CN117656100B - Motion axis adaptive ankle joint motion robot and control method thereof - Google Patents

Abstract

The present invention provides a motion axis adaptive ankle joint motion robot and a control method thereof, which relate to the field of motion robots. The motion robot comprises an axis compensation component, a rope retracting component, a pulley deflection component, a support component, a fixed pulley and a rope. The axis compensation component, the rope retracting component, the pulley deflection component, the fixed pulley and the rope are all arranged in the support component, and the rope retracting component, the pulley deflection component and the fixed pulley are all symmetrically arranged on both sides of the axis compensation component. The present invention realizes the fitting of the motion axis of the ankle joint with the motion axis of the robot through a double fork arm mechanism and a spring to avoid injuries during the motion process. Through the rope retracting component, the elongation and shortening of the rope can be accurately controlled through the rotation angle of the motor. Through the pulley deflection component, the friction between the rope and the pulley is reduced, and the direction of the rope is easy to change. Through the cooperation of the components, various movements of the ankle joint can be realized.

Description

Motion axis adaptive ankle joint motion robot and control method thereof

Technical Field

The invention relates to the field of motion robots, and in particular to a motion axis adaptive ankle joint motion robot and a control method thereof.

Background technique

To avoid injuries to the ankle joint during exercise, most ankle joint motion robots are currently studied based on a fixed rotation axis, which makes it difficult to achieve consistency between the biological rotation center and the robot's rotation center. During ankle joint movement, the motion axis is constantly changing, and simple rigid equivalence is difficult to achieve coincidence with the human body's motion axis. In addition, the rigid mechanism has a large inertial impact and poor compliance, and the rigid connecting rod is prone to harmful impact during exercise training.

Chinese patent application CN201210555816.1 discloses an exoskeleton robot for lower limb exercise training and its motion control method, the robot includes a support balance frame, an exoskeleton mechanical leg, a treadmill and a control system; the motion control method provides two modes, namely passive walking motion and active walking motion mode: in the passive walking motion mode, the robot is controlled to drive the operator to complete a specific movement or move in a correct physiological gait trajectory; in the active walking motion mode, the robot suppresses the operator's limited abnormal movement, directly corrects or generates the operator's desired gait training trajectory through an adaptive controller, and indirectly achieves the purpose of the robot providing walking motion auxiliary force and impedance force. However, the patent application cannot fully carry out the changes in the ankle joint during the movement, and cannot achieve the coincidence of the robot's motion axis with the biological motion axis.

Therefore, it is necessary to propose an ankle joint motion robot with adaptive motion axis and a control method thereof to automatically compensate the axis and adapt to the changes of the axis during the motion process.

Summary of the invention

In view of the problems existing in the prior art, the present invention provides an ankle joint motion robot with adaptive motion axis and a control method thereof. The motion axis of the ankle joint is fitted with the motion axis of the robot through a double-wishbone mechanism and a spring to avoid injuries during movement. The rope retraction and release assembly is used to accurately control the elongation and shortening of the rope through the rotation angle of the motor. The pulley deflection assembly is used to reduce the friction between the rope and the pulley, making it easier to change the direction of the rope. The dorsiflexion/plantar flexion, inversion/eversion, and internal rotation/external rotation of the ankle joint are achieved through the cooperation of the components, thereby performing motion training on the ankle joint.

The present invention provides a motion axis adaptive ankle joint motion robot, which comprises an axis compensation component, a rope retracting and releasing component, a pulley deflection component, a support component and a rope; the axis compensation component comprises a pillar, a fixing sleeve, a double fork arm mechanism, a rotating frame, a spring, a pedal connecting frame, a pedal slide rail, a pedal, a knob and a posture sensor, the pillars are symmetrically arranged in the support component, the first end face of the pillars is connected to the bottom plate of the support component, the fixing sleeve is connected to the second end face of the pillars, both sides of the rotating frame are rotatably connected to the fixing sleeve through the double fork arm mechanism, the first end of the spring is fixedly connected to the rotating frame, The second end of the spring is rotatably connected to the support arm of the pedal connecting frame, and pedal slide rails are symmetrically arranged on both sides of the support plate of the pedal connecting frame. The pedal is slidably connected to the pedal slide rails, the knob passes through the pedal slide rails and is threadedly connected to the pedal, and the posture sensor is connected to the pedal; the rope retracting assembly is arranged on the bottom plate, and the rope retracting assembly includes a motor, a drum shaft, a drum, a first gear, a gear frame, a second gear, a gear shaft, a third gear, a cam member, a fourth gear, a guide rod and a synchronous block. The first rotating shaft of the drum shaft is connected to the output shaft of the motor through a coupling, and the drum is slidably connected to the guide shaft of the drum shaft. The second rotating shaft of the reel shaft is rotatably connected to the base plate through a bearing seat, the first gear is connected to the first rotating shaft of the reel shaft, the gear frame is arranged on one side of the reel, the second gear is rotatably connected to the gear frame through the gear shaft, and the second gear is meshed with the first gear for transmission, the third gear is connected to the gear shaft, the camshaft of the cam member is rotatably connected to the gear frame, the fourth gear is connected to the camshaft, and the fourth gear is meshed with the third gear for transmission, the guide rod is arranged on one side of the cam member, and both ends of the guide rod are connected to the gear frame, the slider of the synchronization block is slidably connected to the guide rod, and the cylindrical guide of the synchronization block The block is slidably connected to the cam groove of the cam member, and the driving block of the synchronous block is slidably connected to the reel; the pulley deflection assembly includes a support seat, a bearing block, a swinging member, a swinging pulley, a rack, a tension spring seat and a tension spring, the bearing block is connected to the first end face of the support seat, the swinging member is rotatably connected to the bearing block, the swinging member is slidably connected to the slide groove of the support seat, the swing pulley is arranged in the middle position of the swinging member, the rack is arranged on the support seat through the rack seat, and the rack and the rack seat are slidably connected, the rack and the swinging member are meshed for transmission, the first end of the tension spring is connected to the rack through the tension spring seat, and the second end of the tension spring is connected to the rack seat.

