motor support components are made of ABS material, while the remainder are made of PLA material.

[0043] like Figure 2As shown, the winding device 100 includes a slide stepper motor 110, a first trapezoidal slide rail 120, a movable mounting platform 130, a fixed mounting platform 140, a laser position sensor 160, and a first stepper motor 180. The first trapezoidal slide rail 120 is horizontally mounted on the device mounting frame. The body of the slide stepper motor 110 is mounted on the device mounting frame and located at one end of the first trapezoidal slide rail 120. The rotation shaft of the slide stepper motor 110 is horizontal and synchronously connected to one end of the first trapezoidal slide rail 120. The fixed mounting platform 140 is mounted on the other end of the first trapezoidal slide rail 120. The movable mounting platform 130 is slidably mounted on the first trapezoidal slide rail 120. The movable mounting platform 130 and the fixed mounting platform 140 are arranged facing each other. The laser position sensor 160 is mounted on the movable mounting platform 130 near the fixed mounting platform 140. The mounting platform 140 is positioned on one side facing the fixed mounting platform 140. The body of the first stepper motor 180 is mounted on the fixed mounting platform 140 on the side away from the movable mounting platform 130. The rotation shaft of the first stepper motor 180 passes horizontally through the fixed mounting platform 140 and is parallel to the length direction of the first trapezoidal slide rail 120. One end of the polymer fiber 150 to be wound is connected to the rotation shaft of the first stepper motor 180 via a hanging ring and a coupling. The other end of the polymer fiber 150 to be wound is connected to the movable mounting platform 130 via a hook. The polymer fiber 150 to be wound is arranged horizontally and is parallel to the length direction of the first trapezoidal slide rail 120. Both the slide stepper motor 110 and the first stepper motor 180 are electrically connected to the stepper motor controller 310, and the laser position sensor 160 is electrically connected to the main control terminal 320.

[0044] The mobile mounting platform 130 mainly controls the axial movement of the polymer fiber 150 to be wound during the winding process. The laser position sensor 160 can calculate the current fiber winding length in real time. The first stepper motor 180 controls the winding of the polymer fiber 150. The tension and compression sensor 170 is an additional device. During testing, one end of the artificial muscle to be tested is connected to the mobile mounting platform 130 through a hanging ring, and the other end is connected to the tension and compression sensor 170 through a hanging ring. The tension and compression sensor 170 is then connected to the rotating shaft of the first stepper motor 180 through a hanging ring and a coupling. It can work with the laser position sensor 160 to perform performance testing of the artificial muscle and record the output force position during the artificial muscle testing process. The stepper motor controller 310 and the main control terminal 320 realize the transmission of drive signals for all motors and the writing of upper computer programs.

[0045] When testing the performance of the artificial muscle, the winding device 100 can be equipped with a tension / compression sensor 170 on the right fixed mounting platform 140. The right end of the slide stepper motor 110 is connected to a ball screw with a diameter of 6mm and a pitch of 1mm, and a movable mounting platform 130 is connected in the middle. The movable mounting platform 130 moves left and right along the trapezoidal slide rail 120. The right side is fixedly connected to the fixed mounting platform 140 on the overall frame. The first stepper motor 180 for winding is installed on the fixed mounting platform 140. The motor is connected to the hanging ring bolt via a coupling. The polymer fiber 150 to be wound is connected to the hanging ring bolt through a circular hanging ring. If it is necessary to test the completed artificial muscle, a tension / compression sensor 170 can be installed between the hanging ring bolt and the artificial muscle to provide feedback on the output force of the artificial muscle, and a laser position sensor 160 can provide feedback on the output displacement of the artificial muscle.

