Wearable robot-assisted end-effector type gait training system and control method thereof

Abstract

Provided are a robot-assisted gait training system and a method of controlling the system, wherein the training system includes a main system having a gait motion generation unit with an end-effector type robot pedal on which a patient stands for gait training and a pedal-actuating unit configured to drive the robot pedal, and a main controller configured to control the pedal-actuating unit to perform gait training of the patient standing on the robot pedal, and a collaborative system in the form of a wearable robot having at least one collaborative joint-actuating motor configured to be worn on the body of the patient and to assist or force movements of joints of a lower limb of the patient in synchronization with movements of the pedal-actuating unit, and a sub-controller configured to control the at least one joint-actuating motor so as to link or interlock movements of at least one active joint with the movements of the pedal-actuating unit according to a control signal from the main controller.

Description

Technical Field

[0001] The present disclosure relates to a wearable robot-assisted gait training system, and more particularly, to a wearable robot-assisted end-effector type gait training system that induces an inappropriate gait posture to a normal gait posture during orthopedic exercise.Background Art

[0002] A robot-assisted gait training system is a rehabilitation training apparatus for patients having difficulty walking, and is a type of gait training system mainly utilized by rehabilitation specialists. This system is designed by applying robotic technology so that a patient may practice gait and perform rehabilitation exercises.

[0003] Such a system may be adjustable to the patient's physical ability and condition, and may support gait training by simulating or assisting gait movements. In addition, the system may detect the patient's movements and, if necessary, compensate for the movements to provide safer and more efficient gait training. Through this, the system may help patients with various physical limitations to also receive rehabilitation training safely and effectively. These systems play an important role in improving patients' walking ability and restoring their independence in daily life.

[0004] The robot-assisted gait training system may be classified into two major types, which are an end-effector type gait training system and an exoskeleton robot gait training system. End-effector type gait training system: This type operates by fixing a patient's foot to a pedal that the patient may stand on, forming a gait trajectory and forcing the patient's foot movement in response to the movement of the pedal. Exoskeleton robot gait training system: This type operates by being worn on a patient's lower limb, forcibly guiding movement of the hip, knee, and ankle joints to thereby form lower limb movements.

[0005] These two types of systems may provide gait training according to the patient's condition and need, thereby supporting improvement of gait ability and rehabilitation.

[0006] Korean Application Publication No. 10-2018-0010838 (D1) discloses a lower limb training system using an exoskeleton robot. This system is composed of a wearable exoskeleton robot that leads lower limb training, a lifting unit that assists a patient's lower limb training performed by the exoskeleton robot, and a treadmill including a step board capable of moving up-and-down on which the patient's foot is placed.

[0007] In the system, the exoskeleton robot guides movement of the patient's lower limb, and the lifting unit serves to support the patient's foot to rest stably on the step board. The step board is configured to move in the up-and-down direction by the lifting unit in conjunction with movements in a forward-and-backward direction of the treadmill.

[0008] This system was designed to increase precision of the lower limb training and to more effectively support the patient's gait movement through the wearable exoskeleton robot, the lifting unit, and the step board. The system having such a structure may respond to various patient conditions and may provide a more natural gait training environment.

[0009] Korean Application Publication No. 10-2009-0104261 (D2) discloses an exoskeleton robot-based gait training system usable with a regular treadmill. The system of D2 provides a structure designed so that a patient using body weight support (BWS) trains lower limb movement via the exoskeleton robot while the patient's feet are in contact with a running belt of the treadmill. Through this, the gait training may be additionally supported.

[0010] Like the system of D1, this system operates by forcibly moving the hip, knee, and ankle joints via the exoskeleton robot worn on the patient's lower limb. In such a state, the patient may perform gait training on the treadmill, and the exoskeleton robot dominantly controls lower limb movements to maximize training effectiveness.

[0011] The system of D2 provides a gait training environment through integration of the exoskeleton robot and the treadmill, and is designed to contribute to rehabilitation of lower limb muscles and improvement of gait ability.

[0012] The gait training system using the wearable exoskeleton robot as described above has a feature of forcing movement of all joints of the lower limb, and provides a different motion mechanism compared to the end-effector type gait training system that only forces movement of the feet.

[0013] The wearable exoskeleton robot-based lower limb training system and the end-effector type gait training system may be selectively used according to a doctor's prescription depending on the patient's condition and rehabilitation goal. That is, the selection may vary according to the patient's rehabilitation training purpose, physical condition, and need.

[0014] Accordingly, each of the systems may serve as an appropriate tool for effectively achieving a specific rehabilitation purpose, and may function as an important component of a patient-customized rehabilitation program.

[0015] Korean Application Publication No. 10-2018-0041881 (D3) discloses a gait training system including a pedal operated by a fluid cylinder. This system of D3 may be classified as the end-effector type gait training system, but has a primitive structure in which a movement path of the pedal is restrictively determined by a guide groove. Therefore, because this system provides only a single gait trajectory, it is not suitable as a customized gait training system for patients requiring various gait trajectory trainings. Such a limitation may not meet needs of universal and personalized rehabilitation training that require a plurality of gait trajectories.

[0016] Korean Patent No. 10-1623686 (D4) provides an end-effector type robot-based gait training system designed by the present co-inventors. The system of D4 was designed to provide various gait trajectories by applying a 3-degree-of-freedom robot pedal capable of forward, lateral, and rotational movement.

[0017] However, a limitation of this system is that when a patient fails to adapt to a movement of the robot pedal for various reasons, control of the pedal becomes difficult accordingly. For example, when a patient who has difficulty with normal walking stands on the robot pedal, the patient's foot movement may be out of sync with each gait cycle during gait training, resulting in disharmony.

[0018] Specifically, at a mid-stance stage, when the heel of the rear foot should be lifted, the heel of the rear foot may remain attached to a floor without being lifted. This is because the patient's lower limb does not follow a normal gait pattern and, as a result, may lead to a limitation on the system's ability to provide effective gait training.

[0019] Therefore, for patients who are unable to adapt to movements of the robot pedal, a more flexible and adaptive control algorithm or complementary system design is required. Such an alternative design may appropriately meet various gait characteristics and needs of patients.Disclosure of Invention Technical Problem

[0020] The present disclosure provides a robot-assisted gait training system and a method of controlling the system, capable of effectively suppressing intervention of a therapist when joints are flexed or extended during gait rehabilitation exercise.

