Ankle motion correction system

Abstract

The application provides an ankle action correction system for the rehabilitation training of ankle joints of a hemiplegic patient during walking, comprising an ankle action simulator and a controller, wherein the ankle action simulator comprises a base, a sole plate, a left driving mechanism and a right driving mechanism; in an active training mode, current data of a left motor of the left driving mechanism and current data of a right motor of the right driving mechanism are read; external force F e applied to the left motor and the right motor is respectively calculated according to the current data of the motors; the motor position at the next moment is calculated based on the data of the external force and the motor position at the current moment, and the motor position data at the next moment are respectively sent to the left driving mechanism and the right driving mechanism; the left driving mechanism and the right driving mechanism drive the sole plate to swing forward and backward relative to the base or turn to the left or the right based on the received motor position data at the next moment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motion correction, and particularly relates to an ankle action correction system. BACKGROUND

[0002] Walking disorders are usually caused by nervous system injury, musculoskeletal diseases or postoperative sequelae. Lower limb training is an important link for restoring the walking ability of a user. Traditional training methods rely on manual operation, which is low in efficiency and difficult to meet the requirements of hospitals for efficient, practical and accurate training. The existing lower limb training equipment has some limitations, most of which are focused on passive training of a single joint or cannot effectively simulate real joint movement, especially the joint movement of the ankle joint, which limits the maximization of training effect. Ankle joint training plays a crucial role in walking training, which has significant benefits for restoring the walking function of a user, improving gait and preventing ankle joint injury. Therefore, in order to better meet the needs of users, an ankle action correction system capable of simulating ankle action to drive patients for ankle joint rehabilitation correction is needed. SUMMARY

[0003] The present application relates to the technical field of motion correction, and particularly relates to an ankle action correction system.

[0004] The ankle action correction system of the present application is used for rehabilitation training of the ankle joint of a hemiplegic patient during walking, and comprises an ankle action simulator and a controller,

[0005] The ankle action simulator comprises a base, a foot plate, a left drive mechanism and a right drive mechanism. The foot plate is connected to the base in a universal manner and is used for supporting the instep of a patient. The left drive mechanism is hingedly connected to the left edge of the bottom of the foot plate, and the right drive mechanism is hingedly connected to the right edge of the bottom of the foot plate. The left drive mechanism and the right drive mechanism are used for driving the foot plate to move relative to the base to drive the instep of the patient to perform ankle joint rehabilitation training. The left drive mechanism comprises a left motor and a left linkage assembly driven by the left motor. The right drive mechanism comprises a right motor and a right linkage driven by the right motor.

[0006] The controller is connected to the ankle action simulator and comprises an active training mode and a passive training mode.

[0007] In the active training mode, the controller performs the following steps:

[0008] Reading current data of the left motor of the left drive mechanism and current data of the right motor of the right drive mechanism;

[0009] According to the current data of the motors, the external force F applied to the left motor and the right motor is calculated respectively.e ;

[0010] based on the data of the external force and the motor position at the current time to obtain the motor position at the next time and send the motor position data at the next time to the left driving mechanism and the right driving mechanism respectively,

[0011] In the passive training mode, the controller obtains the motor position at the next time based on the ankle position curve of a normal person set in advance and sends the motor position data at the next time to the left driving mechanism and the right driving mechanism respectively,

[0012] The left driving mechanism and the right driving mechanism drive the foot plate to swing forward and backward relative to the base or turn to the left or right based on the received motor position data at the next time.

[0013] Preferably, in the active training mode, the motor position at the next time is obtained by a mobility control algorithm.

[0014] Preferably, the mobility algorithm is:

[0015]

[0016] After integration, we get:

[0017]

[0018] Where:

[0019] F e is the external force applied to the left motor of the left driving mechanism or the right motor of the right driving mechanism,

[0020] is the difference between the actual pose x of the foot plate described in the base coordinate system at time t and the expected pose x d , the actual pose x is obtained by the controller reading the motor directly, and the expected pose x d is obtained from the ankle position curve of a normal person, is the first derivative of , and is the second derivative of , K is a stiffness coefficient diagonal matrix, B is a damping coefficient diagonal matrix, and M is an inertia coefficient diagonal matrix. K, B, and M are obtained from experimental data.

