Brace for variability in tool positioning: Modeling and simulation of 1 DoF needle insertion task under tool-braced condition

Erroneous human arm motion leads to inaccuracy in tool positioning which often affects the quality of many precision manipulation tasks. Variability in tool endpoints during mechanical interactions among humans, tools, and environments can be reduced by bracing strategies; therefore, such a cost-effective approach may increase accuracy and reproducibility in human arm movements and thus prove useful in improving performance of selected interactive tasks. Although a great number of works is found in the literature related to performance augmentation of braced robotic manipulators, only a few studies are found on bracing strategies for performing interactive tasks and on analogies to human manipulation. In this paper, a method for predicting bracing properties is proposed for single degree of freedom interactive task to improve performance. To reflect real workplace scenarios, models of the human impedance, the brace, and the contact of the interaction are represented and used to predict the quality of the executed task. The task execution model intended to predict real-life performance in both free arm and braced conditions are then used to estimate the brace properties to augment performance of the representative task.