Orthosis wire driving device and control method thereof

Abstract

The invention discloses an orthosis wire driving device and a control method thereof.The orthosis wire driving device comprises a block orthosis and a wire driving unit, the wire driving unit is composed of a pulley block, a driving cable, a take-up device, a transmission device, a driving motor and a force sensor, the main body of the wire driving unit is divided into a left part and a right part, the take-up device, the transmission device and the driving motor are integrated on the driving side, the left side is the driven side, the force sensor is installed on the driven side and used for collecting correction force and conducting feedback control, the pulley blocks are arranged on the left part and the right part of the line driving unit, and the driving cable is jointly wound around the take-up device and the pulley blocks. And connecting the active side and the passive side. The orthodontic device is reasonable in structural design, has certain rigidity to provide enough orthodontic force for the spine with lateral protrusion, also has good compliance, and ensures the comfort of a patient in the wearing process.

Description

Technical Field

[0001] The present invention relates to the technical field of orthotics, and in particular to an orthotic wire driving device and a control method thereof. Background Art

[0002] Adolescent idiopathic scoliosis (AIS) refers to scoliosis caused by unknown reasons during the growth and development of adolescents. Orthosis treatment is a common treatment for scoliosis. However, traditional orthotics are usually made of nylon or hard plastic materials, with high overall hardness and poor compliance, resulting in low comfort when worn by patients, which has a certain impact on daily life. Therefore, with the advantages of adjustable shape and personalized customization, smart orthotics have become a research hotspot in recent years.

[0003] Most of the existing smart orthotics are driven by hydraulic linkage or pneumatic drive, and the overall structure is complex and bulky; while the wire drive is lightweight and portable, which is suitable for driving smart orthotics. To this end, we designed an orthosis wire drive device and its control method to solve the above problems. Summary of the invention

[0004] The purpose of the present invention is to solve the problems existing in the prior art, and to propose an orthosis wire drive device and a control method thereof, which has a certain rigidity, provides sufficient correction force for the spine with scoliosis, and also has good compliance to ensure the comfort of the patient during wearing.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A wire drive device for an orthosis comprises a block orthosis and a wire drive unit, wherein the wire drive unit is composed of a pulley block, a driving cable, a wire take-up device, a transmission device, a driving motor and a force sensor, wherein the wire drive unit is mainly divided into a left and a right part, wherein the right side is an active side, the wire take-up device, the transmission device and the driving motor are integrated in the active side, and the left side is a passive side, the force sensor is installed on the passive side, and is used for collecting the magnitude of the correction force and feedback control, the pulley block is arranged on the left and right parts of the wire drive unit, the driving cable is wound around the wire take-up device and the pulley block together, and the active side and the passive side are connected, and the driving motor drives the wire take-up device to take up and release the driving cable after deceleration through the transmission device, thereby changing the length of the driving cable between adjacent components of the block orthosis, so that the spacing between the left and right sides of the orthosis changes accordingly, and the tightness of the block orthosis is adjusted.

[0007] Preferably, the line drive unit comprises an active side base and a passive side base, and the active side base and the passive side base are respectively mounted at two ends of adjacent components of the block orthosis.

[0008] Preferably, the pulley block comprises a plurality of pulleys, wherein three pulleys are mounted on a passive side base, and two pulleys are mounted on an active side base. The pulley block as a whole is an axisymmetric structure, and the central pulley on the passive side base bears the main pulling force and is a force measuring pulley.

[0009] Preferably, the wire-taking device is composed of two wire-taking wheels, which have the same diameter and rotation speed and opposite rotation directions. One end of the driving cable passes through a through hole on one of the wire-taking wheels and is fixed to the wire-taking wheel in the form of a knot. As the wire-taking wheel rotates, it is wound and shortened. The other end of the driving cable passes around the remaining multiple pulleys and is fixed to another identical wire-taking wheel in the same way.

