KR101999057B1 - Series elastic actuator and controller including the same - Google Patents

Abstract

Disclosed is a series elastic actuator and a controller including the same. According to one embodiment, the series elastic actuator comprises: a power part providing power; an output part configured to be spaced apart from the power part by a predetermined interval and having an external force applied to one side; and an elastic part disposed between the power part and the output part and connected in series with each of the power part and the output part, and displaced by elasticity of at least one or more elastic body according to the external force applied to the output part. Therefore, the present invention is to provide a technique for measuring and compensating for the external force applied on the actuator by the displacement of the elastic body.

Description

TECHNICAL FIELD [0001] The present invention relates to a series elastic actuator and a controller including the elastic actuator.

The following embodiments relate to a series elastic actuator and a controller including the series elastic actuator. More particularly, the present invention relates to a series elastic actuator having a series elastic component attached to an actuator output side and a controller including the series elastic actuator.

Actuated geared electric and hydraulic actuators do not produce accurate output relative to the command (force) due to limitations of high impedance, traction, and bandwidth. In these traditional actuator systems, the addition of series elastic elements provides low impedance and traction, good bandwidth, and enables more precise force-control actuating techniques.

The Series Elastic Actuator (SEA) was first introduced in artificial intelligence labs led by Professor Rodney Brooks of MIT and is applied to Domo robots and bipedal robots.

In series elastic actuators, the rigid load cells used in conventional actuators are replaced by highly flexible elastic elements. The replaced elastic element greatly increases the control gain of the actuator, and the increased control gain greatly reduces the impedance and reduces the effect of static friction. As a result, the component that affects the output of the actuator is reduced, and high-performance force control is possible. Further, since the increased control gain greatly reduces the impedance, it is possible to use an actuator with a smaller volume and higher precision than the conventional one.

The series elastic actuator has characteristics such as high speed, high gear ratio, and anti-drivability. By this improvement, the elastic element can be applied to the electric and hydraulic actuators used conventionally, and the humanoid joint such as the robot arm, And is being studied and developed.

A series elastic actuator developed and studied conventionally uses an expensive sensor such as a torque sensor or a strain gauge to measure an external force acting on a load end. However, since these expensive sensors can obtain precise measurement values, high cost and large volume charge for mounting are required, methods for obtaining precise measurement values at low cost are being studied.

Korean Patent Publication No. 10-2015-0078303

Embodiments describe a series elastic actuator and a controller including the same. More specifically, an elastic body is connected to an actuator output side to measure and compensate an external force acting on the actuator due to the displacement of the elastic body.

Embodiments are characterized in that an elastic body is connected in series between the output part of the actuator and the motor and the force acting on the load end is measured by using an infrared sensor at both ends of the elastic body to measure the external force, An actuator and a controller including the same.

A series elastic actuator according to one embodiment, comprising: a power section for providing power; An output unit configured to be spaced apart from the power unit by a predetermined distance and having an external force acting on one side thereof; And an elastic portion disposed between the power portion and the output portion and connected in series with each of the power portion and the output portion and displaced by the elasticity of at least one elastic body as the external force acts on the output portion .

The power unit includes: a motor; A ball screw driven by the motor; And a fixing plate fixed to an end of the ball screw and moving up and down according to rotation of the ball screw, wherein the ball screw is driven by the motor to adjust a height of the series elastic actuator.

And an infrared sensor configured to measure the displacement magnitude due to elasticity, the infrared sensor being configured at both ends of the at least one elastic body, wherein the infrared sensor measures the magnitude of the external force acting by measuring the displacement magnitude due to the elasticity .

The elastic part includes a first elastic body disposed on the upper side with respect to the fixed plate and a second elastic body disposed on the lower side with respect to the fixed plate. The first elastic body is formed at both ends of the first elastic body, And an infrared sensor for measuring the infrared ray.

The power unit may cancel the external force by driving the motor by a height corresponding to force feedback to move the fixing plate through the ball screw.

The power unit may include: a first pulley connected to the ball screw; And a second pulley connected to the motor and connected to the first pulley to transmit power of the motor.

