robot system type I and type II are developed, and the robots are performed ..... 5 The robot arm system is separated as another system installed on a desk.
WeP01-36
Proceedings of the 2005 IEEE 9th International Conference on Rehabilitation Robotics June 28 - July 1, 2005, Chicago, IL, USA
Development of Work Assistant Mobile Robot System for the Handicapped in a Real Manufacturing Environment Hyun Seok Hong, Sung-Yoon Jung, Jik-Han Jung, Byung-Gu Lee, Jung Won Kang, Dong-Jo Park and Myung Jin Chung, Member, IEEE
Abstract—We develop a work assistant mobile robot to help the handicapped. Mission statements for developing an assistant robot are derived based on survey to assist effectively the handicapped as many as possible in a real employment situation. According to the mission statements, work assistant mobile robot system type I and type II are developed, and the robots are performed user-trials by the disabled who is working in a manufacturing labor.
P
I. INTRODUCTION
works related to welfare service robotics have been mainly limited to the scope of assisting the disabled in their daily life or desktop vocational activities. Robot systems such as Intelligent Bed-Robot System [1] and Care Robot System [2] are designed to help the daily activities of the disabled in specialized indoor environment. Human-machine interface such as Eye Gaze Estimation System [3] is broadly developed to control the robot system easily. FRIEND [4] and KARES II [5] were wheelchair-based Rehabilitation Robotic Systems equipped with robot arm and designed to help the disabled to manipulate small objects such as food, drink, books and etc. However, it doesn’t seem that the disabled really feel happy by those robot systems which help their daily activities. It is important that humans feel self-confidence and happiness when they can live independently as one of the social members, not as burdens to the society. Therefore developing a vocational robotic system can realize the true meaning of the welfare. Although there were some vocational assistant robots, those were limited to office environment. The robot RAID [6], which is developed at Rehabilitation Engineering Research Center in Sweden, assists in picking out books from a bookshelf, bringing documents and serving drinks at office environment. The robot PROVAR [7] which is ordered using a speech recognition system also helps to process office works, for example, serving drinks, documents, diskettes, video tapes, and so on. And it displays the current situation of the robot through monitor. The robot, called as WALKY [8], can avoid obstacles while it maneuvers to bring things in laboratory environment. REVIOUS
The authors are with the Electrical Engineering and Computer Science department, Korea Advanced Institute of Science and Technology , Daejeon, Korea (e-mail: {wiser, syjung, jikhanjung, leebbgg, kctown99}@kaist.ac.kr, {djpark, mjchung}@ee.kaist.ac.kr; corresponding author to provide phone: +82-42-869-3429; fax: +82-42-869-3410).
0-7803-9003-2/05/$20.00 ©2005 IEEE
Derivation of mission statements
Development of robot systems
Understand user demographics
Define the function of the robot
Understand the employment condition
Design and Manufacture
Define the users and the tasks
User trials in real environment
Modify the robot systems
Fig. 1. Development architecture of work assistant robot system
However it has not been common to develop vocational robotic systems in a real manufacturing environment which most employers prefer the disabled to work. The objective of our research is to develop such a mobile robot system that assists disabled persons to work in a real manufacturing factory. The proposed robot systems are expected to assist disabled persons to satisfy their desire and capabilities so that to become productive members of the society. And we respect that it will result in the increase of the working population. Figure 1 describes the derivation of the mission statements and the development of the work assistant mobile robot system. II. DERIVATION OF MISSION STATEMENTS Our objective of developing robot systems is to assist the handicapped as many as possible in a real employment situation. In this paper, we categorized the survey results into three criteria, ‘A. to assist the handicapped as many as possible,’ ‘B. considering the real situation of employment for the handicapped’ and ‘C. to assist the most necessary part for the handicapped at work space’. A. Survey based on Criterion A In order to assist the handicapped as many as possible, we investigate types of the handicapped and their works in Korea. For this, we surveyed the data about the handicapped in Korea. To know the type of the handicapped, we cite the research results in [9], [10] and [11]. Among the total handicapped, 55.1% of the handicapped have the crippled disorder, 8.7% cerebral paralysis, 10.5% visual disorder, 8.8% hearing disorder, 0.8% speech disorder. On the other hand, people with internal organs impediment or mentally handicap are few. Figure 2 shows distribution of the disabled, and figure 3 describes disability distribution of people who have a crippled disorder or a cerebral paralysis. From the distributions, we can notice that the percentage of the handicapped who have the leg impediment is large. Figure 4 shows that most of engaged handicapped workers have
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Fig. 2. Types of handicapped persons Fig. 4. Vocational fields which the disabled want to be trained
Fig. 3. Distribution of crippled disorder and cerebral paralysis TABLE I DISTRIBUTION OF ACTUAL EMPLOYMENT FOR THE DISABLED Big Small Types of disorder workshop workshop Crippled disorder
82.0%
81.0%
Cerebral paralysis
0.2%
0.2%
Visual disorder
4.4%
3.1%
Hearing disorder
9.8%
6.2%
Speech disorder
1.2%
1.1%
Etc.
