Overview of Status of Analysis, Design, Fabrication, Tests, etc.
We were able to cut 3mm PVDF strips with the automated cutter. We will encase the sensor with a layer of Kapton tape for protection. The connection point will be encased with insulative epoxy. The finalized sensor layout consisting of 16 sensors (15 for location and 1 for force) will be adhered to the acrylic face and handed off for DAQ testing.
A closer look at the single ended piezoelectric sensor input versus the differential sensor input indicated that the sensors produced less voltage when applied to a single ended channel, so amplification of the signal is now necessary.
Signal conditioning circuitry finalized, utilizing an serial interface programmable gain amplifier to allow for incremental adjustment of gain.
Final surface mount electronic components for data acquisition selected and ordered, memory requirements finalized.
No pattern has been founded on how to extrapolate location or force from the sensor's data.
Accomplishments from Previous Week
Automated Sensor cutout complete (Reuben)
3D printed Test stand and assembly (Reuben)
Finished sensor connection epoxy encasement for testing (Kaitlynn)
Adhered sensors to acrylic for testing (Kaitlynn)
4 Sensor location testing and data collection (Reuben and Kaitlynn)
Sensor encasement resolution--Kapton (Reuben and Kaitlynn)
Hand drawn data acquisition circuit layout developed (Chris)
Final electronic components chosen with integration and Arduino IDE compatibility in mind for data acquisition system (Chris)
Trigger accelerometer selected and ordered (Chris)
Finished analyzing all the data of experiment 1 on 04-14 (Michelle)
Started running some data transmission speed tests (Michelle)
Goals for Next Week (list names after each item). Use specific and measurable objectives.
Finalize golf face CAD (Reuben)
Finalize sensor layout (Reuben)
Fabricate 16 PVDF sensors for DAQ testing and final layout (Kaitlynn)
Finalize sensor encasement strategy (Kaitlynn)
Adhere final sensor layout to acrylic and hand off for DAQ testing (Kaitlynn)
Create digital circuit layout and printed circuit board layout for data acquisition system in Autodesk Eagle (Chris)
Continue developing code to: trigger sampling, switch multiplexer, program gain, and write to external memory (Chris)
Assemble prototype data acquisition circuit with new components and more than four total channels (Chris)
Finish up data transmission speed testing (Michelle)
Continue with refining MATLAB skeleton code (Michelle)
Sponsor Comments from Last Meeting and Actions Taken to Address these Comments (indicate date of comments and if via email or in person)
Dr. Loh recommends Kapton tape over electrical tape to protect the sensor. Electrical tape is thicker, dampens impact, and can add inconsistency to results. (4/15 via Zoom)
The "lighting streaks" on the PVDF are normal. They indicate where the highest current flows in that region. It can enhance or reduce the performance. (4/15 via Zoom)
Silver paste can be used as a band-aid for scratches on the PVDF to rebuild the connection, but try to make the layer as thin as possible. There is a small concern with the organic solvents eating through the PVDF and causing a short, so just use care with application. (4/15 via Zoom)
The inconsistencies in sensor readings are OKAY and expected. Dr. Loh recommends we establish a baseline and calibrate based on that. There is no way to get two sensors exactly the same given the material imperfection in commercial products among other things. The automated cutter will help with geometric similarity and reduce errors. (4/15 via Zoom)
Ensure the sampling rate remains high for 16 sensors. (4/15 via Zoom)
Instructor Comments from Last Meeting and Actions Taken to Address these Comments (indicate date of comments and if via email or in person)
Follow up on emails that do not receive a response within one day. (4/13 via Zoom)
Email Ian Richardson about the index number. (4/13 via Zoom)
Are we looking at both positive and negative voltages? We're looking at just positive voltage to get the maximum voltage at impact since we're not concerned with the vibration/oscillation after impact. (4/13 via Zoom)
How are we making sure we get 5V? We're using a voltage divider to attenuate the signal based on voltage readings. We can adjust the analog to digital converter based on resolution needs. (4/13 via Zoom)
Are we triggering the sampling or storing/analyzing later? We intend to use an accelerometer to trigger the swing and begin sampling. We could use a delay if we know how long after the swing is initiated that impact will occur. A 3 axis accelerometer could help with angle detection to be incorporated. (4/13 via Zoom)
How are the sensors degrading? We hypothesize they degrade primarily due to the flakiness of the silver paste over the connection point which is why we're encasing in epoxy. The handling and care of the sensors also play a role, so we're covering the sensor with Kapton tape to protect it from damages. (4/13 via Zoom)
Would a silver epoxy be better? We need to avoid it touching the sides of the sensor (difficult with 3mm sensors), so we have more control with the silver paste and using an insulative epoxy. (4/13 via Zoom)
Get approval for the impulse hammer, and go through the MAE Department. (4/13 via Zoom)
Comments from Other Students in the Class (indicate date of comments and if via email or in person)
N/A
Risks and Areas of Concern
N/A
Resources or Information Required but not Available
N/A
Schedule
Fabricate 16 sensors for final design
Budget (list amount spent and amount remaining)
Amount Spent: $1,421.43
Amount Remaining: $1,478.57
Progress on Report and Webpage
Applicable standards due midnight Friday