Testing & Validation THE INFLUENCE OF GROUND COMBAT VEHICLE - - PowerPoint PPT Presentation
Modeling & Simulation, Testing & Validation THE INFLUENCE OF GROUND COMBAT VEHICLE WEIGHT ON AUTOMOTIVE PERFORMANCE, TERRAIN TRAVERSABILITY, COMBAT EFFECTIVENESS, AND OPERATIONAL ENERGY Robert J. Hart, PhD Richard J. Gerth, PhD
8/22/2018
Robert J. Hart, PhD Richard J. Gerth, PhD
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8/22/2018
Overview
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Introduction: Motivation
– The challenge presented from the Lightweight Combat Vehicle Science and Technology Campaign was to create appropriate metrics that would better reflect the performance trade with regards to weight.
– Air and Land Transportability
being transported – Operational Energy
consumption and improves operational energy efficiency – Freedom of Movement
manner in which the system will be delivered to the fight – Combat Effectiveness
the objective
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*Gerth, R. and Howell, R., "What Is a Ton of Weight Worth? A Discussion of Military Ground System Weight Considerations," SAE Technical Paper 2017-01-0270, 2017, doi:10.4271/2017-01-0270.
8/22/2018
Introduction: Scope of Current Study
effectiveness, and operational energy.
– Each simulation was conducted with the vehicles at 100% of their baseline Gross Vehicle Weight (GVW) and at 85% of their GVW for a total of 6 vehicle/weight combinations. – No other vehicle performance characteristics, such as survivability or lethality were altered. – In other words, it was assumed that the weight reduction occurred through implementation of technology that did not
Vehicle Name Weight [% of GVW] 1. M2A3 Bradley Fighting Vehicle 100% 2. M2A3 Bradley Fighting Vehicle 85% 3. M1A2 Main Battle Tank (MBT) 100% 4. M1A2 Main Battle Tank (MBT) 85% 5. M1126 Stryker Infantry Carrier Vehicle (ICV) 100% 6. M1126 Stryker Infantry Carrier Vehicle (ICV) 85%
Vehicles and weight alternatives considered in this study.
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Automotive Performance Analysis: Methods
– Top speed (mph) – The maximum speed the vehicle can move on flat terrain (0% grade). A larger value is better. – Speed on 10% grade (mph) – The maximum speed the vehicle can move on a 10% grade. A larger value is better. – Speed on 60% grade (mph) – The maximum speed the vehicle can move on a 60% grade. A larger value is better. – Dash speed (time to cover 50 meters from a dead stop in seconds) – this is a measure of the vehicle acceleration, similar to a quarter mile measurement in automotive. A smaller value is better. – Fuel economy at a constant 30 mph convoy speed (mpg) – miles per gallon of fuel a vehicle can move. A larger value is
(paved road, secondary road, and cross-country) and measuring their fuel economy. – Vehicle range (miles) – The range of the vehicle. This is proportional to the fuel efficiency. A larger value is better.
– Fuel economy and performance modeling simulations of a vehicle. – GT-Suite models of the M2A3 and M1126 Stryker were developed for the analysis.
– MATLAB script was created and used to calculate the performance of the M1A2.
validating, each vehicle model analysis was conducted at the current GVW as well as at 85% of the current GVW, and the mobility metrics were calculated and recorded.
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Automotive Performance Analysis: Results
– 15% weight reduction led to an improvement in top speed of 8%. Similarly, speed on grade increased by 20% or more, and fuel efficiency improved by 12%.
– Fuel efficiency improved by an impressive 14% across a variety of terrains.
– Significant improvements in speed on grade (10-14%) and fuel efficiency (8%) due to lightweighting.