[0046] like Figure 3 As shown, the spiral device 200 includes a second trapezoidal slide rail, a second stepper motor 210, a movable wire feeding table 220, a third stepper motor 230, a fourth stepper motor 240, a tensioning spool 250, and a raw material spool 260. The second trapezoidal slide rail is horizontally mounted on the device mounting frame. The body of the second stepper motor 210 is mounted on the device mounting frame and located at one end of the second trapezoidal slide rail. The rotation shaft of the second stepper motor 210 is horizontal and synchronously connected to one end of the second trapezoidal slide rail. The other end of the second trapezoidal slide rail is connected to the device mounting frame. The movable wire feeding table 220 is slidably mounted on the second trapezoidal slide rail. The bodies of the third stepper motor 230 and the fourth stepper motor 240 are both mounted on the device mounting frame. The fourth stepper motor 240 is located on the same side of both ends of the second trapezoidal slide rail. The rotation axes of the third stepper motor 230 and the fourth stepper motor 240 are horizontal and directly opposite each other. The rotation axes of the third stepper motor 230 and the fourth stepper motor 240 are connected to both ends of the structure to be spirally wound via couplings. The structure to be spirally wound is horizontal and parallel to the length direction of the second trapezoidal slide rail. The movable wire feeding table 220 is located on one side of the structure to be spirally wound, and its height is consistent with that of the structure to be spirally wound. The tensioning spool 250 and the raw material spool 260 are mounted on the device mounting frame and located on the side of the structure to be spirally wound. The second stepper motor 210, the third stepper motor 230 and the fourth stepper motor 240 are all electrically connected to the stepper motor controller 310.

[0047] The spiral device 200 includes a trapezoidal slide rail, a second stepper motor 210 for movement control, a moving wire feeding table 220, two third stepper motors 230 and a fourth stepper motor 240 for spiral operation, a tensioning spool 250, and a raw material spool 260. The rotating shaft of stepper motor 210 is connected to a ball screw with a diameter of 6mm and a pitch of 1mm, and is connected to the moving wire feeding table 220 in the middle. The moving wire feeding table 220 moves left and right along the moving slide rail. The rotating shafts of stepper motors 230 and 240 are connected to couplings. The two stepper motors 230 and 240 rotate collaboratively to form the spiral structure. The tensioning spool 250 is responsible for tensioning the metal wire or wound polymer fiber filament originating from the raw material spool 260.

[0048] The preparation device of the present invention includes a method for controlling the preparation of helical wound artificial muscles, comprising:

[0049] 1) The precursor polymer fiber is used as the polymer fiber to be wound 150. One end of the precursor polymer fiber is connected to the movable mounting table 130 through a hook, and the other end of the precursor polymer fiber is connected to the rotating shaft of the first stepper motor 180. The controller and the main control terminal 320 of the main control part 300 drive the slide stepper motor 110 and the first stepper motor 180 to run through the stepper motor controller 310, so that the precursor polymer fiber is rotated in the direction of fiber untwisting, and finally completely untwisted to obtain untwisted sample A.

[0050] In step 1), the precursor polymer fiber is specifically made of three strands of nylon 66 material with a length of 210D to 1260D, which are composite wound together. The precursor polymer fiber has a length of l0 = 50-250mm and a diameter of d0 = 0.3-0.7mm.

[0051] 2) The nickel wire is evenly wound onto the untwisted sample A. The main control terminal 320 drives the slide stepper motor 110 and the first stepper motor 180 through the stepper motor controller 310, rotating the untwisted sample A and the nickel wire together in the direction of fiber twisting. The laser position sensor 160 calculates the current fiber winding length in real time, and the first stepper motor 180 calculates the number of winding turns n by feeding back the number of pulses in real time. i After reaching the preset winding length, number of turns and twist angle, the drive slide stepper motor 110 and the first stepper motor 180 are turned off to obtain the wound fiber sample B; the nickel wire in the wound fiber sample B is heated by electricity to finally obtain the processed sample C.

[0052] In step 2), the uniform winding of the nickel wire onto the untwisted sample A specifically involves winding a nickel wire with a diameter of 0.1-0.3 mm and a length approximately 80 mm longer than the untwisted sample A around the untwisted sample A 4-5 times along the fiber twisting direction. The electrothermal heating treatment of the nickel wire wound in the fiber sample B involves first connecting both ends of the nickel wire to a DC power supply, adjusting the power supply output current, and applying a constant square wave current with a period of 90-120 seconds and a duty cycle of 50%. The current temperature T is then detected using a thermal imaging sensor. i The peak temperature of the nickel wire is controlled at around 90-110℃, the thermal imaging sensor is turned off, and the timer records the current temperature holding time t. i Heat treatment is performed for approximately 15-25 minutes to reset its stress equilibrium state. After the heat treatment is completed, the DC power supply is turned off to obtain the treated sample C.

[0053] The resistivity temperature coefficient α of nickel wire is 0.005495 ​​Ω / ℃.