The power section may be connected in parallel with the output section, the elastic section and the motor by the first pulley and the second pulley.

Wherein the output section includes: a load plate having one side to which the external force acts; A support plate spaced apart from the load plate by a predetermined distance; And a plurality of support rods connecting between the load plate and the support plate, wherein the load plate and the support plate can be disposed around the ball screw.

Wherein the elastic portion includes two plates fixed to the plurality of support rods in a spaced-apart relationship, one of the two plates being fixed to the plurality of support rods including the support plate, The other one of the plates being movable relative to the plurality of support rods, the first elastic member being disposed between the two plates, the first elastic member being disposed on the load side of the plurality of support rods with respect to the fixing plate, And a second elastic body disposed on the side of the second elastic body.

The first elastic body and the second elastic body may be composed of two springs each formed on an outer peripheral surface of the plurality of support rods.

When the external force acts, the first elastic body disposed on the upper side of the fixing plate is compressed by a predetermined distance, and the second elastic body disposed on the lower end of the fixing plate can be stretched by a predetermined distance.

The compressed distance of the first elastic body may be measured using the infrared sensor, and the magnitude of the external force may be calculated by the Hooke's law using the compressed distance measured.

According to another aspect of the present invention, there is provided a controller comprising: a power unit that provides power; an output unit that is spaced apart from the power unit by a predetermined distance and has an external force acting on one side; And a resilient portion connected in series with the power portion and the output portion, the resilient portion being displaced by the elasticity of at least one elastic body as the external force acts on the output portion and measuring the magnitude of the external force. And a PD controller that receives the calculated external force acting on the output portion of the series elastic actuator and uses the difference between the calculated external force and the value calculated in association with the encoder value as input to the power portion of the series elastic actuator And the power unit generates a force corresponding to the input value and can operate in a direction opposite to the direction of the force applied to the output unit.

The power unit includes: a motor; A ball screw driven by the motor; And a fixing plate fixed to an end of the ball screw and moving up and down according to rotation of the ball screw, wherein the ball screw is driven by the motor to adjust a height of the series elastic actuator.

The elastic part includes a first elastic body disposed on the upper side with respect to the fixed plate and a second elastic body disposed on the lower side with respect to the fixed plate. The first elastic body is formed at both ends of the first elastic body, Wherein the power unit drives the motor by a height corresponding to a force feedback to move the fixing plate through the ball screw, thereby completing the external force Compliance < / RTI >

According to the embodiments, the elastic body is connected in series between the output part of the actuator and the motor, and the force acting on the load end is measured by using an infrared sensor at both ends of the elastic body, A series elastic actuator and a controller including the series elastic actuator can be provided.

According to embodiments, an externally applied force can be measured and an appropriate force or position corresponding to a measured value can be output, thereby forcing the force in an application such as position, torque, force control, or moving the position to another position The present invention can provide a series elastic actuator capable of minimizing force, position control error, and a controller including the series elastic actuator.

1 is a view schematically showing a structure of a series elastic actuator according to an embodiment.
2 is a view illustrating an FSEA type series elastic actuator according to an embodiment.
3 is a view for explaining an RFSEA type series elastic actuator according to another embodiment.
4 is a schematic diagram of a controller including a series elastic actuator according to one embodiment.
5 is a diagram illustrating a mechanism for force feedback of a series elastic actuator according to an embodiment.
6 shows a perspective view of a series elastic actuator according to one embodiment.
7 is an exploded perspective view of a series elastic actuator according to an embodiment.
8 shows a front view of a series elastic actuator according to one embodiment.
9 shows a side view of a series elastic actuator according to one embodiment.
10 is a perspective view of a motor portion of a series elastic actuator according to an embodiment.
11 shows a perspective view of an output portion and an elastic portion of a series elastic actuator according to an embodiment.

Hereinafter, embodiments will be described with reference to the accompanying drawings. However, the embodiments described may be modified in various other forms, and the scope of the present invention is not limited by the embodiments described below. In addition, various embodiments are provided to more fully describe the present invention to those skilled in the art. The shape and size of elements in the drawings may be exaggerated for clarity.

