CN-122016135-A - Twelve-beam six-dimensional force sensor

CN122016135ACN 122016135 ACN122016135 ACN 122016135ACN-122016135-A

Abstract

The invention discloses a twelve-beam six-dimensional force sensor, and relates to the technical field of force sensing. According to the sensor, through optimizing the structural design of the elastic body, innovating the bridge mode of the strain gauge group and positioning of the accurate patch, the problem of coupling interference in six-dimensional force measurement is effectively solved, and the measurement accuracy and stability are improved. The sensor adopts a twelve-beam elastomer structure, utilizes COMSOL finite element simulation software to analyze stress distribution under different loads to determine the position of a strain sensitive area, designs a bridge circuit by the tension-compression strain characteristics of symmetrical strain beams, realizes decoupling from a hardware level, selects MEMS silicon strain gauge and accurately assembles, and further reduces measurement errors. Experimental data shows that the crosstalk rate of the sensor under the load of each dimension is as low as 2%, the net output signal is stable, and the sensor can be widely applied to the fields with high requirements on force measurement accuracy, such as robots, precision manufacturing, aerospace and the like.

Inventors

CHEN JUNJIE
CHU GUOFU
LI JIAXIN
HUANG YU
Zhan Jiaorong

Assignees

深圳安培龙科技股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260413

Claims (8)

1. The utility model provides a twelve-beam six-dimensional force transducer, includes elastomer, center loading platform (3) and strain gauge, its characterized in that: The center loading table (3) is provided with a positioning hole (1); The elastic body comprises an outer frame, a central loading table (3) and twelve elastic beams connected between the outer frame and the central loading table, wherein the twelve elastic beams comprise four T-shaped main beams (2) and eight L-shaped auxiliary beams (4), the four T-shaped main beams (2) are uniformly distributed along the circumferential direction of the central loading table (3), and the L-shaped auxiliary beams (4) are symmetrically distributed on two sides of each T-shaped main beam (2); The strain gauge is adhered to a strain sensitive area of the elastic beam, wherein the strain sensitive area is an area with the largest strain under the load of a specific dimension, and the area is determined through finite element simulation analysis; The strain gauges are connected to form a measuring bridge, and the bridge combination mode is to divide the strain gauges on symmetrical strain beams which generate equal and opposite strains in the specific direction, into two groups, and the two groups are respectively connected to adjacent bridge arms of the measuring bridge.
2. Twelve Liang Liuwei force sensor according to claim 1, characterized in that the central loading table (3) is provided with a threaded hole through which external loads are transferred to the elastomer.
3. Twelve Liang Liuwei force sensor according to claim 1, characterized in that the central loading table (3) is of cuboid construction.
4. The twelve Liang Liuwei force sensor as claimed in claim 1, wherein the T-shaped main beam (2) has a rectangular cross section and the L-shaped secondary beam (4) has an L-shaped cross section.
5. The twelve Liang Liuwei force sensor of claim 1, wherein the strain gauge is a MEMS silicon strain gauge.
6. The twelve Liang Liuwei force sensor as in claim 1 wherein 24 strain gages are attached to the elastomer, 4 strain gages for each dimension load, forming a six Wheatstone full bridge circuit.
7. The twelve Liang Liuwei force sensor of claim 1, wherein the finite element simulation analysis is to plot a stress path and select a maximum strain region when the elastomer is subjected to Fx, fz, my, mz load.
8. The twelve Liang Liuwei force sensor of claim 5, wherein the MEMS silicon strain gauge is 1.3mm by 0.15mm in size.

Description

Twelve-beam six-dimensional force sensor Technical Field The invention belongs to the technical field of force sensing, and particularly relates to a twelve-beam six-dimensional force sensor. Background The six-dimensional force sensor is a device capable of simultaneously measuring three force components (Fx, fy, fz) and three moment components (Mx, my, mz) of an object in a three-dimensional space, and is the sensor type with the highest dimensionality and the most comprehensive function in the current force sense sensing field. The six-dimensional force sensor can provide comprehensive force control information, and has an irreplaceable effect in the fields with extremely high force control precision requirements, such as industrial robot precise assembly, medical operation equipment, aerospace test, humanoid robot balance control and the like. However, the conventional six-dimensional force sensor still faces a series of key technical challenges in practical application, and the measurement accuracy and reliability of the conventional six-dimensional force sensor are severely limited. Mainly expressed in the following aspects: 1. Inter-dimensional coupling interference is serious in that due to the nonlinear mechanical characteristics of the six-dimensional force sensor, when one dimension is loaded, other dimensions often generate an unnecessary output signal, and the phenomenon is called inter-dimensional coupling or crosstalk. The ideal six-dimensional force sensor requires independent output in each dimension, but in practice, coupling is difficult to avoid due to factors such as elastomer structural design, strain gauge sticking deviation and the like. In the conventional structural design, the strain sensitive areas are not distributed uniquely, so that a single-dimension load can induce strain in a plurality of areas, and interference components in other dimensions are mixed in an output signal. Although partial design attempts to perform software decoupling through complex algorithms, the methods have large calculation amount and poor real-time performance, rely on a high-performance processing unit, and are difficult to meet the requirements of high-dynamic scenes. 2. The strain gauge is used as a core sensitive element of the sensor, and the pasting position of the strain gauge directly determines the sensitivity and accuracy of signal acquisition. Strain gage attachment of conventional sensors relies heavily on empirical or simplified theoretical analysis, lacking guidance based on accurate stress simulation positioning, resulting in failure of the strain gage to cover the maximum strain area of the elastomer. In addition, the traditional metal foil strain gauge has larger size, is difficult to meet the miniaturization design requirement, has poor temperature stability, is easily influenced by factors such as temperature drift and creep, and further reduces the reliability of signals. 3. The dynamic performance and overload protection are insufficient, and in practical application, the six-dimensional force sensor is often required to deal with high-speed time-varying signals (such as robot polishing, operation force feedback and the like), so that extremely high requirements are put on the dynamic response characteristics of the sensor. While conventional sensors have focused on static performance optimization, research into dynamic performance has been relatively weak, resulting in insufficient signal tracking capability under rapidly changing loads. Meanwhile, the mechanical overload protection structure is complex in design, and the precision and compactness are difficult to be considered while the sensor is comprehensively protected. 4. The calibration process is complex, the cost is high, and the parameter mapping relation required by the decoupling algorithm is obtained through multi-dimensional composite loading by means of special six-dimensional combined loading equipment for calibrating the six-dimensional force sensor. Most of the equipment is manufactured in a non-calibration mode, the cost is high, and the calibration process is easily influenced by the nonlinear characteristic of the inter-dimensional coupling, so that the calibration precision is difficult to guarantee. In addition, the existing sensor lacks systematic compensation for temperature, creep and other error factors, so that the accuracy and stability in long-term use are reduced. In summary, the existing six-dimensional force sensor has significant shortcomings in structural design, signal decoupling, dynamic response, calibration precision and the like, and is particularly difficult to meet the requirements of high-precision force control scenes such as precise operation of robots, medical operations and the like. Therefore, there is a need for a sensor design that can be systematically innovated from multiple aspects such as elastomer structure, patch positioning, bridge assembly, etc., to fundamentally reduce i