1. NDIA 3 rd Annual Intelligent Vehicle Systems Symposium, June 9 - 12, 2003 1 Robotic Path Following using Navigational Unattended Ground Sensors (NAV-UGS) A Work in Process Report NDIA 3 rd Annual Intelligent Vehicles Systems Symposium Grand Traverse Resort and Spa Traverse City (Acme), MI June 12, 2003 Anthony J. Giovanetti, Albert Shyu and Lou McTamaney (UDLP) David Baughman (Honeywell) Philip Frederick (U.S. Army TARDEC) William Merrill and Guillaume Rava (Sensoria Corporation) Kris Alluri (SEI)

2. NDIA 3 rd Annual Intelligent Vehicle Systems Symposium, June 9 - 12, 2003 2AgendaAgenda  Participants  Theory of operation/benefits  Simulation parameters and results  Experimental setup  Preliminary experimental results  Test plan

3. NDIA 3 rd Annual Intelligent Vehicle Systems Symposium, June 9 - 12, 2003 3ParticipantsParticipants Company/AgencyCapabilitiesResponsibilities  Combat vehicle development and integration  System development, integration, and test  Driver’s display development Defense & Space Electronic Systems  High-accuracy inertial navigation systems for ground vehicles  TALIN TM 4000 INS and navigation algorithm and error analysis  Robotics and unmanned vehicles  HMMWV manned surrogate platform  Wireless embedded systems and networking technology  Hybrid acoustic and RF ranging system  Software design, code and unit test  Software partitioning  Navigation computer software

4. NDIA 3 rd Annual Intelligent Vehicle Systems Symposium, June 9 - 12, 2003 4 Theory of Operation/Benefits RF timing and sequencing NAV-UGS What is it and what are its benefits?   An alternative to vision- or GPS-based path followers for unmanned vehicles   A driving aid for manned vehicles   High precision path following is possible, i.e., 0.5 m, 3dRMS   Works in confined quarters urban ops   Does not congest RF spectrum and less susceptible to jamming   Works with legacy systems   Adapts to FCS UGS   Marker/follower do not have to be on path at same time What is it and what are its benefits?   An alternative to vision- or GPS-based path followers for unmanned vehicles   A driving aid for manned vehicles   High precision path following is possible, i.e., 0.5 m, 3dRMS   Works in confined quarters urban ops   Does not congest RF spectrum and less susceptible to jamming   Works with legacy systems   Adapts to FCS UGS   Marker/follower do not have to be on path at same time Path marker or follower What does it use and how does it work?   Uses a path marking vehicle, precision INS, and ground-based sensors (NAV-UGS)   Marker vehicle places NAV-UGS along path and encodes each with time/position coordinates derived from the ranging algorithm in terms of marker’s INS reference frame. May also encode terrain data.   Follower vehicles interrogate NAV-UGS and use encoded data to eliminate their accumulated INS errors to closely steer the marker’s path What does it use and how does it work?   Uses a path marking vehicle, precision INS, and ground-based sensors (NAV-UGS)   Marker vehicle places NAV-UGS along path and encodes each with time/position coordinates derived from the ranging algorithm in terms of marker’s INS reference frame. May also encode terrain data.   Follower vehicles interrogate NAV-UGS and use encoded data to eliminate their accumulated INS errors to closely steer the marker’s path High-accuracy acoustic ranging (1dRMS = 10 cm)

5. NDIA 3 rd Annual Intelligent Vehicle Systems Symposium, June 9 - 12, 2003 5 How NAV-UGS Path Following Works   Marker vehicle dispenses NAV-UGS when INS drift error exceeds 0.5 m.   Marker triangulates its position with respect to NAV-UGS using transceiver.   Marker encodes NAV-UGS position with respect to its location into NAV- UGS RAM. May encode other information, including terrain data.   Follower detects NAV-UGS, triangulates NAV-UGS location and compares this location to that stored by marker in RAM.   Follower uses difference in NAV- UGS location measurements to synchronize INS and steer closer to marker’s path.

