KR102217337B1 - Elastomer Gear Unit And Elastic Actuator Having The Same - Google Patents

Abstract

The present invention relates to an elastic gear unit and a joint actuator having the same. More particularly, the present invention relates to an elastic gear unit and a joint actuator having the same, which reduces noise and vibration when driving a drive motor, has improved durability compared to the case where a non-metallic elastic member is inserted and can secure sufficient elastic force and elastic displacement, and can be configured in the form of a single gear to simplify the structure of the joint actuator.

Description

Elastomer Gear Unit And Elastic Actuator Having The Same}

The present invention relates to an elastic gear unit and a joint actuator having the same. In more detail, the present invention reduces noise and vibration when driving the driving motor, improves durability and secures sufficient elastic force and elastic displacement than when a member made of a non-metallic elastic material is inserted, and consists of a single gear. The present invention relates to an elastic gear unit capable of simplifying the structure of the joint actuator and a joint actuator having the same.

Recently, the development of wearable robots for the disabled, patients, or the elderly who have physical abilities that are impossible to daily life, or industrial or military wearable robots to reinforce physical strength or physical abilities are in progress.

In the case of wearable robots for the handicapped, patients, or the elderly, it can be classified into wearable robots for completely paralyzed persons with disabilities and wearable robots for the elderly or partially paralyzed patients or handicapped according to their physical ability and the size or role of required assistance. .

In the former case, since the user has no physical ability, the motion intention for the movement of the user's lower limbs is not of great significance as a control variable of the robot, so the wearable robot can walk accurately instead of the user's lower limb movement with sufficient force. You can do it.

Therefore, in the case of the former wearable robot, the required driving force is large and accordingly, the driving device, the battery, and the skeleton structure are large in many cases.

However, in the case of the latter wearable robot, the size and weight of the wearable robot are minimized, and the key is to provide accurate assistance according to the user's motion intention. I can.

In the case of the latter wearable robot, if the robot wearer's movement is possible to a certain extent, if the weight of the robot or the mechanical resistance of the joint drive device is large, the wearer may feel quite cramped and uncomfortable. A structured wearable robot is required. Furthermore, in recent years, in the case of providing assistance from a robot that is different from the user's movement or intention, it may cause discomfort or injury to the user, and while allowing the user's movement, it is intended to accurately provide assistance by understanding the user's motion intention. Research is ongoing.

In addition, when the joint actuator is applied to a wearable robot for patients with partial paralysis of the lower body or for the elderly, it requires a technology to minimize the weight or volume of the robot while increasing the operating time of the wearable robot so that it can be used in daily life. do.

To this end, in order to minimize the weight and volume of the joint actuator for providing the assisting force of each joint, the structure of the driving device, which is the main component of the wearable robot, should be simplified, and lightweight and compact should be premised.

In addition, when a joint driving device made of a metal material is driven, noise and vibration may be large, and minimizing the noise and vibration of the joint driving device is expected to be helpful in the spread and use of the wearable robot.

In particular, since these wearable robots are applicable not only to adult patients or persons with disabilities, but also to pediatric patients or disabled persons with weak muscle strength, mechanical resistance is reduced, the structure is simplified to reduce weight, and noise and vibration are minimized to minimize rejection to the robot. There is a greater demand for a driving device capable of grasping the robot wearer's motion intention.

In the present invention, noise and vibration during driving of a driving motor are reduced, durability is improved, sufficient elastic force and elastic displacement can be secured, compared to the case of inserting a member made of a non-metallic elastic material. It is an object to be solved to provide an elastic gear unit capable of simplifying the structure of the actuator and a joint actuator having the same.

In order to solve the above problem, the present invention is a gear member in the form of an arc formed with a gear mountain on the outer peripheral surface; A driving member having a mounting portion mounted inside the gear member and a driving portion disposed coaxially with the mounting portion; It is possible to provide an elastic gear unit including a plurality of elastic members mounted between the gear member and the mounting portion of the driving member to allow relative rotation of the gear member or the driving member while providing elastic restoring force.

Here, the gear member has a plurality of support portions for supporting one end of the elastic member protruding inwardly on the inner circumferential surface, and the mounting portion of the driving member extends in the direction of the inner circumferential surface of the gear member to be supported on the support portion of the gear member. A plurality of support arms for supporting the other end of each elastic member may be provided.

In addition, three support portions of the gear member are provided at 90 degree intervals, and two support arms of the driving member are provided at 90 degree intervals, each of which is disposed between mutually adjacent support portions of the gear member, and four elastic members May be disposed between the support portion of the gear member and the support arm of the drive member.

Further, a guide groove for limiting the rotation range of the support arm of the driving member may be formed on the inner circumferential surface of the gear member.