Preferably, the supporting assembly includes a base plate, a frame, a top plate, a leg bracket, a leg protector and a universal wheel, the first end surface of the frame is connected to the first end surface of the base plate, the first end surface of the top plate is connected to the second end surface of the frame, the leg bracket is connected to the second end surface of the top plate, the leg protector is connected to the leg bracket, and the universal wheel is arranged at the four corners of the second end surface of the base plate.

Preferably, the double fork arm mechanism includes an arm support, a first fork arm, a second fork arm, a movable seat and a damper, the arm support is connected to the fixed sleeve, the first ends of the first fork arm and the second fork arm are both rotatably connected to the arm support, the second ends of the first fork arm and the second fork arm are both rotatably connected to the movable seat, and the first fork arm and the second fork arm are arranged in parallel, the first end of the damper is rotatably connected to the arm support, and the second end of the damper is rotatably connected to the movable seat.

Preferably, the number of pulley deflection assemblies, rope retracting assemblies and ropes is the same, four groups of rope retracting assemblies are respectively arranged at the four corners of the base plate, at least two groups of rope retracting assemblies are symmetrically and obliquely arranged on the base plate, at least four groups of pulley deflection assemblies are arranged on the top plate, and at least two groups of pulley deflection assemblies are symmetrically arranged on the base plate; fixed pulleys are also arranged at the four corners of the base plate, the first ends of at least four groups of ropes are wound around the drums of the rope retracting assemblies at the four corners, the second ends of the four groups of ropes are successively bypassed around the fixed pulley and the swinging pulley of the pulley deflection assembly at the top plate position and are connected to the support plate of the pedal connecting frame, the first ends of at least two groups of ropes are wound around the drums of the inclined rope retracting assemblies, the second ends of the two groups of ropes are bypassed around the swinging pulley of the pulley deflection assembly arranged on the base plate and are connected to the support plate of the pedal connecting frame.

Preferably, the reel shaft includes a rotating disk, a guide shaft, a first rotating shaft and a second rotating shaft, the guide shaft is distributed circumferentially between the two rotating disks, the first rotating shaft and the second rotating shaft are both connected to the rotating disk, and the axes of the rotating disk, the guide shaft, the first rotating shaft and the second rotating shaft are the same.

Preferably, the cam member comprises a cam, a cam groove and a cam shaft, the cam groove is circumferentially arranged on the cam, and the cam shaft is arranged at two ends of the cam.

Preferably, the synchronization block includes a slider, a cylindrical guide block and a driving block, the cylindrical guide block is arranged on the first end face of the slider, and the contact end with the cam groove in the cam member is hemispherical, the driving block is arranged on the second end face of the slider, an arc-shaped groove is arranged on one side of the reel, and the driving block is slidably connected to the arc-shaped groove.

Preferably, the swing member includes a swing block, a fifth gear and a rotating shaft, the swing block is slidably connected to the slide groove of the support seat, the fifth gear is arranged on one side of the swing block, and the fifth gear is meshed with the rack for transmission, the rotating shaft is arranged in the middle of the second end surface of the swing block, the rotating shaft is rotatably connected to the bearing block, and the axis of the rotating shaft coincides with the pulley tangent of the swing pulley.

Preferably, the pedal connecting frame includes a support arm and a support plate, the support arm and the support plate are vertically arranged, a through hole is provided at the end of the support arm to be connected to the bearing of the axis compensation assembly, slots are provided at the four corners of the support plate, and the rope is connected to the support plate through the slots; hollow cylinders are symmetrically arranged at the end positions of both sides of the rotating frame, and a solid cylinder is arranged on the movable seat, and the inner side of the hollow cylinder is rotatably and slidably connected to the solid cylinder.

A second aspect of the present invention provides a control method for the aforementioned motion axis adaptive ankle joint motion robot, comprising the following steps:

S1. Place the foot on the pedal and fix it to the pedal with a bandage. Adjust the distance between the pedal and the rotating frame with a knob so that the axis of the ankle joint coincides with the axis of rotation of the rotating frame. Then fix the leg to the leg protector with a bandage.

S2. Establish a global coordinate system and a local coordinate system respectively. Take the center point of the line connecting the bottoms of the two side pillars as the origin O to establish a global coordinate system OX _b Y _b Z _b ; take the center of the pedal semicircle as the coordinate origin Q to establish a local coordinate system QX _a Y _a Z _a ; take the intersection of the rotation axis of the rotating frame and the axis of the bearing as the coordinate origin P to establish a local coordinate system PXYZ ; Ai is the connection point between the rope Li and the moving platform, Bi _is the connection point between the rope Li and the swing _pulley , where i = 1, 2, 3 _, 4, 5 _, 6;

S3. Based on the local coordinate system, the pedal's rotation angle α around the X axis, the rotation angle β around the Y axis, and the rotation angle γ around the Z axis are used to describe the pedal's position and posture using the ZYX _Euler angle . Then the rotation matrix of the local coordinate system QXaYaZa _relative to the local coordinate system PXYZ _is ^P R _Q ;

S4. According to the geometric characteristics and the vector parallelogram, the length of each rope l _i is expressed by the relationship between the rope connection point and the coordinate point. The specific expression is as follows:

, where i = 1, 2, 3, 4, 5, 6;

In the formula, l _i represents the length of each rope, represents the position vector from point A _i to point B _i ,/> represents the position vector from _point Bi to the origin P ,/> represents the position vector from the origin Q to the origin P ,/> Represents the position vector from point A _i to the origin Q ;

S5. Substituting each parameter point into the expression of rope length l _i , the specific relationship between each rope length and the pedal rotation angle can be obtained;

S6. Rotate the pedal to the required angle. According to the specific relationship value obtained, the controller controls the rotation angle of each motor to lengthen or shorten each rope to realize the rotation of the pedal around the axis. The posture data of the pedal can be monitored in real time by the posture sensor and fed back to the controller to adjust the extension and retraction of each motor in real time.

