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

Abstract

Disclosed are a robot-assisted gait training system and a control method thereof. An exercise system according to the present invention includes: a main system including a gait motion generation unit, having an end-effector type robot pedal on which a patient steps and stands for gait training and a pedal-actuating unit for driving the robot pedal, and a main control unit for controlling the pedal-actuating unit to perform the gait training of the patient standing on the robot pedal; and a cooperative system including one or more cooperative joint-actuating motors that are mounted on the body of the patient and assist or force lower body joint movements of the patient in synchronization with the movements of the pedal-actuating unit, the cooperative system in the form of a wearable robot and provided with a sub-control unit for controlling the one or more joint-actuating motors and associating or linking movements of one or more active joint units with the movements of the pedal-actuating unit using control signals from the main control unit.

Description

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

[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.

[0002] The Robot-Assisted Gait Training System is a rehabilitation training device for patients with walking difficulties. It is a type of gait training system primarily utilized by rehabilitation specialists. This system utilizes robotic technology to help patients practice walking and perform rehabilitation exercises.

[0003] These systems can be adjusted to the patient's physical abilities and condition, and support gait training by simulating or assisting walking movements. They also detect the patient's movements and compensate for them as needed, providing safer and more efficient gait training. This allows patients with various physical limitations to safely and effectively undergo rehabilitation training. These systems play a crucial role in improving patients' walking ability and restoring independence in daily life.

[0004] Robot-assisted gait training systems are divided into two main types: end-effector type gait training systems and exoskeleton type robotic gait training systems.

[0005] - End-effector type gait training system: This type operates by forming a gait trajectory by fixing the patient's feet to pedals that the patient can step on, and forcing the patient's feet to move according to the movement of the pedals.

[0006] - Exoskeleton type robot gait training system: This type is worn on the patient's lower limbs and works by forcibly inducing movement of the hip, knee, and ankle joints, thereby forming lower limb movements.

[0007] These two types of systems each provide gait training tailored to the patient's condition and needs, helping to improve walking ability and assist with rehabilitation.

[0008] Korean Patent Publication No. 10-2018-0010838 (D1) presents a lower limb training system utilizing an exoskeleton robot. This system comprises a wearable exoskeleton robot that facilitates lower limb training, an elevating device that assists the patient's lower limb training performed by the exoskeleton robot, and a treadmill that includes a step board for the patient's feet.

[0009] In this system, an exoskeleton robot guides the patient's lower extremity movements, while a lifting device supports the patient's feet so they are stably positioned on the footrest. The footrest is designed to move up and down, in sync with the treadmill's forward-backward movement.

[0010] This system is designed to enhance the precision of lower extremity training and more effectively support the patient's walking movements through a wearable exoskeleton robot, a lifting device, and a lifting / lowering platform. This structure adapts to a variety of patient conditions and provides a more natural gait training environment.

[0011] Korean Patent Publication No. 10-2009-0104261 (D2) discloses a gait training system based on an exoskeleton robot suitable for use on a standard treadmill. The D2 system features a structure designed to allow a patient using a body weight support (BWS) to train lower extremity movements using an exoskeleton robot, while simultaneously allowing the patient's feet to contact the treadmill's running belt. This allows for gait training to be performed as a secondary benefit.

[0012] Similar to D1, this system operates by forcing movement of the hip, knee, and ankle joints through an exoskeleton robot worn on the patient's lower extremities. The patient performs gait training on a treadmill, while the exoskeleton actively controls lower extremity movement, maximizing the effectiveness of the training.

[0013] D2's system provides a walking training environment through the integration of an exoskeleton robot and a treadmill, and is designed to contribute to the rehabilitation of lower extremity muscles and improvement of walking ability.

[0014] The gait training system utilizing the above-mentioned wearable exoskeleton robot has the characteristic of forcing movement of the entire lower limb joint, which provides a different exercise mechanism from the end-effector type gait training system that forces movement of only the patient's feet.

[0015] The wearable exoskeleton-based lower extremity training system and the end-effector-based gait training system can be selectively utilized based on a physician's prescription, depending on the patient's condition and rehabilitation goals. In other words, the choice may vary depending on the patient's rehabilitation training goals, physical condition, and needs.

[0016] Therefore, each system can be utilized as an appropriate tool to effectively achieve specific rehabilitation goals and serves as an important component of a patient-tailored rehabilitation program.

[0017] Korean Patent Publication No. 10-2018-0041881 (hereinafter, D3) discloses a gait training system that includes a pedal operated by a fluid cylinder. While this system can be classified as an end-effector type gait training system, it has a primitive structure in which the pedal's movement path is limited by guide grooves. Therefore, this system only provides a single gait trajectory, making it unsuitable as a personalized gait training system for patients requiring training in a variety of gait trajectories. This limitation fails to meet the needs of universal and personalized rehabilitation training that requires multiple gait trajectories.

[0018] Korean Patent No. 10-1623686 (D4) presents a gait training system based on an end-effector-type gait rehabilitation robot designed by the present co-inventors. The D4 system utilizes a three-degree-of-freedom robot pedal capable of forward, backward, left, and right rotational movements, enabling a variety of gait trajectories.

[0019] However, a limitation of this system lies in the difficulty in controlling the pedals appropriately if the patient, for various reasons, is unable to adapt to the movements of the robotic pedals. For example, if a patient with difficulty walking normally steps onto the robotic pedals, the patient's foot movements during gait training may not be synchronized with each gait cycle, resulting in incoherence.

[0020] Specifically, during mid-stance, when the heel should be lifted, the heel may remain stationary and not lift off the ground. This is because the patient's lower extremities do not follow a normal gait pattern, which can limit the system's ability to effectively provide gait training.

[0021] Therefore, a more flexible and adaptive control algorithm or complementary system design is needed for patients who have difficulty adapting to the movements of the robotic pedals. These alternatives are desirable because they can accommodate the diverse gait characteristics and needs of different patients.

[0022] The present disclosure proposes an effective robot-assisted gait training system and control method that can minimize the intervention of a therapist when bending and extending a joint during gait rehabilitation exercise.

[0023] The present disclosure proposes a robot-assisted gait training system and control method that can enhance the rehabilitation effect by assisting the patient's movement in real time through a wearable robot linked to a main body.

