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| United States Patent Application |
20080078030
|
| Kind Code
|
A1
|
|
LEE; Ju Jang
;   et al.
|
April 3, 2008
|
INTELLIGENT BED ROBOT EQUIPPED WITH PRESSURE SENSOR-PROVIDED MATTRESS AND
GRIPPER-PROVIDED SUPPORTING ROBOT ARM
Abstract
Disclosed herein is an intelligent bed robot. The intelligent bed robot
includes a pressure sensor-provided mattress, an intelligent robot arm,
transfer rails, and at least one gripper. The pressure sensor-provided
mattress monitors the position, posture and motion of a user on a bed in
real time, and assists the user. The intelligent robot arm includes
vertical bars disposed on two opposite sides of the bed and configured to
have a predetermined length, a horizontal bar configured to connect the
vertical bars to each other, and torque sensors disposed at lower ends of
the vertical bar, and measures horizontal and vertical forces applied by
the user. The transfer rails guide the intelligent robot arm along a path
of movement. The gripper is coupled to the horizontal bar of the
intelligent robot arm, and is provided with a finger unit capable of
picking up an object.
| Inventors: |
LEE; Ju Jang; (Daejon, KR)
; SEO; Kap Ho; (Daejon, KR)
; OH; Chang Mok; (Daegu, KR)
|
| Correspondence Address:
|
ADAM K. SACHAROFF;MUCH SHELIST FREED DENENBERG AMENT&RUBENSTEIN,PC
191 N. WACKER DRIVE, SUITE 1800
CHICAGO
IL
60606-1615
US
|
| Assignee: |
KOREA ADVANCED INSTITUTE OF SCIENCE AND TECHNOLOGY
Daejeon
KR
|
| Serial No.:
|
833285 |
| Series Code:
|
11
|
| Filed:
|
August 3, 2007 |
| Current U.S. Class: |
5/616; 5/618; 5/623 |
| Class at Publication: |
5/616; 5/618; 5/623 |
| International Class: |
A47C 17/86 20060101 A47C017/86 |
Foreign Application Data
| Date | Code | Application Number |
| Sep 28, 2006 | KR | 10-2006-0094678 |
Claims
1. An intelligent bed robot, comprising:a pressure sensor-provided
mattress configured to monitor a position, posture and motion of a user
on a bed in real time, and assisting the user;an intelligent robot arm
configured to comprise vertical bars disposed on two opposite sides of
the bed and configured to have a predetermined length, a horizontal bar
configured to connect the vertical bars to each other, and torque sensors
disposed at lower ends of the vertical bar, and to measure horizontal and
vertical forces applied by the user;transfer rails configured to guide
the intelligent robot arm along a path of movement; andat least one
gripper coupled to the horizontal bar of the intelligent robot arm so
that it can move horizontally along the horizontal bar and rotate around
the horizontal bar, and provided with a finger unit capable of picking up
an object.
2. The intelligent bed robot as set forth in claim 1, further comprising a
control box for reading pressure values of the pressure sensors by
sequentially scanning the pressure sensors using a multiplexer, and
delivering data about the pressure values to a main computer in a
pressure measurement distribution image form.
3. The intelligent bed robot as set forth in claim 1, wherein the robot
arm has two operation modes, including a follow mode, in which the user
can control the robot arm using his or her command so as to obtain
support means using the robot, and a support mode, in which the user's
body is secured and supported using the acquired support means.
4. The intelligent bed robot as set forth in claim 3, wherein the follow
mode conducts work using a fuzzy network.
5. The intelligent bed robot as set forth in claim 1, wherein the
horizontal bar has a central separation element so that a length of the
horizontal bar can vary with relative locations of the vertical bars.
6. The intelligent bed robot as set forth in claim 1, wherein the pressure
sensor-provided mattress monitors a person on a bed using a Principal
Component Analysis (PCA) algorithm, the PCA algorithm performing:a first
step of determining a human's recognition target pattern and relating
pressure sensor dataset for pattern classification;a second step of
extracting feature points by calculating covariance of the pressure
sensor data;a third step of determining a number of feature points
capable of maximizing information classification between respective
pieces of pattern data; anda fourth step of performing pattern
recognition by comparing new incoming pressure sensor data with
predetermined feature points.
7. The intelligent bed robot as set forth in any one of claims 1 to 6,
wherein the robot arm works in a command mode of conducting operations in
response to the user's command, which includes user's voice, and in an
automatic mode of conducting work according to a predetermined work
command.