The following embodiments relate to a Series Elastic Actuator (SEA) to which a series elastic component is attached at the output side of an actuator. More specifically, an elastic member is connected in series between the output portion of the actuator and the motor To a series elastic actuator for measuring a force acting on an actuator by displacement of an elastic body, and a controller including the same.

1 is a view schematically showing a structure of a series elastic actuator according to an embodiment.

Referring to FIG. 1, a series elastic actuator 100 according to an embodiment includes a motor 110, an output unit 120, and an elastic body 130. The elastic body 130 is connected in series between the motor 110 and the output unit 120 and can measure a force acting on the output unit 120 due to the displacement of the elastic body 130. Here, at least one spring or the like may be used as the elastic body 130, for example.

In particular, the series elastic actuator 100 may further include an infrared sensor, and an infrared sensor may be formed at both ends of the elastic body 130 to measure an external force through the displacement magnitude of the elastic body 130 displaced by an external force .

More specifically, the infrared sensor is mounted on both ends of the elastic body. When the elastic body is loaded by a load applied by an external object, the infrared sensor uses a compressed length and a predetermined elasticity coefficient of the elastic body, = kx ) can be measured.

2 is a view illustrating an FSEA type series elastic actuator according to an embodiment. And FIG. 3 is a view for explaining an RFSEA type series elastic actuator according to another embodiment.

As shown in FIGS. 2 and 3, the series elastic actuator is classified into Force-sensing Series Elastic Actuator (FSEA), Transmitted Force-sensing Series Elastic Actuator (TFSEA), and Reaction Force-sensing Series Elastic Actuator (RFSEA) .

2 shows an example of a force-sensing series Elastic Actuator (FSEA) type among series elastic actuators. More specifically, FIG. 2A shows a schematic structure of an FSEA, FIG. 2B shows an FSEA (C) shows the model of the FSEA, and (d) shows the high output impedance model of the FSEA.

The series elastic actuator of the FSEA type may include a motor 210, an output unit 220 and an elastic body 230 connected in series between the motor 210 and the output unit 220, A box 211 can be constructed.

In particular, the series elastic actuator of the FSEA type may further include a ball screw, that is, a combination of a motor 210, a ball screw, an elastic body 230, and an output unit 220 in order, Can be measured with the elastic body 230. [

In this case, a high gear ratio can be obtained through the ball screw, and the external force can be measured using the displacement of the elastic body 230 without using an additional torque sensor. Therefore, by measuring the external force through the displacement of the elastic body 230, the torque sensor is not used, which makes it possible to reduce the cost and simplify the structure. In addition, since the expensive and bulky load cell is replaced with a simple spring-like elastic body and position measuring device, the overall cost and weight can be reduced. The elastic body is used not only for measuring external force but also for absorbing external impact .

The series elastic actuators below are based on the FSEA type.

3 shows an example of an RFSEA (Reaction Force-sensing Series Elastic Actuator) type among series elastic actuators. More specifically, FIG. 2A shows a schematic structure of RFSEA, and FIG. (C) shows a model of RFSEA, and (d) shows a high output impedance model of RFSEA.

The series elastic actuator of the RFSEA type may include a motor 310, an output unit 320, and an elastic body 330, and a gear box 311 may be formed at one side of the motor. Here, the motor 310 may be connected in series to one side of the elastic body 330 and the output unit 320 may be connected to the gear box 311 connected to the motor 310 or the motor 310 in series, 320 can be measured by the elastic body 330.

4 is a schematic diagram of a controller including a series elastic actuator according to one embodiment.

Traditional techniques for force control include direct drive current control, geared actuator current control, low friction cable drive current control, load cell with force feedback and fluid pressure control. However, in order to implement these force control techniques, additional devices such as a current sensor, a cable, a load cell, and a fluid pressure regulator are required. In this embodiment, a compliance control, which is one of the force-feedback control techniques, can be used to control the force acting on the elastic body by arranging elastic elements in series for force control.