[0010] Preferably, the transmission device includes two parts: a worm gear transmission and a gear transmission. A worm is connected to the output shaft of the drive motor, and both of the two take-up wheels are connected to gears that rotate coaxially with them. One of the gears is connected to a worm wheel that rotates coaxially with it and meshes with the worm.

[0011] Preferably, the force sensor is connected to the force measuring pulley through a force measuring frame, and the force applied by the driving cable on the force measuring pulley is transmitted to the force measuring end of the force sensor. The axial hole of the force measuring frame is a straight slot, and the force measuring pulley can move along the slot in the force measuring direction, so that the force measuring pulley and the force sensor always maintain close contact. The main part of the force sensor is limited in its circumferential degree of freedom by the cylindrical structure on the left side of the force measuring frame. There are two M2 threaded holes on the force measuring end of the force sensor, which are fixed to the force measuring pulley by screws.

[0012] Preferably, a shell is arranged on the active side base, a boss is designed on the side wall of the shell, a worm hole is arranged on the worm, a worm support shaft extending into the worm hole and supporting the worm is arranged on the shell, threaded holes are arranged on both sides of the drive motor, the drive motor is mounted on the shell by M3 screws, a motor assembly hole is arranged on the shell, the output shaft of the drive motor passes through the motor assembly hole and cooperates with the worm, the worm and the output shaft of the drive motor are fixed by M4 top screws, a gear pin mounting hole is penetrated on the shell, the worm wheel and the gear are fixed by top screws and fixing pins, two protrusions are arranged on the inner wall of the shell, a plurality of shell connecting holes are penetrated on the active side base, and the bottom of the protrusion is provided with protrusions respectively matched with the plurality of shell connecting holes, the active side base and the side of the shell are both provided with mounting holes, and the active side base and the shell are fixed by screws.

[0013] Preferably, the driving motor is a stepping motor or a servo motor.

[0014] Preferably, pulley pin mounting holes are reserved on the active side base and the passive side base, and the pulley and the corresponding active side base and passive side base are fixed by elastic pins.

[0015] A control method for an orthosis wire drive device comprises the following steps:

[0016] S1, install the active side base and the passive side base on both sides of the block orthosis respectively, install the pulley and pin on the active side base and the passive side base, put the force sensor into the installation slot of the force measuring frame, and then fix the force measuring pulley on the passive side base with a pin, adjust the force measuring pulley to make it in close contact with the force sensor, and the installation of the left part of the line drive unit is completed;

[0017] S2, the right side needs to first fix the two take-up wheels with pins, install the drive motor on the right side housing with screws, and then fix the shaft and worm of the drive motor with top screws. The housing is assembled to the active side base as a whole, and the screws and nuts are installed through the mounting holes on the side to achieve fixation;

[0018] S3, winding the drive cable to complete the assembly of the line drive unit;

[0019] S4, after the drive motor is decelerated by the worm gear transmission, the amplified torque is output to the take-up wheel fixed with the drive cable, and the tension is transmitted to the block orthosis through the drive cable, so as to control the correction force and the deformation degree of the block orthosis, and adjust the tightness of the block orthosis.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The orthosis wire drive device is driven by a drive motor. After deceleration through a worm gear transmission, the amplified torque is output to a take-up wheel fixed with a drive cable. The drive cable is taken up and released to change the length of the drive cable between adjacent components of the block orthosis, so that the spacing between the left and right sides of the block orthosis changes accordingly, thereby adjusting the tightness of the orthosis.

