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The use of a fuzzy logic controller for an active suspension system on a wheeled vehicle is investigated. Addressing the opposing goals of ride quality and bump stop avoidance are integrated into one control algorithm. Construction of the fuzzy rules base will be discussed comprehensively along with the membership function setup for both the input and output variables. Numerous quarter-car simulation comparisons will be performed of the fuzzy controller versus the standard skyhook damper controller. The comparisons will include a variety of terrain inputs. Laboratory testing of the fuzzy controller on a single wheel station system is also included.

Battlefield reconnaissance is an integral part of today's integrated battlefield management system. Current reconnaissance technology typically requires land based vehicle systems to observe while stationary or, at best, significantly limits travel speeds while collecting data. By combining current Canadian Light Armored Vehicle based reconnaissance systems with the Center for Electromechanics (CEM) electronically controlled active Electromechanical Suspension System (EMS), opportunities exist to substantially increase cross-country speeds at which useful reconnaissance data may be collected. This report documents a study performed by The University of Texas Center for Electromechanics with funding from L3-ES to use existing modeling and simulation tools to explore potential benefits provided by EMS for reconnaissance on the move.

The University of Texas at Austin Center for Electromechanics (UT-CEM) has been developing advanced suspension technology for high-speed off-road applications since 1993. During the course of the program, advanced simulation techniques, verified by hardware demonstrations, were developed and refined. Based on this experience, UT-CEM conducted a detailed simulation-based comparison of passive, semi-active, and full-active suspension systems for an 18,000 kg (20 ton) 8 x 8 vehicle. Performance metrics are proposed to compare crew comfort, crew effectiveness, on-board equipment effectiveness, and power/energy consumption. This paper presents the methodology and rationale for metrics used in the study, simulation results, and data from this trade study. Results indicate significant advantages offered by well-designed active systems compared to both passive and semi-active, in all metrics.

The University of Texas at Austin Center for Electromechanics (UT-CEM) has conducted a set of simulations and full-scale experiments to determine suitable shock load design requirements for in-hub (wheel) propulsion motors for hybrid and all-electric combat vehicles. The characterization of these design parameters is required due to recent advancements in suspension technology that have made it feasible to greatly increase the tempo of battle. These suspension technologies allow vehicles to traverse off-road terrains with large rms values at greater speeds. As a result, design improvements for survivability of in-hub motors must be considered. Defining the design requirements for the improved survivability of in-hub motors is the driving factor for this research. Both modeling and experimental results demonstrate several realistic scenarios in which wheel hubs experience accelerations greater than 100g, sometimes at very low vehicle speeds.