Constrained Motion Planning of A Cable-Driven Soft Robot With Compressible Curvature Modeling

TL;DR

This paper presents a novel motion planning method for cable-driven soft robots that accounts for compressible curvature, enabling effective trajectory tracking and constraint satisfaction such as obstacle avoidance and orientation control.

Contribution

It introduces a compressible curvature kinematics model and formulates the inverse cable actuation as a damped least-squares optimization for constrained motion planning.

Findings

Successful simulation results demonstrating trajectory accuracy

Prototype experiments validating the planning approach

Open-source code for reproducibility

Abstract

A cable-driven soft-bodied robot with redundancy can conduct the trajectory tracking task and in the meanwhile fulfill some extra constraints, such as tracking through an end-effector in designated orientation, or get rid of the evitable manipulator-obstacle collision. Those constraints require rational planning of the robot motion. In this work, we derived the compressible curvature kinematics of a cable-driven soft robot which takes the compressible soft segment into account. The motion planning of the soft robot for a trajectory tracking task in constrained conditions, including fixed orientation end-effector and manipulator-obstacle collision avoidance, has been investigated. The inverse solution of cable actuation was formulated as a damped least-square optimization problem and iteratively computed off-line. The performance of trajectory tracking and the obedience to constraints were evaluated via the simulation we made open-source, as well as the prototype experiments. The method can be generalized to the similar multisegment cable-driven soft robotic systems by customizing the robot parameters for the prior motion planning of the manipulator.