Improving vibration-induced discomfort often requires a reduction in the vibration experienced by vehicle occupants. Simulation software and test equipment are able to measure changes in vibration that are too small for humans to perceive. It is therefore important to know how large the change in vibration should be, i.e. the difference threshold, for occupants to perceive an improvement in comfort. This study estimates difference thresholds for ten automotive engineers seated in a vehicle on a 4-poster test rig. Participants were exposed to multi-axis vibration. Component ride values were calculated by applying BS 6841 frequency weightings and multiplication factors to seat accelerations in the six directions. Difference thresholds were estimated for two road profiles using the vertical component ride value and combined point ride value (i.e. the root-sums-of-squares of the six component ride values). The two road profiles had different magnitudes, but the same spectral shape, resulting in median vertical component ride values of 0.58 and 1.01 m.s.⁻², root-mean-square. An up-down transformed response rule was used with a three-down-one-up response grouping to estimate difference thresholds at a 79.4% probability level. The median relative difference threshold for the two roads was 10.13% and 8.58% considering the vertical component ride value, and 10.99% and 9.24% considering the combined point ride value. No statistically significant difference was found between the medians of the relative difference threshold over the two roads considering either of the two ride values (p-value = 0.995 in both instances), suggesting that Weber's law holds.

改善振动引起的不适通常需要减少乘员的振动。仿真软件和测试设备能够测量对于人类来说太小的振动变化。因此，重要的是要知道振动变化应该有多大，即差异阈值，以使乘员感觉到舒适度的提高。这项研究估算了坐在4杆试验台上的十名汽车工程师的差异阈值。参与者受到多轴振动的影响。通过将BS 6841频率加权和乘数应用于六个方向上的座椅加速度来计算组件行驶值。使用垂直分量行驶值和组合点行驶值（即，六个分量乘积值的平方根和）。两条道路轮廓的幅度不同，但频谱形状相同，导致垂直分量中间行驶值分别为0.58和1.01 ms⁻²，均方根。上下转换响应规则与三级向下一对一响应分组一起使用，以79.4％的概率水平估计差异阈值。考虑到垂直分量行驶值，两条道路的中位数相对差异阈值分别为10.13％和8.58％，考虑到组合点行驶值，则为10.99％和9.24％。考虑到两个行驶值中的任何一个（在两种情况下，p值= 0.995），在两条道路上的相对差异阈值的中位数之间没有发现统计学上的显着差异，这表明韦伯定律成立。