The characteristics and beneficial effects of the present invention are:

1. The motion axis adaptive ankle joint motion robot of the present invention compensates the motion axis in real time through the double fork arm mechanism in the axis compensation component, so as to achieve the fitting of the motion axis of the ankle joint with the motion axis of the robot, thereby avoiding the ankle joint from being damaged during the motion process.

2. The motion axis adaptive ankle joint motion robot of the present invention is powered by a rope retracting and releasing assembly to rotate the rope traction pedal with a small impact inertia. The human leg is fixed by a leg protector. Through the cooperation of various components, the dorsiflexion/plantar flexion, inversion/eversion, internal rotation/external rotation of the ankle joint are achieved, thereby performing motion training on the ankle joint.

3. The motion axis adaptive ankle joint motion robot of the present invention realizes the movement of the drum while rotating through the rope retracting and releasing assembly, so that the rope is evenly wound on the drum, avoiding the rope winding disorder caused by the vibration during the winding of the rope, and realizing the accurate calculation and control of the elongation and shortening of the rope through the rotation angle of the motor.

4. The motion axis adaptive ankle joint motion robot of the present invention uses a pulley deflection assembly. When the driving rope rotates the pedal, the fixed pulley adaptively rotates and adapts to the direction of the rope, thereby reducing the friction between the rope and the pulley and ensuring that the rope changes direction more easily.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the overall structure of a motion axis adaptive ankle joint motion robot according to the present invention;

FIG2 is a schematic diagram of the structure of the central axis compensation assembly of the present invention;

FIG3 is a schematic structural diagram of a double fork arm mechanism in the present invention;

FIG4 is a schematic diagram of the structure of the rope retracting assembly of the present invention;

FIG5 is a schematic front view of a pulley deflection assembly in the present invention;

FIG6 is a schematic diagram of the structure of the pulley deflection assembly of the present invention;

FIG7 is a schematic diagram of the position of the rope retracting assembly in the present invention;

FIG8 is a schematic diagram of a force analysis of a pulley deflection assembly in the present invention;

FIG9 is a schematic diagram of the overall force analysis of the present invention;

10 is a schematic left view of the overall force analysis of the present invention;

FIG11 is a schematic diagram of a geometric model of the present invention;

12a-12c are schematic diagrams of angle variation curves of ropes and pedals in the present invention;

13a to 13f are schematic diagrams of the composite motion change curves of the driving ropes and pedals around the X -axis and the Y- axis in the present invention.

Main reference numerals:

1. Axis compensation assembly; 101. Pillar; 102. Fixed sleeve; 103. Double fork arm mechanism; 1031. Arm support; 1032. First fork arm; 1033. Second fork arm; 1034. Moving seat; 1035. Damper; 104. Rotating frame; 105. Spring; 106. Spring seat; 107. Bearing; 108. Snap ring; 109. Pedal connecting frame; 1091. Support arm; 1092. Support plate; 110. Pedal slide rail; 111. Pedal; 112. Knob; 113. Posture sensor; 2. Rope retracting assembly; 21. Rope retracting assembly A; 22. Rope retracting assembly B; 23. Rope retracting assembly C; 24. Rope retracting assembly D; 25. Rope retracting assembly E, 26. Rope retracting assembly F; 201, motor bracket; 202, motor; 203, reel shaft; 2031, rotating disk; 2032, guide shaft; 2033, first rotating shaft; 2034, second rotating shaft; 204, coupling; 205, reel; 206, bearing seat; 207, first gear; 208, gear rack; 209, second gear; 210, gear shaft; 211, third gear; 212, cam member; 2121, cam; 2122, cam groove; 2123, cam shaft; 213, fourth gear; 214, guide rod; 215. Synchronous block; 2151. Sliding block; 2152. Cylindrical guide block; 2153. Driving block; 3. Pulley deflection assembly; 31. Support seat; 32. Bearing block; 33. Swinging member; 331. Swinging block; 332. Fifth gear; 333. Rotating shaft; 34. Swinging pulley; 35. Rack seat; 36. Rack; 37. Tension spring seat; 38. Tension spring; 4. Support assembly; 41. Bottom plate; 42. Frame; 43. Top plate; 44. Leg bracket; 45. Leg protector; 46. Universal wheel; 5. Fixed pulley; 6. Rope.

Detailed ways

In order to fully describe the technical content, structural features, objectives and effects of the present invention, the following will be described in detail with reference to the accompanying drawings.

The present invention provides a motion axis adaptive ankle joint motion robot, as shown in FIG1, which includes an axis compensation component 1, a rope retracting component 2, a pulley deflection component 3, a support component 4, a fixed pulley 5 and a rope 6. The axis compensation component 1, the rope retracting component 2, the pulley deflection component 3, the fixed pulley 5 and the rope 6 are all arranged in the support component 4, and the rope retracting component 2, the pulley deflection component 3 and the fixed pulley 5 are symmetrically arranged on both sides of the axis compensation component 1. The support component 4 includes a bottom plate 41, a frame 42, a top plate 43, a leg bracket 44, a leg guard 45 and a universal wheel 46. The first end face of the frame 42 is connected to the first end face of the bottom plate 41, the first end face of the top plate 43 is connected to the second end face of the frame 4, the leg bracket 44 is connected to the second end face of the top plate 43, the leg guard 45 is connected to the leg bracket 44, and the universal wheel 46 is arranged at the four corners of the second end face of the bottom plate 41.