2.4%
8.4%
Fig. 5. Vocational fields which the employers want; ‘simple labor’ and ‘assembling using machine’ include assembling and classifying circuit parts, moving boxes, packing, delivering and cleaning up.
Companies with more than 300 employees are classified as a big workshop.
crippled disorder regardless of the scale of the workshop. As a summary, we can verify that the physically handicapped workers who have crippled disorder occupy the most. Therefore, it is desirable to develop the robot system assisting the handicapped workers who have crippled disorder. B. Survey based on Criterion B Considering the real situation of employment for the handicapped, we visited vocational education facilities1 and the companies2 which hire the handicapped. As shown in figure 4, our survey results describe that the physically handicapped people prefer computer-oriented jobs, for there are a lot of occupations in that field and these jobs require little spatial movement. According to the result, they are also interested in mechanical jobs. In the case of mechanical jobs, there are two reasons. One reason is that 1 Bundang branch of Korea Employment Promotion Agency for the Disabled and vocational schools in Daejeon and Ilsan. 2 11 factories including Mugunghwa Electronics and Immanuel Electronics which make mainly electronics, and Boram-Dongsan which mainly assembles the mechanical parts.
there are huge industrial demands and the other is that they can learn an expertise by these jobs. However, vocational fields which the employers want are mainly simple labor [12] as shown in figure 5. According to these investigations, there are huge gaps between occupations which the handicapped want and occupations which the companies need. As a result, although many social organizations give vocational education to the disabled, an actual employment situation makes the disabled mainly to do simple labor. Therefore, it is desirable to develop the assistant robot system to help the disabled to work in physical and simple labor such as assembling and classifying circuit parts, moving boxes, packing, and delivering. C. Survey based on Criterion C According to the report in [11], handicapped laborers feel difficult when they should carry heavy materials. Survey results also show that one who has the upper limb impediment wants the robot system to help him as his arm (fixing, loading, fine motion and so on). The person with the leg impediment hopes the system to substitute the function of his leg (movement, loading and so on) and those who have both impediments expects the system to help him when he should carry heavy materials. Target objects for transferring stuffs are divided into heavy one and light one3. In the case of the 3 By referring many boxes and bags used in a real factory, we defined the heavy one as (maximum size: 65×35×40cm, shape: box, maximum weight: 30kg), and light one as (maximum size: 30×25×10cm, shape: box or bag, maximum weight: 3kg).
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TABLE II SITUATIONS WHERE THE HANDICAPPED PERSON NEEDS A HELP Big Small Situations workplace workplace Transferring stuffs Move around in the workshop Operating machine Difficulty to understand the instructions Operating speed
55.4%
33.8%
14.5%
31.5%
27.9%
20.0%
24.4%
22.3%
20.0%
31.5%
Duplicated answers are permitted. Companies with more than 300 employees are classified as a big workshop.
fine motion task, the assistant robot system cooperates with human and supports the roller inserting task and the PCB inspection task. Therefore it is necessary to design the work assistant robot to transfer stuffs, to do some dexterous task and to move around freely. Here is our mission statement: work assistant mobile robot help the disabled who have lower limb(s) disability or upper limb disability, or lower limb(s) and upper limb disability to get a job in a manufacturing factory by doing physically simple labor.