8. The intelligent bed robot as set forth in claim 1, wherein:the
horizontal bar has a ball screw disposed therein along a length of the
horizontal bar; andthe gripper includes:a first gear structure provided
with threads so that the first gear structure can guide the gripper
through linear movement in conjunction with the ball screw;a second gear
structure formed of a worm gear that works in conjunction with the first
gear structure so that the gripper can rotate around the horizontal bar;
anda third gear structure configured such that the finger unit can
conduct work of picking up an object.
9. The intelligent bed robot as set forth in claim 8, wherein the ball
screw and the first gear structure work in conjunction with each other
along a longitudinal hole that is formed along the length of the
horizontal bar.
10. The intelligent bed robot as set forth in claim 1, wherein the finger
unit has a shape of a human hand, includes a stationary first finger and
a movable second finger, and performs work of gripping an object through
overlapping of the first and second fingers.
11. The intelligent bed robot as set forth in claim 10, wherein the first
finger is provided with an accommodation part so that the first finger
can accommodate the second finger when the first finger and the second
finger overlap each other.
12. The intelligent bed robot as set forth in claim 10, wherein the first
finger and the second finger have respective rubber portions that come
into contact with an object.
13. The intelligent bed robot as set forth in claim 1, wherein the
intelligent bed robot is controlled using a Controller Area Network (CAN)
device.
Description
BACKGROUND OF THE INVENTION
[0001]1. Field of the Invention
[0002]The present invention relates generally to a bed robot that is
equipped with a pressure sensor-provided mattress and a supporting robot
arm, and, more particularly, to an intelligent bed robot that is equipped
with one or more grippers to perform the work of picking up objects.
[0003]2. Description of the Related Art
[0004]With the extension of the average life expectancy of people today
and the development of medical technology, the elderly population is
steadily increasing throughout the world. Accordingly, there is an urgent
need for a system for assisting the elderly population in their
activities.
[0005]Electric beds, targeting the elderly, the weak and the disabled,
have a function that enables the heights and angles of the upper part and
legs thereof to be freely adjusted. However, such electric beds provide
only the most basic functions.
[0006]The present applicant proposed `Intelligent Bed Robot equipped with
Pressure Sensor-provided Mattress and Supporting Robot Arm,` for which a
patent application was submitted on Oct. 15, 2004 and Korean Patent No.
10-0605750 was granted. With this, the applicant attempted to provide a
bed robot that can provide more familiar and convenient services to
users.
[0007]FIG. 1 shows a patented intelligent bed robot equipped with a
pressure sensor-provided mattress and a supporting robot arm.
[0008]Referring to FIG. 1, the robot 100 includes a pressure
sensor-provided mattress 104, a supporting robot arm 102, a shelf, and
transfer rails 108. The pressure sensor-provided mattress 104 assists a
person on a bed while monitoring the location, posture and motion of the
person on the bed in real time. The supporting robot arm 102 includes two
right and left motors and two torque sensors, and functions to support
the person on the bed based on the information obtained by monitoring the
mattress. The shelf is attached to the supporting robot arm for use. When
not in use, the shelf is moved to and hidden in the space under the
intelligent bed robot. The transfer rails 108 function to guide the robot
arm through a path of movement so as to provide service to the person on
the bed.
[0009]The intelligent bed robot according to the patented invention can
provide services, such as the support of the upper body and the carriage
of the meal shelf. However, there is a need for the provision of an
intelligent bed robot that is capable of performing gripping work, such
as the folding of bedclothes, in addition to existing services.
SUMMARY OF THE INVENTION
[0010]Accordingly, the present invention has been made keeping in mind the
above problems occurring in the prior art, and an object of the present
invention is to provide an intelligent bed robot in which one or more
grippers are attached to a supporting robot arm to enable the work of
picking up an object, thereby providing more familiar and convenient
services to a user.
[0011]In order to accomplish the above object, the present invention
provides an intelligent bed robot, including a pressure sensor-provided
mattress configured to monitor the position, posture and motion of a user
on a bed in real time, and assisting the user; an intelligent robot arm
configured to comprise vertical bars disposed on two opposite sides of
the bed and configured to have a predetermined length, a horizontal bar
configured to connect the vertical bars to each other, and torque sensors
disposed at lower ends of the vertical bar, and to measure horizontal and
vertical forces applied by the user; transfer rails configured to guide
the intelligent robot arm along a path of movement; and at least one
gripper coupled to the horizontal bar of the intelligent robot arm so
that it can move horizontally along the horizontal bar and rotate around
the horizontal bar, and provided with a finger unit capable of picking up
an object.
