Lower limb stepping training system

Abstract

The invention provides a lower limb stepping training system, which is used for performing rehabilitation training on lower limbs when a hemiplegic patient walks, and comprises a stepping assembly, a six-dimensional force sensor and a controller, the stepping assembly comprises a transverse moving mechanism, a lifting mechanism and a pedal mechanism, and the controller comprises an active training mode and a passive training mode. In the active training mode, the following steps are executed: reading an external force applied to the pedal mechanism from the six-dimensional force sensor; the external force is decomposed into horizontal force in the horizontal direction and vertical force in the vertical direction; on the basis of the horizontal force data and the motor position # imgabs0 # at the current moment, the motor position # imgabs1 # at the next moment is obtained through calculation, and motor position data at the next moment are sent to the transverse moving mechanism; and the motor position # imgabs3 # at the next moment is obtained through calculation based on the vertical force data and the motor position # imgabs2 # at the current moment, and the motor position data at the next moment are sent to the lifting mechanism.

Description

Technical Field

[0001] The invention relates to the technical field of motion correction, in particular to a lower limb stepping training system. Background Art

[0002] Walking disorders are usually caused by nervous system damage, musculoskeletal diseases or surgical sequelae. Lower limb training is an important part of restoring the user's walking ability. Traditional training methods rely on manual operation, which is inefficient and difficult to meet the hospital's requirements for efficient, practical and precise training. However, existing lower limb training equipment has some limitations. Most of them focus on passive training of a single joint or cannot effectively simulate real joint movements, which limits the maximization of training effects. Lower limb walking training has significant benefits for restoring the user's walking function, improving gait and preventing ankle injuries. Therefore, in order to better meet the needs of users, a system is needed that can simulate lower limb walking movements in real time to drive patients to perform lower limb stepping training. Summary of the invention

[0003] In order to solve the defects in the prior art, the present invention proposes a lower limb stepping training system.

[0004] The present invention discloses a lower limb walking training system, which is used for rehabilitation training of lower limbs of hemiplegic patients when they walk, and comprises a walking component, a six-dimensional force sensor and a controller.

[0005] The stepping assembly comprises: a frame, and a left stepping assembly and a right stepping assembly arranged side by side on the frame along a first horizontal direction, the left stepping assembly and the right stepping assembly both comprising a transverse movement mechanism, a lifting mechanism and a pedal mechanism, the pedal mechanism being arranged at a driving end of the lifting mechanism for carrying a user's foot, the lifting mechanism being arranged at a driving end of the transverse movement mechanism for driving the pedal mechanism to move up and down, the transverse movement mechanism being arranged on the frame for driving the pedal mechanism to move transversely along a second horizontal direction, the second horizontal direction being perpendicular to the first horizontal direction,

[0006] The six-dimensional force sensor is arranged at the bottom of the pedal mechanism and is used to sense the external force applied to the pedal mechanism.

[0007] The controller includes an active training mode and a passive training mode, and performs the following steps in the active training mode:

[0008] reading the external force applied to the pedal mechanism from the six-dimensional force sensor;

[0009] Decomposing the external force into a horizontal force in a horizontal direction and a vertical force in a vertical direction;

[0010] Based on the horizontal force data and the motor position at the current moment Calculate the motor position at the next moment The motor position data at the next moment is sent to the transverse movement mechanism. At the same time, based on the vertical force data and the motor position at the current moment, Calculate the motor position at the next moment and sending the motor position data at the next moment to the lifting mechanism, and

[0011] The transverse movement mechanism and the lifting mechanism respectively drive the pedal mechanism based on the received motor position data at the next moment.

[0012] Preferably, the motor position at the next moment is calculated by an admittance control algorithm.

[0013] Preferably, the admittance algorithm is:

[0014]

[0015] The points can be obtained:

[0016]

[0017] in:

[0018] F e The horizontal force or vertical force decomposed from the external force applied to the pedal mechanism,

[0019] That is, the actual position x and the expected position x of the pedal mechanism described in the basic coordinate system at time t d The actual position x is obtained by the controller directly reading the motor, and the expected position x d It is obtained from the normal gait curve of normal people. for The first derivative of for The second derivative of , K is the diagonal matrix of stiffness coefficients, B is the diagonal matrix of damping coefficients, M is the diagonal matrix of inertia coefficients, K, B, and M are obtained from experimental data.

