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The U.S. Army uses the root mean square and power spectral density of elevation to characterize road/terrain (off-road) roughness for durability. This paper describes research aimed toward improving these metrics. The focus is on taking previously developed metrics and applying them to mathematically generated terrains to determine how each metric discerns the relative roughness of the terrains from a vehicle durability perspective. Multiple terrains for each roughness level were evaluated to determine the variability for each terrain rating metric. One method currently under consideration is running a relatively simple, yet vehicle class specific, model over a given terrain and using predicted vehicle response(s) to classify or characterize the terrain.

The U.S. Army uses the root mean square and power spectral density of elevation to characterize road/terrain (off-road) roughness for durability. This paper describes research aimed toward improving these metrics. The focus is on taking previously developed metrics and applying them to mathematically generated terrains to determine how each metric discerns the relative roughness of the terrains from a vehicle durability perspective. Multiple terrains for each roughness level were evaluated to determine the variability for each terrain rating metric. One method currently under consideration is running a relatively simple, yet vehicle class specific, model over a given terrain and using predicted vehicle response(s) to classify or characterize the terrain.

Interactive driving simulation is attractive for a variety of applications, including screening, training and licensing, due to considerations of safety, control and repeatability. However, widespread dissemination of these applications will require modest cost simulator systems. Low cost simulation is possible given the application of PC level technology, which is capable of providing reasonable fidelity in visual, auditory and control feel cuing. This paper describes a PC based simulation with high fidelity vehicle dynamics, which provides an easily programmable visual data base and performance measurement system, and good fidelity auditory and steering torque feel cuing. This simulation has been used in a variety of applications including screening truck drivers for the effects of fatigue, research on real time monitoring for driver drowsiness and measurement of the interference effect of in-vehicle IVHS tasks on driving performance.

Computer simulation and real-time, interactive approaches for analysis, interactive driving simulation, and hardware-in-the-loop testing are finding increasing application in the research and development of advanced automotive concepts, highway design, etc. Vehicle dynamics models serve a variety of purposes in simulation. A model must have sufficient complexity for a given application but should not be overly complicated. In interactive driving simulation, vehicle dynamics models must provide appropriate computation for sensory feedback such as visual, motion, auditory, and proprioceptive cuing. In stability and handling simulations, various modes must be properly represented, including lateral/directional and longitudinal degrees of freedom. Limit performance effects of tire saturation that lead to plow out, spin out, and skidding require adequate tire force response models.

Interactive simulation requires providing appropriate sensory cuing and stimulus/response dynamics to the driver. Sensory feedback can include visual, auditory, motion, and proprioceptive cues. Stimulus/response dynamics involve reactions of the feedback cuing to driver control inputs including steering, throttle and brakes. The stimulus/response dynamics include both simulated vehicle dynamics, and the response dynamics of the simulation hardware including computer processing delays. Typically, simulation realism will increase with sensory fidelity and stimulus/response dynamics that are equivalent to real-world conditions (i.e. without excessive time delay or phase lag). This paper discusses requirements for sensory cuing and stimulus/response dynamics in real-time, interactive driving simulation, and describes a modest fixed-base (i.e. no motion) device designed with these considerations in mind.

An overview is given on design considerations for high-angle-of-attack flying qualities by examining the perspectives of three groups. These groups include the airframe manufacturers, the research community, and the aircraft users. The research community is exploring a diversity of high-angle-of-attack-related topics. Airplane manufacturers are restricted by cost and time constraints in their ability to use the design tools either now available or being developed. The user-pilots dwell upon factors which the manufacturers and researchers alike find difficult to address, such as provision of suitable sensory cues or the pilots' uneasiness with flight control computers. Taken together, the three points of perspective suggest ways in which the design practices and standards for high angle of attack flying qualities might be enhanced.

Results of a study to specify, develop, and test the handling characteristics of a prototype research safety vehicle are reported. Handling requirements which were used to evaluate the transient and steady state response and performance are described. These requirements and criteria were based on a review of contemporary results in the area of handling and controllability, and they combine vehicle performance envelopes and driver-centered considerations. The resulting criteria are used as handling objectives in the testing and evaluation of a prototype small sedan.