SPAMR: Self-Propelled Amphibious Mine Roller

Row upon row of simple-looking metal capsules are lined up on the deck of a USMC landing craft. One by one, they roll up a ramp and over the side, tumbling into the waves. Sinking to the bottom, each SPAMR rights itself and gets its bearings as its two massive, wraparound wheels begin to propel it across the seabed under command from a central swarm controller. Rolling in formation with its peers to breach a path up the beach, the SPAMR uses its wide wheel diameter to power over obstacles, and it's one and a half tons of weight, borne on its metal finned wheels, to trigger and detonate pressure fuzed mines lying in the sand and muck on the seabed.   The 2-wheeled SPAMR represents a novel approach to the surfzone crawling MCM robot that addresses drawbacks to the 4-wheeled steered and tracked models that are most common in this application. Two-wheeled balance robots were originally introduced to the market with the Segway personal transport device in 2001. They possess two characteristics that give them an edge over other architectures. First, mechanical simplicity: the two-wheeled balancing robot has only two moving parts: the drive wheels. This is the most simple possible mechanism for a fully mobile robot, and this simplicity is hugely beneficial in the marine environment, reducing the number of seals and potential leak areas. Second: increased stability with no requirement for suspension: two-wheeled balancing robots offer enhanced stability over rough terrain, without the requirement for suspension. The system is inherently more controllable despite being under-constrained because active controllers can maintain stability and the geometry of the robot inherently avoids over-constrained scenarios like bumps where a controller becomes underactuated. Numerous research papers have confirmed the ability of these robots to tackle terrain more effectively than three and four-wheeled robots. For the CRAB application, the two wheel robot also has the advantage that the system's entire weight is over the two sole primary wheels, maximizing the pressure the system can apply relative to its total weight. A breaching formation of SPAMRs will cost less to acquire and maintain than the M1157 Assault Breaching Vehicle, and will not put any lives at risk as it does the job. SPAMR Proposed Design Features: 1200lb weight on rollers will trigger pressure fuzed mines, like a mine roller. Wheels make up nearly the entire outer area of the vehicle, maximizing its ability to climb up and over obstacles and making it totally self-righting in all orientations. Non-ferrous construction allows for magnetometer sensing. Electro-hydraulic propulsion system uses inexpensive COTS parts. 2-wheeled concept minimizes moving parts and water seals. Compressed-air buoyancy bladder aids recovery at sea and helps get SPAMR out of sticky mud. Acoustic navigation and C2 for submerged operations. Mesh radio for terrestrial operations. Estimated unit cost $40K-$50K.