[0021] The present disclosure provides a robot-assisted gait training system and a method of controlling the system, capable of enhancing rehabilitation effectiveness by assisting, in real-time, movements of a patient through a wearable robot that operates in conjunction with a main system.

[0022] Specifically, the present disclosure provides a robot-assisted gait training system and a method of controlling the system, capable of preventing an injury caused by disharmony of movements of lower limb joints with respect to movements of a robot pedal during gait rehabilitation training, by generating a movement of at least one of an ankle joint, a knee joint, and a hip joint in synchronization with movements of the robot pedal, thereby promoting safe gait training.Solution to Problem

[0023] A robot-assisted walking training system according to the present disclosure includes a main system including a gait motion generation unit including a robot pedal and a pedal-actuating unit configured to drive the robot pedal, and a main controller configured to operate the pedal-actuating unit, and a collaborative system including a joint-actuating unit worn on a lower limb of a patient and comprising at least one joint-actuating motor configured to assist movements of joints of the lower limb in synchronization with movements of the pedal-actuating unit, and a sub-controller configured to control the at least one joint-actuating motor and to control movements of the at least one active joint-actuating unit in connection with the movements of the pedal-actuating unit. wherein the robot pedal may be configured to be capable of performing three-degree-of-freedom (3-DoF) movement including two linear movements in a forward-and-backward direction and an up-and-down direction, and one rotational movement with respect to a lateral axis traversing both the forward-and-backward direction and the up-and-down direction, the pedal-actuating unit may be configured to drive the robot pedal to perform the 3-DoF movement along a gait trajectory on a closed-loop, and the joint-actuating unit may be configured to forcibly move the joints of the lower limb so that movements of the patient's foot become adapted to the robot pedal when the movements of the foot are not adapted or not synchronized with the movements of the robot pedal performing the 3-DoF movement.

[0024] According to one or more embodiments, the pedal-actuating unit may include one of a joint-linkage structure having at least one joint and a plurality of links connected to each other through the at least one joint, or a bar-linkage structure in which the robot pedal moves with the robot pedal being attached to an end of an operation bar.

[0025] According to one or more embodiments, the pedal-actuating unit may include a joint-linkage structure configured to cause the 3-DoF movement of the robot pedal along the gait trajectory on the closed-loop, wherein the joint-linkage structure may include at least one joint, at least one operation link connected to the at least one joint, and at least one operation motor installed at the at least one joint and configured to drive a corresponding joint.

[0026] According to one or more embodiments, the joint-linkage structure may include an operation link having a first driving motor installed at one end thereof and configured to drive the robot pedal, a moving stage connected to another end of the operation link and on which a second driving motor for driving the operation link is mounted, a guide rail configured to support the moving stage to reciprocate in the forward-and-backward direction by a preset distance, a transfer plate on which the moving stage is mounted and which is slidably coupled to the guide rail, and a linear movement (LM) unit comprising a transfer belt coupled to the moving stage for linear reciprocating movement of the moving stage, a driving pulley and a guide pulley, both configured to support movement of the transfer belt, a third driving motor configured to provide rotational force to the driving pulley, and a power transmission unit configured to transmit power from the third driving motor to the driving pulley.

[0027] According to one or more embodiments, the pedal-actuating unit of the bar-linkage structure may include an operation bar on which the robot pedal is mounted, a closed-linkage configured to move the robot pedal along the gait trajectory on the closed-loop, and an operation motor configured to provide rotational force to the closed-linkage.

[0028] According to one or more embodiments, the joint-actuating unit of the collaborative system including a structure of a multi-joint robot may include a plurality of links positioned between the joints of the lower limb, and at least one joint-actuating motor located at the joints between the plurality of links.

[0029] According to one or more embodiments, the main controller and the sub-controller may be configured to exchange information with each other by wired or wireless communication through a communication unit, so as to enable an operation of the collaborative system to be linked with an operation of the pedal-actuating unit.

[0030] According to one or more embodiments, the joint-actuating unit of the collaborative system may include at least one joint-actuating motor from among a joint-actuating motor for assisting movement of a hip joint, a joint-actuating motor for assisting movement of a knee joint of the patient, and a joint-actuating motor for assisting movement of an ankle joint of the patient.

[0031] According to one or more embodiments, the joint-actuating unit may be configured to forcibly move the joints of the patient by the at least one joint-actuating motors, and to adjust an extent of the forced movement by the at least one joint-actuating motors based on at least one signal of a joint angle, a resistance torque, and an electromyogram of the joints of the patient, received from sensing units provided in the joint-actuating unit.

[0032] According to one or more embodiments, a pressure sensor may be further provided in the robot pedal, which is configured to detect pressure applied to the robot pedal and to transmit a pressure signal to the main controller.

[0033] According to one or more embodiments, the collaborative system may be configured to forcibly move each joint by at least one the joint-actuating motor and to adjust an extent of the forced movement of each joint by the at least one joint-actuating motor based on at least one signal of a joint angle, a resistance torque, and an electromyogram of the joint received from sensing units provided in the collaborative system.

[0034] According to one or more embodiments, the sensing units may be positioned at joint positions of the patient or positions between the joints.

[0035] In a method of controlling a robot-assisted gait training system according to the present disclosure, the gait training system may comprise a main system including a robot pedal, a gait motion generation unit including a pedal-actuating unit configured to drive the robot pedal, and a main controller configured to drive the pedal-actuating unit; and a collaborative system including a joint-actuating unit worn on a lower limb of a patient and comprising at least one joint-actuating motor configured to assist movements of joints of the lower limb in synchronization with movements of the pedal-actuating unit, and a sub-controller configured to control the at least one joint-actuating motor and to control movements of the joint-actuating unit in connection with the movements of the pedal-actuating unit, the method includes controlling, by the main system, the pedal-actuating unit to move the robot pedal along a gait trajectory on a closed-loop; causing, by the pedal-actuating unit, the robot pedal to perform three-degree-of-freedom (3-DoF) movement, including two linear movements in a forward-and-backward direction and an up-and-down direction, and one rotational movement with respect to a lateral axis traversing both the forward-and-backward direction and the up-and-down direction, and controlling, by the sub-controller, the joint-actuating unit, when movements of a foot of the patient are not adapted or not synchronized with movements of the robot pedal performing the 3-DoF movement, to forcibly move the joints of the lower limb of the patient so that the movement of the foot of the patient becomes adapted to the robot pedal.

[0036] According to one or more embodiments, the sub-controller may be configured to adjust, by using the at least one joint-actuating motor provided in the joint-actuating unit, a force for forcibly moving the joint of the lower limb of the patient based on a signal from the sensing units for detecting state information related to the movements of the joints of the patient.