6. NDIA 3 rd Annual Intelligent Vehicle Systems Symposium, June 9 - 12, 2003 6 Simulation Runs—Parameters and Assumptions  Simulates navigation error only; no vehicle control error  Vehicle travels 55 kph constant speed due north  Equally spaced NAV-UGS with 60-m cross track offset  TALIN TM 4000 INS with 0.25% accuracy per distance traveled, vehicle motion sensor (VMS) aiding, but no GPS  Vehicle communicates with one NAV-UGS at a time  One valid measurement/sec per NAV-UGS N X X (60,Y 0 +d) NAV-UGS Vehicle (60, Y 0 ) y x X (60,Y 0 +Nd)

7. NDIA 3 rd Annual Intelligent Vehicle Systems Symposium, June 9 - 12, 2003 7 Simulation Runs—Results for constant 500 m spacing between NAV-UGS 90 m Comms Range INS only INS + VMS INS + VMS + NAV-UGS 0.5 m allowable path error Meets requirement Better than requirement Ranging accuracy = 50 cm Ranging accuracy = 20 cm Path Error (m) 90 m Comms Range 200 m Comms Range

8. NDIA 3 rd Annual Intelligent Vehicle Systems Symposium, June 9 - 12, 2003 8 Technology Demo Objectives  Demonstrate INS aiding using ground-based navigation beacons ► Objective NAV-UGS will use miniature, developmental RF tag that provides high accuracy clock, narrow pulsewidth, and high bandwidth for cm-accuracy ranging over short distances ► For interim, use hybrid RF/acoustic COTS ranging system from Sensoria Corporation*  Show accurate path marking and following at 55 kph over a 3-km-long urban course *Corrected for Doppler effects

9. NDIA 3 rd Annual Intelligent Vehicle Systems Symposium, June 9 - 12, 2003 9 Comparison of Tech Demo and Objective Solutions Objective RF Tag Interim hybrid RF/ acoustic transmitter Parameter NAV-UGS Follower Vehicle Number of Vehicles Speed/ Separation Tech Demo RF/acoustic hybrid Surrogate MGV with human driver acting as robotic controller One; marker/follower are same. Recycle INS power to simulate follower. 55 kph / 3 km Objective RF tag embedded in UGS UGV follower Unlimited; many markers and followers possible. 65 kph / > 200 km 12 cm 1 cm x 2.5 cm

10. NDIA 3 rd Annual Intelligent Vehicle Systems Symposium, June 9 - 12, 2003 10 Tech Demo Software Design Sensoria NAV-UGS Honeywell TALIN INS Operator Display & Controls System Controller Follower Algorithm Range Velocity Est. Bearing & Range Setup Data Position, Velocity & Attitude Mode (marker | follower) Driver Guidance Follower Path INS/NAV-UGS Data, Path Definition Start, Stop Marker Mode Algorithm   Reads INS/NAV-UGS data   Computes/records path segment data   Upon reaching destination, computes polynomial curve for all path segments Follower Mode Algorithm   Receives path definition   Reads INS/NAV-UGS data   Computes cross track & velocity errors   Displays errors to driver in user friendly format

11. NDIA 3 rd Annual Intelligent Vehicle Systems Symposium, June 9 - 12, 2003 11 Physical Configuration Vehicle Motion Sensor (VMS) Speedometer cable between transmission & VMS Honeywell TALIN TM INS Microphones and windscreens (4) DGPS scoring system antenna & receiver Sensoria RF antenna & Gateway Power distribution electronics Laptop NAV PC Driver’s display M1037 HMMWV

12. NDIA 3 rd Annual Intelligent Vehicle Systems Symposium, June 9 - 12, 2003 12 Start/ End 3 km Test Course  Urban environment with sharp turns and abandoned buildings  Includes overhead obstructions that block GPS signal  Minimum/maximum path speeds = 16/55 kph  Deploy NAV-UGS every 100 m 500 m

