KR101628703B1

KR101628703B1 - A finger motion measurement system and measurement method of finger motion

Info

Publication number: KR101628703B1
Application number: KR1020150021069A
Authority: KR
Inventors: 배준범; 이정수; 유범재
Original assignee: 울산과학기술원; 재단법인 실감교류인체감응솔루션연구단
Priority date: 2015-02-11
Filing date: 2015-02-11
Publication date: 2016-06-21

Abstract

The finger movement measuring system according to the present invention comprises: a ring-shaped structure worn on a finger of a user; A carbon wire whose one end is attached to the ring-like structure; A sensing module having a potentiometer for attaching the other end of the carbon wire to measure the moving distance of the carbon wire; A hand-held housing to which the sensing module is attached; And a wireless communication module for externally transmitting the finger movement information measured through the movement distance and the rotation angle. The present invention can be used by various hand size users. There is a definite effect.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a finger movement measurement system and a measurement method,

The present invention relates to a finger movement measurement system and method, and more particularly, to a finger movement measurement system and method for measuring a finger movement, which enables a user to wear a ring- To a system and to a measurement method.

Because hands are one of the richest sources of tactile sensing, elaborate and complex manipulations can not be achieved without hands. For the development of a wearable system for hands, analysis of unconstrained hand motion must precede. Extensive research has been conducted to measure finger movements with a simple system.

First, similar approaches using optical linear encoders (OLE) have been attempted, but coarse and wide wire cables for the encoders and optical encoders attached to the fingers can interfere with the natural movement of the fingers.

In addition, three-dimensional magnetic position sensors were applied to finger joint angle measurement, and they were able to measure finger movements in three dimensions. However, the required peripherals may be an obstacle to the movement of the unconstrained hand.

A fiber optic sensor was also used for angle measurement. Fiber optic sensors are attached to gloves for easy wearing, but optical sensors must be carefully bent to measure joint angles. In addition, the mobility is extremely limited by the required peripheral devices such as laser diodes and optical power systems.

On the other hand, while flexible resistance is commercially available and has good performance in terms of resolution and repeatability, it is inefficient in cost and difficult to integrate with other systems such as the hand exoskeleton system.

Attempts have been made using optical encoders, magnetic position sensors, fiber optic sensors and flexible resistors, etc., but due to the limited space of the hand, a compact and simple measurement system and a system capable of measuring finger motion unrestrainedly Is not fully developed.

In order to solve the above-mentioned problems, as shown in Fig. 1, by wearing a glove made of a flexible wire having one end attached to a sensing module attached to a wrist portion and the other end attached to a finger joint portion, A relatively light and compact finger motion measurement system was applied so as not to interfere with the natural movement of the hand but the movement of the glove due to the elongation of the hand There is a problem that can not be accurately measured.

In addition, the gloved finger motion measuring device has a problem that it is troublesome for a user of various hand sizes to use.

Korean Patent Application No. 10-2014-0056528

In order to solve the above-described problems, the present invention provides a finger movement measuring system which enables a user to use a ring-type structure directly on a finger joint so as to be able to use various hand sizes, And to provide a measurement method.

According to an aspect of the present invention, there is provided a finger movement measuring system comprising: a ring-shaped structure worn on a user's finger; A carbon wire whose one end is attached to the ring-like structure; A sensing module including a potentiometer for measuring the moving distance of the carbon wire while maintaining the tension by attaching the other end of the carbon wire; A hand-held housing to which the sensing module is attached; And an angle sensor for calculating a rotation angle of the corresponding joint in the finger based on the movement distance; A wireless communication module for transmitting finger movement information measured through the movement distance and the rotation angle to the outside; And a control unit.

Preferably, in order to achieve the above-mentioned object, the ring structure of the finger motion measurement system according to the present invention comprises: a first ring-like structure sandwiched between a first joint and a second joint of a finger; And a second ring-like structure sandwiched between the first joint and the second joint of the finger, wherein the carbon wires have different lengths, one end of which is connected to the first ring-like structure and the other of which is connected to the second ring- And the sensing module 130 is connected to the other end of the first and second carbon wires, one end of which is coupled to the first ring-like structure and the other end of which is connected to the second ring- And a first and a second potentiometer connected to each other.