In addition, the plurality of elastic members may be composed of a coil spring, in this case, so that at least some of the plurality of elastic members are disposed via a support part of the gear member or a support arm of the driving member, A part of the coil may be configured in an unfolded state.

On the other hand, the present invention is a drive motor; A driving gear mounted on the rotation shaft of the driving motor; A first reduction gear connected to the driving gear and having a first large gear portion having a larger diameter than the driving gear and a first small gear portion having a diameter smaller than that of the first large gear portion; A second reduction gear connected to a first small gear portion of the first reduction gear and having a second large gear portion having a larger diameter than the first small gear portion and a second small gear portion having a diameter smaller than that of the second large gear portion; The elastic gear unit to which an external gear member is connected to a second small gear portion of the second reduction gear; It is fastened to the driving member of the driving member of the elastic gear unit, the output member coupled to the thigh member or the lower leg member of the wearable robot; may provide a joint actuator comprising a.

Here, a pair of encoders for measuring the angle, speed, or acceleration of the rotation shaft of the elastic gear unit and the rotation shaft of the drive motor; And a controller for controlling the driving motor according to information sensed by the encoder or a predetermined walking program.

In this case, the control unit drives the driving motor according to the walking mode, the driving force of the driving motor is transmitted to the output member through the elastic gear unit, and when the wearer is walking, the output member of each joint actuator is It is possible to assist the wearer's walking by assisting the rotational drive of the thigh member or the lower leg member.

In addition, when the motor constituting the joint actuator is stopped, the output member constituting the joint actuator rotates and the rotation of the elastic gear unit or the output member is detected by an encoder provided in the elastic gear unit. The control unit may drive the drive motor to provide an auxiliary force in the rotational direction of the elastic gear unit or the output member.

In addition, the outer diameter of the gear member constituting the elastic gear unit may be larger than the outer diameter of the large gear portion of the first reduction gear or the second reduction gear.

According to the elastic gear unit and the joint actuator having the same according to the present invention, when the joint actuator is driven by arranging an elastic member in the form of a coil spring that provides sufficient elastic force and elastic displacement between an internal gear member made of metal and an external gear member. The effect of reducing generated noise and vibration can be maximized.

In addition, according to the elastic gear unit and the joint actuator having the same according to the present invention, durability can be improved compared to the case in which a member made of a non-metallic elastic material is inserted in order to secure sufficient elastic displacement to the joint actuator.

In addition, according to the elastic gear unit according to the present invention and the joint actuator having the same, in order to impart elasticity to the gear, it can be configured in the form of a single gear rather than a bulky gear assembly or gear assembly.

In addition, according to the elastic gear unit and the joint actuator having the same according to the present invention, it is applied to a wearable robot applied to pediatric patients with weak muscle strength or the disabled, etc., reducing mechanical resistance, simplifying the structure to reduce weight, and noise Over-vibration can be minimized, and further, a low-resistance auxiliary drive mode can be provided according to the wearer's operation intention, thereby minimizing the sense of rejection against the wearable robot.

1 is a side perspective view of a wearable robot to which a joint actuator using an elastic gear unit of the present invention can be applied.
FIG. 2 shows a front view of the wearable robot shown in FIG. 1.
3 and 4 are perspective views of the joint actuator to which the elastic gear unit according to the present invention is applied.
5 and 6 show a state in which the housing of the joint actuator to which the elastic gear unit according to the present invention is applied is removed.
7 shows a perspective view of an elastic gear unit and an output member according to the present invention.
8 is a side view showing an elastic gear unit and an output member according to the present invention.
9 is an exploded perspective view of an elastic gear unit and an output member according to the present invention.
10 shows a conceptual diagram of the operation of the elastic gear unit according to the present invention.
11 is an experimental data showing the torque of the drive motor corresponding to the deformation amount of the elastic member of the elastic gear unit in the joint actuator of the present invention.
FIG. 12 is an enlarged view of a red solid line area of FIG. 12.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed contents may be thorough and complete, and the spirit of the invention may be sufficiently conveyed to those skilled in the art. Throughout the specification, the same reference numbers indicate the same elements.

1 is a side perspective view of a wearable robot to which a joint actuator using an elastic gear unit of the present invention can be applied, and FIG. 2 is a front view of the wearable robot shown in FIG. 1.

Referring to FIGS. 1 and 2, in the present specification, the wearable robot 1000 may be a robot that assists walking motion by being worn on the lower body of a disabled person, an elderly person, or a patient (hereinafter, referred to as “wearer”). Here, the meaning of assisting the gait motion means providing a driving force for preserving insufficient muscle strength in the hip and knee joints to enable independent walking of the wearer with some of the lower body's motor functions.

The wearable robot 1000 includes a body 500 disposed at the waist of the wearer, and a pair of leg units 600l and 600r extending downward from the body 500 to support each leg of the wearer. Can include.