[0054] 3) Select copper wire as the mold mandrel according to the preset spring coefficient and helix angle, and nickel-chromium alloy wire as the helical guide groove. Connect the two ends of the mold mandrel to the rotating shafts of the third stepper motor 230 and the fourth stepper motor 240 respectively through couplings. Connect one end of the helical guide groove to the rotating shaft of the third stepper motor 230 or the fourth stepper motor 240 through a coupling. The other end of the helical guide groove is a free end. The moving wire feeding table 220 is provided with a groove and fits on the mold mandrel and the helical guide groove. The main control terminal 320 drives the second stepper motor 210, the third stepper motor 230 and the fourth stepper motor 240 to run through the stepper motor controller 310. The moving wire feeding table 220 moves from one end of the second trapezoidal slide rail to the other end, and the helical guide groove is evenly wound onto the mold mandrel according to the preset pitch to obtain the mandrel mold. The mold mandrel remains unchanged.

[0055] In step 3), the diameter D0 of the copper wire is 0.2-1mm, and the diameter of the nickel-chromium alloy wire is 0.1-0.5mm.

[0056] 4) Connect both ends of the mandrel mold to the rotating shafts of the third stepper motor 230 and the fourth stepper motor 240 respectively via couplings. Wind the processed sample C onto the raw material spool 260. Connect one end of the processed sample C to the coupling of the rotating shaft of the fourth stepper motor 240 via the grooves of the tension spool 250 and the movable feed table 220. Drive the second stepper motor 210, the third stepper motor 230 and the fourth stepper motor 240 to run. Move the movable feed table 220 from the fourth stepper motor 240 to the third stepper motor 230. Wind the processed sample C onto the mandrel mold along the spiral guide groove according to the preset number of spiral turns to obtain the first spiral sample D. After heat treatment of the first spiral sample D, obtain the second spiral sample E.

[0057] In step 4), the heat treatment specifically involves heat treatment in a constant temperature chamber at 160-180℃ for 20-30 minutes.

[0058] 5) Connect the two ends of the second spiral sample E to the rotating shafts of the third stepper motor 230 and the fourth stepper motor 240 respectively through couplings. Move the groove of the wire feeding table 220 onto the second spiral sample E, and remove the spiral guide groove on the second spiral sample E at a constant speed. Then remove the mold mandrel to obtain the second spiral sample E as the final spiral-wound artificial muscle, thus completing the preparation and control.

[0059] If it is necessary to test the force position performance of the finished artificial muscle, one end can be fixed to the movable mounting platform 130 of the winding device part 100, and the other end can be fixed to the tension and compression sensor 170. Then, the tension and compression sensor 170 can be fixed to the rotating shaft of the first step motor 180 mounted on the fixed mounting platform 140. With the tension control of the movable mounting platform 130, the force position test data of the muscle can be obtained.

[0060] The main control terminal (320) is equipped with a performance prediction model. The performance control method is mainly based on the performance prediction model of the spiral-wound artificial muscle. By decoupling the performance requirements of the actuator, the specific output force performance requirements of the spiral-wound artificial muscle to be prepared are obtained. The performance prediction model optimizes the structural parameters of the artificial muscle winding and spiraling process through the force performance requirements, and clarifies the control trend of key structural parameters such as the number of pre-wound turns, winding length, winding twist angle, spring coefficient, number of spiral turns, pitch, and spiral angle, so as to achieve accurate control. In addition, the performance prediction model can clarify the influence trend and degree of each structural parameter on the final artificial muscle force performance, and realize the theoretical value of the output force performance of the artificial muscle by solving the structural parameters of the artificial muscle winding and spiral structure, so as to achieve performance prediction.

[0061] The output force performance of artificial muscles can be predicted by parameters such as the diameter, length, and material modulus of the raw materials used in the spiral-wound artificial muscle manufacturing process, as well as the structural parameters during the spiral winding process. Conversely, the influence of material parameters, winding process parameters, and spiral process parameters can be clarified by this model, thereby enabling directional control of the performance of artificial muscles.