[0012]The intelligent bed robot may further include a control box for
reading pressure values of the pressure sensors by sequentially scanning
the pressure sensors using a multiplexer, and delivering data about the
pressure values to a main computer in a pressure measurement distribution
image form.
[0013]The robot arm may have two operation modes, including a follow mode,
in which the user can control the robot arm using his or her command so
as to obtain support means using the robot, and a support mode, in which
the user's body is secured and supported using the acquired support
means.
[0014]The follow mode may conduct work using a fuzzy network.
[0015]The horizontal bar may have a central separation element so that a
length of the horizontal bar can vary with relative locations of the
vertical bars.
[0016]The pressure sensor-provided mattress may monitor a person on a bed
using a Principal Component Analysis (PCA) algorithm, the PCA algorithm
performing a first step of determining a human's recognition target
pattern and relating pressure sensor dataset for pattern classification;
a second step of extracting feature points by calculating covariance of
the pressure sensor data; a third step of determining a number of feature
points capable of maximizing information classification between
respective pieces of pattern data; and a fourth step of performing
pattern recognition by comparing new incoming pressure sensor data with
predetermined feature points.
[0017]The robot arm may work in a command mode of conducting operations in
response to the user's command, which includes user's voice, and in an
automatic mode of conducting work according to a predetermined work
command.
[0018]The horizontal bar may have a ball screw disposed therein along a
length of the horizontal bar, and the gripper includes a first gear
structure provided with threads so that the first gear structure can
guide the gripper through linear movement in conjunction with the ball
screw; a second gear structure formed of a worm gear that works in
conjunction with the first gear structure so that the gripper can rotate
around the horizontal bar; and a third gear structure configured such
that the finger unit can conduct work of picking up an object.
[0019]The ball screw and the first gear structure may work in conjunction
with each other along a longitudinal hole that is formed along the length
of the horizontal bar.
[0020]The finger unit may have the shape of a human hand, include a
stationary first finger and a movable second finger, and perform the work
of gripping an object through overlapping of the first and second
fingers.
[0021]The first finger may be provided with an accommodation part so that
the first finger can accommodate the second finger when the first finger
and the second finger overlap each other.
[0022]The first finger and the second finger may have respective rubber
portions that come into contact with an object.
[0023]The intelligent bed robot may be controlled using a Controller Area
Network (CAN) device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024]The above and other objects, features and advantages of the present
invention will be more clearly understood from the following detailed
description taken in conjunction with the accompanying drawings, in
which:
[0025]FIG. 1 is a perspective view of a prior art intelligent bed robot;
[0026]FIG. 2 is a view showing a preferred embodiment of an intelligent
bed robot according to the present invention;
[0027]FIGS. 3A and 3B are a perspective view showing a gripper mounted on
the intelligent bed robot according to the present invention, and a view
showing the mounting of the gripper on the horizontal bar, respectively;
[0028]FIG. 4 is a perspective view showing an example in which grippers
are mounted on the robot arm of the intelligent bed robot according to
the present invention;
[0029]FIGS. 5A and 5B are enlarged p
hotos respectively showing the portion
of FIG. 4 in which the gripper is attached to the horizontal bar, and a
longitudinal hole which is formed along the horizontal bar;
[0030]FIGS. 6A and 6B show torque sensors that are attached to the
vertical bar;
[0031]FIGS. 7A and 7B show the different locations of the horizontal bar
and the vertical bars; and
[0032]FIG. 8 is a diagram showing the control system of the intelligent
bed robot according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033]The construction and operation of the present invention are
described in detail with reference to the accompanying drawings below.
The same reference numerals, shown in the respective drawings, designate
the same elements having the same functions.
[0034]FIG. 2 shows a preferred embodiment of an intelligent bed robot 200
according to the present invention. That is, FIG. 2 shows the intelligent
bed robot 200 equipped with grippers.
[0035]Referring to FIG. 2, the intelligent bed robot 200 according to the
present invention includes a mattress 204, an intelligent robot arm 202,
206 and 210, and transfer rails 208. In this case, pressure sensors are
attached to the mattress 204 so as to monitor the position, posture and
motion of a user 201 on a bed in real time and to assist him or her. The
mattress 204 needs to detect the intention of the user 201 when the user
201 lies down on the bed and then sits up, and to assist the user 201 in
sitting up using the triple folding structure of the intelligent bed
robot.
