1 PACE LITES PRESENTATION Advisor: Professor Sahakian Andrew Dai Lenore Kaplan Benjamin Mattson Nikhil Sethi

2 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 3 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

14 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 15

Communicating between Xbees and providing readable output 16 Zone Number Encoded Output Range (in) ”-12” ”-20” ”-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 18 Goals Feasibility Testing Cost Range Power Interference

Our prototype showcases a combined sonar and wireless system 19 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 ModuleGateway Board Laptop

20 The prototype proves feasibility

21 Multiplexing Overview

22 Microcontroller (input) Microcontroller (output) Input controls LEDs Sensor Locks Front of carBack of car

23 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

24 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 25

Parts for the virtual build 26

27 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

28 Questions and Comments