[0037] According to one or more embodiments, the sensing units may be configured to detect at least one signal of a joint angle, a resistance torque, or an electromyogram of the joints of the patient's lower limb.

[0038] According to one or more embodiments, the joint-actuating unit may comprise a structure of a multi-joint robot in which a plurality of links positioned between the joints of the patient are interconnected through joints therebetween, and the sub-controller is configured to control an angle of joint movement of the lower limb of the patient as an angle between the plurality of links.

[0039] According to one or more embodiments, the robot pedal may be configured to detect a pedal pressure applied by the patient through an embedded pressure sensor and transmit the pedal pressure to the main controller, and the sub-controller is configured to receive the pedal pressure and control the joint-actuating unit. Advantageous Effects of Invention

[0040] When a patient performs rehabilitation exercise using an end-effector type robot-assisted gait training system, joints may be moved passively depending on movements of a robot, but, by linking with a collaborative system in the form of a wearable robot, real-time feedback control may be performed to control an angle of a lower limb joint of the patient and to induce voluntary muscle involvement of the patient. The end-effector type robot-assisted gait training system according to the present disclosure and the collaborative system for forcibly controlling movements of the lower limb of the patient in a preset format may interwork with each other to assist the movements of the patient through real-time feedback control. Through this, voluntary movement (muscle movement) of the patient may be induced according to an increase in rehabilitation intensity of the patient, and intervention of a therapist may be minimized, thereby improving efficiency and maximizing effectiveness of rehabilitation.Brief Description of Drawings

[0041] FIG. 1 illustrates an embodiment of a main system in a wearable robot-assisted gait training system according to the present disclosure. FIG. 2 is a side view of the main system of the wearable robot-assisted gait training system according to the present disclosure shown in FIG. 1. FIG. 3 is a front view of the main system of the wearable robot-assisted gait training system according to the present disclosure shown in FIG. 1. FIG. 4 is a perspective view illustrating a reciprocating linear movement (LM) unit and a pedal-actuating unit coupled thereto of a wearable robot-assisted gait training system according to the present disclosure. FIG. 5 is a partially enlarged perspective view illustrating, from another direction, the reciprocating LM unit and the pedal-actuating unit coupled thereto of the wearable robot-assisted gait training system shown in FIG. 4. FIG. 6 is a schematic perspective view illustrating an excerpt of a gait motion generation unit of a wearable robot-assisted gait training system according to the present disclosure. FIG. 7 show photographs of various positions (pedal positions) and postures (changes in a pedal angle) following an actual three-degree-of-freedom movement implemented in a gait motion generation unit of a wearable robot-assisted gait training system according to the present disclosure. FIG. 8 is a diagram illustrating stepwise examples of a movement following a gait trajectory of a robot pedal of a wearable robot-assisted gait training system according to the present disclosure. FIG. 9 illustrates a schematic configuration of a pedal-actuating unit of a bar-linkage structure in a wearable robot-assisted gait training system according to the present disclosure. FIG. 10 illustrates a schematic configuration of a collaborative system including a wearable active joint control robot, which is an important component of a gait training system according to the present disclosure, and a state in which a patient is wearing the same; FIG. 11 is a block diagram illustrating a control relationship between a main system of a wearable robot-assisted gait training system and a collaborative system including a wearable active joint control robot, according to the present disclosure. FIG. 12 illustrates a scene in which a patient is training while wearing a collaborative system including a wearable active joint control robot in a main system of a gait training system according to the present disclosure. FIG. 13 illustrates a normal gait cycle, showing postures of feet, knees, and thighs during a normal gait. FIG. 14 illustrates definitions of foot positions in a gait pattern. FIG. 15 illustrates a graph showing normal changes in joint angles (deg) at a hip, a knee, and an ankle during extension (ext) and flexion (flex) of joints in one gait cycle. FIG. 16 illustrates a graph showing normal changes in joint moments (N·in / kg) at a hip, a knee, and an ankle during extension and flexion of joints in one gait cycle. FIG. 16 illustrates a graph showing normal changes in joint powers (W / kg) at a hip, a knee, and an ankle during extension and flexion of joints in one gait cycle. Mode for the Invention

[0042] Hereinafter, preferred embodiments of the present inventive concept are described in detail with reference to the accompanying drawings. However, the embodiments of the present inventive concept may be modified into various other forms, and the scope of the present inventive concept shall not be construed as being limited to the embodiments described below in detail. It is desirable that the embodiments of the present inventive concept be interpreted as being provided to more fully explain the present inventive concept to one of ordinary skill in the art. The same signs denote the same elements throughout. Furthermore, various elements and areas in the drawings are schematically drawn. Therefore, the present inventive concept is not limited by the relative sizes or distances illustrated in the accompanying drawings.

[0043] Terms such as first, second, etc. may be used to describe various components, but the components are not defined by these terms. The terms are used only for distinguishing one element from another element. For example, without deviating from the scope of the claims of the present inventive concept, a first element may be referred to as a second element, and vice versa.

[0044] The terms used in the present application are used only for describing particular embodiments and are not intended to limit the present inventive concept. A singular expression may include a plural expression, unless an apparently different meaning is indicated in the context. With respect to the present application, it will be further understood that the expressions "comprises" and "comprising" used herein specify the presence of stated features, integers, steps, operations, members, components, and / or groups thereof, but do not preclude the presence or addition of one or more other features, integers, operations, members, components, and / or groups thereof.

[0045] Unless otherwise defined, all of the terms used herein including technical terms and scientific terms have the same meaning as the meaning commonly understood by one of ordinary skill in the art. Also, the terms commonly used and having the meanings as defined in dictionaries shall be understood to have consistent meanings with the corresponding terms in the context of relevant arts, and unless explicitly defined so herein, the meanings of the terms shall not be understood to be excessively formal.

[0046] In cases where an embodiment is otherwise feasible, specific process sequences may be performed in a different order than described. For example, two processes described sequentially may be performed substantially simultaneously, or may be performed in the reverse order from that described.

[0047] Hereinafter, a wearable robotic assisted gait training system and a method of controlling the gait system, according to one or more embodiments, are described below.

[0048] FIG. 1 illustrates an embodiment of a main system 100 in a wearable robot-assisted gait training system according to the present disclosure.

[0049] FIG. 2 is a side view of the wearable robot-assisted gait training system according to the present disclosure shown in FIG. 1, and FIG. 3 is a front view thereof.