[0024] The present disclosure specifically proposes a robot-assisted gait training system and a control method that can prevent injuries due to disharmony of lower extremity joint movements with respect to the movements of robot pedals by making movements of at least one of the ankle joint, knee joint, and hip joint synchronized with the movements of robot pedals during gait rehabilitation training, thereby promoting safe gait training.

[0025] Robot-assisted walking training system according to the present disclosure:

[0026] A main system comprising a robotic pedal, a gait motion generating unit having a pedal-actuating unit for driving the pedal pedal, and a main controller for operating the pedal-driving unit; and

[0027] A collaborative system is provided, comprising: a joint-actuating unit having one or more joint-actuating motors that are mounted on the lower extremities of a patient and that assist or force movement of the lower extremity joints of the patient in synchronization with the movement of the pedal-actuating unit; and a sub-control unit that controls the movement of the one or more active joint-actuating units in conjunction with the movement of the pedal-actuating unit by controlling the one or more joint-actuating motors.

[0028] Here, the robot pedal is configured to enable 3-degrees of freedom (3-DoF) movement, including two linear movements in the forward-and-backward direction and the up-and-down direction, and one rotational movement centered on a lateral axis that crosses both the forward-and-backward direction and the up-and-down direction.

[0029] The pedal-actuated unit is configured to drive the robot pedal to move along a gait trajectory in a closed loop with the three-degrees of freedom (3-DoF) motion,

[0030] The above joint-actuating unit is configured to assist or force the movement of the patient's joints so that the patient's feet comply with the movement of the robot pedals that move with the three-degrees of freedom (3-DoF) movement, so that the patient's feet are in harmony with the robot pedals.

[0031] According to one or more embodiments,

[0032] The above pedal-operated unit:

[0033] A joint-linkage structure having at least one joint and a plurality of links connected to the at least one joint, or

[0034] The above robot pedal may be any one of a bar-linkage structure that is attached to the end of an operating bar and moves.

[0035] According to one or more embodiments,

[0036] The pedal-actuated unit comprises a joint-link structure that causes three-degrees of freedom movement of the robot pedal along a walking trajectory on the closed loop, wherein

[0037] The above joint-link structure:

[0038] At least one joint;

[0039] At least one operative link connected to at least one joint; and

[0040] It may be provided with at least one drive motor installed in at least one joint and driving the joint.

[0041] According to one or more embodiments,

[0042] The above joint-link structure:

[0043] An operating link having a first driving motor installed at one end for driving the robot pedal;

[0044] A moving station equipped with a second driving motor connected to the other end of the above-described operating link and driving the above-described operating link;

[0045] A guide rail that supports the above moving station so that it can move back and forth in the forward and backward direction a preset distance;

[0046] A transfer plate that is slidably connected to the guide rail, on which the moving station is mounted; and

[0047] It may include an LM unit having a belt coupled to a moving station for linear reciprocating movement of the moving station, a drive pulley and a guide pulley that support the movement of the belt, a third drive motor that provides rotational force to the drive pulley, and a power transmission unit that transmits power from the third drive motor to the drive pulley.

[0048] According to one or more embodiments,

[0049] Pedal-operated unit of the above bar-link structure:

[0050] An operating bar on which the above robot pedal is mounted;

[0051] A closed link that causes the robot pedal to move along the walking trajectory on the closed loop; and

[0052] An operating motor providing rotational force to the above closed link may be provided.

[0053] According to one or more embodiments,

[0054] The joint-drive unit of the above cooperative system:

[0055] a plurality of links located between the joints of the lower limbs; and

[0056] A joint-actuating motor may be provided located at the joint between the above links.

[0057] According to one or more embodiments,

[0058] The above main control unit and the cooperative control unit can be configured to exchange information with each other through wired or wireless communication via a communication unit so as to link the operation of the cooperative system to the operation of the pedal-operated unit.

[0059] According to one or more embodiments,

[0060] The joint-actuating unit of the above cooperative system may include at least one joint-actuating motor among one joint-actuating motor for assisting the movement of the hip joint, one joint-actuating motor for assisting the movement of the patient's knee, and one joint-actuating motor for assisting the movement of the patient's ankle.

[0061] According to one or more embodiments,

[0062] The above joint-actuating unit can force movement of a patient's joint by the joint-actuating motor, and can control the degree of force of the joint by the joint-actuating motor by at least one signal among the angle, resistance torque, and electromyography of the patient's joint from a sensing unit provided in the joint-actuating unit.

[0063] According to one or more embodiments,

[0064] The robot pedal may further include a pressure sensor that detects pressure on the robot pedal and transmits a pressure signal to the main control unit.

[0065] According to one or more embodiments,

[0066] The above cooperative system can force movement of each joint by the joint-actuating motor, and can control the degree of forced movement of the joint by the joint-actuating motor by at least one signal among the angle, resistance torque, and electromyography of the joint from a sensing unit installed in the cooperative system.

[0067] According to one or more embodiments,

[0068] The above sensing unit can be placed at a joint location of the patient or at a location between joints.

[0069] As a control method of a walking training system according to the present disclosure,

[0070] A main system comprising a robot pedal, a walking motion generation unit having a pedal operation unit for driving the pedal, and a main control unit for operating the pedal operation unit; and

[0071] A method for controlling a gait training system using a cooperative system, the cooperative system comprising a joint-actuating unit having one or more joint-actuating motors that assist the movement of the joints of the lower extremities in synchronization with the movement of the pedal-actuating unit, which is mounted on the lower extremities of a patient, and a sub-control unit that controls the movement of the one or more active joint-actuating units in conjunction with the movement of the pedal-actuating unit by controlling the one or more joint-actuating motors,

[0072] A step of controlling the pedal-operating unit to move the robot pedal along a walking trajectory on a closed loop by the main system;

[0073] A step of moving the robot pedal in 3-DoF, including two linear movements in the forward-backward direction and the up-down direction, and one rotational movement centered on a transverse axis crossing both the forward-backward direction and the up-down direction, by the pedal-operated unit; and

[0074] When the movement of the patient's foot is non-adaptive or non-compliant with the movement of the robot pedal that moves with a 3-DoF movement by the above sub-control unit, the step of controlling the joint-actuating unit to force the joint movement of the patient's lower extremity so that the patient's foot is adapted to the robot pedal may be included.

