Overview of Status of Analysis, Design, Fabrication, Tests, etc.
Built the single-source version of the active low-pass filter (cutoff frequency of ~10 Hz, requires only one power source)
Tested the single-source filter + sensor and determined it can measure 10 g - 10 kg (~0.1-100N) with a resolution of ~2 grams at both high and low end range
Designed the ergonomics of device (preliminary CAD) and planning to print/cut on Friday 5/12
Accomplishments from Previous Week
Learned from collaborator that he wants:
A 0.1-100 N range which means don't need to preload the sensor, but do need a larger dynamic range than expected
Only one setting as opposed to several ones to slowly make up the 0.1-100 N
Goals for Next Week (list names after each item). Use specific and measurable objectives.
Build prototype of ergonomics with printed/laser cut parts (Team)
Find weights to calibrate the full range of the sensor (Team)
Set-up one sensor with coax cable and compare performance to twisted pair (Team)
Arrange to check out data acquisition system (Team)
Sponsor Comments from Last Meeting and Actions Taken to Address these Comments (indicate date of comments and if via email or in person)
Asked to contact Sam (collaborator) for more details. We contacted him via email and got a response back that clarified dynamic range and use case
Recommended to lower the cutoff frequency of the filter to 10 Hz because of sampling rate of 40 Hz. We modified the filter to have a 10 Hz cutoff frequency.
Instructor Comments from Last Meeting and Actions Taken to Address these Comments (indicate date of comments and if via email or in person)
Suggested we get started on the ergonomic design ASAP and make sure to design considering that it would be held by a person. We've completed preliminary designs and made sure to round all edges.
Comments from Other Students in the Class (indicate date of comments and if via email or in person)
None
Risks and Areas of Concern
Linearity of sensor over the full range (so far we've only gone up to 1.5 kg)
Resources or Information Required but not Available
None
Schedule
Week 6: print/cut and assemble first ergonomic prototype
Week 7: calibrate full range of sensor, try out data acquisition system
Week 8: test device in the MRI (compare coax to twisted pair - if not week 7)
Budget (list amount spent and amount remaining)
Spent $134.66 of $600 part budget
$465.34 remaining of part budget
$600 remaining of shop budget
Progress on Report and Webpage
Report first draft was uploaded last week and will revise based on instructor feedback (when received)
Webpage being kept up to date