As shown in Figures 2 and 3, the axis compensation component 1 includes a pillar 101, a fixed sleeve 102, a double fork arm mechanism 103, a rotating frame 104, a spring 105, a spring seat 106, a bearing 107, a retaining ring 108, a pedal connecting frame 109, a pedal slide rail 110, a pedal 111, a knob 112 and a posture sensor 113. The pillar 101 is symmetrically arranged in the support component 4, the first end face of the pillar 101 is connected to the bottom plate 41 of the support component 4, the fixed sleeve 102 is connected to the second end face of the pillar 101, and both sides of the rotating frame 104 are connected to the double fork arm mechanism 103. The fixing sleeve 102 is rotatably connected, the first end of the spring 105 is fixedly connected to the rotating frame 104, the second end of the spring 105 is connected to the spring seat 106, the spring seat 106 is rotatably connected to the support arm 1091 of the pedal connecting frame 109 through the bearing 107 and the retaining ring 108, and the pedal slide rails are symmetrically arranged on both sides of the support plate of the pedal connecting frame, that is, the pedal slide rails 110 are symmetrically arranged on both sides of the support plate 1092 of the pedal connecting frame 109, the pedal 111 is slidably connected to the pedal slide rail 110, and the knob 112 passes through the pedal slide rail 110 and is threadedly connected to the pedal 111, The sensor 113 is connected to the pedal 111; the double fork arm mechanism 103 includes an arm support 1031, a first fork arm 1032, a second fork arm 1033, a movable seat 1034 and a damper 1035, the arm support 1031 is connected to the fixed sleeve 102, the first ends of the first fork arm 1032 and the second fork arm 1033 are both rotatably connected to the arm support 1031, the second ends of the first fork arm 1032 and the second fork arm 1033 are both rotatably connected to the movable seat 1034, and the first fork arm 1032 and the second fork arm 1033 are arranged in parallel, and the first end of the damper 1035 is connected to the arm support 1 031 is rotatably connected, and the second end of the damper 1035 is rotatably connected to the moving seat 1034; the pedal connecting frame 109, which includes a support arm 1091 and a support plate 1092, the support arm 1091 and the support plate 1092 are vertically arranged, the end of the support arm 1091 is provided with a through hole connected to the bearing 107, and slots are provided at the four corners of the support plate 1092, and the rope 6 is connected to the support plate 1092 through the slots; hollow cylinders are symmetrically arranged at the end positions of both sides of the rotating frame 104, and the moving seat 1034 is provided with a solid cylinder, and the inner side of the hollow cylinder is rotatably and slidably connected to the solid cylinder.

As shown in FIG4 , the rope retracting assembly 2 is arranged on the base plate 41, and the rope retracting assembly 2 includes a motor bracket 201, a motor 202, a drum shaft 203, a coupling 204, a drum 205, a bearing seat 206, a first gear 207, a gear frame 208, a second gear 209, a gear shaft 210, a third gear 211, a cam member 212, a fourth gear 213, a guide rod 214 and a synchronization block 215. The motor bracket 201 is connected to the base plate 41 of the support assembly 4, the mounting end of the motor 202 is connected to the motor bracket 201, the first rotating shaft 2033 of the drum shaft 203 is connected to the output shaft of the motor 202 through the coupling 204, the drum 205 is slidably connected to the guide shaft 2032 of the drum shaft 203, the second rotating shaft of the drum shaft is rotationally connected to the base plate through the bearing seat, that is, the bearing seat 206 is rotationally connected to the second rotating shaft 2034 of the drum shaft 203, and the fixed end of the bearing seat 206 is connected to the base plate 41. The first gear 207 is connected to the first rotating shaft 2033 of the reel shaft 203, the gear frame 208 is arranged at a side position of the reel 205 and is connected to the bottom plate 41, the second gear 209 is rotatably connected to the gear frame 208 through the gear shaft 210, and the second gear 209 is meshed with the first gear 207 for transmission, the third gear 211 is connected to the gear shaft 210, the cam shaft 2123 of the cam member 212 is rotatably connected to the gear frame 208, the fourth gear 213 is connected to the cam shaft 2123, and the fourth gear 213 is meshed with the third gear 211 for transmission, the guide rod 214 is arranged at a side position of the cam member 212, and the two ends of the guide rod 214 are connected to the gear frame 208, the slider 2151 of the synchronization block 215 is slidably connected to the guide rod 214, the cylindrical guide block 2152 of the synchronization block 215 is slidably connected to the cam groove 2122 of the cam member 212, and the driving block 2153 of the synchronization block 215 is slidably connected to the reel 205. The reel shaft 203 includes a rotating disk 2031, a guide shaft 2032, a first rotating shaft 2033 and a second rotating shaft 2034. The guide shaft 2032 is circumferentially distributed between the two rotating disks 2031. The first rotating shaft 2033 and the second rotating shaft 2034 are both connected to the rotating disk 2031. The axes of the rotating disk 2031, the guide shaft 2032, the first rotating shaft 2033 and the second rotating shaft 2034 are all the same. The cam member 212 includes a cam 2121, a cam groove 2122 and a cam shaft 2123. The cam groove 2122 is arranged around the cam 2121, and the cam shaft 2123 is arranged at both ends of the cam 2121. The synchronization block 215 includes a slider 2151, a cylindrical guide block 2152 and a driving block 2153. The cylindrical guide block 2152 is arranged on the first end surface of the slider 2151, and the contact end with the cam groove 2122 in the cam member 212 is hemispherical. The driving block 2153 is arranged on the second end surface of the slider 2151. An arc groove is arranged on one side of the reel 205, and the driving block 2153 is slidably connected to the arc groove.

