Shape Control of Compliant, Articulated Meshes: Towards Modular Active-Cell Robots (MACROs)

In this letter, we explore the shape control of compliant, articulated meshes created from shape memory alloy (SMA)-based linear actuators (Active Cells). These compliant meshes form the mechanical subsystem of a class of proposed modular active-cell robots (MACROs). Our "Active Cells" are centimeter-scale SMA actuators capable of ~25% linear strain. The deformation of MACRO meshes in response to current inputs at the passive nodes are modeled and validated for accuracy in prior work. In this letter, we investigate an efficient and scalable control policy that allows us a given MACRO to be electrically-driven to achieve a specified shape. Validation experiments on a range of MACRO simulations establish a high degree of accuracy and repeatability of the controller. The control strategy is shown to be efficient and robust to variations in start- and target-shapes, and in mesh complexity.