3D Printed Low-Cost Force-Torque Sensors

Abstract

Force sensing is essential for many manipulation tasks and, more generally, for all robots physically interacting with their environment. While multi-axis force/torque sensors are readily available commercially, their cost and complex integration have so far limited a wide deployment. In this paper, we introduce a modular approach to design and to integrate low-cost force sensors directly into 3D printed robot parts. Based on off-the-shelf optical sensors embedded into deformable structures, sensitivity and load capacity can be selected from a wide range. A working six-axis sensor, including electronics, can be built for less than 20 dollars, plus a few hours of 3D printing. We present tested example designs for sensors of different complexity, from a basic one-dimensional deflecting beam to six-axis sensors with custom shapes. We summarize the basic sensor layout geometries, explain key 3D printing and integration aspects, discuss sensor calibration, and describe our Arduino firmware and ROS-based drivers.

The GummiArm Project: A Replicable and Variable-Stiffness Robot Arm for Experiments on Embodied AI

“…Furthermore, the Dynamixel servos provide a relatively slow and inaccurate reading of the load on the servo, which makes estimating forces and torques difficult to do in real-time. Further work on integrating force sensors, such as the ones made available from Hendrich et al ( 2020 ), into the tendons themselves, or the pulley structure, could enable more advanced approaches for controlling the compliance during physical interaction with the environment. While the GummiArm was inspired by the rigid links of the human arm, approaches for making also the links non-rigid and variable-stiffness (see for example Mena et al, 2020 ) may be of interest for future iterations of the arm.…”

Overload Clutch With Integrated Torque Sensing and Decoupling Detection for Collision Tolerant Hybrid High-Speed Industrial Cobots

“…Multiple joint torque sensor technologies exist. The most common ones rely on strain gauges as in [3] and [15] or capacitive sensing as in [16]- [18]. Strain gauge sensor technology is mature but not cheap.…”

Design and analysis of a miniature self-decoupling six-dimensional force/moment sensor

“…For the existing flexible robots applied in complex and narrow spaces, their outer diameter size is often less than 10 mm, and it is difficult for existing sensors to meet the dual requirements of compact size and multi-dimensional measurement at the same time. 6 At present, the multi-dimensional force/moment sensor that is commonly used in the field of intelligent robots has been widely studied by the academe 1 Academy for Engineering & Technology, Fudan University, Shanghai, China 2 because of its characteristics of diverse configurations, 7,8 compact structure, [9][10][11] and easy operation. [12][13][14] In recent years, the research on multi-dimensional force sensors has mainly focused on the design of elastomer configuration, optimization of perceptual force principle, and multi-dimensional force feedback decoupling algorithms.…”