A Test-Based Procedure for the Identification of Rack and Pinion Steering System Parameters for use in CAE Ride-Comfort Simulations

Document Number: 2009-01-2090

Date Published: May 2009

Author(s):
Paola Diglio - LMS International
Jianmin Gu - Ford Motor Co
Greg Falbo - LMS North America

Abstract:
Current CAE modeling and simulation techniques in the time domain allow, by now, very accurate prediction of many ride-comfort performances of the cars. Nevertheless, the prediction of the steering wheel rotation vibration excited by, for instance, wheel unbalance or asymmetric obstacle impact, often runs into the difficulty of modeling the steering line with sufficient accuracy. For a classic rack and pinion, hydraulic-assisted steering line, one of the challenges is to model the complex and nonlinear properties - stiffness, friction and damping - of the rack-rack case system. This paper proposes a rack model, thought for easy implementation in complex multi-body models, and an identification procedure of its parameters, based on measurements, in the operational range of the wheel unbalance excitation. The measurements have been gathered by specific tests on the components and the test setup is also shown here. An example is also presented here of accurate steering wheel rotation vibration predicted by a full-vehicle, multi-body simulation including this rack-rack case properties representation.

File Size: 1035K
Product Status: In Stock

See other papers presented at SAE 2009 Noise and Vibration Conference and Exhibition, May 2009, St. Charles, IL, USA, Session: Body Structure / Chassis (Part 1 of 3)

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