Preliminary Design ReviewNASA Wireless Smart Plug (NWSP)

Experimental Control Logic Labs

October 29th, 2012

2PDR Agenda1. Update of documents developed and baselined since SDR

2. Matured Concept of Operations

3. Updates to Engineering Specialty Plans

4.Top-level Requirements and Flowdown to the next level of requirements since SDR

5. Review Design-to Specifications (hardware and software) and Drawings, Verification and Validation plans, and Interface documents at lower levels; CAD model for all physical components of the system

6.Trade Studies that have been preformed since SDR and their results

7.Engineering Development Tests and Results

8.Select a baseline design solution

9.Review and discuss internal and external interface design solutions (and any interface control documents needed). This includes interface information provided by NASA since SDR

10.Review system operations

11.Design Analyses and Results

12.Risk Management Plan

13.Cost and Schedule data

3Update of Documents Developed and Baselined System Architecture

Lower level details provided to depict the use of NASA requested components based on the X-Hab Solicitation

Functional Block Diagram Fuses in primary 28V-DC and 120V-DC load lines have been

removed after NASA requirement’s were clarified that the NWSP is not to operate as a safety device

Nivis ISA100.11a Release Version Habitat Demonstration Unit (HDU) gateway currently running

release 2.6.39 HDU VN210 firmware currently running version 4.3.14

(Upg_VN210_FullAPI_SpeedupSPI_ExtWakeup_v04_03_14)

4Matured System Architecture

Nivis VersaRouter 900 Master Control UnitWindows OSLabVIEW GUI

1 sample/secondISA100.11aIEEE 802.15.4

NASA Wireless Smart Plug

DSHNetwork

End Device

x5

120V-DCor

28V-DC

120V-DCand/or

28V-DC

Nivis VersaNode 210

5Matured Concept of Operations

• NASA Wireless Smart Plug (NWSP) is a proof-of-concept prototype

• Installed in the Deep Space Habitat (DSH) mock-up for testing and evaluation purposes only (not space qualified)

• Used to monitor and control power usage of DSH and its installed equipment

• Monitor current draw from end device, and define actions based on measurement (i.e. wireless communication, manual disconnect, load shedding).

Updates to Engineering Specialty PlansNivis Equipment that was supplied by NASA on

October 26th: PCB with MSP430 and Nivis 210 Radio

Nivis VersaRouter 900

Nivis equipment to be supplied by NASA: Embedded software for MSP430 and Nivis 210 Radio

6

7Top-Level RequirementsPower Control

Support for 120V/28V DC Near real-time monitoring Fail safe Windows based master control unit

Communications Wireless configuration, control, monitoring and reporting Data rate: 1 sample/second Use a Nivis VN210 radio Support a Nivis VR900 router Standards: SPI, ISA 100.11a

Form Factor & Fit Small form factor Cannon-type connector Integration with DSH Deliver five NWSP units for evaluation

Requirements Flow Down 1/3

Power Control

Voltages Monitor Fail Safe Threshold GUI

28VDC

120VDC

0 to 5A

3% Full Scale

0 to 5A

0.1A Inc.

Alert

Standalone Executable

Windows OS

8

Requirements Flow Down 2/3

Communications

Data Rate Equipment Protocol

1 sample/s

Alert Within 3s

Nivis VN210

Nivis VR900

ISA100.11a IEEE 802.15.4

SPI

9

Requirements Flow Down 3/3

Form Factor & Fit

Size Integration

3” x 3” x 3”

Cannon-type Connector

5 NWSP

DSH Install

10

11Design-to Specifications Voltage:

Input: 28VDC and/or 120VDC Output: 28VDC or 120VDC

Monitor Current: 5A, ± 3% of full scale Data Collection: 1 sample/second User Interface: Standalone application on Windows-based

MCU. Communication:

Integrate into DSH wireless mesh with Nivis VR 900 gateway Radio: Nivis VN 210 Standard: ISA100.11a

Size: 3” x 3” x 3” target. Power Consumption: Minimal Deliverables: 5 NWSP units, installed on DSH mockup.

12CAD Model for Physical Components

Trade Studies and Results:Current Sensor

13

Device Type Pros Cons Cost

ACS714 Hall Effect Small package Negligible power

dissipation Single 5V supply 40A Range

• Requires offset, gain, and low pass filter

$3.89

CMS2015 MagnetoResistiveCurrent Sensor

Electrical Isolation 15A Range Small package

Bipolar 15V supply Relatively expensive

$35.20

VCS1625 High Precision Shunt Resistor Very small package

Non inductive, non capacitive

No ringing

Power Dissipation Heat

$20

Trade Studies and Results:120VDC to 28VDC Conversion

14

Device Type Pros Cons Cost

667-ERA-8AHD300V

Voltage Divider • Inexpensive• Small package

• Power dissipation• Heat• Fluctuations in output

$2.53

MC33363B High Voltage Switching Regulator

• Small Package• Inexpensive• Negligible heat

• Noisy• Large current draw of >1A• Requires 40V supply

$1.60

TL783 High Voltage Linear Regulator

• Adjustable Vout • Limited output current• Significant waste heat

$2.55

Trade Studies and Results:Voltage Regulator

15

Device Type Pros Cons Cost

LM317L Linear Voltage Regulator

• Low output noise• Programmable output• Cheap

Inefficient Heat

$.49

ADP111 Switching Regulator Efficient

Low Heat

Relatively Expensive $2.44

N/A? Hybrid Regulator Efficient Low Heat Low Noise

Larger space required Relatively Expensive

N/A?