[0036]In the case where the user 201 uses an active guide system, it is
necessary to detect the position of the user 201. For this purpose,
14.times.24 pressure sensors are attached to the top surface of the
mattress of the bed. The pressure sensors have advantages over
temperature sensors or the like in that they have fast reaction speed and
high resolution. In this case, it is preferred that the intelligent bed
robot according to the present invention further include a control box,
so that the control box can sequentially scan the pressure sensors,
attached to the mattress, using a multiplexer, read the values of
selected pressure sensors, and deliver pressure value data to a main
computer in the form of a pressure measurement distribution image.
[0037]Furthermore, it is preferred that processors be attached to
respective sections so that hardware is not damaged when the shape of the
bed changes, since the bed has a triple folding structure. In this case,
construction can be made such that three sensing processors are attached
to the sections and transmit data to a main computer.
[0038]An algorithm capable of recognizing user information must be applied
to the mattress 204. In order to support stochastic real-time signal
processing, the Principal Component Analysis (PCA) algorithm is used as
the information processing algorithm. The PCA algorithm recognizes sensor
information from the bed in the form of images, and simultaneously
employs a filtering technique and a stochastic approach, which are
commonly used in image processing.
[0039]An algorithm with a small computational load is necessary because a
lot of noise is included in the input data provided by the sensors and
because the trajectory generation as well as the control of the robot arm
should be processed in real time. The work that must precede the
application of the present algorithm is data base construction for
classifying the incoming bed image input. Accordingly, a database
containing information about the positions and postures of the user on
the bed must be constructed. Meanwhile, a method of applying the PCA
algorithm to the present invention is described below.
[0040]First, the several primary pressure patterns of the mattress are
determined to perform pattern classification. That is, a recognition
target pattern, such as the lying posture and sitting posture of a human,
is determined, and then pressure sensor data are extracted.
[0041]Thereafter, feature points are extracted by calculating the
covariance of pressure sensor data. The feature points are used as
important information that is used to distinguish the patterns of
respective postures.
[0042]Thereafter, the number of feature points is determined such that
success rate of classification among respective pieces of pattern data
can be reached up to the predefined level.
[0043]Thereafter, pattern recognition is performed by comparing new
incoming pressure sensor data with the predetermined feature points.
Through this process, the current posture of the user can be determined,
and, using variation in the posture of the user based on recognition
results, motion information can be predicted.
[0044]The transfer rails 208 function to guide the robot arm 202, 206 and
210 through a path so as to provide service to a person on the bed.
[0045]The intelligent robot arm 202, 206 and 210 includes vertical bars
202(a) and 202(b) configured to have a predetermined length and placed on
two opposite sides of the bed, and a horizontal bar 206 configured to
connect the vertical bars 202(a) and 202(b) with each other. Torque
sensors are placed at respective lower ends of the vertical bars 202(a)
and 202(b) to measure the horizontal and vertical force applied by the
user (see FIGS. 5A and 5B).
[0046]One or more grippers 210(a) and 210(b) move horizontally along the
horizontal bar 206, and are mounted on the horizontal bar 206 so that
they can rotate around the horizontal bar 206. Furthermore, fingers 212
and 214 are included in the gripper 210 to grip an object. The gripper
210 may move along the horizontal bar 206 to the center of the bed, and
may move outside the mattress 204 when the gripper 210 is not necessary.
Furthermore, the gripper 210 can rotate 360.degree., so that it can
conduct the work of fetching a shelf from below the bed, or gripping,
spreading and removing bedclothes on the bed.
[0047]The working procedure of the gripper 210, for example, the procedure
of the work of folding bedclothes after a user has woken up, is described
below. In this case, the operation of the gripper 210 may be performed
both in an automatic mode and in a command mode.
[0048]In the case where a command mode is set, the user 201 issues a
command using voices or a bed manipulator. In this case, the current
position and posture of a patient are detected by the pressure sensors
attached to the mattress 204. Thereafter, the robot arm moves to a
location suitable for the posture and position of the user, and conducts
the work of folding bedclothes.
[0049]Meanwhile, in the case where an automatic mode is set, for example,
in the case where the user 201 wakes up and sits up on the bed, the
variation in the posture of the user 201 is detected by the sensors
attached to the mattress 204. In this case, the work of folding
bedclothes can be performed together with the control of the action of
moving the folding structure of the bed so as to conduct the work without
a separate command from the user.
