Team Vision for Build & Test Prep Phase
Our goals for this first phase of MSD ll were to review where we left off at the end of last semester and finish the tasks we did not complete during MSD l. This was accomplished through the following tasks that we planned to do during this phase:
- Review tasks which were left unfinished at the end of MSD l (exterior casing design, feedback system)
- Make a second large purchase
- Update CAD and design drawings for the exterior casing of SailBot
- Build a test-bench modeled after the back of a sonar
- Determine test plans for next phase
Our team accomplished the following:
- Reviewed the donations received over the break from new sponsors and sent follow up thank you emails
- Sent out a second large purchase order for remaining electrical and some mechanical parts
- Updated BOM to reflect the purchase and new budget
- Updated designs for the exterior casing of SailBot
- Began testing electrical subsystems
- Updated test plans, risks and problem tracking
Team Design Updates
Based on last semesters gate review, the biggest concern was an aesthetic, weather-durable out shell. After collaborating between industrial and mechanical subteam. The overall shape of SailBot was redesigned.
Sketch of SailBot redesign
The new design gave SailBot curved edges to match the style of a boat. A ridge was added halfway to give users a comfortable carrying method. The design was then incorporated into SailBot geometry to prepare for manufacturing.
SailBot's new design: closed, Battery door open, and repair door open.
SailBot has two compartments that can open, a batter case, and a maintenance hatch. The battery case is sealed with magnets and allows the instructor to switch batteries and store the secondary joystick without exposing the rest of SailBot's insides to water.in this hatch, there is a fastener that can open the repair door, giving a user access to all the internals if they need to fix, or upgrade any parts on SailBot. The magnets from the door eliminate the use for outside fastening material to give the device a "cleaner" look.
The outside of SailBot will be covered in fiberglass to match the aesthetic of the boat. This will also endure the weather and sun exposure that could have possibly damaged the outside. In order to mount the fiberglass nicely, 3D printed molds will slide into the 80/20 frame that the fiberglass coating can wrap on. 1/8" Lexan will be fastened between the 3D printed molds to give the fiberglass some structure and stability.
Example of how the Fiberglass (white), lexan (clear), and 3D printed mold (red) will cover the device
Test Plan Summary
The preliminary test plans from last phase were updated and expanded upon to include each subsystem of SailBot. All customer requirements, engineering requirements and risks were taken into consideration when creating these plans and each is addressed at least once. Specifications and metrics for the target and ideal test results will be finalized in the next phase as testing begins. Effectiveness of each test will also be assessed to ensure the results and conclusions from them accurately satisfy the requirements. A list of the tests and their purposes is shown below:
- Force Test - Simulate the forces of water acting on the tiller. Test durability and functionality of the tiller movement subsystem
- Battery Test - Ensure SailBot can perform for an entire sailing session. Testing durability and battery life.
- Water Test - Ensure every exterior surface on SailBot is water resistant and can endure various weather conditions.
- General Use Test - Confirm SailBot functions correctly as a unit
- User Test - Test that the controls are comfortable and easy to use with clearly displayed feedback.
- Installation Test - Ensure SailBot is portable and easy to install.
- Overrides Test - Confirm the emergency and discrete overrides work reliably.
The full test plan document is linked here.
A test rig, pictured below, was modeled after the back corner of a sonar sailboat where SailBot will be located. This assembly was built and is ready to be used for testing in the upcoming phases.
Risk and Problem Tracking
The risk assessment chart has been updated to reflect the current status of the project a the start of MSD ll. Previously, the budget was one of the most severe risks, but after gaining considerable funding from new sponsors, this risk is no longer a top concern. Moving forward into the build and test phase, technical risks relating to the durability and functioning of SailBot as a system will pose the most concern. Currently, no risk has manifested into a problem, but problems will be tracked and documented as testing begins and alterations are made to our design. The updated risk chart is linked here.
The BOM for this project was updated to reflect our most recent purchase order as well as the additional funding we received since the end of last phase. Most of the electrical components have been ordered and received. Most of the mechanical components were included in the most recent order so they should be expected to arrive within the next couple weeks. Metal stock, the gas spring (for the test rig) and material for the outer casing of SailBot will be the next big ticket items to be ordered. Currently, we are well within our budget and are on track to have money leftover after buying our fundamental components which provides us a considerable cushion if parts break or we need to change anything in our design.
Design Review Materials
Include links to:
Plans for next phase
Next is the Subsystem Level Build and Test phase. Plans and tasks for this phase include:
- Finalizing designs for the exterior casing and carrying case
- Submitting a purchase order for remaining mechanical parts and user controls
- Creating a subsystem functioning demo
- Building our first prototypes and begin testing subsystems
- Tracking problems and new risks that may be introduced
- Begin verification and keep organized documentation of testing and design changes
- Continuing to be in contact with the customer
Below are the three-week plans for each individual team member of the next phase:
Peer evaluations were done as a reflection of this phase and what we want to improve on for next phase. The document is linked here.