WO2020101053A1

WO2020101053A1 - Driving device having elastic member for connecting input and output

Info

Publication number: WO2020101053A1
Application number: PCT/KR2018/013835
Authority: WO
Inventors: 남형철; 최대성; 김병수
Original assignee: (주)로보티즈
Priority date: 2018-11-12
Filing date: 2018-11-13
Publication date: 2020-05-22
Also published as: KR102090446B1

Abstract

An embodiment of the present invention provides a driving device having an elastic member for connecting input and output. The driving device includes: a motor; a gear module connected to the motor; an elastic member which is provided in vicinity of the gear module, and receives power transferred from the gear module; an output unit which is connected to the elastic member and acts upon an external load; an input position feedback unit which is connected to the elastic member or the motor so as to avoid interference with the gear module; an output position feedback unit which is connected to the output unit and extends to the vicinity of the motor so as to avoid interference with the gear module; and a sensing module. The sensing module is provided in the vicinity of the motor so as to avoid interference with the gear module, and senses the deformation of each of the input position feedback unit and the output position feedback unit caused by the deformation of the elastic member when the output unit acts upon the load.

Description

Driving device with elastic member connecting input and output

The present invention relates to a driving device having an elastic member that connects an input and an output {DRIVING DEVICE HAVING ELASTIC MEMBER FOR CONNECTING INPUT AND OUTPUT}, and more specifically, an input capable of obtaining a torque value by measuring a deformation amount of an elastic member It relates to a driving device having an elastic member for connecting the output.

In recent years, the range of use has been widening not only for industrial use, but also for household robots and humanoid robots, and accordingly, robot technology is rapidly developing. In particular, in relation to robot technology, the actuator (driving device) mounted for the operation of the robot joint is one of the core parts of the robot, and among them, the reducer is used as the main configuration of the actuator, and typical examples are planetary gear reducers, harmonic reducers, and cycles. Lloyd's reducer. An actuator in which an elastic member is interposed between an input and an output is generally known as a series elastic actuator (SEA), which incorporates an elastic member (e.g., a spring) inside the actuator to deform the amount of elastic member against an external load. Refers to a device that can directly measure the torque of the actuator.

1 and 2 are views showing an example of a conventional series elastic actuator. 1 and 2, in order to measure the amount of deformation of the elastic member 50 with respect to the external load 70,

encoders

40 and 60 for measuring the amount of rotational deformation are generally used, and the elastic member 50 Each of the

encoders

40 and 60 is mounted before and after, to measure the amount of deformation of the elastic member 50 through a difference between the amount of deformation of the front and rear ends of the elastic member 50. However, as in the prior art, when two

encoders

40 and 60 are mounted before and after the elastic member 50, the wiring structure for connecting the

encoders

40 and 60 and the control device becomes very complicated, especially a rotating chain. In order to avoid the motor 10 and the reducer 30 and connect the

wirings

45 and 65, an additional space 3 (see Fig. 2) and a device is required, which causes an increase in the volume and weight of the entire actuator. do. In addition, as mounting of the

encoders

40 and 60 is difficult, it is necessary to disassemble all or part of the actuator for future maintenance, which causes an increase in maintenance cost. In addition, there is a possibility that lubricant used in the reduction unit or the output unit is introduced between the reduction unit and the output unit, which may have a fatal effect on the PCB of the

encoders

40 and 60, and in order to prevent this, the reduction unit and the spring Since a separate sealing must be provided between them, complexity and cost increase are caused. In addition, since the

wirings

45 and 65 must pass through the outside of the reduction gear, external noise may be directly affected. In addition, when a proximity distance measuring sensor is used, the

wirings

45 and 65 should be connected to the controller in the output direction, depending on the configuration. At this time, the output direction is a rotating part, and the controller is a fixed part. There is a problem that can cause twisting and disconnection of the wiring (45,65).