[0050]In the work of the intelligent bed robot 200 of the present
invention in a command mode, a voice command or a command via the
manipulator is received, and then a service is provided. In this case,
the user 201 can issue a command, for example, to conduct the action of
preparing a meal or going out using a voice or a manipulator. At this
time, the user 201 does not issue commands for respective actions that
constitute a time series of actions, but transmits only higher control
commands (preparation of a meal, and preparation for going out) that are
classified according to category.
[0051]FIGS. 3A and 3B are a perspective view showing a gripper mounted on
the intelligent bed robot according to the present invention, and a view
showing the mounting of the gripper on the horizontal bar, respectively.
For the convenience of the user (201 shown in FIG. 2), the gripper 210 is
mounted on the horizontal bar to conduct the work of spreading or
removing bedclothes in addition to the work of conveying the shelf.
[0052]It is preferred that the gripper 210 include two fingers (a first
finger 214, and a second finger 212), in which case the first finger 214
is fastened, thereby preventing a joint from being bent when raising and
pulling a heavy object. The overall shape of the gripper 210 is curved to
be similar to that of a human hand, and thus can reduce the risk of
injury to the user (201 shown in FIG. 2) that may be caused upon
collision with the user.
[0053]It is preferred that the first finger 214 be provided with an
accommodation part so that the second finger 212 can pass through the
first finger 214 when the first finger 214 and the second finger 212
overlap each other. In this case, a path formed in the second finger 212
may be a through hole that passes through the second finger 212, or a
path that is formed by opening a side of the second finger 212, as
illustrated in FIG. 3A.
[0054]When the second finger 212 is maximally closed, the first finger 214
and the second finger 212 overlap each other. Through this overlapping
action, the size of a contact area can be increased for the case where
cloth, such as the cloth of bedclothes, is gripped. In this case, it is
preferred that the insides of the fingers be formed of rubber or the
like, thereby having great frictional force.
[0055]FIG. 3B shows the mounting of the gripper 210 on the horizontal bar
206. That is, FIG. 3B shows the mounting of the gripper 210 on the
horizontal bar 206 via gear structures.
[0056]The gripper 210 of the intelligent bed robot according to the
present invention includes first, second and third gear structures 217,
219, and 220.
[0057]The first gear structure 217 is provided with threads that are
engaged with a ball screw 209 mounted inside the horizontal bar 206 along
the length thereof, and that guide the gripper 210 through linear
movement. The second gear structure 219 is formed of a worm gear, which
works in conjunction with the first gear structure 217 to rotate around
the horizontal bar 206. The third gear structure 220 is configured such
that the fingers 212 and 214 can conduct the work of gripping an object.
Since the first gear structure 217 functions as a support when the second
gear structure 219 rotates, the first gear structure 217 does not rotate
around the horizontal bar 206, but guides the worm gear of the second
gear structure 219 through rotation.
[0058]Referring to FIGS. 3A and 3B, a first motor 215 is mounted in the
horizontal bar and provides driving force to the ball screw 209. The ball
screw 209, which receives driving force from the first motor 215, rotates
inside the horizontal bar 206, and the first gear structure 217 engages
with spiral threads and moves linearly along the horizontal bar 206. In
this case, the first gear structure 217 is provided with threads and thus
works in conjunction with the ball screw 209. Meanwhile, in the region
where the ball screw 209 is placed, the horizontal bar 206 has
longitudinal holes, so that the inside of the horizontal bar 206
communicates with the outside of the horizontal bar 206. Using the
above-described connection structure, the ball screw works in conjunction
with the first gear structure, so that the rotation of the first gear
structure 217 can be prevented. That is, the first gear structure 217
only moves linearly along the horizontal bar 206, does not rotate around
the horizontal bar 206, and functions as a support when the second gear
structure 219 rotates.
[0059]As shown in FIGS. 3 and 4, the second gear structure 219 has a worm
gear form, and, as the worm gear works in conjunction with the first gear
structure 217, the gripper 212 can rotate around the horizontal bar 206.
The reason why the second gear structure 219 has a worm gear form is that
an unnecessary motion can be prevented in a non-control state (an
unpowered state, etc.) because the gripper 212 undergoes high loads, for
example, while moving various objects.