[0021] Preferably, the controller obtains the motor position at the next time and further includes a superimposed chaotic interference value x nThe next time motor position is:

[0022] Preferably, the chaotic interference value x n is obtained by the following chaotic formula:

[0023] h n = u * h n-1 *(1-h n-1 ) (4)

[0024] x n =A*h n (5)

[0025] wherein h n is the current time chaotic factor, h n-1 is the previous time chaotic factor, the initial h0 is an arbitrary value between (0, 1) set by human, u is the chaotic coefficient set by the training personnel, and A is the maximum interference value set by human.

[0026] Preferably, the chaotic coefficient u is an arbitrary value between (3.5699, 4].

[0027] Preferably, the next time motor position data includes the motor position data of the left driving mechanism and the motor position data of the right driving mechanism.

[0028] Preferably, a six-dimensional force sensor is further included, which is arranged at the bottom of the base of the ankle action simulator.

[0029] Preferably, the six-dimensional force sensor collects the force curve applied to the ankle action simulator during walking and sends it to the controller for extracting gait features.

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

[0031] The ankle action correction system of the present application can simulate the flexion and extension movement of the ankle joint, adjust the speed and strength of the movement, provide real-time feedback and guidance, record the training data of the user, etc. By precisely controlling and simulating the movement of the ankle, the ankle simulator can help the user improve the muscle strength, balance ability and gait stability, promote the training and functional recovery of the lower limbs. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a structural schematic diagram of the ankle action correction system of a preferred embodiment of the present application.

[0033] Figure 2 is a perspective view of the ankle action simulator of a preferred embodiment of the present application.

[0034] Figure 3 is another perspective view of the ankle motion simulator of a preferred embodiment of the present application.

[0035] Figure 4 is a structural schematic view of the ankle motion simulator of a preferred embodiment of the present application.

[0036] Figure 5 is a flow chart of the working process of the ankle motion simulation system of a preferred embodiment of the present application. DETAILED DESCRIPTION

[0037] The embodiments of the present application will be described below with reference to the accompanying drawings. It should be noted that the embodiments described in the present specification are not exhaustive, and do not represent the only embodiments of the present application. The following embodiments are only for the purpose of clearly illustrating the content of the present application, and are not intended to limit the embodiments of the present application. For those skilled in the art, based on the description of the embodiments, different forms of changes and modifications can also be made, and any changes or modifications that fall within the technical concept and content of the present application and are obvious are within the protection scope of the present application.

[0038] Figure 1 is a structural schematic view of the ankle motion simulator of a preferred embodiment of the present application. Figure 2 is a perspective view of the ankle motion simulator of a preferred embodiment of the present application. Figure 3 is another perspective view of the ankle motion simulator of a preferred embodiment of the present application. Figure 4 is a structural schematic view of the ankle motion simulator of a preferred embodiment of the present application. As shown in Figures 1-4 the ankle motion simulator of a preferred embodiment of the present application is used for rehabilitation training of the ankle joint of a hemiplegic patient during walking, and includes an ankle motion simulator 1, a six-dimensional force sensor 2, and a controller 3.

[0039] Preferably, the ankle action simulator 1 comprises a base 11, a foot plate 12, a left drive mechanism and a right drive mechanism, the foot plate 12 is connected to the base 11 in a universal manner for supporting a patient's foot (not shown), the left drive mechanism is hinged to the left edge of the bottom of the foot plate 12, the right drive mechanism is hinged to the right edge of the bottom of the foot plate 12, the left drive mechanism and the right drive mechanism are used to drive the foot plate 12 to move relative to the base 11 to drive the patient's foot to perform ankle rehabilitation training. Preferably, the left drive mechanism comprises a left motor 13 and a left linkage assembly 14 driven by the left motor 13, and the right drive mechanism comprises a right motor 15 and a right linkage 16 driven by the right motor 15. Preferably, the foot plate 12 and the base 1 can be connected in a universal manner through a spherical bearing, a universal bearing or a universal joint. In another preferred embodiment, a first hinge shaft extending in a first horizontal direction and a second hinge shaft extending in a second horizontal direction are provided between the foot plate 12 and the base 11, so that the foot plate 12 can rotate relative to the base 11 in the first horizontal direction and the second horizontal direction.

