KR102551645B1 - Method for controlling folding link - Google Patents

Abstract

A control method of a foldable link according to an embodiment of the present invention is a deployment control method for deploying a foldable link, comprising: fixing a position of a wire connected to the foldable link; determining whether a deployment command is received; is received, applying air pressure to the inside of the foldable link, releasing the tension of the wire to increase the length of the wire, determining whether the foldable link is fully deployed, and the unfolding is completed. In this case, applying tension to the wire may be included.

Description

Control method of folding link {METHOD FOR CONTROLLING FOLDING LINK}

The present invention relates to a method for controlling a folding link.

Recently, the robot market tends to change from industrial robots that were used by putting up fences in factories to cooperative robots with safety standards that can work together with humans and are smaller in size and can interact with each other. However, even if it is possible to work with a human, since it is a robot made of a rigid body, there are fundamental limitations with respect to spatial limitations or sudden shocks.

Collaborative robots are robot arms that can physically interact with humans and perform tasks in cooperation with each other. For example, collaborative robots can perform tasks such as assisting factory workers in the assembly process and cooperating with humans in the kitchen to cook.

So far, cooperative work between humans and robots has been considered only in factories, but recently, as robots enter everyday life, new types of service robots are being developed. For example, a domestic company announced a robot arm that cooks in collaboration with people in the kitchen.

Current collaborative robots have limitations in installation space, and when interacting with a large number of people in an irregular space, the work range is fixed, limiting the types of tasks that can be performed. In addition, rigid body-based robot arms and grippers have limitations in practical use due to the risk of collision.

Accordingly, in order to solve these problems, the academic world is actively researching soft robot technology and foldable robot technology capable of designing with high inherent safety and large deformation.

Soft robot technology is a new type of technology that can interact with an atypical environment by using flexible materials. For example, a universal gripper that can grip objects regardless of their shape, soft robots that can safely exchange power with people because they are soft. arms, etc.

Folding soft robotic arm technology is a new robotic arm manufacturing and control technology that can change shape and stiffness by utilizing flexible materials, deployable origami structures, and wire/pneumatic actuation.

However, these soft robot technologies and foldable robot technologies still have low control precision, making them difficult to apply to daily life.

An embodiment of the present invention is designed and driven using soft robot technology with intrinsic safety to solve the safety problem of rigid robots, and works efficiently even within a limited space through shape change using foldable structures and wires. It is intended to provide a control method of a foldable link capable of realizing a robot arm with stability and stability.

A control method of a foldable link according to an embodiment of the present invention is a deployment control method for deploying a foldable link, comprising: fixing a position of a wire connected to the foldable link; determining whether a deployment command is received; is received, applying air pressure to the inside of the foldable link, releasing the tension of the wire to increase the length of the wire, determining whether the foldable link is fully deployed, and the unfolding is completed. In this case, applying tension to the wire may be included.

The collapsible link is formed in an origami method, so that it can be deformed to be folded or unfolded, and an internal space can be formed.

In the step of increasing the length of the wire, the speed at which the foldable link is deployed may be adjusted by driving the control mode of the actuator to the position control mode and controlling the speed at which the length of the wire is increased.

In the step of determining whether the unfolding is completed, it may be determined that the unfolding is completed when the length of the wire is greater than or equal to a first set length, and it may be determined that the unfolding is incomplete when the length of the wire is less than the first set length.

A control method of a foldable link according to an embodiment of the present invention is a folding control method for folding a foldable link, comprising the steps of determining whether a folding command is received, and when receiving a folding command, air inside the foldable link. discharging, applying tension to the wire to reduce the length of the wire connected to the foldable link, determining whether the length of the foldable link is less than or equal to a predetermined length, and determining whether the length of the foldable link is equal to or less than the predetermined length In the following cases, the step of applying a tension impact to the wire, the step of determining whether the folding of the foldable link is complete, the step of applying tension to the wire when the folding is complete, and the step of fixing the position of the wire. can include

The collapsible link is formed in an origami method, so that it can be deformed to be folded or unfolded, and an internal space can be formed.

The step of applying tension to the wire to reduce the length of the wire connected to the foldable link, driving the control mode of the actuator in the current control mode, by controlling the speed of increasing the length of the wire through the current control of the actuator , It is possible to adjust the folding speed of the foldable link.

In the step of determining whether the length of the foldable link is less than or equal to a predetermined length, when the length of the wire is less than or equal to a second set length, it is determined that the length of the foldable link is less than or equal to a predetermined length, and the length of the wire is equal to or less than a second set length. If it exceeds, it can be determined that the length of the foldable link exceeds a predetermined length.