[0075] According to one or more embodiments,

[0076] The system can control the force for forcing joint movement of the patient's lower extremities by the joint-operation motor provided in the joint-operation unit by a signal from a sensing unit that detects status information related to the patient's joint movement by the above sub-control unit.

[0077] According to one or more embodiments,

[0078] The above sensing unit can detect at least one signal among the angle, resistance torque, and electromyography of the corresponding joint of the patient's lower limb.

[0079] According to one or more embodiments,

[0080] The above joint-operating unit has a plurality of links positioned between the patient's joints and interconnected through joints, and the sub-control unit can control the joint movement angle of the patient's lower extremities as an angle between the links on both sides.

[0081] According to one or more embodiments,

[0082] The above robot pedal detects the pedal pressure applied by the patient with a built-in pressure sensor and transmits it to the main control unit.

[0083] The above sub-control unit can receive the pedal pressure and control the joint-operation unit.

[0084] When a patient performs rehabilitation exercises using an end-effector type robot-assisted gait training system, he or she passively moves his or her joints depending on the robot's movements. However, by linking with a wearable robot-type cooperative system, the angle of the patient's lower body joints is controlled through real-time feedback control and the patient's voluntary muscle intervention is induced. The end-effector type robot-assisted gait training system of the present disclosure is linked with a cooperative system that forces the patient's lower body movement in a certain format, thereby assisting the patient's movement through real-time feedback control. This can induce the patient's active movement (muscle movement) by increasing the patient's rehabilitation intensity, and can minimize the therapist's intervention, thereby making rehabilitation efficient and maximizing its effectiveness.

[0085] FIG. 1 illustrates an embodiment of a main system in a wearable robot-assisted walking training system according to the present disclosure.

[0086] FIG. 2 is a side view of the main system in the wearable robot-assisted walking training system according to the present disclosure illustrated in FIG. 1.

[0087] FIG. 3 is a front view of the main system in the wearable robot-assisted walking training system according to the present disclosure illustrated in FIG. 1.

[0088] FIG. 4 is a perspective view showing the structure of a reciprocating LM unit and a pedal-operated unit coupled thereto of a wearable robot-assisted walking training system according to the present disclosure.

[0089] FIG. 5 is a partially enlarged perspective view of the reciprocating LM unit and the pedal-operated unit coupled thereto of the wearable robot-assisted walking training system illustrated in FIG. 4, viewed from another direction.

[0090] FIG. 6 is a schematic perspective view of a walking motion generation unit of a wearable robot-assisted walking training system according to the present disclosure.

[0091] FIG. 7 is a photograph showing the actual three-degree-of-freedom movement of the walking motion generation unit of the wearable robot-assisted walking training system according to the present disclosure in various postures.

[0092] FIG. 8 illustrates step-by-step the movement of the robot pedal along the walking trajectory of the wearable robot-assisted walking training system according to the present disclosure.

[0093] FIG. 9 schematically illustrates the configuration of a pedal-operated unit of a bar-link structure in a wearable robot-assisted walking training system according to the present disclosure.

[0094] Figure 10 illustrates a schematic structure of a cooperative system having a wearable active joint control robot, which is an important element of the exercise system of the present disclosure, and a state in which the robot is worn by a patient.

[0095] FIG. 11 is a block diagram showing the control relationship between the main system of the wearable robot-assisted walking training system according to the present disclosure and the cooperative system having the wearable active joint control robot.

[0096] Figure 12 illustrates a scene in which a patient trains while wearing a robot-type cooperation system in the main system of an exercise system equipped with a wearable active joint control robot, which is an important element of the exercise system of the present disclosure.

[0097] Figure 13 illustrates a normal gait cycle, showing the posture of the feet, knees, and thighs during normal walking.

[0098] Figure 14 illustrates the regulations for foot positions in a walking pattern. And,

[0099] Figure 15 is a graph showing normal changes in joint angles (deg) at the hip, knee, and ankle when extending (ext) and flexing (flex) the joints during one gait cycle.

[0100] Figure 16 is a graph showing the normal changes in joint moments (N-in / kg) at the hip, knee, and ankle when extending and flexing the joints during one gait cycle, and,

[0101] Figure 17 is a graph showing the normal changes in joint power (W / kg) at the hip, knee, and ankle when extending and flexing the joints during one gait cycle.

[0102] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the embodiments of the present invention may be modified in various different forms, and the scope of the present invention should not be construed as being limited by the embodiments described below. It is preferable to interpret that the embodiments of the present invention are provided to more completely explain the present invention to a person having average knowledge in the art. Like reference numerals denote like elements throughout. Furthermore, various elements and areas in the drawings are schematically drawn. Therefore, the present invention is not limited by the relative sizes or intervals drawn in the accompanying drawings.

[0103] While terms such as "first" and "second" may be used to describe various components, these components are not limited by these terms. These terms are used solely to distinguish one component from another. For example, a first component could be referred to as a second component, and vice versa, without departing from the scope of the present invention.

[0104] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the concept of the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the expressions “comprises” or “has” are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, operations, components, parts, or combinations thereof.

[0105] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Furthermore, it is to be understood that commonly used terms, such as those defined in dictionaries, should be interpreted to have a meaning consistent with their meaning within the relevant technical context, and should not be interpreted in an overly formal sense unless explicitly defined herein.

[0106] In some embodiments, where the implementation is otherwise feasible, a particular process sequence may be performed in a different order than described. For example, two processes described in succession may be performed substantially simultaneously, or in a reverse order from the described order.

[0107] Hereinafter, a wearable robot-assisted walking training system and a control method thereof according to one or more embodiments are described.

[0108] FIG. 1 illustrates one embodiment of a main system (100) in a wearable robot-assisted walking training system according to the present disclosure.

[0109] And, FIG. 2 is a side view of FIG. 1 and FIG. 3 is a front view of the wearable robot-assisted walking training system according to the present disclosure.

[0110] The wearable robot-assisted walking training system according to the present disclosure has the main system (100) and a cooperative system (200) in the form of a wearable active joint control robot as illustrated in FIG. 6 described below. The main system (100) will be described first below.

[0111] Referring to FIGS. 1 and 2, the main system (100) is a type of robot that provides walking training to a patient, and provides a walking motion generation unit (105) having two left and right end-effect type robot pedals (105a) on which the patient steps with both feet.

