PACE LITES PRESENTATION

canolaokahumpkaΗλεκτρονική - Συσκευές

2 Νοε 2013 (πριν από 3 χρόνια και 7 μήνες)

96 εμφανίσεις

1

PACE LITES
PRESENTATION

Advisor: Professor Sahakian

Andrew Dai

Lenore Kaplan

Benjamin Mattson

Nikhil Sethi

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PACE global vehicle


PACE is a global
collaborative project
aimed at designing a new
vehicle for the emerging
market


Universities across the
world are assigned
different sub
-
systems



Northwestern is designing the
electrical sub
-
system

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Goals


Safety


Minimize
weight


Efficiency

Front and Rear
End Collision
Avoidance

Provides
additional
safety features

Sonar
technology

Wireless
Communication
Network

Communicates
relevant
information

Zigbee

Standard
Radios

Modular
Multiplexing
System

Minimizes
weight and
increases
efficiency

Microcontrollers
MOSFETS

4

Sonar design utilizes transducers
located inside the bumpers


Powerful range finder


Drivers receive alerts of
objects quickly approaching


Onboard processing

An overhead view of the wave propagations from the
front and rear of the vehicle.

Each transducer will be
housed within the bumper,
keeping a smooth surface
across bumper face.

5

Design detects objects at short and
long ranges

Specs:


3 Ultrasonic transducers


Center transducer short, wide
range


Outside transducers long,
narrow range


Senscomp 6500 ranging
module board


Basic stamp microcontroller


An overhead view of the range covered
by each transducer. Short range is
emphasized with parking, long range is
focused on collision avoidance.

The sonar works in tandem with the
microcontroller in a multi
-
step process

The sonar system is controlled by the microcontroller,
which is integrated into the vehicle’s engine control unit
(shown in yellow).

The microcontroller runs the ranging module, which supplies
source voltage to the transducers.

Step 1: Begin the sequence

-

Microcontroller (MC)
tells sonar receiver
board to send 400 volt
pulse to relay circuits

-

MC connects first relay
circuit

-
MC starts timer

The microcontroller readout (highlighted in yellow) allows the driver to monitor the
sequence from beginning to end.

Step 2: Transducer emits wave pulses

-

400v arrives at transducer

-

Creates current in metal casing

-

Causes diaphragm to flex

-

Flex creates ultrasonic wave

Step 3: Reflected waves indicate object is
present

-
Wave encounters object

-
Small portion reflects

-
Reflection returns to
transducer, causes slight flex

-
Flex induces voltage

Step 4: The microcontroller receives
detection signal and ends sequence

-
Return pulse travels
down original line to
RB

-
RB tells MC an object
has reflected wave

-
MC stops timer,
records time

Step 5: The microcontroller runs code to
decipher time to collision

The prototype functions both attached
and independent of the vehicle

13

Intervehicle communication allows
increased awareness between vehicles


Zigbee wireless system allows
inter
-
car communication


System can warn others of
weather, incoming traffic,
construction


Car

Computer


XBee

Module


Car

Computer


XBee

Module


LCD Display

LCD Display

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The Zigbee standard offers benefits in
range, and power


Alternate technologies


Wifi



300ft range


Bluetooth


3ft range


Specs


Digi

Xbee

PRO modules


<$25


<1W


5000ft range




Wireless prototype works on a
modular basis


Components


XBee modules


ARM processor


Blackbox input


Host machine

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Communicating between Xbees and
providing readable output

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Zone
Number

Encoded
Output

Range
(in)

1

1000

0”
-
12”

2

1100

12”
-
20”

3

1110

36”
-
120”

4

1111

120”+


Converting output from
sonar for transmission


Describing Zones to user

Testing the range and efficiency of the
wireless system


Tested RSSI (dBm)


Transmitted 64bits


Was able to operate at a range
of 1 foot to 120 feet.

17

Prototyping enabled us to test for
feasibility, range, robustness

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Goals


Feasibility


Testing


Cost


Range


Power


Interference

Our prototype showcases a combined
sonar and wireless system

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BASIC stamp
microcontroller


12V Battery

5V
Regulator


SensComp 6500
Ranging Module



Digi Xbee Module



BJT
Switches


400V
SS
Relays

Environmental
Grade Sonar
Transducers


Coaxial
Cables


Digi Xbee Module




Gateway

Board



Laptop



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The prototype proves feasibility

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Multiplexing Overview

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Microcontroller
(input)

Microcontroller
(output)

Input controls

LEDs

LEDs

Sensor

Locks

Front of car

Back of car

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Multiplexing allows large minimization
of vehicle’s wires


MOSFETs


Handles lots of current (60 A)


No moving parts


Wire Gauge


Less power loss for 8 gauge


Easier assembly


PIC microcontroller


Programmable communication


40 I/O

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Multiplexing connects all components
in a modular fashion

Multiplexing will:


Lower



wire cost



power loss


Connect all electrical
components in PACE car

Multiplexing Reduces Installation
Time and Cost


Less wires mean less
assembly time


Boothroyd Dewhurst
DFMA provides methods
of predicting assembly
time


Example


Assembling Wires in wire
loom


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0
5
10
15
20
25
With Multiplexing
Traditional Wiring Harness
Seconds

Time Saved by
Shortening
Wires (per wire)

Parts for the virtual build

26

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Next Steps


Design sonar and wireless circuit boards
specifically for PACE design


Create user interface


Multiplexing


Program so that components are plug and play


Universal connections


Testing


Sonar Arrays


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Questions and Comments