3-DIMENSIONAL MOVEMENT TRAJECTORIES IN FITTS TASK - IMPLICATIONS FOR CONTROL
3-DIMENSIONAL MOVEMENT TRAJECTORIES IN FITTS TASK - IMPLICATIONS FOR CONTROL
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DOI：
10.1080/14640748708401806
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发表时间：
1987-11-01
期刊：
影响因子：
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通讯作者：
EICKMEIER, B
中科院分区：
文献类型：
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作者：
MACKENZIE, CL;MARTENIUK, RG;EICKMEIER, B
根据 Fitts (1954) 的说法，运动时间 (MT) 是运动幅度和目标宽度（难度指数）综合影响的函数。具有相同难度指数的瞄准运动，dMT 可能具有不同的规划和控制过程，具体取决于运动幅度和目标大小的具体组合。对各种幅度和目标尺寸的轨迹进行了评估。三维运动记录系统（WATSMART）在瞄准运动过程中监控手写笔的位置。 MT 结果复制了费茨定律。对合成速度剖面的分析表明了以下显着影响：随着运动幅度的增加，达到合成速度峰值的时间也增加；峰值合成速度随着目标尺寸的增加而略有增加，并且随着运动幅度的增加而增加程度更大；达到峰值合成速度后的时间是振幅和目标尺寸的函数。最终的速度分布在时域中进行归一化，以寻找轨迹形状中的标量关系。这表明： 所得速度分布不对称；峰值速度之前和之后花费的时间比例仅对目标尺寸敏感，即随着目标尺寸减小，曲线变得更加向右倾斜，表明减速阶段更长；对于给定的目标尺寸，可以定义一系列曲线并根据运动幅度进行缩放。这些结果表明，对于给定的目标宽度存在通用程序（基本轨迹表示），并且根据运动幅度进行参数化或缩放。
According to Fitts (1954), movement time (MT) is a function of the combined effects of movement amplitude and target width (index of difficulty). Aiming movements with the same index of difficulty an dMT may have different planning and control processes depending on the specific combination of movement amplitude and target size. Trajectories were evaluated for a broad range of amplitudes and target sizes. A three-dimensional motion recording system (WATSMART) monitored the position of a stylus during aiming movements. MT results replicated Fitts'' Law. Analysis of the resultant velocity profiles indicated the following significant effects: As amplitude of movement increased, so did the time to peak resultant velocity; peak resultant velocity increased slightly with target size, and to a greater extent with increases in the amplitude of movement; the time after peak resultant velocity was a function of both amplitude and target size. Resultant velocity profiles were normalized in the time domain to look for scalar relation in the trajectory shape. This revealed that: the resultant velocity profiles were not symmetrical; the proportion of time spent prior to and after peak speed was sensitive to target size only, i.e. as target size decreased, the profiles became more skewed to the right, indicating a longer decelerative phase; for a given target size, a family of curves might be defined and scaled on movement amplitude . These results suggest that a generalized program (base trajectory representation) exists for a given target width and is parameterized or scaled according to the amplitude of movement.