[0112] The above main system (100) is provided with a first base (101a) and a second base (101b) on the left and right sides that are placed on the floor and support the entire structure, and the walking motion generation unit (105) is located between the first and second bases (101a, 101b) on the left and right sides.

[0113] The above walking motion generating unit (105) includes first and second pedal-actuating units (105L, 105R) on the left and right sides, to which the left and right robot pedals (105a) are respectively coupled. Each of these first pedal-operated units (105L) and second pedal-operated units (105R) comprises a robot pedal (105a), a first operating link (105b) to which the robot pedal (105a) is operably connected via a first driving motor (105d), and the first operating link (105b) has a first driving motor (105d) that rotates the robot pedal (105a) within a predetermined angular range set by an individual training plan, and is connected to a second driving motor (105c) provided on each of the left and right bases (101a, 101b) and rotates by the second driving motor (105c). Linear motion

[0114] The second driving motor (105c) that rotates the above-described operating link (105b) within a preset angle range is coupled to a moving stage (108s) of a reciprocating linear motion unit (108, see FIGS. 4a and 4b) described later, and can perform linear reciprocating motion along the corresponding base (101a, 102a). More detailed information follows in the description of FIGS. 4a and 4b.

[0115] The robot pedal (105a) of each of the first and second pedal-operating units (105L, 105R) on the left and right sides, which are arranged between the left and right bases (101a, 101b), moves in harmony with each other in response to the movement trajectories of the left and right feet during walking, for example, with the soles of the feet stably resting on the upper surfaces of the pedals, and in some cases, may intentionally move in a disharmonious manner.

[0116] The above robot pedal (105a) is moved by the system operating device described below to enable the patient to perform a walking movement suitable for the patient. The patient can stand on it and walk in accordance with the movement of the robot pedal. An ankle band that can be installed here secures the patient's foot to the robot pedal appropriately, either loosely or tightly, to a certain extent that the patient's foot can move within a certain range.

[0117] The movement of the two robot pedals (105a) is controlled by the system operating device to accommodate an abnormal gait pattern while training the gait pattern to be closer to a normal gait pattern for the purpose of gait training of the patient.

[0118] In addition to the operating elements as described above, as illustrated in FIGS. 1 to 3, an assembly is provided in which a saddle (104) and a safety bar (106) thereon or a fence part (107) including the same for supporting the chest, etc. are combined into one, in front of the walking motion generating part (105). This assembly is installed with respect to a lifting unit (102) via an up-and-down frame (103). The lifting unit (102) is an assembly raising / lowering device that adjusts the height of the assembly to match the patient's physical condition. A system status display part (109) facing the patient is provided at the top of this lifting unit (102).

[0119] At the front of the main system (100) viewed by the patient, a lifting or fixed support column (113a) is installed, and a system monitor (113) that displays the operating status of the entire system is connected thereto.

[0120] Figures 4 and 5 illustrate the structure and coupling relationship of the reciprocating LM unit (108) described above and the pedal-operated units (105L, 105R) coupled thereto.

[0121] First, looking at the LM unit (108), two guide rails (108r) that are parallel to each other in the longitudinal direction are installed on the base frame (108f), and a transfer plate (108c) is coupled to these two guide rails (108r) so that linear movement is possible via an LM guide (108g), and a moving stage (108s) equipped with a second drive motor (105c) that drives an operating link (105b) is integrally coupled to the transfer plate (108c) so that it moves in linear motion (LM1) simultaneously with the transfer plate (108c).

[0122] The moving stage (108s) is an endless track type belt, for example, a transfer belt (108b), which is installed in the longitudinal direction of the base frame (108f) and in the same direction as the guide rail (108r), and for example, the transfer belt is engaged with a driven pulley (108dp) and a guide pulley (108gp), so that movement on an endless track is possible therebetween. The driven pulley (108dp) and the guide pulley (108gp) are arranged in the movement direction of the moving stage (108s), and thereby the moving stage (108s) or the transfer plate (108c) can be coupled to a part of the transfer belt (108b) whose movement is guided.

[0123] A third drive motor (108m) is installed on one side (outer side in the drawing) of the base frame (108f), and the rotational power of the third drive motor (108m) is transmitted to the driven pulley (108p1) through a powertrain unit (107t). In the present embodiment, the driven pulley (108p1) is coaxially and integrally connected with a planetary pulley (108p3) that receives power from the drive pulley (108p4) of the third drive motor (108m) through a drive belt (108b2) as an element of the powertrain unit (107t).

[0124] In this embodiment, the power transmission structure uses a pulley and a belt whose movement is guided by the pulley, but the technical scope of the present disclosure is not limited by this specific power transmission structure.

[0125] Figure 6 is a schematic perspective view of a walking motion generation unit (105).

[0126] As illustrated in Fig. 6, the movement of the robot pedal (105a) in three directions can occur with three degrees of freedom. This movement occurs as a composite of the first rotational motion, the second rotational motion, and the first linear motion.

[0127] In these three degrees of freedom movements, the first rotational movement (RM1) is a rotational movement of the robot pedal (105a) with respect to the operating link (105b), the second rotational movement (RM2) is a rotational movement of the robot pedal (105a) with respect to the operating link (105d) performed by the second driving motor (105d), and the first linear movement (LM1) is a linear movement of the second driving motor (105c) by the moving stage (108s, see FIG. 5) of the LM unit (108).

[0128] And, according to an appropriate combination of the first rotational motion (RM1) and the second rotational motion (RM2), a second linear motion (LM2) in the up-and-down direction of the robot pedal is generated.

[0129] Therefore, according to the two rotational movements and two linear movements described above, the robot pedals (105) move with one rotational movement and two linear movements.

[0130] As a result, the robot pedal (105a) moves along a closed-loop movement trajectory by a compound motion of one rotational motion and two linear motions, and at this time, the angle of the robot pedal (105a, 105b) changes, forcing the patient's ankle angle.

[0131] These complex exercises force the patient's feet to move, thereby inducing normal walking in the patient by applying all joints of the patient's lower extremities, namely the hip joint, knee joint and ankle joint, according to the position and posture of the feet.