[0062] Specific embodiments of the present invention are as follows:

[0063] like Figure 5As shown, the process of the spiral-wound artificial muscle preparation method (winding part) with controllable performance of the present invention is as follows: First, a polymer fiber raw material with a length l0 = 200 mm and a diameter d0 = 0.7 mm is installed on the winding device part 100. The raw material is made of three strands of 1260D nylon 66 yarn and wound together. Stepper motors 110 and 180 are turned on to rotate in the direction of fiber untwisting. After the pre-wound of the multi-strand yarn is unwound, sample A can be obtained. Then, a nickel-chromium alloy wire about 80 mm longer and 0.15 mm in diameter than sample A is taken out and evenly wound along the axis in the direction of fiber winding. After winding the fiber 5 times, set the required number of winding turns n0 and winding length l1, then start the stepper motors 110 and 180 to rotate in the direction of fiber twisting. Control the moving mounting table 130 to move at a uniform speed until the predetermined number of winding turns is reached, and then stop to obtain sample B. Subsequently, a square wave current with a constant period of 120s and a duty cycle of 50% is passed through both sides of the nickel-chromium alloy wire on the fiber surface to keep the highest heat treatment temperature of the wound fiber at about 100℃. After heat treatment for 20 minutes, stop and cool it to obtain the wound structure with polymer and metal wire, i.e., sample C. This completes the winding process.

[0064] like Figure 6As shown, the process of the controllable spiral-wound artificial muscle preparation method (spiral part) of the present invention is as follows: First, a mandrel mold for spiral shaping of polymer fiber is made. The manufacturing method is to install a copper mandrel with a required diameter D0 of 0.5 mm on the coupling of the two rotating shafts of the spiral device 200. A 0.4 mm diameter nickel-chromium alloy wire for making the spiral shaping groove is wound on the raw material wire spool 260. After the nickel-chromium alloy wire is tensioned by the wire spool 250, it is fixed on the rotating shaft of one side of the motor via the moving wire feeding table 220. Then, according to the specified pitch requirement P, a program is written to coordinate the moving speed of the moving wire feeding table 220 and the rotation speed of the motors 210, 230, and 240. The slide table and motor are started. When the nickel-chromium alloy wire is completely spiraled along the full length of the mandrel (the number of spirals must be greater than N), the slide table and motor are stopped, and the mandrel mold is completed. After the mold is completed, the two ends of the spiraled nickel-chromium alloy wire are fixed, and the slide table and motor are started in reverse to return to the origin. Then, the wound... Polymer fiber sample C is wound onto a raw material spool. After passing through the tension spool 250, it is fed into the spiral groove of the mandrel mold by the moving feed table 220. Then, stepper motors 210, 230, and 240 are activated to evenly wind sample C along the groove onto the mandrel mold according to the programmed sequence. After the fiber has been wound into N spirals, the fiber end is fixed to obtain sample D. Sample D is then removed and placed in a 180°C constant temperature oven for heat treatment for 30 minutes. During the heat treatment process, the metal spiral shaping groove on the mandrel mold restricts the flow of heat. To prevent thermal contraction of the artificial muscle and maintain the stability of parameters such as the helix angle and spring coefficient, the artificial muscle is removed after heat treatment to obtain sample E. In order to remove the artificial muscle, the two ends of the mold of sample E need to be re-fixed on the rotating shafts of the stepper motors 230 and 240 of the helical mechanism. The slide and stepper motor are started to remove the helical guide groove from the mandrel at a constant speed. Then, the spirally wound polymer is removed from the optical axis of the mandrel. This completes the entire process of preparing a helical wound artificial muscle with controllable performance.

[0065] like Figure 7 The diagram shows a mandrel mold used in the spiral process of this invention. The mandrel core material is copper wire, which has high thermal conductivity and can meet the rapid heating requirements in the heat treatment of artificial muscle. In addition, the mandrel diameter D0 can be adjusted between 0.2-1mm according to the spring coefficient requirements. The mandrel is wrapped with nickel-chromium alloy wire. The good Joule heating capacity of the nickel-chromium alloy wire when energized can be used for rapid energized heat treatment without the aid of a constant temperature chamber. The diameter of the nickel-chromium alloy wire needs to be adjusted between 0.1-0.5mm according to the diameter of the polymer fiber to be spiralized and the pitch requirements. The spiral pitch of the mandrel mold is P, which can be controlled by the combined translation speed of the moving slide and the rotation speed of the rotary motor.

[0066] like Figure 8The diagram shows a controllable spiral-wound artificial muscle of the present invention. It is manufactured by winding polymer fibers with nickel wire, completing the winding process, performing a first heat treatment, inserting the spiral into a mold, and performing a second heat treatment. The artificial muscle has a spiral shape overall, with nickel wire accompanying the spiral on the surface of the main spiral. Because the resistivity of the nickel wire is highly sensitive to temperature changes, it can be used for direct temperature sensing during Joule heating of the artificial muscle. The essence of the temperature sensing method is to indirectly obtain the temperature by monitoring the change in the impedance characteristics of the driving nickel wire with temperature. For example, when using a 0.15mm diameter nickel wire as the driving wire, its resistivity temperature coefficient is 0.005495Ω·℃. -1 As long as the reference resistance value R of the resistance wire at 25℃ is measured... 25℃ Then substitute the real-time resistance value R of the resistance wire measured during the driving process into T = 25 + (RR) 25℃ ) / (0.005495·R 25℃ By using this information, we can determine the current temperature T of the artificial muscle.

