KR101435514B1 - Human power amplification robot estimating user's intension by detecting joint torque and control method thereof - Google Patents

Abstract

The present invention discloses a method for controlling the operation of the muscle strength-enhancing robot by estimating the intention of the user. A control method according to the present invention comprises the steps of: (a) measuring a torque in a rotating joint; (b) obtaining data necessary for attitude control by estimating the direction and speed of the operation intended by the user using the torque measurement value; (c) operating the rotary joint using the data.
According to the present invention, it is possible to feed back the torque of the rotating joint in real time, and to control the muscle strengthening robot to move immediately in accordance with the user's operation. Therefore, even if the user is wearing the muscle strength enhancing robot, the limitation of the operation is minimized and the operation becomes more natural.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a muscle strength enhancing robot for estimating an operation intention of a user by measuring a torque in a rotary joint,

The present invention relates to a muscle strength-enhancing robot for assisting or enhancing a muscle strength of a person, and more particularly, to a muscle strength-enhancing robot for estimating an operation intention of a user by using a torque measured at a rotary joint of the muscle strength- .

Generally, in an industrial field, it is often necessary to maintain a state in which a heavy heavy object is lifted or held for a long time. Such work requires inconveniences such as heavy manpower, heavy equipment, crane, and pulleys depending on the situation.

However, when people work directly, there is a high risk of industrial accidents as well as low work efficiency due to high work intensity. In case of using auxiliary equipment, relatively wide moving space or installation space is required, There is a problem.

In recent years, there has been a need for a muscle strengthening robot capable of supporting an additional force by using an actuator such as a motor or a hydraulic / pneumatic cylinder.

A muscle-strengthening robot is a robot that is used by a person to ride or ride on a joint mechanism operated by an actuator, which allows a robot to generate a force that is much larger than a user can with the help of an actuator. If the additional force is small, it is called a muscle-assisted robot.

However, in order to actually implement such a muscle-strengthening robot, it is necessary to minimize the size of the mechanism and to have a high output and rigidity while lightening it, and it is not easy to satisfy such conflicting requirements at the same time. It is a particularly difficult problem to control the user to perform the intended operation naturally without hindering the user's operation as much as possible.

The muscle strengthening robot should be able to perform the intended operation of the user in the state of being in proximity to or contact with the user's body. This is because the purpose of the muscle strengthening robot is to support a small number of people to exert the same force as many people, so that they can easily move even in a narrow space.

The basic structure of the muscle strength-enhancing robot is a form that wraps the body of the user or can move in parallel with the joints of the person. In such a case, if the robot exists at the proximity of the user, the motion of the user may be interrupted.

Therefore, the muscle strengthening robot should be able to recognize and estimate the user's motion without interfering with the user's motion. The user must perform the desired operation, and the strength-enhancing robot must be able to operate to support the user's operation by estimating the user's motion at the user's proximity. Since the muscle strengthening robots are located at a distance close to the user, a method of recognizing the user's motion at a long distance is not preferable.

Conventional methods for recognizing the user's motion at a close distance include a method for measuring and controlling the user's brain waves, a method for estimating the motion of the muscles by measuring the EMG signal, a method for estimating the movement of the muscles by measuring the change in the hardness of the muscle And the like.

However, in order to use such a method, there is a problem in that it is difficult to precisely control the muscle strength increasing robot because the measurement error is large according to the contact state of the sensor or the body characteristics of the user.

SUMMARY OF THE INVENTION The present invention provides a method for estimating an operation intention of a user using torque measured at each rotary joint of a muscle strength-enhancing robot and controlling the motion of each rotary joint more precisely using the torque It has its purpose.

In order to achieve the above-mentioned object, the present invention provides a method of controlling an operation of a muscle strength-enhancing robot having a rotary joint, the method comprising the steps of: (a) measuring a torque in the rotary joint; (b) obtaining data necessary for attitude control by estimating the direction and speed of the operation intended by the user using the torque measurement value; (c) operating the rotational joint using the data.

In the step (b) of the control method according to the present invention, the necessary torque of the rotary joint according to the posture of the muscle strength increasing robot is calculated, and data necessary for posture control is acquired using the torque measurement value and the necessary torque .

The present invention also provides a muscle strength-enhancing robot to be worn by a user, comprising: a skeleton having a plurality of rotational joints as a part for performing a muscle strength increasing function; A restraint mechanism for restraining the user's body; a joint part corresponding to at least one of the plurality of rotary joints; and a torque sensor installed at the joint part and having a torque sensor whose one end is connected to the skeleton; And a robot controller for estimating an operation intention of the user by using the torque measured by the torque sensor and controlling the plurality of rotational joints according to a result of the estimation.

