Next-Generation NATO Reference Mobility Model …

1 UNCLASSIFIED: Distribution Statement A. Approved for public release; distribution is unlimited Next-Generation nato Reference Mobility Model (NG-NRMM) Final Report by nato Exploratory Team ET-148 Editors Jean Dasch, Alion Science and Technology, USA Paramsothy Jayakumar, US Army TARDEC, US Authors Michael Bradbury, Defence Science & Technology Laboratory, UK Jean Dasch, Alion Science and Technology, USA Ramon Gonzalez, MIT, USA/Spain Henry Hodges, Nevada Automotive Test Center, USA Abhinandan Jain, Jet Propulsion Laboratory, USA Karl Iagnemma, MIT, USA Michael Letherwood, US Army TARDEC, USA Michael McCullough, BAE, USA Jody Priddy, US Army ERDC, USA Brian Wojtysiak, US Army Materiel Systems Analysis Activity (AMSAA), USA Wong, Vehicle Systems Development Corp., Canada ET-148 Leaders Paramsothy Jayakumar, US Army TARDEC, USA Michael Hoenlinger, Kraus-Maffei Wegmann GmbH&Co, Germany AVT Panel Board Member Sponsor David Gorsich, US Army TARDEC, USA Disclaimer: Reference herein to any specific commercial company, product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or the Department of the Army (DoA).

2 The opinions of the authors expressed herein do not necessarily state or reflect those of the United States Government or the DoA. and shall not be used for advertising or product endorsement purposes. UNCLASSIFIED: Distribution Statement A. Approved for public release; distribution is unlimited Final Report of Exploratory Team, ET-148 next generation nato Reference Mobility Model (NRMM) Development EXECUTIVE SUMMARY The nato Reference Mobility Model (NRMM) is a simulation tool aimed at predicting the capability of a vehicle to move over specified terrain conditions. NRMM was developed and validated by the Army Tank Automotive Research, Development, and Engineering Center (TARDEC) and Engineer Research and Development Center (ERDC) in the 1960s and 70s, and has been revised and updated throughout the years, resulting in the most recent version, NRMM II. NRMM is traditionally used to facilitate comparisons between vehicle design candidates and to assess the Mobility of existing vehicles under specific scenarios.

3 Although NRMM has proven to be of great practical utility to the nato forces, when compared to modern modeling tools it exhibits several inherent limitations. It is based on empirical observations, and therefore extrapolation outside of test conditions is difficult or impossible. It is heavily dependent on in-situ soil measurements. Only two-dimensional analysis is possible; lateral vehicle dynamics are not considered. It does not account for vehicle dynamic effects, but instead only considers steady-state conditions. It is specific to wheeled/tracked vehicles. It is not easily implementable within modern vehicle dynamics simulations. It exhibits poor (or poorly understood) inter-operability and inter-scalability with other terramechanics and soil mechanics models. Exploratory Team 148 was formed to explore the development of a Next-Generation NRMM (NG-NRMM). Theme areas were developed and teams worked on Requirements, Methodology, Tool Choices, and Input/Output needs for a NG-NRMM.

4 Two new areas were also explored that were not part of the original NRMM: stochastics and intelligent vehicles. Based on the results of the exploration of tool choices, a benchmarking exercise was also planned to understand the capabilities of the physics-based tools available from software developers. Through this effort, the goal is to have a Mobility Model with enhanced capabilities in the following areas: Increased flexibility to support operations by assessing the operational Mobility of different deployed platforms in different areas of operation and routes Improved flexibility as a design and procurement support tool through enhanced fidelity and the ability to Model current and emerging Mobility technologies At the conclusion of ET-148, the committee consisting of 38 persons from 13 nations, was confident that the time was right to develop an improved vehicle Mobility Model appropriate to the needs of the nato nations.