[0067] like Figure 9 The diagram shows the dimensions of the spiral-wound artificial muscle with controllable performance according to the present invention. From left to right, the raw material filament is formed by winding three strands of 1260D nylon 66 polymer fibers, with a diameter of d0 and a length of l0. After winding, the filament has a diameter of d1 and a length of l1, with a fiber twist angle of α. f Pre-wound polymer fibers (sample C); and fibers with a diameter of D, a length of H, and a helix angle of α after complete spiral winding. c Polymer spiral-wound artificial muscle.

[0068] Force analysis of a spiral-wound artificial muscle, under unheated conditions, reveals that, to maintain the equilibrium of the removed portion, an internal force system tangential to the fiber cross-section is required. This internal force system can be simplified to a force F along the axial direction of the coiled polymer. N The force F along the radial direction of the polymer winding Q Given the torque M and the unrotation force T, the helix angle of the helical structure is α. c In addition to the forces mentioned above, there is also a unrotation force T generated during heating. h At this point, the helix angle of the helical structure is α. c1 .

[0069] Analysis reveals the relationships between the main internal forces mentioned above. The displacement relationships of the artificial muscle under the spiral structure are as follows:

[0070] δ=f 11 Ff 12 T h

[0071]

[0072] Where δ represents the change in length of the artificial muscle; f 11 and f 12 The values ​​represent the influence of external forces and thermally induced unrotation forces on the length change, determined by the structure and materials of the artificial muscle, respectively; F represents the external force acting on the artificial muscle; E represents the elastic modulus of the nylon 66 material used; and G represents the shear modulus of the nylon 66 material used.

[0073] The relationship between the rate of change of the overall length of a spiral-structured artificial muscle and the degree of unwinding can be expressed as follows:

[0074]

[0075] The main parameters involved in the fabrication of a spiral structure are: Figure 7 The diagram shows the mandrel diameter D0 and pitch P of the spiral mold, where the pitch P can be expressed as P = H / N. If the mandrel diameter remains constant, increasing the pitch P in a spiral artificial muscle of the same length H will reduce the number of spirals N. Assuming that the degree of fiber untwisting Δn due to temperature changes is consistent, the overall length change rate will increase. Furthermore, increasing the pitch will also increase the spacing between adjacent spirals along the central axis of the spiral structure, providing more room for variation in the artificial muscle length. Another important parameter for the artificial muscle in the spiral structure is the spring constant C, which specifically characterizes the relationship between the overall diameter D of the spiral structure and the diameter d1 of the optical axis forming the spiral structure, as shown in the following formula:

[0076]

[0077] Adjusting the mandrel diameter will affect the spring coefficient C of the finished spiral artificial muscle. Increasing the mandrel diameter will increase the spring coefficient while keeping the precursor fiber diameter d0, length l0, and number of turns n0 constant. Under the same initial helix angle and other parameters, a larger spring coefficient will cause a greater change in the helix angle, which in turn will result in a greater change in the overall length of the artificial muscle.

[0078] In addition, adjusting the initial fiber length l0 and diameter d0, as well as the number of turns n0 during fiber winding, will also have a certain impact on the output force performance of the artificial muscle. The twist angle α formed during fiber winding... f The twist angle of the wound fiber can be calculated from the length l1, diameter d1, and number of windings n0. In actual production, the twist angle of the wound fiber can be adjusted by adjusting the above parameters. The relationship between the twist angle and the above parameters is as follows:

[0079]

[0080] The relationship between the diameter and length before and after winding is shown in the following formula:

[0081]

[0082] The theoretical value of dimensions that are difficult to measure can be indirectly obtained from the above formula.