The technical problem to be achieved by the present invention is to provide a driving device having an elastic member that connects inputs and outputs, which is easy to measure the amount of deformation of the elastic member, has a simple structure, and is easy to maintain.

The technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by those skilled in the art from the following description. There will be.

In order to achieve the above technical problem, an embodiment of the present invention provides a driving device having an elastic member connecting an input and an output. The driving device includes a motor and a gear module connected to the motor; An elastic member provided near the gear module to receive power from the gear module; An output unit connected to the elastic member and acting on an external load; An input position feedback unit connected to the elastic member or the motor to avoid interference with the gear module; An output position feedback unit connected to the output unit and extended to the vicinity of the motor to avoid interference with the gear module; And includes a sensing module. The sensing module is provided in the vicinity of the motor to avoid interference with the gear module, each of the input position feedback unit and the output position feedback unit due to deformation of the elastic member when the load is applied to the output unit Deformation is detected.

In an embodiment of the present invention, the sensing module, the motor, the gear module, the elastic member and the output unit are located in order, the sensing module, the input terminal of the elastic member from the input position feedback unit or the motor A first encoder that detects a rotation angle; And a second encoder that detects a rotation angle of the output unit from the output position feedback unit.

In an exemplary embodiment of the present invention, a control unit configured to obtain torque applied to the load based on a difference between the rotation angles by receiving a feedback from the first encoder and a rotation angle from the second encoder; It may further include.

In an embodiment of the present invention, the input position feedback part is connected to the input end of the elastic member, the input position feedback part and the output position feedback part penetrates through the rotation axis of the gear module and the motor, to the rear of the motor. Extended, the first encoder is coupled to the input position feedback unit extending to the rear of the motor, the second encoder may be coupled to the output position feedback unit extending to the rear of the motor.

In an embodiment of the present invention, the input position feedback part is connected to the motor from the rear of the motor, and the output position feedback part penetrates through the gear module and the rotation shaft of the motor and extends to the rear of the motor, A first encoder may be coupled to the input position feedback section at the rear of the motor, and the second encoder may be coupled to the output position feedback section extending to the rear of the motor.

In an embodiment of the present invention, an increase gear train provided between the elastic member and the output unit; as, by increasing the rotation angle of the output unit, the rotation angle difference between the input position feedback unit and the output position feedback unit It may further include; increasing gear train.

In an embodiment of the present invention, the first encoder and the second encoder may be one selected from an absolute encoder and an incremental encoder.

In an embodiment of the present invention, the control unit is provided with the detection module at the rear, it may be blocked with the lubricant of the gear module.

In an embodiment of the present invention, at least one of the input position feedback part and the output position feedback part has a hollow structure so that one of the input position feedback part and the output position feedback part penetrates the inside of the other. Can be.

In an embodiment of the present invention, the output position feedback unit passes through the gear module and the rotation shaft of the motor, extends to the rear of the motor, and a motor feedback unit connected to the motor from the rear of the motor; And a third encoder coupled to the motor feedback unit at the rear of the motor; may further include a.

According to an embodiment of the present invention, it is possible to provide a driving device having an elastic member that connects an input and an output, which avoids interference of a gear module or the like, has a compact structure, and is easy to measure a deformation amount of the elastic member.

It should be understood that the effects of the present invention are not limited to the above-described effects, and include all effects that can be deduced from the configuration of the invention described in the detailed description or claims of the present invention.

1 and 2 are views showing an example of a conventional series elastic actuator.

Figure 3 (a) is a block diagram showing a drive device having an elastic member for connecting the input and output according to an embodiment of the present invention.

Figure 3 (b) is a block diagram showing a drive device having an elastic member for connecting the input and output according to another embodiment of the present invention.

4 is a view showing an example of a drive device having an elastic member connecting the input and output shown in Figure 3 (a).

5 is a view for explaining a method of measuring a deformation amount and a torque of an elastic member in a driving device having an elastic member connecting an input and an output according to an embodiment of the present invention.

