Design and Testing of an Active Suspension System for a 2-1/2 Ton Military Truck

The University of Texas Center for Electromechanics (UT-CEM) has been developing active suspension technology for off-road vehicles since 1993. The UT-CEM approach employs fully controlled electromechanical actuators to control vehicle dynamics and passive springs to efficiently support vehicle static weight. The project described in this paper is one of a succession of projects toward the development of effective active suspension systems, primarily for heavy off-road vehicles. Earlier projects targeted the development of suitable electromechanical actuators. Others contributed to effective control electronics and associated software. Another project integrated a complete system including actuators, power electronics and control system onto a HMMWV and was demonstrated at Yuma Proving Grounds in Arizona. Test results, described in previous papers, showed significant reductions in vehicle sprung mass accelerations with simultaneous increases in cross-country speed when compared to conventional passive suspension systems. Additionally, vehicles with EM suspensions have proved to have increased payload capacity and reduced fuel consumption.

The paper presents a brief history and overview of the active suspension program at UT-CEM including the evolution of the actuator design. A description of the vehicle used for this particular demonstration is included along with a discussion of the unique equipment needed to implement an active suspension on a conventionally powered truck. Finally, the paper presents the results of off-road terrain testing for a modified vehicle with active suspension compared to a passively suspended vehicle of the same design. Concluding remarks include performance comparisons, lessons learned and plans for future development and testing.