Mechatronic Anti-Tremor System (MATS)

This project was for 24-671: Electromechanical Systems Design with Professor Mark Bedillion

For our Senior Design Capstone Project, we set out to design a device that will enhance the quality of life of Parkinson's Disease (PD) Patients, specifically by addressing micrographia (difficulty of writing due to hand tremors).  In the ideation stage, we converged on the idea of a pen grip that will be able to sense and counteract tremors.  Within our team of 5, we split into subgroups to work on enclosure design and controls.

We designed and fabricated a series of prototypes:

• Tremor Generator: Because we did not have the opportunity to work directly with PD patients, we created our own generator that simulates tremors of different characteristic frequencies between 4-6.4 Hz.
• Tremor Sensor: We built a sensing system to test that we can pick up tremors accurately and at a sufficient sampling rate.  Later, it was integrated into the Anti-Tremor Generator.
• Anti-Tremor Generator: A device that can sense tremors and produce torques to stabilize the hand.

Poster :

mats_poster.pdf
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My main focus for this project was working on the control system.  The goals for designing the controller were stability and minimal error.  We decided to implement the Repetitive Controller based on the Internal Model Principle.  Matlab was used for the controller design: Simulink and Root Locus Plots.  The FFT Plot illustrates that the controller is able to send out signals to cancel out tremors at peak frequency.

Testing

Unfortunately, the device did not work as we had planned. The issue was our incorrect assumption of the system dynamics. We presumed that the rotation in the wrist and hand can be mostly dampened by a single rotating motor. This idea was proven to be achievable in a computer simulation, as presented by the results of the Simulink Model. However, we ran into problems during system integration, where we were getting unwanted vibrations in other degrees of freedom. Although the motor behaved as wanted (as commanded by the IMP Controller), and moved in the general direction in an attempt to counteract the tremors, it unfortunately introduced torques in other axes.

However, along the way, we learned about many things! :

• The Design Process, from concept generation and selection to system integration
• Project Planning
• Selecting and Purchasing parts
• Custom Part Design/Manufacturing/Assembly
• Discovering & Resolving Unexpected Challenges
• Team-Working !

At the end of the semester, we presented our project at the Senior Capstone Design Expo.
View photos of the Expo here :
https://www.facebook.com/media/set/?set=a.10156370558994438.1073741846.610249437&type=1&l=8dcfdcb5a5

Team Members ( L -> R ) : 
Rinko Maeshima
Jason Seepaul
Ben Warwick
Natha Singhasaneh
Camilla Xu

Lastly, we would like to thank the course staff for their tremendous help and support!