As shown in FIGS. 5 and 6 , the pulley deflection assembly 3 includes a support seat 31, a bearing block 32, a swinging member 33, a swinging pulley 34, a rack seat 35, a rack 36, a tension spring seat 37 and a tension spring 38. The bearing block 32 is arranged in the middle of the support seat 31, and the bearing block 32 is connected to the first end surface of the support seat 31. The rotating shaft 333 of the swinging member 33 is rotatably connected to the bearing block 32. The swinging block 331 of the swinging member 33 is slidably connected to the slide groove of the support seat 31. The swinging pulley 34 is arranged on the swinging member 33. At the middle position of the first end face of the moving member 33, the rack is arranged on the support seat through the rack seat, that is, the rack seat 35 is symmetrically arranged on the first end face of the support seat 31, the rack 36 is slidably connected with the rack seat 35, and the rack 36 is meshed with the fifth gear 332 of the swinging member 33 for transmission, the tension spring seat 37 is symmetrically arranged at both ends of the rack 36, the first end of the tension spring is connected with the rack through the tension spring seat, that is, the first end of the tension spring 38 is connected with the tension spring seat 37, and the second end of the tension spring 38 is connected with the rack seat 35. The swinging member 33 includes a swinging block 331, a fifth gear 332 and a rotating shaft 333, the swinging block 331 is slidably connected with the slide groove of the support seat 31, the fifth gear 332 is an incomplete gear, the fifth gear 332 is arranged at one side of the swinging block 331, and the fifth gear is meshed with the rack for transmission. The rotating shaft 333 is arranged at the middle of the second end surface of the swing block 331 , and is rotatably connected to the bearing block. The axis of the rotating shaft 333 coincides with the pulley tangent of the swing pulley 34 .

The number of pulley deflection assemblies, rope retracting assemblies and ropes is the same. The rope retracting assemblies 2 are arranged in six groups, and four groups of rope retracting assemblies are arranged at the four corners of the bottom plate, that is, four groups of rope retracting assemblies 2 are symmetrically arranged at the four corners of the first end surface of the bottom plate 41, and at least two groups of rope retracting assemblies 2 are symmetrically and obliquely arranged on the first end surface of the bottom plate 41. The pulley deflection assemblies 3 are arranged in six groups, and at least four groups of pulley deflection assemblies are arranged on the top plate, that is, at least four groups are symmetrically arranged on the first end surface of the top plate 43, and at least two groups of pulley deflection assemblies are symmetrically arranged on the first end surface of the bottom plate 41. Fixed pulleys are also arranged at the four corners of the bottom plate, that is, fixed pulleys 5 are arranged at the four corners of the first end surface of the bottom plate 41. The ropes 6 are arranged in six groups, wherein the first ends of at least four groups of ropes are wound around the drums 205 of the rope retracting and releasing assembly 2 at the four corner positions, and the second ends of the four groups of ropes are sequentially passed around the fixed pulley 5 and the swing pulley 34 of the pulley deflection assembly 3 at the top plate position and connected to the support plate 1092 of the pedal connecting frame 109. The first ends of at least two groups of ropes are wound around the drums 205 of the rope retracting and releasing assembly 2 arranged obliquely, and the second ends of the two groups of ropes are passed around the swing pulley 34 of the pulley deflection assembly 3 arranged on the bottom plate 41 and connected to the support plate 1092 of the pedal connecting frame 109.

As shown in Figure 7, rope retracting assembly A 21, rope retracting assembly B 22, rope retracting assembly C 23, and rope retracting assembly D 24 are four groups of rope retracting assemblies symmetrically arranged at the four corners of the first end surface of the bottom plate 41, and rope retracting assembly E 25 and rope retracting assembly F 26 are two groups of rope retracting assemblies symmetrically and obliquely arranged on the first end surface of the bottom plate 41.

As shown in FIG8 , Ti is the tension of six ropes, where i = 1 _, 2, 3, 4 _, 5 _{, 6} , Ti1 is the force component of the rope parallel to the rotation axis of the swing pulley, Ti2 is the _{force component perpendicular to the rotation axis of the swing pulley, F2} is the force of the swing member 33 on the rack 36, F3 is the force of the tension spring 38 on the rack 36, L is the center line of the support seat 31, θ is the angle between the rope and the center line L , and point O is the center of the rotation axis of the swing member 33; when the rope deflects, the swing pulley 34 is subjected to _{the force component Ti1} of the rope, the swing pulley 34 will deflect around point O , the swing member 33 generates a force F2 on the rack 36, the rack 36 is displaced _Δx , and the tension spring on the left is extended. According to Hooke's law: F = k Δx , it can be seen that the tension F3 of the tension spring increases; when the angle θ _between the rope 6 and the center line L increases, Ti1 _increases , F2 _increases , and F When _F2 is greater than F3 , the rack 36 moves to the left _{, and} the swing pulley ₃₄ deflects clockwise around the point O ; when the angle θ between the rope 6 and the center line L changes from large to small, Ti1 decreases, and F2 _{decreases .} Since F3 is greater than F2 , the rack 36 will move to the right. Since the fifth gear 332 of the swinging member 33 is engaged with the rack 36, the swinging member 33 rotates counterclockwise around the point O , and the swinging pulley 34 rotates counterclockwise. The swinging pulley 34 will always keep the same swinging direction as the rope 6.

As shown in FIGS. 9 and 10 , F _G is the weight of the human foot, F _G1 is the component of the weight of the human foot parallel to the pedal 111, F _G2 is the force exerted by the human foot on the pedal 111, F _d is the resistance of the damper 1035, F _d1 is the component of the resistance of the damper 1035 _in the vertical direction, and F _d2 is the component of the resistance of the damper 1035 in the horizontal direction; in the initial state, the tension Ti of the six ropes and the resistance F _d of the damper 1035 are balanced with the pressure F _G of the human foot on the pedal 111. When the ankle joint moves, _the tension Ti of the six ropes changes. When the movement axis of the ankle joint moves vertically upward, the resistance of the damper 1035 decreases, the moving seat 1034 moves upward, and the rotation axis of the rotating frame 104 moves upward in the vertical direction to coincide with the movement axis of the ankle joint. When the ankle joint performs dorsiflexion movement, the weight F _G of the human foot will generate a component F _G1 parallel to the pedal 111. , so that the spring 105 is compressed to compensate for the axis of motion of the ankle joint.

