ECE 477
Digital Systems Senior Design Project
Rev 9/12
Homework 4: Packaging Specifications and Design
Team Code Name: Autonomous Rescue Vehicle Group No. 10
Team Member Completing This Homework: Vipul Vishnu Bhat
E-mail Address of Team Member: vbhat@ purdue.edu
Evaluation:
SEC
DESCRIPTION
MAX
1.0
Introduction
5
2.0
Commercial Product Packaging
-
2.1
<Product #1>
10
2.2
<Product #2>
10
3.0
Project Packaging Specifications
20
4.0
PCB Footprint Layout
10
5.0
Summary
5
6.0
List of References
10
App A
Project Packaging Illustrations
10
App B
Project Packaging Specifications
10
App C
PCB Footprint Layout
10
TOTAL
100
Comments:
SCORE
ECE 477
Digital Systems Senior Design Project
Rev 9/12
1.0 Introduction
The goal of this project is to create an autonomously-navigating robot that can move to
specified coordinates to rescue a lost or injured person. The robot will need to know its current
location and the location of the lost person. This will be accomplished by GPS receivers. The
robot should be able to self-navigate and avoid collisions in the process, using ultrasonic sensors.
Also, in order to achieve meaningful rescue, the robot will need to be able to move quickly.
PSSCs:
1. An ability to move and steer using appropriate motors and drive systems
2. An ability to receive a GPS signal and move toward the given coordinates
3. An ability to detect obstacles and navigate around them using ultrasonic sensors.
4. An ability to monitor the battery level of the robot
5. An ability to use a console to send commands to and receive status information from the
robot
Considering the nature of functionality of the robot, a 6 Wheel Drive All Terrain robot
chassis will be used for this project. For this purpose, a ‘Wild Thumper 6WD All –Terrain
Chassis’, from Dagu Electronics will be used. This document will briefly go over two other
similar chassis from other vendors followed by a detailed explanation on the packaging for the
above mentioned choice. CAD drawings, a PCB footprint layout and packaging specifications
and logistics will be provided in the appendices.
2.0 Commercial Product Packaging
Considering the fact that one of the main features of the project would be to tackle the
issue of traversing on different terrains, this aspect will be used in analyzing two similar
commercial products, i.e. 6WD all-terrain chassis from other vendors.
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ECE 477
Digital Systems Senior Design Project
Rev 9/12
2.1 Product #1
The Super Rover is a 6WD All Terrain chassis manufactured by ‘MINDS-i’
http://www.mymindsi.com/
Specifications:
1. The dimensions are L=23.5”(597mm) x H=7.5”(190mm) x W=16.75”(425mm) and
Wheel Base = 17.5 ”(444mm) when the 6x6 ATV is completely assembled.
2. The rover is driven by a 5000 RPM DC Motor that is powered by a 7.2 Volt 1800 mAh
Ni-Cd Rechargeable Battery.
3. Steering is controlled by a Hitec® HS-485HB Metal Gear Servo motor.
4. 6 Wheel Independent Suspension system.
Pros:

The kit can be assembled into a 6x6 or 4x4 chassis.

Independent suspension enhances all-terrain capability.

Vendor has plenty of upgrades/add-ons available such as remote transmitter modules,
solar panel upgrade modules, etc.
Cons:

The chassis might not have enough room for our PCB and customized add-ons.

The chassis and upgrades are expensive (Super Rover kit price: $589.00)
.
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ECE 477
Digital Systems Senior Design Project
Rev 9/12
2.2 Product #2
The 6WD ATR Base Kit is manufactured by SuperDroid Robots [2].
http://www.superdroidrobots.com/ATRs.aspx
Specifications:
1. The dimensions are L=17.25.5”(438mm) x H=2.5”(63.5mm) x W=12.5”(317.5mm)
2. The robot can be driven by IG32P 24VDC 075 RPM Gear Motors (sold separately)
3. Steering is controlled by a speed differential between the different sides of wheels.
4.
The wheels are axle mounted and are supported using sealed ball bearings
Pros:

The chassis is very rugged and can handle a lot of damage.