In general, a compliance controller using a compliance control method is also referred to as adaptive control, and is often used in an end effector such as a joint of a manipulator or a gripper. The compliance controller can measure the externally applied force and output the appropriate force or position corresponding to the measured value. This minimizes force and position control errors such as imposing force on the position, torque, and force control, or moving the position to another position.

Since the elastic body mounted on the series elastic actuator basically operates like a low pass filter, the vibration of high frequency is automatically reduced. In the case of impact or vibration above a certain force, the elastic body does not act as a low-pass filter, so that compliance control can be performed to follow the appropriate force and position within the variable range of the series elastic actuator and the allowable impact amount.

Referring to FIG. 4, the controller may include the series elastic actuator 400 described above.

First, when a force is applied to the output portion 420 of the series elastic actuator 400, the elastic body 430 is compressed and the displacement X ₁ of the output portion 420 is changed. The length of the displacement X _l of the changed output portion 420 is a, and the measurement by an infrared sensor, which depends on the series elastic actuator 400, the elastic coefficient k _s of the displacement X _l and the elastic body 430 of the output unit 420 The force F _l acting on the output 420 by the multiplied Hook's law (F _l = X _l k _s ) is calculated.

The calculated force F _l is used as the input of the PD controller and the output of the PD controller derived using the difference between the F _d value and the measured F _l value calculated in conjunction with the encoder value of the motor 410 And is used as an input of the motor 410 mounted in the elastic actuator 400. [

Motor (410) receiving the output of the controller as input, thereby operating the motor 410 to generate a force F _m, in the direction opposite to the direction of the force applied to the output unit 420 by the force F _m corresponding thereto. So that the external force acting thereon can be canceled.

5 is a diagram illustrating a mechanism for force feedback of a series elastic actuator according to an embodiment.

Referring to FIG. 5, a mechanism for force-feedback of a series elastic actuator according to an embodiment is shown. For example, the series elastic actuator includes a top plate 510 A first elastic body 540 disposed between the middle plate 520 and the lower plate 530 and between the upper plate 510 and the middle plate 520 and a second elastic body 540 disposed between the middle plate 520 and the lower plate 530. [ (550). Here, the first elastic body 540 and the second elastic body 550 may be formed of a plurality of springs, respectively. At this time, the plurality of springs used in the series elastic actuator have the same spring constant, and the tensile and compression lengths are also the same.

First, the upper plate 510 directly receives an external force, and the upper plate 510 and the lower plate 530 are connected to each other and always maintain the same interval. The intermediate plate 520 is disposed between the upper plate 510 and the lower plate 530 and is disposed movably by the first and second elastic bodies 540 and 550. For example, the middle plate 520 is attached to the ball screw, and the external force can be canceled by moving the middle plate 520 by driving the motor by the height corresponding to the force feedback through the ball screw.

As shown in FIG. 5 (a), when no external force acts, the first elastic body 540 and the second elastic body 550 are not deformed, but remain in a rest state while maintaining the height L.

When the external force F acts on the upper plate 510, the first elastic body 540 disposed at the upper end of the middle plate 520 is compressed by DELTA X as shown in Fig. 5 (b) The second elastic body 550 disposed at the lower end of the first elastic body 520 is stretched by DELTA X. At this time, the reduced height (DELTA X) of the first elastic body 540 is measured using an infrared sensor, and the measured height is applied to the Hooke's law (F = k * DELTA X) have. It is also possible to calculate the magnitude of the external force F by measuring the height of the second elastic member 550 using an infrared sensor.

5C, the motor is driven by the reduced height DELTA X of the first elastic body 540 due to the external force F to raise the middle plate 520, and the height of the upper plate 510 is increased by DELTA X so that the external force F is compensated.

In the following, a series elastic actuator according to one embodiment will be described in more detail as one example.

FIG. 6 is a perspective view of a series elastic actuator according to an embodiment, and FIG. 7 is an exploded perspective view of a series elastic actuator according to an embodiment. FIG. 8 is a front view of a series elastic actuator according to an embodiment, and FIG. 9 is a side view of a series elastic actuator according to an embodiment. 10 is a perspective view of a motor portion of a series elastic actuator according to an embodiment, and FIG. 11 is a perspective view of an output portion and an elastic portion of the series elastic actuator according to an embodiment.

