# Research on Structural Optimization of High-Sensitivity Torque Sensors for Robotic Joints

## TL;DR

This paper introduces a new sensor design for robotic joints that improves sensitivity and material efficiency through structural optimization techniques.

## Contribution

A novel hourglass-hole spoke-type elastic body and an efficient optimization framework for high-sensitivity torque sensors.

## Key findings

- The optimized sensor achieved 13.1% better material utilization and 11.9% higher sensitivity.
- Baseline sensitivity reached 0.558 mV/N·m, a 19.2% improvement over the dumbbell-hole structure.
- The new design offers a framework for optimizing joint torque sensors using response surface methodology.

## Abstract

To address the urgent need for real-time and high-precision torque perception in robotic manipulators operating in complex environments, this study focuses on the structural optimization design of joint torque sensors. By proposing a novel hourglass-hole spoke-type elastic body structure, a systematic parametric optimization study was conducted with the objectives of improving material utilization and output sensitivity. To enhance optimization efficiency, single-factor experiments and explanatory notes on parameter selection ranges were incorporated to identify factors significantly influencing the target response and to determine their appropriate experimental ranges. Building upon this, the Box–Behnken experimental design method was employed, combined with response surface methodology, to perform multi-objective optimization on the key dimensions of the elastic body. Experimental results demonstrate that the optimized sensor structure achieved a 13.1% improvement in material utilization and an 11.9% increase in sensitivity. The baseline sensitivity of the final sensor reached 0.558 mV/N·m, representing a 19.2% enhancement compared to the optimized dumbbell-hole structure, while material utilization was also improved by 3.1%. This study proposes a novel high-sensitivity hourglass-hole spoke-type elastic body configuration and establishes an efficient response surface optimization framework applicable to the structural design of joint torque sensors fabricated from linear elastic materials, offering new insights for the design and optimization of high-sensitivity torque sensors.