Trade Studies and Results:Voltage Switch

16

Device Type Pros Cons Cost

Micropac 53238

OptocoupledPower Mosfet

• Small package• Operates up to 125V• Can handle 5A

continuous• Radiation tolerant• Can be controlled with

pin from MSP430

• Heat • Power dissipation• Long lead time

Unknown

AV3712613 Relay • Can be controlled with pin from MSP430

• Inexpensive

• Mechanical• Power dissipation

$1.61

SH20DC20-16 High Power DC Solid-State Relay

• Can handle up to 20A continuous

• Low control voltage of 3.5V

• Can be controlled with pin from MSP430

• Large $23.56

Trade Studies and Results:Connector

17

Device Manufacturer Pros Cons Cost

HBL2513 Hubbell • Operates up to 208V• Can handle 20A

continuous• Fits NASA requirement• Available locally• Locking

• Not quarter turn $73.44

Veam GRH Cannon • Operates up to 250V• Can handle 15A

continuous• Quarter turn locking• High shock and vibration

resistance• Fits NASA requirement

• Not available locally Unknown

PDS-222-4 Amphenol • Operates up to 200V• Can handle 10A

continuous• Designed for space

operation• Quarter turn locking

• No 5 pin layout available• Not available locally

Unknown

18Trade Studies and Results:Microcontroller

Manufacturer Microcontroller Pros Cons Price per Unit

Texas Instruments

MSP430F5438A • Large memory size of 256KB• Low operating voltage (1.8 ~ 3.6V)

• High cost $11.73

Microchip PIC24FJ128GA110 • Cost • Less precise A/D convertor of 10 bits

$4.76

Freescale MC56F8257VLH • Fast processing speed of 60MHz

• No UART communication• Higher supply voltage necessary

$7.15

19Engineering Development Tests: Analog-to-Digital Converter 12-bit ADC Internal to MSP430F5438A

Internal Reference (2.5V) Sample-and-Hold 14 External Channels

Offset

Gain

LPF

20Baseline Design Solution:Functional Block Diagram Overview

21Functional Block Diagram:Voltage Step Down and Regulation

22Functional Block Diagram:Current Sense and Disconnect

23Functional Block Diagram:Nivis VN210 SPI Interfacing

24Internal and External Interface Design Solutions: SPI

Serial Peripheral Interface Bus (SPI) Synchronous serial data link standard Full duplex mode Master/Slave mode where the master device initiates the data frame Multiple slave devices are allowed with individual slave select (chip

select) lines The SPI bus specifies four logic signals:

SCLK: serial clock (output from master) MOSI: master output, slave input (output from master) MISO: master input, slave output (output from slave) SS: slave select (active low, output from master)

25Internal and External Interface Design Solutions: SPI

Advantages•Full duplex communication•Complete protocol flexibility for the bits transferred •Typically lower power requirements due to less circuitry (including pull up resistors)•Slaves use the master's clock, and don't need precision oscillators•Slaves don't need a unique address — unlike I²C or GPIB or SCSI•Transceivers are not needed•Uses only four pins on IC packages, and wires in board layouts or connectors; fewer than parallel

interfaces•At most one unique bus signal per device (chip select); all others are shared•Not limited to any maximum clock speed, enabling potentially high throughput

Disadvantages•No in-band addressing; out-of-band chip select signals are required on shared buses•No hardware flow control by the•No hardware slave acknowledgment•Supports only one master device•No error-checking protocol is defined•Generally prone to noise spikes causing faulty communication•Only handles short distances compared to RS-232, RS-485, or CAN-bus•SPI does not support hot plugging (dynamically adding nodes).

26System Operations:Initialization

Connect NWSP male input

receptacle to DSH

Run LabVIEW GUI executable

Request parameters from

NWSP configuration

Set end device parameters

Current Threshold

Priority

Test connection between NWSP

and GUI

Established Connection?

Reset physical connection and

executable

No

Parameters Set?

Yes

NoConnect end

device to NWSP female output

receptacle

Yes (A)

Mode

27System Operations:Standard Operation

(A) Close switch of primary supply line to allow end device

operation

NWSP measures actual current and

voltage(s)

Actual Exceed

Threshold?

Compare actual current against

configured threshold current

Send all measured values to GUI

Actual Current of Primary

Voltage Point 1

through 7

Mode?