Another aspect of the present invention provides a control method for a motion axis adaptive ankle joint motion robot, as shown in FIG11 , which comprises the following steps:

S1. Place the foot on the pedal 111 and fix it to the pedal 111 with a bandage. Adjust the distance between the pedal 111 and the rotating frame 104 with the knob 112 so that the ankle joint axis coincides with the rotation axis of the rotating frame 104. Then fix the leg to the leg protector 45 with a strap.

S2. Establish a global coordinate system and a local coordinate system respectively. Take the center point of the bottom connection line of the two side pillars 101 as the origin O to establish the global coordinate system OX _b Y _b Z _b ; take the center of the semicircle of the pedal 111 as the coordinate origin Q to establish the local coordinate system QX _a Y _a Z _a ; take the intersection of the rotation axis of the rotating frame 104 and the axis of the bearing 107 as the coordinate origin P to establish the local coordinate system PXYZ ; Ai is the connection point of the rope Li and the moving platform, Bi _is the connection point of the rope Li and the swing pulley 34, where i = 1, 2, 3 _, 4 _, 5 _, 6.

S3. Based on the local coordinate system, the rotation angle α of the pedal 111 around the X axis, the rotation angle β around the Y axis, and the rotation angle γ around the Z axis, the posture of the pedal 111 is described by _the ZYX Euler angle , _then the rotation matrix of the local coordinate system QXaYaZa relative to the local coordinate system PXYZ _is ^P R _Q.

S4. According to the geometric characteristics and the vector parallelogram, the length of each rope l _i is expressed by the relationship between the rope connection point and the coordinate point. The specific expression is as follows:

, where i = 1, 2, 3, 4, 5, 6;

In the formula, l _i represents the length of each rope, represents the position vector from point A _i to point B _i ,/> represents the position vector from _point Bi to the origin P ,/> represents the position vector from the origin Q to the origin P ,/> Represents the position vector from _point Ai to the origin Q.

S5. Substituting each parameter point into the expression of rope length l _i , the specific relationship between each rope length and the pedal rotation angle can be obtained.

S6. Rotate the pedal 111 to the desired angle. According to the obtained specific relationship value, control the rotation angle of each motor through the controller to lengthen or shorten each rope to realize the rotation of the pedal 111 around the axis. The posture data of the pedal 111 can be monitored in real time through the posture sensor 113 and fed back to the controller to adjust the extension and retraction amount of each motor in real time.

In a preferred embodiment, as shown in Figures 12a to 13f, Figures 12a to 12c respectively show that the lengths of the first to sixth ropes extend or shorten as the rotation angle of the pedal 111 changes, and Figures 13a to 13f respectively show that the lengths of each rope change as the rotation angle changes when the pedal performs a compound movement of dorsiflexion/plantar flexion and inversion/eversion of the ankle joint around the X-axis and Y-axis, and no movement of adduction/abduction around the Z-axis occurs.

The following is a further description of a motion axis adaptive ankle joint motion robot and a control method thereof in conjunction with an embodiment of the present invention. The use process of the motion axis adaptive ankle joint motion robot of the present invention is as follows:

First, the user sits on the adjustable seat and places the user's feet on the pedal 111, fixing the user's feet to the pedal 111 with a bandage, adjusting the distance between the pedal 111 and the rotating frame 104 with the knob 112 so that the ankle joint axis coincides with the rotation axis of the rotating frame 104, and then fixing the user's legs to the leg protectors 45 with straps.

When the user performs dorsiflexion exercise, the motor 202 in the rope retracting assembly C 23 and the rope retracting assembly D 24 rotates to rotate the drum 205. While the drum 205 rotates, the gears and the cam cooperate to move the drum 205, and the rope 6 is evenly wound around the drum 205. The rope 6 wound around the drums of the rope retracting assembly C 23 and the rope retracting assembly D 24 shrinks. At the same time, the motor 202 in the rope retracting assembly A 21 and the rope retracting assembly B 22 rotates to rotate the drum 205, so that the rope 6 wound around the drums of the rope retracting assembly A 21 and the rope retracting assembly B The rope 6 on the drum 205 of 22 is stretched. At the same time, the damper 1035 in the double fork arm mechanism 103 will be stretched or shortened to passively adapt to the movement axis of the user's ankle joint. As the rope 6 contracts and stretches, the pedal 111 moves around the rotation axis of the rotating frame 104, causing the user's ankle joint to dorsiflex. Similarly, when the user performs plantar flexion, the motor 202 in the rope retracting assembly A 21, the rope retracting assembly B 22, the rope retracting assembly C 23, and the rope retracting assembly D 24 rotates in the opposite direction to the dorsiflexion movement.

When the user performs inversion movement, the motor 202 in the rope retracting assembly A 21 and the rope retracting assembly D 24 rotates to rotate the drum 205, so that the rope 6 wound on the drum 205 of the rope retracting assembly A 21 and the rope retracting assembly D 24 contracts, and the motor 202 in the rope retracting assembly B 22 and the rope retracting assembly C 23 rotates to rotate the drum 205, so that the rope 6 wound on the drum 205 of the rope retracting assembly B 22 and the rope retracting assembly C 23 extends. At the same time, the spring 105 will deform and passively adapt to the movement axis of the user's ankle joint. As the rope 6 contracts and extends, the pedal 111 moves around the spring seat 106, causing the user's ankle joint to perform inversion movement. Similarly, when the user performs eversion movement, the rotation direction of the motor 202 in the rope retracting assembly A 21, the rope retracting assembly B 22, the rope retracting assembly C 23, and the rope retracting assembly D 24 is opposite to the inversion movement.

