Team 22 - Haptic Shoulder for Physical Human Robot Interaction

Individual Component Reports

High Range Mechanical

by Calvin Joyce

Investigation of various mechanical designs that provide a high range of motion.

The shoulder has a high range of motion, and there are limited mechanical designs that can reach a similar range of motion. In addition, we have a restriction of only utilizing a single joint center which limits our options of mechanical systems.

The main objectives of the report are:

Understand how mechanical joints work
- Become familiar with the motion and limitations of different types of joints
Understand how single vs. multiple degree-of-freedom systems work
- Understand complexities and limitations

PDF | GOOGLE DOC

Shoulder Anatomy

By Isabella Fiorini

Investigation of the anatomy of the human shoulder, its motion, its limitations, and common injuries.

The shoulder is the second most mobile joint in the human body, and because it is one of the most mobile, it is also one of the most complex joints in our bodies. Understanding how the shoulder works is a crucial portion of this project as the team had the objective of designing and building a model capable of simulating the shoulder's range of motion (ROM) and resistance.

The main objectives of the report are:

Understand how the human shoulder works
- Become familiar with the overall anatomy of the shoulder and understand the functionality of its different components
Understand the human shoulder’s biomechanics
- Define the ROM of an average human shoulder and understand how it varies from person to person
Understand how a shoulder is injured
- Understand the most common forms of shoulder injury and their sources
- Understand the care that needs to be taken when maneuvering a human shoulder to avoid injury

PDF | GOOGLE DOC

Force-Feedback Control

By Rizzi Galibut

Research in the implementation of force-feedback control to simulate the resistive forces in the human shoulder.

The human shoulder produces resistive forces during its end range-of-motion due to the range limitations of the joint. The resistance produced in the shoulder is proportional to the force being applied to it. Since this resistance changes with displacement, it's important to implement a control loop that can account for the variable force input and torque output.

The main objectives of the report are:

Understand how feedback control works
- Become familiar with control terminology and processes
Understand how force-feedback is used in robotics
- Define haptics vs. force-feedback
Understand how to produce variable resistive torque
- Understand how motor torque and current relate to stiffness

PDF |GOOGLE DOC

Sensors

By Roger Nguyen

Research in various methods that electromechanical systems use to perceive and process environmental information.

Sensors are important to determining the location of the upper arm. In a human shoulder, stiffness occurs when the upper arm reaches its end range-of-motion. To determine when this occurs in our shoulder model, position sensors are necessary to accurately sense and log the location of the upper arm.

The main objectives of the report are:

Understand why sensing is important
- Understand how electronic systems collect information
Understand how different sensors work
- Define physics of sensors and encoders

PDF |GOOGLE DOC

Variable Stiffness Mechanisms

By Tarun Murugesan

Research in various methods of applying variable resistance (stiffness) without the use of closed-loop feedback.

Mechanisms that enable tuning of an output stiffness are especially useful in robotics applications that demand adaptability to unpredictable situations. For the purpose of our project, this "variable stiffness" is essential in order to model the shoulder stiffness unique to all individuals. This study was conducted in order to explore solutions that do not require closed-loop feedback via motors due to their potential complexity.