156B Week 3

Overview of Status of Analysis, Design, Fabrication, Tests, etc.

• • Laser Triangulation Range Finder

    • Having difficulty identifying laser dot

    • Laser dot does not show up well in bright sunlight

    • Looking into alternatives to laser rangefinder

  • Relative Positioning via Feature Tracking

    • Following OpenCV tutorials

  • Custom Waterproof Enclosure

    • Housing meets design factor of safety in flat plate deflection calculations for 10m depth.

    • Initial component layouts have been modeled.

    • risk reduction on the custom housing bonding approach 04/20.

  • Electronics

    • Selected Raspberry Pi 3 as processor

    • Most items have been purchased

    • Wire routing and connectors need to be worked out

• • Thrusters

    • Motors and propellers have been purchased

  • Emergency Buoy

    • Circuitry finalized, procuring necessary components.

  • Buoyancy Control

    • Linear actuator is identified, and design around this object has begun

Accomplishments from Previous Week

• • Tested laser tracking algorithms (Daniel)

  • Tested laser visibility underwater (Daniel, Justin, Stuart)

  • Decided on processor (Daniel)

  • Scheduled pressurized housing leak test with Tom (Jacob)

  • Started housing leak test prototype (Jacob)

  • Can we get a hold of Blue Robotics' new echo sounder before it is officially released? Nope.

  • Met with Devin and Paul to finalize failsafe method and circuitry. Ordered some of the necessary components. (Grant)

Goals for Next Week (list names after each item). Use specific and measurable objectives.

• • Perform pressurized housing leak test (Group)

  • Finish preliminary design CAD of housing (Jacob)

  • Finish CAD of ABC and begin prototype

  • Prototype and begin testing failsafe method (Grant)

Sponsor Comments from Last Meeting and Actions Taken to Address these Comments (indicate date of comments and if via email or in person)

• • Don't spend too much time on range-finding if it proves to be too difficult.

Instructor Comments from Last Meeting and Actions Taken to Address these Comments  (indicate date of comments and if via email or in person)

• • Refraction might cause problems with finding distance to bottom with lasers (Young, at presentation, 2017/4/11)

  • The housing is going to leak. Consider torque standards in designing custom housing. (Gillette, 2017/04/11)

    • Perform pressurized leak test on custom housing prototype.

Comments from Other Students in the Class (indicate date of comments and if via email or in person)

Risks and Areas of Concern

• • Rangefinding

Resources or Information Required but not Available

• • Will infrared laser rangefinders work underwater at ranges of 0.5~3 meters?

  • Can an air ultrasonic transducer be used underwater?

Schedule

• • Get drivers for sensors/controllers together and talking on the ras pi.

  • Update Gantt chart.

Budget (list amount spent and amount remaining)

• https://docs.google.com/spreadsheets/d/1ClLdrAeYt9Xm-TOISy7Upd8Pb7oDbCv_VEf1yW20Bqg/edit#gid=0

Progress on Report and Webpage