Powerful motors are compatible with the chassis.

Motors can be contained inside the chassis and are well protected from rocks, water etc.
Cons:

The motors run off of 24V batteries

The chassis and peripherals are extremely expensive
(ATR kit price : >$1000.00 )
.
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ECE 477
Digital Systems Senior Design Project
Rev 9/12
3.0 Project Packaging Specifications
The Dagu Wild Thumper chassis has a powerful and sturdy build. It is design to operate in
rough terrain, which is crucial in a rescue situation. The 6-wheel drive chassis has independent
suspension for each wheel, allowing it to climb over small obstacles. The motors have 34:1 steel
gearboxes that drive 120mm-diameter wheels with spiked tires [Appendix A]. This kind of
power and traction is great for outdoors. It is also relatively fast for a small prototype vehicle.
We plan to use a 7.2 V battery pack which will allow the robot to reach a top speed of 4.5 mph.
The body of the Dagu Wild Thumper is 380 mm long, 120 mm wide, about 45 mm high, and is
made of 2mm-thick corrosion-resistant anodized aluminum plate [Figure 1]. The top plate of the
body provides a nice open space to install the PCB, ultrasonic sensors, and GPS transceiver
[Figure 3]. Between the wheels, two smaller compartments provide space for the batteries and
battery-monitoring circuit [Figure 2]. Only basic tools are required for the installation, such as
zip-ties and a screwdriver [Appendix B]. The addition of sensors and PCB do not add much
weight to the chassis. The body and wheels together should weigh around 7 lbs and be able to
carry a payload of 11 lbs [Appendix B]. The Dagu Wild Thumper chassis alone will cost $250,
however in comparison to some of the other packaging choices; this is a significantly lower-cost
option.
The other part of our system includes a GPS transceiver and RF Module functioning off of
another PIC32 microcontroller. This will be contained in a hard plastic box having dimensions
100mm x 100mm x 15mm. This unit will be carried by the person who might need to be located
if they lose their way. The box will have room for a 5cm antenna that can be attached to the RF
module if necessary [Figure 4].
This total cost of materials is estimated to be about $643.
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ECE 477
Digital Systems Senior Design Project
Rev 9/12
4.0 PCB Footprint Layout
In order to fit our PCB on the chassis along with the off chip peripherals, the size of the
PCB will be 85mm x 100mm. The area will be more than sufficient to fit the materials listed
below. As quite a few of the peripherals that will be utilized by the robot will be connected
externally, the PCB design will be rather simple. The brain of the robot will be the
PIC32MX120F032B manufactured by Microchip. A battery management IC manufactured by
Texas Instruments will be used to measure the battery level powering the motors. Six H –
Bridges also manufactured by TI will be used to control each of the 6 motors. Finally a voltage
regulator (3.3V) will be used to step down the voltage to power the circuitry [Appendix C]. The
components are listed in the table below along with their dimensions.
Device
Part Number
No. of Units
Dimensions (mm)
Microcontroller
PIC32MX120F032B
2
7.5 x 35
H Bridge
SN75452BDR
6
5.5 x 6.5
Voltage Regulator
LE33CZ-TR
1
4.0 x 5.0
Battery Management
BQ2019PW
1
3.0 x 4.5
IC
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ECE 477
Digital Systems Senior Design Project
Rev 9/12
5.0 Summary
The Autonomous Rescue Vehicle is designed to autonomously locate and navigate to the person