Claims

1. A device for preparing a spiral-wound artificial muscle with controllable performance, characterized in that: Includes a winding device portion (100) mounted on a device mounting frame for winding a winding structure of accompanying polymer and metal wire. Includes a spiral device part (200) mounted on a device mounting frame and used to prepare a spiral-wound artificial muscle by spiraling the coiled structure. The device includes a controller and a main control unit (300) mounted on a device mounting frame for controlling the winding process of the winding device part (100) and the spiral device part (200). The controller and the main control unit (300) includes a stepper motor controller (310) and a main control terminal (320) that are electrically connected to each other. Both the stepper motor controller (310) and the main control terminal (320) are electrically connected to the winding device part (100) and the spiral device part (200). The spiral device (200) includes a second trapezoidal slide rail, a second stepper motor (210), a movable wire feeding table (220), a third stepper motor (230), a fourth stepper motor (240), a tensioning spool (250), and a raw material spool (260). The second trapezoidal slide rail is horizontally mounted on the device mounting frame. The body of the second stepper motor (210) is mounted on the device mounting frame and located at one end of the second trapezoidal slide rail. The rotation shaft of the second stepper motor (210) is horizontal and synchronously connected to one end of the second trapezoidal slide rail. The other end of the second trapezoidal slide rail is connected to the device mounting frame. The movable wire feeding table (220) is slidably mounted on the second trapezoidal slide rail. The bodies of the third stepper motor (230) and the fourth stepper motor (240) are both mounted on the device mounting frame. The motor (230) and the fourth stepper motor (240) are located on the same side of both ends of the second trapezoidal slide rail. The rotation axes of the third stepper motor (230) and the fourth stepper motor (240) are horizontal and arranged facing each other. The rotation axes of the third stepper motor (230) and the fourth stepper motor (240) are connected to the two ends of the structure to be spirally wound through couplings. The structure to be spirally wound is horizontal and parallel to the length direction of the second trapezoidal slide rail. The moving wire feeding table (220) is located on one side of the structure to be spirally wound. The tensioning spool (250) and the raw material spool (260) are mounted on the device mounting frame and located on the side of the structure to be spirally wound. The second stepper motor (210), the third stepper motor (230) and the fourth stepper motor (240) are all electrically connected to the stepper motor controller (310).

2. The apparatus for preparing a spiral-wound artificial muscle with controllable performance according to claim 1, characterized in that: The winding device (100) includes a slide stepper motor (110), a first trapezoidal slide rail (120), a movable mounting platform (130), a fixed mounting platform (140), a laser position sensor (160), and a first stepper motor (180). The first trapezoidal slide rail (120) is horizontally mounted on the device mounting frame. The body of the slide stepper motor (110) is mounted on the device mounting frame and located at one end of the first trapezoidal slide rail (120). The rotation shaft of the slide stepper motor (110) is horizontal and synchronously connected to one end of the first trapezoidal slide rail (120). The fixed mounting platform (140) is mounted on the other end of the first trapezoidal slide rail (120). The movable mounting platform (130) is slidably mounted on the first trapezoidal slide rail (120). The movable mounting platform (130) and the fixed mounting platform (140) are arranged facing each other. The laser position sensor (160) is mounted on the movable mounting platform (130) close to the fixed mounting platform (140). The fixed mounting platform (140) is positioned on one side facing the fixed mounting platform (140). The body of the first stepper motor (180) is mounted on the fixed mounting platform (140) on the side away from the movable mounting platform (130). The rotating shaft of the first stepper motor (180) passes horizontally through the fixed mounting platform (140) and is parallel to the length direction of the first trapezoidal slide rail (120). One end of the polymer fiber (150) to be wound is connected to the rotating shaft of the first stepper motor (180) through a hanging ring and a coupling. The other end of the polymer fiber (150) to be wound is connected to the movable mounting platform (130) through a hook. The polymer fiber (150) to be wound is arranged horizontally and is parallel to the length direction of the first trapezoidal slide rail (120). The slide stepper motor (110) and the first stepper motor (180) are both electrically connected to the stepper motor controller (310). The laser position sensor (160) is electrically connected to the main control terminal (320).

