FEEDBACK-REGULATION OF HAND GRASP OPENING AND CONTACT FORCE DURING STIMULATION OF PARALYZED MUSCLE
FEEDBACK-REGULATION OF HAND GRASP OPENING AND CONTACT FORCE DURING STIMULATION OF PARALYZED MUSCLE
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DOI：
10.1109/10.68205
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发表时间：
1991-01-01
影响因子：
4.6
通讯作者：
CHIZECK, HJ
中科院分区：
文献类型：
--
作者：
CRAGO, PE;NAKAI, RJ;CHIZECK, HJ
一个固定参数，离散时间，一阶，反馈控制系统，用于调节在电刺激麻痹的肌肉的手抓。 通过线性组合力和位置反馈信号，抓取的刚度（抓取力和抓取开度之间的关系）保持恒定。 因此，单个连续的命令信号可以在物体获取之前控制抓取开口的尺寸，并且在接触之后控制抓取力和开口。 控制器通过缩放和求和力和位置反馈信号而不是通过控制策略中的离散切换来实现受控变量的这种变化。 在四肢瘫痪的受试者的控制系统的实验测试表明，控制可以获得从空载位置调节等长力调节，以及在这些条件之间的过渡的条件。 控制系统的鲁棒性进行了评估，在力调节与等距负载。 阶跃响应上升时间和超调量更多地取决于系统增益，而不是控制器零点的位置。 响应的上升时间小于两秒，超调小于30%，获得了超过一个增益范围高达10，表明良好的鲁棒性肌肉增益降低，如可能引起的疲劳。
A fixed-parameter, discrete-time, first-order, feedback control system is described for regulating grasp during electrical stimulation of paralyzed muscles of the hand. The stiffness of the grasp (relationship between grasp force and grasp opening) is kept constant by linearly combining force and position feedback signals. Thus, a single continuous command signal can control the size of the grasp opening prior to object acquisition and both grasp force and opening after contact. The controller achieves this change in controlled variables by scaling and summing the force and position feedback signals, rather than by a discrete switch in control strategy. Experimental tests of the control system in quadriplegic subjects show that control can be obtained over conditions ranging from unloaded position regulation to isometric force regulation, as well as in the transition between these conditions. The robustness of the control system was evaluated during force regulation with isometric loads. Step response rise time and overshoot were much more dependent on system gain than on the location of the controller zero. Responses with rise time less than two seconds and overshoot less than 30% were obtained over a gain range up to ten, indicating good robustness to muscle gain reductions such as might be caused by fatigue.