6-11, a series elastic actuator 600 according to one embodiment may include a power section 610, an output section 620, and an elastic section 625. [ And may further include an infrared sensor according to an embodiment.

The power section 610 provides power, and the power section 610 is fixed to the motor 611, the ball screw 612 driven by the motor 611, and the ball screw 612, And a fixing plate 618 which moves in the vertical direction in accordance with the rotation of the pressing plate 612. At this time, a ball net 617 may be formed to fix the fixing plate 618 to the ball screw 612, and a bearing 615 may be formed at both ends of the ball screw 612.

Here, the ball screw 612 is driven by the motor 611 to adjust the height of the series elastic actuator 600. The power unit 610 drives the motor 611 by a height corresponding to the force feedback to move the fixing plate 618 through the ball screw 612, thereby canceling the external force.

The power unit 610 may include a pulley 619 that connects the motor 611 and the ball screw 612. More specifically, the power section 610 includes a first pulley 619 connected to the ball screw 612 and a motor 611 connected to the motor 611 and connected to the first pulley 619 using a belt, And a second pulley 619 for transmitting the power of the second pulley 619. At this time, the power section 610 is connected to the output section 620 and the elastic section 625 and the motor 611 in parallel by the first pulley 619 and the second pulley 619, thereby minimizing the volume .

The power unit 610 includes a lower plate 613 for connecting the motor 611 and the ball screw 612 in parallel and an upper plate 614 formed at the upper end of the ball screw 612, A plurality of guide rails 616 may be formed between the upper plate 613 and the upper plate 614. [

The output unit 620 is spaced apart from the power unit 610 by a predetermined distance, and an external force may act on one side.

The output unit 620 includes a load plate 621 on one side of which an external force acts, a support plate 623 spaced apart from the load plate 621 by a predetermined distance, and a load plate 621 and a support plate 623 And the load plate 621 and the support plate 623 may be disposed around the ball screw 612. The support plate 623 may be formed of a plurality of support rods 622,

The elastic portion 625 is disposed between the power portion 610 and the output portion 620 and is connected in series with the respective power portion 610 and the output portion 620. An external force acts on the output portion 620 It can be displaced by the elasticity of at least one or more elastic bodies.

For example, the elastic portion 625 may include a first elastic body disposed on the upper side with respect to the fixed plate 618 and a second elastic body disposed on the lower side.

The elastic portion 625 includes two plates 623 fixed to a predetermined spaced apart state connected to the plurality of support bars 622. One of the two plates 623 includes a support plate 623, And the other one of the two plates 623 is movable relative to the plurality of support rods 622. In this case, Here, the two plates 623 can be fixed by at least one of the fixing bars 624.

The resilient portion 625 is disposed between the two plates 623 so that the first elastic body disposed on the load side of the plurality of support rods 622 and the support portion side of the plurality of support rods 622 And a second elastic body disposed on the second elastic body.

For example, the first elastic body and the second elastic body may be composed of two springs each formed on the outer peripheral surface of the plurality of support rods 622. That is, the elastic portion 625 may be composed of four springs for external force measurement. Further, a plurality of support rods 622 may also be composed of four to fix the four springs.

And an infrared sensor configured at both ends of at least one elastic body to measure the displacement magnitude due to elasticity. Such an infrared sensor can measure the magnitude of the external force acting by measuring the displacement magnitude due to elasticity.

In particular, the infrared sensor is formed at both ends of the first elastic body, and the magnitude of the external force can be measured by measuring the magnitude of displacement due to elasticity. On the other hand, the infrared sensor is configured at both ends of the second elastic body, and it is also possible to measure the magnitude of the external force by measuring the displacement magnitude due to elasticity.

As described above, in the case of the series elastic actuator 600 according to the embodiment, when an external force is applied, the first elastic body disposed on the upper side of the fixing plate 618 is compressed by a predetermined distance, The second elastic body may be stretched by a predetermined distance. Then, the compressed distance of the first elastic body can be measured using an infrared sensor, and the magnitude of the external force can be calculated by the Hooke's law on the measured compressed distance.