Here, the leg units 600l and 600r are provided at the hip joint and the knee joint, respectively, and provide auxiliary torque to the thigh and lower leg to assist the wearer's independent walking.

Accordingly, a driving device for providing a driving torque may be provided in a region corresponding to a hip joint and a knee joint of each of the leg units 600l and 600r. Each driving device may be composed of a joint actuator 100 that outputs a driving force through an elastic member or the like.

Each leg unit is connected to the joint actuators 100a and 100b, respectively, and is connected to the joint actuators 100a and 100b to support or assist the wearer's thigh and lower leg, and the femoral and lower leg members 410 and 430, and the lower leg member 430 ) And may be provided with a foot support portion 300 for supporting the wearer's foot.

The joint actuators 100a and 100b may be installed at the hip and knee joints of the wearer, respectively, a first joint actuator 100a is installed at a site where the pelvis and the thigh meet, and a second joint actuator 100a is installed at the knee at the boundary between the thigh and the lower leg. Joint actuator 100b may be installed. In the wearable robot illustrated in FIGS. 1 and 2, an example in which the joint actuator 100 is provided only in the hip and knee joints of the wearer is illustrated, but a separate driving device may be provided for the ankle joint as necessary.

And, each of the femoral member and the lower leg member (410, 430) may be provided with a wearing portion 420 in the form of a band for fixing the wearer's thigh and lower leg to the femoral member and the lower leg member (410, 430), , The driving force provided by each joint actuator 100 may eventually be transmitted to the wearer's thigh or lower leg through the wearing unit 420 to assist independent walking.

The joint actuator 100 provided in each joint to provide assistive power prevents injury to the wearer of the robot and provides accurate assistance according to the situation without feeling uncomfortable feelings such as pressure caused by wearing the robot. In addition to the program according to the auxiliary mode, it is required to determine the wearer's motion intention in response to the wearer's intention or movement, and to provide the required assisting force according to the determined motion intention.

As a method for determining the motion intention of the robot wearer, it is possible to determine the motion intention by detecting the muscle strength or electromyogram (electromyogram) of the robot wearer's muscle and using the detected muscle strength or EMG.

Such a sensor used to accurately measure muscle strength or EMG is expensive, has a large volume, and since the signal of the sensor is very sensitive to noise, it is difficult to use it practically in a mobile environment such as a wearable robot. Accordingly, the present invention applies the elastic gear unit to allow the user's movement as described later to determine the corresponding motion intention, and drives the driving motor 120 in a direction to remove the amount of deformation of the elastic gear, etc. While minimizing the mechanical resistance felt by the user, it is possible to determine the operation intention and provide an auxiliary driving force accordingly.

Hereinafter, the joint actuator 100 according to the present invention used in the wearable robot 1000 and the wearable robot according to the present invention applicable to the joint actuator 100 will be described in detail. In the embodiment shown in FIGS. 1 and 2, the joint actuator 100 installed in the hip joint and the knee joint may have different driving times or different magnitudes of driving force, but the joint actuator 100 described below has a common structure. It should be understood as a driving device that can be mounted on the hip joint or knee joint area respectively.

3 and 4 are perspective views of the joint actuator 100 to which the elastic gear unit according to the present invention is applied.

The joint actuator 100 is provided between the housings 110a and 110b forming an exterior, and the housings 110a and 110b, and at the same time, a driving module comprising an elastic gear unit according to the present invention described later (Fig. 5 And see FIG. 6).

The joint actuator 100 may be mounted on the outside of the housing so that the driving motor 120 is connected to the driving module inside the housing.

In addition, the joint actuator 100 may be equipped with an independent controller or PCB 115 separately from the control unit of the wearable robot.

Here, the joint actuator 100 includes a lighting unit (not shown) including at least one LED, etc. for displaying the direct motion state of the joint actuator 100 and an input unit for controlling separate motions of the joint actuator 100 (Not shown) may be provided.

The joint actuator 100 may include an output member 170 fastened to the femoral member of FIGS. 1 and 2 and the lower leg members 410 and 430 for supporting or assisting the wearer's thigh and lower leg.

The output member 170 may be configured to be fastened to a driving unit (refer to FIGS. 5 and 6) of an elastic gear unit to be described later.

The joint actuator 100 configured as described above may be mounted in the hip joint region and the knee joint region of the wearable robot, respectively, to drive the aforementioned femoral and lower thigh members 410 and 430 to provide an assistive force.

5 and 6 show a state in which the housing of the joint actuator 100 to which the elastic gear unit according to the present invention is applied is removed.

The joint actuator 100 according to the present invention has a rotation shaft 121 and is fastened to a driving motor 120 that provides a driving force through the rotation shaft 121 and the femoral and lower leg members 410 and 430 to assist joints. It may be configured with an output member 170 providing force, and at least one gear or gear unit for deceleration or torque amplification may be provided between the drive motor 120 and the output member 170 .

