A 2-D exoskeleton model with five variable-length links is proposed in the article. The model features not only the active control in the hinges joining separate links, but also the controlled link length alteration. The controlled alteration of the angles between the links in this model is implemented by the drives with reduction gears. The electric drives with rack and pinion gears control the change of the link lengths. Thus, all the degrees of freedom describing the 2-D exoskeleton model are controlled. The electric drives can implement various control algorithms. The method of programmed motion control by specifying information about alteration of kinematic properties describing it is used in this article. Based on this information and the system of differential equations of motion, which is solved algebraically for the control torques and lengthwise forces, their analytical expressions are derived. Thus, the inverse dynamics problem is solved. On the basis of the found control actions, the electric drives have been selected. Electric motors, reduction gears, and rack and pinion gears have been selected from the list of the currently manufactured standard products.
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