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CN-122016133-A - Six-dimensional force elastomer with structural decoupling capability and force sensor

CN122016133ACN 122016133 ACN122016133 ACN 122016133ACN-122016133-A

Abstract

The invention provides a six-dimensional force elastomer with structural decoupling capacity, which relates to a force sensor, and comprises an inner mounting block, an outer mounting ring and a composite elastic beam, wherein the inner mounting block and the outer mounting ring are coaxially arranged, the composite elastic beam is matched with the structural shape of the composite elastic beam, the arrangement positions of strain gauges and the connection relation of the strain gauges in a full bridge, the strain gauges of FX and FY are arranged in a high strain area above the surface stress mean value of the composite elastic beam when the elastomer bears single load in the FX direction or the FY direction, so that when the elastomer bears single load in the target direction, the strain distribution of the strain gauge of a target channel enables the full bridge output of the elastomer to meet the formula of Vout (VinxGF/4) x (epsilon 2 +ε 3 - ε 1 -ε 4 ), the absolute value of the combined term is sufficiently large, the strain distribution of the strain gauge of the non-target channel strain gauge enables the full bridge output of the elastomer to be sufficiently miniaturized due to low strain isolation or bridge self-balancing mechanism, high-precision decoupling measurement of hardware level is realized, inter-dimensional coupling interference is effectively inhibited, and coupling error is reduced.

Inventors

  • HAN FANGFANG

Assignees

  • 核桃智能科技（常州）有限公司

Dates

Publication Date
20260512
Application Date
20260204

Claims (10)

  1. 1. Six-dimensional force elastomer that possesses structure decoupling capability, its characterized in that includes the interior installation piece of coaxial setting, outer collar and connects the multiunit composite elastic beam of both, wherein: the composite elastic beam is provided with at least 6 groups of 24 strain gauges, wherein six groups of the strain gauges are respectively used for measuring forces in FX, FY and FZ directions and moments in MX, MY and MZ directions, each group of the strain gauges are electrically connected according to a corresponding Wheatstone full bridge circuit topology to form six independent measuring bridges, and tension and compression polarities of the strain gauges in each group are defined according to the strain directions of the strain gauges under corresponding forward loads and correspond to bridge arm positions in the circuit topology; The structural shape of the composite elastic beam, the arrangement position of the strain gauge and the connection relation of the strain gauge in the full bridge are matched, so that when the elastic body bears load in a single target direction, the strain distribution of the target channel strain gauge enables the full bridge output of the elastic body to meet the formula of Vout (VinxGF/4) x (epsilon 2 +ε 3 - ε 1 -ε 4 ), the absolute value of the combination term is sufficiently large, and the strain distribution of the non-target channel strain gauge enables the full bridge output of the elastic body to be sufficiently minimized due to low strain isolation or bridge self-balancing mechanism; wherein, the bridge self-balancing mechanism means that the strain distribution of the non-target channel meets epsilon < 2+ > epsilon < 3+ > epsilon < 1+ > epsilon < 4 >, so that the output of the bridge self-balancing mechanism approaches zero, and the coupling error is less than or equal to 5%; Wherein Vout represents the output voltage of the Wheatstone full-bridge circuit, vin represents the excitation voltage of the Wheatstone full-bridge circuit, GF represents the sensitivity coefficient of the strain gauge, and ε 1 、 ε 2 、 ε 3 、 ε 4 respectively represents the strain value generated by each group of four strain gauges when being stressed.
  2. 2. The six-dimensional force elastomer with structural decoupling capability of claim 1, wherein the composite elastic beam comprises four vertically distributed elastic beams and eight bumper beams, wherein: the ends of the eight buffer beams are fixedly connected with the inner wall of the outer mounting ring to form a regular octagonal frame, and the opposite ends of the elastic beams are respectively and fixedly connected with the inner mounting blocks and the corresponding ends of the buffer beams; or four buffer beams are fixedly connected to form a regular quadrilateral frame, the other four buffer beams are fixedly connected with the end angles of the regular quadrilateral frame and the end angles of the inner mounting blocks, and the opposite ends of the elastic beams are respectively fixed with the outer mounting rings and the middle parts of the corresponding side edges of the regular quadrilateral frame; all elastic beams and the buffer beams are distributed in a central symmetry manner relative to the central axis of the elastic body and in an axisymmetric manner relative to at least two orthogonal axes passing through the center of the elastic body; six groups of strain gauges are distributed at corresponding positions of the elastic beam and/or the buffer beam; wherein two tensile group strain gages of FX are arranged on two buffer beams which are oppositely arranged, and two compressive group strain gages of FX are arranged on the other two buffer beams which are oppositely arranged; two tension group strain gages of FY are arranged on two opposite buffer beams, and two compression group strain gages of FY are arranged on the other two opposite buffer beams.
  3. 3. The six-dimensional force elastomer with structural decoupling capability of claim 1, wherein the composite elastic beam comprises four vertically distributed elastic beams, wherein: The two opposite ends of the elastic beam are fixedly connected with the inner mounting block and the outer mounting ring respectively, and six groups of strain gauges are distributed at the corresponding positions of the elastic beam; and the elastic beam is provided with a concave part for arranging strain gauges of FX and FY in a high strain area above the surface stress mean value of the composite elastic beam.
  4. 4. A six-dimensional force elastomer with structural decoupling capability according to claim 3, wherein the recess comprises grooves symmetrically arranged on opposite sides of the same elastic beam, and strain gauges of FX, FY are distributed beside the grooves; or the concave part comprises through holes which penetrate through two opposite surfaces of the same elastic beam, and strain gauges of FX and FY are distributed beside the through holes.
  5. 5. A six-dimensional force elastomer with structural decoupling capabilities according to claim 3, wherein each of said elastic beams is a separate beam structure or each of said elastic beams comprises more than two beams; when the elastic beam comprises more than two Liang Zhushi, two beams and columns in the same group are arranged along the corresponding side wall of the inner mounting block, and a spacing hole is formed between the two beams and columns.
  6. 6. The six-dimensional force elastomer with structural decoupling capability according to claim 1, wherein the strain gages of FX, FY are arranged in a high strain zone above the composite elastic beam surface stress mean when subjected to a single load in FX direction or FY direction; At rated uniaxial load, the output of any one target measurement channel is 100%, and the output of the other five non-target channels is less than 2% of the full range of the non-target channels.
  7. 7. The six-dimensional force elastomer with structural decoupling capacity according to claim 1, wherein the composite elastic beam is provided with a finished plane, and the 24 strain gauges are symmetrically arranged on the plane on the same side or two opposite sides of the composite elastic beam.
  8. 8. The six-dimensional force elastomer with structural decoupling capability according to claim 1, wherein the strain gauge is a metal foil gauge, a silicon gauge or a thick film resistor, and each bridge satisfies an initial balance condition R1/r2=r3/R4 when no load is applied; Wherein R1, R2, R3 and R4 represent resistance values of four bridge arms in the Wheatstone full bridge circuit, and correspond to four strain gauges of each measuring dimension respectively.
  9. 9. The six-dimensional force elastomer with structural decoupling capability of claim 1, wherein the elastomeric material is stainless steel, aluminum alloy or titanium alloy.
  10. 10. A six-dimensional force sensor comprising a six-dimensional force elastomer with structural decoupling capability according to any one of claims 1-9, a power supply module for providing excitation voltages to each bridge, a signal conditioning circuit for amplifying the differential signals output by each bridge, and a housing.