6 is a view showing an example of an elastic member.

7 is a view showing an example of a drive device having an elastic member connecting the input and output shown in Figure 3 (b).

8 (a) is a block diagram showing a driving device having an elastic member connecting an input and an output according to another embodiment of the present invention.

8 (b) is a block diagram showing a driving device having an elastic member connecting an input and an output according to another embodiment of the present invention.

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention may be implemented in various different forms, and thus is not limited to the embodiments described herein. In addition, in order to clearly describe the present invention in the drawings, parts irrelevant to the description are omitted, and like reference numerals are assigned to similar parts throughout the specification.

Throughout the specification, when a part is "connected (connected, contacted, coupled)" with another part, it is not only "directly connected" but also "indirectly connected" with another member in between. "It also includes the case where it is. Also, when a part “includes” a certain component, this means that other components may be further provided instead of excluding other components, unless otherwise stated.

The terms used herein are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “include” or “have” are intended to indicate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, and that one or more other features are present. It should be understood that the existence or addition possibilities of fields or numbers, steps, operations, components, parts or combinations thereof are not excluded in advance.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 3 (a) is a block diagram showing a drive device having an elastic member 350 for connecting the input and output according to an embodiment of the present invention. 4 is a view showing an example of a drive device having an elastic member 350 connecting the input and output shown in Figure 3 (a).

A driving device (hereinafter, a driving device) having an elastic member 350 connecting inputs and outputs includes a motor 310, a gear module 330, an elastic member 350, an output unit 370, and an input position feedback unit ( 410), an output position feedback unit 430, and a sensing module. The gear module 330 (eg, a reduction gear module) may be coupled to the front end of the motor 310. The elastic member 350 is provided in the vicinity of the gear module 330, receives power from the gear module 330. The elastic member 350 may be a spring, as shown in FIG. 1, or may be a spring of another type. For example, the elastic member 350 may be a substantially circular elastic body (see FIG. 6). The shape or structure of the elastic member 350 can be variously modified. In addition, the elastic member 350 may be formed of a metal material, but may also be formed of a material other than metal (eg, rubber or plastic).

The output unit 370 may be connected to the rear end and the output end of the elastic member 350, and may act on or combine with an external load to transmit power. The input position feedback unit 410 has rigidity and is connected to the elastic member 350 or the motor 310 to avoid interference with the gear module 330. In this embodiment, the input position feedback unit 410 may be connected to the front end of the elastic member 350, that is, the input end. The output position feedback unit 430 has rigidity and is connected to the output unit 370 and may be extended to the vicinity of the motor 310 to avoid interference with the gear module 330. The sensing module may be provided in the vicinity of the motor 310 to avoid interference with the gear module 330. The sensing module may detect deformation of each of the input position feedback unit 410 and the output position feedback unit 430 due to deformation of the elastic member 350 when the output unit 370 acts on the load.

In this embodiment, the sensing module, the motor 310, the gear module 330, the elastic member 350 and the output unit 370 may be located in order, they may be accommodated in the housing 302. The sensing module may include a first encoder 340 (encoder) and a second encoder (360). The first encoder 340 may detect the input terminal of the elastic member 350 or the rotation angle of the motor 310 from the input position feedback unit 410, and in the present embodiment, the first encoder 340 is an elastic member ( The rotation angle of the input terminal of 350) can be detected. The second encoder 360 may detect the rotation angle of the output unit 370 from the output position feedback unit 430.