The joint actuator 100 according to the present invention includes a driving gear 130 connected to the rotation shaft of the driving motor 120, a reduction gear 140, 150 connected to the driving gear 130, and the reduction gear 140, 150. It may be configured to include an elastic gear unit 200 according to the present invention connected, and an output member 170 connected to the elastic gear unit 200.

Each gear or gear unit may be provided with a plurality of bearings (b), etc. interposed in the mounting hole formed on the inner surface of the housing constituting the joint actuator 100.

The reduction gears 140 and 150 may be provided in plural to amplify the torque of the joint actuator 100 according to the present invention, and the joint actuator 100 according to an embodiment of the present invention includes a first reduction gear 140 ) And a second reduction gear 150 may be included.

More specifically, the first reduction gear 140 is connected to the driving gear 130 mounted on the rotation shaft 121 of the driving motor 120 and has a larger diameter than the driving gear 130 ( 141) and a first small gear portion 142 having a diameter smaller than that of the first large gear portion 141, and the second reduction gear 150 is a first scavenging gear of the first reduction gear 140 It is connected to the fisherman 142, and may include a second small gear portion 151 that is larger than the first small gear portion 142 and a second small gear portion 152 having a diameter smaller than that of the second large gear portion 151. have.

Through the first reduction gear 140 and the second reduction gear 150, the driving force of the driving motor 120 may be amplified and transmitted to the elastic gear unit 200, which will be described later, through which the output member ( 170) is driven so that the femoral member 410 and the lower leg member 430 of the wearable robot 1000 may be configured to assist the movement of the thigh and lower leg of the wearer. A detailed transmission path of the driving force resulting from the driving motor 120 will be described later.

The driving motor 120 may be provided with a PCB 123 for driving a motor, and an encoder for measuring the angle, speed, or acceleration of the rotation shaft 121 of the driving motor 120 on the PCB 123 (e ) May be provided. The joint actuator of the present invention or a control unit of a wearable robot having the same controls each joint actuator 100 according to the detection information of the encoder (e) or a predetermined walking program to perform a walking driving mode or a low resistance operation to be described later. Allowable'low resistance auxiliary drive mode' can be provided.

The elastic gear unit 200 of the present invention connected to the second reduction gear 150 includes a gear member 210 connected to the second small gear part 152 of the reduction gear 150, and the gear member 210 It may be configured to include a driving member 220 accommodated and mounted inside, and an elastic member 230 interposed between the gear member 210 and the driving member 220. Detailed description of the elastic gear unit 200 will be delayed.

The driving member 220 of the elastic gear unit 200 is connected to the output member 170 to transmit the driving force of the driving motor 120 as a joint assisting force.

With such a structure, the joint actuator 100 according to the present invention includes the elastic gear unit 200 having the elastic member 230, and the driving gear 130 and the elastic gear unit 200 ) Is a relative rotation drive within a predetermined range as described later, and the rotation axis 121 of the driving motor 120, which is the rotation axis of the driving gear 130, and the rotation axis of the elastic gear unit 200 are configured to be parallel. Can be.

In addition, measuring the angle, speed, or acceleration of the rotation axis of the elastic gear unit 200 or the output member 170 by the movement of the wearer on the rotation axis of the elastic gear unit 200 or the output member 170 It may include an encoder (e) for. This will be described later.

7, 8 and 9 show the elastic gear unit 200 and the output member 170 according to the present invention, Figure 7 is a perspective view, Figure 8 is a side view, Figure 9 is an exploded perspective view.

The elastic gear unit 200 provided in the joint actuator 100 according to the present invention includes an arc-shaped gear member 210 having a gear mountain formed on an outer circumferential surface, a mounting part 223 mounted inside the gear member 210, and the mounting part A drive member 220 having a drive unit 221 provided on the coaxial with 223 and mounted between the mounting unit 223 of the gear member 210 and the drive member 220 to drive the gear member 210 and It may be configured with a plurality of elastic members 230 that allow relative rotation of the member 220 and provide an elastic restoring force.

Here, a ring-shaped ring frame (r) may be connected to a side surface of the gear member 210, and the ring frame (r) is the gear member 210 according to an operation form of the joint actuator 100 to be described later. It may be rotated integrally with the joint actuator 100 and is connected to be rotatable with one component in the housings 100a and 100b constituting the joint actuator 100, and may function to support the rotation of the gear member 210.

According to the drawings of the present specification, the ring frame (r) is formed integrally with the gear member 210, but the ring frame (r) is formed separately from the gear member 210 and then has a combined structure. May be.

The elastic member 230 is interposed between the gear member 210 and the driving member 220 to allow relative rotation of the gear member 210 or the driving member 220 within a predetermined range.