[0040] The ankle action correction system of the preferred embodiment of the present application has at least two training modes, including an active training mode and a passive training mode. The active training mode refers to a case where the ankle action simulator 1 allows the user to exert initiative to apply a corrective force to the ankle to correct the ankle movement to a standard action when the user has certain movement ability but the action is not standardized. The passive training mode refers to a case where the motor of the ankle action simulator 1 fits a predetermined trajectory to drive the user's ankle to move for training, and the user is in a passive state at this time.

[0041] Reference Figure 5 In the active training mode, the controller 3 performs the following steps:

[0042] Read the current data of the left motor 13 of the left drive mechanism and the current data of the right motor 15 of the right drive mechanism.

[0043] Calculate the external force F applied to the left motor 13 and the right motor 15 according to the current data of the motor. e Here, in the motor system, the external force applied to the motor is related to the motor current, and the external force can be calculated based on the correlation.

[0044] Calculate the motor position at the next moment based on the data of the external force and the current motor position Calculate the motor position at the next moment based on the data of the external force and the current motor position And send the motor position data at the next moment to the left drive mechanism and the right drive mechanism respectively.

[0045] In the passive training mode, the controller 3 calculates the next time motor position based on the preset normal ankle position curve and sends the next time motor position data to the left and right drive mechanisms respectively. Specifically, the next time motor position data includes the left and right drive mechanism motor position data.

[0046] Therefore, the left and right drive mechanisms drive the foot plate 12 to swing forward and backward relative to the base 11 or turn to the left or right based on the received next time motor position data. As Figure 2 shown is a schematic diagram of the foot plate 12 swinging forward and backward (forward tilting) relative to the base 11. As Figure 3 shown is a schematic diagram of the foot plate 12 turning to the left relative to the base 11.

[0047] In a preferred embodiment, in the active training mode, the next time motor position is calculated by the admittance control algorithm. The admittance algorithm is:

[0048]

[0049] The integral is:

[0050]

[0051] Wherein:

[0052] F e is the external force applied to the left motor of the left drive mechanism and the right motor of the right drive mechanism,

[0053] is the difference between the actual pose x of the foot plate described in the base coordinate system at time t and the expected pose x d , the actual pose x is obtained by the controller directly reading the motor, and the expected pose x d is obtained from the normal ankle position curve, is the first derivative of , and is the second derivative of , K is the stiffness coefficient diagonal matrix, B is the damping coefficient diagonal matrix, and M is the inertia coefficient diagonal matrix. K, B, and M are obtained from experimental data. Generally, the larger M is, the greater the inertia is, and too small will cause the admittance control quantity to exceed the allowed range. The larger K is, the greater the stiffness is, and too small will cause a larger tracking error. Then, according to the expected damping ε, the value of B is further obtained Increasing the damping is beneficial to weaken the rebound phenomenon.

[0054] In the above preferred embodiment, the motor control can be realized by the compliance control algorithm. The control method does not need the dynamic model of the robot, and is especially suitable for the servo control system which needs good position control effect.

[0055] In a more preferred embodiment, the controller 3 calculates the motor position at the next time Further includes the step of superimposing the chaotic interference value x n , that is, the superimposed motor position at the next time is:

[0056] Here, the chaotic interference value x n is obtained by the following chaotic formula:

[0057] h n = u * h n-1 *(1-h n-1 ) (4)

[0058] x n = A * h n (5)

[0059] Where h n is the chaotic factor at the current time, h n-1 is the chaotic factor at the previous time, the initial h0 is an arbitrary value between (0, 1) set by a person, and u is the chaotic coefficient set by the trainer. Preferably, the chaotic coefficient u is an arbitrary value between (3.5699, 4]. A is the maximum interference value set by a person.

[0060] As above, by superimposing the chaotic interference value on the motor position data at the next time, the left drive mechanism and the right drive mechanism drive the foot plate movement based on the superimposed motor position data at the next time , which can make the trainee closer to the real walking environment and further enhance the walking ability of the trainee. Here, the chaotic interference value can be superimposed in both the active training mode and the passive training mode.