[0020] Preferably, the controller calculates the motor position at the next moment The chaotic interference value x is also included n The motor position at the next moment is:

[0021] Preferably, the chaotic interference value x n It is obtained from the following chaos formula:

[0022] h n =u*hn-1 *(1-h n-1 ) (4)

[0023] x n =A*h n (5)

[0024] Among them, h n is the chaos factor at the current moment, h n-1 is the chaos factor at the previous moment, the initial h0 is an arbitrary value between (0,1) set artificially, u is the chaos coefficient, set by the trainer, and A is the maximum interference value set artificially.

[0025] Preferably, the chaos coefficient u is any value between (3.5699, 4].

[0026] Preferably, the transverse movement mechanism includes a first ball screw rotatably mounted on the frame, a first screw nut transmission-connected to the first ball screw, and a first motor driving the first ball screw to rotate, the first ball screw extends along a second horizontal direction, and the lifting mechanism is connected to the first screw nut.

[0027] Preferably, it also includes a mounting frame arranged at the driving end of the transverse movement mechanism, the lifting mechanism includes a driving assembly arranged on the mounting frame, a lifting scissors and a mounting plate arranged on the top of the lifting scissors, the foot mechanism is installed on the mounting plate, and the driving assembly drives the foot mechanism to rise and fall through the lifting scissors.

[0028] Preferably, the driving assembly includes a second ball screw rotatably mounted on the mounting frame, a second screw nut transmission-connected to the second ball screw, and a second motor driving the second screw nut to linearly move through the second ball screw.

[0029] Preferably, in the passive training mode, the controller calculates the motor position at the next moment based on a normal gait curve set in advance. And the motor position data at the next moment is sent to the transverse movement mechanism and the lifting mechanism respectively.

[0030] The present invention has the following beneficial effects:

[0031] 1. The lower limb walking training system of the present invention, through the setting of the lateral movement mechanism, the lifting mechanism and the pedal mechanism, is controlled by a controller to control the lateral movement mechanism and the lifting mechanism to simulate the motion trajectory and force changes of a normal gait, so as to help users with lower limb impairments to restore their gait and walking ability.

[0032] 2. The lower limb stepping training system of the present invention can not only improve the user's muscle strength, balance ability and gait stability, but also provide real-time feedback and guidance, record training data, and provide a scientific basis for training treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a structural schematic diagram of a lower limb stepping training system according to a preferred embodiment of the present invention.

[0034] Figure 2 It is a stereoscopic view of a stepping assembly according to a preferred embodiment of the present invention.

[0035] Figure 3 It is a three-dimensional diagram of a lifting mechanism and a pedal mechanism according to a preferred embodiment of the present invention.

[0036] Figure 4 It is a front view of a lifting mechanism and a pedal mechanism according to a preferred embodiment of the present invention.

[0037] Figure 5 This is a partial structural diagram of a lifting mechanism in one of the embodiments of the present application.

[0038] Figure 6 It is a workflow diagram of a lower limb stepping training system according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0039] The following will illustrate the implementation methods of the present invention in conjunction with the drawings in the specification. It should be noted that the implementation methods involved in this specification are not exhaustive and do not represent the only implementation methods of the present invention. The following corresponding embodiments are only for the purpose of clearly illustrating the invention content of the patent of the present invention, and are not intended to limit its implementation methods. For ordinary technicians in this field, different forms of changes and modifications can be made on the basis of the description of this embodiment. All obvious changes or modifications that belong to the technical concept and invention content of the present invention are also within the scope of protection of the present invention.

[0040] Figure 1 It is a structural schematic diagram of a lower limb stepping training system according to a preferred embodiment of the present invention. Figure 2 It is a stereoscopic view of a stepping assembly according to a preferred embodiment of the present invention. Figure 3 It is a three-dimensional diagram of a lifting mechanism and a pedal mechanism according to a preferred embodiment of the present invention. Figure 4 FIG. 1 is a three-dimensional diagram of a lifting mechanism of a preferred embodiment of the present invention. Figure 1-4 As shown, a lower limb walking training system according to a preferred embodiment of the present invention is used for rehabilitation training of the lower limbs of hemiplegic patients when walking, and includes a walking component 1, a six-dimensional force sensor 2 and a controller 3.

