P09204: Second Generation Design Team Members: Jason Jack Nandini Vemuri Jeff Howe John Corleto Emily Phillips Ryan Schmitt
Build a control system to command interchangeable motor modules Control system must be: Open-Source, Open-Architecture Modular Scalable, Programmable Control system must be controllable by payload or Windows/Linux PC System must be smaller than previous units
Decade size reduction Microcontroller within control system assembly Fully documented, seamless handoff Reusable GUI Expandable system design Minimum 1-hour battery life, separate supplies
Motors must be efficient, easily controlled, cheap, widely available Battery must be smaller, lighter Power Distribution needs to be more robust than previous teams implementation Software Implementation must exercise all hardware capabilities Wireless datalink must have minimum range of 100 ft.
Selection Criteria Segment Weight A B C Freescale BDMicro Arduino Nano RatingNotesWtdRatingNotesWtdRatingNotesWtd Speed5%3 16MHz MHz MHz 0.15 Memory20%2 2KB KB KB 0.20 Open Source15%1 Closed Source avr-gcc Open Source 0.45 IDE Flexibility15%1 Code Warrior Use Anything Use Anything 0.45 Small Size20%1 Not Small Small NANO! 0.60 Existing Code Base10%3 Expansive Libraries Open Source Fully Modular Driver Base Arduino Libraries 0.20 Expandable Memory10%3 8-bit Mem Interface X-RAM Interface Nothing 0.10 Experience5%3 CE Experience Easy Learning Curve None have used Arduino Architecture 0.05 Total Score Rank 1 3 2
DC/ServoDC/DCStepper/StepperDC/Stepper Cost4213 External Circuitry4123 Design Complexity Software2341 Hardware4123 Efficiency3412 Research Required1243 Scalability3142 Stall Torque Drive1342 Steer4434 Total: Rank:4132 BestWorst Cell Ranks:41
Microcontroller did not have the capacity to generate all necessary control signals Stepper motor drivers had non-deterministic behavior, required excessive control signals Crossbow Wireless had confusing, custom programming; too complex for design Errors in PCB design post-fabrication mandated changes late in development cycle
Power Distribution – Logic and Motor Motors – DC and Servo Microcontroller – BDMicro Atmel ATmega128 GUI – Continuous and Incremental Control Operational Software – Command Protocol PID controller – Arduino Nano Wireless – IOGear Bluetooth Serial Adapter
Single Unit: $ $ per unit Lot of 10: $ $ per unit Lot of 100: $ $ per unit Lot of 1000: $ $ per unit The per unit price drops dramatically between a single unit cost and a lot of 10, however due to COTS fixed costs there is not much benefit for purchasing in larger lots than this
Merge power supplies Redesign power supplies to use isolated switching supplies (isolate motor spikes from logic) Merge microcontrollers Merge DC Drivers Further research into PCB manufacturing, reduce costs Reduce cabling, merge headers
Light seeking plant carrier “Birds-eye-view” robotic Pacman game Robot “battle” competition Robot dance competition Autonomous, mobile paintball sentry robot Software engineering project, further GUI development Electrical engineering project, improve electrical systems design