In this embodiment, as described above, the input position feedback unit 410 is connected to the input end of the elastic member 350, and the input position feedback unit 410 and the output position feedback unit 430 are gear modules 330. ) And through the rotating shaft 320 of the motor 310, it may extend to the rear of the motor 310. At least one of the input position feedback unit 410 and the output position feedback unit 430 has a hollow structure so that one of the input position feedback unit 410 and the output position feedback unit 430 penetrates the inside of the other. Can have In this embodiment, both the output position feedback unit 430 and the input position feedback unit 410 have a hollow shaft shape, and the output position feedback unit 430 is configured to penetrate into the input position feedback unit 410. Can be. The shapes of the input position feedback unit 410 and the output position feedback unit 430 are not necessarily limited to a hollow shaft, that is, a cylindrical shape, and the rotation angle of the output unit 370 (ie, the rear end of the elastic member 350) It is preferable to have a rigidity that can reflect the rotation angle of the front end of the elastic member 350 and the elastic member 350 as it is. If it is such a member, the input position feedback unit 410 and the output position feedback unit 430 The shape of) may be variously modified, such as a simple bar, a part of a cylindrical shape, and a cylindrical shape. In addition, although the example shown in FIG. 4 illustrates the case where the input position feedback unit 410 and the output position feedback unit 430 are linear, differently, it may have a structure that is bent and extended backward as necessary. In the example shown in FIG. 4, the input position feedback unit 410 includes an input terminal coupling unit 411 coupled to the input terminal of the elastic member 350 and an extension cylinder portion 413 extending rearward from the input terminal coupling unit 411. It can contain. Likewise, the output position feedback unit 430 extends rearward from the output coupling unit 431 coupled to the output unit 370, and the output coupling unit 431, and extends the cylinder 413 of the input position feedback unit 410. ) May include an extension portion 433 passing therethrough.

The first encoder 340 is coupled to the extension cylinder portion 413 of the input position feedback unit 410 extending rearward of the motor 310, and the second encoder 360 outputs rearward of the motor 310 It may be coupled to the extension portion 433 of the position feedback unit 430.

5 is a view for explaining a method of measuring the amount of deformation and torque of the elastic member 350 in the driving device having the elastic member 350 connecting the input and the output according to an embodiment of the present invention. 6 is a view showing an example of the elastic member 350.

The driving device (eg, the series elastic actuator) may further include a control unit 305. The control unit 305 receives the rotation angle from the first encoder 340 and the rotation angle from the second encoder 360 from the detection module, and receives torque applied to the load based on a difference between the rotation angles. Can be obtained. The control unit 305 is provided at the rear of the detection module, it may be provided to be blocked from the lubricant of the gear module 330. The first encoder 340 and the second encoder 360 may be one selected from an absolute encoder and an incremental encoder, and any of them may be used.

The gear module 330 may be coupled to the input end of the elastic member 350. For example, the input terminal coupling portion 411 of the input position feedback portion 410 may be interposed between the input terminal of the gear module 330 and the elastic member 350, the gear module 330, the input terminal coupling portion 411 ) And the input end of the elastic member 350 may be rotated together. Accordingly, the extension cylinder portion 413 of the input position feedback portion 410 may be rotated so that the rotation to the rotation angle D1 of the input end of the elastic member 350 is reflected. The power transmitted from the gear module 330 to the elastic member 350 may be transmitted to the output unit 370 coupled to the output end of the elastic member 350. The output unit 370 is coupled to the output coupling unit 431 of the output position feedback unit 430, so that the extension portion 433 of the output position feedback unit 430 is rotated or rotated by the output unit 370 ( It can be rotated to reflect D2). An external load may be connected to the output unit 370. Accordingly, the elastic member 350 may be deformed due to the load, and the first (eg, before the load is applied) of the elastic member 350 between the input end and the output end of the elastic member 350 The angle of can be changed. The first encoder 340 may detect the rotation angle of the input end of the elastic member 350 from the reference point from the rotation of the extension cylinder 413 of the input position feedback unit 410. The second encoder 360 may detect the rotation angle of the output end of the elastic member 350 from the reference point from the rotation of the extension portion 433 of the output position feedback unit 430. The control unit 305 receives feedback of the rotation angle detected by the first encoder 340 and the rotation angle detected by the second encoder 360, and uses the difference D12 (see FIG. 5) to determine the current elastic member ( The torque applied to 350) can be calculated or obtained. That is, the torque from the output unit 370 applied to the load can be obtained.

