Multiple-bump roadholding test: Description and metric interpretation

Abstract

Road vehicle roadholding comprehends directional response to road inputs. This response is primarily a function of the roadway's frequency content and amplitude and the vehicle's inertial, suspension and tyre characteristics. There is also evidence that suspension kinematic and compliance steer properties can have a significant contribution (Rill, G. Steady state cornering on uneven roadways. SAE paper 860575, 1986). The multiple-bump roadholding test measures vehicle response to a periodic bump of varying frequency while cornering. By driving a vehicle at different speeds over a set of periodic bumps placed on circles of different diameters, it is possible to observe the response to different fundamental bump excitation frequencies at a particular lateral acceleration. This paper describes the test procedure, measured vehicle responses and the metrics calculated.

Keywords

test procedure chatter bumps heading angle error suspension steer road disturbance response road profiles roadholding dampers damping wheelhop frequency tyre properties

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References

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