The gear member 210 may have a gear mountain formed on an outer circumferential surface thereof so that a driving force provided from the second small gear portion 152 of the second reduction gear 150 may be transmitted.

The drive member 220 mounted inside the gear member 210 is formed to protrude from the mounting portion 223 coaxially with the mounting portion 223 and the mounting portion 223 mounted inside the gear member 210 It may be configured to include a driving unit 221 coupled to the output member 170.

In addition, the gear member 210 may have at least one support portion 211 for supporting one end of the elastic member 230 to be described later on an inner peripheral surface of the gear member 210 to protrude inward.

Here, the elastic member 230 may be configured in the form of a coil spring, and the end portion of the elastic member 230 in the form of a coil spring is inserted into the support part 211 of the gear member 210 and fixed at least. One fixing part 211h may be formed.

The mounting portion 223 of the driving member 220 and the driving portion 221 may be integrally configured or each configured to be fastened.

8, the mounting portion 223 of the driving member 220 extends in the inner circumferential direction from the central portion 223c disposed inside the gear member 210, and the support portion of the gear member 210 At least one support arm 223w may be provided so as to support the end of the elastic member 230 having one end supported through 211.

The support arm 223w may be rotatably mounted along the inner circumferential surface of the gear member 210, and the rotation range of the support arm 223w of the driving member 220 on the inner circumferential surface of the gear member 210 A guide groove 212 for limiting may be formed.

The guide groove 212 may be provided to limit the rotation range of the driving member 220, and be configured in the form of a seating groove formed with a step 212s for limiting the rotation range of the driving member 220. I can.

The detailed configuration of each of the gear member 210 and the driving member 220 and their coupling structure can be changed according to various embodiments, but a non-limiting example with reference to FIG. 8 is a support part of the gear member 210 Three 211 are provided at intervals of 90 degrees, and two support arms 223w of the driving member 220 are provided at intervals of 90 degrees, respectively, between the mutually adjacent support portions 211 of the gear member 210 Can be placed on

Through this, a total of four elastic members 230 are interposed between the support part 211 of the gear member 210 and the support arm 223w of the driving member 220 to support the support arm of the driving member 220 ( 223w) of the gear member 210 is allowed to rotate inside the guide groove 212, but an elastic restoring force may be provided.

Such an elastic restoring force may provide a smooth feeling of operation in both an active walking drive mode or a passive low-resistance assist drive mode, and may provide an effect of minimizing noise and vibration generated at the same time.

According to the drawings of the present specification, a total of four elastic members 230 constituting the elastic gear unit 200 are provided, and each of the elastic members 230 is shown to be individually configured independently, but another embodiment According to the above, at least some of the plurality of elastic members 230 may be formed to have an interconnected structure between the elastic members 230 adjacent to each other.

As an example, although not shown through the drawings, at least some of the elastic members 230 of the plurality of elastic members 230 are supported by the support 211 of the gear member 210 or the driving member 220 It may be arranged to pass through the arm 223w, and for this purpose, a part of the coil of the elastic member 230 in the form of a coil spring is supported by the support 211 of the gear member 210 or the driving member 220 It may be configured in an open state to pass through the arm 223w.

Such an interconnected structure between the adjacent elastic members 230 may provide a more stable elastic restoring force for the gear member 210 or the driving member 220, and the gear member 210 and the drive It is possible to reduce the possibility of separation from the coupling structure between the members 230.

10 shows a conceptual diagram of the operation of the elastic gear unit 200 according to the present invention.

The driving part 221 of the driving member 220 of the elastic gear unit 200 is connected to the output member 170.

Therefore, the wearer of the wearable robot moves the thigh or lower leg while the driving motor is stopped, and the femoral and lower leg members 410 and 430 and the output member 170 fastened thereto are counterclockwise. When rotated θ degrees in the direction, the driving member 220 of the elastic gear unit 200 connected to the output member 170 may rotate θ degrees in a counterclockwise direction.

When the elastic gear unit 200 is omitted in the joint actuator 100 according to the present invention shown in FIGS. 5 and 6, when the robot wearer attempts to move in a state in which the driving motor 120 is not driven, Due to the mechanical resistance of each gear, the wearer's movement is impossible or a considerable force is required for the movement, so that the robot wearer feels considerable pressure or discomfort in the state of wearing the robot.

Accordingly, the joint actuator 100 of the present invention has a driving motor 120 in addition to a walking driving mode in which the driving motor 120 of the wearable robot is driven to actively assist the wearer's walking in order to alleviate such a feeling of pressure or discomfort. In a state in which) is not driven, the assistive force can be provided even in a low-resistance assist drive mode that passively provides assistive force according to the movement of the wearer.

In order to provide assistance according to the movement of the wearer in the low-resistance assist driving mode, it is necessary to first identify or determine the motion intention of the wearable robot wearer.

