Reproduce demodulated RF signal to control the car

Remote Control Sensor Car for Vehicle to Vehicle Communication TestingJulian Santorelli, Robert Morawski and Tho Le-NgocDepartment of Electrical & Computer Engineering, Broadband Communications Research Lab, McGill University

Motor vehicle accidents take thousands of lives a year inCanada aloneSeveral studies have shown up to 60% of these crashescould be avoided if the driver was warned just a half secondsooner[1]Large number of such crashes are due to driver factors[1].Drivers suffer from perception limitations, resulting in largedelays propagating emergency warnings

Short term Goal: Create a prototype for a sensor car.Equipped with ultrasonic sensor and Bluetooth that can becontrolled remotely by the userLong Term Goal: Implement a mesh network with multiplesensor cars to test Vehicle to Vehicle(V2V) communicationin a controlled environment

Wireless CommunicationZigBee communication protocol was used. It is Based on theIEEE 802 standard. Used for low power, short rangetransmission with relatively low data rates. Designed for longbattery life.

•ZigBee Coordinator - Selects channel parameters,allows nodes to join, can route data, has to be awake•ZigBee Router- Must join networkbefore routing data, can allow othernodes to join, always awake•ZigBee End device – Transmit orreceive data from parent only, can sleep

Mesh network: Each node must be ableto transmit and receive data from every other node

♦ Results

Waspmote board and gateway by Libelium

Xbee ZigBee RF modules by DIGI International inc

RC Car and Ultrasonic sensor

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♦ Materials & Methods

Figure 2: Image taken from[3]

Figure 3: Series 2 and Series 2 Pro , taken from [4]

Stud

y PC

B To interface Sensor node with RC car

Repr

oduc

e ou

tput For full control of car

via microcontroller

Crea

te N

etw

ork Set up Waspmote

device as a mesh network

Calib

rate

sen

sors Send raw data back

from car sensors to the gateway

Crea

te u

ser

cont

rol On screen GUI or

via Accelerometer remote control

Interface between Sensor Node and RC Car

Figure 5 :PWM Signal, taken from [6]

Simple one wire interface. Feed the reproduced signal fromWaspmote board’s digital output directly to the IC on the car’s PCB1,2,3 are constants

5 controls speed4 controls turning6 is fixed length of signal

Easy implementation and easy to repeat over many cars No need to add or remove hardware on PCB

Ford is currently testing V2V communication using NFC andWiFi as part of its intelligent cars program.This System would give drivers advanced warning onupcoming accidents, warn drivers if there is an oncoming carat a difficult or obstructed intersection or let them know ofsudden changes in speed from cars in front of them.

Set up Waspmote device in a Mesh topology with the corresponding node types

Figure 7: Network set-up

Network Creation

ZigBee Router

ZigBee Coordinator

ZigBee Router

Program network joining parameters on Xbeemodules; Channel, PANID, stack profile etc. Coordinator scans nearby nodes and sends outmessage for the corresponding nodes to join Once the network is set-up information can flowfrom computer(the gateway) to either of the routers.As well, each router can route the message to theindented device if it is out of range

Smart routing handled by Waspmote API

Figure 8 : Network parameters displayed with X-CTU Software

ZigBee Routers are used so cars can routewarnings or messages they receive to the next node

Figure 9 : Routing protocol employed by Waspmote API, Taken from [7]

User ControlAccelerometer Samples Accelerometer Values at 160 Hz and performs minor filtering via the APIConverts the larger Accelerometer values, both X and Y, to a smaller subset of values Sends data at very frequent rate to the other Waspmote, Waspmote processes small subsetof values via a lookup table kept on the flash memory, then carries out associatedinstructionOn Screen Loads a user chosen map(to scale) and creates ½’ by ½’ grid Sets up serial communication with Waspmote GatewayOnce a path is drawn, it is analyzed, broken down into a subsetof very simple commands, formatted to fit Waspmote’s packetdesign, then sent serially to the gatewayOnce the packet is sent, the Waspmote on the car processes thecommands and executes them in succession

♦ Future Application

V2V communication trials are going on in 6major cities in the US, headed by theirDepartment of Transportation.Such systems when implemented can reduce upto 80% of unimpaired accident7 and can evenrelieve traffic congestion as well as pollution byoffering real-time traffic and alternate routes

Limitations and issues Need to constantly drive and produce a PWM signal tocontrol car, requiring heavy use of the network if real timeFuture Work On screen GUI control to work in real time, both sendingdata and receiving data from the sensor node. This wouldrequire heavier processing needing an external application Create multiple sensor cars and test communication ofthe car’s data between them, test if cars can avoid each otherbased on position and ultrasonic data

♦ Conclusion

[1] C. D. Wang and J. P. Thompson. Apparatus and method fo motion detection and tracking of objects in a region for collision avoidance utilizing a real-time adaptiveprobabilistic neural network, 1997. US.Patent No. 5,613,039.[2] Robert Poor, Ember Corp., Wireless Mesh Networks, http://www.sensorsmag.com/networking-communications/standards-protocols/wireless-mesh-networks-968,2003[3] http://www.libelium.com/products/waspmote[4] http://www.digi.com/products/wireless-wired-embedded-solutions/zigbee-rf-modules/zigbee-mesh-module/xbee-zb-module#overview[5] http://www.geeky-gadgets.com/geeky-toys-the-rc-spy-car/[6] Chris Leung, Remote Control Car Interface Solutions, 2008[7] http://portal.ember.com/node/682[8] http://electronicsbus.com/vehicle-to-vehicle-wireless-communication-system-wifi-nfc/[9] Viknesh Vijayenthiran. Six Cities Named For New Vehicle-To-Vehicle (V2V) Communications Trials. http://www.motorauthority.com/news/1060101_six-cities-named-for-new-vehicle-to-vehicle-v2v-communications-trials. 2011,

♦ References

Figure 1: Mesh network [2]

Figure 4: Ultrasonic sensor and RC car

Taken from [3]

Taken from [3]

Taken from [5]

Figure 6: One wire interface to PCB

Figure 10: Accelerometer control

Figure 11: Guifor Pc control

Figure13: Ford V2V assistance, taken from [8]

Taken from [9]

♦ INTRODUCTION