[0132] Meanwhile, the robot pedal (105a) is coupled to the operating link (105b) to enable a rotational movement (RM2) of a predetermined angle with respect to the operating link (105b) via the first driving motor (105d), and a band (not shown) capable of binding the patient's foot or ankle or a clamp or cleat structure for fixing the shoe and the robot pedal may be installed or provided.

[0133] The composite movements in the up-down, forward-backward, and backward directions of each of the two robot pedals (105a, 105a) of the above-mentioned walking motion generating unit (105) are performed independently, but when walking, they move away from each other or come closer to each other and then intersect each other in response to the movements of the left and right feet. For such composite movements, a structure other than the specific structure described above can be applied. For example, a linear motion driving device for controlling a linear reciprocating motion of the operating link or the entire walking motion generating unit (105) equipped therewith, and a rotary or rotational motion driving device for controlling a rotational motion of the operating link (105b) can be provided in various forms.

[0134] The walking motion generation unit (105) described above has been described very specifically as having a structure for driving a robot pedal (105a) including an operating link (105b), first and second driving motors (105c, 105d), and an LM unit (108), but it should be understood that the technical scope of the present invention is not limited to the specific structure of the walking motion generation unit (105).

[0135] FIG. 7 is a photograph showing various positions (footrest positions) and postures (changes in footrest angle) along actual three-degree-of-freedom movements implemented in the walking motion generation unit of the wearable robot-assisted walking training system according to the present disclosure.

[0136] As illustrated in Figure 7, the robotic pedal on which the patient stands performs three degrees of freedom of motion, including forward-and-backward, up-and-down, and rotational movements about a lateral axis orthogonal to these two directions. This three-degree-of-freedom motion allows the patient's foot to move forward-and-backward and up-and-down, while simultaneously inducing rotation of the ankle joint.

[0137] That is, the robot pedal is capable of three degrees of freedom (3-DOF) movement consisting of two linear movements and one rotational movement. Here, the two linear movements include movements in the forward-backward direction and the up-down direction, respectively, and one rotational movement is performed around a transverse axis that crosses both the forward-backward direction and the up-down direction.

[0138] These three degrees of freedom movements are designed to replicate the natural movements of the patient's ankle and lower extremity joints, maximizing the effectiveness of gait training.

[0139] FIG. 8 illustrates changes in position and posture during the process of moving the robot pedal along the walking trajectory (105gt) in the wearable robot-assisted walking training system according to the present disclosure.

[0140] As illustrated in Fig. 8, the robot pedal (105a) moves along the walking trajectory (105gt), and has a position and posture (angle) that continuously changes along the walking trajectory (105gt) while performing two linear movements (LM1, LM2) and two rotational movements (RM1, RM2). The progress trajectory of the robot pedal and the angle that changes while moving along the trajectory are training gait trajectories presented for patient training, and the ultimate goal of gait training is to converge them to the gait trajectory of a normal walker.

[0141] According to another embodiment of the present disclosure, a walking motion generation unit for driving a three-degree-of-freedom end-effect robot pedal directly related to the patient's walking training may be applied to a joint-linkage structure in which the robot pedal has a plurality of joints and links at the end thereof that are capable of linear or rotational movement, or a bar-linkage structure in which the robot pedal is moved by being attached to the end of an operating bar. In addition, for example, a guide rail-assisted bar-linkage structure in which a rail for guiding the movement of the robot pedal is added to a bar-linkage structure in which the robot pedal is moved by being attached to the end of an operating bar may be adopted, and this may also be considered to fall within the scope of the present invention.

[0142] Figure 9 schematically and conceptually simplifies the schematic configuration of a three-degree-of-freedom end-effect type gait training system by a gait motion generation unit of a bar-link structure.

[0143] Referring to FIG. 9, the walking motion generation unit has two bar-link structures (302) on the left and right, and the drawing shows one bar-link structure (302). Each bar-link structure (302) has two long operation bars, namely a first operation bar (302c) and a second operation bar (302d), which are directly operated by an operation motor (307).

[0144] In the walking motion generating section of the bar-link structure, one end (left side in the drawing) of the first operating bar (302c) and the second operating bar (302d), which are components of the closed link, is configured to be directly operated by an operating motor (307). Here, one end of the first operating bar (302c) is rotatably connected to a rotating wheel (306a) or a rotating arm (306) that is rotated by the operating motor (307), and the second operating bar (302d) slides in contact with a rotating cam (305) that is rotated by the operating motor (307) and rotates in the up-and-down direction according to a change in the contact position with the rotating cam (305).

[0145] A short third operating rod or operating plate (302 a) on which a footrest or robot pedal (301) is installed is rotatably interconnected at both ends of the first operating bar (302c) and the second operating bar (302d) (right side in the drawing).

[0146] According to this structure, the rotary wheel (306a) and the rotary cam (305) are rotated by the operating motor (307), and the first operating bar and the second operating bar (302c, 302d) move in response to the movement of the rotary wheel and the movement of the cam, respectively, and accordingly, the operating plate (302a) at the tip where the robot pedal (301) is located moves back and forth left and right and slightly rises and falls up and down, so that the movement of the robot pedal (301) is formed along the trajectory as indicated by reference number “304”, and thus the patient (1) steps on it and performs walking training.

[0147] The pedal-operated unit of the bar-link structure illustrated in Fig. 9 has a plate provided with a pedal, a closed link structure by a first operating bar and a second operating bar, and a drive motor that operates it.

[0148] The pedal-operated unit of the bar-link structure illustrated in Fig. 9 merely illustrates the basic outline of the bar-link structure, which can be modified or improved in various forms, and the technical scope of the present invention is not limited by this specific structure.

[0149] Gait training using robotic pedals, as described above, is suitable for patients who can adapt to the robotic pedals to some degree. However, for patients who still have difficulty stepping onto the robotic pedals for training, for example, those with lower extremity movement that does not reach a certain level, a cooperative device that forces the lower extremities to adapt, adapt, or coordinate with the robotic pedal movements for gait training is required. This disclosure proposes such a device.

[0150] The cooperative device is applied when the patient's lower extremities are weak or unstable, or when the patient's foot movements do not follow the movements of the robotic pedals during gait training by fixing the foot to them. That is, when the patient's foot movements are non-adaptive or non-compliant with the movements of the robotic pedals, the device forces the movement of the lower extremity joints so that the patient's foot adapts or harmonizes with the robotic pedals.