[0060]The third gear structure 220 receives driving force from the third
motor 218, and functions to control the motions of the fingers 212 and
214 when the motion of picking up an object is performed.
[0061]The sensors attached to the mattress recognize the positional state
of the user on the bed, and the vertical bars (202 shown in FIG. 2) move
upon the performance of a necessary motion, in which case the moving
distances of the right and left vertical bars (202 shown in FIG. 2) may
not be the same (see FIG. 7B). According to the present invention, the
length of the horizontal bar (206 shown in FIG. 2) is automatically
changed in response to a change in the distance between the vertical bars
(202 shown in FIG. 2) based on the relative positions of the vertical
bars (202 shown in FIG. 2), which have moved. As an example, the
horizontal bar (206 shown in FIG. 2) may be configured such that the
length thereof can be automatically changed around a central separation
element (211 shown in FIG. 4) (see FIG. 4).
[0062]FIG. 4 shows an example in which grippers are mounted on the robot
arm of the intelligent bed robot according to the present invention. That
is, FIG. 4 is a perspective view showing parts of the vertical bars and
the horizontal bar equipped with the grippers.
[0063]From FIG. 4, it can be found that the present invention provides a
structure in which the vertical bar 202 is connected to both ends of the
horizontal bar 206 and the grippers 210 can move linearly along the
horizontal bar 206 and rotate around the horizontal bar 206.
[0064]FIGS. 5A and 5B are enlarged p
hotos showing the portion of FIG. 4,
in which a gripper 210 is attached to the horizontal bar 206, and a
longitudinal hole 206-1 or 206-2, which is formed in the horizontal bar
206 along the length thereof, respectively. Referring to FIGS. 5A and 5B,
the robot arm of the intelligent bed robot according to the present
invention has two grippers 210(a) and 210(b). Each of the grippers has 3
Degrees of Freedom (3 DOF). One degree of freedom is used to move along
the horizontal bar 206, another degree of freedom is used to rotate
around the horizontal bar 206, and the remaining degree of freedom is
used to control the work of picking up. In this case, respective degrees
of freedom are controlled by the first, second and third motors (215, 216
and 218 shown in FIGS. 3A and 3B), which have been described in
conjunction with FIGS. 3A and 3B.
[0065]Although the existing intelligent bed robots function to support the
body weight of users or to provide shelves for meals, the function of
picking up objects using one or more grippers is added to the intelligent
bed robot of the present invention, so that the intelligent bed robot of
the present invention actively assists a user in his or her physical
activities.
[0066]FIGS. 6A and 6B show torque sensors that are attached to the
vertical bar. Referring to FIG. 6A, a transfer platform, which enables
the robot arm to move across the entire area of the bed along the
transfer rails, is connected to the low end of a support bar, and two
Direct Current (DC) motors, which are installed on both sides of the bed,
drive the transfer platform.
[0067]Two torque sensors are attached to each transfer platform, and
measure horizontal and vertical forces that are applied to the vertical
bar by the user.
[0068]If the force applied to the vertical bar has only a horizontal
component f.sub.x, torques .tau..sub.A and .tau..sub.B, which are
measured by respective sensors, have the same direction. In contrast, the
vertical component f.sub.y of a force applied to the vertical bar causes
torques .tau..sub.A and .tau..sub.B, which are measured by respective
sensors, to have opposite directions.
[0069]The robot arm attached to the intelligent robot of the present
invention can operate both in a follow mode and in a support mode. A
follow mode is an operation mode in which a user can control the robot
arm using a command so as to secure a support means using the robot,
while a support mode is an operation mode in which a user fastens and
supports his or her body on the secured support means.
[0070]In the follow mode, a user can move the robot arm to a desired
position with reference to data detected by the above-described torque
sensors. In contrast, in the support mode, the body weight of the user
can be supported without the influence of data detected by the torque
sensors, so that the user can rest his or her body on a support means
that is provided by the robot arm.
[0071]As an example, when a user desires to change his or her posture on a
bed, how the follow mode and the support mode are performed is described
below.
[0072]First, a user locates the horizontal bar near his or her chest using
a voice command. In this case, the position of the user is detected by
the pressure sensors attached to the mattress, and the horizontal bar
moves to a location suitable for the user based on the results of the
detection (see FIGS. 7A and 7B).
[0073]However, the location of the horizontal bar based on a desired
position and the results of data measurement varies with the
characteristics of an individual user.
