A decoupled series elastic electric artificial muscle actuator and control method thereof

Abstract

A decoupled series elastic electric artificial muscle actuator and a control method thereof belong to the field of artificial muscle control technology. In the actuator of the present invention, the winding assembly and the motor assembly are arranged in sequence from front to back, and the winding assembly and the motor assembly are connected by an upper guide screw and a lower guide screw; the actuator has a built-in series elastic element, which has the function of buffering the change of rope tension, and can use the deformation degree of the elastic element to realize the measurement of rope tension; a non-contact linear displacement measurement method is used to measure the deformation of the elastic element, and the tension and length of the driving rope can be actively controlled to make it have characteristics similar to natural muscles; the actuator can be widely used in various mechanical arms, prostheses and exoskeleton devices. The active control method of rope tension of the present invention is a closed-loop active tension control method. The active control method of rope length of the present invention is a closed-loop active length control method.

Description

Technical Field

[0001] The present invention belongs to the technical field of artificial muscle actuators, and in particular relates to an electric artificial muscle actuator with a decoupled series elastic element and a control method thereof. Background Art

[0002] Artificial muscle actuators are actuators that mimic natural muscles and can contract autonomously under the stimulation of external signals. Artificial muscles have similar properties to natural muscles, so they have broader application prospects than traditional rigid actuators and are used in artificial exoskeletons, bionic prostheses, bionic walking aids, and bionic robots.

[0003] The main evaluation indicators of artificial muscle actuators include maximum stress, maximum strain, cycle life, power density, efficiency, etc. At present, there are artificial muscles that surpass natural muscles in some indicators. Relying on these artificial muscles, powerful bionic machines can be developed, which have great application potential in rehabilitation training, disaster relief, military reconnaissance and other fields.

[0004] The motor-driven artificial muscle actuator uses electrical energy as energy, uses a motor as a conversion device between electrical energy and mechanical energy, and uses mechanical devices such as pulleys, screws, and ropes as transmission devices to achieve the conversion of movement direction. This type of artificial muscle actuator is easy to control and manufacture, and also has high power density and environmental adaptability, and has broad application prospects. Summary of the invention

[0005] The present invention overcomes the shortcomings of the existing artificial muscle actuators, such as low integration, high layout difficulty, poor reliability, and difficulty in integrating series elastic elements, and proposes a design scheme for a rope-driven artificial muscle actuator. The actuator is not only an electric rope-driven artificial muscle actuator, but also a series elastic actuator because a series elastic element is integrated inside. The actuator has the ability to accurately measure and control the tension and length of the driving rope, and the present invention also provides a control method for the actuator.

[0006] A decoupled series elastic electric artificial muscle actuator, characterized in that it is composed of a winding assembly A and a motor assembly B, and the winding assembly A and the motor assembly B are arranged front and back; the winding assembly A is composed of a support plate A1, a bobbin A2, a rope 1, a screw I2, a sensor I3, a screw II4, a rotating magnetic steel 5, a bearing 6, a porcelain tube 7, a support pin 8, a sensor II9, and a screw 10; the motor assembly B is composed of a housing B1, a tail cover B2, a signal line I19, a signal line II20, a linear magnetic steel 21, a threaded hole I23, The threaded hole II 24, the reducer 25, the riveting point 26, the motor 27, the sleeve 28, the upper spring 32, the lower spring 33 and the control circuit 34 are composed; the reducer 25, the motor 27, the upper spring 32 and the lower spring 33 are arranged from front to back and are located in the housing B1; the support plate A1 and the bobbin A2 are arranged front and back; the output shaft 22 of the reducer 25 is fixedly connected with the shaft hole I 17 of the bobbin A2 through the screw 10; the front end outer ring of the bobbin A2 is movably connected with the hole II 12 of the support plate A1 through the bearing 6; the rear outer ring of the bobbin A2 The support plate A1 is provided with a hole Ⅰ11, a hole Ⅱ12, a hole Ⅲ13, a hole Ⅳ14, and a pin hole 15; the front end of the bobbin A2 is provided with a blind hole 16, the front outer ring is provided with a groove a, the rear of the bobbin A2 is provided with an axis hole Ⅰ17, and the upper surface of the bobbin A2 near the rear end is provided with a threaded hole 18, and the threaded hole 18 is connected with the axis hole Ⅰ17; the rear end of the rope 1 passes through the porcelain tube 7 fixed to the hole Ⅲ13, and bypasses the support pin 8 passing through the pin hole 15 and is fixed to the groove a of the bobbin A2; the rotating magnetic steel 5 Fixed in the blind hole 16 of the bobbin A2; screw I2 is threadedly connected to the threaded hole I23 of the motor assembly B through the hole I11 of the support plate A1 and the lower hole 36 of the housing B1, and the middle of the screw I2 is slidably connected to the lower hole 36; screw II4 is threadedly connected to the threaded hole II24 of the motor assembly B through the hole IV14 of the support plate A1 and the upper hole 38 of the housing B1, and the middle of the screw II4 is slidably connected to the upper hole 38; sensor I3 is fixed to the front end surface of the support plate A1; sensor II9 is ​​fixed to the lower end surface of the support plate A1;

