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