[0022] 2. The wire drive unit of this orthosis can adjust the distance between the two parts of the block orthosis, and has force and displacement feedback control. The displacement control error does not exceed 0.5mm, and the force control accuracy is about 0.1N. It can meet the needs of intelligent orthosis to detect and regulate the size of correction force, and better balance the efficacy and comfort of orthosis in treating AIS. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1This is a schematic diagram of the connection between the block orthosis and the wire driving unit of the orthosis wire driving device proposed by the present invention;

[0024] Figure 2 This is a schematic diagram of the overall structure of a wire drive unit of an orthosis wire drive device proposed by the present invention;

[0025] Figure 3 It is a force analysis of a wire drive unit of a wire drive device for an orthosis proposed by the present invention;

[0026] Figure 4 This is a driving cable arrangement diagram of an orthosis wire driving device proposed by the present invention;

[0027] Figure 5 A schematic diagram of motion analysis of a wire drive device for an orthosis proposed by the present invention;

[0028] Figure 6 A schematic diagram of static analysis of a wire drive device for an orthosis proposed by the present invention;

[0029] Figure 7 This is a schematic diagram of the installation of a passive side base, a force sensor, and a force measuring frame of an orthosis wire drive device proposed by the present invention;

[0030] Figure 8 This is a schematic diagram of the connection between the active side base, the shell connection hole, and the pulley pin installation hole of the orthosis wire drive device proposed by the present invention;

[0031] Fig. 9 A schematic diagram of the connection of a housing, a worm support shaft, a motor assembly hole, and a gear pin mounting hole of an orthosis wire drive device proposed by the present invention;

[0032] Fig.10 This is a hardware connection diagram of a prototype of a wire drive unit of a wire drive device for an orthosis proposed in the present invention;

[0033] Fig.11 This is a schematic diagram of the interface of a motor control program for an orthosis wire drive device proposed by the present invention;

[0034] Fig.12 This is a schematic diagram of a force acquisition program interface of an orthosis wire drive device proposed by the present invention;

[0035] Fig.13 This is a schematic diagram of a force control method for an orthosis wire drive device proposed in the present invention.

[0036] In the figure: 1. block orthosis; 2. drive cable; 3. drive motor; 4. force sensor; 5. active side base; 6. passive side base; 7. pulley; 8. force measuring pulley; 9. take-up wheel; 10. worm; 11. gear; 12. worm wheel; 13. force measuring frame; 14. housing; 15. gear pin mounting hole; 16. worm support shaft; 17. motor assembly hole; 18. housing connection hole; 19. line drive unit; 20. pulley pin mounting hole. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0038] Reference Figure 1-Figure 13 A wire drive device for an orthosis includes a block orthosis 1 and a wire drive unit 19, wherein the wire drive unit 19 is composed of a pulley block, a drive cable 2, a wire take-up device, a transmission device, a drive motor 3 and a force sensor 4. The wire drive unit 19 is divided into two parts on the left and right sides, wherein the right side is an active side, the wire take-up device, the transmission device and the drive motor 3 are integrated on the active side, the drive motor 3 is a stepping motor or a servo motor, and the left side is a passive side. The force sensor 4 is installed on the passive side for collecting the magnitude of the correction force and feedback control. The pulley block is arranged on the left and right parts of the wire drive unit 19, the drive cable 2 is wound around the wire take-up device and the pulley block together, and the active side and the passive side are connected. After the drive motor 3 is decelerated by the transmission device, the wire take-up device is driven to take up and release the drive cable 2 to change the length of the drive cable 2 between the adjacent components of the block orthosis 1, so that the spacing between the left and right sides of the orthosis changes accordingly, thereby adjusting the tightness of the orthosis;

[0039] The line drive unit 19 includes an active side base 5 and a passive side base 6, and the active side base 5 and the passive side base 6 are respectively mounted at two ends of adjacent components of the block orthosis 1;

[0040] like Figure 4As shown, the pulley block includes a plurality of pulleys 7, wherein three pulleys 7 are mounted on the passive side base 6, and two pulleys 7 are mounted on the active side base 5. The pulley block is an axisymmetric structure as a whole. The pulley 7 in the center of the passive side base 6 bears the main tension as the force measuring pulley 8. It can be approximately regarded as a pulley block consisting of three movable pulleys and two fixed pulleys. Through simple analysis, it can be known that the pulley 7 in the center on the left side bears the main tension, and the rope tension is half of the tightening force on a single pulley, and the speed is about twice. The end of the driving cable 2 is fixed on the take-up device, which is driven by the driving motor 3. After deceleration through the worm gear 12 and the worm 10, the amplified torque is output to the take-up wheel 9 fixed with the driving cable 2, and the tension is transmitted to the block orthosis 1 through the driving cable 2, so as to realize the control of the correction force and the deformation degree of the orthosis.