The muscle strength-enhancing robot of the present invention is characterized in that one side of the torque sensor is provided so as to rotate freely coaxially with one of the rotary joints of the plurality of rotary joints of the framework.

Further, the muscle strength-enhancing robot of the present invention may be characterized in that an elastic member is provided on the joint part of the user-torque measuring device to provide a load that can be controlled by a user.

The present invention also includes a skeleton having a plurality of rotational joints, a joint portion corresponding to at least one of the plurality of rotational joints, and a torque sensor installed at the joint portion and having a torque sensor having one side connected to the skeleton (A) when a user wearing the user torque measuring apparatus moves, a direction and a velocity of an operation intended by the user are measured using the torque measured by the torque sensor, And acquiring data necessary for attitude control; (b) operating the rotational joint using the data.

According to the present invention, it is possible to feed back the torque of the rotary joint in real time, and to control the muscle strengthening robot to move immediately in accordance with the user's operation. Therefore, even if the user is wearing the muscle strength enhancing robot, the limitation of the operation is minimized and the operation becomes more natural.

Also, since the muscle strength-enhancing robot supports the force in the direction and the size desired by the user, the load actually felt by the user can be immediately reduced.

1 is a view showing a rotating joint having a body restraint mechanism at both ends according to an embodiment of the present invention;
2 is a view showing a multi-shaft joint having a body restraint mechanism at both ends according to an embodiment of the present invention
3 is a view illustrating a case where a muscle-strength-enhancing robot according to an embodiment of the present invention is worn on an arm;
4 is a view showing a case where a muscle strength-enhancing robot according to an embodiment of the present invention is worn on a leg;
5 is a view illustrating a waist portion skeleton of a muscle strength increasing robot according to an embodiment of the present invention;
6 is a view showing a case where a muscle-strength-enhancing robot according to another embodiment of the present invention is worn on an arm
7 is a view showing only the user torque sensing device
8 is a view showing a case where a muscle strength-enhancing robot according to another embodiment of the present invention is worn on a leg

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

One embodiment of the present invention is characterized in that torque is measured at a rotation joint of a muscle-strength-enhancing robot corresponding to a human body joint of a user, and the movement of the rotary joint is immediately controlled using the measured torque.

The torque can be measured by directly installing a torque sensor on the rotary joint or by converting the measured value of the current supplied to an actuator such as a motor for driving the rotary joint. Since the method of estimating the torque using the current is well known in the field of the actuator, description thereof will be omitted.

FIG. 1 shows a basic rotational joint structure of a muscle-strength-enhancing robot according to an embodiment of the present invention, wherein an arbitrary n-th link 11 and an n + 1-th link 12 are connected to each other at an n-th rotary joint 20 And is rotatably connected.

At this time, each of the links 11 and 12 must be able to be restrained to a corresponding body part of the user, and each of the links 11 and 12 is provided with a restricting mechanism 30 for restricting the user's body. This is because the torque of the rotary joint 20 can be changed by the movement of the user.

2 is a diagram illustrating a multi-shaft rotary joint 20 '(hereinafter, referred to as' multi-shaft joint') in which a plurality of rotary shafts intersect at one point, such as a shoulder, a pelvis, or the like. In this case, the reference link and the distal end portion of the multiaxial joint 20 'must be constrained to the corresponding body part of the user through the restraint mechanism.

3 illustrates an upper limb skeleton 50 of a muscle-strength-enhancing robot including a multiaxial joint 20 'and a rotary joint 20. The upper and lower ends of a multiaxial joint 20' corresponding to a human shoulder joint Are restrained by the restricting mechanism (30) to the shoulder and upper arm of the user, respectively. Also, each link connected to the rotary joint 20 corresponding to the elbow joint of the person is restrained to the upper arm and the forearm (cuff) by the restricting mechanism 30, respectively.

4 is a diagram illustrating a lower skeleton 50 'of a muscle-strength-enhancing robot including a multiaxial joint 20' and a rotary joint 20, and is a cross-sectional view of an upper end portion of a multiaxial joint 20 ' And the lower ends thereof are restrained by the restraint mechanism 30 to the waist and thighs of the user, respectively. Each of the links connected to the rotary joint 20 corresponding to the knee joint of the human being is restrained by the restricting mechanism 30 to the thigh and the lower leg respectively and each link connected to the rotary joint 20 corresponding to the ankle is restrained by the restraint mechanism 30) to rest on the lower leg and lower ankle, respectively.

