P18045: Tremor Mitigation Test Arm
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Customer Handoff & Final Project Documentation

Table of Contents

Team Vision for Final Demo and Handoff

During this Phase, our team planned to:

What Our Team Accomplished:

Electrical Subsystem Updates

Slow Motion Testing Mosfets with Changing Direction

Slow Motion Testing Mosfets with Changing Direction

Plastic covers were 3D printed to conceal and protect loose wiring. The CAD of these pieces can be seen below:

CAD of Power Supply Covers

CAD of Power Supply Covers

What Happened Electrically

So, our electrical subsystem was unable to support the existing mechanical subsystem. Due to two blown out motor modules. The failure mode is still a mystery, but an educated guess could be made that a wrongly soldered wire allowed extra power into Brake and Direction terminal points.

The use of MOSFETs was unnecessary since the Anaheim Automation MDC100-050101 Motor Controller has built in Transistor–Transistor Logic (TTL), meaning that the Arduino can directly control the Brake and Direction pins with an analog output without the use of MOSFETs. However the MOSFETs were actually used to invert the logic required to drive the motors. For example since when grounding the Brake to the Ground pin would have switched on the device with a logic 0 input this can be undesirable since it would make more sense for the motors to turn on during a logic high event. The MOSFETs were used to correct this and allow the allow the Arduino to directly control when the motor drivers turned on, instead of assuming that from when the power supply is plugged in the pin wouldn’t automatically be grounded switching on the motors on undesirably. Just something to consider going forward. Electro-mechanically the system should work as expected, but with putting two systems there will always be problem solving efforts. Therefore, it can only be speculated from the limited testing using the sample Arduino code (actuating the motor back and forth), after a few minutes the motors were hot to the touch. Heat should be a major concern if the motor incorporates a back and forth motion.

Arduino Troubleshooting

After the motor controllers broke, we wanted to make sure that the Arduino was still in good shape. We tested this using an oscilloscope to make sure that the Arduino was still outputting 5 V for all pins. The results can be seen below.
Arduio Test

Arduio Test

Test Results Summary

Unfortunately after the motor controllers stopped working, we were unable to complete any electrically involved tests. However, we were able to complete all mechanical tests.

Test Results Completed:

Test Plans/Results document can be found here.

Risk and Problem Tracking

Risk Management

Risk Management

Problem Tracking

Problem Tracking

Final Project Documentation

Final Product

Final Product

Here are the links to the Technical Paper and Poster.

Project Management Design Tools Design Documentation Validation & Presentation

PRP

Requirements

Schedule

Cost

Risk Management

Problem Management

Communication & Minutes

Use Cases

Benchmarking

Functional Decomposition

Morphological Chart

Pugh Concept Selection

BOM

Mechanical Drawings

Electronic Schematics

Software Code

Manufacturing Instructions

Test Plans/Results

Simulations

Phase Review Documents

Technical Paper

Poster

Imagine RIT Exhibit

Future Improvements

Using a one directional driving motor would be a better design, there would be less heat and less vibratory motion to deal with. This would extend the longevity of both the motor drivers and the motors. But due to time and size restraints the more simplified, less thought out design decision was made. A word of warning Anaheim Automation technical support has been unhelpful in providing data and overall troubleshooting. Using the single direction drive approach, the controls would be based upon changing the speed of the motor via the motor driver’s external potentiometer output. I have provided sample code on edge for connecting the Arduino to MATLAB if you decide to take that approach. Which from a controls standpoint using Simulink in conjunction with Arduino, MATLAB, and Simulink should provide a cost-effective solution for controlling the test arm. A sample controls Simulink file will also be added to EDGE for reference. But at this point it is our understanding that a closed loop feedback using the nine degree-of-freedom (DOF) sensor will be the best way to control the test arm.

The use of capstans is a good idea for connecting the pulleys rather than a single string because the increased friction between the pulley and string will cause less slip. Capstans operate according to the equation seen above and improves the slip exponentially with each time the ‘rope’ wraps around.

Summary Points are Below:

Our summary document can be found here

Functional Demo Materials

Include links to:

Plans for Wrap-up

Individual Plans


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