Ford Global Technolgoies, LLC

Ford Motor Company Limited

Fayyaz Saleem

David M Fricke

Rakan C Chabaan

Lawrence Andrew Mianzo

Yuting Rui

Jianhua Zhou

A method and system for controlling an automotive vehicle spindle-coupled road simulator with a predetermined effective road profile for a road surface uses tire loss-of-contact compensation to modify the tracking parameter in a control loop to avoid incorrectly loading a test vehicle. Tire deflection obtained during measurement of a vehicle's tire profile calculation is used to detect and flag regions where the tire profile is not a function of the road input so that the tire profile motion is governed only by the free dynamic response of the suspension. A tire model is first developed for a vehicle. The vehicle is then coupled to the spindle-coupled simulator, and a set of control signals is generated in a control loop. The control signals are used for driving the spindle-coupled simulator with the vehicle attached thereto so that a response generated by the simulator is consistent with the predetermined effective tire profile. Determination of the set of control signals includes selection of a composite tracking response from a generated output representing a tire in contact with the road surface and a tire deflection output representing a tire having lost contact with the road surface.

Effective road profile simulation method and system with tires

A method and system for generating an effective road profile for use with a computer aided vehicle design system is disclosed. The method has the steps of developing a vehicle model for a vehicle is developed and then excited with an initial drive file to produce a vehicle model response. The vehicle model response is compared to a desired response to produce an error signal, the desired response being based on vehicle dynamics data from a vehicle when driven over a road surface. A modified error signal is determined using a vehicle response model, and the modified error signal is fed into the vehicle model to produce a vehicle model response. A new error signal is iteratively determined until it is within a predetermined limit to produce a vehicle model effective road profile. Once the effective road profile has been determined, a modified vehicle model is excited with the effective road profile to produce a modified model response. The modified vehicle can thus be tested without need for a prototype. Various vehicle model parameters are graphically displayed, as are the vehicle model responses, so that a vehicle designer may interactively change the vehicle model or other parameters.

Vehicle road load simulation using effective road profile

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Taylor, MI, United States of America

Fayyaz Saleem