tlog -EE464 at UT-Austin
Technical Log of progess for ARL 464 Senior Design Project, Brushless Motor Controller for Underwater Vehicle , quicklinks - June Tlog ,
464 Senior Design
August 10, 2006
Final Report
August 9, 2006
Updates to Report
August 8, 2006
Final Presentation
August 7, 2006
Changes and Pics on SVN
August 3, 2006
Demo Day
August 1, 2006
Power Tests
July 31, 2006
Demo Poster
July 28, 2006
2nd Gen PCB changes
July 27, 2006
PCB contruction
July 26, 2006
PCB and Posters
July 25, 2006
FFT and Scooters
July 24, 2006
Prop Shrouds
July 22, 2006
SVN module Setup
July 21, 2006
ICD Programming
July 20, 2006
ROV and Large Tank
July 19, 2006
External Water Connectors
July 18, 2006
Hurst Motor and Presentation
July 17, 2006
July 14, 2006
PCB Ordering
July 13, 2006
Routing & Gerber
July 11, 2006
Layout 0.5 BLDC
July 10, 2006
Layout 0.4 BLDC
July 7, 2006
Schematic 0.4-0.4 Finished
July 6, 2006
Picking Power FETs
July 5, 2006
Patent Searches and IP
June 29, 2006
ICD and Schematic 0.2
June 28, 2006
Manual Control
June 27, 2006
Eagle Libraries
June 26, 2006
Mouser Order
june 22, 2006
PCB parts, datasheets
June 21, 2006
Design Review, EC Flat Motor
June 19, 2006
PICDEM LV MC
June 15,2006
Microcontroller Comparison
June 08,2006
Brushless Motor Selection
June 2, 2006
ESC Brushless Test
May 25, 2006
Proposal
Hi , my name's Andrew Lynch, I"m keeing this technical log to keep track of progress on my design of the brushless controller for 464 and ARL, with wiki docs and BLDC Pictures,
Final report (pdf) submitted, journal finished, Last day of oral presentations, journal uses this Tlog as the main structure with more graphs and pictures
Major components finished up on report, talked to Kyeon about possible revisions or guidance,
Final Oral Presentation (pdf) , Womack and Kyeon were present, demonstrated the concepts and physical hardware shots.
Wired DAQ - DataQ module for voltage, current, strain gauge logging on motor test rig,
Making updates to paper on SVN, the majority of the structure and log format is in place and the sections need to be filled in completly.
Help take apart Pittman motor for further testing
Demo Day involved an elaborate setup of the S12 brushless aircraft motor and hurst motor working with the custom BLDC . Look at the pictures posted from the presentation sessions. local pic
Power testing and software, smoked a current sensing resistor using dsPIC programming module. In retrospect, the current short is most likely due to a jumper incorrectly connected for sensorless PIC settings rather than dsPIC. However after frying the resistor, the dsPIC does not want to re-program back to original state.
Important changes made to 2ndGenBLDC , also added Demo Presentation Poster
Constructed the accessory components of the PCB, will upload to BLDC Pics (link...) and began comprehensive reference to part changes and potential revision for next generation in 2ndGenBLDC.
Finished up construction and testing on PCB, ready for programming and software communication. Learn the architecture and serial communication style of the RoboTeq controller to smoothly interface my brushless controller. Possibly look into interfacing to the Traks scooter and getting feedback on back-emf for different phases using current and voltage monitoring.
Printed and put together Poster Size and bill of materials (upload) . I setup serial communication code to interface with the microcontroller. Soldered parts onto PCB board which came in Tuesday, should be ready for testing soon.
Talked with L. T. and Riley about Acoustic Sensing with the HTI 900(link) and a SpectraGraph software using a sound card and converter cable to take the jack to BNC (from RadioShack). I'll try to put up a few screenshots of the FFT tests from 0-120Khz. Talked with Piper about the Dive-Xtras scooter, this motor seems capable of the torque (60lbs thrust) and speeds (800-1600 RPM) however, there are a few more graphs I need to collect. need to finalize Xtras Pitch to ARL
Help construct propellor shroud for Rev 1 motors, it looks like something from harley ! I also started sorting parts and organizing for construction. The board did not come in as expected but the UPS tracking number showed the board is in Austin. Helped prepare motor cabling for underwater usage.
Setup SVN instead of CVS for all code, documents and PCB files, using iarc1 as the server, for reference or access to the account, look under the andy464 module on IARC. reference the SVN tutorial for help in installing
Attempted to start up motor using ICD2 programming module, mixed success, the driver communicated properly but the assembly code for the 18F microcontroller was not loading onto the module this needs more development.
Went through testing procedures with Piper on large tank and studied different ROV models (see phantom ROV..link) and scooters see DiveX scooter (link..). There are transducer and amplifiers with scopes next to the large tank for testing noise ouptut of the motors and props submerged.