[0041] A stepping assembly 1 of a preferred embodiment of the present invention comprises: a frame 11 and a left stepping assembly 12 and a right stepping assembly 12' arranged side by side on the frame 11 along a first horizontal direction. The left stepping assembly 12 is used to drive the user's left lower limb to perform stepping training, and the right stepping assembly 12' is used to drive the user's right lower limb to perform stepping training. Since the left stepping assembly 12 and the right stepping assembly 12' are bilaterally symmetrical and have exactly the same structure, the left stepping assembly 12 is taken as an example for detailed description below. The left stepping assembly 12 comprises a transverse movement mechanism 13, a lifting mechanism 14 and a pedal mechanism 15. The pedal mechanism 15 is arranged at the driving end of the lifting mechanism 14 and is used to support the sole of the user's foot. The lifting mechanism 14 is arranged at the driving end of the transverse movement mechanism 13 and is used to drive the pedal mechanism 15 to move up and down. The transverse movement mechanism 13 is arranged on the frame 11 and is used to drive the pedal mechanism 15 to move horizontally along a second horizontal direction, and the second horizontal direction is perpendicular to the first horizontal direction.

[0042] The six-dimensional force sensor 2 is disposed at the bottom of the pedal mechanism 15 and is used to sense the external force applied to the pedal mechanism 15.

[0043] The controller 3 includes an active training mode and a passive training mode. The active training mode means that when the user has a certain athletic ability but the movements are not standardized, the stepping component 1 allows the user to take the initiative and applies a corrective force to the foot so that the lower limb movement is corrected to the standardized movement. The passive training mode means that when the user is not yet able to perform active training, the motor of the stepping component 1 fits the established trajectory to drive the user's lower limbs to perform exercise training, and the user is in a passive state at this time.

[0044] like Figure 5 As shown, the controller 3 performs the following steps in the active training mode.

[0045] Step S1: reading the external force applied to the pedal mechanism 15 from the six-dimensional force sensor 2;

[0046] Step S2: decomposing the external force into a horizontal force in the horizontal direction and a vertical force in the vertical direction;

[0047] Step S3: Based on the horizontal force data and the motor position at the current moment Calculate the motor position at the next moment The motor position data of the next moment is sent to the transverse movement mechanism 13. At the same time, based on the vertical force data and the motor position of the current moment, Calculate the motor position at the next moment And the motor position data at the next moment is sent to the lifting mechanism 14.

[0048] Then, after receiving the instruction from the controller 3, the lateral movement mechanism 13 and the lifting mechanism 14 execute step S5: based on the received motor position data at the next moment, the pedal mechanism 15 is driven to perform ascending and descending and forward and backward translational movements to simulate the walking action. Thus, when the user is training, the user's lower limb walking action can be corrected in real time, making the walking training more effective and closer to the real and natural normal state.

[0049] In addition, in the passive training mode, the controller 3 calculates the motor position at the next moment based on the normal gait curve set in advance. The motor position data at the next moment is sent to the transverse mechanism 13 and the lifting mechanism 14. The transverse mechanism 13 and the lifting mechanism 14 drive the pedal mechanism 15 based on the received motor position data at the next moment, thereby driving the user to perform lower limb stepping rehabilitation training.

[0050] In a preferred embodiment, the motor position at the next moment calculated in step S3 is obtained by an admittance control algorithm. Specifically, the admittance algorithm is:

[0051]

[0052] The points can be obtained:

[0053]

[0054] in:

[0055] F e is the horizontal force or vertical force decomposed from the external force applied to the pedal mechanism 15,

[0056] That is, the actual position x and the expected position x of the pedal mechanism described in the basic coordinate system at time t d The actual posture x is obtained by the controller 3 directly reading the motor, and the expected posture x d It is obtained from the normal gait curve of normal people. for The first derivative of for The second-order derivative of K is the diagonal matrix of stiffness coefficient, B is the diagonal matrix of damping coefficient, and M is the diagonal matrix of inertia coefficient. K, B, and M are obtained from experimental data. Generally speaking, the larger the M, the greater the inertia. If it is too small, the admittance control amount will exceed the allowable range. The larger the K, the greater the stiffness. If it is too small, it will cause a large tracking error. Then, according to the desired damping ε, the value of B is further obtained. Increasing damping helps to reduce the rebound phenomenon.

