Dynamic Vehicle

Dynamic Vehicle Vulnerability Underbody Blast Demonstration

By Douglas C. Blankenbiller

Chief, Vehicle Systems Vulnerability Branch, Survivability/Lethality Directorate

Hundreds of underbody/under wheel mine and improvised explosive device (IED) tests have been conducted at ATC since 2007 with the push to rapidly field more survivable vehicles like the Mine Resistant Ambush Protected (MRAP) vehicle. All tests were performed with the vehicles in a static configuration, but in reality, vehicles are typically moving when they are exposed to mine and IED attacks. The static tests have produced valuable data to evaluate system and crew survivability from the initial blast loading, but how the vehicle’s forward momentum contributes to vehicle and occupant responses remains largely unknown. ATC has been actively engaged in addressing this issue through developing its ability to conduct tests and collect data for dynamic vehicle vulnerability test events. To assess progress, the Dynamic Vehicle Vulnerability Demonstration was conducted at C-Field in ATC’s Edgewood area.

The demonstration included one underbody mine event performed on an M1224 MaxxPro MRAP. Featured were the capabilities to remotely drive an armored vehicle downrange along a predetermined course, detonate a mine at a specified location under the moving vehicle, and collect onboard video, crew survivability, and vehicle performance data.

A Pronto4 robotic system was used to drive the unmanned vehicle along a paved road and over a 24-by-24-foot test pit filled with engineered soil compacted to a roadbed configuration. The system provided remote operation of the vehicle’s gear selector, throttle, steering, and braking. Software allowed the remote operator to interface with the system to create a travel path, and path execution was achieved using Global Positioning System (GPS) waypoint following.

A four-laser system and a vehicle-borne reflector were used to provide vehicle location and speed inputs to the Countdown Automation Procedure, Version 3 (CAP III) system that detonated the mine under the vehicle. Each laser was positioned along the center of the paved road at a specified distance from the detonation point. As the vehicle passed over each laser, a signal was sent to the CAP III system. The system verified the vehicle’s course, calculated its speed, and accounted for its location relative to the mine. The system then determined a go/no-go scenario based on the vehicle’s speed and course, and, given a go scenario, armed the system and timed the mine detonation to occur at the proper location under the vehicle.

An integrated networking and power system facilitated the collection of onboard video, crew survivability, and vehicle response data. A Consolidated On-board Interface Network (COIN) mounted inside the vehicle contained the data acquisition and power interfaces for the onboard real-time and high-speed video cameras, accelerometer instrumentation, and crew anthropomorphic test devices (ATDs) with associated Data Acquisition for Anthropomorphic Devices. ATC personnel in the system control room digitally communicated with the instrumentation through the COIN fiber connection and a 1,000-foot fiber tether.

The results of the demonstration validated that ATC now has the capability to conduct underbody testing on vehicles in motion and to collect data throughout the entire event, which includes not only the initial blast loading, but also vehicle flight, subsequent slam-down, and possible rollover. Continued improvements in ATDs and injury criteria will further advance this capability. However, this test was an important step in demonstrating a capability that will allow system survivability to be more completely evaluated, ultimately leading to improved component and system level designs to mitigate the effects of mines and IEDs for enhanced Soldier survivability.