[0050] The wearable robot-assisted gait training system according to the present disclosure includes the main system 100 and a collaborative system 200 in a form of a wearable active joint control robot as shown in FIG. 6 described below, and the main system 100 will be described first below.

[0051] Referring to FIGS. 1 and 2, the main system 100 is a kind of robot providing gait training to a patient and provides a gait motion generation unit 105 including two end-effector type robot pedals 105a at left and right sides, on which the patient may stand with both feet.

[0052] The main system 100 includes a first base 101a and a second base 101b at the left and right sides, which are placed on a floor to support an entire structure, and the gait motion generation unit 105 is positioned between the first base 101a and the second base 101b.

[0053] The gait motion generation unit 105 includes a first pedal-actuating unit 105L and a second pedal-actuating unit 105R at the left and right sides, to which each of the robot pedals 105a at the left and right sides is coupled. Each of the first pedal-actuating unit 105L and the second pedal-actuating unit 105R includes the robot pedal 105a, a first operation link 105b to which the robot pedal 105a is operably coupled via a first driving motor 105d, and the first operation link 105b includes the first driving motor 105d for rotating the robot pedal 105a within a preset angle range based on an individual training plan and is connected to and rotated by a second driving motor 105c provided on each of the left and right first and second bases 101a and 101b.

[0054] The second driving motor 105c for rotating the first operation link 105b within a preset angle range is coupled to a moving stage 108s of a reciprocating linear movement (LM) unit 108 (see FIGS. 4A and 4B) described below and may perform reciprocating linear movement along the corresponding first base 101a or second base 101b. Further details are provided in the description of FIGS. 4A and 4B.

[0055] Each of the robot pedals 105a of the first and second pedal-actuating units 105L and 105R of the left and right sides, which are disposed between the first and second bases 101a and 101b of the left and right sides, may move in correspondence with movement trajectories of both left and right feet during gait, for example, such that the soles of the feet are stably placed on upper surfaces of the robot pedals and both the robot pedals 105a move harmoniously with each other, and in some cases, may intentionally move disharmoniously.

[0056] The robot pedals 105a are moved by a system control unit described below to enable a patient to perform a walking exercise suitable for the patient, and the patient may stand on the robot pedals and perform the walking exercise by conforming to movements of the robot pedals 105a. An ankle band that may be installed on each of the robot pedals fixes a patient's foot thereto, either loosely or tightly, so that the foot may move within a certain range on the robot pedal.

[0057] The movement of the two robot pedals 105a is for gait training of a patient, and is controlled by the system control unit to train the patient's gait, while accommodating an abnormal gait pattern, to bring this gait pattern closer to a normal gait pattern.

[0058] In addition to such operation components, as shown in FIGS. 1 to 3, in front of the gait motion generation unit 105, an assembly in which a saddle 104 and a safety bar 106 thereon or a fence unit 107 supporting the chest and the like including the safety bar 106 are combined as one, is provided, and this assembly is mounted to a lifting unit 102 through an up-and-down frame 103. The lifting unit 102 is a lifting and lowering device for the assembly, which is configured to adjust a height of the assembly to suit physical conditions of a patient. At an upper end of the lifting unit 102, a system status display unit 109 facing a patient is provided.

[0059] At a foremost part of the main system 100, where the patient is looking, a lifting or fixed support column 113A is installed, and a system monitor 113 for displaying an overall operation state of the system as a whole is coupled thereto.

[0060] FIGS. 4 and 5 illustrate structures and coupling relationships of the LM unit 108 described above and the pedal-actuating units 105L and 105R, each coupled thereto.

[0061] First, referring to the LM unit 108, two upper and lower guide rails 108r, which are parallel in a longitudinal direction, are installed on a base frame 108f, and a transfer plate 108c is coupled to the two guide rails 108r via an LM guide 108g so as to be capable of linear movement, and the moving stage 108s, on which the second driving motor 105c for driving an operation link 105b is mounted, is integrally coupled to the transfer plate 108c, and thus configured to move together with the transfer plate 108c in a first linear movement LM1.

[0062] The moving stage 108s is connected to an endless belt, for example, a transfer belt 108b1, installed in the longitudinal direction of the base frame 108f, a same direction as the guide rails 108r, and the transfer belt 108b1 is engaged with a driven pulley 108p1 and a guide pulley 108p2 so that endless movement between the pulleys is possible. The driven pulley 108p1 and the guide pulley 108p2 are arranged in the movement direction of the moving stage 108s, and a part of the transfer belt 108b1, movement of which is guided by the pulleys, may be coupled to the moving stage 108s or the transfer plate 108c.

[0063] A third driving motor 108m is installed at one side (left side in FIG. 4) of the base frame 108f, and rotational force of the third driving motor 108m is transmitted to the driven pulley 108p1 through a powertrain unit 108t. In this embodiment, the driven pulley 108p1, as one element of the powertrain unit 108t, is coaxially and integrally coupled with a planetary pulley 108p3 that receives power from a driving pulley 108p4 of the third driving motor 108m through a driving belt 108b2.

[0064] In this embodiment, a power transmission structure employs a pulley and a belt of which movement is guided by the pulley, but a technical scope of the present disclosure is not limited by such a specific power transmission structure.

[0065] FIG. 6 is a perspective view illustrating an excerpt of the gait motion generation unit 105.

[0066] As shown in FIG. 6, movement of the robot pedal 105a may occur in three directions with three-degree-of-freedom. Such a movement occurs as a combination of a first rotational movement, a second rotational movement, and a first linear movement.

[0067] In the three-degree-of-freedom movement, a first rotational movement RM1 is rotational movement of the robot pedal 105a with respect to the moving stage (see FIG. 5), a second rotational movement RM2 is rotational movement of the robot pedal 105a with respect to the operation link 105b by the first driving motor 105d, and the first linear movement LM1 is linear movement of the second driving motor 105c by the moving stage 108s of the LM unit 108.

[0068] Further, according to an appropriate combination of the first rotational movement RM1 and the second rotational movement RM2, a second linear movement LM2 in an up-and-down direction of the robot pedal 105a may be generated.

[0069] Therefore, according to the above two rotational movements and two linear movements, the robot pedals 105a are moved by one rotational movement and two linear movements.

[0070] As a result, such robot pedals 105a move along a closed-loop movement trajectory by the combined movement of one rotational movement and two linear movements, and at this time, the angles of the robot pedals 105a and 105b are changed, thereby forcing the ankle angle of a patient.