[0041] The spacing and diameter of the multiple pulleys 7 are the same. When the take-up wheel 9 takes up the wire, the driving cables 2 between the two bases are always parallel to each other, which avoids the nonlinear change of the rope tension caused by the change of the base spacing. Since the overall size of the wire drive unit 19 is small and the force is not large, cotton thread is used as the driving cable 2, which can reduce the overall weight and improve the wearing comfort.

[0042] The wire-taking device is composed of two wire-taking wheels 9, which have the same diameter and rotation speed and opposite rotation directions. One end of the driving cable 2 passes through a through hole on one of the wire-taking wheels 9 and is fixed to the wire-taking wheel 9 in the form of a knot. As the wire-taking wheel 9 rotates and winds up, the other end of the driving cable 2 passes around the remaining multiple pulleys 7 and is fixed to another identical wire-taking wheel 9 in the same way.

[0043] like Figure 5 As shown, during the entire transmission process, the total length of the drive cable 2 remains unchanged. Assume that the length of the cable retracted when the take-up wheel rotates is ΔL, the length of the drive cable 2 between the pulleys is L1, the length of the drive cable 2 between the take-up wheel and the pulley is L2, and the distance d0 between the right pulley and the take-up wheel is a constant, then the total length is:

[0044] ∑L=2×(2L1+L2+ΔL)=2×(3L1+d0+ΔL)

[0045] Converting the take-up length into the angle θ of the take-up shaft rotation yields:

[0046]

[0047] The relationship between the distance change ΔL1 between the left and right sides of the orthosis and the rotation angle Δθ of the take-up wheel is:

[0048]

[0049] The transmission device includes two parts, a worm gear transmission and a gear transmission. A worm 10 is connected to the output shaft of the driving motor 3. Gears 11 coaxially rotating therewith are connected to the two take-up wheels 9. A worm wheel 12 coaxially rotating therewith and meshing with the worm 10 is connected to one of the gears 11. The output shaft of the driving motor 3 is connected to the worm 10 to transmit power to the worm wheel 12. The worm wheel 12 drives the coaxial gear 11 to rotate, thereby driving the remaining gears 11 and the take-up device on the gear 11 to rotate, thereby realizing the retraction and release of the drive cable 2. The worm gear is characterized in that it can realize self-locking, so that after the line drive unit 19 retracts the line to a specific position, the shape of the orthosis is maintained unchanged to provide correction force;

[0050] The maximum design correction force between orthoses is F = 300N, then the maximum design tension on the transmission cable is:

[0051]

[0052] The take-up stroke is L rope = 100 mm, and the two take-up wheels take up the wire at the same time. The minimum diameter of the take-up wheel is:

[0053]

[0054] The maximum tension on the take-up wheel is 1 / 6 of the correction force on the orthosis, so the torque required on the take-up wheel is:

[0055]

[0056] The maximum output torque of common small motors is between 0.02Nm and 0.7Nm, so it is estimated that the total transmission ratio i of the transmission mechanism is more appropriate in the range of 20-50;

[0057] In order to make the overall structure of the transmission mechanism smaller, the number of worm heads and the module are selected as the minimum values ​​in the standard series, the number of heads z1 = 1, the module m = 0.5; the pressure angle is the default 20°, and the table shows that the worm pitch circle diameter d1 = 9mm, the worm wheel pitch circle diameter d2 = mz2, z2 is the number of worm wheel teeth, and the transmission ratio of the worm transmission device generally prefers 10, 20, 40, 80 basic transmission ratios, and the preferred worm gear worm ratio i1 = 40, d2 = 20mm;