[0007] The front end of the housing B1 in the motor assembly B is provided with a base II 35, a lower hole 36, an axial hole II 37 and an upper hole 38, and the upper part of the housing B1 is provided with a front lifting ear 39 and a rear lifting ear 40; the tail cover B2 is provided with a center hole 43, and the upper and lower sides of the front of the tail cover B2 are fixedly connected with a half ring III 41 and a half ring IV 42; the front end of the reducer 25 is fixedly connected with an output shaft 22; the motor 27 is provided with a lead 31; the reducer 25 is fixedly connected to the front end of the motor 27 through the riveting point 26 at the rear end; the upper and lower sides of the rear side of the housing of the motor 27 are fixedly connected with a half ring I 29 and a half ring II 30; the sleeve 28 is fixedly connected to the bottom of the housing B1; the upper spring 32 and the lower spring 33 The front ends are connected to the semi-ring Ⅰ29 and the semi-ring Ⅱ30 respectively, and the rear ends of the upper spring 32 and the lower spring 33 are connected to the semi-ring Ⅳ42 and the semi-ring Ⅲ41 respectively; the lead wire 31 is connected to the control circuit 34 through the center hole 43, and the control circuit 34 is also connected with the signal line Ⅰ19 and the signal line Ⅱ20, and the signal line Ⅰ19 and the signal line Ⅱ20 are connected to the sensor Ⅰ3 and the sensor Ⅱ9 respectively through the sleeve 28; the linear magnetic steel 21 is fixed to the base Ⅱ35; the front lifting ear 39 and the rear lifting ear 40 are used to fix the entire actuator; the control circuit 34 has a power supply, communication and sensor signal interface for processing signals and driving the motor 27 to rotate.

[0008] A rope tension control method based on the decoupled series elastic electric artificial muscle actuator is characterized by comprising the following steps:

[0009] 1. Set the target rope tension value;

[0010] 2. Read the linear Hall sensor signal and convert it into the axial displacement of the motor through the software algorithm. The actual tension value on the rope is calculated through the displacement and spring stiffness.

[0011] 3. Calculate the difference between the target tension value and the current tension value;

[0012] 4. Compare the difference between the actual tension value and the target tension value to determine the tension control mode. There are three situations:

[0013] 4.1 When the difference between the actual tension value and the target tension value is within the threshold range, the actuator enters the tension holding mode and brakes the motor to keep the motor rotor position stationary;

[0014] 4.2 The actual tension value is greater than the target tension value, and the difference is greater than the threshold value. The actuator enters the relaxation control mode, sets the driving duty cycle of the motor to the value calculated by the PID algorithm, and sets the rotation direction of the motor to the direction that stretches the driving rope, driving the motor to rotate;

[0015] 4.3 When the actual tension value is less than the target tension value and the difference is greater than the threshold value, the actuator enters the tension control mode, sets the driving duty cycle of the motor to the value calculated by the PID algorithm, and sets the rotation direction of the motor to the direction that shortens the driving rope, driving the motor to rotate;

[0016] 5 Return to step 1.

[0017] A rope length control method based on the decoupled series elastic electric artificial muscle actuator is characterized by comprising the following steps:

[0018] 1. Set the target rope length;

[0019] 2. Read the rotation Hall sensor signal and convert it into the absolute position of the spool through the software algorithm. The change in the absolute position of the spool is used to calculate the change in the rope length.