As described above, since the muscle strength sensor or the EMG sensor for precisely measuring the user's muscle strength or EMG is expensive, bulky, and the sensor signal is very sensitive to noise, it is practically used in a mobile environment such as a wearable robot. Since there is a problem that is difficult to use, the present invention implements a low-resistance auxiliary drive mode by applying the elastic gear unit 200 to a joint actuator, allowing a certain degree of movement of the robot wearer, and detecting it when movement occurs. .

When the robot wearer moves the thigh or lower leg, it is sensed and the driving motor is driven to provide an assisting force for rotating the femoral member or the lower leg member in the corresponding movement direction, thereby providing a low-resistance assist driving mode.

That is, in the present invention, when a user's motion is detected while the drive motor 120 of the above-described joint actuator 100 is stopped, it is assumed that the motion of the motion is intended, and the drive motor ( 120) can be used to provide assistance.

The movement of the wearer is premised on allowing the movement of the output member 170 of the joint actuator 100 connected to the femoral member or the lower leg member.

Therefore, when the output member 170 is rotated according to the movement of the robot wearer, the driving unit 221 of the driving member 220 connected to the output member 170 is rotated, so that the driving member 220 rotates accordingly. Torque T1 is applied.

Here, the driving member 220 is connected via the gear member 210 and the elastic member 230, the rotation torque applied to the driving member 220 by the mechanical impedance of the driving motor 120 (T1) rotates only the driving member 220.

At this time, the support arm 223w constituting the mounting portion 223 of the driving member 220 that is rotated has a step 212s formed on the inner circumferential surface of the gear member 210 and is determined in advance on the divided guide groove 212 It rotates θ degrees in the angular range.

The support arm 223w may be allowed to rotate within a range of the guide groove 212 formed on the inner circumferential surface of the gear member 210, and each of the elastic members 230 is a support arm of the driving member 220 ( 223w) and the support portion 211 of the gear member 210, respectively, to generate an expansion and restoring force upon compression, and a contraction and restoring force upon tensioning.

Therefore, when each of the elastic members 230 is provided between the support arm 223w of the driving member 220 and the support part 211 of the gear member 210, when the driving member 220 is rotated, a gear The first elastic member 230a and the second elastic member 230b sandwiching the support part 211 of the member 210 generate a contraction restoration force and an expansion restoration force, respectively.

Since the elastic member 230 is interposed between the driving member 220 and the gear member 210, the wearer can rotate the joint within a predetermined range while feeling only elastic resistance instead of a large mechanical resistance, and the elastic gear unit 200 ) Or the encoder (e) mounted on the rotation axis of the output member 170 detects such rotation, and the control unit of the joint actuator 100 or the wearable robot 1000 is the encoder (e) detection information According to the driving motor 120 is driven in the direction of movement of the joint, and the driving force of the driving motor 120 provides an auxiliary torque T2 to the gear member 210 of the elastic gear unit 200, It can assist in movement.

Unlike the active walking driving mode of the robot wearer, this low-resistance driving mode is a low-resistance auxiliary driving mode that provides assistance according to the movement of the wearer, and provides auxiliary torque in the direction in which elastic deformation of each elastic member 230 is removed. do.

On the other hand, in a general walking driving mode, a driving torque may be transmitted to the gear member 210 to actively assist the wearer's walking, and a driving torque may be transmitted to the driving member 220 through the elastic member 230. have.

In the latter walking driving mode, the role of the elastic member 230 is used as a power or torque transmission means, not a configuration for allowing the movement of the robot wearer in the non-driving state of the driving motor 120.

Due to the auxiliary torque provided in the auxiliary driving mode in which the low-resistance auxiliary driving of the joint actuator 100 is performed, the wearer can minimize the resistance of the joint actuator even in the robot wearing state, or, furthermore, move with a feeling that the body becomes lighter. It can be possible.

As described above, according to the present invention, the joint actuator 100 adopts a structure in which the wearer of the robot can realize a more natural and comfortable movement when the driving motor 130 is driven, and the driving motor 120 In order to allow the movement of the wearer even in a non-driving state, the elastic gear unit 200 is provided, and the elastic gear unit 200 adopts a structure capable of allowing movement toward the output member 170.

Therefore, when the movement of the wearer is detected while the driving motor 130 is stopped and it is determined that the wearer's motion intention is determined, the control unit of the joint actuator 100 or the wearable robot 1000 By driving the drive motor 120 of the joint drive unit 100 of, the gear member 210 constituting the elastic gear unit 200 is generated by generating a driving torque to drive the gear member 210 in the rotational direction of the driving member 220 A low resistance auxiliary driving mode that minimizes mechanical resistance or impedance of the joint actuator 100 may be provided, and such a low resistance auxiliary driving mode may be provided between active walking driving modes.

