Spring 2017 Prosthetic Arm: Kill Switch Test
The Robot Company | CEO Professor Gary Hill
Blog Post created by Project Manager | Bianca Esquivel
Project Test Executed by Mission, Systems, and Test Engineer | Phuong Tran and Electronics and Control Engineer | Mikael Movsisyan
Table of Contents
Preliminary Information
Test Objective
An ON/OFF switch is needed for any electronic system. A concern about implementing an ON/OFF switch for the prosthetic limb design was the surge current when turning the switch on and off. We performed this test to determine if our switch can withstand the current going through it and if the spiked current will destroy the other electrical components of the prosthetic limb.
This experiment is performed in response to requirement
L2.4.2 – The Prosthetic Arm shall implement an electronic kill switch to shut down all operation in case of emergency as determined by the user.
Problem: We will try to confirm that a switch on the V- path back to battery is able to turn off the prosthetic arm and hand system without damaging other electronic components
Materials
Arduino Uno
Servo
Light sensor
Switch
9V Battery
Test Set Up
Step 1: Assemble the components as schematic shown with switch in the “ON” state [Fig. 1]
Step 2: Command Arduino to turn on all electronic components
Step 3: Turn off the switch
Step 4: Turn on the switch and examine if other electronic components are not broken [Fig. 2]
Step 5: Turn off and on the switch for 3 times
Results
All electronic components are not damaged by turning the switch off abruptly. Hence, we can incorporate this in the prosthetic arm design for the kill switch.
Conclusion
Since the use of the kill switch doesn’t put any of the electrical components in danger malfunction, this means we can fulfill our safety requirement for the prosthetic arm and use this kill switch as part of the design.