In the step of applying the tension impact to the wire, a tension impact pulse may be generated by repeating a process of applying a maximum tension to the wire for a predetermined time and then removing the tension for a predetermined time.

In the step of determining whether the folding is completed, it may be determined that the folding is completed when the length of the wire is less than or equal to the third set length, and the folding is incomplete when the length of the wire is greater than the third set length. .

A control method of a foldable link according to an embodiment of the present invention is designed and driven using soft robot technology having intrinsic safety, and can efficiently work even within a limited space through a shape change using a foldable structure and wire. possible and secure.

The control method of a foldable link according to an embodiment of the present invention can secure safety in interaction with people while maintaining constant performance, and can increase the possibility of application to various tasks through modularization.

In the control method of the foldable link according to an embodiment of the present invention, since the length and stiffness of the foldable link can be changed, it can be used for work such as kitchen assistant, nursing assistant, and housekeeping assistant in everyday spaces such as restaurants, hospitals, and homes. It can be applied to various fields that require variable soft robots such as industrial robot arms, devices for invasive surgery, and wearable robots.

1 is a perspective view of a foldable structure in which a foldable link according to an embodiment of the present invention is deployed.
2 is a flowchart of a control method for deploying a collapsible link according to an embodiment of the present invention.
3 is a flowchart of a control method for folding a collapsible link according to an embodiment of the present invention.
4 is a perspective view of a foldable structure in which buckling occurs in a folding process of a foldable link according to an embodiment of the present invention.
5 is a graph showing the impact of tensile force applied to a wire according to an embodiment of the present invention.
6 is a perspective view showing a collapsible structure in which a collapsible link is folded according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. This invention may be embodied in many different forms and is not limited to the embodiments set forth herein. In order to clearly describe the present invention in the drawings, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification.

In this specification, terms such as "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that it does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof.

1 is a perspective view of a foldable structure in which a foldable link is deployed according to an embodiment of the present invention, and FIG. 2 is a flowchart of a control method for deploying a foldable link according to an embodiment of the present invention.

A foldable structure 1 according to an embodiment of the present invention will be described with reference to FIG. 1 .

Referring to FIG. 1 , the foldable structure 1 may include a frame portion 10, a foldable link 20, a wire 30, and an actuator 40.

The frame unit 10 may be connected to the foldable link 20 to support the foldable link 20 . Specifically, the frame unit 10 may include a lower frame 10a and an upper frame 10b. The lower frame 10a may be coupled to the lower portion of the foldable link 20 and the upper frame 10b may be coupled to the upper portion of the foldable link 20 . For example, the lower frame 10a and the upper frame 10b may be installed with three foldable links 20 spaced apart from each other based on the center.

The collapsible link 20 is formed in an origami manner and can be deformed to be folded or unfolded, and an internal space can be formed. For example, as shown in FIG. 1 , the collapsible link 20 may have a tubular shape having a predetermined height when air is introduced into the internal space and deployed. In addition, the foldable link 20 may be formed with a plurality of fold lines 21, and as the fold lines 21 are folded or unfolded, the foldable link 20 may be deformed.

The wire 30 may be coupled to the collapsible link 20 . At this time, one end of the wire 30 may be connected to the actuator 40 installed on the lower frame 10a and the other end may be connected to the upper frame 10b. At this time, the tension and length of the wire 30 may be adjusted by an actuator.

The actuator 40 may be installed on the frame unit 10 to control driving of the wire 30 . Specifically, the actuator 40 may be installed on the lower frame 10a. As another example, the number of actuators 40 corresponding to the number of foldable links 20 may be installed.

As another example, the actuator 40 may be a DC motor. At this time, the actuator 40 may adjust the tension and length of the wire 30 by rotating the pulley so that the wire 30 is wound or unwound around the pulley.

For example, when tension is applied to the wire 30 through the actuator 40, the length of the wire 30 may be reduced or the wire 30 may be tightly fixed, and the tension applied to the wire 30 When reducing or releasing the length of the wire 30 may increase.

At this time, as the length of the wire 30 is adjusted, the position of the upper frame 10b is changed so that the folding link 20 can be deployed or folded, and when the wire 30 is fixed, the position of the upper frame 10b is changed. While being fixed, the collapsible link 20 can also maintain a constant state.

In addition, a sensor unit (not shown) may be further installed in the actuator 40 . The sensor unit may generate a pulse output as the shaft of the actuator 40 rotates, and measure the amount of change in the length of the wire 30 .