The amount of elastic deformation of the elastic member 230 of the elastic gear unit 200 is determined by the control unit of the joint actuator 100 or the wearable robot 1000 providing a reference for applying an appropriate torque to the joint actuator 100. Bar, the elastic gear unit 200 needs to be designed so that the amount of elastic deformation caused by the wearer's walking intention in the low resistance driving mode can be converted into linear data as an accurate value.

If torque is applied to the output member 170 and transmitted to the elastic gear unit 200 according to the wearer's walking intention, the control unit provides an appropriate torque for the amount of deformation of the elastic member 230 of the elastic gear unit 200. Is calculated, and the corresponding torque is transmitted to the elastic gear unit 200 and the output member 170 through the driving motor 130.

However, the joint actuator 100 is configured to include the drive motor 130, reduction gears 140 and 150, the elastic gear unit 200, etc., and due to the mutual coupling structure of various configurations, the elastic member ( 230) may cause an error in the elastic deformation amount data.

Since the joint actuator 100 as in the present invention includes various components in a mutually coupling structure, the components interposed between the output member 170 and the elastic gear unit 200 increase, and the process of mounting the elastic member When the elastic member itself needs to be subjected to deformation, the estimated deformation amount of the elastic member calculated based on the data measured by the encoder and the actual deformation amount of the elastic member 230 of the elastic gear unit 200 are determined by the elastic member. An error in the compression direction or the direction in which compression is released may increase.

Theoretically, the elastic force of the elastic member can be determined by the amount of deformation and the elastic modulus, and conversely, the torque or force transmitted through the elastic member can be determined only by the elastic modulus and the amount of deformation. A phenomenon in which the difference between the elastic force transmitted or output through the elastic member in the direction in which the amount of deformation increases and the direction in which the amount of deformation decreases even in the elastic member having the same amount of deformation due to the shape of a deformed state or the like occurs is called a hysterisis of the elastic member.

In order to determine the size of the auxiliary torque (see T2 in FIG. 10) for assisting the aforementioned low-resistance auxiliary driving mode, the wearer overcomes the mechanical resistance of the robot and accurately sets the size of the driving torque (see T1 in FIG. 10) to drive the joint. It is necessary to determine, and for this purpose, it is preferable that the variation of the elastic force according to the deformation direction of the elastic member, that is, the hysteresis phenomenon, is minimized.

Therefore, in the case of the joint actuator 100 according to the present invention, the elastic member 230 is not provided in, for example, the first reduction gear 140 or the second reduction gear 150 mounted between the driving motor and the output member. Without interposing an elastic member between the driving member 220 and the gear member 210 directly connected to the output member to reduce the deformation amount error of the elastic member 230 due to the movement of the robot wearer, and, in addition, the elastic member 230 The first reduction gear 140 or the second reduction gear 150 is disposed inside the gear member 210 having a larger diameter to reduce the amount of deformation of the elastic member in the process of mounting the elastic member, so that the hysteresis phenomenon of each elastic member The deviation of the elastic force according to this was minimized.

With this structure, it is possible to accurately determine the size of the auxiliary torque (see T2 in FIG. 10) for assisting the low-resistance auxiliary driving mode through rotation angle information of the joint detected by the encoder.

FIG. 11 is experimental data showing the torque of the driving motor corresponding to the deformation amount of the elastic member of the elastic gear unit in the joint actuator of the present invention, and FIG. 12 is an enlarged view of the red solid line area (spring section) of FIG. .

In the experiment of FIG. 11, the output member 170 of the joint actuator according to the present invention is not rotated, but a torque measuring device (dynamometer, etc.) capable of measuring the torque (Nm) is installed, and the driving motor is operated to operate the encoder of the driving motor. Through the method of measuring the torque generated by the output member according to the rotation angle of the drive motor.

In the section where the elastic member can be compressed or elongated, the torque is transmitted in proportion to the amount of elastic deformation, but the elastic member does not behave elastically in the locking section, which is a section where further elastic deformation is impossible, and torque or force is transmitted like a single rigid body. .

Therefore, in order to minimize the hysteresis phenomenon, the deviation of the measured force in the direction in which the displacement amount (or angle) increases and the direction in which the displacement amount (or angle) increases in the spring section must be minimized.

Since the output member 170 is in a fixed state, it may be assumed that the measured value measured by the encoder of the driving motor corresponds to the amount of deformation (deformation angle) of the elastic member.

As shown in FIGS. 11 and 12, when the elastic member 230 of the elastic gear unit 200 is deformed by the driving torque of the driving motor, the measured torque according to the deformation direction of the elastic member 230 It can be seen that the deviation is not large and a generally linear change can be obtained.

That is, it seems that there is no deviation in FIG. 11, and it can be confirmed that the band width according to hysterisis is at a fine level even in the enlarged view of FIG. 12, so that the deviation in the deformation direction of the elastic member can be minimized. I can.

