Overview of Status of Analysis, Design, Fabrication, Tests, etc.
In the process of establishing pump control (Teng)
Considering change control method from RS-485 back to analog voltage control
Started machine shop (Shen)
Simulating velocity profiles and determining which size/configuration of diffuser will need to be 3D printed (Damien)
Redesigning chamber and apparatus setup to accommodate lighting source now provided by Ben at SIO
Redesign the chamber and steup stage to meet SIO requirement for lab setup (Kimi)
Accomplishments from Previous Week
Set up RS485 communication on Beaglebone and enabled the transmission mode (Teng)
Used Comsol to simulate three different chamber/diffuser configurations (Damien)
Completed two pieces from machine shop(Yuling and Teng)
Redesign the chamber to use clear front and back piece and machined middle piece (Kimi)
Receive and test the lighting from SIO
Receive and test lens from SIO
Test the camera FOV: 13mm*10mm
Goals for Next Week (list names after each item). Use specific and measurable objectives.
Achieve open-loop control on the pump using RS485 protocol/analog voltage control (Teng)
Flow simulation on finer resolution diffuser design for smaller chamber size design. Need computer with more RAM to run Comsol sim (Damien)
Finalize the design and finish machining and 3D printing all necessary parts (Kimi)
Have assembly materials delivered and machine shop pieces completed. Possibly finish the fabrication by the end of next week (Yuling)
Sponsor Comments from Last Meeting and Actions Taken to Address these Comments (indicate date of comments and if via email or in person)
16 April 2015- Meeting at SIO with Dr. Jaffe and Jessica
Sponsor aksed about pump control progress (Teng)
Was able to find information online for configuring RS485 on BBB (Teng)
Emailed the pump company US branch for data sheet, got forwarded to company in China and haven't heard back from them yet (Teng)
4/21 update: heard back from the company and got the data sheet (Teng)
Back-lighting is required (Damien)
For camera focusing, the chamber wall thickness must be < 2mm and the horizontal depth of the chamber must be <20 mm (Damien)
Use objects that sink < 1mm/s (i.e. not the fish eggs from risk reduction), may need to create our own (Damien)
Ask to talk with engineer (Ben) in Dr. Jaffe's lab to receive a previous setup stage for design guidance (Kimi)
Instructor Comments from Last Meeting and Actions Taken to Address these Comments (indicate date of comments and if via email or in person)
15 April 2015
Determine sinking speed of object
Check BBB spec sheet to determine response time
Ensure motor response is fast enough for controlling sinking objects
Build control system model
anodize aluminum
3D print honeycomb diffuser
Use plastic fittings
Need additional screws for attaching front (and back) plastic panels
Objects that rise
After talking to the sponsor last week, this is no longer a requirement of our design.
(Damien)
Need to find an object with same sink speed around (1mm/s) (Kimi)
Change density of parts
Change density of water
Need to figure out what is the impact of society
Check motor response time
Have searched the official website but no spec sheet for pump motor is provided. Tested by manually add or drop the rmp, the response time is small enough that hard to tell (less than 0.1s) (Yuling)
Comments from Other Students in the Class (indicate date of comments and if via email or in person)
Risks and Areas of Concern
Pump control (Teng)
The RS485 serial cape uses the whole break out board for RS485/RS232 communication and so leaves no pin for analog input (Teng)
The data sheet for the BT100-2J pump RS485 protocol is not available online and relevant information is hard to find (Teng)
An alternative method is to use analog voltage control but the pump producer said the pump had a low resolution for analog input (Teng)
Velocity gradient < 5% of width > 5mm (Damien)
Flow simulation using software
Flow simulation using Comsol runs out of memory (Damien)
The solidworks flow simulation presents untrustful results (Yuling)
Chamber (Kimi)
Whether chamber shape is machinable
Whether oring will prevent leaking
Whether clear front and back acrylic is good enough for image acquisition and light illumination.
Resources or Information Required but not Available
Computer with lots of RAM (>12 GB) to run Comsol simulation - I am looking into using a server-client approach (Damien)
Schedule
Describe upcoming milestone
Update Gantt chart.
Budget (list amount spent and amount remaining)
Total: $3000 (KImi)
Spent:
$2.95 (Fish eggs)
$346.91 (Mightex Camera)
$335.4 (Pump)
$43 (RS485 Cape)
Remain: $2271.41
Progress on Report and Webpage
Added impact on society to Report Draft / edited previous version