Robot Hand

Team: Benjamin Ginnett

Project

  • Functional Prosthetics allow disabled people to gain control of prosthetic limbs, but the often cost thousands to tens of thousands of dollars.
  • Muscle sensors, 3d filament, microcontrollers, and servos do not cost thousands of dollars.
  • Our Goal: create a functional “hand” that costs less than $200, is capable of executing the user’s desired movement with little to no delay, and can grasp and hold an object in place.
  • Functional prosthetics will become more and more functional with time, cheap alternatives should begin entering the market.

System

System Diagram

Methods

little diagram of strong and weak flexion
  • The Myoware 2.0 reads the muscle signal and sends it to the STM32
  • The STM32 samples the data with the ADC sent to DMA. This signal is then sent through UART to a computer to be graphed live.
  • The same hex value signal is convered into servo duty cycle values. PWM signals are then sent to multiple timer channels.
  • We 3d printed a hand that we designed to mimic a simplified human hand.
  • We use a lithium ion battery with buck converters to power the STM32 and the servos without frying any components.

Conclusion

  • The project works. The sensor allows the user to control the hand with ease. The hand was capable of holding and grasping objects.
  • We proved that you can create functionality with less than $200. Further refinement could result in full control for a full prosthesis.
  • The next steps would be to increase control by adding more sensors and more complex logic.
  • This project taught us a lot about embedded programming. It firmly cemented a lot of ideas, and we spent a lot of time in the STM32 user guide and embedded textbook.
  • We learned a great deal about modeling and 3d printing.