[0020] 3. Calculate the difference between the target rope length and the current rope length;

[0021] 4. Compare the difference between the actual rope length and the target rope length to determine the length control mode. There are three situations:

[0022] 4.1 When the difference between the actual rope length and the target rope length is within the threshold range, the actuator enters the length holding mode and brakes the motor to keep the motor rotor position stationary;

[0023] 4.2 The actual length is greater than the target length, and the difference is greater than the threshold value, the actuator enters the shortening control mode, sets the motor's driving duty cycle to the value calculated by the PID algorithm, and sets the motor's rotation direction to the direction that shortens the driving rope, driving the motor to rotate;

[0024] 4.3 When the actual length is less than the target length and the difference is greater than the threshold, the actuator enters the extension control mode, sets the driving duty cycle of the motor to the value calculated by the PID algorithm, and sets the rotation direction of the motor to the direction that causes the driving rope to extend, driving the motor to rotate;

[0025] 5 Return to step 1.

[0026] The beneficial effects of the present invention are:

[0027] 1. The decoupled series elastic electric artificial muscle actuator described in the present invention has a very high degree of integration and is fully functional. Compared with the traditional split-type rope-driven mechanism, it is easier to arrange and can be easily integrated into rope-driven exoskeletons, rope-driven robotic arms and other devices.

[0028] 2. The decoupled series elastic electric artificial muscle actuator described in the present invention has a built-in series elastic element and is also a series elastic actuator, which has better compliance than a direct drive actuator.

[0029] 3. The decoupled series elastic electric artificial muscle actuator described in the present invention has a shape and characteristics similar to natural muscles. By using this actuator, a rope-driven bionic robot can be developed by referring to the anatomical structure of organisms in nature.

[0030] 4. The decoupled series elastic electric artificial muscle actuator described in the present invention realizes rope tension measurement through Hall sensors, magnetic steel and springs. The measuring mechanism has a very long life and is not easily affected by environmental factors.

[0031] 5. The decoupled series elastic electric artificial muscle actuator described in the present invention realizes rope length measurement through Hall sensors, magnetic steel and springs. The measuring mechanism has a very long life and is not easily affected by environmental factors.

[0032] 6. The measurement direction of the rope tension measurement mechanism of the decoupled series elastic electric artificial muscle actuator described in the present invention is the same as the rope tension direction, and compared with similar devices, it has lower measurement error and hysteresis, which facilitates the realization of high-precision active rope tension control.

[0033] 7. The decoupled series elastic electric artificial muscle actuator described in the present invention has an active rope tension closed-loop control function, which can achieve accurate and rapid rope tension control and effectively avoid mechanism failure caused by rope slack.

[0034] 8. The decoupled series elastic electric artificial muscle actuator described in the present invention has a rope length closed-loop control function, which can achieve accurate and rapid rope length control, and can enable a robot equipped with the actuator to achieve accurate posture control.

[0035] 9. The size and specification of the elastic element of the decoupled series elastic electric artificial muscle actuator described in the present invention are less affected by the external dimensions of the actuator itself, and the design between the two can achieve decoupling. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a cross-sectional view of a decoupled series elastic electric artificial muscle actuator;

[0037] Figure 2 is a cross-sectional view of the winding assembly A;

[0038] Figure 3 is a cross-sectional view of the support plate A1;

[0039] Figure 4 is a cross-sectional view of the spool A2;

[0040] Figure 5 is a cross-sectional view of motor component B;

[0041] Figure 6 It is an axonometric view of the reducer 25 and the motor 27;

[0042] Figure 7 is a cross-sectional view of the housing B1;

[0043] Figure 8 is a cross-sectional view of the tail cover B2;

[0044] Fig. 9 This is the structural diagram of the rope tension control method;

[0045] Fig.10 is the state machine of the rope tension control method;

[0046] Fig.11 This is the structural diagram of the rope length control method;

[0047] Fig.12 is the state machine for the rope length control method;

[0048] Among them: A. Winding assembly A1. Support plate A2. Bobbin B. Motor assembly B1. Housing B2. Tail cover a. Groove 1. Rope 2. Screw I 3. Sensor I 4. Screw II 5. Rotating magnet 6. Bearing 7. Porcelain tube 8. Support pin

[0049] 9. Sensor II 10. Screw 11. Hole I 12. Hole II 13. Hole III 14. Hole IV 15. Pin hole 16. Blind hole 17. Shaft hole I 18. Threaded hole 19. Signal line I 20. Signal line II 21. Linear magnet 22. Output shaft 23. Threaded hole I 24. Threaded hole II 25. Reducer 26. Riveted point 27. Motor 28. Sleeve 29. Half ring I 30. Half ring II 31. Lead 32. Upper spring 33. Lower spring 34. Control circuit 35. Base II 36. Lower hole 37. Shaft hole II 38. Upper hole 39. Front lifting ear 40. Rear lifting ear 41. Half ring III 42. Half ring IV 43. Center hole DETAILED DESCRIPTION

[0050] The present invention is described below with reference to the accompanying drawings.