The finger movement measuring system and the measuring method according to the present invention can be used by users of various hand sizes by wearing the ring-shaped structure on the finger joints, and it is possible to clearly recognize the positional relationship that varies depending on the finger movements .

1 is a photograph of a conventional wearable sensing glove,
FIG. 2 is a diagram of a finger structure for explaining a finger structure,
Figure 3 is a system for measuring finger movement according to the present invention,
4 is an operation diagram of a finger moving measurement system according to the present invention,
5 and 6 are side sectional views of a finger for explaining a finger motion measurement system according to the present invention, and Fig.
7 is a schematic diagram of a finger motion measurement system according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concepts of the terms appropriately The present invention should be construed in accordance with the meaning and concept consistent with the technical idea of the present invention.

Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.

Prior to the detailed description of the present invention, the skeletal structure of the hand will be described in detail.

The hand consists of a complex combination of ligaments of the bones, muscles and joints, and the direction and extent of the hand movements are determined by these. In order to accurately measure the finger movements, an understanding of the anatomical structure of the hand is required.

Hand movements are achieved by 19 bones, 19 joints and 29 muscles. Each finger, except the thumb, has three bones, a distal, middle and proximal phalanx, and three proximal interphalangeal joints (PIP ) joint, a metacarpophalangeal joint (MCP) joint, and a distal interphalangeal joint (DIP) joint. The thumb has only two bones: the endodermic bone, the first bony bone, and the two joints, the interphalangeal (IP) joint, and the MCP joint. The metacarpal phalanx bones meet the wrist at the carpometacarpal (CMC) joints. IP joints, including the PIP and DIP joints, have 1-degrees of freedom for flexion / extension movements and MCP joints have 2-degrees of freedom for flexion / extension and abduction / adduction movements .

In order to manipulate objects by hand, flexion / extension movements are usually required more than movements of abduction / abduction. Accordingly, there is a great demand for a flexion / extension motion measurement system for a finger that does not disturb natural finger movements.

3, the finger movement measuring system according to the present invention includes a ring structure 110, a carbon wire 120, a sensing module 130, a back housing 140, a wire guide part 150, A sensor 160, and a wireless communication module 170.

4, which is an operation drawing of the finger movement measuring system according to the present invention, the finger movement measuring system according to the present invention can be worn by putting on a finger of a person in a ring form, The ring-like structure 110 is composed of a first ring-like structure 111 fitted to the second node and a second ring-shaped structure 112 fitted to the third node.

The carbon wire 120, which is stiff in the longitudinal direction but does not bend and break well and has its own elasticity, has first and second carbon wires, one end of which is connected to the first and second ring-like structures 111 and 112, (121, 122).

Particularly, since the carbon wire 120 has a self-elasticity, it can replace the spring incorporated in the potentiometer in the prior art. Using the very thin carbon rod, the finger movement can be measured .

Here, the carbon wire 120 is not limited to a carbon material. As mentioned above, the carbon wire 120 may be made of a flexible thin plastic wire or other composite material, which does not bend or break well and has self-elasticity.

The sensing module 130 includes first and second potentiometers 131 and 132 connected to the other ends of the first and second carbon wires 121 and 122, respectively.

The hand-held housing 140 has a fingerless glove shape and supports the wire guide unit 150 and the sensing module 130 to be mounted.

The wire guide part 150 is provided with a wire guide part 150 between the ring-type structure 110 and the sensing module 130 for linear alignment of the carbon wire 120, .

The angle sensor 160 may be mounted on one side of the hand-held housing 140 to sense a bending angle for measuring the wrist motion, and can be easily removed from the hand-held housing 140.

The wireless communication module 170 receives measured wrist motion data from the sensing module 130 and the angle sensor 160 via a Bluetooth-like local communication and transmits the wrist motion data to an external device.

