The effect of vibrational energy distribution on the level of driver detection

A laboratory-based experiment was conducted to investigate the effect of vibrational energy distribution on human cognitive detection of road surface based on steering wheel vibration. The test stimuli used in the current study were ten steering wheel acceleration time histories of mid-sized European automobiles. The ten original steering wheel time histories were manipulated via digital Butterworth filters to eliminate four different frequency bands from the steering wheel vibration spectrum of within 20 to 60 Hz. The ensemble, composed of both the original and the manipulated time histories, was used to perform a laboratory-based detection. During the test, participants were asked to judge if the actuated acceleration stimulus transmitted came from the road surface shown on photographs featured on a board directly in front of the test bench and rate the confidence of their judgement on a five-point scale ((1) = very sure there was no signal – (5) = very sure there was a signal)). The findings suggested that the elimination of vibrational energy in the frequency band of 26.32 Hz to 34.64 Hz can be highly detrimental to human cognitive detection of road surface types. The findings also demonstrate that the frequency band of 26.32 to 34.64 compromises steering wheel feedback the most, and that the elimination of these frequency bands can lead to the correct detection of road surfaces. These relationships may be partly explained by the fact that the elimination of this frequency band appeared to produce the highest peaks of vibrational energy resulting from the resonance in the vehicle’s dynamic systems such as tyres and steering wheel.