who has activated their GPS transceiver. The reason behind utilizing is a 6WD all terrain
chassis, is to help the robot in travelling through unchartered territory autonomously. The ‘Wild
Thumper 6WD All Terrain’ chassis from Dagu Electronics was not only chosen because of its
all-terrain capability, but also because of the room available on the chassis for custom boards and
peripherals. Besides the microcontroller, the PCB will primarily contain the motor drivers and a
battery monitoring chip. The rest of the components include ultrasonic sensors, GPS
transceivers, RF modules and an Infrared module, which will all be mounted on top of the
chassis. The estimated cost for the project materials is approximately $650.
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ECE 477
Digital Systems Senior Design Project
Rev 9/12
6.0 List of References
[1] Robot Shop. ‘ Dagu Wild Thumper 6WD All-Terrain Chassis (Black, 34:1)
http://www.robotshop.com/productinfo.aspx?pc=RB-Dag-27&lang=en-US
[February 5, 2013]
[2] SuperDroid Robots. ‘6WD ATR Base Kit – Item Details’
http://www.superdroidrobots.com/shop/item.aspx?itemid=741&catid=51
[February 5, 2013]
[3] Minds-i. ‘ 2 in 1 Super Rover kit Description’
http://www.mymindsi.com/shop/cart.php?target=product&product_id=330&category_id=8
4
[February 5, 2013]
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Digital Systems Senior Design Project
Rev 9/12
Appendix A: Project Packaging Illustrations
http://www.robotshop.com/dagu-en.html
Figure 1 - Chassis schematic top, side and front view[1]
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Digital Systems Senior Design Project
Rev 9/12
Figure 2 – Battery Compartments[1]
http://www.robotshop.com/dagu-en.html
Figure 3 – Chassis with PCB and Peripherals
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Digital Systems Senior Design Project
Figure 4 – Mobile box unit
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ECE 477
Digital Systems Senior Design Project
Rev 9/12
Appendix B – Project Packaging Specifications
Vendor
Microchip
Manufacturer
Microchip
Part No.
PIC32MX120F0
32B
Microchip
Microchip
PIC32MX220F0
32B
Sparkfun
ADH
Technology
Maxbotix
GPS-11571
Sparkfun
Digi
International
Inc
XBP09-DPSIT156
Sparkfun
SIMEREC
SEN-08753
Sparkfun
Sparkfun
COM-10280
Pololu
Pololu
Pololu
Pololu
1562
2235
Home
Depot
Pololu
Energizer
250355
iMax
2260
Digi-Key
STMicroelect
ronics
Xiamen
Ocular
LE33CZ-TR
Sparkfun
Sparkfun
SEN-08504
Description
32-bit
microcontroller
(21 Pins)
32-bit
microcontroller
(19 Pins)
GPS receiver
Tools
Soldering Iron
Ultrasonic
Sensor
RF module
LCD-00255
Infrared
receiver
Infrared
controller
6WD Chassis
7.2V Battery
Pack
9V Battery
Pack
Battery
Charger
Voltage
Regulator
LCD Screen
Unit Cost Qty
$2.23
1
Total Cost
$2.23
Soldering Iron
$2.23
1
$2.23
Soldering Iron
$39.95
2
$79.90
Soldering Iron
$27.95
3
$83.85
Square Tube
of length
300mm,Sheer,
Screwdriver
and screws
$54.95
2
$109.90
Soldering Iron
$9.95
1
$9.95
None
$3.95
1
$3.95
Zip-ties
Zip-ties
$249.95
$17.29
1
1
$249.95
$17.29
Zip-ties
$9.97
1
$9.97
None
$49.95
1
$49.95
Soldering Iron
$0.70
1
$0.70
Soldering Iron
$13.95
1
$13.95
Digi-Key
Texas
Instruments
SN75452BDR
Bridge Driver
Soldering Iron
$0.54
6
$3.24
Digi-Key
Texas
Instruments
BQ2019PW
Battery
management
IC
Soldering Iron
$5.80
1
$5.80
Table 1
Total Cost = $ 642.86
Total Weight = 3.3 Kg ( 7.27 lb )
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ECE 477
Digital Systems Senior Design Project
Appendix C: PCB Footprint Layout
Figure 5
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Rev 9/12