connected to subsystems such as mobile platform, fork-lift system, robot arm system and the joystick controller. The joystick connection uses USB communication port of main computer, whereas others connections are through the RS232 port. Command data is composed of start byte, data bytes and end byte. The number of data bytes is the number of actuators in each subsystem. For example, a command data from the main system to the mobile platform has one start byte (eight bits), two data bytes and one end byte. Each data byte has the value between -125 and 125. Start byte value is 126, and the value of end byte is 127. This short data length speeds up the communication. The mobile platform is made up of a DSP controller and it has four emergency switches, ten ultrasonic sensors to detect obstacles in the rear, and two motors for movement and direction change. The fork-lift system has two actuators to fork and to lift objects. The robot arm system uses a MANUS arm. The mobile driving mechanism is common two-wheel driving mechanism. For user convenience, we adopt a rear monitoring system using a camera and a monitor. l
III. DEVELOPMENT OF ASSISTANT ROBOT SYSTEMS |
We developed two work assistant robot systems. Type I is focused on its versatility and the other work assistant robot system type II is mainly focused on its mobility. A. Work Assistant Mobile Robot System Type I 1) Define the function and design of the robot We suppose that a disabled person works sitting on a chair of work assistant mobile robot. Therefore the height of the robot chair should be designed lower than that of a desk. Furthermore the chair should be designed to rotate up to right angle to work at desk. When assembling parts are ran out or transferring stuffs are required, the person moves the robot and pick up and put down the stuffs. Therefore we adopt a fork-lift system in our robot system. When the robot moves around, the obstacle avoidance and alarm should work for safety. Basic concept of work assistant mobile robot system is described in figure 6.
Fig. 6. Basic concept of work assistant mobile robot system
2) Architecture of the assistant robot system We divided the work assistant mobile robot system into one main system and three subsystems according to their functions. Figure 7 shows each module configuration of our work assistant mobile robot system type I. The main system is a PC that runs RTAI-linux. It is
Main system
Joystick controller
Mobile platform
Forklift system
Robot arm system
k
mGGsG t
thu|zG
Fig. 7. Work Assistant Mobile Robot System Type I.
3) User-trials We had a series of user-trials of the developed working assistance mobile robot system with the participation of disabled persons who work in an actual manufacturing factory, ‘Boram-Dongsan’ and ‘Mugungwha Electronics’ in Korea. We have gathered their feedback about our work assistant mobile robot. The participants were randomly selected among factory workers who have lower-limb(s) or upper-limb impairments or lower-limb(s) and upper-limb impairments. Figure 8 is some pictures describing the user-trials of work assistant mobile robot system type I. B. Work Assistant Mobile Robot System Type II Through the user-trials of work assistant mobile robot system type I, we found some needs; (1) the robot arm system is hard to control, and needs to be smaller or needs to be installed on a work desk, (2) the mobile base and the radius of turning of the robot needs to be smaller and the chair needs to be rotated electrically and its height lower, (3) the fork of the fork-lift system needs to be smaller or to be folded electrically. With the improvements for these needs, we also developed work assistant mobile robot system type II. The basic function, control system architecture and the method of user-trials is basically the same. Therefore we describe the improvements only.
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(a) Moving stuffs - lifting up
(b) Moving stuffs - lifting down
(a) Transferring
(c) Working at desk (d) Moving around Fig. 8. User trials for Work Assistant Mobile Robot System Type I
(b) Moving around
(c) Working at desk (d) Moving stuffs Fig. 10. User trials for Work Assistant Mobile Robot System Type II
1) Define the function and design of the robot To make the robot with a smaller size and turning radius, we used omni-directional driving mechanism at cost of efficiency4and excluded the robot arm subsystem5. We also adopted revolving chair and foldable fork controlled by motors and arranged the fork-lift system in the rear side. 2) Architecture of the assistant robot system
ACKNOWLEDGMENT This research was supported by the Human-friendly Welfare Robot System Engineering Research Center (HWRS-ERC) of Korea Advanced Institute of Science and Technology (KAIST). REFERENCES
l
|
Main system
Joystick controller
Mobile platform
Forklift system
k
yG G
[1]
mGGsG
Fig. 9. Work Assistant Mobile Robot System Type II
3) User-trials Among the enhancements of the work assistant mobile robot system type II, many users applaud the omni-directional mechanism because of its easiness to control. Figure 10 shows the pictures of the user-trials. IV. CONCLUSION Work assistant robot system type I and II have been developed for the vocational use in real manufacturing factories. The developed robots were tested with the participation of handicapped people performing tasks such as moving boxes from a table to warehouse, assembling and so on. It has been verified by the user-trials and feedbacks that the proposed work assistant robot is capable of assisting a disabled person to work in a manufacturing environment as a normal person would perform. Further study should be carried out to make our robot more convenient to operate and to make it smaller in size. 4 Omni-directional driving mechanism makes more friction forces than two-wheel driving mechanism. 5 The robot arm system is separated as another system installed on a desk.
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