[0058] A pair of gears 11 driving the two take-up wheels 9 have the same number of teeth. The torque T output by the driving motor 3 is amplified by i1=40 after being decelerated by the worm wheel 12 and the worm 10. The worm wheel 12 transmits the torque to the coaxial driving wheel. Assume that the reduction ratio of the driving wheel and the driven wheel driven by the worm wheel 12 is i2. When the number of meshing gears n is an even number, the rotation directions of the gears on both sides are opposite. In order to make the overall structure of the line drive unit 19 smaller and more compact, and avoid the friction loss caused by multi-stage gear transmission, a pair of spur gears with the same number of teeth are used for transmission, and the transmission ratio i2=1. The gear pitch circle diameter is roughly the same as the take-up wheel diameter. Therefore, the number of teeth z1=z2=20 of the initial gear 11 is selected, and the pitch circle diameter d1=d2=mz=20mm.

[0059] The static analysis studies the relationship between the output torque of the drive motor 3 and the correction force of the linear drive unit 19, such as Figure 6 As shown, after the drive cable 2 is tensioned, since the drive cables 2 on both sides of the pulley always remain parallel, the tension on the drive cable 2 is always twice the pulling force on the pulley:

[0060] F 轮 =2F 绳

[0061] The torque on the take-up wheel and the rope tension satisfy the following relationship:

[0062]

[0063] The relationship between the take-up wheel torque and the correction force of the orthosis can be obtained as follows:

[0064]

[0065] like Figure 7 As shown, the force sensor 4 is connected to the force measuring pulley 8 through the force measuring frame 13, and the force of the driving cable 2 on the force measuring pulley 8 is transmitted to the force measuring end of the force sensor 4. The axial hole of the force measuring frame 13 is a straight slot of a cylindrical pin slide. The force measuring pulley 8 can move along the slot in the force measuring direction, so that the force measuring pulley 8 and the force sensor 4 always maintain close contact. The main part of the force sensor 4 is limited by the cylindrical structure on the left side of the force measuring frame 13. The force measuring end of the force sensor 4 has two M2 threaded holes, which are fixed to the force measuring pulley 8 by screws. The force measured on the force sensor 4 should be twice the tension on the line, and the correction force on both sides of the line drive unit 19 is 3 times the reading of the force sensor 4.

[0066] like Figure 8 As shown, pulley pin mounting holes 20 are reserved on both the active side base 5 and the passive side base 6, and the pulley 7 and the corresponding active side base 5 and passive side base 6 are fixed by elastic pins;

[0067] like Fig. 9 As shown, a shell 14 is arranged on the active side base 5, and the inner wall of the shell 14 has two protrusions, which can be used as a positioning reference when the shell 14 and the base are assembled on one hand, and can bear the gravity of the shell 14 on the other hand, greatly reducing the shear force between the screws and nuts connecting the shell 14 and the base. A plurality of shell 14 connecting holes 18 are opened through the active side base 5, and the bottom of the protrusion is provided with protrusions respectively matched with the plurality of shell connecting holes 18. The active side base 5 and the side of the shell 14 are both provided with mounting holes, and the active side base 5 and the shell 14 are fixed by screws. A boss is designed on the side wall of the shell 14, and a worm 10 is provided A worm hole, a worm support shaft 16 extending into the worm hole to support the worm 10 is provided on the housing 14, a gear pin mounting hole 15 is penetrated through the housing 14, the worm wheel 12 and the gear 11 are fixed by means of a top screw and a fixing pin, threaded holes are provided on both sides of the drive motor 3, the drive motor 3 is mounted on the housing 14 by means of M3 screws, a motor assembly hole 17 is provided on the housing 14, the output shaft of the drive motor 3 passes through the motor assembly hole 17 and cooperates with the worm 10, the worm 10 and the output shaft of the drive motor 3 are fixed by means of an M4 top screw, and the selection of the drive motor 3 includes the calculation of the maximum torque, the rated torque and the rated speed.