[0151] For example, forced training is performed on a patient who cannot move his lower extremities properly, and through this forced training, he can forcefully place his feet on the pedals when he was unable to do so before. This cooperative system appropriately forces the movement of the joints of the lower extremities with controlled force, so that the movement of the lower extremities, especially the soles of the feet, are as compatible as possible with the robotic pedals, and is a cooperative system for gait training that forces the movement of the lower extremity joints, not for gait training itself. FIG. 10 illustrates a schematic structure of a cooperative system (200) equipped with a wearable active joint control robot, which is an important element of the exercise system of the present disclosure, and illustrates a state in which a patient (1) wears it.

[0152] The cooperative system (200) according to the present disclosure can be designed and manufactured to enable forced training of both legs by the patient's feet in response to the movement of the robot pedals during gait training, as exemplarily illustrated in FIG. 10, but according to another embodiment, it can be made to correspond to only one leg.

[0153] A collaborative system (200) having an active joint control robot structure of which only half is illustrated in FIG. 10 has a wearable band (201) that is worn or fixed to a patient's body, for example, the waist, and a first joint-drive unit (200L) on the left and a second joint-drive unit (200R) on the right, corresponding to the left and right legs underneath. Each of the two joint-drive units (200L, 200R) is provided underneath the wearable band (201) and has a number of links (three in the drawing) that are connected from the waist to the feet, namely, a first link (205) between the waist belt 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 optionally a foot fixing unit (208) as needed, which may be added or reduced depending on needs and design conditions. Here, the foot fixing part (208) can be designed so that the pressure of the sole of the foot is transmitted to the robot pedal and only the angle control of the ankle joint with respect to the third link (207) is possible.

[0154] Between each of the above links, an active joint control element for active joint control, i.e., a joint-driving motor (202, 203, 204), is provided. These joint-driving motors (202, 203, 204), i.e., actuators, may be provided in various types of actuators such as a rotary motor or a reciprocating fluid cylinder, and may include a sensing unit (212, 213, 214) for measuring joint angles, resistance torques, electromyograms, etc. The joint-driving motors (202, 203, 204) actively control, for example, the angle or torque of a lower link with respect to an upper link, or the angle and torque between the upper and lower links. This control is flexible and forces the joints therebetween to be maintained within a certain range. These active joint control elements are controlled by the control unit of the main system (100), and their operation is synchronized to the movement of the robot pedals, for example, the gait cycle pattern, and may be intentionally controlled not to be synchronized depending on the training method.

[0155] This cooperative system (200) assists walking training using a three-degree-of-freedom robot pedal, so that even patients with weak lower limbs can perform walking training using the robot pedal.

[0156] Figure 11 is a block diagram showing the control relationship between the main system (100) and the cooperative system (200) equipped with the wearable active joint control robot.

[0157] As shown, the main system (100) and the cooperative system (200) are connected through a communication unit (198) so that a command (instruct) from the main system (100) is transmitted to the cooperative system (200) and the result is returned to the main system (100).

[0158] The above communication unit (198) can be applied to various short-range communication methods, for example, Bluetooth can be applied. The illustrated communication unit (198) is provided as a representative communication unit as an element of symbolic meaning, and the main control unit and the cooperative control unit can be connected through this communication unit.

[0159] The first sensing unit (212), the second sensing unit (213), and the third sensing unit (214) measure the patient's joint angle, joint resistance torque, electromyography, etc., and transmit the measured values ​​to the main control unit through the communication unit.

[0160] The above first, second, and third sensing units (212, 213, 214) may be provided for each of the joint-actuating motors (202, 203, 204), and according to another embodiment, may be provided between each of the joint-actuating motors.

[0161] The above-described cooperative control unit (210) controls the joint-actuating motors (driving units, 202, 203, 204) of the joint-actuating units (200L, 200R) that force the angle of the lower body joints of the patient (1) as described above. The driving units control a first joint-actuating motor (202) for forcing the hip joint, a second joint-actuating motor (203) for controlling the knee joint, and a third joint-actuating motor (204) for controlling the ankle joint, and these joint-actuating motors, i.e., actuators, can be increased or decreased as needed and designed.

[0162] FIG. 12 illustrates a scene in which a patient (1) is trained while wearing a robot-type cooperation system (200) in the main system (100) according to the present disclosure. As illustrated in FIG. 9, for example, in the case of a severely ill patient, the patient (1) can perform gait training while wearing the cooperation system (200), i.e., the wearable robot, and holding the safety bar (106) without being on the saddle (104). Depending on the condition of the patient (1), for example, in the case of a mildly ill patient, the saddle (104) can be folded, and thus the patient (1) can perform gait training without relying on the saddle (104), and this can follow a training plan planned according to the condition of the patient.

[0163] The above robot pedal (105a) is operated by the system operating device to force the patient to walk regardless of the patient's will. At this time, pressure sensors, etc. are installed on the saddle (104) and the robot pedal (105a) to detect the load applied to the saddle (104) and the load applied to the robot pedal in the walking training state. In particular, a plurality of pressure sensors are provided before and after the robot pedal to detect the local pressure applied to the robot pedal, thereby detecting the degree of pressure applied to the sole of the foot or whether it is in contact with the robot pedal.

[0164] The above robot pedal detects pedal pressure applied by a patient with a built-in pressure sensor and transmits it to the main control unit, and the sub-control unit can receive the pedal pressure and control the joint-operation unit.

[0165] In this process, the cooperative system (200) forces the movement of one or more joints with an appropriately controlled force using the drive units of the cooperative system (200) along with the patient's training progress by the main system (100), and as one of the results, the degree of force of the corresponding joint can be controlled by at least one signal from the sensing unit among the angle, resistance torque, and electromyography of at least one joint.

[0166] Figure 13 illustrates a normal gait cycle that is referenced for gait training of a patient, showing the posture of the foot, knee, and thigh during normal gait, and Figure 14 illustrates the regulations for each position in the gait pattern.

[0167] Referring to Figure 13, in one gait cycle, the stance phase is the section where the foot touches the ground, and the swing phase is the section where the foot is lifted off the ground.