[0051] like Figures 1 to 4As shown, it is composed of a winding assembly A and a motor assembly B, and the winding assembly A and the motor assembly B are arranged front and back; the winding assembly A is composed of a support plate A1, a bobbin A2, a rope 1, a screw Ⅰ2, a sensor Ⅰ3, a screw Ⅱ4, a rotating magnetic steel 5, a bearing 6, a porcelain tube 7, a support pin 8, a sensor Ⅱ9, and a screw 10. The motor assembly B is composed of a housing B1, a tail cover B2, a signal line Ⅰ19, a signal line Ⅱ20, a linear magnetic steel 21, a threaded hole Ⅰ23, a threaded hole Ⅱ24, a reducer 25, and a riveting point 2 6. The motor 27, the sleeve 28, the upper spring 32, the lower spring 33 and the control circuit 34 are composed; the reducer 25, the motor 27, the upper spring 32 and the lower spring 33 are arranged from front to back and are located in the housing B1; the support plate A1 and the bobbin A2 are arranged front and back; the output shaft 22 of the reducer 25 is fixedly connected with the shaft hole Ⅰ17 of the bobbin A2 through the screw 10; the front end outer ring of the bobbin A2 is movably connected with the hole Ⅱ12 of the support plate A1 through the bearing 6; the rear outer ring of the bobbin A2 is connected with the shaft hole Ⅱ37 of the housing B1 Clearance fit; support plate A1 is provided with hole Ⅰ11, hole Ⅱ12, hole Ⅲ13, hole Ⅳ14, and pin hole 15; the front end of bobbin A2 is provided with blind hole 16, the front outer ring is provided with groove a, the rear of bobbin A2 is provided with shaft hole Ⅰ17, the upper surface of bobbin A2 near the rear end is provided with threaded hole 18, and the threaded hole 18 is connected with shaft hole Ⅰ17; the rear end of rope 1 passes through porcelain tube 7 fixedly connected to hole Ⅲ13, and bypasses support pin 8 passing through pin hole 15 and is fixedly connected to groove a of bobbin A2; rotating magnetic steel 5 is fixedly connected to bobbin A 2; screw Ⅰ2 is threadedly connected to threaded hole Ⅰ23 of motor assembly B through hole Ⅰ11 of support plate A1 and lower hole 36 of housing B1, and the middle of screw Ⅰ2 is slidably connected to lower hole 36; screw Ⅱ4 is threadedly connected to threaded hole Ⅱ24 of motor assembly B through hole Ⅳ14 of support plate A1 and upper hole 38 of housing B1, and the middle of screw Ⅱ4 is slidably connected to upper hole 38; sensor Ⅰ3 is fixedly connected to the front end surface of support plate A1; sensor Ⅱ9 is fixedly connected to the lower end surface of support plate A1;

[0052] like Figures 5 to 8As shown, the front end of the housing B1 in the motor assembly B is provided with a base II 35, a lower hole 36, an axis hole II 37 and an upper hole 38, and the upper part of the housing B1 is provided with a front ear 39 and a rear ear 40; the tail cover B2 is provided with a center hole 43, and the upper and lower sides of the front of the tail cover B2 are fixedly connected with a half ring III 41 and a half ring IV 42; the front end of the reducer 25 is fixedly connected with an output shaft 22; the motor 27 is provided with a lead 31; the reducer 25 is fixedly connected to the front end of the motor 27 through the riveting point 26 at the rear end; the upper and lower sides of the rear side of the housing of the motor 27 are fixedly connected with a half ring I 29 and a half ring II 30; the sleeve 28 is fixedly connected to the bottom of the housing B1; the upper spring 32 and the lower spring 33 The front end is connected to the semi-ring Ⅰ29 and the semi-ring Ⅱ30 respectively, and the rear ends of the upper spring 32 and the lower spring 33 are connected to the semi-ring Ⅳ42 and the semi-ring Ⅲ41 respectively; the lead 31 is connected to the control circuit 34 through the center hole 43, and the control circuit 34 is also connected with the signal line Ⅰ19 and the signal line Ⅱ20, and the signal line Ⅰ19 and the signal line Ⅱ20 are connected to the sensor Ⅰ3 and the sensor Ⅱ9 respectively through the sleeve 28; the linear magnetic steel 21 is fixed to the base Ⅱ35; the front lifting ear 39 and the rear lifting ear 40 are used to fix the entire actuator; the control circuit 34 has a power supply, communication and sensor signal interface for processing signals and driving the motor 27 to rotate.

