Strain Analysis of Six-Axis Force/Torque Sensors Based on Analytical Method

In this study, a novel six-axis force/moment (F/M) sensor was developed. The sensor has a novel ring structure comprising a cross-beam elastic body with sliding and rotating mechanisms to achieve complete decoupling. The unique sliding and rotating mechanisms can reduce cross-talk effects caused by minimized structural interconnection. The forces Fx, Fy, and Fz and moments Mx, My, and Mz can be measured for the six-axis F/M sensors according to the elastic deformation of strain gauges attached to the cross beam. Herein, we provide detailed descriptions of the mathematical models, model idealizations, model creation, and the mechanical decoupling principle. The paper also presents a theoretical analysis of the strain based on Timoshenko beam theory and the subsequent validation of the analysis results through a comparison of the results with those obtained from a numerical analysis conducted using finite element analysis simulations. The sensor was subjected to experimental testing to obtain the maximum cross-talk errors along the following six axes under different loadings (the errors are presented in parentheses): Fx under SMy (2.12%), Fy under SMx (1.88%), Fz under SMz (2.02%), Mx under SFz (1.15%), My under SFx (1.80%), and Mz under SFx (2.63%). The proposed sensor demonstrated a considerably improved cross-talk error performance compared with existing force sensors.

Section: Strain Gauge Arrangementsmentioning

confidence: 99%

Section: Optimizationmentioning

confidence: 99%

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Novel Mechanically Fully Decoupled Six-Axis Force-Moment Sensor

Lin

Ahmad

Kebede

2020

“…Some commercial shaft torque sensors, which measure strain exposed at 45 • and 135 • to the cylinder neutral-axis with a torsional deformation mode, have been specially used in laboratory testing for a long time [1][2][3][4][5]. Many disk torque sensors developed into spoke-type structures, instead, expose strain on the transverse or lateral spoke-surface with a bending deformation mode [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. Recently, owing to axial thinness and low sensitivity to non-torsional components, they have been extensively integrated in robotic joints, wheel driving and intelligent products.…”

Section: Introductionmentioning

confidence: 99%

A Lever-Type Method of Strain Exposure for Disk F-Shaped Torque Sensor Design

Shu

Chu

Shu

2020

Disk-shaped torque sensors are widely used in robotic joints and wheel driving. However, in terms of conventional spoke-type geometries, there is always a trade-off between sensitivity and stiffness, because their strain exposure depends upon a bending deformation mode which causes strain nonuniformity. This paper presents a lever-type method of strain exposure that performs a uniaxial tension and compression deformation mode to optimize the strain uniformity and improve the trade-off. Moreover, on the basis of this approach, the proposed disk F-shaped torque sensor enjoys has axial thinness, easy installation of strain gauges and flexible customization. The simulation and experimental results have validated the basic design idea.

“…The commonly used cross-beam elastomer structure of six-axis wrist force sensor which belongs to plane beam type has the characteristics of small volume, symmetrical, and uncoupled output and integrated processing [ 16 ]. So, the cross-beam six-axis wrist force sensor with a floating beam is widely applied in various tasks for robots, and many scholars have been optimizing it [ 8 , 17 , 18 ] and improving its structure [ 10 , 19 ]. Therefore, the elastomer structure of the six-axis force sensor with floating beam and cross-beams [ 20 ] was analyzed in this paper.…”

Section: Introductionmentioning

confidence: 99%

Design of a Novel Six-Axis Wrist Force Sensor

Wang

et al. 2018

A novel elastic body design idea of six-axis wrist force sensor with a floating beam was raised based on the analysis of the robot six-axis wrist force sensor with a floating beam. The design ideas improve the sensor’s dynamic performance significantly, while not reducing its sensitivity. First, the design ideas were described in detail, which were analyzed by mechanical modeling and were verified by finite element analysis. Second, the static simulation analysis of the novel elastomer of sensor was carried out. According to the strain distribution performance, the position of the strain gauges pasted and the connection mode of the full-bridge circuits were decided, which can achieve theoretical decoupling. Finally, the comparison between the static and dynamic performance of the novel sensor and the original sensor with floating beams was done. The results show that the static and dynamic performance of the novel six-axis wrist sensor are all better than the original sensor.