Wireless Test Instrumentation for Rotating Parts

ECE 193 Advisor: Rajeev Bansal

Olivia BonnerDavid Vold

Brendon RuschMichael Grogan

ME 32 Advisor: Robert GaoKyle Lindell

Andrew Potrepka

∙Problem Statement∙Solution∙Parts Ordered∙Parts To Be Ordered∙Improvements To Electronics∙Energy Harvesting Options∙Battery Options∙Future Tasks∙Budget∙Timeline

Outline

● Sikorsky has asked the team to come up with a proof of concept for a wireless sensing system.

● Benefits of a Wireless System:

○ No long, heavy wires

○ No slip rings

○ Overall weight of system reduced● Challenges of a Wireless System:

○ Powering the system○ Large temperature range

■ -65 F to 400 F

Problem Statement

Electronics Compartment:● Size: 1.5” diameter x 5.1” long● Temperature Range: -65ºF to 300ºF

Sensor(s):● Minimum of 2 sensor types● Temperature Range: -65ºF to 400ºF

Rotating Speed of Tail Rotor Shaft:● 1200 RPM

System Requirements

Figure 1. System Block Diagram

System Block Diagram

Figure 2. Power Circuitry Block Diagram

Power Circuitry

● Sensor(s):○ Infrared thermometer○ Ambient thermometer○ Accelerometer○ Microphone

● Microcontroller:○ Arduino Nano v3.0

● Transceiver:○ WiFly Module

Ordered Parts

● Energy Harvesting Method

○ Brushless Generator

● Power Circuitry

○ Rectifier

○ Switching Regulator

○ Charging Circuit

● Battery

○ Lithium cells (Li-Ion, Li-Poly)

Parts To Be Ordered

● Previous Design:○ Custom built,

expensive to replace/modify

○ No documentation

○ Limited connectivity

○ Missing components

Improvements to Electronics

● Our Design:○ Greater

connectivity○ Small size○ Affordable○ Greater

available documentation

● New Custom Design:○ Get only what we need in the size we want○ Prohibitively expensive (cost > $1300)○ Only can afford one○ Little documentation

● Off the shelf options (Arduino, Teensy):○ Excellent connectivity○ Available in our size○ Open sourced, excellent documentation○ Affordable (cost < $40)

Electronics Options

● Small, low power evaluation board

● Plenty of documentedprojects and codeon website

● Many compatible sensors/add ons

for sale

Arduino Nano V3.0

● Triple axis accelerometer

● Electret microphone

● Ambient thermometer

● Infrared thermometer

● Low-power wifi module

Sensor/Add-on Choices

● Thermoelectric- Insufficient power from

available temperature gradient

● Piezoelectric- Too large- Insufficient power- Needs vibrations within a

narrow range of frequencies

● Magnetic- Sufficient power- Requires low KV motor,

gearing, or a step-up regulator

- Necessitates use of gravitational torque

Energy Harvesting Options

● NiCd and NiMH- Quick and simple charging- Durable- Poor energy density- 1.2V per cell- Smaller temperature range- Memory (NiCd only)

● Lithium cells (Li-Ion, Li-Poly)- High energy density- 3.7V per cell- Various shapes available (Li-Poly)- Wider temperature range- More complex charging- Less durable

Battery Options

Battery Charging Circuit Options

∙ Uses transistor, variable regulator, 2 capacitors, potentiometer, 1 Ohm/1 Watt resistor, 3 normal resistors

Create our own:

Battery Charging Circuit Options

∙ Chip Features:∙ Charger Plus Pack Protection in One IC∙ Low Operating Current (550nA)∙ Near Zero Current (<0.1nA) Low Battery Disconnect Function to Protect Batteries

from Over-Discharge∙ Pin Selectable Float Voltage Options: 4.0V, 4.1V, 4.2V∙ Ultralow Power Pulsed NTC Float Conditioning for Li-Ion/Polymer Protection∙ Suitable for Intermittent, Continuous and Very Low Power Charging Sources∙ High Battery Status Output

Using Power Management IC Chips:

Battery Charging Circuit Options

∙ Chip Features: combines high-accuracy current and voltage

regulation,battery conditioning, temperature monitoring, charge

termination, charge-status indication, and AutoComp charge-rate

compensation in a single 8-pin IC.

Using Power Management IC Chips:

∙Different circuit – different layout inside capsule

∙Mount the rig to change pitch angle

∙Second set of wired sensors for data comparison

Test Rig: Potential Modifications

Tasks for Next 45 Days

∙Assemble and test Arduino Nano with sensors

∙Assemble and test Wi-Fi module

∙Order: motors, batteries, charging circuit equipment

∙Make modifications to test rig as necessary

Budget

Arduino Nano $35

Mini B USB Cable $4.50

Xbee Add-on Board $25

Wifi module $35

Nano Protoshield $15

Triple Axis Accelerometer $15

Infared Thermometer $20

Thermometer $1.50

Electret Microphone $8

DC Generator (Estimated) $20

Power Management Circuitry (Estimated) $30

Battery (Estimated) $100

Printed Circuit Board (Estimated) $200

Total $509

Purchase Breakdown

● Budget: $2,000

● Spent to Date: $159

● Additional Estimated Costs: $350

● Estimated Surplus: $1,491

Timeline

Questions

Student Assessment

● Presentation Style

● Readability of Material

● Team results and deliverables are clear?

Grade A, B, or C with clicker