Vehicle Top Speed (mph) Speed
Grade (mph) Speed
Grade (mph) Dash Speed (Seconds) Fuel Economy (mpg) Range (miles) M1A2
+8.4% +27.4% +19.5%
+12.0% +12.0% M2A3
+0.5% +15.2% +100%
+14.3% +14.3% STRYKER
+0.1% +9.8% +14.2%
+7.8% +7.8%
Automotive Performance Results
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Combat Effectiveness Analysis: Methods
Combat Vignette:
– Blue Force (BLUFOR) consisting of single platoon (4 combat vehicles). The lead vehicle was labeled BLUE1, followed by BLUE2, BLUE3, and BLUE4. – BLUFOR’s mission was to traverse through a village in hostile territory
(Figure (a)). – Heavy Opposition Force (OPFOR) instigated an ambush scenario, which occurred primarily between points 2 and 3 in Figure (b).
OPFOR consisted of two squads, or 4 total anti-tank teams .
to 3 squads, or 6 total anti-tank teams. Map of urban ambush vignette from OneSAF with (a) the full route highlighted in red and (b) a close up view of the urban area and ambush. (a) (b)
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Combat Effectiveness Analysis: Methods
determine if a vehicle was hit, which depended on factors such as:
– Weapon/munition, shot distance, angle, vehicle speed, trajectory of munition, etc.
additional factors such as:
– Munition and target pairing, aspect angle, range, elevation, and dispersion.
i. No Kill (i.e. individual system is still combat effective) ii. Mobility Kill (loss of mobility) iii. Fire Kill (loss of weapons) iv. Mobility + Fire Kill v. Catastrophic Kill (All systems lost – Fire, Mobility, Communications, Sensors, etc.)
– % of simulations where at least 3 vehicles remained combat effective (% CE) – Average number of hits sustained – Time in the kill zone – Average speed in the kill zone – Maximum speed in the kill zone
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Combat Effectiveness Analysis: Results
Mobility-Focused Analysis:
improves combat effectiveness.
– In the OneSAF mobility model, vehicle weight contributes to: (i) acceleration, (ii) ground frictional force, and (iii) weight force due to terrain slope (U.S. Army Materiel Systems Analysis Activity, 2005). – Within the vignette, vehicles remained on road with minimal terrain slope
weight compared to the terrain type and terrain slope.
acceleration through the dash speed metric.
– The 15% weight reduction had similar influence in both models.
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Combat Effectiveness Analysis: Results
– 21.9% improvement in %CE – 13.6% fewer hits sustained – 7.7% less time in kill zone – 7.5% higher average speed in kill zone – 8.6% higher maximum speed in kill zone
– 62.5% improvement in %CE – 17.6% fewer hits sustained – 7.4% less time in kill zone – 8.4% higher average speed in kill zone – 10.0% higher maximum speed in kill zone
– 30.9% improvement in %CE – 13.5% fewer hits sustained – 1.0% less time in kill zone – 0.7% higher average speed in kill zone – 5.3% higher maximum speed in kill zone
Vehicle % CE Avg. Hits Time in Kill Zone [s]
Kill Zone [m/s]
Kill Zone [m/s] M1A2
+21.9%
+7.5% +8.6% M2A3
+62.5%
+8.4% +10.0% Stryker
+30.9%
+0.7% +5.3%
Combat Effectiveness (CE) Results. Note: % CE denotes the percentage
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Combat Effectiveness Analysis: Results
Speed versus distance for lead vehicles along the entire vignette route *Note: 1 m/s = 2.24 mph
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Combat Effectiveness Analysis: Results
*Note: 1 m/s = 2.24 mph Speed versus distance for M1A2 lead vehicle along the route for a zoomed in view of the ambush (kill zone)
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Terrain Traversability Analysis: Methods
– Industry standard tool for predicting vehicle mobility
– primarily foliage and muddy terrain – primarily sandy terrain – primarily mountainous terrain.
