P14372 Gate ReviewUpdate Presentation

Kaitlin PeranskiKyle LasherKyle Jensen

Spencer WasilewskiJeremy Berke

Chris Caporale

Power Analysis Response Time Transfer Function Control Algorithm Bode Plot CAD Housing Models Risk Assessment by Component Cost Analysis/BOM/Order Plan Questions for NST

Agenda

Power Analysis

NST ~ 7 ms Data Acquisition ~ .5 ms Software Interpretation and Control ~ 3 ms Communication to NST ~ .2 ms Total Time = 10.7 ms Leaves 2 ms of overhead

Total Response TimeWorst Case

NST ~ 4 ms Data Acquisition ~ .5 ms Software Interpretation and Control ~ 1 ms Communication to NST ~ .2 ms Total Time = 5.7 ms Leaves 7 ms of overhead

Total Response TimeExpected Time

To integrate the gyroscope data, Newton’s Method is applied to incoming data

Transfer Function Derivation

?

Control AlgorithmBack-Up

Computing the correction can also be done by taking the following steps:1) Integrate incoming data and store2) Once there are 32 data points of position

compute an FFT on the data.3) Keep only those frequencies that are above a

certain amplitude threshold.4) Invert the remaining spectrum.5) Compute the inverse FFT.6) Send to NST module.7) Repeat

Control AlgorithmBack-UpThe incoming integrated data will be held in an

array that removes the oldest data to make room for the newest.

x[n-1] x[n-2] x[n-3] ... x[n-32]

x[n]This seems like a foolish thing to do because the only processing being done in the frequency domain is picking out the dominant frequencies and then inverting the resulting spectrum. It uses way more computation time than the proposed method and there is no reason to suspect a more than marginal, if that, increase in performance.

Bode PlotThe peaks happen at 2n / Ts , if a pure sine wave is an input at these frequencies then the integrator will sample at the peaks of the wave and cause the output to increase with out bound

CAD Housing Models

Housing Layout

Housing Layout Side View

Risk Assessment: Battery

Component Risk Effect Cause Likelihood Severity Importance (L*S) Action Owner

Inappropriate source chosen 1 2 2

Thorough power consumption analysis according to test plan

Kyle J

Short circuit 2 3 6Review design layout and

manufacturing quality EE Group

Power consumption larger than anticipated 1 2 2

Thorough power consumption analysis

follwing test planKyle J

Battery Power source failure Device failure

Risk Assessment: Gyroscope

Component Risk Effect Cause Likelihood Severity Importance (L*S) Action Owner

Inadequate sensor specified 1 3 3

Adequate understanding of operating parameters

following test planEE Group

Sensor manufacturer defect 1 2 2

Test sensor according to test plan and replace if

necessaryEE Group

Incorrect biasing 2 3 6 Check build quality (voltages)

EE Group

Gyroscope Poor sensor accuracyPoor vibration

sensing/compensaton

Risk Assessment: Processor

Component Risk Effect Cause Likelihood Severity Importance (L*S) Action Owner

Drive NST module past it's max position

Damaged module Error in code 1 3 3 Turn on failsafe in NST controller

EE Group

Poor data processingInaccurate calculation of

required corrections Poor Algorithm 2 3 6Extensive Algorithm

development and testing according to test plan

EE Group

Send wrong control signal to NST module

Lower than expected vibration reduction

Poor signal encoding 2 3 6 Test control signal encoding

EE Group

Processor

Risk Assessment: Housing

Component Risk Effect Cause Likelihood Severity Importance (L*S) Action Owner

Safety Hazard Injury to user Sharp edges 3 3 9 Break sharp edges after machining

Spencer

Injury to user Case becomes hot 3 3 9

Test running temperature of components before

installation/Benchmark NST power

consumption/use different type of material for covers

following test plan

Group

Damaged components Components become too hot

1 3 3

Test running temperature of components before

installation following test plan

Group

Device OverheatHousing

Risk Assessment: System

Component Risk Effect Cause Likelihood Severity Importance (L*S) Action Owner

Selected compoments out of stock

Redesign mechanical layout

High demand for electrical components

2 2 4 Check frequently, find back up components.

Group

Safety hazard Injury to user Electric shock 3 3 9Check build quality/ Proper grounding/

clearances and creepageEE Group

System

Risk Assessment: Test Bench

Component Risk Effect Cause Likelihood Severity Importance (L*S) Action Owner

Pinch point 1 3 3

Understand testing producedures and

indicate pinch points on test bench using signage.

ME Group

Shock hazard 3 3 9Check build quality;

proper grounding accoding to test plan

ME Group

Can’t drive frequency/amplitude of test

bench

Unable to test required range Improperly specified motor 1 3 3

Peform physical test using prototype before

building.ME Group

Test Bench

Injury to userSafety hazard when using

test bench

Cost Analysis/BOM/Order Plan

1. Can you remove the USB connection from the board and leave contacts to solder wires to?

Questions for NST