[0068] According to the above design and analysis, the total transmission ratio of the two-stage transmission is i=i1i2=40, the diameter of the take-up wheel is D=24.5mm, and the maximum correction force of the wire drive unit 19 is designed to be 300N. The tension on the single drive cable 2 is 50N, and the maximum torque required by the take-up wheel is:

[0069]

[0070] The maximum output torque required by the motor is calculated as:

[0071]

[0072] In order to retain a certain loading margin, the rated output torque of the motor should not be less than 0.02Nm.

[0073] The present invention also discloses a control method for an orthosis wire drive device, comprising the following steps:

[0074] S1, install the active side base 5 and the passive side base 6 on both sides of the block orthosis 1 respectively, pull the two sides of the block orthosis 1 close to each other, install the pulley 7 and the pin on the active side base 5 and the passive side base 6, put the force sensor 4 into the installation groove of the force measuring frame 13, and then fix the force measuring pulley 8 on the passive side base 6 with a pin, adjust the force measuring pulley 8 to make it in close contact with the force sensor 4, and the installation of the left part of the line drive unit 19 is completed;

[0075] S2, the right side part needs to first fix the two take-up wheels 9 with pins, and the drive motor 3 is installed on the right side housing 14 with screws, and then the shaft and worm 10 of the drive motor 3 are fixed with top screws, and the housing 14 is assembled to the active side base 5 as a whole, and the screws and nuts are installed through the side mounting holes to achieve fixation;

[0076] S3, winding the drive cable 2, completing the assembly of the line drive unit 19;

[0077] S4, after the driving motor 3 is decelerated through the worm gear 12 and the worm 10, the amplified torque is output to the take-up wheel 9 fixed with the driving cable 2, and the pulling force is transmitted to the block orthosis 1 through the driving cable 2, so as to control the size of the correction force and the degree of deformation of the block orthosis 1, and adjust the tightness of the block orthosis 1.

[0078] The working principle of the drive motor 3 is that the host computer sends a control signal to the driver through a communication line, and the driver converts the control signal into the power-on sequence of each phase winding of the drive motor 3, so that the motor rotates forward and reversely at a certain angle at a specific speed. The rotation speed is determined by the frequency of the control signal, and the rotation angle is determined by the number of control signal pulses. In addition, the step error will not produce an accumulation error. The control performance of the drive motor 3 is good. It can be quickly started, reversed and stopped according to the requirements of the input pulse signal within a certain frequency range, and the speed can be adjusted by changing the pulse frequency within a wide range. Another major feature of the drive motor 3 is that it can achieve high-precision angle and speed control without feedback, which simplifies the system and reduces costs, and is particularly suitable for open-loop numerical control systems.

[0079] The hardware connection of the line drive unit 19 is as follows Fig.10 As shown, the power module converts 0V AC power into 24V power for driving motor 3. The computer, as the host computer, converts the USB-A port into RS485 serial port through a serial port converter, or transmits the control signal to the driver through the sensor of the Ethercat bus. The driver controls the speed and angle of the motor according to the control signal from the host computer. The data signal of RS485 is transmitted in a differential manner using a pair of twisted pairs, namely A and B. When the level between A and B is positive, it indicates logic 1, and vice versa, it indicates logic 0. The differential transmission method of RS485 makes it highly anti-interference.

[0080] The driver is a key component that controls the movement of the drive motor 3. Under the control signal of the host computer, each phase winding is turned on and off in a certain order and time, and the motor is turned forward or reversed according to the command. The input end of the driver used in this article includes two pulse signals, two direction signals and two release signals, and the output end includes the positive pole of the power supply and the ground terminal, and the positive and negative poles of the motor A and B coils;

[0081] The line drive unit 19 uses a laptop as a host computer to control the drive motor 3. The two windings of the drive motor 3 are connected to the driver, and the driver is connected to the host computer through an RS485 to USB interface cable. The drive motor 3 is controlled by the control software on the computer to make the drive motor 3 work under the rated state. The control program interface is as follows Fig.11 As shown, after the motor operating parameters are set, the control program issues instructions to drive the drive motor 3 to rotate a specified number of circles at a set speed, and the number of revolutions less than one circle is controlled by the number of pulses in the circle.

