1. About a Part of EHA (1)
I'm EHA team member Jang won. I will start the presentation. this is team member.

2. Context Apparatus in EHA - Servo motor part
AC servo motor - Specification - Why choose?
servo driver - Function - Specification
History log
Reference
Q & A
Today, I will discuss about the motor of EHA system. Our team already choose one motor and the driver. I will explain the motor and driver

3. Apparatus in EHA accumulator Relief valve pump Piston motor
Hydraulic circuit of EHA prototype
pump
Piston
motor
Check valve
This picture shows the diagram of EHA system. We show you this in last presentation
The mechanism is like this. The motor controls and drives the pump. When the pump operates the piston will move according to the rotation in clockwise circle or reverse circle. The relief valve, check valve and the accumulator limit the pressure of fluids.
we focus on explaining the specification of the motor in EHA system.
LVDT(The linear variable differential transformer)
LVDT

4. AC servo motor : HMA8-04AAA1
- Specification
First I will show you the motor we selected. This is AC servo motor. Model HMA8-04AAA1 is made in the corporation CS CAM. The specification of this will be claimed one by one. Rated output is 400W. Rated output means the output steadily operates when provided power. But if the output exceed the 400W the system will not adequately operate. And the other characteristics that have the word ‘rated’ - the red box in table is also steadily operating condition.
AC SERVO MOTOR
TYPE
HMA8-04AAA1
rated output
400W
rated torque
1.27Nm
rotative velocity
3000rpm
rated current
2.8Arms
the rate of torque to current
0.498 Nm/A
input voltage
200V

5. AC servo motor : HMA8-04AAA1
- Why use this motor?
Low cost - expensive motor is not needed for research
Small Size
- output is low but easy to control and experiment
The motor we chosen have two merits. It’s low cost and we don’t need too expensive one.
And because it is small size it is easy to control the system and experiment

6. AC servo driver : HD-04AAA
- Function
1. Receive command signal from control system and amplify the signal.
2. Transmit the signal to motor and the command signal represents a desired velocity ,torque and position
3. Correct for any deviation between the commanded status and actual motor status
AC servo driver also needs to control the motor. A servo drive receives a command signal from a control system, amplifies the signal, and transmits electric current to a servo motor in order to produce motion proportional to the command signal. Typically the command signal represents a desired velocity, but can also represent a desired torque or position.
A sensor attached to the servo motor reports the motor's actual status back to the servo drive. The servo drive then compares the actual motor status with the commanded motor status. It then alters the voltage frequency or pulse width to the motor so as to correct for any deviation from the commanded status.
In later

7. AC servo driver : HD-04AAA
- Specification
The specification is really complicated. But in redbox the command signal might be -10~10V. By using this signal, we can control both the velocity and torque of the motor and piston moving. Because the modifying the hardware is so difficult, our team will only use the input voltage and control torque and velocity

8. History Log Chart 9/02 Decision of the subject 9/04
Finding the paper related with EHA system
9/05
Discuss about paper & Meeting with Professor
9/11
Discuss about paper
9/12~9/14
Preparing for Presentation
9/16
Decision of the subject of next presentation
9/18
Finding patents related with EHA system
9/19
Discuss about script & Meeting with Professor
9/20
Discuss about papers and patents, checking our presentation
9/23~9/24
Discuss about motors & Meeting with Professor
9/26~9/27

9. Reference
S. H. Park “Characteristics of an Electro Hydrostatic Actuator and Application Fields” 유공압시스템학회지 제6권 제1호 pp. 2~ 년 3월
S. H. Park, “A Study on Control of Electro-Hydraulic Servo System Using High Speed Solenoid Valve,” Dept. of Mechanical and precision Engineering Gradate School Pusan National University, Feb, 1996.
김종식, “선형 제어시스템 공학” 淸文, 2005.
Y. H. Park, S. H. Park “EHA(Electro-Hydrostatic Actuator) Identification and control of Position Control System for Electro-Hydraulic Actuator” 한국동력기계공학회지 제15권 제2호 pp.69~ 년 4월
Automatic Control Systems (9 New, Hardcover)
Patent Material
▪ 유체압 실린더 장치, 출원번호 특개 (일본특허)
▪ 전기유압 액츄에이터, 출원번호 특개 (일본특허)
▪ 유압 편로드 실린더를 구비한 산업용 전기유압 일체형 구동기 시스템, 출원번호
▪ 산업용 전기유압 일체형 구동기 시스템의 성능 및 효율 개선을 위한 제어방법, 출원번허
▪ 전기 유압 하이브리드 액츄에이터, 출원번호
▪ 자동변속기용 유압제어 시스템, 출원번호 특
▪ 유압제어 시스템, 출원번호 (국제특허)
▪ 전동식 오일펌프의 유압제어장치 및 방법, 출원번호 (국제특허)
▪ 전압제어회로, 출원번호 (국제특허)
(7) 리쯔밍, 이지민, 박성환, 김종식, 박용호, “전기 정유압 구동기를 적용한 유압식 동력 조향 시스템”,한국동력기계공학회지 15권 6호 86 ~ 94 페이지
(8) 이지민, 박성환, 박민규, 김종식,”적응PID 슬라이딩 모드 제어기법을 적용한 EHA 시스템의 위치제어(A Position Control of EHA Systems using Adaptive PID Sliding Mode Control Scheme), 한국동력기계공학회지 17권 4호 120 ~ 130 페이지
(9) Min Gyu Park. Sung Hwan Park, Jong Shik Kim, Ho Gil Lee “Modeling and Control and Electro Hydrostatic Actuator Systems” 2009년 8월 pp

10. Question