When the user performs adduction movement, the motor 202 in the rope retracting assembly C 23 and the rope retracting assembly F 26 rotates to rotate the drum 205, so that the rope 6 wound on the drum 205 of the rope retracting assembly C 23 and the rope retracting assembly F 26 contracts. The motor 202 in the rope retracting assembly D 24 and the rope retracting assembly E 25 rotates to rotate the drum 205, so that the rope 6 wound on the drum 205 of the rope retracting assembly D 24 and the rope retracting assembly E 25 extends. At the same time, the spring 105 will deform and passively adapt to the movement axis of the user's ankle joint. As the rope 6 contracts and extends, and is limited by the spring 105, the user's ankle joint undergoes adduction movement. Similarly, when the user performs abduction movement, the rotation direction of the motor 202 in the rope retracting assembly C 23, the rope retracting assembly D 24, the rope retracting assembly E 25, and the rope retracting assembly F 26 is opposite to the adduction movement.

The motion axis adaptive ankle joint motion robot of the present invention realizes the fitting of the motion axis of the ankle joint with the motion axis of the robot through the double fork arm mechanism 103 and the spring 105, thereby avoiding injury during the movement of the ankle joint. The elongation and shortening of the rope 6 can be accurately controlled by the rotation angle of the motor 202 through the rope retracting and releasing assembly. The friction between the rope 6 and the pulley is reduced through the pulley deflection assembly 3, making it easier to change the direction of the rope 6. The dorsiflexion/plantar flexion, inversion/eversion, and internal rotation/external rotation of the ankle joint can be realized through the cooperation of the various components, thereby performing motion training on the ankle joint.

The embodiments described above are only descriptions of the preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims (10)

1. The motion axis self-adaptive ankle joint motion robot is characterized by comprising an axis compensation assembly, a rope retraction assembly, a pulley deflection assembly, a support assembly and a rope;

the axis compensation assembly comprises a support column, a fixed sleeve, a double-fork arm mechanism, a rotating frame, a spring, a pedal connecting frame, pedal sliding rails, pedals, a knob and a position sensor, wherein the support column is symmetrically arranged in the support assembly, a first end face of the support column is connected with a bottom plate of the support assembly, the fixed sleeve is connected with a second end face of the support column, two sides of the rotating frame are rotationally connected with the fixed sleeve through the double-fork arm mechanism, a first end of the spring is fixedly connected with the rotating frame, a second end of the spring is rotationally connected with a support arm of the pedal connecting frame, pedal sliding rails are symmetrically arranged on two sides of a support plate of the pedal connecting frame, the pedals are in sliding connection with the pedal sliding rails, the knob passes through the pedal sliding rails to be in threaded connection with the pedals, and the position sensor is connected with the pedals;

the rope winding and unwinding assembly is arranged on the bottom plate and comprises a motor, a drum shaft, a winding drum, a first gear, a gear frame, a second gear, a gear shaft, a third gear, a cam piece, a fourth gear, a guide rod and a synchronizing block, wherein the first rotating shaft of the drum shaft is connected with an output shaft of the motor through a coupler, the winding drum is in sliding connection with the guide shaft of the drum shaft, the second rotating shaft of the drum shaft is in rotating connection with the bottom plate through a bearing seat, the first gear is connected with the first rotating shaft of the drum shaft, the gear frame is arranged at one side position of the winding drum, the second gear is in rotating connection with the gear frame through the gear shaft, the second gear is in meshed transmission with the first gear, the third gear is in meshed transmission with the gear shaft, the cam shaft of the cam piece is in rotating connection with the gear frame, the fourth gear is in meshed transmission with the third gear, the guide rod is arranged at one side position of the cam piece, two ends of the guide rod are connected with the gear frame, the sliding block of the synchronizing block is in sliding connection with the guide rod, the cylindrical guide block of the synchronizing block is in sliding connection with the guide block of the cam piece, and the driving block of the synchronizing block is in sliding connection with the winding drum;

the pulley deflection assembly comprises a supporting seat, a bearing block, a swinging part, a swinging pulley, a rack, a tension spring seat and a tension spring, wherein the bearing block is connected with a first end face of the supporting seat, the swinging part is rotationally connected with the bearing block, the swinging part is in sliding connection with a sliding groove of the supporting seat, the swinging pulley is arranged in the middle of the swinging part, the rack is arranged on the supporting seat through the rack seat, the rack is in sliding connection with the rack seat, the rack is in meshed transmission with the swinging part, the first end of the tension spring is connected with the rack through the tension spring seat, and the second end of the tension spring is connected with the rack seat.

2. The motion axis adaptive ankle joint motion robot according to claim 1, wherein the support assembly comprises a base plate, a frame, a top plate, a leg support, a leg guard, and a universal wheel, the first end surface of the frame is connected to the first end surface of the base plate, the first end surface of the top plate is connected to the second end surface of the frame, the leg support is connected to the second end surface of the top plate, the leg guard is connected to the leg support, and the universal wheel is provided at four corners of the second end surface of the base plate.

3. The motion axis adaptive ankle joint motion robot according to claim 1, wherein the double-fork arm mechanism comprises an arm support, a first fork arm, a second fork arm, a movable seat and a damper, the arm support is connected with the fixed sleeve, first ends of the first fork arm and the second fork arm are both rotatably connected with the arm support, second ends of the first fork arm and the second fork arm are both rotatably connected with the movable seat, the first fork arm and the second fork arm are arranged in parallel, the first end of the damper is rotatably connected with the arm support, and the second end of the damper is rotatably connected with the movable seat.