[0071] Such combined movement may force movement of a foot of the patient so that, accordingly, all joints of the lower limb of the patient, namely, a hip joint, a knee joint, and an ankle joint, are caused to be operated in response to a position and posture of the foot, thereby inducing normal gait of the patient.

[0072] Meanwhile, each of the robot pedals 105a is coupled to the operation link 105b via the first driving motor 105d so as to enable a preset rotational movement RM2 of a preset angle with respect to the operation link 105b, and a band (not shown) for binding a patient's foot or ankle, or a clamp or cleat structure for fixing the patient's shoe and the robot pedal, may be provided in the robot pedal.

[0073] The combined up-and-down and forward-and-backward movement of each of the two robot pedals 105a of the gait motion generation unit 105 is performed independently, but during gait, the left and right feet are forced to move apart or approach each other and may intersect in response to the movements of both feet. In order to achieve such a combined movement, a structure different from the above-described specific structure may be applied. For example, a driving unit for linear movement, which may control linear reciprocating movement of the operation link or the entire gait motion generation unit 105 having the operation link, and a driving unit for rotation or rotational movement, which may control the rotational movement of the operation link 105b, may have various forms.

[0074] The gait motion generation unit 105 described above has been described in great detail as having a structure for driving the robot pedal 105a, including the operation link 105b, the first driving motor 105d, the second driving motor 105c, and the LM unit 108, but it should be understood that the technical scope of the present disclosure is not limited to such a specific structure of the gait motion generation unit 105.

[0075] FIG. 7 show photographs of various positions (pedal positions) and postures (changes in a pedal angle) according to actual three-degree-of-freedom movement implemented in the gait motion generation unit 105 of the wearable robot-assisted gait training system according to the present disclosure.

[0076] As shown in FIG. 7, the robot pedal on which a patient stands performs the three-degree-of-freedom movement, including movement in the forward-and-backward direction, the up-and-down direction, and the rotational movement about a lateral axis orthogonal to both directions. Such a three-degree-of-freedom movement is configured to cause the patient's feet to move in the forward-and-backward directions and the up-and-down directions, and simultaneously induces rotation of the ankle joint.

[0077] That is, the robot pedal is capable of the three-degree-of-freedom movement composed of two linear movements and one rotational movement. Here, the two linear movements each include movement in the forward-and-backward direction and the up-and-down direction, and the one rotational movement is performed about a lateral axis traversing both the forward-and-backward direction and the up-and-down direction.

[0078] The three-degree-of-freedom movement is designed to reproduce a natural movement of the patient's ankle and lower limb joints and maximize the effectiveness of gait training.

[0079] FIG. 8 illustrates changes in position and posture during the process in which a robot pedal moves along a gait trajectory 105gt in the wearable robot-assisted gait training system according to the present disclosure.

[0080] As shown in FIG. 8, the robot pedal 105a, when moving along the gait trajectory 105gt with two linear movements LM1 and LM2 and two rotational movements RM1 and RM2, has continuously changing positions and postures (angles) along the gait trajectory 105gt. The movement trajectory of the robot pedal and the angles changing along the trajectory are presented as the gait training trajectory for patient training, and a goal of gait training is to ultimately make the gait training trajectory converge to a gait trajectory of a normal walker.

[0081] According to another embodiment of the present disclosure, a gait motion generation unit for driving a three-degree-of-freedom end-effector type robot pedal directly involved in patient gait training may, in order to implement patient gait, employ a joint-linkage structure having a plurality of joints and links and in which the robot pedal is mounted at an end and is capable of linear or rotational movement, or a bar-linkage structure in which the robot pedal is mounted at an end of an operation bar and is capable of movement. Additionally, for example, a rail-assisted bar-linkage structure, in which a rail for guiding movement of the robot pedal is added to the bar-linkage structure in which the robot pedal is mounted at the end of the operation bar to move, may be adopted, and this is also within the scope of the present disclosure.

[0082] FIG. 9 schematically and conceptually illustrates a simplified configuration of a three-degree-of-freedom end-effector type gait training system having a gait motion generation unit of the bar-linkage structure.

[0083] Referring to FIG. 9, the gait motion generation unit has two bar-linkage structures 302 on the left and right, whereas one bar-linkage structure 302 is shown. Each bar-linkage structure 302 includes two long operation bars directly operated by an operation motor 307, that is, an first operation bar 302c and a second operation bar 302d.

[0084] In the gait motion generation unit of the bar-linkage structure, one end (the left side in the drawing) of the first operation bar 302c and the second operation bar 302d, which are elements of a closed-linkage, is configured to be directly operated by the operation motor 307. Here, one end of the first operation bar 302c is rotatably connected to a rotating wheel 306a or a rotating arm 306 rotated by the operation motor 307, and the second operation bar 302d contacts a rotating cam 305 rotated by the operation motor 307 and slides while rotating up and down according to the change in contact position with the rotating cam 305.

[0085] At the other end (the right side in the drawing) of the first operation bar 302c and the second operation bar 302d, both ends of a short third operation rod or a actuating plate 302a, on which a foot plate or robot pedal 301 is installed, are rotatably interconnected.

[0086] According to this structure, the rotating wheel 306a and the rotating cam 305 are rotated by the operation motor 307, and the first operation bar 302c and the second operation bar 302d move correspondingly to rotational movements of the rotating wheel and the rotating cam. Accordingly, at a front end where the robot pedal 301 is located, the actuating plate 302a moves from side to side and slightly rises and falls, thereby forming the movement of the robot pedal 301 along the trajectory as indicated by reference numeral "304", and thus enabling a patient 1 to perform gait training by stepping on the robot pedal.

[0087] Such a pedal-actuating unit of the bar-linkage structure shown in FIG. 9 has the actuating plate provided with the robot pedal, the closed-linkage structure by the first operation bar and the second operation bar, and the operation motor that operates them.

[0088] The pedal-actuating unit of the bar-linkage structure illustrated in FIG. 9 merely describes a basic framework of the bar-linkage structure, and the bar-linkage structure may be modified or improved in various forms, and the technical scope of the present disclosure is not limited by such a specific structure.

[0089] The gait training by means of such robot pedals is suitable for patients who are able to adapt to the robot pedal to some extent. However, for patients who still have difficulty standing on the robot pedals to perform training, for example, for a case in which the movement of the lower limbs does not reach a certain level and a collaborative system is therefore required to forcibly adapt, fit, or harmonize the lower limbs to the movement of the robot pedals for gait training, the present disclosure provides such a system.