According to this embodiment, instead of having an encoder directly at the input end and the output end of the elastic member 350, as described above, the position of the input end and the output end is received through the inner passage substantially passing through the rotation shaft 320. Therefore, the interference between the gear module 330 and the encoder can be fundamentally blocked, and in particular, there is no need to provide a separate space inside the side of the driving device in order to withdraw the wiring from the encoder to the control unit 305, so that the structure is It becomes compact and concise. In addition, twisting, disconnection, and external noise interference of the wiring may be basically eliminated. In addition, by-products such as lubricants of the gear module 330 can also be removed by causing the encoder or the controller 305 to be contaminated and damaged.

Figure 3 (b) is a block diagram showing a drive device having an elastic member 350 for connecting the input and output according to another embodiment of the present invention. 7 is a view showing an example of a drive device having an elastic member 350 connecting the input and output shown in Figure 3 (b).

3 (b) and 7, except that the first encoder 340 is not the input terminal of the elastic member 350, but is directly connected to the output of the motor 310, the driving device shown in FIG. And since it is substantially the same as the driving device described in FIG. 4, redundant description is omitted. In the driving device, the input position feedback unit 410 may be coupled to the motor 310 at the rear of the motor 310, that is, to the rotation shaft 320 of the motor 310. Therefore, the input position feedback unit 410 may feedback the output position of the motor 310. The first encoder 340 may be coupled to the input position feedback unit 410 at the rear of the motor 310. The output position feedback unit 430 penetrates through the rotation axis 320 of the gear module 330 and the motor 310, and extends to the rear of the motor 310, and the second encoder 360 is the rear of the motor 310 It can be coupled to the extended portion 433 of the output position feedback unit 430 extended.

In this embodiment, since the first encoder 340 is installed before the input end of the elastic member 350 or before the output side of the gear module 330, it is more controlled than the embodiments shown in FIGS. 3 (a) and 4. You can choose according to your needs.

8 (a) is a block diagram showing a driving device having an elastic member 350 connecting an input and an output according to another embodiment of the present invention.

The driving device illustrated in FIG. 8 (a) is substantially the same as the driving device illustrated in FIGS. 3 (a) and 4, except that the drive gear 390 is further increased, and thus duplicate description is omitted. do. The increased gear train 390 may be provided between the elastic member 350 and the output unit 370. The elastic member 350 may vary depending on the elastic modulus, but when the deformation amount of the elastic member 350 is relatively small when a load is applied to the output unit 370, a high-performance to high-resolution expensive encoder is used to detect the deformation amount. There may be a burden to use. In the present exemplary embodiment, the speed increasing gear train 390 may increase the rotation or rotation angle of the output unit 370. Therefore, the difference between the rotation angle of the input end of the elastic member 350 detected by the first encoder 340 and the rotation angle of the output end of the elastic member 350 detected by the second encoder 360 (deformation amount of the elastic member) Can be amplified. Therefore, even if a relatively low-resolution encoder is used, the deformation amount can be sufficiently detected. Therefore, it is possible to obtain a deformation amount or a torque value with high precision using a low-cost to low-resolution encoder.

8 (b) is a block diagram showing a driving device having an elastic member 350 connecting an input and an output according to another embodiment of the present invention.

The driving device illustrated in FIG. 8 (b) is the driving described in FIGS. 3 (a) and 4, except that it further includes a motor feedback unit (eg, 410 in FIG. 7) and a third encoder 380. Since it is substantially the same as the device, a duplicate description is omitted. In the driving device, the output position feedback unit 430 may extend through the gear module 330 and the rotating shaft 320 of the motor 310 to the rear of the motor 310. The motor feedback unit may be connected to the motor 310 from the rear of the motor 310 to feed back the motor 310 output. The third encoder 380 is coupled to the motor feedback unit at the rear of the motor 310, so that the position of the output of the motor 310 can be fed back to the control unit 305.