[0053] like Fig. 9 As shown, the input of the rope tension control method of the present invention is "linear Hall sensor signal" and "rope tension request"; the linear Hall sensor signal changes with the tension in the current rope, and this signal is first calculated by the linear Hall sensor signal processing module to obtain the axial displacement of the motor, and then the axial displacement of the motor is obtained by the rope tension calculation module to obtain the actual measured value of the rope tension, and the measured value is compared with the rope tension request value, and the difference is input into the tension control strategy module. The rope tension value has only positive values, indicating the tension in the rope, but the tension difference can have positive or negative values, a positive value indicates that the target tension is greater than the current tension, and a negative value indicates that the target tension is less than the current tension. The tension control strategy module will output "motor rotation direction", "motor braking enable" and "motor drive current" according to the size of the tension difference, and provide these three values ​​to the motor drive circuit, and the drive circuit drives the motor.

[0054] like Fig.10As shown, the rope tension control strategy described in the invention is a finite state machine with three states, namely, tension holding mode, relaxation control mode and tension control mode. In the tension holding mode, the motor does not rotate; when the rope tension difference is less than the negative value of the relaxation threshold, the relaxation control mode is entered, at which time the motor rotates in the direction of rope elongation, and the motor drive current is determined by the PID algorithm, the input value of the PID algorithm is the absolute value of the rope tension difference, and the output value is the motor drive current; when the rope tension difference exceeds the positive value of the tension threshold, the tension mode is entered, at which time the motor rotates in the direction of rope shortening, and the motor drive current is determined by the PID algorithm, the input value of the PID algorithm is the rope tension difference, and the output value is the motor drive current.

[0055] The specific steps are:

[0056] 1. Set the target rope tension value;

[0057] 2. Read the linear Hall sensor signal and convert it into the axial displacement of the motor through the software algorithm. The actual tension value on the rope is calculated through the displacement and spring stiffness.

[0058] 3. Calculate the difference between the target tension value and the current tension value;

[0059] 4. Compare the difference between the actual tension value and the target tension value to determine the tension control mode. There are three situations:

[0060] 4.1 When the difference between the actual tension value and the target tension value is within the threshold range, the actuator enters the tension holding mode and brakes the motor to keep the motor rotor position stationary;

[0061] 4.2 The actual tension value is greater than the target tension value, and the difference is greater than the threshold value. The actuator enters the relaxation control mode, sets the driving duty cycle of the motor to the value calculated by the PID algorithm, and sets the rotation direction of the motor to the direction that stretches the driving rope, driving the motor to rotate;

[0062] 4.3 When the actual tension value is less than the target tension value and the difference is greater than the threshold value, the actuator enters the tension control mode, sets the driving duty cycle of the motor to the value calculated by the PID algorithm, and sets the rotation direction of the motor to the direction that shortens the driving rope, driving the motor to rotate;

[0063] 5 Return to step 1.

[0064] like Fig.11As shown, the input of the rope length control method of the present invention is "rotational Hall sensor signal" and "rope length request"; the rotational Hall sensor signal changes with the change of the bobbin angle. This signal is first calculated by the rotational Hall sensor signal processing module to obtain the bobbin rotation angle, and then the bobbin rotation angle is passed through the rope length calculation module to obtain the actual rope length, and the rope length measurement value is compared with the rope length request value, and the difference is input into the length control strategy module. The rope length value has only positive values, indicating the length of the rope outside the actuator, but the length difference can have positive or negative values. A positive value indicates that the target length is greater than the current length, and a negative value indicates that the target length is less than the current length. The length control strategy module will output "motor rotation direction", "motor brake enable" and "motor drive current" according to the size of the length difference, and provide these three values ​​to the motor drive circuit, and the drive circuit drives the motor.