13. NDIA 3 rd Annual Intelligent Vehicle Systems Symposium, June 9 - 12, 2003 13 Driver’s Virtual Environment and Display Heading indicator & turn coordinators (plan and out-the-window views) Laptop NAV computer Human driver serves as robotic controller maintaining vehicle heading and speed using only display commands and without reference to horizon Speed indicator (and set point) Driver’s compartment enclosed in blackout cloth

14. NDIA 3 rd Annual Intelligent Vehicle Systems Symposium, June 9 - 12, 2003 14 Virtual Environment and Display Approach  UDLP real-time Interactive Vehicle Model (IVM) simulates dynamics ► Six DOF for vehicle chassis—3 translational and 3 rotational ► One DOF for each wheel—translation perpendicular to chassis ► Suspension spring and damping ► Tire-to-ground spring and damping ► Propulsion system forcing function uses throttle, brake, and steer inputs; outputs engine and wheel speeds  Control algorithm uses Matlab Simulink ► Generates speed (throttle, brake) and steer commands for driver to follow prescribed path  IVM displays vehicle track in two formats: out-the-window and plan view

15. NDIA 3 rd Annual Intelligent Vehicle Systems Symposium, June 9 - 12, 2003 15 Virtual Environment Demonstration (.avi file—click to play)

16. NDIA 3 rd Annual Intelligent Vehicle Systems Symposium, June 9 - 12, 2003 16 Path Follower Scoring Procedure for Dynamic Testing  Use COTs NovAtel DGPS surveying system to precisely locate each NAV-UGS position on the test course (expected static accuracy + 2 cm true position)  Synchronize navigation system time to scoring system GPS time (1 ms time difference ~ 2 cm position error)  Calculate NAV-UGS measurement error ► Calculate true range from surveyed NAV-UGS locations and true trajectory ► Subtract true range from NAV-UGS computed range ► Post process DGPS data to obtain vehicle true dynamic position (expected accuracy within +4 cm true position)  Isolate NAV-UGS measurement error from NAV algorithm ► Rerun navigation algorithm using recorded INS data and true range measurements  Isolate guidance and control errors ► Calculate NAV algorithm position estimates based on NAV-UGS locations, segment path distance and downtrack/crosstrack errors ► Subtract NAV algorithm estimated position from true positions to find guidance and control errors

17. NDIA 3 rd Annual Intelligent Vehicle Systems Symposium, June 9 - 12, 2003 17 Preliminary Results: NAV-UGS Static Ranging Precision* Nominal range to NAV-UGS (m) Number of samples 1 dRMS error (cm) R 90 (cm)** 5596.310 6188.313 911912.4 *Outdoors with 5 kt winds; NAV-UGS on ground; microphones 1 m above ground; distance to NAV-UGS measured with tape and then compared to acoustically-derived range **90% of all events Measured precision is sufficient to maintain vehicle paths within 0.5 m Meets requirement Ranging accuracy = 20 cm 90 m Comms Range 0.5 m allowable path error 20

18. NDIA 3 rd Annual Intelligent Vehicle Systems Symposium, June 9 - 12, 2003 18 Preliminary Results: NAV-UGS Static and Dynamic Ranging Precision* *Doppler corrected **90% of all events. Dynamic dispersion computed about INS predicted position, corrected for any initial offset error in locating NAV-UGS in INS coordinates. Measured precision is within 20 cm up to 35 kph Dynamic Static

19. NDIA 3 rd Annual Intelligent Vehicle Systems Symposium, June 9 - 12, 2003 19 Test Plan  Prepare the test course ► Use NAV simulation to plan path and locate NAV-UGS ► Survey NAV-UGS locations onto course using DGPS  Perform marker vehicle tests over 3 km course ► Collect data from NAV-UGS and INS at prescribed speeds ► Post process data to generate coefficients for path polynomials  Demonstrate precision path following over 3 km course ► Train driver to follow heading and speed commands without reference to horizon ► Drive path using data from INS, NAV-UGS, and NAV algorithm  Compare results to DGPS scoring system to demonstrate follower tracks within + 0.5 m of marker’s path  Perform follower tests using INS + VMS aiding only and compare to INS + VMS + NAV-UGS aiding