[0090] The collaborative system is applied when the patient's lower limbs are weak or unstable, and when the movement of the patient's feet fixed to the robot pedals for gait training does not conform to or follow the movement of the robot pedals. That is, when the movement of the patient's feet does not adapt or conform to the movement of the robot pedals, the joint movement of the lower limb may be forced so that the patient's feet are adapted or coordinated to the robot pedals.

[0091] For example, forced training may be performed on patients who cannot properly move their lower limbs, and according to such forced training, even if the patient's feet may not be able to be properly attached to the pedals, the patient's feet may be forcibly attached to the pedals by forced training. The collaborative system appropriately forces the movement of the joints of the lower limbs with a controlled force, so as to adapt, in particular, the movement of the sole of the foot to the robot foot plate, and is a collaborative system for gait training that forces the movement of the joints of the lower limbs rather than for gait training itself. FIG. 10 illustrates a schematic structure of the collaborative system 200, which is an important component of the gait training system according to the present disclosure and is equipped with a wearable active joint control robot, and a state in which the patient 1 is wearing the collaborative system 200.

[0092] The collaborative system 200 according to the present disclosure, as illustrated in FIG. 10, may be designed and manufactured so that both legs of a patient may undergo forced training in response to the movement of the robot pedals during gait training, but in some embodiments, the collaborative system 200 may be applied to only one leg.

[0093] The collaborative system 200 having an active joint control robot structure, only one portion of which is illustrated in FIG. 10, includes a wearing band 201 attached or fixed to the body of the patient 1, for example, the waist, and a first joint-actuating unit 200L on the left and a second joint-actuating unit 200R on the right, which correspond to the left and right lower limbs below the waist. Each of the joint-actuating units 200L and 200R is provided below the wearing band 201 and includes a plurality of links (three in the drawing) connected from the waist to the foot, that is, a first link 205 between the waist belt part and the hip joint, a second link 206 between the hip joint and the knee, a third link 207 between the knee and the ankle joint, and, if necessary, optionally a foot fixing part 208, which may be added or omitted as needed and according to design requirements. Here, the foot fixing part 208 may be designed so that a pressure from the sole of the foot is transmitted to the robot foot plate, but only the ankle joint angle with respect to the third link 207 may be controlled.

[0094] Active joint control components for active joint control, that is, joint-actuating motors 202, 203, and 204, are provided between each of the links. These joint-actuating motors 202, 203, and 204, that is, actuators, may be provided as various actuators such as rotary motors or reciprocating fluid cylinders, and may include sensing units 212, 213, and 214 for measuring a joint angle, a resistance torque, an electromyography, or the like. The joint-actuating motors 202, 203, and 204 actively control an angle or a torque, or both an angle and a torque, of a lower link with respect to an upper link, between corresponding upper and lower links. Such control is flexible and forces a joint between the corresponding links to be maintained within an arbitrary range. Such active joint control elements are controlled by the controller of the main system 100, and their operation is synchronized with the movement of the robot pedal, for example, in accordance with a gait cycle pattern, but may be controlled to be intentionally unsynchronized depending on a training program.

[0095] The collaborative system 200 assists gait training using the three-degree-of-freedom robot pedal, so that even a patient with weak lower limbs may perform gait training using the robot pedal.

[0096] FIG. 11 is a block diagram showing a control relationship between the main system 100 and the collaborative system 200 including the wearable active joint control robot.

[0097] As shown, the main system 100 and the collaborative system 200 are connected through a communication unit 198, so that instructions from the main system 100 are transmitted to the collaborative system 200 and results are returned to the main system 100.

[0098] The communication unit 198 may employ various short-range communication methods, and for example, Bluetooth may be applied. The communication unit 198 is provided as a representative communication unit as a symbolic element, and as illustrated, a main controller 199 and a collaborative controller 210 may be connected through the communication unit 198.

[0099] The first sensing unit 212, the second sensing unit 213, and the third sensing unit 214 measure patient's joint angles, joint resistance torques, electromyography values, or the like, and the measured values are transmitted to the main controller 199 through the communication unit 198.

[0100] The first, second, and third sensing units 212, 213, and 214 may be provided for each of the joint-actuating motors 202, 203, and 204, and in another embodiment, may be provided between the joint-actuating motors.

[0101] The collaborative controller 210 may control the joint-actuating motors 202, 203, and 204 of the joint-actuating units 200L and 200R that force the angles of the lower limb joints of the patient 1 as described above. The collaborative controller 210 may control the first joint-actuating motor 202 for the hip joint, the second joint-actuating motor 203 for the knee joint, and the third joint-actuating motor 204 for the ankle joint, and such joint-actuating motors, that is, actuators, may be added or omitted as needed and according to design.

[0102] FIG. 12 illustrates a scene in which the patient 1 is trained while wearing the robot-type collaborative system 200 in the main system 100 according to the present disclosure. As shown in FIG. 12, for example, in the case of a severe patient, the patient 1 may perform gait training while wearing the collaborative system 200, that is, the wearable robot, sitting on the saddle 104 and holding the safety bar 106. Depending on a condition of the patient 1, for example, in the case of a mild patient, the saddle 104 may be folded, so the patient 1 may perform gait training without relying on the saddle 104, and this allows a training plan to be followed according to the patient's condition.

[0103] The robot pedal 105a may be operated by the main controller 199 to force gaits of the patient 1 regardless of the patient's intention. At this time, a pressure sensor or the like is installed on the saddle 104 and the robot pedal 105a, so that a load applied to the saddle 104 and a load applied to the robot pedal during gait training may be detected. In particular, a plurality of pressure sensors are provided at a front and rear of the robot pedal to detect a local pressure applied to the robot pedal and to detect degrees of pressing or contact of the sole of the foot on the robot pedal.

[0104] The robot pedal may detect pedal pressures applied by the patient through the built-in pressure sensor, may transmit the pedal pressure to the main controller, and the collaborative controller may control the joint-actuating unit by receiving the pedal pressure.

[0105] In this process, the collaborative system 200, together with the progress of the patient's training by the main system 100, may forcibly move one or more joints with an appropriately controlled force using the actuating units of the collaborative system 200, and, as a result, the degree of forced movement of the relevant joint may be controlled based on at least one of the values of the joint angle, the resistance torque, and the electromyography, at least one of which is received from the sensing units.