In the following, a controller including the series elastic actuator 600 described above will be described.

The controller according to one embodiment may include a series elastic actuator 600 and a PD controller.

The series elastic actuator 600 includes a power section 610 for providing power, an output section 620 spaced apart from the power section 610 by an external force at one side, a power section 610, And is connected to each of the power section 610 and the output section 620 in series and is displaced by the elasticity of at least one elastic body as an external force acts on the output section 620, And an elastic portion 625 for measuring the size. At this time, the power unit 610 generates a force corresponding to the value input from the PD controller, and can operate in a direction opposite to the direction of the force applied to the output unit 620. [ Here, the series elastic actuator 600 will be briefly described as a configuration and function of the series elastic actuator 600 described above, and a duplicate description will be omitted.

More specifically, the power section 610 is fixed to an end of the motor 611, the ball screw 612 driven by the motor 611, and the ball screw 612, As shown in FIG. Here, the ball screw 612 is driven by the motor 611 to adjust the height of the series elastic actuator 600.

The elastic portion 625 includes a first elastic body disposed on the upper side and a second elastic body disposed on the lower side with respect to the fixed plate 618 and is configured at both ends of the first elastic body to measure the magnitude of displacement due to elasticity And may further include an infrared sensor that measures the magnitude of the external force.

The power unit 610 drives the motor 611 as much as the height corresponding to the force feedback to move the fixing plate 618 through the ball screw 612 and thereby complies with the external force, Controller.

The PD controller receives the calculated external force acting on the output part 620 of the series elastic actuator 600 and calculates the difference between the calculated value and the value calculated in association with the encoder value, (610).

The above shows the design of the series elastic actuator manufactured directly based on the design. The spring can calculate the compression length when an external force equal to the target load is applied, and can produce the one that meets the desired specification. In addition, the displacement of the spring can be measured using an infrared sensor for force feedback.

Particularly, the series elastic actuator according to this embodiment can be applied to Segway or the like by canceling the force acting through the spring when the jaws or the like are crossed, thereby alleviating the impact. That is, the body can move due to an impact, but the foot plate can maintain its original state.

The apparatus described above may be implemented as a hardware component, a software component, and / or a combination of hardware components and software components. For example, the apparatus and components described in the embodiments may be implemented within a computer system, such as, for example, a processor, controller, arithmetic logic unit (ALU), digital signal processor, microcomputer, field programmable array (FPA) A programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions. The processing device may execute an operating system (OS) and one or more software applications running on the operating system. The processing device may also access, store, manipulate, process, and generate data in response to execution of the software. For ease of understanding, the processing apparatus may be described as being used singly, but those skilled in the art will recognize that the processing apparatus may have a plurality of processing elements and / As shown in FIG. For example, the processing apparatus may comprise a plurality of processors or one processor and one controller. Other processing configurations are also possible, such as a parallel processor.

The software may include a computer program, code, instructions, or a combination of one or more of the foregoing, and may be configured to configure the processing device to operate as desired or to process it collectively or collectively Device can be commanded. The software and / or data may be in the form of any type of machine, component, physical device, virtual equipment, computer storage media, or device As shown in FIG. The software may be distributed over a networked computer system and stored or executed in a distributed manner. The software and data may be stored on one or more computer readable recording media.

The method according to an embodiment may be implemented in the form of a program command that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions to be recorded on the medium may be those specially designed and configured for the embodiments or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. For example, it is to be understood that the techniques described may be performed in a different order than the described methods, and / or that components of the described systems, structures, devices, circuits, Lt; / RTI > or equivalents, even if it is replaced or replaced.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

Claims (15)

