Integrated System Build & Test
Table of Contents
Team Vision for Integrated System Build & Test Phase
- Finalize shoulder and hip designs
- Start system integration testing
- Waterproof leg servos and begin in-water testing
- Finalized full body assembly
- Full system integration on land
- Partial system testing in the water (Tail system tested)
- Leg servo waterproofing still in progress but nearing the end
Test Results Summary
Tail System Prototype and Testing
Leg System Prototype and TestingThe hardware for the leg connections were updated so the the legs are sturdy enough to hold their own weight and it can successfully walk across the table. The roller blade axles were also implemented for more robust and smooth motion. While testing, we realized that the legs need to start in a certain position or they will just collapse as seen in the picture below. This will be fixed with a hard stop added to one of the leg segments. Limit switches will also be added in order for the robot to automatically set the gait before startup.
Hips and Spine Assembly
Velcro will connect the hips and shoulders to prevent bowing and increase overall support.
WaterproofingInitial Silicone Adhesive was not sufficient for waterproofing the motors Air was noticeably escaping
- Possible Cause - Silicone was old and never fully hardened
Secondary method is to coat the motor body with Flex Seal in order to seal off any potential point of entry for the water. Two full coats were needed with emphasis around where the wires pass through the motor body.
Current Status - 3 motors passed short-term underwater performance test. Long term underwater test has not been performed yet
- 1 motor seems to have locked up at some point during the process and is not even able to me moved manually.
- Had already planned to order backup motors
For the electronics box, we have picked out a 19 pin connector that is rated IP68/69K. The seal seems to be very secure for long term submergence and the plastic is overmolded to help stay more secure. We have not yet drilled through the box and installed the connector but plan to in the next week or so.
Risk and Problem TrackingChanges to our Risk Assessment for this phase include:
A working copy of our risk assessment can be found here.
The problems that we ran into during this phase and our solutions can be found in the above sections.
Functional Demo MaterialsOur Week 6 Functional Demo presentation can be found here.
Notes and actions items from the demo can be found here.
Bill of Materials
Our Bill of Materials can be found here: Bill of Materials
Plans for next phase
- Buoyancy testing
- Drill the hole for the electronics box connector
- Test full body swimming performance
- Test battery life with whole system
- Design and building Imagine exhibit
- Integrate limit switches for gait regulation
- Design head and aesthetic additions
- Poster/Technical Paper/Lightning Talk
A working copy of our project plan can be found here.