nuclear a2d design
DESCRIPTION
Nuclear A2D Design. Critical Design Review Group #09 Kristen Berman Joseph Nichols Cassandra Todd Michael Zellars. Project Motivation. Our group wanted a mentor/project sponsorship - PowerPoint PPT PresentationTRANSCRIPT
Analog A2D Design
Nuclear A2D DesignCritical Design ReviewGroup #09Kristen BermanJoseph NicholsCassandra ToddMichael ZellarsK1Project MotivationOur group wanted a mentor/project sponsorshipACTIVE Lab (Applied Cognition and Training in Immersive Virtual Environments) has a partnership with the NRC (Nuclear Regulatory Committee) Nuclear power plants primarily contain outdated technologyThe ACTIVE group will use our device to test a transition from analog to digital control technology
K2Goals and ObjectivesCreate a working hard and soft panel that will support the ACTIVE group in their testingHard panel will consist of an extensive PCB design, multiple types of analog controls and needs to establish and maintain connectivity to the soft panelSoft panel will be an accurate representation of the hard panel and needs to both accept inputs and send outputs to the hard panelIn addition needs to establish and maintain connectivity with both the hard panel and the power plant simulatorWe want to try to keep the hard panel to a reasonable sizeK3Specifications & RequirementsHard Panel will consist of about 100 components (switches, push buttons, gauges and LED sectors)Analog controls (Push buttons and switches) will need to be able to indicate current statusPower protection circuits will keep the panel temperature low and noise level maintainedEach device will be labeled with a 7 character alphanumeric stringBoth panels need to be user friendly to appeal to the novice user but still remain customizable to adapt to the different testing environments needed by the ACTIVE groupAll components will reside in a LANSoft panel will use UDP transmissions to communicate with the Power Plant Simulator
K4System Block Diagram
J5MicrocontrollersMaster/Slave ConfigurationOur Master MCU will control two Slave MCUsMaster MCU ATmega325 (used for overall control as well as push buttons & rotary switches)Slave #1 MCU ATmega8 (used for control of gauge subsystem)Slave #2 MCU ATmega32 (used for control of LED subsystem)Serial Peripheral Interface was chosen to execute this configurationMaster will utilize SPI to transmit/receive data from the 2 slaves
J6MicrocontrollersAVR ProgrammingAVR Processors use RISC architecture computers we will be using will run either x64 or x86 so a cross compiler is necessaryTo implement this we will use Atmel Studio 6 for Windows PCs as well as the command line program AVRDUDEWe will also use an Arduino Uno to program our AVR microcontrollersThis supports in-system programming while designing our circuitAlso, Arduino offers ArduinoISP firmware which provides us with tutorials and code to burn a bootloader onto an AVRJ7MicrocontrollersCommunicationIn order to establish a connection between the Master MCU and the soft panel we will use the RS232 serial data standard
Housing UnitWill require Acrylic and Sheet MetalNeed to make sure to have smooth edges (no hazards)Acrylic will be used for casings around the gauges and the LED boxMetal will be used for the overall housing unitPositioningLight box sector needs to stretch across the topAll other devices will be grouped together
Analog Controls
K10Analog Controls
26 Push Buttons have been purchased in both Red and Green colors and 25 Rotary Switches have been purchasedThese items will be connected directly to the Master MCU and main PCB boardDue to their purely analog nature, they require status LEDs to indicate connectivity to the Soft PanelK11Analog Controls
Gauge Design
M12Detailed Gauge Design
3D Print JobCustom needle design via SolidWorks
24 needles to be printed
Material cost at $0.35 / cm3 $5.09
Analog Controls
LED Box Design
C15Hardware Block Diagram
C16Power CircuitDesign RequirementsSolutionPlug and play Take power directly from wall outletOperating Voltages 3-5VDCAC-DC buck boost converter Isolated sourceChopper circuit and feedback controller
C17Printed Circuit Board DesignEach subsystem will be placed onto its own PCB3 boards in total will be designedMaster MCU, power circuit, rotary switches and push buttonsGauges subsystemLED subsystemSeparating into subsystems cuts down on issues to potentially be found and will hopefully make testing each subsystem easierAll PCB work will be designed in EAGLE design software and sent to a manufacturer for assembly18Software Block Diagram
M19Soft PanelThe GUILED sectorSwitchesGaugesPush Buttons
LED Sector
Three states:OnOffFlashingSwitches
Lever is moved by clicking and dragging
Status LED indicates on or off
Gauges
PrecisionSmooth movementPointer acceleration and deceleration will be implemented in the futurePower Plant SimulatorJava-based application running on a separate PCHandles user input Button pushingSwitchingReturns output to control panels Change in gauge statesChange in LED states
UDP Multicasting
Power Plant Simulator sends each output command with a UDP multicastThis means that every control panel within the network receives the same transmissionMulticasting is used to keep network traffic minimal and ensure the system is in syncDesign Decisions4 Layer PCBMost important decision for a PCB is the number of layersThe 2 PCBs that support the gauges and LED subsystems will each be double-sidedThe 3rd PCB will have a more complex design and will therefore require more layers2 signal layers, a ground layer and a power layer
Design DecisionsMicrocontrollersOur hardware design is centered on the ATMega series of microcontrollersThe table outlines the 3 microcontrollers that were selected and key characteristics
Design DecisionsPower circuitIsolated Flyback Buck Boost ConverterIndustry StandardCan Perform both buck and boost operationsMore efficient designBetter at conserving energyCapable of storing energy during on state of system
Current Successes & DifficultiesWorking Gauge Prototype90% of parts are orderedTentative Soft Panel LayoutStaying under budget
PCB Accuracy Fear of a shortGeneration of excessive heat during the DC-DC transformationMain regulated voltage wont be 3.3V @350mAPotentially might need an LED driver to provide a constant current source
Project BudgetItemQuantityCostPurchased?Push Buttons26$39 Switches25$172.50 Stepper Motors25$70 Shift Registers15$7.20 Light Box LEDs25$18.50 Indicator LEDs26QuotingXMCUs9Free PCB4 Layers$200XHousing Unit Metal & AcrylicQuoting$70XElectrical ComponentsVarious$80 Cords3$45 Electrical Grounding Equipment3$20 Total Funding Allotted: $991.25Total Amount Spent: $493.32Amount Projected Left to Spend: $335Amount Estimated to Save: $162.93Work RolesTeam MemberWork DistributionKristenSystem Communication & Administrative ContentJoePrimary PCB Design & MCU ConfigurationCassiePower Circuit & LED Circuit DesignMikePrimary Software Engineer & Gauge DesignCurrent ProgressImmediate PlansAiming to have PCB orders in by January 31stWill finish up remaining part orders by the 31st as wellFebruary will transition into a coding focus MCU & Soft Panel
Special Thanks
Questions?Rectifier and Filter
Chopper
DC-DC Transformer
Output Rectifier and Filter
Feedback Controller
AC In
DC Out
DC
DC Out