Meanwhile, as a controller of the foldable link, a lower controller and a higher controller may be included. The lower controller may control driving of the actuator 40 . For example, the lower controller can be a DC motor driver.

The upper controller may transmit commands to the lower controller. Accordingly, the lower controller can control the operation of the actuator 40 according to the command of the upper controller. In addition, the host controller may calculate the length of the wire 30 by receiving the length variation data measured by the sensor unit.

In addition, the upper controller transmits a position control command or a current control command to the lower controller, and accordingly, the lower controller sets the control mode of the actuator 40 to the position control mode or the current control mode, so that the actuator 40 operates according to the set mode. can drive As the mode change command is transmitted from the upper controller to the lower controller, the control mode of the actuator 40 can be switched between the position control mode and the current control mode.

In the position control mode, the actuator 40 can be moved to a desired position by adjusting the current of the actuator 40 . For example, as the shaft of the actuator 40 is rotated, the rotational position of the shaft may converge to a desired position. In addition, the position control mode allows the wire 30 to converge to a desired position.

In the current control mode, a desired current may be applied to the actuator 40 . At this time, the current control mode can control the torque of the actuator 40 shaft by controlling the current applied to the actuator 40 . That is, as the current of the actuator 40 is controlled, the torque of the shaft of the actuator 40 is maintained constant or can be varied. In addition, the tension of the wire 30 can be adjusted in the current control mode.

Referring to FIG. 2, a deployment control method for deploying the foldable link 20 according to an embodiment of the present invention will be described.

The deployment control method includes fixing the position of the wire (S110), determining whether a deployment command is received (S120), applying air pressure (S130), increasing the length of the wire (S140), folding It may include determining whether the link development is completed (S150) and applying tension to the wire (S160).

First, the position of the wire connected to the foldable link may be fixed (S110). Specifically, by applying tension to the wire 30 by operating the actuator 40, the length of the wire 30 may be maintained at a constant position without being changed. Accordingly, even when an external force acts on the foldable link 20 by fixing the position of the wire 30, it is possible to keep the foldable link 20 unchanged.

Thereafter, it may be determined whether or not a deployment command has been received (S120). Specifically, when the host controller receives the unfolding command, it may perform the next step, and when it does not receive the unfolding command, it may return to the aforementioned step of fixing the position of the wire (S110).

Thereafter, when receiving a deployment command, air pressure may be applied to the inside of the collapsible link (S130). Specifically, by introducing air into the inner space of the foldable link 20, the foldable link 20 can be prepared to be deployed by air pressure.

Thereafter, the length of the wire may be increased by releasing the tension of the wire (S140). Specifically, the upper controller may transmit a position control command to the lower controller, and the lower controller may drive the control mode of the actuator 40 to the position control mode. That is, by the position control mode, the actuator 40 can move the axis to a preset position. Accordingly, the actuator 40 may increase the length of the wire 30 by unwinding the wire 30, and at the same time, the folding link 20 may be deployed by air pressure.

At this time, the length and length increasing speed of the wire 30 are controlled by restricting the position of the actuator 40 due to the position control mode, and thus the length and unfolding speed of the foldable link 20 can be controlled.

Thereafter, it may be determined whether deployment of the foldable link is completed (S150). Specifically, when the length of the wire 30 is greater than or equal to the first set length, it is determined that the unfolding is completed, and when the length of the wire 30 is less than the first set length, it is determined that the unfolding is incomplete. For example, the sensor unit installed in the actuator 40 may measure the amount of change in the length of the wire 30, through which the upper controller may calculate the length of the wire 30.

Accordingly, when it is determined that the unfolding is completed, the next step may be performed, and when it is determined that the unfolding is incomplete, the aforementioned step of increasing the length of the wire may be returned (S140).

On the other hand, when the first set length is set to the maximum value, as shown in FIG. 1, the foldable link 20 can be fully deployed.

Thereafter, when the unfolding is completed, tension may be applied to the wire (S160). Specifically, by applying tension to the wire 30 through the actuator 40 after the unfolding of the foldable link 20 is completed, it is possible to prevent the wire 30 from sagging. Accordingly, the wire 30 maintains a taut state by the applied tension, and at the same time, the foldable link 20 can maintain a state inflated by air pressure, so that the shape of the foldable link 20 can be kept constant. there is.

3 is a flowchart of a control method for folding a foldable link according to an embodiment of the present invention, and FIG. 4 is a perspective view of a foldable structure in which buckling occurs in the folding process of a foldable link according to an embodiment of the present invention. 5 is a graph showing the impact of tension applied to the wire according to an embodiment of the present invention, and FIG. 6 is a perspective view showing a foldable structure in which a foldable link according to an embodiment of the present invention is folded.

