1. College of Engineering and Applied Sciences
Motion Control of Robot for passive rehabilitation of human shoulder
Presented by
Md Rasedul Islam
PhD Student
Mechanical Engineering Department
Mechanical Engineering Department

2. American Heart Association reports Mechanical Engineering Department
College of Engineering and Applied Sciences
American Heart Association reports
Approximately 785,000 persons experiences a new or recurrent cerebral vascular accident (CVA) in US
Among which people experience mobility impairment
Having difficulty doing ADLs (Reaching, Gripping, Touching etc)
It is essential to restore motor function in order to perform ADL and return the domestic and social life
Task specific Repetitive therapy program help regain lost mobility
Limited number of health professionals
Incorporation of robots in rehabilitation started back in early 1990s
Mechanical Engineering Department

3. Robots in Rehabilitation Mechanical Engineering Department
College of Engineering and Applied Sciences
Robots in Rehabilitation
Robots have the potentiality in rehabilitation programs.
Incorporation of robots in rehabilitation started back in early 1990s.
Two types end-effector type (MIT-Manus) and exoskeleton type (Armin-III)
In this project, a robotic device for shoulder rehabilitation were designed and controlled.
Mechanical Engineering Department

4. Mechanical Engineering Department
College of Engineering and Applied Sciences
Range of movements
The table shows the range of movement and adopted from winter (2008). The current robots has 3 DOF with wider range of motion
Shoulder
Joint
Types of Motion
Range
Joint 1
Abduction
180
Adduction
-50°
Joint 2
Vertical Flexion
180°
Vertical Extension
Joint 3
Internal Rotation
-90°
External Rotation
90°
Mechanical Engineering Department

5. Mechanical Engineering Department
College of Engineering and Applied Sciences
Kinematic Model
Table-2: Modified Denavit-Hartenberg parameters
Joint (i)
αi-1
ai-1 di θi 1 θ1 2
90° θ2 3 L2 θ3
Figure: Link-Frame assignment
Mechanical Engineering Department

6. Mechanical Engineering Department
College of Engineering and Applied Sciences
Control
A non linear computed torque control technique was used to control the robot
Figure: Control Architecture
Mechanical Engineering Department

7. Mechanical Engineering Department
College of Engineering and Applied Sciences
Simulation
To evaluate the performance of developed control technique, simulation was run to see the trajectory tracking of each joint movement.
Figure: Simulation result
Mechanical Engineering Department

8. Simulation (Continued) Mechanical Engineering Department
College of Engineering and Applied Sciences
Simulation (Continued)
The above graphs plotted from simulated results show comparison of measured trajectory (outcome of simulation) with desired trajectory (given), error and required torque as well.
The measured trajectory is almost overlapped the given trajectory (Plot of angle against time).
The error (difference between reference and given trajectory) is lower than 0.05° that shows the efficacy of controller (Plot of error against time).
The control is robust enough to handle the Nosie.
Mechanical Engineering Department

9. Mechanical Engineering Department
College of Engineering and Applied Sciences
Future Works
Our ultimate goal is to develop a whole arm wearable exoskeleton for supper limb rehabilitation.
The proposed exoskeleton would be smart and intelligent.
It would have a fine and adaptive controller.
The control with EMG and signal would be incorporated in the controller.
Mechanical Engineering Department

10. Mechanical Engineering Department
College of Engineering and Applied Sciences
Thanks
Mechanical Engineering Department

11. Mechanical Engineering Department
College of Engineering and Applied Sciences
References
Mozaffarian, D., Benjamin, E.J., Go, A.S., Arnett, D.K (2015). "Heart disease and stroke statistics—2015 update: a report from the American Heart Association". American Heart Association. Circulation. 2015;131:e29–e322
Heidenreich, P., Trogdon, J (2011). "Forecasting the Future of Cardiovascular Disease: A Policy Statement from the American Heart Association. Circulation" Circulation ;123:
Craig, John J. Introduction to Robotics: Mechanics and Control. Noida, India: Dorling Kindersley (India) Pvt. Ltd, Print.
4. Pons JL, ed. Wearable robots: biomechatronic exoskeletons, vol Hoboken, NJ: Wiley;
Mechanical Engineering Department