[0057] In the above preferred embodiment, the motor can be controlled compliantly by the admittance control algorithm. This control method does not require a dynamic model of the robot and is particularly suitable for a servo control system that requires good position control effects.

[0058] In a more preferred embodiment, step S3 may be followed by step S4 of superimposing the chaotic interference value: the controller 3 calculates the motor position at the next moment Post-superposition chaotic interference value x n , that is, the motor position at the next moment is:

[0059] The chaotic interference value x n It is obtained from the following chaos formula:

[0060] h n =u*h n-1 *(1-h n-1 ) (4)

[0061] x n =A*h n (5)

[0062] Among them, h n is the chaos factor at the current moment, h n-1 is the chaos factor of the previous moment, the initial h0 is an arbitrary value between (0,1) set manually, u is the chaos coefficient, set by the trainer, and the chaos coefficient u is an arbitrary value between (3.5699,4]. A is the maximum interference value set manually.

[0063] As described above, by superimposing the chaotic interference value on the motor position data at the next moment, the left step component 12 is based on the superimposed motor position data at the next moment. When the pedal mechanism 15 is driven to move, the trainee can be closer to the real walking environment, and the trainee's walking ability can be further enhanced. Here, no matter in the active training mode or the passive training mode, the chaotic interference value can be superimposed.

[0064] Combine the following Figure 2-4 The specific structures of the transverse movement mechanism and the lifting mechanism of the preferred embodiment of the present invention are further explained.

[0065] In the present application, the lifting mechanism 14 and the lateral movement mechanism 13 can jointly drive the pedal mechanism 15 to move up and down and forward and backward to simulate the human body's stepping action. When the user's foot steps on the pedal mechanism 15, the lifting mechanism 13 and the lateral movement mechanism 14 cooperate with each other to drive the user to step, so as to perform lower limb movement training.

[0066] In some preferred embodiments, the traverse mechanism 13 includes a first ball screw 131, a first screw nut 132, and a first motor 133. The first ball screw 131 extends along the second horizontal direction, and first bearing seats 134 are provided at both ends of the first ball screw 131. The first bearing seats 134 are fixedly mounted on the frame 11, and both ends of the first ball screw 131 are inserted into the bearings of the first bearing seats 134 at the corresponding ends, and are interference fit with the bearings to be rotatably mounted on the frame 11. The first screw nut 132 is sleeved on the first ball screw 131 and is threadedly driven with the first ball screw 131, and the lifting mechanism 15 is arranged on the first screw nut 132. The first motor 133 is disposed at one end of the first ball screw 131 and fixedly mounted on the frame 11. The motor shaft of the first motor 133 is fixedly connected to one end of the first ball screw 131, and is used to drive the first ball screw 131 to rotate, so that the first screw nut 132 drives the lifting mechanism 14 to move linearly along the first ball screw 131, and then the pedal mechanism 15 moves along the second horizontal direction.

[0067] See also Figure 2-4 As shown, in some embodiments, the lower limb stepping training system of the present invention also includes a first guide rail 8 and a mounting frame 9, and the first guide rail 8 extends along the second horizontal direction, and two are arranged in parallel. The two first guide rails 8 are located on the same side of the first ball screw 131. The mounting frame 9 is arranged between the two first guide rails 8, and the two ends of the mounting frame 9 are slidably mounted on the two first guide rails 8 through sliders, so that the subsequent mounting frame 9 can move stably along the second horizontal direction. The first screw nut 132 is fixedly connected to the mounting frame 9 through a connecting seat to drive the mounting frame 9 to move horizontally along the second horizontal direction. The lifting mechanism 14 is arranged on the mounting frame 9, so that the lifting mechanism 14 and the pedal mechanism 6 follow the mounting frame 9 to move horizontally along the second horizontal direction synchronously.

