Design and Development of a Motorized Mobility Retrofit for a Ballistic-Resistant Podium (MAPS)

Abstract

Ballistic-resistant podiums deployed in public-facing security environments provide effective static protection, but their mass makes them difficult to reposition quickly. This paper presents the Motorized Anti-Ballistic Podium System (MAPS), a motorized, operator-controlled mobility base retrofitted to an existing bullet-resistant podium. The system integrates a 2,000 W brushless DC motor, a 48 V/30 Ah lithium-ion battery pack, an electronic motor controller, a pre-assembled tracked front-axle drive unit, and rear 360° swivel casters, operated through a combined throttle and three-speed-switch interface. The complete unit weighs approximately 1,200 lb and is rated to carry up to 1,800 lb. Functional testing at the UTSA Engineering Senior Design Symposium showed that the platform moved its full rated load unassisted at speeds exceeding 2 mph over grass and rocky terrain, with a measured battery runtime of approximately 30 minutes at full power; steering was functional but difficult. Finite element analysis of the drive shaft under a 1,500 lb load case returned a maximum von Mises stress of 314 MPa against a 310 MPa yield strength for the free-cutting brass shaft material — a safety factor slightly below unity, reported here as a design limitation rather than a validated margin. The work demonstrates a functional proof of concept and identifies drive-shaft strength, maneuverability, and quantitative validation as priorities for future design iterations.