[0168] Within each gait cycle, there are three tasks:

[0169] 1. Weight Acceptance

[0170] This period has two parts: Initial contact (when the foot first touches the ground) and Loading response (when the sole of the foot touches the ground).

[0171] 2. Single Limb Support

[0172] This period is the mid-stance where the sole of the foot touches the ground, the foot of the opposite leg leaves the ground, and the heel rises and the opposite leg swings.

[0173] 3. Limb Advancement

[0174] This period is the period when the other foot is planted, and includes the free swing, where the toes of the front foot lift off the ground as the back foot leaves the ground; the mid swing, where the foot that was on the ground earlier begins to lift off while the feet are together; and the terminal swing, where the heel of the front foot begins to touch the ground as the back foot pushes off the ground.

[0175] The above gait pattern is a normal gait pattern, and patients are trained to acquire this normal gait pattern. However, in the case of patients who have difficulty walking normally, the patient's feet may be out of sync during gait training. For example, during the mid-stance cycle, the heel of the rear foot may not lift off when it should, but remain on the floor. This is because the patient's body does not follow the normal gait pattern. The robotic cooperative system (200) of the present disclosure can forcibly bend the knee joint or ankle joint with a controlled force during this period to match the patient's gait pattern, thereby lifting the heel of the rear foot off the floor. All of these forced joint movements can be performed within the cycle, and through this, the patient undergoing gait training can be forced to have a similar, if not normal, gait pattern despite their physical limitations.

[0176] Figure 14 illustrates the rules for foot position in a gait pattern, and Figures 15, 16, and 17 are graphs showing normal changes in joint angles (deg), joint moments (N-in / kg), and joint powers (W / kg) at the hip, knee, and ankle when extending and flexing the joints during one gait cycle. In the graphs of Figures 15, 16, and 17, IC represents heel initial contact, OT represents opposite toe off in, HR represents heel rise, and OI represents opposite initial contact.

[0177] Referring to Figures 14 to 17, the normal state of foot position in the walking pattern is as follows.

[0178] a. Initial contact (heel strike)

[0179] 1. The angle of the hip joint is approximately 30 degrees (flex).

[0180] B. Loading Response

[0181] 1. Hip joint: around 25 degrees (flex)

[0182] 2. Knee joint: about 10 degrees (flex)

[0183] 3. Ankle joint: approximately 10 degrees (plantar flexion)

[0184] D. Mid stance

[0185] 1. Hip joint: 25 degrees (flex) ~ 10 degrees (ext)

[0186] 2. Knees: Peak (flex) ~ approximately 0 degrees

[0187] 3. Ankle: changing to dorsiflexion

[0188] A. Heel Rise, Heel Off

[0189] 1. Hip joint: -10 degrees (continues to extension.)

[0190] 2. Knee: Extension peak

[0191] 3. Ankle: 0 degrees

[0192] Toe Off, Terminal Contact

[0193] 1. Hip joint: -20 to 20 degrees (Continues to flex)

[0194] 2. Knee joint: 20 degrees (Continues to flex)

[0195] 3. Ankle joint: Plantar flexion peak

[0196] Bar. Initial Swing (Initial Swing~Mid Swing)

[0197] 1. Hip joint: 20 to 30 degrees (continues to flex)

[0198] 2. Knee: 60 degrees (flex peak) ~ 30 degrees

[0199] 3. Ankle: 10 to 0 degrees

[0200] Based on the normal state of the foot as described above, the training system according to the present disclosure performs gait training on the patient using a robot pedal, aiming for the normal range as described above.

[0201] In an embodiment of the present disclosure, a wearable robot-type cooperative system is used in synchronization with the operation of the walking motion generation unit of the main system to forcibly control the angles of the hip joint, knee joint, ankle joint, etc., for example, by considering the normal bending and extension angles, the patient's joints are forced to flex and extend, thereby preventing the so-called back-knee phenomenon and enhancing the effect of rehabilitation. In addition, by forcibly controlling the angle of the patient's abnormal knee to a normal range, the phenomenon of the heel coming off the ground early in the midstance can be prevented.

[0202] Here, the wearable collaborative system conceptually illustrated in FIG. 10 can be implemented in various forms, and can be implemented in any form that can force at least one of the patient's lower body joints in compliance with the control of the main system, and such actual implementations are naturally within the scope of the present invention as long as they have the above-described control structure. In addition, as described above, the walking motion generation unit for driving the end-effect type robot pedal may have a structure in which the robot pedal includes an operating link, first and second driving motors, and an LM unit, as described above, and according to another embodiment, the walking motion generation unit may adopt a bar-connection structure in which the robot pedal is attached to the end of an operating bar and moves, or a rail-supported bar-connection structure in which a rail for guiding the movement of the robot pedal is added to the bar-connection structure, and this is also naturally within the scope of the present invention.

[0203] While exemplary embodiments of the present invention have been described in detail above, those skilled in the art will appreciate that various modifications and variations may be made to the invention without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, modifications to future embodiments of the present invention will not depart from the scope of the invention.

Claims

1. A main system comprising a robotic pedal, a gait motion generating unit having a pedal-actuating unit for driving the pedal-actuating unit, and a main controller for operating the pedal-driving unit; and A collaborative system comprising a joint-actuating unit having one or more joint-actuating motors that assist the movement of joints of the lower extremities in synchronization with the movement of the pedal-actuating unit, which is mounted on the lower extremities of a patient, and a sub-controller that controls the movement of the one or more active joint-actuating units in conjunction with the movement of the pedal-actuating unit by controlling the one or more joint-actuating motors, wherein, The above robot pedal is configured to enable 3-degrees of freedom (3-DoF) movement, including two linear movements in the forward-and-backward direction and the up-and-down direction, and one rotational movement centered on a lateral axis that crosses both the forward-and-backward direction and the up-and-down direction. The pedal-actuated unit is configured to drive the robot pedal to move along a gait trajectory in a closed loop with the 3-DoF motion, A robot-assisted walking training system, wherein the above joint-actuating unit is configured to force the movement of the joint of the patient's foot to adapt to the robot pedal when the movement of the patient's foot is non-adaptive or non-compliant with the movement of the robot pedal that moves with the 3-DoF movement.

2. In paragraph 1, The above pedal-operated unit: A joint-linkage structure having at least one joint and a plurality of links connected to the at least one joint, or A robot-assisted walking training system, characterized in that the robot pedal is one of bar-linkage structures that is attached to the end of an operating bar and moves.