[0068] In some embodiments, the lifting mechanism 14 includes a driving assembly 141 arranged on the mounting frame 9, a lifting scissors fork 142, and a mounting plate 143 arranged on the top of the lifting scissors fork 142, the pedal mechanism 15 is installed on the mounting plate 143, and the driving assembly 141 drives the pedal mechanism 15 to rise and fall through the lifting scissors fork 142.

[0069] Specifically, the driving assembly 141 includes a second ball screw 1411, a second screw nut 1412 and a second motor 1413. The second ball screw 1411 extends along the second horizontal direction. A second bearing seat (not shown) is provided at both ends of the second ball screw 1411, and the second bearing seat is fixedly mounted on the mounting frame 9. Both ends of the second ball screw 1411 are inserted into the bearings of the second bearing seats at the corresponding ends, and are interference fit with the bearings to be rotatably mounted on the mounting frame 9. The second screw nut 1412 is sleeved on the second ball screw 1411 and is threadedly driven with the second ball screw 1411. The second motor 1413 is provided at one end of the second ball screw 1411 and is fixedly mounted on the mounting frame 9. The motor shaft of the second motor 1413 is fixedly connected to one end of the second ball screw 1411 to drive the second ball screw 1411 to rotate, so that the second screw nut 1412 moves linearly along the second ball screw 1411.

[0070] The lifting scissors 142 includes a first connecting rod 1421 and a second connecting rod 1422 that are intersecting and hinged, the first connecting rod 1421 is hinged with a first hinge seat 1423 and a second hinge seat 1424 at the upper and lower ends, respectively, and the second connecting rod 1422 is hinged with a third hinge seat 1425 and a fourth hinge seat 1426 at the upper and lower ends. A second guide rail 144 extending along the second horizontal direction is provided at the bottom of the mounting plate 143, the first hinge seat 1423 is provided at the bottom of the mounting plate 143, the second hinge seat 1424 is provided on the second screw nut 1412, the third hinge seat 1425 is slidably installed on the second guide rail 144 through a slider, and the fourth hinge seat 1426 is provided on the mounting frame 9.

[0071] Thus, the second motor 1413 can drive the second hinge seat 1424 to move along the second horizontal direction through the second screw nut 1412 to drive the mounting plate 143 to rise and fall, so that the mounting plate 143 drives the pedal mechanism 15 to rise and fall synchronously.

[0072] In some embodiments, a third guide rail 145 parallel to the second ball screw 1411 is also provided on the mounting frame 9. Two third guide rails 145 are provided and are respectively located on both sides of the second ball screw 1411. The second hinge seat 1424 is also slidably installed on the two third guide rails 145 through a slider. The third guide rail 145 can guide the movement of the second hinge seat 1424, thereby improving the stability of the lifting drive of the lifting scissors 142.

[0073] In some embodiments, two second connecting rods 1422 are arranged in parallel, the two second connecting rods 1422 are fixedly connected, and the first connecting rod 1421 is arranged between the two second connecting rods 1422. The mounting plate 143 is supported by three connecting rods, further increasing the stability of the lifting and lowering of the mounting plate 143.

[0074] In a preferred embodiment, the controller 3 also collects pressure / torque data applied to the pedal mechanism 15 based on the six-dimensional force sensor 2 on the sole of the foot, which is used to extract gait characteristics in order to analyze the user's walking condition, thereby providing real-time feedback and guidance, recording the user's training data, etc.

[0075] As described above, the lower limb stepping training system of the present invention guides the user to perform gait training and exercise by simulating the motion trajectory and force changes of a normal gait. Stepping training includes at least two or more modes: passive training and active training, diversified motion patterns, and different forms of gait training to meet the personalized needs of users. In addition, the device drives the movement of the stepping component through a motor and a reducer according to preset motion patterns and parameters, so that the user's lower limbs simulate the motion trajectory of a normal gait. The user performs gait training under the real-time guidance and correction of the device, and through repeated movements and exercises, it can effectively promote the training and functional recovery of the lower limbs.