Description

Six-dimensional force elastomer with structural decoupling capability and force sensor Technical Field The invention relates to the technical field of force sensors, in particular to a six-dimensional force elastomer with structural decoupling capacity and a force sensor. Background The core performance index of a six-dimensional force sensor is the degree of decoupling between the precision and dimensions. Conventional elastomers (e.g., cross beams, stewart structures, etc.) are limited by mechanical coupling, which when stressed in a single direction, can produce crosstalk signals in multiple measurement channels. The coupling generally needs a complex calibration matrix and a software algorithm to compensate, not only increases the complexity and cost of the system, but also may introduce problems such as temperature drift, nonlinearity, long-term stability, and the like. The inventors have found that the prior art has at least the technical problem that it has been attempted to reduce the coupling by structural optimisation, but that it is difficult to achieve complete decoupling over a wide range. For example, some designs employ over-constrained structures or partially flexible hinges, but still produce significant coupling errors under high loads or compound stresses. In addition, the attachment location and bridge connection of the strain gage will further exacerbate signal crosstalk if not exactly matched to the structural strain field. Therefore, a six-dimensional force elastomer which is cooperatively and optimally designed from the generation of mechanical strain to the whole process of electric signal conversion is urgently needed, and high-precision decoupling in a hardware level is fundamentally realized. Disclosure of Invention The invention aims to provide a six-dimensional force elastomer with structural decoupling capacity and a force sensor, so as to solve the technical problems of serious coupling problem and larger measurement error of the six-dimensional force sensor in the prior art. The preferred technical solutions of the technical solutions provided by the present invention can produce a plurality of technical effects described below. In order to achieve the above purpose, the present invention provides the following technical solutions: The invention provides a six-dimensional force elastomer with structural decoupling capability, which comprises an inner mounting block, an outer mounting ring and a plurality of groups of composite elastic beams which are coaxially arranged and are connected with each other, wherein: the composite elastic beam is provided with at least 6 groups of 24 strain gauges, wherein six groups of the strain gauges are respectively used for measuring forces in FX, FY and FZ directions and moments in MX, MY and MZ directions, each group of the strain gauges are electrically connected according to a corresponding Wheatstone full bridge circuit topology to form six independent measuring bridges, and tension and compression polarities of the strain gauges in each group are defined according to the strain directions of the strain gauges under corresponding forward loads and correspond to bridge arm positions in the circuit topology; The structural shape of the composite elastic beam, the arrangement position of the strain gauge and the connection relation of the strain gauge in the full bridge are matched, so that when the elastic body bears load in a single target direction, the strain distribution of the target channel strain gauge enables the full bridge output of the elastic body to meet the formula of Vout (VinxGF/4) x (epsilon 2+ε3- ε1-ε4), the absolute value of the combination term is sufficiently large, and the strain distribution of the non-target channel strain gauge enables the full bridge output of the elastic body to be sufficiently minimized due to low strain isolation or bridge self-balancing mechanism; wherein, the bridge self-balancing mechanism means that the strain distribution of the non-target channel meets epsilon < 2+ > epsilon < 3+ > epsilon < 1+ > epsilon < 4 >, so that the output of the bridge self-balancing mechanism approaches zero, and the coupling error is less than or equal to 5%; Wherein Vout represents the output voltage of the Wheatstone full-bridge circuit, vin represents the excitation voltage of the Wheatstone full-bridge circuit, GF represents the sensitivity coefficient of the strain gauge, and ε 1、 ε2、 ε3、 ε4 respectively represents the strain value generated by each group of four strain gauges when being stressed. Preferably, the composite elastic beam comprises four elastic beams and eight buffer beams which are vertically distributed, wherein: the ends of the eight buffer beams are fixedly connected with the inner wall of the outer mounting ring to form a regular octagonal frame, and the opposite ends of the elastic beams are respectively and fixedly connected with the inner mounting blocks and the corresponding ends of