Non-linear stiffness modeling of multi-link compliant serial manipulator composed of multiple tensegrity segments

TL;DR

This paper develops a non-linear stiffness model for a novel multi-link compliant serial manipulator made of tensegrity segments, analyzing its equilibrium states and buckling behavior using the Virtual Joint Method.

Contribution

It introduces an analytical approach for modeling non-linear stiffness and buckling in a complex tensegrity-based manipulator, validated through simulation.

Findings

The manipulator has six equilibrium configurations, with only two being stable.

The proposed method accurately predicts critical buckling forces.

Simulation results confirm the effectiveness of the analytical technique.

Abstract

The paper focuses on the stiffness modeling of a new type of compliant manipulator and its non-linear behavior while interacting with the environment. The manipulator under study is a serial mechanical structure composed of dualtriangle segments. The main attention is paid to the initial straight configuration which may suddenly change its shape under the loading. It was discovered that under the external loading such manipulator may have six equilibrium configurations but only two of them are stable. In the neighborhood of these configurations, the manipulator behavior was analyzed using the Virtual Joint Method (VJM). This approach allowed us to propose an analytical technique for computing a critical force causing the buckling and evaluate the manipulator shape under the loading. A relevant simulation study confirmed the validity of the developed technique and its advantages in non-linear stiffness analysis.