[0106] FIG. 13 illustrates a normal gait cycle referenced for gait training for patients, showing postures of feet, knees, and thighs during a normal gait, and FIG. 14 illustrates definitions for each position in a gait pattern.

[0107] Referring to FIG. 13, in an entire single gait cycle, stance phase is a period during which a foot is in contact with a ground, and swing phase is a period during which the foot is off the ground.

[0108] Each gait cycle includes the following three tasks.1. Weight Acceptance

[0109] This period includes an initial contact period (when a foot first contacts a ground) and a loading response period (when a sole strikes the ground).2. Single Limb Support

[0110] This is midstance period, during which the sole is on the ground and the foot of an opposite leg leaves the ground, while the opposite leg swings with the heel thereof being lifted..3. Limb Advancement

[0111] This period includes pre-swing, in which a rear foot leaves the ground with the toe thereof leaving the ground, and a leading foot makes contact with the ground, mid swing, in which a previously grounded foot begins to leave the ground while both feet are close together, and terminal swing, in which a heel of a leading foot begins to touch the ground as the rear foot pushes forward.

[0112] The gait pattern described above is the normal gait pattern, and patients are trained to achieve this normal gait pattern. However, in patients who have difficulty walking normally, the patient's feet may move out of sync with each cycle during the gait training. For example, in the midstance period, when the heel of a rear foot is expected to rise, the heel may still remain on the ground without lifting off. This is because the patient's body does not follow the normal gait pattern, and the robot-type collaborative system 200 of the present disclosure may forcibly bend the knee joint or ankle joint with controlled force at this time so that the heel of the rear foot is lifted from the ground in accordance with the patient's gait pattern. Such forced joint movements may be applied at every phase, so that the patient undergoing the gait training may be forced to have at least a similar normal gait pattern despite their own physical limitations.

[0113] FIG. 14 illustrates definitions of foot positions in the gait pattern as previously described, and FIGS. 15, 16, and 17 show graphs representing normal changes in joint angles (degrees), joint moments (N·m / kg), and joint powers (W / kg) of a hip, a knee, and an ankle when extending (ext) and flexing (flex) joints during a single gait cycle. In the graphs of FIGS. 15, 16, and 17, IC refers the initial contact (heel strike), OT refers the opposite toe off in, HR refers the heel rise, and OI means the opposite initial contact.

[0114] Referring to FIGS. 14 to 17, normal states of foot positions in the gait pattern are as follows. A. Initial contact (heel strike) 1. Hip joint angle: about 30 degrees (flexion). B. Loading response 1. Hip joint: around 25 degrees (flexion) 2. Knee joint: about 10 degrees (flexion) 3. Ankle joint: about 10 degrees (plantar flexion) C. Mid stance 1. Hip joint: 25 degrees (flexion) to 10 degrees (extension) 2. Knee joint: peak (flexion) to about 0 degrees 3. Ankle joint: changing to dorsiflexion D. Heel rise (heel off) 1. Hip joint: -10 degrees (continues to extension) 2. Knee joint: extension peak 3. Ankle joint: 0 degrees E. Toe off, terminal contact 1. Hip joint: -20 degrees to 20 degrees (continues to flex) 2. Knee joint: 20 degrees (continues to flex) 3. Ankle joint: plantar flexion peak F. Initial swing to mid swing 1. Hip joint: 20 degrees to 30 degrees (continues to flex) 2. Knee joint: 60 degrees (flexion peak) to 30 degrees 3. Ankle joint: 10 degrees to 0 degrees

[0115] Based on the above normal states of the foot, the training system according to the present disclosure may perform the gait training for patients with the robot pedal, aiming for the above normal ranges.

[0116] In an embodiment of the present disclosure, by using the collaborative system in the form of the wearable robot synchronized with the operation of the gait motion generation unit of the main system, the forced control of angles of the hip joint, the knee joint, the ankle joint, etc., and the forced control of the flexion and extension of the patient's joints, by considering for example the normal flexion and extension angles, may be performed so that so-called back-knee phenomena may be prevented and rehabilitation effects may be enhanced. In addition, by forcibly controlling the angle of the knee of the patient to be within the normal range, it may be possible to prevent the heel from leaving the ground early during midstance.

[0117] Here, the wearable collaborative system conceptually illustrated in FIG. 10 may be implemented in various forms, specifically in any form that may forcibly control at least one of the lower limb joints of the patient in compliance with the control of the main system, and such actual implementations having the above control structure may be understood to fall within the scope of the present disclosure. In addition, as described above, the gait motion generation unit for driving the end-effector type robot pedal may have the structure in which the robot pedal is provided with the operation link, the first and second operation motor, and the LM unit, and in some embodiments, the gait motion generation unit may adopt the bar-linkage structure in which the robot pedal is attached to the end of the operation bar or the rail-assisted bar-linkage structure in which the rail for guiding the movement of the robot pedal is added to the bar-linkage structure, and this is also, of course, within the scope of the present disclosure.

[0118] As described above, although example embodiments of the present disclosure have been described in detail, those of ordinary skill in the art will understand that various modifications may be made without departing from the spirit and scope of the present disclosure as defined by the appended claims. Therefore, changes to future embodiments of the present disclosure will not depart from the technical scope of the present disclosure.

Claims

1. A robot-assisted gait training system comprising: a main system including a gait motion generation unit including a robot pedal and a pedal-actuating unit configured to drive the robot pedal, and a main controller configured to operate the pedal-actuating unit; and a collaborative system including a joint-actuating unit worn on a lower limb of a patient and comprising at least one joint-actuating motor configured to assist movements of joints of the lower limb in synchronization with movements of the pedal-actuating unit, and a sub-controller configured to control the at least one joint-actuating motor and to control movements of the at least one active joint-actuating unit in connection with the movements of the pedal-actuating unit, wherein the robot pedal is configured to be capable of performing three-degree-of-freedom (3-DoF) movement including two linear movements in a forward-and-backward direction and an up-and-down direction, and one rotational movement with respect to a lateral axis traversing both the forward-and-backward direction and the up-and-down direction, wherein the pedal-actuating unit is configured to drive the robot pedal to perform the 3-DoF movement along a gait trajectory on a closed-loop, and wherein the joint-actuating unit is configured to forcibly move the joints of the lower limb so that movements of the patient's foot become adapted to the robot pedal when the movements of the foot are not adapted or not synchronized with the movements of the robot pedal performing the 3-DoF movement.