The wireless communication module 170 may be a wearable device such as a smart clock.

The finger motion measurement by the finger motion measurement system according to the present invention having the above-described configuration will be described.

That is, in the present invention, a finger motion measurement system using linear potentiometers 131 and 132 and the carbon wire 120 is proposed. The carbon wire 120 is attached to the back surface of the finger. As the carbon wire 120 moves by finger movement, the joint angle can be calculated by measuring the change in length of the carbon wire 120. [

Since only the movement of the proximal interphalangeal (PIP) is dependent on the distal interphalangeal (DIP) joint, only two of the first and second potentiometers 131 and 132 are applied to each finger.

The compact sensing module 130, consisting of ten linear potentiometers, is attached to the fingerless housing 140 with no fingers.

More specifically, the cross section of the finger for bending / stretching movement is as shown in Fig.

The lengths C ₁ , C ₂ and C ₃ of each finger element can be measured in advance and the positions of the finger tips can be expressed as follows when joint angles θ ₁ , θ ₂ and θ ₃ are measured.

As shown in Equations (1) and (2), only three joint angles are required to describe the flexion / extension motion of each finger, but it is not easy to measure the joint angle of the finger due to the limited space of the finger. In addition, the angle measurement system must be sufficiently light and compact to not interfere with the natural movement of the hand.

In the present invention, the carbon wire 120 and the sensing module 130 are applied to measure flexion / extension movements of the finger. This basic concept of the present invention is shown in Fig. For the sake of clarity, an illustration of only one joint is shown in the figure.

The carbon wire 120 may be attached to a predetermined position of the finger through a method of binding one end of the carbon wire 120 to the upper end of the ring-shaped structure 110 as shown in FIG. 6A (point A in the finger) have.

Since the finger joint movement can be considered as a rotational movement about a fixed joint (point B in the finger), the kinematics of one joint can be expressed as shown in FIG. 6B. As the fingers are bent, the connected lines are moved because the wrinkles of the finger joints are stretched. The moved distance DELTA L is calculated as follows.

Here, r ₁ is the diameter of the finger joint, and θ ₁ is the joint angle. The diameter of the finger joint can be measured directly. The length change ? L ₁ is measured by a linear potentiometer installed as ? P , as shown in Fig. 6C. Therefore, the joint angle is calculated as follows.

When the finger is spread to its original position, the carbon wire 120 returns to its original position by its own elasticity. In the absence of self-elasticity, the flexible wire is loosened as in Figure 6d, which allows the system to measure only one finger flexion. In the present invention, the carbon wire 120 transmits the movement of the finger to the potentiometer and maintains the original shape by self-elasticity.

On the other hand, before examining the multiple joint cases, the mutual dependency between the finger joints must be discussed first. DIP joint movements are known to be unable to move independently, and DIP joint movements are dependent on PIP joints. The relationship between them can be approximated as follows.

Here, θ _DIP and θ _PIP represent the angles of the DIP and PIP joints, respectively. However, a more accurate relationship is required to measure both joint angles by only one measurement of the PIP joint. By obtaining the exact relationship between the DIP joint and the PIP joint, only two measurements for a single finger of the 3-DOF are needed. The exact relationship between the DIP joint and the PIP joint is obtained experimentally as described below.

Considering the dependency between the DIP joint and the PIP joint, the present invention is designed as shown in FIG. Similar to the case of one joint, each joint angle is measured by the first and second potentiometers 131, 132 constituting the sensing module 130.

When a finger from Figure 7a assumed bent in Figure 7b, the moving distance of ΔL ₁ and ΔL ₂ of the enclosed point is measured as follows by two linear potentiometer is installed.

The joint angles are calculated as follows.

Therefore, the joint angles are obtained by the potentiometers as follows.

In the present invention, only the required measurements are the changed distances of the bound points, which are measured by the carbon wire 120 and the first and second potentiometers 131, 132. One of the advantages of the present invention is that the carbon wire 120 can bend and thus the wire need not be linearly aligned with the finger, but as mentioned above, A wire guide part 150 may be formed between the ring-type structure 110 and the sensing module 130 for linear alignment of the ring-shaped structure 110 and the sensing module 130.