[0065] like Fig.12 As shown, the rope length control strategy described in the invention is a finite state machine with three states, namely, length holding mode, elongation control mode and tension shortening control mode. In the length holding mode, the motor does not rotate; when the rope length difference is less than the negative value of the elongation threshold, the elongation control mode is entered, at which time the motor rotates in the direction of rope elongation, and the motor drive current is determined by the PID algorithm, the input value of the PID algorithm is the absolute value of the rope length difference, and the output value is the motor drive current; when the rope length difference exceeds the positive value of the shortening threshold, the shortening control mode is entered, at which time the motor rotates in the direction of rope shortening, and the motor drive current is determined by the PID algorithm, the input value of the PID algorithm is the rope length difference, and the output value is the motor drive current.

[0066] The specific steps are:

[0067] 1. Set the target rope length;

[0068] 2. Read the rotation Hall sensor signal and convert it into the absolute position of the spool through the software algorithm. The change in the absolute position of the spool is used to calculate the change in the rope length.

[0069] 3. Calculate the difference between the target rope length and the current rope length;

[0070] 4. Compare the difference between the actual rope length and the target rope length to determine the length control mode. There are three situations:

[0071] 4.1 When the difference between the actual rope length and the target rope length is within the threshold range, the actuator enters the length holding mode and brakes the motor to keep the motor rotor position stationary;

[0072] 4.2 The actual length is greater than the target length, and the difference is greater than the threshold value, the actuator enters the shortening control mode, sets the motor's driving duty cycle to the value calculated by the PID algorithm, and sets the motor's rotation direction to the direction that shortens the driving rope, driving the motor to rotate;

[0073] 4.3 When the actual length is less than the target length and the difference is greater than the threshold, the actuator enters the extension control mode, sets the driving duty cycle of the motor to the value calculated by the PID algorithm, and sets the rotation direction of the motor to the direction that causes the driving rope to extend, driving the motor to rotate;

[0074] 5 Return to step 1.

Claims

1. A decoupled series elastic electric artificial muscle actuator, characterized in that: The invention is composed of a winding assembly (A) and a motor assembly (B), which are arranged in front and back; the winding assembly (A) is composed of a support plate (A1), a bobbin (A2), a rope (1), a screw I (2), a sensor I (3), a screw II (4), a rotating magnetic steel (5), a bearing (6), a porcelain tube (7), a support pin (8), a sensor II (9), and a screw (10); the motor assembly (B) is composed of a housing (B1), a tail cover (B2), a signal line I (19), a signal line II (20), a linear magnetic steel (21), a threaded hole I (23), a threaded hole II (24), a reducer (25), a rivet point (26), a motor (27), a sleeve (28), an upper spring (32), a lower spring (33), and a control The invention comprises a circuit (34); a reducer (25), a motor (27), an upper spring (32) and a lower spring (33) arranged from front to back and located in a housing (B1); a support plate (A1) and a bobbin (A2) arranged front to back; an output shaft (22) of the reducer (25) is fixedly connected to an axial hole I (17) of the bobbin (A2) via a screw (10); a front end outer ring of the bobbin (A2) is movably connected to a hole II (12) of the support plate (A1) via a bearing (6); a rear outer ring of the bobbin (A2) is clearance-matched with an axial hole II (37) of the housing (B1); the support plate (A1) is provided with a hole I (11), a hole II (12), a hole III (13), a hole IV (14) and a pin hole (15); a blind hole (16) is provided at the front end of the bobbin (A2), and a The wire spool (A2) has a groove (a), an axial hole I (17) is provided at the rear of the wire spool (A2), a threaded hole (18) is provided on the upper surface near the rear end of the wire spool (A2), and the threaded hole (18) is connected with the axial hole I (17); the rear end of the rope (1) passes through the porcelain tube (7) fixedly connected to the hole III (13), and bypasses the support pin (8) passing through the pin hole (15) and is fixedly connected to the groove (a) of the wire spool (A2); the rotating magnetic steel (5) is fixedly connected to the blind hole (16) of the wire spool (A2); the screw I (2) is threadedly connected to the threaded hole I (23) of the motor component (B) through the hole I (11) of the support plate (A1) and the lower hole (36) of the housing (B1), and the middle part of the screw I (2) is slidably connected to the lower hole (36); the screw II (4) is threadedly connected to the lower hole (36) through the hole IV (14) of the support plate (A1) ) and the upper hole (38) of the housing (B1) are threadedly connected to the threaded hole II (24) of the motor assembly (B), and the middle part of the screw II (4) is slidably connected to the upper hole (38); the sensor I (3) is fixedly connected to the front end surface of the support plate (A1); the sensor II (9) is fixedly connected to the lower end surface of the support plate (A1); the front end of the housing (B1) of the motor assembly (B) is provided with a base II (35), a lower hole (36), an axis hole II (37) and an upper hole (38), and the upper part of the housing (B1) is provided with a front ear (39) and a rear ear (40); the tail cover (B2) is provided with a center hole (43), and the upper and lower sides of the front of the tail cover (B2) are fixedly connected with a half ring III (41) and a half ring IV (42); the front end of the reducer (25) is fixedly connected with an output shaft (22);The motor (27) is provided with a lead wire (31); the reducer (25) is fixedly connected to the front end of the motor (27) via a riveting point (26) at the rear end; a half ring I (29) and a half ring II (30) are fixedly connected to the upper and lower sides of the rear side of the housing of the motor (27); a sleeve (28) is fixedly connected to the lower side of the housing (B1); the front ends of the upper spring (32) and the lower spring (33) are respectively connected to the half ring I (29) and the half ring II (30); the upper spring (32) and the lower spring ( The rear ends of the lead wire (31) and the control circuit (34) are connected to the semi-ring IV (42) and the semi-ring III (41) respectively; the lead wire (31) is connected to the control circuit (34) through the central hole (43); the control circuit (34) is also connected to the signal wire I (19) and the signal wire II (20); the signal wire I (19) and the signal wire II (20) are connected to the sensor I (3) and the sensor II (9) respectively through the sleeve (28); the linear magnetic steel (21) is fixed to the base II (35).