[0076] Obviously, those skilled in the art should realize that the above embodiments are only used to illustrate the present invention, and are not used to limit the present invention. As long as they are within the spirit of the present invention, any changes or modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. A lower limb walking training system, used for rehabilitation training of lower limbs of hemiplegic patients while walking, characterized in that: Including stepping components, six-dimensional force sensors and controllers, The stepping assembly comprises: a frame, and a left stepping assembly and a right stepping assembly arranged side by side on the frame along a first horizontal direction, the left stepping assembly and the right stepping assembly both comprising a transverse movement mechanism, a lifting mechanism and a pedal mechanism, the pedal mechanism being arranged at a driving end of the lifting mechanism for carrying a user's foot, the lifting mechanism being arranged at a driving end of the transverse movement mechanism for driving the pedal mechanism to move up and down, the transverse movement mechanism being arranged on the frame for driving the pedal mechanism to move transversely along a second horizontal direction, the second horizontal direction being perpendicular to the first horizontal direction, The six-dimensional force sensor is arranged at the bottom of the pedal mechanism and is used to sense the external force applied to the pedal mechanism. The controller includes an active training mode and a passive training mode, and performs the following steps in the active training mode: reading the external force applied to the pedal mechanism from the six-dimensional force sensor; Decomposing the external force into a horizontal force in a horizontal direction and a vertical force in a vertical direction; Based on the horizontal force data and the motor position at the current moment Calculate the motor position at the next moment The motor position data at the next moment is sent to the transverse movement mechanism. At the same time, based on the vertical force data and the motor position at the current moment, Calculate the motor position at the next moment and sending the motor position data at the next moment to the lifting mechanism, and The transverse movement mechanism and the lifting mechanism respectively drive the pedal mechanism based on the received motor position data at the next moment.

2. The lower limb stepping training system according to claim 1, characterized in that: The motor position at the next moment is calculated by an admittance control algorithm.

3. The lower limb stepping training system according to claim 2, characterized in that: The admittance algorithm is: The points can be obtained: in: F e The horizontal force or vertical force decomposed from the external force applied to the pedal mechanism, That is, the actual position x and the expected position x of the pedal mechanism described in the basic coordinate system at time t d The actual position x is obtained by the controller directly reading the motor, and the expected position x d It is obtained from the normal gait curve of normal people. for The first derivative of for The second derivative of , K is the diagonal matrix of stiffness coefficients, B is the diagonal matrix of damping coefficients, M is the diagonal matrix of inertia coefficients, K, B, and M are obtained from experimental data.

4. The lower limb stepping training system according to claim 1, characterized in that: The controller calculates the motor position at the next moment The chaotic interference value x is also included n The motor position at the next moment is:

5. The lower limb stepping training system according to claim 4, characterized in that: The chaotic interference value x n It is obtained from the following chaos formula: h n =u*h n-1 *(1-h n-1 ) (4) x n =A*h n (5) Among them, h n is the chaos factor at the current moment, h n-1 is the chaos factor at the previous moment, the initial h0 is an arbitrary value between (0,1) set artificially, u is the chaos coefficient, set by the trainer, and A is the maximum interference value set artificially.

6. The lower limb stepping training system according to claim 5, characterized in that: The chaos coefficient u is any value between (3.5699, 4].

7. The lower limb stepping training system according to claim 1, characterized in that: The transverse movement mechanism includes a first ball screw rotatably mounted on the frame, a first screw nut transmission-connected to the first ball screw, and a first motor driving the first ball screw to rotate. The first ball screw extends along a second horizontal direction, and the lifting mechanism is connected to the first screw nut.

8. The lower limb stepping training system according to claim 7, characterized in that: It also includes a mounting frame arranged at the driving end of the transverse movement mechanism, the lifting mechanism includes a driving component arranged on the mounting frame, a lifting scissors and a mounting plate arranged on the top of the lifting scissors, the foot mechanism is installed on the mounting plate, and the driving component drives the foot mechanism to rise and fall through the lifting scissors.

9. The lower limb stepping training system according to claim 8, characterized in that: The driving assembly includes a second ball screw rotatably mounted on the mounting frame, a second screw nut transmission-connected to the second ball screw, and a second motor driving the second screw nut to move linearly through the second ball screw.

10. The lower limb stepping training system according to claim 1, characterized in that: In the passive training mode, the controller calculates the motor position at the next moment based on the normal gait curve set in advance. And the motor position data at the next moment is sent to the transverse movement mechanism and the lifting mechanism respectively.

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