– Vehicle Cone Index (VCI) - VCI quantifies the minimum soil strength required for a vehicle to consistently make a specified number of passes (Stevens, et al., 2013). Its proportional to the vehicle’s ground pressure, and a lower VCI typically means better soft soil mobility performance. In this case VCI1 relates to one vehicle pass
– % NoGo - The percentage of the terrain in which the vehicle will not be able to travel. A smaller value is better. – V50 Speed - The average speed the vehicle is able to travel over 50% of the most trafficable terrain. A larger value is better. – V80 Speed - The average speed the vehicle is able to travel over 80% of the most trafficable terrain. A larger value is better.
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Terrain Traversability Analysis: Results
Terrain Type 1: Primarily Foliage and Mud Vehicle Weight % NOGO V50 (mph) V80 (mph) Dry M1A2 100%
5.1% 10.4% 6.7% M2A3 100%
10.7% 10.7% M1126 100%
5.5% 4.5% Wet M1A2 100%
21.0% 16.0% M2A3 100%
21.2% 22.6% M1126 100%
18.0% 0.0% Terrain Type 2: Primarily Sand Vehicle Weight (lb) % NOGO V50 (mph) V80 (mph) Dry M1A2 100%
11.0% 9.0% M2A3 100%
0.0% 6.6% 8.8% M1126 100%
5.4% 3.7% 1.9% Wet M1A2 100%
11.2% 10.4% M2A3 100%
0.0% 9.4% 11.4% M1126 100%
5.1% 6.1% 3.4% Terrain Type 3: Primarily Mountainous Vehicle Weight (lb) % NOGO V50 (mph) V80 (mph) Dry M1A2 100%
13.5% 12.2% M2A3 100%
14.4% 0.0% M1126 100%
12.3% 9.1%
Wet M1A2 100%
14.3% 13.6% M2A3 100%
16.5% 0.0% M1126 100%
5.4% 10.5% 0.0%
– As weight decreased, the VCI1 decreased for all 3 vehicles studied
– In general, the 15% reduction in weight did not improve the % NoGo for the Stryker system (wheeled). For the Bradley and Abrams systems (track), on the other hand, the 15% reduction in weight did generally improve the % NoGo depending
– In general, M1A2 and M2A3 were able to achieve higher maximum speed across all terrain types and soil moisture conditions. For M1126, the data was inconsistent.
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Operational Energy Analysis: Methods
– Discrete-event stochastic simulation toolset designed to model and simulate multi-echelon operations and logistics support activities at a System of Systems level – Key input was fuel economy (from automotive mobility analysis)
– Analyze effect of M1A2 and M2A3 weight within Armored Brigade Combat Team
– Analyze effect of Stryker weight within Stryker Brigade Combat Team (SBCT)
– Gallons of Fuel Used – Number of Fuel Convoy Trucks Required
Effect of 15% Lighter Weight Vehicle on Fuel Usage and Fuel Truck Deliveries
Gallons of Fuel Saved 8,000 gallons over 13 days of operation for M1A2 and M2A3 in ABCT 1,870 gallons over 10 days of
Reduction in Fuel Trucks Deliveries 6 trucks over 13 days of operation for ABCT No Change in Fuel Truck Deliveries over 10 days of
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Brigade Combat Team Relevance
FM 3-90.6: Brigade Combat Team Organization
combined arms units that execute
HBCTs require significant strategic airlift and sealift to deploy and sustain. Their fuel consumption may limit operational reach.”[8]
battalion (CAB) is the HBCTs primary maneuver force. The CAB’s mission is to close with, and destroy or defeat enemy forces within the full spectrum of modern combat operations. A CAB maintains tactical flexibility within restricted terrain.”[8]
Current Study Results
+
Top Speed (+8% for M1A2)
+
Speed on Grade (+10-100% for M1A2, M2A3, M1126)
+
Acceleration (+5-6% dash speed for M1A2, M2A3, M1126)
+
Fuel Economy (+8-14% for M1A2, M2A3, M1126)
+
Lighter weight vehicles could potentially reduce the closure time of transporting a BCT via air.