[0061] Referring again to Figure 2The left and right driving mechanisms drive the foot plate 12 to swing forward and backward (pitch) based on the received motor position data of the next time. Specifically, the left driving mechanism drives the left motor 13 based on the received motor position data of the next time, and drives the left connecting rod assembly 14 to move upward by the left motor 13. Meanwhile, the right driving mechanism drives the right motor 15 based on the received motor position data of the next time, and drives the right connecting rod 16 to move upward by the right motor 15. Here, the motor position data of the next time of the left side and the motor position data of the next time of the right side are the same, so the left connecting rod assembly 14 of the left side and the right connecting rod 16 of the right side move synchronously, and can drive the foot plate 12 to pitch (rotate around the first horizontal direction axis) relative to the base 11. Of course, this is in the initial state that the foot plate 12 is horizontally arranged on the left and right sides.

[0062] Referring again to Figure 3 The left and right driving mechanisms drive the foot plate 12 to swing forward and backward (pitch) based on the received motor position data of the next time. Specifically, the left and right driving mechanisms drive the foot plate 12 to swing forward and backward (pitch) based on the received motor position data of the next time. Specifically, the left driving mechanism drives the left motor 13 based on the received motor position data of the next time, and drives the left connecting rod assembly 14 to move upward by the left motor 13. Meanwhile, the right driving mechanism drives the right motor 15 based on the received motor position data of the next time, and drives the right connecting rod 16 to move upward by the right motor 15. Here, the motor position data of the next time of the left side and the motor position data of the next time of the right side are the same, so the left connecting rod assembly 14 of the left side and the right connecting rod 16 of the right side move synchronously, and can drive the foot plate 12 to pitch (rotate around the first horizontal direction axis) relative to the base 11. Of course, this is in the initial state that the foot plate 12 is horizontally arranged on the left and right sides.

[0063] Referring again to Figures 2-4The left side driving mechanism is taken as an example to describe the connecting rod assembly in detail. Preferably, the left side connecting rod assembly 14 comprises a left side rotary connecting rod 141 and a left side lifting connecting rod 142. The first end of the left side lifting connecting rod 142 is connected with the first end of the left side rotary connecting rod 141 through a spherical hinge 143. The second end of the left side lifting connecting rod 142 is hinged with the left side edge of the bottom of the foot plate 11 along the first horizontal direction (left-right direction). The second end of the left side rotary connecting rod 141 is arranged at the driving end of the left side driving mechanism, and the left side motor 13 drives the left side rotary connecting rod 141 to rotate to lift the foot plate 11 from the left side of the foot plate 11, so that the foot plate 11 can be flipped towards the right side relative to the base 10. The right side connecting rod assembly 16 has the same structure and function as the left side connecting rod assembly 14, and will not be described here.

[0064] In a preferred embodiment, the six-dimensional force sensor 2 is arranged at the bottom of the base 11 of the ankle action simulator 1, and collects the force curve applied to the foot plate 12 of the ankle action simulator 1 during walking, for extracting gait features. Specifically, the six-dimensional force sensor 2 sends the collected data to the controller 3, and the controller 3 extracts gait features based on the pressure / torque data of the six-dimensional force sensor 2 of the foot, so as to analyze the walking condition of the user, thereby providing real-time feedback and guidance, recording the training data of the user, etc.

[0065] The ankle action simulation system of the present application cooperates with the lower limb stepping training mechanism, and can effectively simulate the joint movement of the ankle joint when the user performs the lower limb stepping training, thereby realizing the rehabilitation training of the ankle joint.

[0066] As described above, the ankle action simulation system of the present application can specifically perform the rehabilitation training of the ankle joint, and the following beneficial technical effects can be obtained:

[0067] 1. Increase walking stability and reduce pain:

[0068] Ankle joint training can enhance the muscle strength around the ankle joint. Through specific ankle joint movements such as flexion, extension, inversion and eversion, the muscle groups around the ankle joint can be activated and exercised, and their stability and control ability can be improved. The enhanced muscle strength helps to support and protect the ankle joint, reducing the pain and discomfort caused by walking.

[0069] 2. Enhance joint range of motion and flexibility:

[0070] Ankle joint training can improve the flexibility and range of motion of the ankle joint. Through a series of movements and stretching, the flow of synovial fluid can be promoted, and the joint cartilage can be lubricated, thereby improving the flexibility of the ankle joint. At the same time, it can also help to stretch and relax the surrounding muscles and ligaments, increase the range of motion of the ankle joint, and make the user more flexible and smooth when walking.