Worked on external water connections for disconnecting the motor while underwater. There will be a maximum of seven wires available for providing power and signal control lines to the motor control unit. The dsPIC testing still needs more work because the jumper settings don't give complete control with hall effect sensors. Need to test and probe hall effect sensors on Hurst motors to improve analog control of BLDC
Tested further stages on the BLDC control with dsPIC and new Hurst motor. The test was a success for simple potentiometer software therfore the hardware is working but the serial communication needs more work. I gave Progress Report presentation (link..) the audience feedback was really helpful but way over time, I am going to investigate the epoxy water sealant method for water flooding the PCB enclosure to avoid pressure issues and for single thruster testbeds
Scavenged through ARL part inventory for matching parts from the components on the BLDC project on mouser. The database could use updating because it is not as streamline as most online part distributors, After I merger of inventory list. I began the ordering process from Digikey and Mouser .
Ordered PCB from Advanced Circuits, using design checkers from freeDFM and BatchPCB, I was able to ensure my board would not be sent back for further design revisions. However there can still be defects so its best to get an electrical test at the PCB fabrication facility
I did have to add a top copper layer on the outline dimension layer because Advanced Circuits wanted a detailed outline, this delayed the PCB process by 1 day which translates the shipping date to 7/24/06
Finished Board layout, went through routing process. I used eagle's default Auto Router. When looking for making Gerber files, I referenced SparkFun Electronics for tips using CAM processing.
Today semi-finished the puzzle solving of laying out the board, the pictures look partly cluttered due to the surface mount devices (SMD) packages on the bottom and top, However within size constraints I should be able to get everything placed out judging by the proximity of the larger components. I fixed the D2PAK problem by putting the DPAK-TO252, STD45NF75 which was the correct size for N-channel Mosfet, look in 0.5 BLDC.brd , need to place two more orders from Mouser & Digikey,with generated Bill of Materials list from Schematic and checking part numbers with Mouser, all of the larger parts have been ordered and checked but SMD resistors and other passive components need to be ordered,
Started the layout process in Cadsoft's Eagle, noticed problem with package size of D2PAK for Power Mosfet 7815 (15V regulator) and the N-channel Mosfet (more on this later) . Starting Placing the larger parts for augury of wiring and nets, picture on the BLDCpics as 0.4 BLDC.brd file, Looked up reference sheet on capacitors
I am going with Tantalum Capacitors b/c small size and availibility
Completed the overall schematic 0.4 with a few loose ends such as temperature sensor, sonar connector and the usual ERC checker. Need to double check all datasheets and part numbers for verification, pictures will be on the BLDCpics page,
Made alot of progress on the board, analyzed different types of transistors N-channel for driving the Inductive Load (motor) , finally selected STD45NF75T4 , Also compared different oscillators and ceramic resonators, panasonic has a 5Mhz available form digikey
4th of July was great, the shuttle launched, I wrote most of the IP
report, I uploaded a large majority of my patent searches,
To avoid really long pages, I archived June 2006 Tlog (Tech Log)
Added BLDC schematic to "rc_drive" module on the repository, putting together test video of BLDC control with scematic screenshots
Learned about IDC and RJ-12 connectors, Great Webinars
Put together PICDEM, to control, tried manual control but the motor would not start moving, checked user's guide for troubleshooting, going through serial API as well, put together BLDC wikiTrac documentation
Found great CadSoft's Eagle Libraries , these had the dsPICF30F3010 and Microcontroller pinouts for 18F2431 (used 18F2455), Also found useful library hints from Scott Torborg, I'll try to post the layout and schematic screenshots in the upcoming "media" section
Mouser Order arrived, went through and sized up parts for connectors and dimension for the board layout. Still need to find a few basic parts, such as SMD resistors, 5Mhz Oscillator, and SMD switchs/capacitors.
Put together an order on mouser for the Molex connector and a variety of parts for the upcoming PCB design. Mouser has a really good cross reference system, however I could not locate a 5 Mhz oscillator for banananas ! I'm going to dig through a few datasheets looking for something useful
The maxon EC flat motor has come in, but I don't have the proper molex connector to wire the motor to the PICDEM board. Put out the final revision in the Design Review,
Received the PICDEM LV MC kit, unfortunately I was not able to hook a surplus NIDEC motor I borrowed from Professor Valvano. I send an email to NIDEC about finding more specifications on the motor wiring, sadly the details of that specific motor are only avaiilable to the company for which the motor was made,
Finalized talks about microcontroller and sensors for the BLDC. Microchip's availability and low cost pervailed over Freescale and Atmel. However all three of the companies had a very solid BLDC evaluation kit, the documentation and lead-time was the biggest factor in my decision.
Located a few great candidates for a brushless motor, Kollmorgen and Maxon. Found a few secondary selections from Pittman, Faulhaber and Xnergy but the lead time was somewhat long, for complete details of my technical adventures, look through the upcoming design review ,
Put together an ESC for a brushless motor for a small helicopter, the motor worked amazingly well except for low speeds in which the back EMF sensing failed due to lack of magnetic field,
Put together finished touches on proposal review for initial design plans Started lining up documentation and reading guidelines for project and other potential projects, found great Senior Design reference,
email lyncas A T g m a i l for more info