Force control strategies while driving electric powered wheelchairs with isometric and movement-sensing joysticks
Force control strategies while driving electric powered wheelchairs with isometric and movement-sensing joysticks
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DOI：
10.1109/tnsre.2007.891394
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发表时间：
2007-03-01
影响因子：
4.9
通讯作者：
Brown, Karl W.
中科院分区：
文献类型：
--
作者：
Dicianno, Brad E.;Spaeth, Donald M.;Brown, Karl W.
电动轮椅（EPWs）控制接口的创新可以使220 000名当前用户和超过125 000名希望移动但无法使用传统运动传感操纵杆（MSJ）的个人受益。我们开发了一个数字等距操纵杆（IJ）与复杂的信号处理和两个控制功能。在之前的一项研究中，受试者使用我们的IJ的驾驶准确性与使用MSJ相当。然而，我们观察到受试者在IJ上使用过度的力，可能是因为其刚性柱不提供位置反馈。因此，本文研究了在以前的研究中记录的时间序列数据，以表征受试者的力量控制策略，因为弱点是一个问题。十一EPW用户上肢损伤驾驶EPW使用IJ两种不同的控制功能和MSJ在菲茨定律范式。受试者依赖于MSJ的位置反馈，并使用适当的力量。相比之下，使用具有任一控制功能的IJ的受试者施加的力显著高于必要的力（p < 0.0001和p = 0.0058）。使用更高的平均力与更快的试验时间相关，但与准确性无关。缺乏位置反馈可能导致使用过多的等长力。修改控制功能、调整增益或提供额外的训练或反馈可以解决这个问题。
Innovations to control interfaces for electric powered wheelchairs (EPWs) could benefit 220 000 current users and over 125 000 individuals who desire mobility but cannot use a conventional motion sensing joystick (MSJ). We developed a digital isometric joystick (IJ) with sophisticated signal processing and two control functions. In a prior study, subjects' driving accuracy with our IJ was comparable to using an MSJ. However, we observed subjects using excessive force on the IJ possibly because its rigid post provides no positional feedback. Thus, this paper examines the time-series data recorded in the previous study to characterize subjects' force control strategies since weakness is a concern. Eleven EPW users with upper limb impairments drove an EPW using an IJ with two different control functions and an MSJ in a Fitts' law paradigm. Subjects relied upon positional feedback from the MSJ and used appropriate force. In contrast, subjects using the IJ with either control function applied significantly higher force than necessary (p < 0.0001 and p = 0.0058). Using higher average force was correlated with quicker trial times but not associated with accuracy. Lack of positional feedback may result in use of excess isometric force. Modifying control functions, adjusting gain, or providing additional training or feedback might address this problem.