Referring to FIG. 3, a folding control method for folding the folding link 20 according to an embodiment of the present invention will be described.

The folding control method includes determining whether a folding command is received (S210), discharging air inside the foldable link (S220), reducing the length of the wire (S230), and the length of the foldable link is a predetermined length. or less (S240), applying a tensile impact to the wire (S250), determining whether the folding is complete (S260), applying tension to the wire (S270), and positioning the wire It may include fixing (S280).

According to the aforementioned deployment control method, the foldable link 20 is deployed by air pressure, and tension is applied to the wire 30 . At this time, the tension of the wire can be maintained at a level at which buckling does not occur in the foldable link 20 .

First, it may be determined whether or not a folding command is received (S210). Specifically, when the upper controller receives the folding command, the next step may be performed, and when the folding command is not received, the air pressure and tension may be constantly maintained.

Thereafter, when a folding command is received, air inside the folding link may be discharged (S220). Specifically, the air existing in the inner space of the folding link 20 may be discharged to the outside by opening the pneumatic valve (not shown), and accordingly, the folding link 20 may be prepared to be folded by reducing the air pressure. can

Then, tension may be applied to the wire to reduce the length of the wire connected to the foldable link (S230). Specifically, the upper controller may transmit a current control command to the lower controller, and the lower controller may drive the actuator 40 in the current control mode. That is, in the current control mode, the actuator 40 may apply tension to the wire 30 by rotating the shaft according to the applied current. Accordingly, the actuator 40 may reduce the length of the wire 30 by winding the wire 30, and at the same time, the folding link 20 may be folded by a decrease in air pressure.

At this time, the actuator 40 driven in the current control mode can minimize a buckling phenomenon that may occur when the foldable link 20 is forcibly folded by applying a constant tension to the wire 30 . Specifically, when using the current control mode, the torque of the actuator 40 shaft is controlled in response to the speed at which air is discharged from the folding link 20, and the speed at which the wire 30 is pulled is controlled accordingly, thereby minimizing buckling. can do. For example, the pulling speed of the wire 30 may increase when the air discharge speed is high, and the pulling speed of the wire 30 may decrease when the air discharge speed is low. That is, the current control mode allows the air to be sufficiently discharged from the foldable link 20 and at the same time adjusts the pulling speed of the wire 30 according to the air discharge speed, so that the foldable link 20 can be easily folded.

In addition, the length and length reduction speed of the wire 30 are controlled by sensing the length of the wire 30 and controlling the current of the actuator 40 due to the current control mode, and thus the length and folding of the folding link 20 Speed can be controlled.

Then, it is possible to determine whether the length of the foldable link is equal to or less than a predetermined length (240). Referring to FIG. 4, the predetermined length (L1) is at the time when the folding link 20 is not folded even when a buckling phenomenon occurs in some folding lines 21 of the folding link 20 and tension is applied to the wire 30 It is the length of the folding link 20. This predetermined length (L1) can be set through an experiment to observe the buckling phenomenon in the unfolding and folding process of the foldable link (20).

At this time, whether or not the length (X) of the foldable link is less than or equal to the predetermined length (L1) can be determined through the length of the wire (30). Specifically, when the length of the wire 30 is equal to or less than the second set length, it is determined that the length (X) of the foldable link 20 is equal to or less than the predetermined length (L1), and the length of the wire 30 exceeds the second set length. In this case, it can be determined that the length (X) of the foldable link 20 exceeds the predetermined length (L1). For example, the sensor unit installed in the actuator 40 may measure the amount of change in the length of the wire 30, through which the upper controller may calculate the length of the wire 30.

Accordingly, when it is determined that the length (X) of the foldable link is less than the predetermined length (L1), the next step may be performed, and when it is determined that the length (X) of the foldable link is greater than the predetermined length (L1), the above-described wire It is possible to return to step S230 of reducing the length of .

Thereafter, when the length of the foldable link is less than a predetermined length, a tensile impact may be applied to the wire (S250). Specifically, by applying a tension impact pulse to the wire 30, it can be induced to be folded in the designed direction of the fold line 21, which is not partially folded, of the foldable link 20. For example, the frequency of the tension impact pulse may be 300 Hz.