5 As laid out in this report, the requirements and methodology necessary for developing a NG-NRMM have been well specified. The follow-on activity, AVT-248, has been approved and will proceed from 2016 to 2018 to develop such a Model . iii TABLE OF CONTENTS EXECUTIVE SUMMARY II TABLE OF CONTENTS III LIST OF ACRONYMS VIII CHAPTER 1 INTRODUCTION 11 BACKGROUND ..11 PURPOSE ..11 ENHANCED CAPABILITIES ..12 REFERENCES ..12 CHAPTER 2 ORGANIZATION 13 ET-148 ORGANIZATION ..13 CHAPTER 3 NRMM HISTORY 14 HISTORY ..14 REFERENCES ..15 CHAPTER 4 NRMM OVERVIEW 17 NRMM METHODOLOGY ..17 PREPROCESSORS (OBSDP and VEHDYN) ..18 INPUT REQUIREMENTS ..20 OUTPUT FORMATS ..21 CHAPTER 5 THEME OVERVIEW 23 CHAPTER 6 THEME 1: REQUIREMENTS 24 GOALS AND DELIVERABLES ..24 UNCLASSIFIED: Distribution Statement A. Approved for public release; distribution is unlimited iv INITIAL SOLICITATION OF IDEAS ..24 THE USER ..27 KEY NEW REQUIREMENTS.

6 28 next STEPS ..30 CHAPTER 7 THEME 2: METHODOLOGY 31 GOALS AND DELIVERABLES ..31 DRAFT NORMMS SPECIFICATION ..35 DETAILED NORMMS COMPLIANCE ASSESSMENT ..35 CHAPTER 8 THEME 3: STOCHASTICS 37 INTRODUCTION ..37 IDENTIFICATION OF NEEDS AND CHALLENGES ..38 RELATED WORK ..38 OVERALL FRAMEWORK OF PROPOSED ARCHITECTURE ..40 POTENTIAL SOLUTIONS TO ELEMENTS OF PROPOSED ARCHITECTURE ..42 PROOF OF CONCEPT RESULTS ..44 RECOMMENDATIONS AND OPEN QUESTIONS ..48 REFERENCES ..48 CHAPTER 9 THEME 4: INTELLIGENT VEHICLES 52 GOALS AND DELIVERABLES ..52 WHAT IS DIFFERENT ABOUT INTELLIGENT VEHICLES? ..53 QUANTITATIVE FRAMEWORK FOR ASSESSING VEHICLE INTELLIGENCE ..57 NRMM(I) PRODUCTS ..62 NRMM(I) PERFORMANCE NRMM(I) METHODS, TOOLS, BENCHMARKING ..65 UNCLASSIFIED: Distribution Statement A. Approved for public release; distribution is unlimited v SUMMARY ..71 REFERENCES ..72 CHAPTER 10 THEME 5: TOOL CHOICES 73 GOALS AND DELIVERABLES.

7 73 TOOL CHOICE DESCRIPTIONS ..73 REQUEST FOR INFORMATION (RFI) ..87 RFI DISTRIBUTION ..91 SCORING ..91 ADDITIONAL QUESTIONS IDENTIFIED DURING AVT MEETING IN POLAND ..111 SUMMARY OF RESULTS ..116 RECOMMENDED next STEPS ..117 CONCLUSIONS ..118 CHAPTER 11 THEME 6: INPUT DATA AND OUTPUT METRICS 121 GOALS AND DELIVERABLES ..121 INPUT DATA / OUTPUT METRIC SUBCOMMITTEE MEMBERSHIP ..121 INPUT DATA / OUTPUT METRIC REFINEMENT APPROACH AND RESULTS ..122 INPUT DATA / OUTPUT POTENTIAL NEAR-TERM STOP-GAP SOLUTIONS ..132 FUTURE WORK / RECOMMENDATIONS ..139 CHAPTER 12 THEME 7: VERIFICATION & VALIDATION 141 GOALS AND DELIVERABLES ..141 OBJECTIVES ..142 QUESTIONS TO BE ADDRESSED ..142 TEST VEHICLES ..144 SOFTWARE DEVELOPERS ..144 TOOL BENCHMARKING V&V SCOPE ..146 UNCLASSIFIED: Distribution Statement A. Approved for public release; distribution is unlimited vi SUFFICIENCY VALIDATION METRICS ..148 SCOPE OF WORK / SCHEDULE (DRAFT).