That is, although the coil spring is mounted in an arc shape inside the gear member, the outer diameter of the gear member is larger than the outer diameter of the reduction gear and is installed close to the output member side, and as shown in the enlarged view of FIG. 12, the history of the elastic member It can be seen that the phenomenon can be minimized.

As described above with reference to FIG. 10, the hysteresis minimization structure causes contraction and elongation of the plurality of elastic members according to the position of the support arm or the like according to the driving motor or the output member, so that one single coil spring It is estimated that the hysteresis phenomenon is further reduced than the case of configuring the elastic member.

Due to this structure, the measured torque transmitted through the elastic member according to the deformation direction of the elastic member is generally linearly proportional to the deformation amount (deformation angle) of the elastic member, and in the walking driving mode or the low resistance auxiliary driving mode as a joint actuator. Accurate delivery may be possible.

Although the present specification has been described with reference to preferred embodiments of the present invention, those skilled in the art will variously modify and change the present invention within the scope not departing from the spirit and scope of the present invention described in the claims described below. You will be able to do it. Therefore, if the modified implementation basically includes the elements of the claims of the present invention, all should be considered to be included in the technical scope of the present invention.

100: joint actuator
120: drive motor
130: drive gear
140: first reduction gear
150: second reduction gear
170: output member
200: elastic gear unit
210: gear member
220: driving member
230: elastic member

Claims (11)

A ring-shaped ring frame is provided on a side surface, and a gear member in an arc shape having a gear mountain formed on an outer circumferential surface thereof;
A driving member having a mounting portion mounted inside the gear member and a driving portion disposed coaxially with the mounting portion; And,
And a plurality of elastic members in the form of coil springs mounted between the gear member and the mounting portion of the driving member to allow relative rotation of the gear member or the driving member while providing an elastic restoring force; and
The gear member has a plurality of support portions protruding inwardly for supporting one end of at least one elastic member on an inner peripheral surface,
The mounting portion of the driving member includes a plurality of support arms extending in a direction of an inner circumferential surface of the gear member to support the other end of each elastic member supported by the support portion of the gear member,
In the gear member, a plurality of guide grooves for limiting the rotation range of the support arm of the driving member are formed on the inner circumferential surface of the gear member formed with the support part protruding,
An elastic gear unit, wherein an outer end of the support arm of the driving member is rotated while seated in the guide groove, and the other end of the elastic member is supported at an inner end of the driving member. delete The method of claim 1,
Three support portions of the gear member are provided at intervals of 90 degrees, and two support arms of the driving member are provided at intervals of 90 degrees, each of which is disposed between mutually adjacent support portions of the gear member, and four elastic members are provided at the Elastic gear unit, characterized in that disposed between the support portion of the gear member and the support arm of the drive member. delete delete The method of claim 1,
An elastic gear unit, characterized in that at least some of the elastic members of the plurality of elastic members are configured in a state in which a part of the coil is unfolded so as to be disposed via a support part of the gear member or a support arm of the driving member. Drive motor;
A drive gear mounted on the rotation shaft of the drive motor;
A first reduction gear connected to the driving gear and having a first large gear portion having a larger diameter than the driving gear and a first small gear portion having a diameter smaller than that of the first large gear portion;
A second reduction gear connected to a first small gear portion of the first reduction gear and having a second large gear portion having a larger diameter than the first small gear portion and a second small gear portion having a diameter smaller than that of the second large gear portion;
The elastic gear unit of any one of claims 1, 3, and 6, wherein a gear member is connected to the second small gear part of the second reduction gear;
Joint actuator comprising; an output member fastened to the driving part of the driving member of the elastic gear unit and coupled to the thigh member or lower leg member of the wearable robot. The method of claim 7,
A pair of encoders for measuring the angle, speed, or acceleration of the rotation shaft of the elastic gear unit and the rotation shaft of the drive motor; And a controller for controlling the drive motor according to information sensed by the encoder or a predetermined walking program. The method of claim 8,
The control unit drives the driving motor according to the walking mode, the driving force of the driving motor is transmitted to the output member through the elastic gear unit, and when the wearer is walking, the output member of each joint actuator is each femoral member or Joint actuator, characterized in that to assist the wearer's walking by assisting the rotational drive of the lower leg member. The method of claim 8,
When the motor constituting the joint driver is stopped and the output member constituting the joint driver rotates and the rotation of the elastic gear unit or the output member is sensed by an encoder provided in the elastic gear unit, the controller A joint actuator, characterized in that driving the drive motor to provide an auxiliary force in the rotational direction of the elastic gear unit or the output member. The method of claim 7,
An outer diameter of a gear member constituting the elastic gear unit is larger than an outer diameter of the large gear portion of the first reduction gear or the second reduction gear.

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