Also, the magnitude of the tension impact may be the maximum output of the actuator 40 . At this time, a tension impact pulse may be generated by repeating a process of applying maximum tension to the wire 30 for a predetermined time and then removing the tension for a predetermined time. For example, as shown in FIG. 5, after applying the maximum tension to the wire 30 for 100 ms (millisecond), and then removing the power of the actuator 40 for the next 100 ms, the process of removing the tension is repeated. Tension impact pulses can be generated. At this time, since the air pressure of the foldable link 20 is reduced and the length of the wire 30 is reduced, the foldable link 20 can be continuously folded.

Thereafter, it may be determined whether the folding of the collapsible link is completed (S260). Specifically, when the length of the wire 30 is equal to or less than the third set length, it is determined that the folding is complete, and when the length of the wire 30 is greater than the third set length, it is determined that the folding is incomplete. For example, the sensor unit installed in the actuator 40 may measure the amount of change in the length of the wire 30, through which the upper controller may calculate the length of the wire 30.

Accordingly, when it is determined that the folding is completed, the next step may be performed, and when it is determined that the folding is incomplete, the above-described step of applying a tensile impact to the wire may be performed (S250).

On the other hand, when the third set length is set to the minimum value, as shown in FIG. 6, the foldable link 20 can be completely folded.

Thereafter, when the folding is completed, tension may be applied to the wire (S270). Specifically, by applying tension to the wire 30 through the actuator 40 after the folding of the foldable link 20 is completed, it is possible to prevent the wire 30 from being stretched.

Thereafter, the position of the wire may be fixed (S280). Specifically, the upper controller may transmit a mode change command to the lower controller, and the lower controller may switch the control mode of the actuator 40 to the position control mode. Accordingly, the actuator 40 fixes the position of the wire 30, and even when an external force acts on the foldable link 20, it is possible to keep the foldable link 20 unchanged.

Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiments presented herein, and those skilled in the art who understand the spirit of the present invention may add elements within the scope of the same spirit. However, other embodiments can be easily proposed by means of changes, deletions, additions, etc., but these will also fall within the scope of the present invention.

1: folding structure
10: frame part 10a: upper frame
10b: lower frame 20: folding link
21: fold line 30: wire
40: actuator
X: length of folding link L1: predetermined length

Claims (10)

As a deployment control method for deploying a folding link,
fixing the position of the wire connected to the folding link;
determining whether a deployment command is received;
Applying air pressure to the inside of the collapsible link when receiving a deployment command;
increasing the length of the wire by releasing the tension of the wire;
determining whether deployment of the collapsible link is complete; and
When the unfolding is completed, applying tension to the wire,
Increasing the length of the wire,
A control method of a foldable link capable of controlling a speed at which the foldable link is deployed by driving an actuator in a control mode in a position control mode and controlling a speed at which the length of the wire is increased. According to claim 1,
The folding link,
A control method of a foldable link formed in an origami method, capable of being folded or unfolded, and having an internal space. delete According to claim 1,
The step of determining whether the deployment is complete,
Control method of the foldable link for determining that the unfolding is completed when the length of the wire is greater than or equal to a first set length, and determining that the unfolding is incomplete when the length of the wire is less than the first set length. As a folding control method for folding a folding link,
determining whether a folding command is received;
discharging air inside the folding link when a folding command is received;
applying tension to the wire connected to the foldable link to reduce the length of the wire;
determining whether the length of the foldable link is equal to or less than a predetermined length;
applying a tensile impact to the wire when the length of the foldable link is equal to or less than the predetermined length;
determining whether folding of the foldable link is complete;
When the folding is completed, applying tension to the wire; and
A control method of a folding link comprising the step of fixing the position of the wire. According to claim 5,
The folding link,
A control method of a foldable link formed in an origami method, capable of being folded or unfolded, and having an internal space. According to claim 5,
Applying tension to the wire to reduce the length of the wire connected to the foldable link,
A control method of a foldable link capable of adjusting the folding speed of the folding link by driving the control mode of the actuator in the current control mode and controlling the length reduction speed of the wire through the current control of the actuator. According to claim 5,
The step of determining whether the length of the foldable link is less than or equal to a predetermined length,
When the length of the wire is equal to or less than the second set length, it is determined that the length of the foldable link is equal to or less than the predetermined length, and when the length of the wire is greater than the second set length, the length of the foldable link is determined to be greater than the predetermined length. Link control method. According to claim 5,
The step of applying a tensile impact to the wire,
A method of controlling a foldable link in which a tension impact pulse is generated by repeating a process of applying a maximum tension to the wire for a predetermined time and then removing the tension for a predetermined time. According to claim 5,
The step of determining whether the folding is complete,
Control method of the foldable link for determining that the folding is completed when the length of the wire is less than the third set length, and determining that the folding is incomplete when the length of the wire is greater than the third set length.

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