3. In paragraph 1, The pedal-actuated unit comprises a joint-link structure that causes three-degrees of freedom movement of the robot pedal along a walking trajectory on the closed loop, wherein The above joint-link structure: At least one joint; At least one operative link connected to at least one joint; and A robot-assisted walking training system comprising at least one drive motor installed in at least one joint and driving the joint.

4. In paragraph 3, The above joint-link structure: An operating link having a first driving motor installed at one end for driving the robot pedal; A moving station equipped with a second driving motor connected to the other end of the above-described operating link and driving the above-described operating link; A guide rail that supports the above moving station so that it can move back and forth in the forward and backward direction a preset distance; A transfer plate that is slidably connected to the guide rail, on which the moving station is mounted; and A robot-assisted walking training system comprising: an LM unit having a belt coupled to a moving station for linear reciprocating movement of the moving station, a drive pulley and a guide pulley that support the movement of the belt, a third drive motor that provides rotational force to the drive pulley, and a power transmission unit that transmits power from the third drive motor to the drive pulley.

5. In paragraph 3, Pedal-operated unit of the above bar-link structure: An operating bar on which the above robot pedal is mounted; A closed link that causes the robot pedal to move along the walking trajectory on the closed loop; and A robot-assisted walking training system comprising: an actuating motor that provides rotational force to the closed link.

6. In paragraph 1, The joint-drive unit of the above cooperative system: a plurality of links located between the joints of the lower limbs; and A robot-assisted walking training system having a structure of a multi-joint robot having a joint-actuating motor located at a joint between the above links.

7. In any one of paragraphs 1 to 6, A robot-assisted walking training system, wherein the main control unit and the cooperative control unit exchange information with each other through wired or wireless communication via a communication unit, thereby linking the operation of the cooperative system to the operation of the pedal-operated unit.

8. In paragraph 6, A robot-assisted walking training system, wherein the joint-actuating unit of the above-mentioned cooperative system comprises at least one joint-actuating motor among one joint-actuating motor for assisting the movement of the hip joint, one joint-actuating motor for assisting the movement of the patient's knee, and one joint-actuating motor for assisting the movement of the patient's ankle.

9. In paragraph 7, A robot-assisted walking training system in which the joint-actuating unit forces movement of the patient's joint by the joint-actuating motor and controls the degree of force of the joint by the joint-actuating motor by at least one signal among the angle, resistance torque, and electromyography of the patient's joint from a sensing unit provided in the joint-actuating unit.

10. In paragraph 9, A robot-assisted walking training system further comprising a pressure sensor for detecting pressure on the robot pedal and transmitting a pressure signal to the main control unit.

11. In any one of paragraphs 1 to 6, A robot-assisted walking training system in which the above cooperative system forces the movement of each joint by the joint-actuating motor and controls the degree of forced movement of the joint by the joint-actuating motor by at least one signal among the angle, resistance torque, and electromyography of the joint from a sensing unit installed in the cooperative system.

12. In paragraph 10, A robot-assisted walking training system, wherein the sensing unit is positioned at the patient's joint location or at a location between joints.

13. A main system comprising a robot pedal, a walking motion generation unit having a pedal operation unit for driving the pedal pedal, and a main control unit for operating the pedal operation unit; and A method for controlling a gait training system using a cooperative system, the cooperative system comprising a joint-actuating unit having one or more joint-actuating motors that assist the movement of the joints of the lower extremities in synchronization with the movement of the pedal-actuating unit, which is mounted on the lower extremities of a patient, and a sub-control unit that controls the movement of the one or more active joint-actuating units in conjunction with the movement of the pedal-actuating unit by controlling the one or more joint-actuating motors, A step of controlling the pedal-operating unit to move the robot pedal along a walking trajectory on a closed loop by the main system; A step of moving the robot pedal in 3-DoF, including two linear movements in the forward-backward direction and the up-down direction, and one rotational movement centered on a transverse axis crossing both the forward-backward direction and the up-down direction, by the pedal-operated unit; and A method for providing robot-assisted walking training, comprising: a step of forcing joint movement of the patient's lower extremities by controlling the joint-actuating unit to adapt the patient's feet to the robot pedals when the movement of the patient's feet is non-adaptive or non-compliant with the movement of the robot pedals that are moved by the 3-DoF movement by the sub-control unit; 14. In paragraph 13, A control method of a robot-assisted walking training system, wherein the system controls a force for forcing joint movement of a patient's lower extremities by a joint-operation motor provided in the joint-operation unit by a signal from a sensing unit that detects status information related to the patient's joint movement by the sub-control unit.

15. In paragraph 14, A control method for a robot-assisted walking training system, wherein the sensing unit detects at least one signal among the angle, resistance torque, and electromyography of the corresponding joint of the patient's lower limb.

16. In paragraph 13, A control method for a robot-assisted walking training system, wherein the above joint-operating unit has a structure of a multi-joint robot in which a plurality of links positioned between the patient's joints are interconnected through joints, and the sub-control unit controls the joint movement angle of the patient's lower extremities as an angle between the links on both sides.

17. In paragraph 14, A control method for a robot-assisted walking training system, wherein the above joint-operating unit has a structure of a multi-joint robot in which a plurality of links positioned between the patient's joints are interconnected through joints, and the sub-control unit controls the joint movement angle of the patient's lower extremities as an angle between the links on both sides.

18. In paragraph 15, A control method for a robot-assisted walking training system, wherein the above joint-operating unit has a structure of a multi-joint robot in which a plurality of links positioned between the patient's joints are interconnected through joints, and the sub-control unit controls the joint movement angle of the patient's lower extremities as an angle between the links on both sides.

19. In paragraph 13, The above robot pedal detects the pedal pressure applied by the patient with a built-in pressure sensor and transmits it to the main control unit. A control method for a robot-assisted walking training system, wherein the sub-control unit receives the pedal pressure and controls the joint-actuating unit.

20. In paragraph 15, The above robot pedal detects the pedal pressure applied by the patient with a built-in pressure sensor and transmits it to the main control unit. A control method for a robot-assisted walking training system, wherein the sub-control unit receives the pedal pressure and controls the joint-actuating unit.

Images