2. The decoupled series elastic electric artificial muscle actuator according to claim 1, characterized in that: The sensor I (3) is a rotation angle Hall sensor, and the sensor II (9) is a linear Hall sensor; the signal line I (19) is a rotation angle Hall sensor signal line, and the signal line II (20) is a linear Hall sensor signal line.

3. A rope tension control method based on the decoupled series elastic electric artificial muscle actuator according to claim 1, characterized in that: The following steps are involved: 1) Set the target rope tension value; 2) Read the linear Hall sensor signal and convert it into the axial displacement of the motor through a software algorithm. The actual tension value on the rope is calculated through the displacement and spring stiffness; 3) Calculate the difference between the target tension value and the current tension value; 4) Compare the difference between the actual tension value and the target tension value to determine the tension control mode. There are three situations: 4.1) When the difference between the actual tension value and the target tension value is within the threshold range, the actuator enters the tension holding mode and brakes the motor to keep the motor rotor position stationary; 4.2) The actual tension value is greater than the target tension value, and the difference is greater than the threshold value, the actuator enters the relaxation control mode, sets the driving duty cycle of the motor to the value calculated by the PID algorithm, and sets the rotation direction of the motor to the direction that stretches the driving rope, driving the motor to rotate; 4.3) The actual tension value is less than the target tension value, and the difference is greater than the threshold value, the actuator enters the tension control mode, sets the driving duty cycle of the motor to the value calculated by the PID algorithm, and sets the rotation direction of the motor to the direction that shortens the driving rope, driving the motor to rotate; 5) Return to step 1).

4. A method for controlling the rope length of the decoupled series elastic electric artificial muscle actuator according to claim 1, characterized in that: The following steps are involved: 1) Set the target rope length; 2) Read the rotation Hall sensor signal and convert it into the absolute position of the spool through software algorithm. The change in the absolute position of the spool is used to calculate the change in the rope length. 3) Calculate the difference between the target rope length and the current rope length; 4) Compare the difference between the actual rope length and the target rope length to determine the length control mode. There are three situations: 4.1) When the difference between the actual rope length and the target rope length is within the threshold range, the actuator enters the length holding mode and brakes the motor to keep the motor rotor position stationary; 4.2) The actual length is greater than the target length, and the difference is greater than the threshold value, the actuator enters the shortening control mode, sets the driving duty cycle of the motor to the value calculated by the PID algorithm, and sets the rotation direction of the motor to the direction that shortens the driving rope, driving the motor to rotate; 4.3) The actual length is less than the target length, and the difference is greater than the threshold value, the actuator enters the extension control mode, sets the driving duty cycle of the motor to the value calculated by the PID algorithm, and sets the rotation direction of the motor to the direction that makes the driving rope extend, and drives the motor to rotate; 5) Return to step 1).

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