P17027: Starfish Gripper

Integrated System Build & Test with Customer Demo

Table of Contents

Team Vision for System Level Demo with Customer

To Complete:


System Integration Results

Belt Drive System

Components were received later than expected, causing a slight delay, but once received the system was assembled without major issues.
Modified pulley attached to servohorn and shaft

Modified pulley attached to servohorn and shaft

Single side view of installed belt drive system

Single side view of installed belt drive system

Below is a link to a video of a successful test of the extension mechanism and belt drive system above water.

Extension Mechanism & Belt Drive - Video

Electronic System

All wiring and soldering was completed and tested. All systems are functional.

Working on finalizing wiring

Working on finalizing wiring


The team spent a good portion of the phase troubleshooting the waterproofing of the electronics enclosure. In particular, the port which all the electronic wiring goes through was a pain point. A fair amount of epoxy was applied to the wiring on the inside of the container, but in testing, water was still able to enter between wires or weak points.

A syringe and needle were then used to inject epoxy in between and around wires within the port, which was much more successful.

Epoxied cable port with a small droplet of water coming through

Epoxied cable port with a small droplet of water coming through

Test Results Summary

Links to updated test plans as of 4/12/17:

Deployable Depth Test Plan

Life Cycle Test Plan

Object Capture Rate Test Plan

All testing is planned to be performed April 17-21.

Issues Encountered

Pressure Sensor Failure

The pressure sensor had been tested and implemented into the system to prevent over pressurization of the soft actuators. During testing the robot under the water, the pressure sensor had stop reading the value. There are two possible reasons to make sensor stopping working, first during the test under the water, the electrical part inside the sensor had been contact with water. Second reason could be the power issue, the sensor could received more than 3.3V from any sources such as Arduino or Vin which from battery, the sensor only work at 3.3V anything above that voltage will make sensor burn out and stop working. the first sensor had been replaced by the new sensor however during the process of waterproofing, Marine Epoxy had been contact into the surface of the sensor, team was tried to clean and replace the old surface the sensor by silicon which hoping it's working and waterproofing as well but it didn't work out.So due the depth of the robot will be exposed to, the team will not be using pressure sensor underwater.

Servo and Extension Mechanism

During our phase review, the Hitec servo motor stopped working. The cause is presumed to be that it was being operated over the rated voltage. A replacement servo motor was purchased from the RIT Construct, but this servo was not rated for waterproofing and was not as high quality as the Hitec motor. This servo was installed into the waterproof servo enclosure with some slight modifications and is operational. However, it does not provide enough torque to drive the extension mechanism. It did operate successfully a few times, as shown at the beginning of the linked video below, but did not operate reliably over a number of extensions.

YouTube - P17027 Starfish Gripper - RIT MSD

Problem Tracking

public/Integrated System Build and Test Documents/ProblemTracking_IntegratedSystem.PNG

Plans for next phase

Individual Plans

Individual 3 Week Plans - Customer Handoff & Final Documentation

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