[0071] 3. Enhancing balance ability and improving safety:

[0072] Ankle joint training also helps improve the user's balance ability. Balance ability is crucial during walking, and the stability of the ankle joint plays a key role in maintaining balance. Through training, users can learn to better control the movement of the ankle joint, improve the body's sense of balance, and reduce the risk of falls caused by unstable walking.

[0073] 4. Improving gait, enhancing quality of life and self-confidence:

[0074] Ankle joint training is also important for improving the user's gait. By adjusting the position and movement pattern of the ankle joint, users can correct abnormal gait and make walking more natural and coordinated. This not only helps to reduce joint pressure and wear, but also improves walking efficiency and comfort.

[0075] In summary, the ankle action simulation system of the present application can accurately and effectively train the ankle joint, and has significant effects and benefits in walking training. It not only enhances muscle strength, improves the flexibility and range of motion of the ankle joint, but also improves balance ability and gait, providing comprehensive support and help for the user's walking training.

[0076] Obviously, those skilled in the art should realize that the above embodiments are only used to illustrate the present application, and are not used as a limitation on the present application. Any changes and modifications to the above described embodiments within the spirit and principles of the present application will fall within the scope of the claims of the present application.

Claims

1. An ankle movement correction system for rehabilitation training of the ankle joint during walking in hemiplegic patients, characterized in that, Including ankle motion simulators and controllers, The ankle movement simulator includes: a base, a foot plate, a left drive mechanism, and a right drive mechanism. The foot plate is universally connected to the base to support the patient's foot. The left drive mechanism is hinged to the left bottom edge of the foot plate, and the right drive mechanism is hinged to the right bottom edge of the foot plate. The left and right drive mechanisms drive the foot plate to move relative to the base to perform ankle joint rehabilitation training on the patient's foot. The left drive mechanism includes a left motor and a left linkage assembly driven by the left motor, and the right drive mechanism includes a right motor and a right linkage driven by the right motor. The controller is connected to the ankle motion simulator and includes an active training mode and a passive training mode. In active training mode, the controller performs the following steps: Read the current data of the left motor of the left drive mechanism and the current data of the right motor of the right drive mechanism; Calculate the external force F applied to the left motor and the right motor respectively based on the motor current data. e ; Based on the data of the external force and the current position of the motor. The motor position at the next moment is calculated. And the motor position data for the next moment is sent to the left drive mechanism and the right drive mechanism respectively; and In passive training mode, the controller calculates the motor position at the next moment based on a pre-set ankle position curve of a normal person. The motor position data for the next moment is then sent to the left drive mechanism and the right drive mechanism, respectively. The left and right drive mechanisms drive the foot plate to swing back and forth relative to the base or flip to the left or to the right based on the received motor position data at the next moment.

2. The ankle movement correction system according to claim 1, characterized in that, In the active training mode, the calculated motor position at the next moment is obtained through an admittance control algorithm.

3. The ankle movement correction system according to claim 2, characterized in that, The admittance control algorithm is as follows: Integrating, we get: in: F e The external force applied to the left motor of the left drive mechanism or the right motor of the right drive mechanism. That is, the actual pose x and the desired pose x of the foot plate described in the base coordinate system at time t. d The difference is that the actual pose x is obtained by directly reading the motor from the controller, and the desired pose x is... d It is derived from the ankle position curve of a normal person. for The first derivative, for The second 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.

4. The ankle movement correction system according to claim 1, characterized in that, The controller calculates the motor position at the next moment. This also includes superimposed chaotic disturbance values ​​x. n The next step, i.e., the motor position at the next moment, is:

5. The ankle movement correction 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 Let h be the chaos factor at the current moment. n-1 It is the chaos factor of the previous moment. The initial h0 is any value between (0,1) set by the human. u is the chaos coefficient, set by the trainer. A is the maximum disturbance value set by the human.

6. The ankle movement correction system according to claim 5, characterized in that, The chaos coefficient u is any value between (3.5699, 4).

7. The ankle movement correction system according to claim 1, characterized in that, The motor position data at the next moment includes the motor position data of the left drive mechanism and the motor position data of the right drive mechanism.

8. The ankle movement correction system according to claim 1, characterized in that, It also includes a six-dimensional force sensor, which is disposed at the bottom of the base of the ankle motion simulator.

9. The ankle movement correction system according to claim 8, characterized in that, The six-dimensional force sensor collects the curve of the force applied to the ankle motion simulator during walking and sends it to the controller for gait feature extraction.

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