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Brigade Combat Team Relevance
FM 3-90.6: Offensive Operations
either mounted or by air, provides the BCT commander with the option to position combat power rapidly, this limits the enemy’s ability to react.”[8]
enemy, terrain and weather, troops and support available, time available, and civil considerations (METT- TC) when choosing the combat formation that best balances firepower, tempo, security, and control.”
The type of formation the BCT commander selects is based on: Planned actions on the objective, the likelihood
the terrain the BCT must cross, and the balance of speed, security, and flexibility required during movement.”
determine when, where, and how the BCT transitions into different movement formations based on the terrain and anticipated situation. The commander and all subordinate units also maintain the flexibility to adapt to new formations based on changes in the terrain and enemy situation.”[8]
Current Study Results
+
Top Speed (+8% for M1A2)
+
Speed on Grade (+10-100% for M1A2, M2A3, M1126)
+
Acceleration (-5-6% dash time for M1A2, M2A3, M1126)
+
Fuel Economy (+8-14% for M1A2, M2A3, M1126)
+
Reduction in VCI1 (10-16% reduction)
+
Reduction in % NoGo
+
Improvements in V50 & V80
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Brigade Combat Team Relevance
FM 3-90.6: Defensive Operations
Defending commanders use all available means to disrupt enemy forces. […] Defenders seek to increase their freedom of maneuver while denying it to attackers. Defending commanders use every opportunity to transition to the offense, even if only temporarily. As attackers’ losses increase, they falter and the initiative shifts to the defenders. These situations are favorable for
their decisive point. Surprise and speed enable counterattacking forces to seize the initiative and
to all types of defensive operations (i.e., area, mobile, and retrograde) and focus on several key questions: Where is the key and decisive terrain? How can the BCT use key and decisive terrain to defeat/destroy the enemy?”[8]
Current Study Results
+
Top Speed (+8% for M1A2)
+
Speed on Grade (+10-100% for M1A2, M2A3, M1126)
+
Acceleration (-5-6% dash time for M1A2, M2A3, M1126)
+
Fuel Economy (+8-14% for M1A2, M2A3, M1126)
+
Reduction in VCI1 (10-16% reduction)
+
Reduction in % NoGo
+
Improvements in V50 & V80
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Conclusions
The improvement in mobility (weight) directly resulted in improved combat effectiveness
Impact of 15% weight reduction on mobility, terrain traversability, combat effectiveness, and operational energy metrics. All metrics were studied for M1A2, M2A3, and Stryker, but only the metrics with highest improvements are displayed. Metric M1A2 %Improvement Due to 15% weight reduction M2A3 %Improvement Due to 15% weight reduction M1126 %Improvement Due to 15% weight reduction Mobility Top Speed 8% 1% 0% Speed on 10% Grade 27% 15% 10% Speed on 60% Grade 20% 100%* 14% Dash Speed 5% 6% 5% Fuel Economy (& Range) 12% 14% 8% Terrain Travers. Vehicle Cone Index 1 (VCI1) 15% 16% 10% % NoGo
Sand) 0% (Wet&Dry Sand) to 44% (Dry Mountains)
(Wet Foilage) V (50) 10% (Dry Foliage) to 21% (Wet Foliage) 7% (Dry Sand) to 21% (Wet Foliage) 4% (Dry Sand) to 18% (Wet Foliage) V (80) 7% (Dry Foliage) to 16% (Wet Foliage) 9% (Dry Sand) to 100%* (Wet&Dry Mountains)
(Wet Foliage& Mountains) Combat Effectiveness % of Outcomes Combat Effective 20% 63% 31% Hits Sustained 14% 18% 14% Time in Kill Zone 8% 8% 1% Average Speed in Kill Zone 7% 8% 1% Maximum Speed in Kill Zone 9% 10% 5%
Gallons of Fuel Saved 8,000 gallons over 13 days of operation for M1A2 and M2A3 in ABCT 1,870 gallons over 10 days of
Reduction in Fuel Trucks Deliveries 6 trucks over 13 days of operation for ABCT No Change in Fuel Truck Deliveries over 10 days of