Power BotGroup 2

Luke CremeriusJerald Slatko

Marcel Michael Tarik Ait El Fkih

Sponsored By:

Aeronix Inc.

Project DescriptionAutonomous Robot with onboard auxiliary

batteryUsed to provide supplemental power to mobile

devices (laptops, mobile phones…etc)Uses onboard navigation algorithms to

navigate to users locationHas iOS application to provide robot statistics

and is used to control PowerBot’s movements.

Project MotivationBattery life longevity in mobile devices is a

constant issue.Wanted to create a charging solution that could

charge the device without inconveniencing the user.

The device would be simple to use, allowing for easy adoption into a users everyday routine.

ObjectivesPowerBot will be able to navigate autonomously

to a users location.PowerBot can be remotely controlled by user

input, through the use of an onboard camera and the provided iOS application.

PowerBot will contain a battery used to charge external devices through the use of USB, DC, and inductive charging.

SpecsWill be at most 36” longMax speed of 5 mphBattery life of minimum 24 hoursAble to charge mobile phone from 0% - 100% without

needing to recharge internal batteriesWill re-charge internal batteries through in-home AC

and/or via onboard solar panel.Will navigate to the user autonomouslyCan be operated via manual control

Software OverviewEmbedded software for navigation and power

controliOS application for controlling PowerBot Wi-Fi module embedded software for

communication with iOS app

iOS Application

Embedded NavigationAlgorithm

Motor Control

Power Manageme

nt

SoftwareLayout

MCU Embedded Software

Sonar Sensors

Servo Motors

Solar PanelCharging

Ports

iOS AppWritten in Objective-C using

Xcode 4.4Offers multiple options for

PowerBot:SettingsNavigationManualStatistics

iOS ViewsEach view contains a

separate viewController, allowing each tab to contain a unique layout of buttons and fields to be presented to the user.

socketConnect

Creates socket to IP Address on a given

port

sendMessage

Sends message from output buffer

receiveMessage

Receives mesassage from

input buffer

parseMessage

Analyzes message to determine

function

NSOutputStream NSInputStream

Message Instance

Wi-Fi Communication• Used as the primary mode of communication between PowerBot

and the iOS Application.

• 802.11 used as physical layer communication, with sockets used for higher level communication

• RN-131 TCP/IP stack facilitates simpler TCP and UDP data transfer between PowerBot and its iOS App.

Application Layer

MCU - Serial

802.11 - Socket

iOS - Serial

802.11 Socket

Application Layer

Embedded Software iOS Software

Wi-Fi Module - RN-131 • The Microchip RN-131 provides a complete Wi-Fi solution for

onboard communication with PowerBot

• The integrated TCP/IP stack within the RN-131 allows for easier implementation of sockets and passing data via TCP/UDP

RN-131 – Power Consumption• Provides low power

• communication solution

• 4uA Power Consumption when idle

• 40 mA while active and connected

• 140 mA Power while active and transmitting

Power

PIC 32

Inductive Charger

GPS Compass Serial Camera

DC Motors

Obstacle Avoidance

5V Reg

3.3V Reg

Wireles

16V

14V

5V

3.3V

14V Reg

Servo Motors

Battery Requirement12 volt batteriesAt least 2.4 AhDeep Cycle for increased usage timelow internal ResistanceHigh Depth of DischargeLightweight

SPECIFICATIONS Ni-Cd Ni-MH Li-ion Li-Po

Energy density (W·hr/kg) 40–60 70-90 100-160 130-200

Capacity (Amp-hr) 1 2.4 2.8 12.6

Internal resistance (mΩ) 100-200 200-300 100-200 200-300

Nominal voltage (V) 1.2 1.2 3.6 3.7

Discharge rate Flat Flat Flat Flat

Recharge life 500-700 cycles 600-1000 >600 >1000

Disposal Must be recycled Recyclable Recyclable Recyclable

Charge/discharge efficiency 70-90% 66% 80%-90% 99.80%

Cost ($/Whr) 2 2.75 2.5 2.8-5

Battery Choice

Lithium Polymer Battery Li-Pol 18650 Battery

22.2 v (working)25.2 V (peak)15 V (cut-off)

Reasons for choosing• High energy density (Wh/kg)• High energy/dollar (Wh/$)• High charge efficiency (80-90%)• Low self-discharge

Alternative Power SourceSolar Panel:

Environmental ImpactFinancial BenefitsEnergy Independence

Solar Panels Specifications   Monocrystalline Polycrystalline Thin film

Power 10W 10W 10W

Open circuit voltage 21.5 21.4 24.2

Short Circuit Current 0.64 0.68 0.84

Maximum Power Voltage 17.5 16.8 17.3

Maximum Power Current 0.57 0.6 0.64

Efficiency 15% 12.5% 6.3%

Cost/W 10-11 8.5-9.5 10

Solar Power Selection Details Solar Panel Type Monocrystalline

Manufacturer INSTAPARK

Power 10 W

Maximum Voltage Power 17.5

Maximum Current Power 0.57A

Open Circuit Voltage 21.95 V

Cost $39.95

Increase the efficiencyIncrease the size of the solar panelImplement a tracking system

Single axis tracking system Dual axis tracking system

Single Axis Control System Overview

Ambient light

Photoresistor MSP430 Longitude

orientation

Dual Axis Control System Overview

Ambient light

Photoresistor MSP430

Latitude orientation

Longitude orientation

comparison and decisionDual axis require more maintenance Extra cost for buying an extra motor or

actuatorComplexity 6% extra efficiency

How to implement RotateFixe the other angle At 15degree to have less losses

Servo motor Specification Control System: +Pulse Width Control 1500usec Neutral Required Pulse: 3-5 Volt Peak to Peak Square Wave Operating Voltage: 6.0 Volts Operating Speed : 0.15sec/60 degrees at no load Stall Torque: 51 oz/in (3.7 kg/cm) Current Drain: 7.7mA/idle and 180mA no load operating Dimensions: 1.57" x 0.79"x 1.44" (40 x 20 x 36.5mm) Weight: 1.52oz (43g) Price: $12.95