8 148 CONCLUSIONS ..148 CHAPTER 13 CONCLUSIONS AND RECOMMENDATIONS 150 REQUIREMENTS ..150 METHODOLOGIES ..150 STOCHASTICS ..151 INTELLIGENT VEHICLES ..151 TOOL CHOICES ..151 INPUT DATA AND OUTPUT METRICS ..152 VERIFICATION AND VALIDATION ..152 CHAPTER 14 SUPPORTING MATERIAL 153 APPENDIX A ET-148 TECHNICAL ACTIVITY PROPOSAL (TAP) 154 BACKGROUND AND JUSTIFICATION (RELEVANCE TO nato ): ..154 OBJECTIVE(S): ..155 TOPICS TO BE COVERED: ..155 DELIVERABLE AND/OR END PRODUCT: ..156 TECHNICAL TEAM LEADER AND LEAD NATION: ..156 NATIONS WILLING/INVITED TO PARTICIPATE: ..156 NATIONAL AND/OR nato RESOURCES NEEDED: ..156 RTA RESOURCES NEEDED: ..157 APPENDIX B FINAL REPORT FOLLOWING ET-148 MEETING IN BELGIUM 158 APPENDIX C INITIAL TEAM SURVEY 162 WHAT ARE THE THINGS THAT YOU LIKE ABOUT NRMM? ..162 UNCLASSIFIED: Distribution Statement A. Approved for public release; distribution is unlimited vii WHAT ARE THE THINGS THAT YOU DISLIKE ABOUT NRMM?

9 163 WHAT ARE YOUR REQUIREMENTS FOR THE Next-Generation NRMM? ..167 APPENDIX D THEME 2, NORMMS DETAILED METHODOLOGY 172 APPENDIX E REQUEST FOR INFORMATION (THEME 5) 175 LETTER INTRODUCING REQUEST FOR INFORMATION ..175 INTRODUCTION ..177 HISTORY ..178 GROUND VEHICLE Mobility SIMULATION ENVIRONMENT ..179 SIMULATION STRUCTURE ..181 COMBINATORIAL TRADE STUDY ..183 USER ENVIRONMENT AND SUPPORT ..184 CONTROL ALGORITHMS ..188 VEHICLE-TERRAIN INTERFACE ..188 TERRAIN REPRESENTATION ..189 RESPONSE ..191 APPENDIX F THEME 5 RECOMMENDATIONS FOR A VALIDATION EFFORT 211 UNCLASSIFIED: Distribution Statement A. Approved for public release; distribution is unlimited viii LIST OF ACRONYMS AASHTO American Association of State Highway and Transportation Officials ABM Automatic Brake Modulator ABS Anti-lock Braking System AMC Army Materiel Command ANCF Absolute Nodal Coordinate Formulation AOPM AMSAA Optimal Path Model APC Armored Personnel Carrier API Application Program Interface ARL Army Research Laboratory ASME American Society of Mechanical Engineers AVT Applied Vehicle Technology AWD All Wheel Drive BRDF Bidirectional Reflectance Distribution C2 Command and Control CAE Computer Aided Engineering CFD Computational Fluid Dynamics CG Center of Gravity CGS Coarse Grained Soil CI Cone Index COTS Commercial Off-the-Shelf CRREL Cold Regions Research and Engineering Laboratory CSO nato Collaboration Support Office CTIS Central Tire Inflation System CTS Combinatorial Trade Study CVT Continuously Variable Transmission DEM Discrete Element Method DEM Digital Elevation Model DIL Driver in the Loop DP

10 Drawbar Pull Force DOE Design of Experiments DTED Digital Terrain Elevation Data DTM Digital Terrain Model DVI Digital Visual Interface ERDC Engineer Research and Development Center ESC Electronic Stability Control ET Exploratory Team FEM Finite Element Model FGS Fine Grained Soil UNCLASSIFIED: Distribution Statement A. Approved for public release; distribution is unlimited ix FFT Fast Fourier Transform FMI Functional Mock-up Interface GIS Geographical Information System GOTS Government Off-the-Shelf GP Gaussian Process GPGPU General Purpose Graphics Processing Unit GUI Graphical User Interface GVW Gross Vehicle Weight HGTM High-Resolution Ground Vehicle and Terrain Mechanics HIL Hardware in the Loop HITL Hardware in the Loop HPC High-Performance Computing IMU Inertial Measurement Unit ISO International Organization for Standardization ISTVS International Society for Terrain-Vehicle Systems IVT Infinitely Variable Transmission LIDAR Laser Imaging Detection and Ranging M&S Modeling and Simulation MBD Multibody Dynamics MGRS Military Grid Reference System MMP Mean Maximum Pressure MOE Measures of Effectiveness MOP Measures of Performance MSIE Modeling & Simulation Integrating Environment nato North American Treaty Organization NG-NRMM next generation nato Reference Mobility Model NORMMS nato