On the Modeling of Tendon-Driven Systems: a Literature Review

Tendon-driven systems have become popular and efficient solutions for remotely positioning motors and actuation systems in various mechanisms. They address specific needs such as reducing the weight and inertia of moving components and minimizing their dimensions. Tendon-actuated systems offer benefits like low cost and the absence of backlash, leading to significant interest in tendon modeling within the scientific community. This interest spans from analytical solutions with inextensible tendons to computer-aided engineering (CAE) approaches utilizing tendons as deformable elements. However, developing tendon-based actuation systems through CAE tools has been limited due to substantial computational requirements and the challenge of obtaining reliable, technically applicable results. Finite element analysis (FEA) becomes complex and unsuitable for the design phase due to the significant deformation and displacement resulting from tendons’ flexible behavior. Consequently, research into robotic systems actuated by tendons typically relies on analytical calculus and data from costly prototypes, requiring significant time and investment. Moreover, incorporating soft structures makes creating a comprehensive analytical model of the entire system in three-dimensional space daunting or even impossible, particularly with more complex soft structures, thus making FEA analysis the only viable approach. This work reviews the main solutions explored in the literature for solving these systems, aiming to provide designers with a broader view of the possible techniques that can be used based on the specific application.