汽车外文翻译---驾驶者的转向感(10)

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force perception and change the feel.

The second experiment determined the differences required in steering-wheel force and angle for the differences to be detected. A difference of 15 percent for force and 14 per cent for angle was required for the difference to be detected 79.4 per cent of the time. Difference thresholds can be described using the theory of signal detection, with no one value for the threshold but values that vary according to the corect response rate. A 'receiver-operating characteristic' (ROC) curve would describe the difference threshold over all response rates. The experiment provided one point on the ROC curve; it would be desirable to measure other points and to construct a full ROC curve so that the relation between the difference threshold and the probability of detecting

a difference can be seen. The conditions in which the difference thresholds were determined may have influenced the thresholds determined. In the present study, subjects 'relaxed' between the force trials and returned the wheel to the centre between the angle trials, representative

of successive presentations of individual stimuli rather than incremental changes in force or angle as will occur during driving. Notwithstanding the limitations of the experiment, the results may be useful in various areas. For example, they provide insight into the differences that may be acceptable from asymmetries in a steering system, and the differences acceptable during repeated turns

The results of the third experiment show that neither the perception of steering wheel force nor the perction of steering wheel angle is 'linear. Understanding of how drivers perceive the feed back of steering-wheel force and steering-wheel angle requires recognition that their feel is not linearly related to either the force or the angle

The studies reported in this paper investigated how the perception of steering-wheel force and steeringwheel angle depend on force and angle respectively. There may be limitations in the application of the findings to vehicle steering systems where the force applied to a steering wheel and the steering wheel-angle vary together. The perception of force or angle may be altered by variations in angle or force respectively. Additionally, auditory, visual and other somatosensory stimuli present in vehicles but not in this laboratory study may affect the perception of force and angle at a steering wheel 5 CONCLUSIONS

Steering-wheel force rather than steering-wheel torque， and steering-wheel angle rather than the translational displacement ofthe hands on the steering wheel, are more efficient descriptors of'steering feel'. When judged in successive presentations, the median difference threshold for the perception of steering-wheel force was found to be 15 per cent and the median difference threshold for the perception of steering-wheel angle was 14 per cent. The rate of grow of sensation of steering-wheel force follows a power law function with an exponent of 1.39; so erceptions of steering force increase more rapidly han