2. The robot-assisted gait training system of claim 1, wherein the pedal-actuating unit includes one of: a joint-linkage structure having at least one joint and a plurality of linkage connected to each other through the at least one joint; or a bar-linkage structure in which the robot pedal moves with the robot pedal being attached to an end of an operation bar.

3. The robot-assisted gait training system of claim 1, wherein the pedal-actuating unit includes a joint-linkage structure configured to cause the 3-DoF movement of the robot pedal along the gait trajectory on the closed-loop, wherein the joint-linkage structure includes: at least one joint; at least one operation link connected to the at least one joint; and at least one operation motor installed at the at least one joint and configured to drive a corresponding joint.

4. The robot-assisted gait training system of claim 3, wherein the joint-linkage structure includes: an operation link having a first driving motor installed at one end thereof and configured to drive the robot pedal; a moving stage connected to another end of the operation link and on which a second driving motor for driving the operation link is mounted; a guide rail configured to support the moving station to reciprocate in the forward-and-backward direction by a preset distance; a transfer plate on which the moving station is mounted and which is slidably coupled to the guide rail; and a linear movement (LM) unit comprising a belt coupled to the moving station for linear reciprocating movement of the moving station, a driving pulley and a guide pulley, both configured to support a movement of the belt, a third driving motor configured to provide rotational force to the driving pulley, and a power transmission unit configured to transmit power from the third driving motor to the driving pulley.

5. The robot-assisted gait training system of claim 3, wherein the pedal-actuating unit of the bar-linkage structure comprises: an operation bar on which the robot pedal is mounted; a closed-linkage configured to move the robot pedal along the gait trajectory on the closed-loop; and an operation motor configured to provide rotational force to the closed-linkage.

6. The robot-assisted gait training system of claim 1, wherein the joint-actuating unit of the collaborative system having a structure of a multi-joint robot includes: a plurality of links positioned between the joints of the lower limb; and a structure of a multi-joint robot having the at least one joint-actuating motor located at the joints between the plurality of links.

7. The robot-assisted gait training system of any one of claims 1 to 6, wherein the main controller and the sub-controller are configured to exchange information with each other by wired or wireless communication through a communication unit, so as to enable an operation of the collaborative system to be linked with an operation of the pedal-actuating unit.

8. The robot-assisted gait training system of 6, wherein the joint-actuating unit of the collaborative system comprises at least one joint-actuating motor from among a joint-actuating motor for assisting movement of a hip joint, a joint-actuating motor for assisting movement of a knee joint of the patient, and a joint-actuating motor for assisting movement of an ankle joint of the patient.

9. The robot-assisted gait training system of claim 7, wherein the joint-actuating unit is configured to forcibly move the joints of the patient by the at least one joint-actuating motor, and to adjust an extent of the forced movement by the at least one joint-actuating motor based on at least one signal of a joint angle, a resistance torque, and an electromyogram of the joints of the patient, received from sensing units provided in the joint-actuating unit.

10. The robot-assisted gait training system of 9, further comprising a pressure sensor provided in the robot pedal and configured to detect pressure applied to the robot pedal and to transmit a pressure signal to the main controller.

11. The robot-assisted gait training system of any one of claims 1 to 6, wherein the collaborative system is configured to forcibly move each joint by the at least one joint-actuating motor and to adjust an extent of the forced movement of each joint by the at least one joint-actuating motor based on at least one signal of a joint angle, a resistance torque, and an electromyogram of the joints received from sensing units provided in the collaborative system.

12. The robot-assisted gait training system of claim 10, wherein the sensing units are positioned at joint positions of the patient or positions between the joints.

13. A method of controlling a robot-assisted gait training system, wherein the gait training system comprises: a main system including a robot pedal, a gait motion generation unit including a pedal-actuating unit configured to drive the robot pedal, and a main controller configured to drive the pedal-actuating unit; and a collaborative system including a joint-actuating unit worn on a lower limb of a patient and comprising at least one joint-actuating motor configured to assist movements of joints of the lower limb in synchronization with movements of the pedal-actuating unit, and a sub-controller configured to control the at least one joint-actuating motor and to control movements of the joint-actuating unit in connection with the movements of the pedal-actuating unit, wherein the method comprises: controlling, by the main system, the pedal-actuating unit to move the robot pedal along a gait trajectory on a closed-loop; causing, by the pedal-actuating unit, the robot pedal to perform three-degree-of-freedom (3-DoF) movement, including two linear movements in a forward-and-backward direction and an up-and-down direction, and one rotational movement with respect to a lateral axis traversing both the forward-and-backward direction and the up-and-down direction; and controlling, by the sub-controller, the joint-actuating unit, when movements of a foot of the patient are not adapted or not synchronized with movements of the robot pedal performing the 3-DoF movement, to forcibly move the joints of the lower limb of the patient so that the movements of the foot of the patient become adapted to the robot pedal.

14. The method of claim 13, wherein the sub-controller is configured to adjust, by using the at least one joint-actuating motor provided in the joint-actuating unit, a force for forcibly moving the joints of the lower limb of the patient based on a signal from sensing units for detecting state information related to the movements of the joints of the patient.

15. The method of claim 14, wherein the sensing units are configured to detect at least one signal of a joint angle, a resistance torque, or an electromyogram of the joints of the patient's lower limb.

16. The method of claim 13, wherein the joint-actuating unit has a structure of a multi-joint robot in which a plurality of links positioned correspondingly between the joints of the patient are interconnected through joints therebetween, and the sub-controller is configured to control an angle of joint movement of the lower limb of the patient as an angle between the plurality of links.

17. The method of claim 14, wherein the joint-actuating unit has a structure of a multi-joint robot in which a plurality of links positioned between the joints of the patient are interconnected through the joints, and the sub-controller is configured to control an angle of joint movement of the lower limb of the patient as an angle between the plurality of links.

18. The method of claim 15, wherein the joint-actuating unit comprises a structure of a multi-joint robot in which a plurality of links positioned between the joints of the patient are interconnected through joints therebetween, and the sub-controller is configured to control an angle of joint movement of the lower limb of the patient as an angle between the plurality of links.

19. The method of claim 13, wherein the robot pedal is configured to detect a pedal pressure applied by the patient through an embedded pressure sensor and transmit the pedal pressure to the main controller, and the sub-controller is configured to receive the pedal pressure and control the joint-actuating unit.

20. The method of claim 15, wherein the robot pedal is configured to detect a pedal pressure applied by the patient through an embedded pressure sensor and transmit the pedal pressure to the main controller, and the sub-controller is configured to receive the pedal pressure and control the joint-actuating unit.

Images