However, this joint is not limited to the upper skeleton 50 or the lower skeleton 50 ', and may include one or more rotary joints 20 corresponding to the waist joint of the user as shown in Fig.

The method of controlling the posture by estimating the intention of the user in the muscle strengthening robot is as follows.

Basically, the robot control unit of the muscle-strength-enhancing robot calculates the torque required to maintain the posture every set period and controls the actuator such as a motor to output such torque.

In this state, when the wearer of the muscle-strength-enhancing robot moves to unfold or bend the joint, the torque measured at each joint of the muscle-strength-enhancing robot becomes smaller or larger due to the force generated in the wearer's joint. Or can be measured in real time by converting the amount of current of the actuator driving each joint.

On the other hand, a multi-axial joint is constituted so that one end thereof is confined to the body, and is restrained to the body at the other end beyond the two-axis or three-axis rotation joint. In a multi-axial joint, the rotational axes of several joints meet at a single point, so the measured torque can be expressed as the rotational force of three rotational axes: actual roll, yaw, and pitch. Therefore, the torque measured in the multi-axis joint can be calculated as the sum of the required torques of the three rotational shafts, and the rotational shafts can be controlled using the sum. For this control, a means for measuring the posture of each joint constituting the multi-axis joint is required.

The robot control unit can detect the torque change amount and calculate the direction and speed of the force intended by the user.

For example, when an object is lifted by the upper limb skeleton 50 of the muscle force amplifying device, a constant torque is applied to the joint corresponding to the elbow. If the user moves in a direction in which the arm restrained by the upper limb skeleton 50 is lowered, The force that the user's arm is pushed down will increase the torque measured at that joint. The robot control unit rotates the joint so that the calculated torque is maintained so as to support the load of the object in the attitude, thereby controlling the operation so that the load added by the user's arm is removed.

It is also possible to control the operation to be faster as the difference between the calculated torque and the actually measured torque is larger. However, the rate of increase in speed may vary depending on the purpose of use and the average additional load. Therefore, the robot controller can estimate the direction and speed of the operation intended by the user through the amount of torque change.

When the direction and speed of the motion intended by the user are estimated in this manner, data necessary for attitude control of the muscle-strength-enhancing robot can be obtained by using a general robot kinetic equation. By using the actuator and the posture of the muscle- Can be adjusted as intended. It is needless to say that the kinematic strengthening robot has to store the kinematic characteristics of each joint, the angle of the joint, the kinetic velocity of the joint, and the related kinetic program in advance.

However, this method can cause an operation error when an external force or an external impact is applied to change the torque rapidly. Therefore, when the posture control of the muscle strength-enhancing robot is performed by the above-described method, It is preferable to control so as to be always present in the time domain.

This method can be applied even when a new load is added to the muscle strengthening robot.

When the muscle strengthening robot performs actions such as grasping or lifting a heavy object, the torque applied to each joint varies depending on the size of the load, the working position, the posture, and the like.

When an object is lifted by the upper limb skeleton of the muscle strength increasing robot, the torque at each joint changes as the center of gravity changes. When such a change in torque occurs within a controllable range, the robot controller can automatically estimate the mass and center of gravity of the object. That is, the torque calculated at each joint in the posture of lifting the object can be expressed by the following equation (1).

Also, the torque increased by the newly increased load in the joint n can be expressed by the following equation (2).

By calculating the equations measured on each axis, the load and center of gravity of the object can be calculated.

By adding the load obtained here to the existing data, it becomes possible to operate the muscle strengthening robot in a state where a new load is added. That is, when the torque required for each joint in the no-load state and the torque due to the additional load are added to obtain a new reference torque and a difference between the torque and the torque measured at each joint is calculated, Since the direction can be determined, it is possible to control so that an object can be lifted or moved.

On the other hand, in the above-described embodiment, the intention of the user is estimated by directly measuring the torque of the rotating joint constituting the skeleton of the strength-enhancing robot.

However, when a sudden impact is applied to a skeleton portion of a muscle-strength-enhancing robot or a collision occurs, there is a problem that it is difficult to judge whether a sudden torque change is intended by a user.

In order to solve such a problem, it is preferable to use a user torque measuring device 90 capable of measuring torque at each joint of the user's body as illustrated in Fig.

The user's torque measuring device 90 is configured to have the same or corresponding freedom and range of motion as the upper backbone 50 of the muscle-strength-enhancing robot, in the form of a joint mechanism worn by the user. And may have the same or corresponding freedom and motion range as the skeleton of the lower limb or the lower limb.

