Static Model of Nimbl’Bot Robot

Abstract Industrial manipulators traditionally exhibit lower stiffness than computer numerical control (CNC) machines but offer advantages in machining tasks due to their extensive workspaces and operational efficiency. To address the limitations of conventional industrial robots in such applications, Nimbl’Bot (NB) serial robots were developed, integrating innovative actuation systems that uniquely combine flexibility and stiffness. While these advancements enable NB robots to meet the demands of complex machining tasks, their redundant design and large number of degrees of freedom pose significant control challenges. This work aims to enhance the control of the NB robot by deriving the static model. Initially, a static model for a single NB-module is developed using the Newton-Euler (NE) method. This model is then generalized to represent a NB robot with multiple NB-modules, for this work it is consisting of four modules. In parallel, the robot is modeled and simulated in MuJoCo (Multi-Joint Dynamics with Contact) to validate the analytic static model. The results demonstrate that the derived model accurately predicts the motor torques required to counteract gravity, aligning closely with MuJoCo simulations across various robot configurations, thereby paving the way for improved control strategies.