Although the present invention has been described in connection with certain exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. Therefore, the scope of the present invention should not be limited by the described embodiments, but should be defined by the appended claims and equivalents thereof.

110: Ring-shaped structure
120: carbon wire
130: sensing module
140: Housing on the back of the hand
150:
160: Angle sensor
170: Wireless communication module

Claims

A system (100) for measuring movement of a finger,
A ring-shaped structure 110 to be worn on a user's finger;
A carbon wire 120 having one end attached to the ring-like structure 110;
A sensing module 130 comprising a potentiometer for measuring the moving distance of the carbon wire 120 with the other end of the carbon wire 120 attached thereto;
A hand-held housing 140 to which the sensing module 130 is attached; And
A wireless communication module 170 for transmitting finger movement information measured through the movement distance to the outside; Lt; / RTI >
And an angle sensor (160) for measuring a movement of the wrist when the finger is moved.

The method according to claim 1,
The ring-like structure 110 is
A first ring-shaped structure (111) fitted to a second node between the first joint and the second joint of the finger; And a second ring-like structure (112) that fits into a first node between the second joint and the third joint of the finger.

3. The method of claim 2,
The carbon wire 120
And first and second carbon wires (121, 122) of different lengths, one end of which is coupled to the first ring-like structure (111) and the second ring-like structure (112), respectively, Measuring system.

The method of claim 3,
The sensing module (130)
The first ring-shaped structure 111 and the second ring-shaped structure 112 are connected to the other ends of the first and second carbon wires 121 and 122 respectively connected to the first ring-shaped structure 111 and the second ring- 2 potentiometers (131, 132).

5. The method of claim 4,
Wherein the angle of the first and second joints is calculated from the changed distance of the attached point measured by the first and second carbon wires and the linear potentiometer of the sensing module as the finger moves. Motion measurement system.

The method of claim 3,
Wherein the first and second carbon wires (121, 122) and the sensing module are installed for each finger.

The method according to claim 1,
Wherein the carbon wire (120) has self-elasticity.

3. The method of claim 2,
Wherein the first, second, and third joints are a DIP joint, a PIP joint, and a MCP joint, respectively.

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A method of measuring a finger movement of a user wearing a ring-shaped structure,
(a) a ring-like structure 110 connected to one end of a carbon wire 120, the other end of which is connected to the sensing module 130, to the middle and proximal phalanxes of each finger, step;
(b) measuring a moving distance of the carbon wire (120) by the sensing module (130) according to the finger movement; And
(c) calculating a rotation angle of the corresponding joint in the finger based on the movement distance,
And transmitting finger movement information measured through the movement distance and the rotation angle to the outside.

11. The method of claim 10,
The ring-like structure 110 is
A first ring-shaped structure (111) fitted to a second node between the first joint and the second joint of the finger; And a second ring-like structure (112) fitted to a first node between the second joint and the third joint of the finger.

12. The method of claim 11,
The carbon wire 120
And first and second carbon wires (121, 122) of different lengths, one end of which is coupled to the first ring-like structure (111) and the second ring-like structure (112), respectively, How to measure.

13. The method of claim 12,
The sensing module (130)
The first ring-shaped structure 111 and the second ring-shaped structure 112 are connected to the other ends of the first and second carbon wires 121 and 122 respectively connected to the first ring-shaped structure 111 and the second ring- 2 potentiometers (131, 132).

14. The method of claim 13,
Wherein the angles of the first and second joints are calculated from the changed distance of the attached point measured by the linear potentiometer of the first and second wires and the sensing module according to the movement of the finger. Way.

13. The method of claim 12,
Wherein the first and second carbon wires (121, 122) and the sensing module are installed for each finger.

13. The method of claim 12,
Wherein the carbon wire (120) has self-elasticity.

12. The method of claim 11,
Wherein the first, second, and third joints are a DIP joint, a PIP joint, and a MCP joint, respectively.

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