[0082] The force sensor 4 converts the force signal into an electrical signal through a transmitter, and transmits the signal to the host computer through the RS485 serial port or the sensor of the Ethercat bus. The upper layer transmission protocol is Modbus. The force acquisition program in the host computer records the real-time force condition of the pressure sensor 4. The interface of the force acquisition program is as follows Fig.12 As shown, the force acquisition software has real-time force acquisition display and data export functions, and the sampling rate is 10Hz;

[0083] The wire drive unit 19 drives the cable 2 to change its length by driving the motor 3 (stepping motor or servo motor), and adjusts the spacing between the two parts of the wire drive to achieve the tightening or loosening of the wire drive unit 19. The tightening force of the wire drive is fed back through the force sensor 4 installed at the middle pulley, and the tightening force is controlled in a closed loop based on the admittance control principle. Suppose the tightening force command is F c , the actual feedback of force sensor 4 is F a , the line drive displacement instruction is X c , the actual displacement is X a , the linear drive stiffness coefficient is K (can be manually adjusted or experimentally measured), and the force control method based on admittance control is as follows: Fig.13 ;

[0084] The line drive unit 19 performs position control through a PID controller so that the actual displacement is the same as the displacement instruction, that is, X c -X a Close to 0. When there is a difference between the actual tightening force of the line drive and the command, a displacement command increment ΔX = (F a -F c ) / K, combined with the original displacement instruction as a new displacement instruction, that is, X c-new =X c +ΔX, when F a -F c and X c-new -X a When both are close to 0, the force control of the line drive unit 19 is completed, and at this time, the actual contraction force of the line drive unit 19 is equal to the command force.

[0085] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An orthosis wire drive device, comprising a block orthosis (1) and a wire drive unit (19), characterized in that: The wire drive unit (19) is composed of a pulley block, a drive cable (2), a wire take-up device, a transmission device, a drive motor (3) and a force sensor (4). The wire drive unit (19) is mainly divided into two parts, the right side is the active side, the wire take-up device, the transmission device and the drive motor (3) are integrated on the active side, and the left side is the passive side. The force sensor (4) is installed on the passive side and is used to collect the magnitude of the correction force and feedback control. The pulley block is arranged on the left and right parts of the wire drive unit (19). The drive cable (2) is wound around the wire take-up device and the pulley block together to connect the active side and the passive side. The drive motor (3) drives the wire take-up device to take up and release the drive cable (2) after deceleration through the transmission device, thereby changing the length of the drive cable (2) between adjacent components of the block orthosis (1), so that the spacing between the left and right sides of the orthosis changes accordingly, thereby adjusting the tightness of the block orthosis (1).

2. The orthosis wire driving device according to claim 1, characterized in that: The line drive unit (19) comprises an active side base (5) and a passive side base (6), and the active side base (5) and the passive side base (6) are respectively mounted at two ends of adjacent components of the block orthosis (1).

3. The orthosis wire driving device according to claim 2, characterized in that: The pulley block comprises a plurality of pulleys (7), wherein three of the pulleys (7) are mounted on a passive side base (6), and two pulleys (7) are mounted on an active side base (5); the pulley block as a whole is an axisymmetric structure, and the pulley (7) in the middle of the passive side base (6) that bears the main pulling force is a force measuring pulley (8).

4. The orthosis wire driving device according to claim 3, characterized in that: The wire-taking device is composed of two wire-taking wheels (9), the two wire-taking wheels (9) have the same diameter and rotation speed and rotate in opposite directions, one end of the driving cable (2) passes through a through hole on one of the wire-taking wheels (9) and is fixed to the wire-taking wheel (9) in the form of a knot, and as the wire-taking wheel (9) rotates and is wound and shortened, the other end of the driving cable (2) passes around the remaining plurality of pulleys (7) and is fixed to another identical wire-taking wheel (9) in the same way.