Send all measured values to GUI

Yes

NoSend all measured

values to GUIPrompt user to

disconnect

Manual

Automatic

DisconnectPrimary supply line from end device

Notify user of disconnect

User Request

Disconnect?

No

Yes (B)

(E or F)

(D)

(C)

28System Operations:Disconnect and Reset

(B)

DisconnectPrimary supply line from end device

Notify user of disconnect

Prompt user to reconnect

User Reconnect?

Wait for user to manually reconnect

No

Reconnect Device

Yes

(F)

(F)

(D)

User Disconnect?

(C)

Yes No(E)

GUI Updates - Detailed View

GUI Updates

Master Control Software Logic

Master Control Software Logic

33Design Analyses:Sampling and Decision Algorithm Process of averaging multiple samples for noise

compensation through statistical analysis: Defining the population of concern Specifying a sampling frame, a set of items or events possible to

measure Specifying a sampling method for selecting items or events from

the frame Determining the sample size Implementing the sampling plan Sampling and data collecting

Factors Nature and quality of the frame Availability of auxiliary information about units on the frame Accuracy requirements, and the need to measure accuracy Whether detailed analysis of the sample is expected Cost/operational concerns

34Design Analyses:Power Budget

Device Max Current DrawVersaNode210 60 mAMSP430F5438 312 uAACS714 Current Sensor IC 13 mASH20DC20-16  TL783LM713L

35Risk Management Plan:PMI Risk Management Process

• Identify

• Evaluate

• Develop Response

• Control

36Risk Prioritization MatrixPriority Total Overall Risk Comparison

3 7 High 1. Project goes overschedule

9 1 Low 2. Injury or damage from 120V source 12

10 0 Low 3. Funding delayed 1 2 3 3

1 10 High 4. Delay in parts procurement. 1 2 34 4 4

2 8 High 5. Solving 120V/28V available power problem

1 2 3 45 5 5 5

5 5 Medium 6. Limited financial resources 1 2 3 4 56 6 6 6 6

7 3 Low 7. Loss of a team member 1 2 3 4 5 67 7 7 7 7 7

8 2 Low 8. Unable to source proper 120V DC 1 2 3 4 5 6 78 8 8 8 8 8 8

4 6 Medium 9. Further revisions necessary 1 2 3 4 5 6 7 89 9 9 9 9 9 9 9

6 4 Medium 10. Selected solution found unfeasible 1 2 3 4 5 6 7 8 910 10 10 10 10 10 10 10 10

37Risk Evaluation

PROBABILITYOF

OCCURRENCE

SEVERITY OF IMPACT

LOW HIGH

HIGH

LOW

5 4

6,9 1

10

3 7 8 21. Project over-schedule2. Injury/damage from 120V3. Funding delayed4. Delay in parts5. Solving 120V step-down6. Limited financial resources7. Loss of a team member8. Unable to source 120V DC9. Further revisions necessary10. Selected solution found unfeasible

Legend

38Cost Data

NASA Cost Sharing• Labor $40,915 • Travel $3,000• Equipment $5,000 (TI)• ODCs $5,000• Overhead/Indirect $22,501

(TAMU)_____________________________________________ Total Cost to Sponsor $48,915 $27,501

Actual Project Value 76,416

39Capstone Labor

Total # of Boxes: 133Total # of Work Packages: 95

Expected Number of Man Hours: 2259 HoursResearch: 160 HoursDesign: 363 HoursSimulation: 60 Hours Implementation: 370 HoursTesting: 260 HoursDocumentation: 1046 HoursClose Out: 6 Hours

Gantt Chart

Research

Design

Simulation

Implementation

Testing

Documentation

Close-out

28-Aug-12 17-Oct-12 6-Dec-12 25-Jan-13 16-Mar-13 5-May-13

11/1/12

11/25/12

4/17/13

4/18/13

4/29/13

5/6/13

5/10/13

NWSP Gantt Chart

Duration

Ph

ase

41NASA DeliverablesDate Activity Deliverable1/8/12 Kickoff Meeting Draft System Design Process (SDP)19/9/12 SDR Presentation

Power Point SlidesVideo

29/10/12 PDR PresentationPower Point SlidesVideo

5/12/12 CDR PresentationPower Point SlidesVideo

10/12/12 Final SDP ReportWeekly Project Status Meetings13/2/13 Progress Checkpoint #1 Presentation and PPT Slides

Alpha SchematicAlpha Board LayoutSoftware Hierarchical ChartsTest Matrix

5/3/13 Final Design Review Presentation and PPT Slides3/4/13 Progress Checkpoint #2 Final Schematics

Final Board LayoutSoftware Flow ChartsTest Plan

15/5/13 Progress Checkpoint #3 Final Demonstration 20/5/13 Final Presentation Final Report

Five Smart Plugs15/6/13 Integration with DSH Field Test Plan15/8/13 DSH Integrated Testing Field Test Report15/9/13 Final Acceptance 

42Questions/Comments