In a series elastic actuator,
A power section for providing power;
An output unit configured to be spaced apart from the power unit by a predetermined distance and having an external force acting on one side thereof; And
And an elastic portion disposed between the power portion and the output portion and connected in series with each of the power portion and the output portion and displaced by the elasticity of at least one elastic body as the external force acts on the output portion, ,
The power unit includes:
motor;
A ball screw driven by the motor to adjust the height of the series elastic actuator; And
And a fixing plate fixed to an end of the ball screw and moving up and down according to rotation of the ball screw,
The power unit is a compliance controller that drives the motor by a height corresponding to force feedback to cancel the external force by moving the fixing plate through the ball screw,
Wherein the elastic portion includes a first elastic body disposed on the upper side and a second elastic body disposed on the lower side with respect to the fixed plate,
Further comprising an infrared sensor configured to measure the magnitude of the external force by measuring a magnitude of displacement due to elasticity, the first and second elastic members being disposed at both ends of the first elastic body,
When the external force acts, the first elastic member disposed on the upper side of the fixing plate is compressed by a predetermined distance, and the second elastic member disposed on the lower end of the fixing plate is tensioned by a predetermined distance, Measuring the compressed distance using the infrared sensor and calculating the magnitude of the external force through the measured distance based on the Hooke's law
Wherein the elastic actuator comprises: delete delete delete The method according to claim 1,
The power unit includes:
The motor is driven by the height corresponding to the force feedback, and the external force is canceled by moving the fixing plate through the ball screw
Wherein the elastic actuator comprises: The method according to claim 1,
The power unit includes:
A first pulley connected to the ball screw; And
A second pulley connected to the motor and connected to the first pulley to transmit power of the motor,
Further comprising: an elastic actuator. The method according to claim 6,
The power unit includes:
The output portion, the elastic portion and the motor being connected in parallel by the first pulley and the second pulley
Wherein the elastic actuator comprises: The method according to claim 1,
The output unit includes:
A load plate having one side to which the external force acts;
A support plate spaced apart from the load plate by a predetermined distance; And
A plurality of support rods connecting the load plate and the support plate,
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Wherein the load plate and the support plate are disposed around the ball screw. 9. The method of claim 8,
The elastic portion
And two plates fixedly spaced apart from one another and connected to the plurality of support rods, wherein one of the two plates is fixed to the plurality of support rods including the support plate, and the other of the two plates Are movable relative to the plurality of support rods,
And a second elastic body disposed between the two plates, the first elastic body disposed on a load side that is an upper portion of the plurality of support bars with respect to the fixed plate, and the second elastic body disposed on a lower portion of the plurality of support rods
Wherein the elastic actuator comprises: 10. The method of claim 9,
Wherein the first elastic body and the second elastic body are made of a synthetic resin,
And two springs each formed on the outer circumferential surface of the plurality of support rods
Wherein the elastic actuator comprises: delete delete An output section that is spaced apart from the power section by a predetermined distance and has an external force acting on one side thereof; and an output section that is disposed between the power section and the output section and that is in series with each of the power section and the output section And an elastic portion that is connected to the output portion and is displaced by the elasticity of at least one elastic body as the external force acts on the output portion to measure the magnitude of the external force. And
A PD controller for receiving the calculated external force acting on the output part of the series elastic actuator and using the difference from the calculated value in association with the encoder value to provide the input of the power part of the series elastic actuator,
Lt; / RTI >
Wherein the power unit generates a force corresponding to an input value and operates in a direction opposite to a direction of a force applied to the output unit,
The power unit includes:
motor;
A ball screw driven by the motor to adjust the height of the series elastic actuator; And
And a fixing plate fixed to an end of the ball screw and moving up and down according to rotation of the ball screw,
The power unit is a compliance controller that drives the motor by a height corresponding to force feedback to cancel the external force by moving the fixing plate through the ball screw,
Wherein the elastic portion includes a first elastic body disposed on the upper side and a second elastic body disposed on the lower side with respect to the fixed plate,
Further comprising an infrared sensor configured to measure the magnitude of the external force by measuring a magnitude of displacement due to elasticity, the first and second elastic members being disposed at both ends of the first elastic body,
When the external force acts, the first elastic member disposed on the upper side of the fixing plate is compressed by a predetermined distance, and the second elastic member disposed on the lower end of the fixing plate is tensioned by a predetermined distance, Measuring the compressed distance using the infrared sensor and calculating the magnitude of the external force through the measured distance based on the Hooke's law
. delete delete

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