5. The orthosis wire driving device according to claim 1, characterized in that: The transmission device comprises two parts, a worm gear transmission and a gear transmission. A worm (10) is connected to the output shaft of the drive motor (3). The two take-up wheels (9) are both connected to gears (11) that rotate coaxially with the take-up wheels. One of the gears (11) is connected to a worm gear (12) that rotates coaxially with the take-up wheels and meshes with the worm (10).

6. The orthosis wire driving device according to claim 3, characterized in that: The force sensor (4) is connected to the force measuring pulley (8) through the force measuring frame (13), and the force acting on the force measuring pulley (8) by the driving cable (2) is transmitted to the force measuring end of the force sensor (4). The axial hole of the force measuring frame (13) is a straight slot, and the force measuring pulley (8) can move along the slot in the force measuring direction, so that the force measuring pulley (8) and the force sensor (4) always maintain close contact. The main part of the force sensor (4) is limited in its circumferential degree of freedom by the cylindrical structure on the left side of the force measuring frame (13). The force measuring end of the force sensor (4) has two M2 threaded holes, which are fixed to the force measuring pulley (8) by screws.

7. The orthosis wire driving device according to claim 5, characterized in that: The active side base (5) is provided with a housing (14), a boss is designed on the side wall of the housing (14), a worm hole is provided on the worm (10), a worm support shaft (16) is provided on the housing (14) and extends into the worm hole to support the worm (10), threaded holes are provided on both sides of the drive motor (3), the drive motor (3) is mounted on the housing (14) by means of M3 screws, a motor assembly hole (17) is provided on the housing (14), an output shaft of the drive motor (3) passes through the motor assembly hole (17) to cooperate with the worm (10), and the worm (10) and the drive motor are connected. The output shaft of the gear (3) is fixed by an M4 top screw, the housing (14) is provided with a gear pin mounting hole (15), the worm wheel (12) and the gear (11) are fixed by a top screw and a fixing pin, the inner wall of the housing (14) has two protrusions, the active side base (5) is provided with a plurality of housing connection holes (18), the bottom of the protrusion is provided with protrusions respectively matched with the plurality of housing connection holes (18), the side edges of the active side base (5) and the housing (14) are provided with mounting holes, and the active side base (5) and the housing (14) are fixed by screws.

8. The orthosis wire driving device according to claim 1, characterized in that: The driving motor (3) is a stepping motor or a servo motor.

9. The orthosis wire driving device according to claim 1, characterized in that: Pulley pin mounting holes (20) are reserved on the active side base (5) and the passive side base (6), and the pulley (7) and the corresponding active side base (5) and passive side base (6) are fixed by elastic pins.

10. A control method for an orthosis wire driving device, used for controlling an orthosis wire driving device according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1, install the active side base (5) and the passive side base (6) on both sides of the block orthosis (1), install the pulley (7) and the pin on the active side base (5) and the passive side base (6), put the force sensor (4) into the installation groove of the force measuring frame (13), and then fix the force measuring pulley (8) on the passive side base (6) with a pin, adjust the force measuring pulley (8) so that it is in close contact with the force sensor (4), and thus complete the installation of the left part of the line drive unit (19); S2, the right side part needs to first fix the two take-up wheels (9) with pins, and the drive motor (3) is installed on the right side housing (14) with screws, and then the shaft and worm (10) of the drive motor (3) are fixed with top screws, and the housing (14) is assembled to the active side base (5) as a whole, and screws and nuts are inserted through the side mounting holes to achieve fixation; S3, winding the drive cable (2) to complete the assembly of the line drive unit (19); S4, after the driving motor (3) is decelerated through the worm gear (12) and the worm (10), the amplified torque is output to the take-up wheel (9) fixed with the driving cable (2), and the pulling force is transmitted to the block orthosis (1) through the driving cable (2), so as to control the magnitude of the correction force and the degree of deformation of the block orthosis (1), and adjust the tightness of the block orthosis (1).

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