As described above, according to the present embodiment, the encoders are installed at the rear of the motor 310, and the rotation angle of the elastic member 350 through the extension cylinder part 413 and the extension part 433 passing through the rotation shaft 320 is determined. Get feedback. Therefore, it is structurally simple and easy to assemble, so that it is very easy to mount an additional encoder, such as a third encoder, or to remove the encoder for maintenance, if necessary.

The above description of the present invention is for illustration only, and those skilled in the art to which the present invention pertains can understand that the present invention can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is indicated by the following claims, and all modifications or variations derived from the meaning and scope of the claims and their equivalent concepts should be interpreted to be included in the scope of the present invention.

Forms for carrying out the invention have been described together in the best mode for carrying out the invention above.

Claims

In the drive device having an elastic member for connecting the input and output,

motor;

A gear module connected to the motor;

An elastic member provided near the gear module to receive power from the gear module;

An output unit connected to the elastic member and acting on an external load;

An input position feedback unit connected to the elastic member or the motor to avoid interference with the gear module;

An output position feedback unit connected to the output unit and extended to the vicinity of the motor to avoid interference with the gear module; And

It is provided in the vicinity of the motor to avoid interference with the gear module, the deformation of each of the input position feedback unit and the output position feedback unit due to deformation of the elastic member when the output unit acts on the load (deformation) A sensing device for sensing; A driving device having an elastic member for connecting the input and output, characterized in that it comprises a.
According to claim 1,

Located in the order of the detection module, the motor, the gear module, the elastic member and the output unit,

The detection module,

A first encoder that detects an input end of the elastic member or a rotation angle of a motor from the input position feedback unit; And

And a second encoder that detects a rotation angle of the output unit from the output position feedback unit.
According to claim 2,

Further comprising a control unit for obtaining a torque applied to the load on the basis of the difference (difference) between the rotation angle from the rotation angle from the first encoder and the rotation angle from the second encoder, characterized in that it further comprises a A driving device having an elastic member connecting the input and output.
According to claim 2,

The input position feedback part is connected to the input end of the elastic member,

The input position feedback unit and the output position feedback unit penetrates through the rotation axis of the gear module and the motor, and extends to the rear of the motor,

The first encoder is coupled to the input position feedback part extending rearward of the motor,

The second encoder is a drive device having an elastic member for connecting the input and output, characterized in that coupled to the output position feedback unit extending to the rear of the motor.
According to claim 2,

The input position feedback unit is connected to the motor from the rear of the motor,

The output position feedback part penetrates through the rotation axis of the gear module and the motor, and extends to the rear of the motor,

The first encoder is coupled to the input position feedback unit at the rear of the motor,

The second encoder is a drive device having an elastic member for connecting the input and output, characterized in that coupled to the output position feedback unit extending to the rear of the motor.
According to claim 2,

An incremental gear train provided between the elastic member and the output unit; an increase gear train increasing the rotation angle of the output unit to increase a difference in rotation angle between the input position feedback unit and the output position feedback unit; The drive device having an elastic member for connecting the input and output, characterized in that it further comprises.
According to claim 2,

The first encoder and the second encoder are a drive device having an elastic member for connecting the input and output, characterized in that one selected from an absolute encoder (absolute encoder) and an incremental encoder (incremental encoder).
According to claim 3,

The control unit is a driving device having an elastic member for connecting the input and output, characterized in that the detection module is provided at the rear, and is blocked from the lubricant of the gear module.
According to claim 4,

At least one of the input position feedback part and the output position feedback part has a hollow structure so that one of the input position feedback part and the output position feedback part penetrates the inside of the other. Driving device having an elastic member to connect.
According to claim 4,

The output position feedback part penetrates through the rotation axis of the gear module and the motor, and extends to the rear of the motor,

A motor feedback part connected to the motor from the rear of the motor; And

And a third encoder coupled to the motor feedback part at the rear of the motor.