4. The motion axis self-adaptive ankle joint motion robot according to claim 1, wherein the number of the pulley deflection assemblies, the rope winding and unwinding assemblies and the number of the ropes are the same, four groups of rope winding and unwinding assemblies are respectively arranged at four corners of the bottom plate, at least two groups of rope winding and unwinding assemblies are symmetrically and obliquely arranged on the bottom plate, at least four groups of pulley deflection assemblies are arranged on the top plate, and at least two groups of pulley deflection assemblies are symmetrically arranged on the bottom plate; the four corners position department of bottom plate still is provided with the fixed pulley, and the first end of four sets of ropes winds with the reel of the rope subassembly of receiving and releasing of four corners position department, and the swing pulley of the pulley deflection subassembly of fixed pulley and roof position is walked around in proper order to four sets of ropes's second end is connected with the backup pad of footboard link, and the first end of two sets of ropes winds with the reel of the rope subassembly of receiving and releasing that the slope set up, and the swing pulley of pulley deflection subassembly of setting at the bottom plate is walked around to two sets of ropes's second end is connected with the backup pad of footboard link.

5. The motion axis adaptive ankle motion robot according to claim 1, wherein the spool shaft comprises a rotating disc, a guide shaft, a first rotating shaft and a second rotating shaft, the guide shaft is circumferentially distributed between the two rotating discs, the first rotating shaft and the second rotating shaft are connected with the rotating discs, and axes of the rotating discs, the guide shaft, the first rotating shaft and the second rotating shaft are identical.

6. The motion axis adaptive ankle motion robot according to claim 1, wherein the cam member includes a cam, a cam groove, and a cam shaft, the cam groove being circumferentially provided on the cam, the cam shaft being provided at both ends of the cam.

7. The motion axis self-adaptive ankle joint motion robot according to claim 5, wherein the synchronizing block comprises a slider, a cylindrical guide block and a driving block, the cylindrical guide block is arranged on a first end face of the slider, a contact end of the cylindrical guide block with a cam groove in the cam piece is hemispherical, the driving block is arranged on a second end face of the slider, an arc-shaped groove is arranged at one side position of the winding drum, and the driving block is in sliding connection with the arc-shaped groove.

8. The motion axis self-adaptive ankle joint motion robot according to claim 1, wherein the swing member comprises a swing block, a fifth gear and a rotating shaft, the swing block is slidably connected with the sliding groove of the supporting seat, the fifth gear is arranged at one side position of the swing block, the fifth gear is in meshed transmission with the rack, the rotating shaft is arranged at the middle position of the second end face of the swing block, the rotating shaft is rotatably connected with the bearing block, and the axis of the rotating shaft coincides with a pulley tangent line of the swing pulley.

9. The motion axis self-adaptive ankle joint motion robot according to claim 1, wherein the pedal connecting frame comprises a support arm and a support plate, the support arm and the support plate are vertically arranged, through holes are arranged at the tail ends of the support arm and are connected with bearings of the axis compensation assembly, slotted holes are arranged at four corners of the support plate, and the ropes are connected with the support plate through the slotted holes; the end positions of the two sides of the rotating frame are symmetrically provided with hollow cylinders, the movable seat is provided with a solid cylinder, and the inner side of the hollow cylinder is rotationally and slidingly connected with the solid cylinder.

10. A method of controlling an axis of motion adaptive ankle joint movement robot according to any one of claims 1 to 9, comprising the steps of:

s1, placing feet on a pedal, fixing the foot with the pedal through a bandage, adjusting the distance between the pedal and a rotating frame through a knob to enable the axis of an ankle joint to coincide with the rotating axis of the rotating frame, and then fixing legs with leg protectors through the bandage;

s2, respectively establishing a global coordinate system and a local coordinate system, and taking the central point of the connecting line of the bottoms of the two side support posts as the originOEstablishing global coordinatesIs tied up withOX _b Y _b Z _b The method comprises the steps of carrying out a first treatment on the surface of the With the center of the pedal semicircle as the origin of coordinatesQEstablishing a local coordinate systemQX _a Y _a Z _a The method comprises the steps of carrying out a first treatment on the surface of the Taking the intersection point of the rotation axis of the rotating frame and the axis of the bearing as the origin of coordinatesPEstablishing a local coordinate systemPXYZ；A _i Is a ropeL _i The connection point with the movable platform is provided with a connecting point,B _i is a ropeL _i Connection point with swinging pulley, whereini=1,2,3,4,5,6；

S3, based on a local coordinate system, winding the pedalXRotation angle of shaftαWindingYRotation angle of shaftβWindingZRotation angle of shaftγ，By usingZYXEuler angle describes the pose of the pedal, then the local coordinate systemQX _a Y _a Z _a Relative to a local coordinate systemPXYZIs the rotation matrix of (a) ^P R _Q ；

S4, according to the geometric characteristics and the vector parallelogram, the lengths of the ropes are respectively equal tol _i Expressed by the relation between the rope connection point and the coordinate point, the specific expression is as follows:

whereini=1,2,3,4,5,6；

In the method, in the process of the invention,l _i indicating the length of each rope and,representation ofA _i Point to pointB _i Position vector of point, ">Representation ofB _i Point to originPPosition vector of>Representing the originQTo the origin pointPPosition vector of>Representation ofA _i Point to originQIs a position vector of (2);

s5, substituting each parameter point into the length of the ropel _i In the expression, a specific relation value between the length of each rope and the rotation angle of the pedal can be obtained;

and S6, rotating the pedal by a required angle, controlling the rotating angle of each motor through a controller according to the obtained specific relation value, and realizing the extension or shortening of each rope so as to realize the rotation of the pedal around the axis, wherein the gesture data of the pedal can be monitored in real time through a gesture sensor and fed back to the controller so as to adjust the expansion and contraction amount of each motor in real time.