[0074]Accordingly, in the follow mode, the user can adjust the location
and height of the horizontal bar by pushing or pulling the horizontal bar
while holding it. In this case, the force applied to the horizontal bar
is detected by the torque sensors, and respective vertical bars are
moved. Finally, when the user is placed at a desired position, the
process may proceed to the support mode. The user may switch the
operation mode from the follow mode to the support mode using a voice
command.
[0075]In the support mode, the robot arm operates based on kinematics
control. The bed system estimates the position of the user, and then
controls the robot arm based on a scheduled path.
[0076]In contrast, in the follow mode, the user's intention is detected
through the torque sensors. Referring to FIGS. 6A and 6B, when the user
pushes or pulls the horizontal bar, the robot arm measures the vibrations
of the torque sensors, and then controls the motor A and the motor B.
After the user's intention has been detected through the torque sensors,
the position desired by the user is calculated with reference to the
combination of the measurement results of the torque sensor.
[0077]The torque sensors and the user's intention can be expected to be
intuitive, while the structure of the robot arm system is not easily
explained mathematically. Accordingly, it is preferable to use a fuzzy
network to find the user's intention. The following Table 1 and Table 2
are rule tables that are used for a fuzzy network, where P indicates
`positive`, N indicates `negative`, L indicates `large`, S indicates
`small`, and ZO indicates `zero`. Thus, the motor A and the motor B are
controlled according to the rule tables.
TABLE-US-00001
TABLE 1
.tau..sub.B
Motor A PL PS ZO NS NL
.tau..sub.A PL ZO ZO PS PL PL
PS ZO ZO PS PS PL
ZO NS NS ZO PS PS
NS NL NS NS ZO ZO
NL NL NL NS ZO ZO
TABLE-US-00002
TABLE 2
.tau..sub.B
Motor B PL PS ZO NS NL
.tau..sub.A PL PL PL PS ZO ZO
PS PL PS PS ZO ZO
ZO PS PS ZO NS NS
NS ZO ZO NS NS NL
NL ZO ZO NS NL NL
[0078]Using the Table 1 and Table 2, the robot arm can be moved to a
desired location through a simple computation using the signs and
intensities of signals.
[0079]FIGS. 7A and 7B show the different locations of the horizontal bar
and the vertical bars. FIGS. 7A and 7B show the comparison of the case
where the length of the horizontal bar is identical to that of the minor
axis of the bed with the case where the length of the horizontal bar is
longer than that of the minor axis of the bed.
[0080]The intelligent bed robot according to the present invention may be
implemented such that the length of the horizontal bar varies with the
relative locations of the vertical bars. When data is received from the
sensors attached to the mattress and the vertical bar moves to a location
suitable for the user, the length of the horizontal bar may vary with the
relative locations of the vertical bars. As results of the movement of
the robot arm based on the data measurement of the sensors, the length of
the horizontal bar is formed to be the shortest in the case of FIG. 7A,
while the length of the horizontal bar is formed to be longer than the
minor axis of the bed in the case of FIG. 7B.
[0081]FIG. 8 is a diagram showing the control system of the intelligent
bed robot according to the present invention.
[0082]The intelligent bed robot according to the present invention has 10
DC motors for operating the robot arm and 2 Alternating Current (AC)
motors for raising an object. Accordingly, it is preferred that the
control system be based on a Controller Area Network (CAN) to
simultaneously control the devices. Referring to FIG. 8, the 10 DC motors
installed in the vertical bar and the grippers are connected to the CAN,
and the 2 AC motors are controlled via RS232 using a microcontroller. The
microcontroller stores data that is detected by the pressure sensors
attached to the mattress.
[0083]The present invention provides an intelligent bed robot equipped
with one or more grippers, which analyzes the posture and action of a bed
user and is provided with a robot arm having multiple degrees of freedom.
[0084]Furthermore, the present invention provides an intelligent robot, in
which one or more grippers capable of picking up objects are added to a
conventional robot equipped with a pressure sensor-provided mattress and
a supporting robot arm, thereby providing more familiar and convenient
services to a user.
[0085]Moreover, the present invention provides an intelligent bed robot
that can be used to perform health monitoring and evaluate a
rehabilitation procedure.
[0086]Although the preferred embodiments of the present invention have
been disclosed for illustrative purposes, those skilled in the art will
appreciate that various modifications, additions and substitutions are
possible, without departing from the scope and spirit of the invention as
disclosed in the accompanying claims.
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