3. The method for controlling the preparation of helical coiled artificial muscles using the preparation apparatus according to any one of claims 1-2, characterized in that, include: 1) The precursor polymer fiber is used as the polymer fiber to be wound (150). One end of the precursor polymer fiber is connected to the movable mounting table (130) by a hook, and the other end of the precursor polymer fiber is connected to the rotating shaft of the first stepper motor (180). The controller and the main control terminal (320) of the main control part (300) drive the slide stepper motor (110) and the first stepper motor (180) to run through the stepper motor controller (310), so that the precursor polymer fiber is rotated in the direction of fiber untwisting, and finally completely untwisted to obtain untwisted sample A. 2) The nickel wire is evenly wound onto the untwisted sample A. The main control terminal (320) drives the slide stepper motor (110) and the first stepper motor (180) through the stepper motor controller (310) to rotate the untwisted sample A and the nickel wire together in the direction of fiber twisting. The laser position sensor (160) calculates the current fiber winding length in real time. After the preset winding length, number of turns and twist angle are reached, the drive slide stepper motor (110) and the first stepper motor (180) are turned off to obtain the wound fiber sample B. The nickel wire in the wound fiber sample B is subjected to electric heating treatment to finally obtain the processed sample C. 3) Select copper wire as the mold mandrel and nickel-chromium alloy wire as the spiral guide groove. Connect the two ends of the mold mandrel to the rotating shafts of the third stepper motor (230) and the fourth stepper motor (240) respectively through couplings. Connect one end of the spiral guide groove to the rotating shaft of the third stepper motor (230) or the fourth stepper motor (240) through couplings. The other end of the spiral guide groove is a free end. The moving wire feeding table (220) is provided with a groove and is fitted on the mold mandrel and the spiral guide groove. The main control terminal (320) drives the second stepper motor (210), the third stepper motor (230) and the fourth stepper motor (240) to run through the stepper motor controller (310). The moving wire feeding table (220) moves from one end of the second trapezoidal slide rail to the other end and evenly winds the spiral guide groove onto the mold mandrel according to the preset pitch to obtain the mandrel mold. 4) Connect both ends of the mandrel mold to the rotating shafts of the third stepper motor (230) and the fourth stepper motor (240) respectively via couplings. Wind the processed sample C onto the raw material spool (260). Connect one end of the processed sample C to the coupling of the rotating shaft of the fourth stepper motor (240) via the grooves of the tension spool (250) and the moving feed table (220). Drive the second stepper motor (210), the third stepper motor (230) and the fourth stepper motor (240) to run. Move the moving feed table (220) from the fourth stepper motor (240) to the third stepper motor (230). Wind the processed sample C onto the mandrel mold along the spiral guide groove according to the preset number of spiral turns to obtain the first spiral sample D. After heat treatment of the first spiral sample D, obtain the second spiral sample E. 5) Connect the two ends of the second spiral sample E to the rotating shafts of the third stepper motor (230) and the fourth stepper motor (240) respectively through couplings. Move the groove of the wire feeding table (220) onto the second spiral sample E, and remove the spiral guide groove on the second spiral sample E at a constant speed. Then remove the mold mandrel to obtain the second spiral sample E as the final spiral-wound artificial muscle, thus completing the preparation and control.

4. The method for controlling the preparation of helical coiled artificial muscles using the preparation device according to claim 3, characterized in that: In step 1), the precursor polymer fiber is specifically made by composite winding of three strands of nylon 66 material with a density ranging from 210D to 1260D, and the length of the precursor polymer fiber is [missing information]. l 0 = 50-250mm, diameter is d 0 = 0.3-0.7 mm.

5. The method for controlling the preparation of spiral-wound artificial muscles using the preparation device according to claim 3, characterized in that: In step 2), the process of uniformly winding the nickel wire onto the untwisted sample A involves winding a nickel wire with a diameter of 0.1-0.3 mm and a length 80 mm longer than the untwisted sample A around the untwisted sample A 4-5 times along the fiber twisting direction. The process of electrically heating the nickel wire in the fiber sample B involves first connecting both ends of the nickel wire to a DC power supply and applying a constant square wave current with a period of 90-120 s and a duty cycle of 50%, controlling the peak temperature of the nickel wire at 90-110 ℃, and performing heat treatment for 15-25 minutes. After the heat treatment is completed, the DC power supply is turned off to obtain the treated sample C.

6. The method for controlling the preparation of helical coiled artificial muscles using the preparation device according to claim 3, characterized in that: In step 3), the diameter of the copper wire... D 0 is 0.2-1mm, and the diameter of the nickel-chromium alloy wire is 0.1-0.5mm.

7. The method for controlling the preparation of helical coiled artificial muscles using the preparation device according to claim 3, characterized in that: In step 4), the heat treatment specifically involves heat treatment in a constant temperature chamber at 160-180℃ for 20-30 minutes.

8. The spiral-wound artificial muscle prepared by the control method according to any one of claims 3-7.

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