Transcript Slide 1
Presented to: 4th Annual GIS Conference Troy University Minimal cost Implementation of an Automatic Vehicle Locating System (AVLS) utilizing legacy radios with custom channel steering modification and COTS GPS modems Presented by: November 16, 2007 Approved for public release; distribution unlimited. Review completed by the AMRDEC Public Affairs Office (November 15, 2007, FN3366) Scott VanDam, PE Consultant Aviation and Missile Research, Development and Engineering Center OVERVIEW GPS Constellation, 10K+ miles altitude GPS Automatic Vehicle Location System GPS GPS Time 2 & Distance 2 Time 1 & Distance 1 Time 3 & Distance 3 Asynchronous Short Burst Data Message Dual fiber AVLS Repeater Periodic Burst 1.5 sec Data Message CES GPS Mobile Antenna TA CES Wireless GPS-150 modem L / A K D TA T A LK RS C S T R RD T D CD Channel steered Motorola Astro W4 radio CES Gateway, Base W4 Receiver, CES Wireless MDC-150 base modem Database Node Dual fiber Base Rx Node EOC node Dual fiber Emergency Operations Center I/CAD with I/Dispatch Fire Truck/Police/other tracked Vehicle 2 Yourfilename.ppt Advantages • • • • • • • • • 3 Increased return on existing radio infrastructure assets Motorola approved GPS (Global Positioning System) accessories Lower life time cost than CDPD/GSM/GPRS systems Location change only and nonpolled configuration minimizes network loading Dedicated AVL repeater independent of normal system voice traffic operations Optional panic/duress vehicle input button available Passive architecture decreases overload protocol bandwidth requirements Vehicle location data available to multiple users in multiple protocols Optional preprogrammed higher speed update rate based on vehicle input, i.e. flasher bar activation Yourfilename.ppt Mobile Configuration GPS GPS GPS Existing vehicle UHF Mobile Transmit/Receive Antenna GPS CES Wireless GPS SM-1575 Receive Radome Antenna RF Optional Vehicle Duress Alarm Input Normally grounded duress lead RF Audio Vehicle Speaker CES Wireless Vehicle Microphone . Motorola Astro Spectra W4 mobile radio (modified connector) 15 pin CES Wireless radio interconnect cable CES modem programmed For Motion Track Passive mode GPS-150 Optional Vehicle Pos. update Rate input radio front mic jack Audio/PTT switch 4 Yourfilename.ppt Repeater Configuration (No changes required to Voice system, an independently operating repeater) Dedicated UHF AVL Fixed Vertical Antenna On Existing Tower RF From vehicle Remote Programming, Configuration, Diagnostics, Upgrades 5 To base . phone line allows remote access to AVL Repeater Dedicated Quantar NB UHF Analog AVL multi-mode Station Repeater, single AVL channel pair allocation Yourfilename.ppt From AVL Repeater Custom AVLS Design Testing To dispatch/database • WPL AVL Test Configuration XIG PDUs via LAN 2nd Ethernet Card (Test & Exercise mode) Windows Service CES GPS data translator software (Optional WPL DIS Switch) TCP/IP UDP via LAN etc Commander Redundant Dual fiber pair SIM Row (Optional Network Switch) RF WPL Roof UHF Omni Antenna (Optional fiber interface) Low loss RG-8 coax CES Wireless Gateway Server Serial Data 25 pin CES Wireless base radio interconnect cable CES Wireless Base Modem MDC-150 MSK encoded Audio . Motorola XTS-5000 (test), W4 operations Base AVL radio Tests Back up, I/CAD networks connections and alternate XML/PDU data type outputs 6 Yourfilename.ppt I/CAD Dispatch enhanced AVLS I/CAD I/Tracker & I/Dispatcher LAN Optional Switch Dual fiber pair Dual fiber pair To database EOC node To Emergency Operations Center I/CAD Operator Network connections 7 Yourfilename.ppt Parts List 8 • • • • MOBILE: (modified Motorola Astro W4 radio) CES GPS-150 integrated GPS modem CES ANT-02 fixed mount GPS radome antenna • CES 240/03-00-0 custom Astro Spectra W4 radio interface cable • • • • • • • • BASE: Dedicated XTL-1500 380-470 MHz trunked base radio with 3600 enhancement (Sharp Quote detail) Dedicated UHF roof mount antenna and coax CES MDC-150 base station modem CES MDC-150 base station modem interface cable CES fleet-Control computer server/base modem controller Intergraph I/CAD computer & monitor for display of map and vehicle positions WPL/Intergraph CES Wireless to I/CAD I/Tracker data/protocol converter windows service software • • • Intergraph I/CAD software Intergraph I/Tracker & I/Dispatcher software modules Yourfilename.ppt Radio Modifications 9 • The W4 radio required a few minor hardware modifications to enable this GPS vendor solution: • • • • Enable radio speaker quieting during GPS data transmission Disable GPS location transmissions when radio is in use on a busy trunked channel Disable GPS location transmissions when radio is currently keyed i.e. PTT depressed for voice traffic Enable radio channel steering to allocated repeater AVL channel • The W4 radio also required the simple programming of an additional AVL channel: • These modifications require approximately two hours each of Motorola certified service shop time • The radios are no longer under warranty so there is no drawback to performing the mods Yourfilename.ppt AVL Testing • • • • • • • • • 10 Busy – Verified that while radio is currently receiving audio, modem will not interrupt PTT – Verified that while radio is keyed for voice, modem will not interrupt Range – Verified over 95% coverage of desired target area with existing W4 at high power level and 600 baud rate Baud Rate - Verified data transmission at 1200 baud rate, currently testing with 600 Accuracy – Tracking tests independently verified position locations as reported by CES modems in the field to within 10 meters Latency – There is an approximate 5 second delay from modem transmission to I/Dispatch map pos. update Transmission time – The radio switches to the AVL channel, transmits the update, and returns to the prior used channel in 1.6 secs (1200 baud rate) Motion Tracking – Range tests were successful showing that the modems transmit position reports only when substantial vehicle position change has occurred Software – All three S/W components tested and work well: – CES Wireless fleet-Control gateway – Intermediary Intergraph/WPL CES Wireless to I/CAD data format translator/forwarder – Intergraph I/CAD with I/Tracker & I/Dispatcher modules Yourfilename.ppt CES Wireless Modem/W4 Radio Interface Timing Diagram MODE Busy Mode Down Arrow > 50 msec and < 0.5 sec returns radio to previously stored radio Channel Mode Down Arrow > 0.5 sec stores current radio ch. Modem programmed 600 msec Settle time before radio checks busy, Modem programmed For 250 msec Modem programmed 100 msec Assumes radio has clear channels and busy remains unasserted HOME PTT falling edge triggered pulse, width set by 74LS122 kRC time constant Home key > 50 msec switches radio to AVL ch. Modem PTT Radio PTT* Modem out PTT, circuit input PTT Circuit out PTT, Radio input PTT Repeater settle time Settle time for radio after switching to AVL Channel, set by modem lead in delay, 10K pot and 1.5 uF cap RC time constant Settle time for circuit generated PTT to charge set by 10K pull up and 1.5 uF cap RC time constant MSK Audio (time) Modem programmed lead in delay set for 750 msec GPS data at 600 baud (1200 baud half this time) 100 msec Per division NOTE: dotted lines are not physical connections between Modem and Radio 11 Yourfilename.ppt