Preferably, as shown in Fig. 7, a plurality of links 91 each having a joint portion 94 for each position corresponding to each joint of the muscle strength-enhancing robot, and a plurality of links 91 each capable of coupling each link 91 to the user's body And a restricting mechanism 92. Further, a torque sensor 100 is installed on the rotary shaft of each joint portion 94.

At this time, in order to facilitate torque measurement, an elastic member such as a spring may be provided on each joint portion 94 to provide a load (restoring force) to the extent that the user can control. When the elastic member is installed on the joint part 94, even if the joint part 94 rotates by the same angle, the magnitude of the restoring force changes the magnitude of the torque, so that it is possible to faithfully reflect the operation intention of the user.

The torque sensor 100 is for measuring a torque change occurring in the joint portion 94 of the user torque measuring device 90 by a user's motion.

6 shows that one side of the torque sensor 100 is connected to the upper side skeleton 50 of the muscle strength increasing robot 50. This is for the purpose of fixing the position of the torque sensor and the upper side skeleton 50 of the muscle strength increasing robot, , 20 ').

It is preferable to connect the torque sensor 100 to the joints 20 and 20 'of the strength-enhancing robot in order to precisely control the operation. To prevent the torque value from being changed by the joints 20 and 20' You can install it.

As described above, it is most preferable that the user torque measuring device 90 completely separate mechanically from the upper backbone 50 of the muscle strength increasing robot, which generates the actual mechanical output, except for the torque sensor 100. [

However, if a minimum displacement capable of measuring the torque change of the user's joint can be secured, a flexible material or a mechanical structure may be added without completely separating the user's torque measuring device 90 from the upper skeleton 50 of the muscle- It is also possible to interconnect them. The connecting member attached to the upper limb skeleton 50 or the upper limb skeleton 50 of the muscle-strength-enhancing robot may be configured to surround the user's torque measuring device 90.

The torque sensor 100 connected to each of the joints 94 is moved in the direction of the user's torque measurement device 90 as the user moves in a desired direction while restricting his or her body to the restraint mechanism 92 of the user- And the upper skeleton 50 of the muscle-strength-enhancing robot 50 can be measured. Further, the robot control unit estimates the user's operation intention by using it, and calculates data necessary for attitude control.

It is of course possible to control the operation of the lower skeleton 50 'of the strength-enhancing robot by wearing the user's torque measuring device 90 on the user's lower limb as shown in FIG.

Although not shown in the drawings, the user torque measuring device 90 may include a joint portion corresponding to the waist skeleton of the muscle strength increasing robot, and a torque sensor may be provided at the joint portion, and the torque sensor may be attached to the corresponding waist skeleton or waist joint When connected, the robot's posture can be controlled by estimating the user's waist motion.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Of course it belongs.

20: rotating joint 20 ': multi-axial joint
30: restraint mechanism 50: upper limb skeleton
50 ': lower skeleton 90: user torque measuring device
91: Link 92: Retention mechanism
94: joint part 100: torque sensor

Claims (7)

delete delete 1. A muscle strength-enhancing robot for use by a user, comprising:
A skeleton having a plurality of rotational joints, the skeleton having a plurality of rotational joints;
A plurality of links spaced apart from the skeleton and connected to each other by a joint corresponding to a bodily joint of a user, a restraint mechanism provided on at least one of the plurality of links to restrain a user's body, A user torque measuring device installed at the joint part for measuring a torque and having a torque sensor whose one side is connected to the skeleton;
A robot controller for estimating an operation intention of the user by using the torque measured by the torque sensor and controlling the plurality of rotational joints according to a result of the estimation;
A muscle strengthening robot including The method of claim 3,
Wherein the one side of the torque sensor is coupled to the rotating joint so as to freely rotate coaxially with one of the plurality of rotating joints of the skeleton. The method of claim 3,
Characterized in that an elastic member is provided on the joint portion of the user torque measuring device to provide a load that can be controlled by a user, A skeleton having a plurality of rotational joints, a plurality of links spaced apart from the skeleton and connected to each other by joints corresponding to the bodily joints of the user, at least one link of the plurality of links, And a user torque measuring device provided on the joint part for measuring a torque of the joint part and having a side connected to the skeleton, the method comprising the steps of: As a result,
(a) measuring a torque at the joint of the user torque measuring device every set period;
(b) when the torque measured at the joint part of the user torque measuring device changes due to the movement of the user wearing the user torque measuring device, the direction and speed of the operation intended by the user are estimated using the torque change information, Obtaining data necessary for control;
(c) operating the rotary joint provided in the framework using the data
A control method of a muscle-strength-enhancing robot including The method according to claim 6,
Wherein in the step (c), the rotation joint is operated at a higher speed as the torque change amount measured in the step (b) is larger.

Images