Modeling of continuum robots with environmental constraints

Leveraging the intrinsic compliance of continuum robots is a promising approach to enable symbiosis and harmoniousness in an unstructured environment. This compliance in interaction reduces the risk of damage for both the robot and its surroundings. However, the high degrees of freedom of continuum robots complicates the establishment of an analytical model that accurately describes the robot mechanical behavior, particularly in the case of large deformations during contact with obstacles. In this study, a novel modeling method is explored and the configuration space parameters of a robot are defined by considering the environmental constraints and variable curvature. A 10-section continuum robot prototype with a length of 1 m, was developed to validate the model. The robot's ability to reach the target points, to follow complex paths and incidents of contacting with obstacles validate the feasibility and accuracy of the model. The ratio of the robot endpoint average position errors to its length are 2.045% and 2.446%, respectively, in conditions without and with obstacle. Thus, this work may serve as a reference for designing and analyzing continuum robots, providing a new perspective on the integration of robots with the environment.